Efficient and environment-friendly machine-made refined sand production system

Abstract

The utility model relates to an efficient and environment-friendly machine-made fine sand production system which comprises a bar type feeder, a screen feed opening of the bar type feeder is connected to a linear vibrating screen I, and a screen feed opening of the bar type feeder is connected to a jaw crusher; a feed opening of the jaw crusher and an oversize feed opening of the linear vibrating screen I are connected to the intermediate crushing cone crusher, and a feed opening of the intermediate crushing cone crusher is connected to the linear vibrating screen II; screen discharge ports of the linear vibrating screen I and the linear vibrating screen II are connected to a trough type sand washer, a clean sand outlet of the trough type sand washer is connected to a rod mill, and a discharge port of the rod mill is connected to a high-frequency dewatering screen. A slurry outlet of the groove type sand washer and a slurry opening of the high-frequency dewatering screen are sequentially connected to a high-efficiency thickener and a plate-and-frame filter press. The dry-wet combined sand making process system is high in sand forming rate, quality indexes such as mud content, water content, grading and stone powder content of finished product sand can be well controlled in the sand making process, and the quality of finished product machine-made fine sand is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to solid waste resource comprehensive utilization technical field, concretely relates to a kind of efficient environmental protection's mechanism fine sand production system. BACKGROUND

[0002] Sand aggregate, as the main component of building materials such as concrete and paving stone, accounts for 60% to 75% of the volume, and is the largest and indispensable raw material for infrastructure, which can be widely used as metallurgical, underground filling material, highway asphalt, cement, water and electricity concrete and general building concrete aggregate building materials.

[0003] Sand aggregate is mainly divided into natural sand and artificial sand according to the source, but with the continuous exploitation and utilization of natural sand, the natural sand resources are rapidly decreasing, and some areas are almost exhausted. Excessive development makes the river sand less and less, causing irreparable damage to river ecology, flood control and channel safety. Artificial mechanism sand is a rock particle processed by mechanical crushing and screening of inert stone materials such as rock, pebble and waste rock from mine, which is an effective substitute for natural sand.

[0004] The current commonly used artificial mechanism sand production process mainly includes dry method and wet method. The characteristics and disadvantages of the two processes are as follows:

[0005] Dry sand making process refers to that, except for the spray dust removal process, the whole sand making production line basically does not use water, which is suitable for the matching use of fine crushing and building sand shaping system. This process requires high content of impurities such as soil and organic matter in raw materials, and the content of impurities such as soil in mother rock needs to be strictly controlled, otherwise it is easy to cause production system blockage and overload operation of dust collection system, product aggregate stone powder content exceeds the standard, fine aggregate fineness modulus is high, dust pollution is serious and other problems.

[0006] Wet sand making process involves sand and gravel production in all aspects with water as working medium and dust suppression medium, which can remove organic matter and other soluble impurities on the surface of sand and gravel, and the finished product has good appearance and high cleanliness, produces less dust during production, and requires lower investment in dust collection facilities than dry process, which is more friendly to the ecological environment. However, wet process will cause stone powder particles to be lost in the washed mud, and the finished product sand almost does not contain stone powder, the fine aggregate does not meet the requirement of 2.4 to 2.8 of artificial sand fineness modulus in Water Conservancy Concrete Construction Specification, direct use will increase the cement content of concrete, and the mud containing a large amount of stone powder must be treated before being discharged, which will inevitably increase the investment in sewage treatment; In addition, the moisture content of finished product sand is high, which does not meet the requirement of less than 6% of Water Conservancy Concrete Construction Specification. UTILITY MODEL CONTENTS

[0007] In view of the above problems, the utility model provides a kind of efficient environmental protection's mechanism fine sand production method, production system and application, to overcome the existing sand production process product sand gradation unreasonable, sand forming rate is low, production is accompanied by dust pollution or drainage pollution and many other problems with dry-wet combined sand making process system, optimize product quality, improve production efficiency, avoid secondary pollution.

