Original Title: Summary of Detailed Steps for Knowledge Popularization and Daily Preservation of Down-the-Hole Drilling Tools Size selection of down-the-hole impactor, drill bit and drill pipe The size of the down-the-hole impactor depends mainly on the hole diameter and the rock type. For blasting holes, the hole diameter range of down-the-hole drilling is from 89mm to 252mm, the hole diameter less than 89mm is mainly the top hammer type, and the multi-purpose rotary drilling mode with a hole diameter greater than 252mm is mainly selected. Generally speaking, the smallest hole size that a down-the-hole impactor can fit is its nominal size, which means that the smallest hole size that a 4-inch impactor can fit is the 4-inch hole size. Generally speaking, in this case, there is enough annular space between the impactor and the hole wall, and between the drill pipe and the hole wall for slag discharge. The maximum size of the matching bit is the size of the impactor plus 1 inch. For example, the maximum bit size to match a 4-inch impactor is 5 inches. The outer diameter of the drill pipe and the outer diameter of the impactor are as close as possible, which can ensure better slag discharge and reduce the possibility of sticking. In terms of the processing technology of drill pipe, the surface finish and dimensional accuracy of cold-drawn pipe are superior to those of hot-rolled pipe. Good surface finish means that the surface of the steel pipe is not prone to peeling, and the metal chips caused by peeling will reduce the service life of the impactor. In addition, if the connection part of the thread of the drill pipe and the main body is welded by friction, the strength of the drill pipe can be increased, and meanwhile, if the heat treatment of the thread part is well done, the reliability and strength of the thread can be increased, so that the connecting and disconnecting rod is smoother, and the working efficiency and the total perforation speed are improved. Select the appropriate down-the-hole bit Looking at the drill bit, the main body of the drill bit is usually machined from cemented carbide, then heat treated to the specified hardness, so that the surface compressive stress has enough fatigue resistance, and then embedded with cemented carbide drill teeth. The convex, sharp-tooth bit design provides the fastest drilling efficiency and is most suitable for medium-soft rocks with low grindability. For hard rock with high grindability, the flat drill bit can improve the life of the drill bit. If the outer edge of the button is large enough, the life of the drill bit can be improved and the use cost can be reduced by grinding the drill bit for many times. In addition, the concave button bit can also be applied to such hard rock with high grindability. Expand the full text As shown in the figure below, the concave drill bit is more suitable for medium hard rock with developed joints and many fissures, which can effectively reduce the probability of hole deviation, which is also mentioned in the previous article series. Practical application Drills in open pit mines and quarries usually require relatively durable down-the-hole impactors, because quarries are usually long-term operations, and it is not cost-effective to replace impactors frequently. Some of the better down-the-hole impactors can be repaired and used many times before they are completely replaced, such as changing the direction of the outer tube of the impactor. The straightness of the hole is more important for the drilling of building stone (marble, etc.). In the drilling of holes larger than 89mm, the straightness of the down-the-hole type is usually better than that of the top-hammer type. Exploration drilling needs to be carried out in remote sites with poor facilities. Therefore, the requirements of Dth impactor are simple design, high reliability, and to adapt to high wind pressure drilling. Reverse circulation percussion drilling is also commonly used, and this sampling method is relatively cost-effective for diamond core drilling. The reverse circulation impactor uses the same process as the common down-the-hole impactor, but the reverse circulation drill pipe is used. High-pressure air is blown through the gap between the inner wall and the outer wall of the drill pipe, and then the cuttings are discharged from the inner wall of the drill pipe, and then the cuttings are collected with a dust bag, as shown in the following figure. In actual use, there is always an important factor to consider, that is, the rig operator. An experienced driller can effectively adjust the drilling parameters to reduce the probability of impactor failure and improve the life of the impactor. There are a variety of impactor options on the market, both inexpensive and high-end. However, the value of impactor is not only measured by its material and design itself, mining dth bit , but also by the balance between the efficiency brought to users and the cost of rock and rice. For example, an impactor is very cheap and durable, but the fuel consumption is very high, the result is that the cost of rock rice is very high, which can not be said to be a good impactor. Another impactor is very expensive, but the efficiency is also high, and the cost per rock meter is low, so this is a good impactor. Of course, as a user, we also need to consider whether the impactor manufacturer can provide sufficient technical support and use guidance, which is also very important, and can effectively help our users improve drilling efficiency and reduce the use cost. Preservation of drill pipe First, blow to remove the water inside the drill pipe, and open the bit shank lubricating device at the same time. In principle, it is better to see the bit shank lubricating oil at the bottom of the drill pipe. Second, the outside of the drill pipe, including the threaded portion and the main body of the drill pipe, must be wiped clean. At the same time, a rubber cover (as shown in the figure below) should be added to the male and female joints to prevent pollutants from entering. Storage and reactivation of impactors For short-term storage, follow these steps: First, blowing to remove the water in the impactor; Condly, filling 1 liter of bit oil from the upper joint part; Third, turn on the air and blow for about 10 seconds, so as to fully lubricate the internal parts of the impactor; Fourthly, like the drill pipe, the upper joint and the lower joint are respectively covered with a rubber cover; Fifth, place the impactor horizontally in a dry environment. Long-term preservation, slightly different First, blowing to remove the water in the impactor; Second, loosen the upper joint and the lower joint, and disassemble the impactor; Third, check and wipe all the internal parts, preferably in a clean room; Fourth, properly lubricate all parts with proper lubricating oil; Fifthly, assemble the impactor and cover the upper and lower joints with a rubber cover; Sixth, place the impactor horizontally in a dry environment. Reactivating the impactor requires the following three step First, disassemble the impactor and inspect all the internal parts. If it is found that the surface of some parts is oxidized, it is necessary to polish the oxidized parts with sandpaper. If the impactor is put into use without testing, it is likely to cause premature failure of the impactor. Second, clean the parts, wipe them clean and lubricate them. Thirdly, the cleaned and lubricated parts are assembled into an impactor, which can be put into use. Read the above article, may be a lot of people think, we usually put casually, do not still use?! Many users will record the wear and tear of drilling tools, such as a hammer used for several months and so on. In today's market depression and fierce competition, the price of rock drilling has been declining. Xiaobian suggests that our majority of down-the-hole drilling rig users can try to work hard on maintenance, such as using and preserving drilling tools according to our suggested methods, carrying out reasonable maintenance and lubrication in strict accordance with the requirements, and trying to see if the life of drilling tools can be longer than before, so as to help you save more money. Machines are more reliable than people. If you are good to machines, machines will be good to you. Reprinted from the network,dth drilling hammer, the copyright belongs to the original author, if there is infringement, please contact to delete! You see this article with · Return to Sohu to see more Responsible Editor:. wt-dthtools.com
09:42
How to deal with the
Original title: How to deal with the verticality deviation of bored pile with rotary excavator? [Abstract] Various rotary drilling rigs are widely used in the field of pile foundation construction at home and abroad, but in the process of construction of bored piles by rotary drilling rigs, the verticality deviation of pile body is often large, which can not meet the design requirements. Therefore, the control of pile verticality is of great significance in this process. This paper analyzes the reasons for the verticality deviation of bored piles with rotary excavator, and puts forward the corresponding control measures. [Key words] Rotary pile driver; Verticality; Bored pile; Control; 1. Project overview 1.1 Project overview Taking Fochen Road Rapid Reconstruction Tunnel Project as an example, the project adopts open excavation construction, the depth of foundation pit is more than 3 meters and less than 5 meters, and the supporting structure adopts φ 0.7m@0.5m cement-soil mixing pile gravity retaining wall support; If the depth of the foundation pit is more than 5 meters and less than 11 meters, it shall be supported by φ 1.0m@1.2m bored piles and single row of φ 0.7m@0.5m cement-soil mixing piles. If the depth of the foundation pit is greater than 11 meters, it shall be supported by φ 1.2m@1.4m bored piles and single row of φ 0.7m@0.5m cement-soil mixing piles. 1.2 Engineering hydrogeological conditions According to the lithology revealed by the borehole, the rock and soil are divided into the following layers: (1) artificial fill layer, with an average thickness of 4.55 m; (2) fluvial facies impact clay layer, with an average thickness of 1.60 m; (3) marine and continental facies sedimentary layer, with a average thickness of 6.57 m; (4) alluvium, with a thickness of 5.40 m; and (5) residual soil layer, average thickness 9.68 m; and (6) bedrock. The measured water level is the mixed water level of pore water and bedrock fissure water in the fourth quarter, and the buried depth of the water level is 1.79 ~ 5.50 m. 1.3 Test pile condition According to the design requirements, the bored piles constructed by the rotary pile driver shall be tested,dth rock bit, and the rotary single-door bottom bucket without air holes shall be used for the test pile. It is specified that the verticality deviation of the pile is 1% [1]. The verticality deviation of 3 out of 6 completed test piles is greater than 1%, and the failure rate reaches 50%. 2. Importance of verticality control The verticality control of piles is of great significance to the subsequent construction of foundation pit.If the verticality deviation of bored piles around the foundation pit is large, it will lead to uneven stress of the retaining structure around the foundation pit, which will bring great hidden dangers to the safety of the foundation pit. At the same time, if the verticality deviation of the bored cast-in-place pile is large, it will have a greater impact on the construction and use of the main structure in the later period. Because of the large verticality deviation of the bored cast-in-place pile around the main structure, the stress around the main structure will be uneven,dhd drill bit, which will lead to cracks in the main structure and bring hidden dangers to the subsequent use of the main structures. 3. Reasons for deviation of verticality The verticality deviation of the test pile is large. Through the analysis of the actual engineering project, the following reasons are summarized from the mechanical selection to the final hole formation: 1. Selection of drill bit. During the drilling process of the rotary pile driver, the geological hardness is uneven, and the selection of drill bit can not meet the needs of different geological conditions, resulting in the deviation of the drill bit, and then the vertical deviation of the pile does not meet the requirements of the specification. 2. Deviation of casing embedment. Expand the full text 3. Displacement of drill pipe occurs during drilling. 4. The positioning of the reinforcement cage is deviated due to the improper setting of the cushion block for controlling the reinforcement cage, the deviation caused by the lack of centering review after the reinforcement cage is in place, the deviation caused by the rapid pouring of concrete or the deviation of the steel cage caused by the hanging of the conduit. 4. Control measures for verticality deviation 4.1 Selection of drill bit Select the drill bit according to the formation conditions: 1. Clay: the rotary drilling bucket with single-layer bottom shall be selected. If the diameter is too small, the two-part bucket or the drilling bucket with unloading plate can be used. 2. Silt, soil layer with weak viscosity, sandy soil, and pebble layer with poor cementation and small particle size: select the drilling bucket with double bottom. 3. Hard daub: select rotary drilling bucket with single soil inlet (single and double bottoms) or straight screw with bucket teeth. 4. Cemented gravel and strongly weathered rocks: conical auger bits and rotary drilling buckets with double bottoms shall be provided (single port for larger particle size and double port for smaller particle size). 5. Stroke bedrock: rotary drilling bucket equipped with cutter barrel coring bit, conical auger bit, double bottom, Tapered Rock Bit ,dth hammer bit, or cutter straight auger bit, double bottom. 6. Slightly weathered bedrock: If the diameter of the rotary drilling bucket equipped with cone barrel coring bit and conical auger bit with double bottom is too large, the grading drilling process shall be adopted. The single-layer bottom drilling bucket without air holes is used for the test pile. Since it is only applicable to the soil layer with strong viscosity, the soft and hard geology in the project is uneven, and there are slightly weathered and moderately weathered bedrock in the deeper part, which leads to the deviation of the drill bit during the construction of the rotary pile driver, and then leads to the deviation of the verticality of the pile body. 4.2. Pile casing embedment Before the steel casing is buried, accurate measurement and setting out shall be carried out to ensure that the deviation of the top surface of the steel casing is not greater than 5cm, and the inclination of the steel casing shall not be greater than 1% during the burial; the drilling rig shall be in place, and the drill bit shall be accurately aligned with the pile position. Before the steel casings are buried, the drill bit with big bore shall be used to pre-drill to the elevation of the casing bottom, and then the auxiliary winch of the drilling rig shall be used to lift the casing into the hole. The drilling bucket is lifted out and the steel casing is pressed into a predetermined position with the drilling bucket. In order to maintain the verticality of the pile casing when the pile casing is buried, the intersection control shall be carried out with different distances from the pile to the pile center until the top of the pile casing reaches the specified elevation. After the pile casing is buried, restore the position of pile center according to the distance and the previously determined direction, and check whether the pile casing center coincides with the pile center, and control it within ± 5 cm. At the same time, tamp the surrounding of the pile casing to make it stable without deviation and collapse in the drilling process. 4.3 Drilling process Bored piles shall be drilled slowly after opening, so as to form a good and stable retaining wall and ensure the correct hole position. During the drilling process, the drill pipe position shall be regularly checked with the distance intersection, and the deviation shall be adjusted immediately until the hole position is finalized. Before the drilling operation, the mast needs to be positioned and set, and during the operation, the mast also needs to be adjusted vertically. Vertical adjustment can be divided into manual vertical adjustment and automatic vertical adjustment. The automatic verticality adjustment can only be carried out through the automatic verticality adjustment button on the display within the ± 5 ° range of the relative zero position of the mast; when the mast exceeds the ± 5 ° range of the relative zero position, the verticality can only be adjusted manually through the inching button on the display or the electrical handle on the left operation box. In the process of vertical adjustment, the position status of the mast can be monitored in real time through the working interface of the mast on the display, so that the mast can finally reach the set position for hole forming [2]. 4.4 Positioning of reinforcement cage Pile verticality deviation detection is determined by the deviation between the center of the reinforcement cage and the design pile center, so the positioning of the reinforcement cage is an important item in the control of pile deviation. (1) When lowering the reinforcement cage, two hanging bars shall be used to ensure the verticality of the reinforcement cage after lifting. (2) Add protective cushion blocks according to the specification requirements, especially add more protective cushion blocks at the top of the pile. And (3) aft that reinforcement cage is lowered into the hole, pul a cross line on the framework reinforcement of the reinforcement cage to determine a center point, performing distance intersection to restore the center of the pile position through the guide pile and the set direction, compare a hanging vertical line with the center of the reinforcement cage, performing adjustment by slightly moving the reinforcement cage through a crane to ensure that the two centers are superposed, welding a positioning bar to enable the positioning bar to abut against the wall of a protective cylinder, O as to achieve the purpose of stabilizing the reinforcement cage. If the pile top is far away from the top of the pile casing, the false cage shall be welded to the top of the pile casing, and the above method shall be used for positioning. It shall be noted that the false cage shall have certain rigidity. (4) When the poured concrete is close to the reinforcement cage, slow down the concrete pouring speed, and the normal pouring speed can be restored when the bottom of the conduit is raised to more than 2 m above the reinforcement cage, so as to ensure that the reinforcement cage will not float up and deviate due to the recoil force of the concrete, and at the same time, the conduit is located in the center of the hole to avoid deviating to one side. In order to avoid the displacement of the skeleton caused by the uneven reaction of the concrete during the pouring process. 5. Conclusion Because of the many advantages of rotary drilling, it is more and more widely used in the field of pile foundation construction,fastest dth hammer, and constantly summarizes the measures to control the verticality of pile position in the construction process, which is of great significance to the construction technology of bored pile with rotary drilling machine. References [1] Standard for Quality Inspection and Evaluation of Highway Engineering (JTGF80/1-2004) [2] Luo Yu. Application of Rotary Pile Digging Machine in the Construction of Foundation Pit Supporting Pile . Guangdong building materials ，2008（6） Source: Architecture and Culture: Academic Edition, 2013 (8): 114-114 By Li Zhihong Return to Sohu to see more Responsible Editor:. wt-dthtools.com
Original title: What is the drilling technology of PC endurance board? As a good building material and equipment,mining dth bit,rock drilling tools, PC endurance board has high strength and durability. Even though it is very good, Borehole Drill Bits ,overburden drilling systems, it also causes losses to users due to a wrong construction method of cracks along nail holes. Therefore, drilling in PC endurance board is a very important technology. Considering that the raw material of the polycarbonate solid sheet will show thermal expansion and shortening, and thus its fixing time has a significant effect, the possibility of quality problems after the item is very high if the nails fixed on the board are not opened directly. It is necessary to pull the extension to reduce the failure rate of the solid board. So, how to process the PC endurance board-drilling operation? The simple way is to use the solid piece piercing bit directly, which can pick a thicker bit. ? Larger or wobbly holes. The diameter of the hole diameter is about two thirds larger than the left and right of the nail being drilled. The rear number is preferably larger. Return to Sohu to see more Responsible Editor: (function() { function getBrandHtml() { var brands = [],down the hole bit, html = ''; for(var i = 0; i < brands.length; i++) { var brand = brands[i]; if(brands.length i+1) { html+= ''+brand.name+''; } else { html+= ''+brand.name+'、'; } } return html; }; if(document.getElementById('linkBtn')){ document.getElementById('linkBtn').onclick = function() { $('#brands').removeClass('brand');$ ( '# tipInfo').text ( 'Real name responded'); $ ('#linkBtn').remove();$ ('.real-response .content').css('line-height', '20px');$ ('.real-response .time').css('line-height', '20px'); }; document.getElementById('brands').innerHTML = getBrandHtml(); }; })();。 wt-dthtools.com
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09:42
Analysis of the Most
Original Title: Analysis of the Most Complete Stone Mining Technology and Equipment in History The most complete stone mining technology and equipment in history For your reference. This article is divided into four sections for you to sort out. The article is long, so you can collect it first. Read patiently, welcome to forward and share! [Types and Elements of Stone Mines] [Deposit development and development transportation method] [Mining process of stone deposit] [Classification of Mining Methods for Stone Mines] [Types and Elements of Stone Mines] I. Types of Stone Mines The types of stone mines include open-pit mining and underground mining. Open-pit mining is divided into hillside open-pit mining, sunken open-pit mining and well mining. Underground mining is divided into cave mining and shaft mining. 1. Open-pit mining: A stone mine in which the overburden and weathered layer on the surface of the stone ore body need to be stripped before mining. An open trench is dug from the ground and a working face is created to extract the block from the working face. According to the topographic conditions of deposit burial, the mining above the lowest level of stope surface is called hillside open-pit mining; the mining below the lowest level of stope surface is called depression open-pit mining. Open-pit mining on hillside: Basically according to the principle of top-down mining sequence. Expand the full text Hillside open-pit mine Open pit mining: Basically according to the principle of top-down mining sequence. Sunken open-pit mine Well-type mining: In fact, it is a special case of open pit mining. With the deepening of stone mining operations, many stone mines have gradually evolved from hillside open-pit type to depression open-pit type, and eventually to well mining. The depth of many well-type mines in foreign countries exceeds 50 meters, or even reaches 80 meters or more. Portuguese pink marble CARRARA, Italy 2. Underground mining: Stone mines that need to be excavated from the surface to reach the ore body can be divided into roadway (cave) mining and chamber (roadway) mining. Cave type: Open-pit mines with steep mountain shape, large amount of stripping and extremely dangerous mining operations, such as some marble mines in Baoxing County, Sichuan Province; sunken open-pit mines with inclined ore bodies, with the increase of mining depth, need to strip a large thickness of overburden, such as white marble mines in Fangshan, Beijing; With the increase of mining depth, the mining of some well-type marble mines will not be able to continue. The cave mining method will make the mining operation more practical. The main mining process is similar to that of the sunken open-pit mine, but the difference is that a rectangular channel development process is added before the formal mining, and a new free surface is developed on the ore body with only one free surface. 1997 CARRARA Marble Mine-4 (Tunneling) Shaft type: Use the roadways left by other engineering, transportation facilities or mining projects to pass through the stone mines excavated inside the roadways. II. Composition elements of open pit 1-Work platform 2-Safety Platform 3-Cleaning platform 4-Transport channel α, β-final slope angle GF-Lower final line of open pit H-Final mining depth of open pit AB-Upper final boundary line of open pit ABGHF-Final state of open pit 1. Bench: When stone is mined in the open pit, the ore body to be mined is usually divided into horizontal layers with a certain thickness and mined layer by layer from top to bottom. When two or more horizontal slices are mined at the same time, a certain advance distance shall be kept between the upper and lower slices. A step shape is formed in the space during the mining process and at the end of the mining process. These step-like working surfaces are called steps. The bench is the basic element of the stone open pit, and also the unit of the independent quarry operation. 2. Working platform: horizontal part of each step 3. Safety platform: the stope boundary is reserved to ensure the safety of the lower production platform and the stability of the slope. 4. Cleaning platform: one cleaning platform shall be set every 2-3 safety platforms. 5. Transportation channel: transportation road between the ground and each horizontal layer. [Deposit development and development transportation method] I. Deposit development (transportation system) 1. Concept: It is a transportation channel connecting each working bench inside the mine to the block yard or the external transportation system and the waste rock yard, and plays a role in preparing various tunnel projects of new mining level in time. Set up a connection stone quarry. Engineering of the transport system of the yard and transport ground 。 2. Tasks: (1) The mined blocks are transported outward or sent to the block yard. (2) Transport the waste rocks and muck to the waste rock yard (3) Transport tools, materials, equipment and personnel into or out of the working face. Straight Ditch Road Transportation System of Blue Pearl Granite Mine in Norway Larvik Mine, Norway II. Development of transportation methods 1. Highway development and single automobile transportation Applicable conditions: simple terrain, (few bends, large radius), small stope height difference, large range, convenient for highway line development, large block specifications, large transportation volume, and small highway capital construction quantities. 2. Applicable conditions for transportation and development of slope winch Mines with complex terrain, large elevation difference (20º ~ 40º
, small mining area, hillside or sunken mining area with difficulty in highway development to transport blocks with small size, and small amount of waste rock and soil. The slope hoist is generally located outside the mining boundary. In the stope, the blocks need to be loaded on the trolley by other means of transportation. 3. Applicable conditions for joint development of fixed mast crane and truck transportation Mines with large stope height difference, small range, complex terrain, difficult road development, and less waste rock and dregs. The mast crane is usually located at the edge of the stope. The blocks outside the hoisting range shall be transported to the hoisting range of the mast crane by the traction winch or loader, and then lifted to the truck of the transport platform by the mast crane. 4. Development of aerial ropeway transportation The rope crane is used to complete the loading, lifting, transportation and loading operations at one time. Applicable conditions: stone mines with complex and steep terrain, large elevation difference, deep valleys, difficult highway development, large investment, small scale and small block size. 5. Applicable conditions for open chute transportation and development The terrain is complex, the elevation difference is large, the slope is steep (greater than 40º, and there is a shortage of capital construction funds. 6. Joint development [Mining process of stone deposit] The mining process is divided into seven processes: Stripping — Separation — Top turning — Segmentation — Shaping — Hoisting and transportation — Slag removal and waste discharge 1. Stripping 1. Basic concepts (1) Stripping range: all parts within the mining range that do not meet the processing and use requirements; (2) External stripping: the stripping of the surface and surrounding parts of the mineable ore body that do not meet the processing and use requirements before the mining of the deposit, so as to expose the mineable parts; (3) Internal stripping: the stripping of the part inside the ore body that cannot become blocks due to the existence of joints,DHD Drill bit, fissures and vein rocks. (4) Stripping ratio: refers to the ratio of the amount of earth and stone stripped to the volume of block mined. (5) Block rate: the ratio of the volume of blocks mined within a certain mining range to the volume of raw ore within the range is called the block rate. 2. Basic principle: simultaneous mining and stripping, stripping first 3. Requirements: The integrity and block formation of the ore body shall not be affected. Butterfly Green (XIII) II. Separation-the main process of stone mining 1. Concept: separate the strip-shaped block stone with a volume several times that of the block from the ore body. 2. Requirements: (1) Do not damage the ore body and ore-take protective measures (2) The specification size of the strip block stone shall be equal to the integral multiple of the specification size of the block plus the processing amount required for dividing the block. (3) According to the natural conditions of the ore body, make full use of natural fissures and bedding. (4) According to the technical performance of the mining equipment, give full play to the role of the equipment, improve efficiency and reduce costs. The width of the strip block stone is generally the height of the mining bench, and the length is a part of the mining bench. Three, top turn over-fall stone 1. Purpose: It is convenient to divide into blocks according to the required specifications. 2. Method: traction winch, loader, top stone machine, water pressure package and air pressure package. 3. Key points: use protective measures to prevent the stone from breaking when it is overturned. The kerf width of diamond saw mining is only 12 mm. When all the stones are separated from the ore body, it is very difficult to move or overturn the stones weighing hundreds of tons from the ore body directly through the 12 mm kerf. At present, domestic stone mines generally adopt the method of drilling a 25 × 25 × 50cm stone trough on the parent ore body and placing a hydraulic stone jacking machine to separate the stone from the displacement, which destroys the integrity of the ore body after the trough is drilled and affects the outturn rate of the ore body behind. New technology of air pressure pushing bag: The pneumatic pushing bag is inserted into the 12 mm saw kerf formed by the beaded wire sawing, and the compressed air is used to inflate the bag, so that the bag expands to generate dozens of tons of thrust, and the lever principle is used to push the stone to move or turn it over, so that the stone can be disintegrated in the subsequent process to produce blocks. The bag body is made of high-strength polymer rubber material and can be repeatedly stretched and used. Air pressure push bag (I) Air pressure push bag (II) Air pressure push bag (III) 4. Partition Dividing the strip block stones into rough blocks or blocks on the overturned strip block stones according to the specification of the required blocks. Quarry stone: a cuboid or cube with certain specifications and no cracks, which can meet the processing requirements of decorative plates. Rough block: the shape basically meets the specification requirements of the block, but the surface is uneven, with a positive error of more than 3,dth drill bits, and the block stone needs to be shaped. Metering block: the actual metered volume of the block after inspection. It is the actual effective volume of the block after deducting the excess volume caused by the size deviation. Methods: Chiseling, splitting, sawing, mechanical drilling and cutting, controlled blasting. Five, plastic surgery 1. Purpose: Trim the rough blocks into blocks that meet the requirements of specifications, so as to reduce the redundant workload in hoisting, transportation and processing and reduce the cost. For example, if the top surface of granite blocks is shaped and leveled by a fixed bead saw, the total error of the flatness is within 2cm, and the total error of the flatness only by manual leveling is up to 10 cm, and the time required for the saw blade of a sand saw to complete the "cut-in" stage is nearly doubled. 2. Method: wedging, splitting and sawing According to the shaping method, the blocks are divided into two categories: a. Saw face block (SS): All six sides are blocks shaped by the sawing method. b. Split face block (CS): Block with one or more sides shaped by chiseling 3. Shaping equipment: Large diameter circular saw, chain arm shaping machine, diamond band saw shaping machine, bead saw shaping VI. Hoisting and transportation 1. Mast crane (mast crane) Large lifting capacity, wide service range, strong adaptability, easy operation, high equipment price, large installation or displacement workload, slow lifting speed. The maximum lifting weight of 50 tons means that 18 cubic meters of block can be lifted. 2. Truck (wheeled) crane Need to install fixed feet, poor road adaptability, large tire loss, small lifting capacity, strong flexibility and versatility. 3. Crawler crane Can be directly hoisted, does not need to install fixed support legs, and has strong adaptability to roads, large lifting capacity and strong flexibility. Crawler crane 4. Front end loader: The multipurpose mining equipment can be used for shoveling, stripping, hoisting, hauling, cleaning working steps, prying stones and other operations. 5. Crawler excavator: As above, the front end is the loading device and the rear end is the digging device. 6. Gantry crane A crane of the bridge type in which a horizontal bridge is set on two legs to form a gantry. Gantry crane 7. Cable crane A bridge crane in which the trolley travels on a carrying rope. 8. Traction winch (1) Mine multi-purpose equipment can be used for: ① Traction power of slope winch ② Pull the blocks to the working range of the lifting equipment ③ Expanding joints and pouring stones ④ Power of lifting equipment (2) Operation mode: Various hauling operations can be completed by configuring different pulleys. VII. Slag removal and waste discharge Before the construction of stone mines, it is necessary to consider the construction of a dregs yard with sufficient capacity, which is a necessary preparation for continued production and safe production. Attention should be paid to the protection of resources, the protection of the environment, the comprehensive utilization and the improvement of efficiency. According to the requirements of the Technical Specification for Decorative Stone Open-pit Mines, Mining Drilling Equipment ,mining drill bit, the comprehensive recovery rate of decorative stone mines should not be less than 50%. [Classification of Mining Methods for Stone Mines] I. Mining method: Splitting, blasting, cutting, burning, etc. II. Selection basis of mining method: 1. Geological conditions of the deposit: joint occurrence, development degree, orebody shape … The thick orebody is favorable for mechanized mining, and the thin orebody is suitable for manual mining. Chisel hole splitting method should be used if the fissures and joints are developed and irregular 2. Rock type For example, basalt and gabbro without quartz can not be cut by flame, and the compressive strength of the rock is about 30 times of the tensile strength and 10 times of the shear strength. The splitting wedge is used to produce compressive tension on the rock to break the rock, which is especially suitable for deposits with developed horizontal joints and fissures. 3. Mine scale: 4. Specifications of blocks required: 5. Physical and geographical conditions: 6. Environmental protection requirements: 7. Technical and economic indicators: 8. Output, efficiency and benefit: Chisel split method I. Splitting mechanism and applicable conditions Mechanism: 1. The tensile strength of rock is relatively small. 2. The principle of "splitting" is applied to produce greater tension on the rock, and the rock breaks after being stressed. 3. When wedging, the action time of the force is short, the speed is fast, and the kinetic energy of the wedge is large. Applicable conditions: 1. It is applicable to rocks with nearly horizontal cracks. 2. The tensile strength of granite is less than that of marble, so it is more suitable for granite mining. 3. Rock is an anisotropic body with different tensile strengths in different directions, so the parameters of wedge holes are also different in different directions. 2. Artificial wedging and splitting method 1. Types and structures of tools-wedges A — Flat wedge; B — Pyramid wedge; C — Compound wedge 2. Operation method: hand-held rock drill For manual wedging and splitting of shallow holes and deep holes (rows of holes drilled on the splitting surface), the spacing between rows of holes is related to the splitting performance, and the minimum spacing is only 10-15 cm 3. Advantages and disadvantages: simple tool, simple method and low cost The labor intensity is high, the efficiency is low, the squareness of the block is poor, and the shaping workload is large. When mining granite, it is generally necessary to drill 10 meters of holes for each cubic meter of total ore and rock. According to the calculation of 30% of the block rate, it is necessary to drill 30-40 meters of holes for each cubic meter of finished block. Shallow borehole artificial splitting Disintegrating large granite material by artificial splitting method Shaping granite blocks by artificial splitting method Deep hole manual splitting mining disintegration separation body III. Splitting method of hydraulic splitting machine The principle is the same as that of manual splitting, which usually refers to the use of hydraulic splitters and deep-hole splitting for mining. Compared with the manual wedging method, the method ensures the consistency of hole arrangement and splitting, reduces the labor intensity and improves the efficiency. During operation, a drill hole for placing the hydraulic composite splitting wedge is drilled on a rock by a rock drill according to the presplitting direction, the hydraulic composite splitting wedge is placed in the hole, the splitting wedge and a hydraulic pump station are connected, high-pressure oil is transmitted to a hydraulic splitting head through an oil pipe, the hydraulic splitting wedge generates extrusion tension to two walls in the hole under the action of the high-pressure oil, and the rock is broken after being stressed. Borehole blasting method Applicable conditions: for all kinds of rocks with few natural fissures, separate large stones from rock mass by slight blasting Classification of methods: It can be roughly divided into ordinary blasting, conventional controlled blasting and grooved controlled blasting. Advantages: simple operation, high efficiency, strong applicability and low cost Disadvantages: poor squareness, low block rate, reduced stone strength, and many unsafe factors I. Ordinary blasting method 1. Agent: black powder 2. Blasting parameters: Hole diameter: 30 ~ 40 mm Hole spacing: horizontal hole spacing: 1 ~ 1.5m; Vertical pitch: 0.8 ~ 1.2m Hole depth: horizontal hole depth: 45 ~ 60% of separation block width Vertical hole depth: 60 ~ 80% of the height of the separation block Charge: 20 ~ 25% of hole depth Detonation: detonator or electric detonator Note: Measures to prevent excessive concentration of blasting force: Block charge and gun hole should not be packed too tightly II. Controlled blasting 1. Concept: Controlled blasting is a kind of precisely designed blasting with different explosives and ignition methods, which can not only achieve the desired effect, but also control the hazards caused by blasting within the specified allowable range. This kind of blasting with dual control of blasting effect and blasting hazards is called controlled blasting. 2. Agent: Black powder, detonating cord, No.2 rock explosive, blasting tube, metal incendiary agent, static expansion agent (1) Detonating cord: It takes the single substance high explosive RDX or TEK as the core, and its external image is the fuse, slightly thin, and the color is mostly red. The explosive charge of the detonating cord in China is 12 ~ 14 G/m, and the detonation velocity is 6500 ~ 6800 m/s. It can be detonated by fire detonator or electric detonator, and the hole spacing is 20 ~ 40. The internal drilling medium for placing the detonating cord can be air or water. Mining site by detonating cord controlled blasting (2) Metal incendiary agent (high-energy incendiary agent): The metal oxidant reacts with the metal reducing agent to generate high-temperature expansion gas, and the rock is cracked under the combined action of the expansion pressure and the thermal effect. Such as: 2Al + 3MnO2 = Al2O3 + 3Mn + 221 kcal (or + 9.52 × 105 J) Commonly used oxidants: MnO2, CuO, Fe3O3 … Commonly used reducing agents: Al, Mg, Fe + Mg … (3) Static expansion agent: Calcium oxide, inorganic salt and organic additives, and the tension generated by the volume expansion of the reaction after adding water. Such as: CaO + H2O-Ca (OH) 2 + 15.5 kcal, with volume expansion of 3 times, the expansion stress is about 30 ~ 50Mpa (the tensile strength of rock is about 5 ~ 12MPa). Mechanical cutting method Concept: Separation of rock blocks or blocks directly from the rock mass with the aid of mechanical equipment in accordance with the required block specification The invention has the advantages of no damage to the ore body and the block, flat cutting surface, no need of shaping, high block rate, large block size, low labor intensity and high production efficiency. Advanced technology, technology and equipment. Common equipment: rock drill, steel cable stone sawing machine, diamond wire saw, chain saw, disc saw. 1. Steel cable stone sawing machine sawing method It appeared at the end of the 19th century and was used for marble mining with quartz sand as raw material. It was discontinued at the end of the 20th century. II. Diamond wire saw cutting method 1. Equipment composition: (1) Driving device (2) Diamond rope (3) Working column and guide wheel The steel wire rope is sealed by spring, injection molding, rubber injection, etc. Fixed diamond bead 2. Working methods: (1) Ring traction cutting method When the ore body has two or more free surfaces, a horizontal hole and a vertical hole are drilled along the designed sawing surface, so that the two holes are connected and on the same cutting surface. (2) Rope pressing and cutting method When the number of the free surfaces of the ore body is less than two, a hole is drilled on the working face of the bench, a rope pressing wheel is arranged on a multi-purpose drilling machine or a cutting upright post and is placed in the hole, and a carborundum rope bypasses the rope pressing wheel and forms a closed loop with a driving wheel of a sawing machine to work. Diamond wire saw traction cutting Diamond wire saw traction cutting 3. Applicable conditions of diamond wire saw It can be used for full sawing and mining of marble and granite or combined mining with other equipment; it can also be used for stone processing and block shaping. 4. Advantages and disadvantages The mining cost is high, but the sawing surface is flat, the sawing area is large, and the block rate is high 4. Sawing method of arm-type stone sawing machine According to the cutting tool, it is divided into: 1) fixedly instal a hard alloy or diamond segment cutting edge on a cutting arm transmission chain to form a hard alloy cut chain or a diamond cutting chain; 2) Polyurethane injection molded cutting tape with diamond cutting segments. The main body of the diamond cutting belt is a rectangular diamond segment threaded on six side-by-side stainless steel wire ropes for aviation, and the segments are all sealed by special polyurethane injection molding. BENETTI, Italy JB-990 mining band saw vertical cutting operation The vertical and horizontal cutting of the ore body can be carried out, and the vertical and horizontal cutting positions can be quickly and flexibly switched at the same installation position. It is suitable for the mining of soft stones such as marble, limestone and travertine with medium hardness. At present, the maximum vertical cutting depth of large chain arm saw can reach 8 meters, the longest horizontal cutting depth can reach 4.8 meters, and the chain width is generally 33.5 mm. The maximum cutting depth of the mining band saw can reach 4.8 meters, and the width of the saw gap is generally 38 mm. At present, the maximum vertical cutting depth of the arm saw has reached 8 m, and the mining bench with a height of 8 m can be mined. 5. Disc stone sawing machine sawing method A saw blade with a diameter of 4.2 m can be mined to a height of 1.9 m, and the main machine of the circular saw and the saw blade are moved during mining. The diameter of the saw blade used for mining circular saw blade is 1600 4200 mm, and it is usually used in groups of 2 or 3 pieces. If the cutting depth is 1.25 m, the combination of saw blades with diameters of 1.6m, 2.2m and 2.8m can be used; if the cutting depth is 1.9 m, the combination of saw blades with diameters of 2.2m, 3m and 4.2m can be used. The final width of the kerf is 15-20 mm. Photo of vertical sawing by double-blade mining circular saw with a diameter of 3.5m Flame rock cutter cutting method I. Cutting mechanism: Use the flame of the flame thrower to burn the rock to form a cutting surface to divide the rock. It can only be cut vertically. The loss of the cutting groove is large. In the case of three free surfaces, two surfaces are generally cut at most. It is better to cut only one surface, and the other two surfaces are separated by blasting or wedge method. Due to the difference of thermal expansion coefficients of different minerals in the rock, quartz changes from α-quartz to β-quartz at 573 ℃, and the volume of quartz decreases, resulting in disintegration. II. Applicable conditions: Vertical cutting of rocks with high quartz content, not horizontal cutting. The higher the quartz content is, the higher the cutting efficiency is; the lower the quartz content is, the lower the cutting efficiency is. III. Equipment composition: Air compressor, oil supply system, oxygen supply system, flame thrower Operation Drawing of Downward Trench Excavation by Flame Cutting Machine IV. Advantages and disadvantages: High efficiency (1.5 ~ 2.5 ㎡/H), flexibility, large cutting depth (up to 10 m), large cutting area, smooth cutting surface, not affected by season and climate. High noise (100 ~ 120 db), high dust, high fuel consumption, high cost (200 ~ 250 yuan/㎡) and high labor intensity, so it must be combined with other mining methods. Flame cutting machine combined with hand-held rock drill,dth button bits, drilling row holes combined with splitting mining method (referred to as burning rock drilling mining method) is the traditional, longest and most widely used granite mining method. Copyright notice If it involves copyright issues, please contact us to delete it! Return to Sohu to see more Responsible Editor:. wt-dthtools.com
, small mining area, hillside or sunken mining area with difficulty in highway development to transport blocks with small size, and small amount of waste rock and soil. The slope hoist is generally located outside the mining boundary. In the stope, the blocks need to be loaded on the trolley by other means of transportation. 3. Applicable conditions for joint development of fixed mast crane and truck transportation Mines with large stope height difference, small range, complex terrain, difficult road development, and less waste rock and dregs. The mast crane is usually located at the edge of the stope. The blocks outside the hoisting range shall be transported to the hoisting range of the mast crane by the traction winch or loader, and then lifted to the truck of the transport platform by the mast crane. 4. Development of aerial ropeway transportation The rope crane is used to complete the loading, lifting, transportation and loading operations at one time. Applicable conditions: stone mines with complex and steep terrain, large elevation difference, deep valleys, difficult highway development, large investment, small scale and small block size. 5. Applicable conditions for open chute transportation and development The terrain is complex, the elevation difference is large, the slope is steep (greater than 40º, and there is a shortage of capital construction funds. 6. Joint development [Mining process of stone deposit] The mining process is divided into seven processes: Stripping — Separation — Top turning — Segmentation — Shaping — Hoisting and transportation — Slag removal and waste discharge 1. Stripping 1. Basic concepts (1) Stripping range: all parts within the mining range that do not meet the processing and use requirements; (2) External stripping: the stripping of the surface and surrounding parts of the mineable ore body that do not meet the processing and use requirements before the mining of the deposit, so as to expose the mineable parts; (3) Internal stripping: the stripping of the part inside the ore body that cannot become blocks due to the existence of joints,DHD Drill bit, fissures and vein rocks. (4) Stripping ratio: refers to the ratio of the amount of earth and stone stripped to the volume of block mined. (5) Block rate: the ratio of the volume of blocks mined within a certain mining range to the volume of raw ore within the range is called the block rate. 2. Basic principle: simultaneous mining and stripping, stripping first 3. Requirements: The integrity and block formation of the ore body shall not be affected. Butterfly Green (XIII) II. Separation-the main process of stone mining 1. Concept: separate the strip-shaped block stone with a volume several times that of the block from the ore body. 2. Requirements: (1) Do not damage the ore body and ore-take protective measures (2) The specification size of the strip block stone shall be equal to the integral multiple of the specification size of the block plus the processing amount required for dividing the block. (3) According to the natural conditions of the ore body, make full use of natural fissures and bedding. (4) According to the technical performance of the mining equipment, give full play to the role of the equipment, improve efficiency and reduce costs. The width of the strip block stone is generally the height of the mining bench, and the length is a part of the mining bench. Three, top turn over-fall stone 1. Purpose: It is convenient to divide into blocks according to the required specifications. 2. Method: traction winch, loader, top stone machine, water pressure package and air pressure package. 3. Key points: use protective measures to prevent the stone from breaking when it is overturned. The kerf width of diamond saw mining is only 12 mm. When all the stones are separated from the ore body, it is very difficult to move or overturn the stones weighing hundreds of tons from the ore body directly through the 12 mm kerf. At present, domestic stone mines generally adopt the method of drilling a 25 × 25 × 50cm stone trough on the parent ore body and placing a hydraulic stone jacking machine to separate the stone from the displacement, which destroys the integrity of the ore body after the trough is drilled and affects the outturn rate of the ore body behind. New technology of air pressure pushing bag: The pneumatic pushing bag is inserted into the 12 mm saw kerf formed by the beaded wire sawing, and the compressed air is used to inflate the bag, so that the bag expands to generate dozens of tons of thrust, and the lever principle is used to push the stone to move or turn it over, so that the stone can be disintegrated in the subsequent process to produce blocks. The bag body is made of high-strength polymer rubber material and can be repeatedly stretched and used. Air pressure push bag (I) Air pressure push bag (II) Air pressure push bag (III) 4. Partition Dividing the strip block stones into rough blocks or blocks on the overturned strip block stones according to the specification of the required blocks. Quarry stone: a cuboid or cube with certain specifications and no cracks, which can meet the processing requirements of decorative plates. Rough block: the shape basically meets the specification requirements of the block, but the surface is uneven, with a positive error of more than 3,dth drill bits, and the block stone needs to be shaped. Metering block: the actual metered volume of the block after inspection. It is the actual effective volume of the block after deducting the excess volume caused by the size deviation. Methods: Chiseling, splitting, sawing, mechanical drilling and cutting, controlled blasting. Five, plastic surgery 1. Purpose: Trim the rough blocks into blocks that meet the requirements of specifications, so as to reduce the redundant workload in hoisting, transportation and processing and reduce the cost. For example, if the top surface of granite blocks is shaped and leveled by a fixed bead saw, the total error of the flatness is within 2cm, and the total error of the flatness only by manual leveling is up to 10 cm, and the time required for the saw blade of a sand saw to complete the "cut-in" stage is nearly doubled. 2. Method: wedging, splitting and sawing According to the shaping method, the blocks are divided into two categories: a. Saw face block (SS): All six sides are blocks shaped by the sawing method. b. Split face block (CS): Block with one or more sides shaped by chiseling 3. Shaping equipment: Large diameter circular saw, chain arm shaping machine, diamond band saw shaping machine, bead saw shaping VI. Hoisting and transportation 1. Mast crane (mast crane) Large lifting capacity, wide service range, strong adaptability, easy operation, high equipment price, large installation or displacement workload, slow lifting speed. The maximum lifting weight of 50 tons means that 18 cubic meters of block can be lifted. 2. Truck (wheeled) crane Need to install fixed feet, poor road adaptability, large tire loss, small lifting capacity, strong flexibility and versatility. 3. Crawler crane Can be directly hoisted, does not need to install fixed support legs, and has strong adaptability to roads, large lifting capacity and strong flexibility. Crawler crane 4. Front end loader: The multipurpose mining equipment can be used for shoveling, stripping, hoisting, hauling, cleaning working steps, prying stones and other operations. 5. Crawler excavator: As above, the front end is the loading device and the rear end is the digging device. 6. Gantry crane A crane of the bridge type in which a horizontal bridge is set on two legs to form a gantry. Gantry crane 7. Cable crane A bridge crane in which the trolley travels on a carrying rope. 8. Traction winch (1) Mine multi-purpose equipment can be used for: ① Traction power of slope winch ② Pull the blocks to the working range of the lifting equipment ③ Expanding joints and pouring stones ④ Power of lifting equipment (2) Operation mode: Various hauling operations can be completed by configuring different pulleys. VII. Slag removal and waste discharge Before the construction of stone mines, it is necessary to consider the construction of a dregs yard with sufficient capacity, which is a necessary preparation for continued production and safe production. Attention should be paid to the protection of resources, the protection of the environment, the comprehensive utilization and the improvement of efficiency. According to the requirements of the Technical Specification for Decorative Stone Open-pit Mines, Mining Drilling Equipment ,mining drill bit, the comprehensive recovery rate of decorative stone mines should not be less than 50%. [Classification of Mining Methods for Stone Mines] I. Mining method: Splitting, blasting, cutting, burning, etc. II. Selection basis of mining method: 1. Geological conditions of the deposit: joint occurrence, development degree, orebody shape … The thick orebody is favorable for mechanized mining, and the thin orebody is suitable for manual mining. Chisel hole splitting method should be used if the fissures and joints are developed and irregular 2. Rock type For example, basalt and gabbro without quartz can not be cut by flame, and the compressive strength of the rock is about 30 times of the tensile strength and 10 times of the shear strength. The splitting wedge is used to produce compressive tension on the rock to break the rock, which is especially suitable for deposits with developed horizontal joints and fissures. 3. Mine scale: 4. Specifications of blocks required: 5. Physical and geographical conditions: 6. Environmental protection requirements: 7. Technical and economic indicators: 8. Output, efficiency and benefit: Chisel split method I. Splitting mechanism and applicable conditions Mechanism: 1. The tensile strength of rock is relatively small. 2. The principle of "splitting" is applied to produce greater tension on the rock, and the rock breaks after being stressed. 3. When wedging, the action time of the force is short, the speed is fast, and the kinetic energy of the wedge is large. Applicable conditions: 1. It is applicable to rocks with nearly horizontal cracks. 2. The tensile strength of granite is less than that of marble, so it is more suitable for granite mining. 3. Rock is an anisotropic body with different tensile strengths in different directions, so the parameters of wedge holes are also different in different directions. 2. Artificial wedging and splitting method 1. Types and structures of tools-wedges A — Flat wedge; B — Pyramid wedge; C — Compound wedge 2. Operation method: hand-held rock drill For manual wedging and splitting of shallow holes and deep holes (rows of holes drilled on the splitting surface), the spacing between rows of holes is related to the splitting performance, and the minimum spacing is only 10-15 cm 3. Advantages and disadvantages: simple tool, simple method and low cost The labor intensity is high, the efficiency is low, the squareness of the block is poor, and the shaping workload is large. When mining granite, it is generally necessary to drill 10 meters of holes for each cubic meter of total ore and rock. According to the calculation of 30% of the block rate, it is necessary to drill 30-40 meters of holes for each cubic meter of finished block. Shallow borehole artificial splitting Disintegrating large granite material by artificial splitting method Shaping granite blocks by artificial splitting method Deep hole manual splitting mining disintegration separation body III. Splitting method of hydraulic splitting machine The principle is the same as that of manual splitting, which usually refers to the use of hydraulic splitters and deep-hole splitting for mining. Compared with the manual wedging method, the method ensures the consistency of hole arrangement and splitting, reduces the labor intensity and improves the efficiency. During operation, a drill hole for placing the hydraulic composite splitting wedge is drilled on a rock by a rock drill according to the presplitting direction, the hydraulic composite splitting wedge is placed in the hole, the splitting wedge and a hydraulic pump station are connected, high-pressure oil is transmitted to a hydraulic splitting head through an oil pipe, the hydraulic splitting wedge generates extrusion tension to two walls in the hole under the action of the high-pressure oil, and the rock is broken after being stressed. Borehole blasting method Applicable conditions: for all kinds of rocks with few natural fissures, separate large stones from rock mass by slight blasting Classification of methods: It can be roughly divided into ordinary blasting, conventional controlled blasting and grooved controlled blasting. Advantages: simple operation, high efficiency, strong applicability and low cost Disadvantages: poor squareness, low block rate, reduced stone strength, and many unsafe factors I. Ordinary blasting method 1. Agent: black powder 2. Blasting parameters: Hole diameter: 30 ~ 40 mm Hole spacing: horizontal hole spacing: 1 ~ 1.5m; Vertical pitch: 0.8 ~ 1.2m Hole depth: horizontal hole depth: 45 ~ 60% of separation block width Vertical hole depth: 60 ~ 80% of the height of the separation block Charge: 20 ~ 25% of hole depth Detonation: detonator or electric detonator Note: Measures to prevent excessive concentration of blasting force: Block charge and gun hole should not be packed too tightly II. Controlled blasting 1. Concept: Controlled blasting is a kind of precisely designed blasting with different explosives and ignition methods, which can not only achieve the desired effect, but also control the hazards caused by blasting within the specified allowable range. This kind of blasting with dual control of blasting effect and blasting hazards is called controlled blasting. 2. Agent: Black powder, detonating cord, No.2 rock explosive, blasting tube, metal incendiary agent, static expansion agent (1) Detonating cord: It takes the single substance high explosive RDX or TEK as the core, and its external image is the fuse, slightly thin, and the color is mostly red. The explosive charge of the detonating cord in China is 12 ~ 14 G/m, and the detonation velocity is 6500 ~ 6800 m/s. It can be detonated by fire detonator or electric detonator, and the hole spacing is 20 ~ 40. The internal drilling medium for placing the detonating cord can be air or water. Mining site by detonating cord controlled blasting (2) Metal incendiary agent (high-energy incendiary agent): The metal oxidant reacts with the metal reducing agent to generate high-temperature expansion gas, and the rock is cracked under the combined action of the expansion pressure and the thermal effect. Such as: 2Al + 3MnO2 = Al2O3 + 3Mn + 221 kcal (or + 9.52 × 105 J) Commonly used oxidants: MnO2, CuO, Fe3O3 … Commonly used reducing agents: Al, Mg, Fe + Mg … (3) Static expansion agent: Calcium oxide, inorganic salt and organic additives, and the tension generated by the volume expansion of the reaction after adding water. Such as: CaO + H2O-Ca (OH) 2 + 15.5 kcal, with volume expansion of 3 times, the expansion stress is about 30 ~ 50Mpa (the tensile strength of rock is about 5 ~ 12MPa). Mechanical cutting method Concept: Separation of rock blocks or blocks directly from the rock mass with the aid of mechanical equipment in accordance with the required block specification The invention has the advantages of no damage to the ore body and the block, flat cutting surface, no need of shaping, high block rate, large block size, low labor intensity and high production efficiency. Advanced technology, technology and equipment. Common equipment: rock drill, steel cable stone sawing machine, diamond wire saw, chain saw, disc saw. 1. Steel cable stone sawing machine sawing method It appeared at the end of the 19th century and was used for marble mining with quartz sand as raw material. It was discontinued at the end of the 20th century. II. Diamond wire saw cutting method 1. Equipment composition: (1) Driving device (2) Diamond rope (3) Working column and guide wheel The steel wire rope is sealed by spring, injection molding, rubber injection, etc. Fixed diamond bead 2. Working methods: (1) Ring traction cutting method When the ore body has two or more free surfaces, a horizontal hole and a vertical hole are drilled along the designed sawing surface, so that the two holes are connected and on the same cutting surface. (2) Rope pressing and cutting method When the number of the free surfaces of the ore body is less than two, a hole is drilled on the working face of the bench, a rope pressing wheel is arranged on a multi-purpose drilling machine or a cutting upright post and is placed in the hole, and a carborundum rope bypasses the rope pressing wheel and forms a closed loop with a driving wheel of a sawing machine to work. Diamond wire saw traction cutting Diamond wire saw traction cutting 3. Applicable conditions of diamond wire saw It can be used for full sawing and mining of marble and granite or combined mining with other equipment; it can also be used for stone processing and block shaping. 4. Advantages and disadvantages The mining cost is high, but the sawing surface is flat, the sawing area is large, and the block rate is high 4. Sawing method of arm-type stone sawing machine According to the cutting tool, it is divided into: 1) fixedly instal a hard alloy or diamond segment cutting edge on a cutting arm transmission chain to form a hard alloy cut chain or a diamond cutting chain; 2) Polyurethane injection molded cutting tape with diamond cutting segments. The main body of the diamond cutting belt is a rectangular diamond segment threaded on six side-by-side stainless steel wire ropes for aviation, and the segments are all sealed by special polyurethane injection molding. BENETTI, Italy JB-990 mining band saw vertical cutting operation The vertical and horizontal cutting of the ore body can be carried out, and the vertical and horizontal cutting positions can be quickly and flexibly switched at the same installation position. It is suitable for the mining of soft stones such as marble, limestone and travertine with medium hardness. At present, the maximum vertical cutting depth of large chain arm saw can reach 8 meters, the longest horizontal cutting depth can reach 4.8 meters, and the chain width is generally 33.5 mm. The maximum cutting depth of the mining band saw can reach 4.8 meters, and the width of the saw gap is generally 38 mm. At present, the maximum vertical cutting depth of the arm saw has reached 8 m, and the mining bench with a height of 8 m can be mined. 5. Disc stone sawing machine sawing method A saw blade with a diameter of 4.2 m can be mined to a height of 1.9 m, and the main machine of the circular saw and the saw blade are moved during mining. The diameter of the saw blade used for mining circular saw blade is 1600 4200 mm, and it is usually used in groups of 2 or 3 pieces. If the cutting depth is 1.25 m, the combination of saw blades with diameters of 1.6m, 2.2m and 2.8m can be used; if the cutting depth is 1.9 m, the combination of saw blades with diameters of 2.2m, 3m and 4.2m can be used. The final width of the kerf is 15-20 mm. Photo of vertical sawing by double-blade mining circular saw with a diameter of 3.5m Flame rock cutter cutting method I. Cutting mechanism: Use the flame of the flame thrower to burn the rock to form a cutting surface to divide the rock. It can only be cut vertically. The loss of the cutting groove is large. In the case of three free surfaces, two surfaces are generally cut at most. It is better to cut only one surface, and the other two surfaces are separated by blasting or wedge method. Due to the difference of thermal expansion coefficients of different minerals in the rock, quartz changes from α-quartz to β-quartz at 573 ℃, and the volume of quartz decreases, resulting in disintegration. II. Applicable conditions: Vertical cutting of rocks with high quartz content, not horizontal cutting. The higher the quartz content is, the higher the cutting efficiency is; the lower the quartz content is, the lower the cutting efficiency is. III. Equipment composition: Air compressor, oil supply system, oxygen supply system, flame thrower Operation Drawing of Downward Trench Excavation by Flame Cutting Machine IV. Advantages and disadvantages: High efficiency (1.5 ~ 2.5 ㎡/H), flexibility, large cutting depth (up to 10 m), large cutting area, smooth cutting surface, not affected by season and climate. High noise (100 ~ 120 db), high dust, high fuel consumption, high cost (200 ~ 250 yuan/㎡) and high labor intensity, so it must be combined with other mining methods. Flame cutting machine combined with hand-held rock drill,dth button bits, drilling row holes combined with splitting mining method (referred to as burning rock drilling mining method) is the traditional, longest and most widely used granite mining method. Copyright notice If it involves copyright issues, please contact us to delete it! Return to Sohu to see more Responsible Editor:. wt-dthtools.com
09:41
Status of Waste Oil
Original Title: Status of Waste Oil Regeneration and Brief Introduction of Its Process Technology Total Cumulative Title 1350 The status of waste oil regeneration and brief introduction of its technology Source: Guangdong Chemical Authors: Yu Yanyan, Yang Xin, Wang Jie Waste oil is a dihedron, which has the dual characteristics of pollution and resource: improper treatment will cause environmental pollution, and recovery and recycling will save energy and alleviate the pressure of resource shortage. According to the provisions of the National List of Hazardous Wastes, waste mineral oil belongs to hazardous waste, numbered HW08. On February 4, 2017, the 2016 edition of the Guidance Catalogue of Key Products and Services for Strategic Emerging Industries, compiled by the National Development and Reform Commission, was officially released, in which the recycling of waste mineral oil was listed in the Guidance Catalogue of Key Products and Services for National Strategic Emerging Industries. However, by 2017, there were 523 enterprises with waste oil recycling and treatment qualification in China, and only 1/3 of the waste oil was treated by these compliant enterprises. A considerable part of the waste mineral oil was basically treated by non-qualified enterprises, and some of them were not properly disposed of, but were often treated by negative means such as disorderly disposal, arbitrary disposal, burning and burying. However, in China, the research on the regeneration process of waste oil was carried out relatively late, and the related investment was relatively small. Only some special petroleum industries could use advanced technology, while most of them were refineries in the form of small workshops, with backward technology, resulting in very low value of finished products. The low price has further limited the development of the industry, and the process has not been improved. In foreign countries, many advanced technologies and processes are becoming mature and have reached the stage of industrial production, such as acid-free process, distillation-hydrogenation and other processes are becoming the mainstream of waste oil treatment in Western countries. However, due to the advancement of these technologies, the complexity of operation, the large one-time investment of regeneration equipment and the need for high-level skilled workers, it is difficult to implement a large number of these technologies in China at this stage, so finding a better solution has become the key to waste oil treatment in China. 1. Current status of waste oil recycling In foreign countries, the regeneration of waste oil started earlier. In the 1960s, some developed countries in Europe and the United States began to study it, and since then they have accumulated valuable experience. Until now, the western countries are in the leading position in the waste oil recycling industry and even in the whole oil industry. The reasons for their success are related to the improvement of policies and government subsidies. It can be seen that relevant government policies, industry standards and market cooperation are prerequisites for achieving a virtuous circle of waste oil regeneration. The 2013-2017 China Waste Oil Market Supply and Demand Analysis and Investment Prospect Research Report released by Booz Data shows that although China's waste oil products have always existed, there has been no effective progress in the effective utilization of waste oil. China's waste oil market is large and will grow with the increase of market demand. However, in China, the reasonable recovery rate of waste oil is not high, which is mainly affected by the relevant policies and regulations of national and local industries, upstream waste oil recovery links, downstream regeneration technology and other restrictions. Expand the full text Although the state and the oil industry have been promoting the formulation and implementation of policies, from the current point of view, although policies and regulations have guiding significance, they are not enforced, there are no severe penalties and certain financial incentives, resulting in many difficulties in operation. Due to the vast land area, the investment and understanding of waste oil recovery and regeneration vary from place to place, and the implementation is different, which leads to many difficulties in the recovery process of waste oil regeneration industry. Except for the special field of petroleum, the recovery of other industries is quite difficult, mainly including the following problems: (1) Unclassified recovery, mixed oil varieties are complex, and the performance indicators of waste oil are different. Different types and proportions of waste oil are mixed together, which makes the subsequent regeneration treatment more difficult; (2) Transportation is restricted. The composition of waste oil is complex, containing different pollutants and impurities that may lead to corrosion and scaling of storage tanks, so the transportation equipment should be anticorrosive and explosion-proof at the same time. However, at present, the waste oil recovery mechanism seldom has such special equipment; (3) Disposal of violations. For example, in the automobile repair industry, because there is no qualified unit nearby to deal with the hazardous wastes produced by the automobile repair industry, the compliance unit is far away and the transportation distance is long, resulting in high transportation and disposal costs, so the waste oil is transferred to other oil companies for disposal without going through the transfer formalities, or even sold to waste collectors at will. 2. Domestic and foreign regeneration process Due to the increasing necessity of environmental protection and increasingly stringent environmental legislation, the treatment and recycling of used oil has become very important. Waste oil recycling technology has changed significantly over the past decade. In foreign countries, the regeneration of waste oil is mainly based on hydrogenation refining process, as well as new supercritical technology, membrane separation technology, molecular distillation technology, etc., while in China, it is mainly based on small-scale acid-base refining and adsorption refining. The recovery of used oil can be accomplished by the following different methods: re-cleaning, re-refining, and re-refining. The regeneration and recovery products of used oil are lubricating oil and fuel oil with low quality requirements, respectively, while the re-refining of used oil is to produce base oil with the same quality as crude oil. In general, waste oil refining goes through the following four steps: dehydration and degreasing, deasphalting, fractionation, and finishing. 2.1 Sulfuric acid-clay refining process Sulfuric acid-clay refining process is the first technology to be used in the research of waste oil regeneration process at home and abroad, in which a large amount of sulfuric acid and clay are used to treat waste oil. The used oil is pretreated (pre-flash or vacuum distillation) to separate water and light hydrocarbons. Concentrated sulfuric acid (10% -15%) is added to the dewatered used oil, where foreign matter (impurities such as resins, asphaltenes, oxidation products, etc.) Will form a sludge that will allow it to settle within 16-48 hours and then be separated from the used oil. The filtered oil is distilled to produce a base oil of a fuel oil having various characteristics. Sulfuric acid refining is mainly a chemical reaction, including sulfonation, esterification, polymerization, condensation and neutralization. In addition, there are flocculation by physical and chemical action and dissolution by physical action. Sulfuric acid can react with the non-ideal components present in the waste oil, has a strong ability to remove non-hydrocarbons, and can also remove olefins quite thoroughly. However, the regenerated oil sample treated by sulfuric acid can not achieve the expected effect in terms of quality, use effect and value, so the oil sample treated by sulfuric acid needs to be refined by a large amount of clay, so that the color of the regenerated oil is clearer, and the properties such as stability and viscosity are closer to those of normal diesel oil, and finally the expected qualified oil is obtained. However, in the refining process, this method will produce a lot of acid gases such as sulfur dioxide, which are harmful to human body and pollute the environment, solid wastes such as acid sludge, and liquid harmful substances such as acid water, which are difficult to deal with. In addition, the subsequent clay refining process will still pollute the environment and produce oily saturated clay which is difficult to treat. Under the increasing environmental pressure and the concept that the rapid economic development required by the current modern economic system is gradually turning to economically friendly development and green development, this technology has been banned in most countries, including many developing countries, thin film distillation ,thin film distillation, and it is only a matter of time before the sulfuric acid-clay process is eliminated by the times. 2.2 Solvent extraction refining process Solvent refining process is still one of the mainstream methods to produce diesel oil in industry. The principle of solvent refining is to remove the additives, oxidation products, sludge and other impurities in the waste lubricating oil under certain conditions by using the different solubility of some organic solvents to the hydrocarbons, additives, oxidation products, sludge and other impurities contained in the waste lubricating oil, and then distill and recover the solvent to obtain crude products, which are refined by clay to become reclaimed oil. In foreign countries, solvent refining has gradually changed from propane to N-methyl pyrrolidone and furfural as the solvent of the refining process, among which N-methyl pyrrolidone is widely used because it has the lowest toxicity and can be used at a lower solvent-to-oil ratio, thus saving energy. In China, the mixture of alcohol and ketone (isopropanol, acetone, etc.) [8-10] is mainly studied as a solvent for refining, which can reduce the coking and scaling problems in the subsequent solvent recovery distillation process. Although the solvent refinement process has the above advantages, there are still some problems that can not be solved. The disadvantage of solvent refining technology is the dependence of the quality of the finished product on the quality of the feedstock, because the process is a physical process and does not involve any chemical reactions. At the same time, the ratio of solvent to oil remains high in the refining process, and the extensive use of this toxic solvent will cause serious harm to the environment and equipment. The unstable price fluctuation and high unit price of the promising N-methylpyrrolidone solvent are also one of the reasons that restrict the development of this process. Although the solvent can be recovered and reused, it is difficult to recover, the cost of recovery is high, and the yield of recovered oil is not ideal. Nowadays, people at home and abroad have begun to study how to improve the solvent refining process, in which most of them will involve the addition and use of additives. The simple understanding of additive technology is to add a certain amount of suitable additive in the solvent refining process in order to solve various problems that often occur in the solvent refining process, so as to obtain better refining effect [10]. However, most of the current research on the technology of additives is still limited to the preliminary research in the laboratory, and it is difficult to achieve in the scale-up experiment and industrial use, so the technology of additives still has great research value. 2.3 Hydrogenation regeneration process Hydrorefining reactions aimed at removing foreign elements, hydrogenating olefins and aromatics, and hydroconversion reactions aimed at changing the structure of hydrocarbons through cracking and isomerization. The hydrotreating catalyst consists of an active phase made of molybdenum or tungsten sulphide and cobalt or nickel on an oxidic support. The oil and hydrogen are preheated and the oil is trickled down through a reactor packed with catalyst particles where the hydrogenation takes place. The oil product is separated from the gas phase and then stripped to remove traces of dissolved gases or water. Because hydrofining can reduce the loss of effective substances in oil samples, improve the yield of regenerated waste oil, and will not produce a large number of waste clay and pollute the environment as clay refining process, so hydrofinishing process has gradually replaced clay refining as the last step in the reprocessing process, occupying the main position in the research of waste oil regeneration. Almost all foreign countries adopt the hydrofining process to regenerate the waste oil. Compared with other technologies, the hydrofining process has the following disadvantages: high pressure and high temperature; need for hydrogen supply facilities; high safety standards; high operating costs and capital costs; low operating efficiency; crude oil analysis and pretreatment; catalyst regeneration. In this case, the application of the technology of the pressurization process requires relatively high investment, the hydrogenation process has higher requirements for equipment, and the operating conditions are more stringent, so the unit cost of regenerated oil production is higher. For China, which is still in the ranks of developing countries, there are still many difficulties in promoting the hydrofinishing process in an all-round way. 2.4 Thin film evaporation technology Evaporation that accelerates the evaporation process by forming a thin film of the liquid is called thin-film evaporation. The principle that thin film evaporation can accelerate evaporation is that liquid forms a thin film under reduced pressure. The film has a large vaporization surface area, the heat transfer is fast and uniform, there is no influence of liquid co-pressure, and the material can be better prevented from overheating. In a thin film evaporator for waste oil treatment, the feed is distilled into two parts by a cyclone column, and the light hydrocarbons are easily and rapidly distilled due to the formation of a tangential flow film. The vaporized lighter fraction, consisting of light hydrocarbons (gas, diesel) and water, condenses in the upper part of the chamber, from which it separates. The heavier oil portion of the bottom cycle is heated, reducing heat transfer within the chamber and reducing coke formation. Chemically pretreat the used oil to avoid the precipitation of contaminants that could lead to corrosion and contamination of the equipment. The pretreatment step was carried out at a temperature of 80 to 170 ° C. The chemical treating compound includes sodium hydroxide added in an amount sufficient to achieve a pH of about 6.5 or higher. The pretreated used oil is first distilled to separate water and light hydrocarbons. The water is treated and sent to a wastewater treatment facility, where the light hydrocarbons are used as fuel or sold as a product. Thereafter, the anhydrous oil is distilled in a thin film evaporator under high vacuum to separate diesel fuel, which can be used at the plant or sold as fuel. Heavy materials such as residues, metals, additive degradation products, etc. Are transferred to the heavy asphalt stream. The Vaxon and EcoHuile (Sotulub) processes are based on the vacuum distillation of oil fractions in a thin film evaporator, which reduces coking caused by cracking of hydrocarbons and oil impurities at high temperatures. Both processes pretreat the alkaline waste oil, which requires the elimination of synthetic and vegetable oils from the feedstock. The Vaxon process has additional solvent extraction processing equipment to produce a higher quality product oil than the Ecohuile product. Despite this, the product quality is worse than the solvent extraction process described above. To produce high quality base oils, thin film evaporation technology needs to be combined with other technologies to add post-treatment steps, but these modifications will increase operating and capital costs, making it economically less attractive. 2.5 Membrane treatment The basic principle of membrane separation technology is that under the action of an external driving force, various substances with different properties in the raw material liquid can selectively pass through the membrane, so as to effectively separate substances with different components and purify certain substances. Membrane separation technology is a new separation technology with high efficiency and energy saving. Its main advantages are green environmental protection, high separation efficiency, simple operation, high safety and easy industrial use. On the other hand, the application of membrane separation technology can also improve the regeneration rate of waste oil, reduce unnecessary loss of raw materials, and reduce the amount of clay used in the subsequent clay supplementary refining process. It not only reduces the production of solid waste residue, but also makes the economic accounting of the process more reasonable, and provides a basis for large-scale industrial production. Mynin et al. Used inorganic membranes based on graphite and ceramics to regenerate waste industrial lubricating oil, transformer lubricating oil, engine oil, etc. The results show that the quality of industrial lubricating oil and transformer lubricating oil can meet the requirements of reuse after inorganic ceramic membrane filtration, and the physical and chemical properties of engine oil can also be improved to a certain extent. Yuhe Cao et al. Used three kinds of hollow fiber polymeric membranes (PES, PVDF, PAN) to treat the regenerated waste lubricating oil, which not only effectively removed metal particles and dust, but also greatly improved the viscosity and flash point of the regenerated oil. At present, membrane separation technology has been widely used, domestic and foreign experts and scholars have done a lot of research on the treatment of oily wastewater by membrane technology, and have achieved good results, but it is difficult to be applied in the regeneration of waste oil in practice. Because of the complex composition, high impurity content and high viscosity of waste lubricating oil, there are two problems in membrane separation and regeneration of waste lubricating oil, namely, small membrane permeation flux and serious membrane pollution. Concentration polarization and membrane fouling can significantly reduce the permeation flux and shorten the service life of the membrane, which are the main factors restricting the application and development of the membrane process. 3. Conclusion The state has begun to pay attention to the progress of waste oil recycling industry, which is a cause beneficial to the country and the people, and vigorously develop waste oil recycling from the perspective of saving petroleum resources and environmental protection. The sources of waste oil in our country are scattered, the varieties are many and the waste oil is not classified and recycled, the phenomenon of illegal disposal is everywhere, and the supply of raw materials for recycling enterprises is very difficult. Therefore, it is difficult to establish large-scale centralized treatment plants, and only small and medium-sized intermittent production methods can be adopted. Because of this, some foreign advanced technologies are not suitable for use in our country. If these small and medium-sized enterprises want to succeed, they must control the production and recovery of waste oil from the upstream, establish a waste oil recovery system, provide sufficient raw materials for the follow-up regeneration treatment, and then eliminate backward technology and use acid-free technology in line with international standards. Sulfuric acid-clay treatment was the first petroleum regeneration process to be used, but it has been gradually replaced by new technologies such as solvent extraction and hydrotreating. Most of the current solvent extraction technologies use propane and isopropanol as solvents, but it has a low selectivity for non-ideal components and requires a high solvent-to-oil ratio, which increases energy consumption. Hydrofining can reduce the loss of effective substances in oil samples, improve the yield of regenerated waste oil, and will not produce a large number of waste clay and pollute the environment as in the clay refining process, so the hydrofinishing process has gradually replaced the clay refining, but because hydrofining requires excessive capital investment and operational constraints, So that it can no longer be widely used in small and medium-sized enterprises. Thin-film evaporation technology requires the addition of post-treatment steps and the combination with other technologies, but these modifications will increase operating and capital costs, making it less economically attractive. Most of the processes use a combination of different technologies, such as solvent extraction and hydrofining, thin film evaporation and different refining processes and hydrotreating. However,wiped film distillation, from the analysis of the current situation of domestic waste oil regeneration, the most attractive method for re-refining waste oil can be the combination of solvent extraction and membrane separation, and more research efforts should be made to explore the best solvent and solve the problems arising from membrane treatment. Return to Sohu to see more Responsible Editor:. toptiontech.com
Original Title: Information | Will Oil Prices "Fall"? Jingtai Capital After a new round of refined oil price adjustment, domestic No.92 gasoline has entered the "9 yuan era" in an all-round way, while No.95 gasoline in some areas has officially entered the "10 yuan era", and even in a few areas, No.95 gasoline has broken through 11 yuan/liter. For example, after the price adjustment in Hainan, the highest retail price of No.92 gasoline is 10.43 yuan/liter, and that of No.95 is 11.1 yuan/liter. The next round of oil price adjustment is at 24:00 on June 28. International oil price news International oil prices fell on the 15th. By the end of the day, light crude oil futures for July delivery on the New York Mercantile Exchange fell $3.62, or 3.04%,wiped film distillation, to $115.31 a barrel, while London Brent crude oil futures for August delivery fell $2.66, or 2.20%, to $118.51 a barrel. Expand the full text | The impact of oil price of 10 yuan If calculated according to the 50L family car fuel tank,jacketed glass reactor, this price increase will cost about 12 yuan more to fill up, which seems not much, but compared with the beginning of the year, the oil price will rise by two yuan, an increase of 25%, and it will cost 100 yuan more to fill up the 50L fuel tank. Increase the travel cost of every family with a car by 25%. According to the data released by the Traffic Management Bureau of the Ministry of Public Security, China has 302 million cars (all calculated according to 50 L fuel tanks), 50l rotovap ,cbd crystallization equipment, which will cost at least 3.6 billion yuan more to fill up. In fact, this data is larger, which is a real increase in social costs. The important thing is that most of the transport vehicles in our country are fuel vehicles at present, and the rise in gasoline prices will lead to the rise in transport prices. This part of the rising price will also appear in our daily life. Even if you don't drive, the rising price of gasoline will still affect you. In addition, crude oil not only has the function of producing gasoline, but also can produce heavy oil and aviation kerosene. Large cargo ships and aircraft are big oil consumers. With the rising price of crude oil, the use cost of these people will also rise, which will eventually be superimposed on our daily life. Moreover, crude oil is also an important chemical raw material, and the rising price of crude oil will lead to the rising price of plastics, asphalt and other products. The international oil price has dropped by 6.83%, and the next oil price adjustment is expected to fall. International oil prices have fallen by more than 5.5%. At present, Brent crude oil prices have fallen to the range of $113 per barrel, and US crude oil has also fallen to around $109 per barrel, which makes the next oil price adjustment very hopeful to usher in a decline. As of June 18, light crude oil futures for July delivery on the New York Mercantile Exchange fell $8.03, or 6.83%, to close at $109.56 a barrel, while London Brent crude oil futures for August delivery fell $6.69, or 5.58%, to close at $113.12 a barrel. Next Monday, the negative operation of domestic crude oil change rate will continue to widen. According to the national refined oil mechanism, the price adjustment amount is less than 50 yuan and will not be adjusted. It is hoped that this round of price adjustment will exceed the red line of price adjustment. It has been too long and has not been reduced once. It is not difficult to see that long-distance transport trucks are under greater pressure! This round of domestic refined oil price adjustment will start at 24:00 on June 28, 2022. END The article is the information point collated by Jingtai and does not constitute investment advice. Please read it carefully and return to Sohu to see more. Responsible Editor: (function() { function getBrandHtml() { var brands = [],cbd centrifugal extractor, html = ''; for(var i = 0; i < brands.length; i++) { var brand = brands[i]; if(brands.length i+1) { html+= ''+brand.name+''; } else { html+= ''+brand.name+'、'; } } return html; }; if(document.getElementById('linkBtn')){ document.getElementById('linkBtn').onclick = function() { $('#brands').removeClass('brand');$ ( '# tipInfo').text ( 'Real name responded'); $ ('#linkBtn').remove();$ ('.real-response .content').css('line-height', '20px');$ ('.real-response .time').css('line-height', '20px'); }; document.getElementById('brands').innerHTML = getBrandHtml(); }; })();。 toptiontech.com
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Working principle of
Original Title: Working Principle of Wiped Film Molecular Distillation Unit AYAN-B60 molecular distillation is a special liquid-liquid separation technology. It is different from the traditional distillation which relies on the separation principle of boiling point difference,rotary vacuum evaporator, but relies on the difference of mean free path of molecular motion of different substances to achieve separation. When the liquid mixture flows along the heating plate and is heated,nutsche filter dryer, the light and heavy molecules will escape from the liquid surface and enter the gas phase. Because the free paths of the light and heavy molecules are different, the moving distances of the molecules of different substances after escaping from the liquid surface are different. If a condensing plate is properly arranged, wiped film evaporator ,wiped film evaporator, the light molecules will be condensed and discharged when they reach the condensing plate, while the heavy molecules will be discharged along the mixed liquid when they do not reach the condensing plate. In this way, the purpose of material separation is achieved. The pressure difference between the boiling film and the condensation surface is the driving force for the flow of the vapor, which is caused by a small pressure drop. Operating at 1 mbar requires a very short distance between the boiling surface and the condensing surface, and distillers based on this principle are called short-path distillers. The short-path distiller (molecular distillation) has an internal condenser on the opposite side of the heating surface and reduces the operating pressure to 0.001 mbar. Short-path distiller is a thermal separation process working under the pressure of 1 ~ 0.001 mbar. Its low boiling temperature is very suitable for heat-sensitive and high-boiling substances. It consists of a cylindrical cylinder with a heating jacket, a rotor and a built-in condenser, and a film scraper and an anti-splashing device are precisely installed on the fixing frame of the rotor. The built-in condenser is located in the center of the evaporator,jacketed glass reactor, and the rotor rotates between the cylindrical cylinder and the condenser. The short-path distiller consists of an externally heated vertical cylinder, a condenser located at its center, and a film scraper rotating between the distiller and the condenser. Return to Sohu to see more Responsible Editor:. toptiontech.com