[0008] Specific technical solutions are:

[0009] The utility model provides a kind of efficient environmental protection's mechanism fine sand production method, including the following steps:

[0010] (1) feed screening: using high pressure rinse water to wet ore and make sludge dispersed, and the material is screened by bar feeder, and +60mm screen material and-60mm screen material are obtained;

[0011] (2) one-stage screen washing: using high pressure rinse water to one-stage screen washing-60mm screen material, make sludge further dispersed, while separating sludge and block, and +20mm screen material I and-20mm screen material I are obtained;

[0012] (3) coarse crushing, medium crushing and screening: +60mm screen material is coarsely crushed, and coarse crushing product is combined with one-stage screen washing +20mm screen material I to medium crush; after medium crushing, high pressure rinse water is used to screen washing medium crushing product, and +20mm screen material II and-20mm screen material II are obtained;

[0013] (4) two-stage sand washing: one-stage screen washing-20mm screen material I and medium crushing-20mm screen material II are combined to carry out two-stage sand washing operation, and slurry and clean sand are separated;

[0014] (5) fine crushing closed circuit screening: +20mm screen material II is finely crushed, and the fine crushing product is screened again, and +15mm screen material and-15mm screen material are obtained; +15mm screen material is returned to fine crushing equipment to be finely crushed and screened until all materials are finely crushed to-15mm qualified product;

[0015] (6) wet type rod mill sand making and dehydration: clean sand obtained by two-stage sand washing and part-15mm screen material obtained by fine crushing are combined to carry out wet type rod mill sand making operation, and after dehydration, rod mill product is 0.2~2.5mm finished product washed sand;

[0016] (7) crushing, shaping and grading: part-15mm screen material obtained by fine crushing is crushed and grain type is modified, and then screened by double-layer screen, and 10~15mm finished product coarse aggregate is obtained as upper layer screen product, 4.75~10mm finished product medium coarse aggregate is obtained as lower layer screen product, and 0~4.75mm mechanism fine sand is obtained as lower layer screen product;

[0017] (8) slurry dewatering: the slurry obtained from the two-stage sand washing and the slurry dewatered from the rod mill product is treated by concentration and pressure filtration to obtain fine slurry and overflow water, and the overflow water can be recycled after being clarified by sedimentation.

[0018] Further, the high-pressure flushing water in steps (1)-(3) is all water with a water pressure of 0.3-0.5 MPa.

[0019] The utility model discloses further provided a kind of efficient and environment-friendly mechanism fine sand production method's equipment system of above-mentioned, including bar strip feeder, the bar strip feeder screen under discharge port is connected to linear vibrating screen I, the bar strip feeder screen upper discharge port is connected to jaw crusher;The jaw crusher under discharge port and the linear vibrating screen I screen upper discharge port are connected to medium crushing cone crusher, the medium crushing cone crusher under discharge port is connected to linear vibrating screen II;

[0020] The linear vibrating screen I and the linear vibrating screen II screen under discharge port are all connected to tank sand washer, the tank sand washer clean sand outlet is connected to rod mill, and the rod mill discharge port is connected to high-frequency dewatering screen;The tank sand washer slurry outlet and the high-frequency dewatering screen slurry outlet are sequentially connected to efficient thickener, plate-and-frame filter press;

[0021] The linear vibrating screen II screen upper discharge port is connected to fine crushing cone crusher, and the fine crushing cone crusher discharge port is connected to heavy circular vibrating screen, and the heavy circular vibrating screen screen upper discharge port is connected to fine crushing cone crusher feed inlet, and the heavy circular vibrating screen screen under discharge port is connected to rod mill and vertical shaft impact crusher, and the vertical shaft impact crusher discharge port is connected to double-layer linear screen.

[0022] Further, the jaw crusher under discharge port and medium crushing cone crusher feed inlet, linear vibrating screen screen upper discharge port and medium crushing cone crusher feed inlet, heavy circular vibrating screen screen upper discharge port and fine crushing cone crusher feed inlet are all connected by belt conveyor and buffer ore bin.

[0023] Further, the linear vibrating screen II under discharge port and tank sand washer feed inlet, rod mill discharge port and high-frequency dewatering screen feed inlet are all connected by ore slurry pool and residue slurry pump.

[0024] Further, heavy circular vibrating screen screen under discharge port and rod mill are further provided with distribution bin, and heavy circular vibrating screen screen under discharge port and distribution bin feed inlet, distribution bin discharge port and rod mill feed inlet are all connected by belt conveyor, and distribution bin discharge port and vertical shaft impact crusher feed inlet are further provided with buffer ore bin.

[0025] Further, fine crushing cone crusher discharge port and heavy circular vibrating screen feed inlet, vertical shaft impact crusher discharge port and double-layer linear screen feed inlet are all connected by belt conveyor.

[0026] The utility model also provides the application of the above-mentioned efficient and environment-friendly mechanism fine sand production method and production system, the method and system are applied to the production of mud-containing mother rock, stone or waste stone with 6% < mud content < 16% or clay plasticity index of 1-10.

[0027] The utility model discloses the beneficial effect: the utility model discloses the sand making process system of dry and wet combination is higher, and the mud content is controlled through " wet type screening + two section sand washing " desliming process system, and the water content is controlled by mechanical dewatering equipment and gravity dewatering combination, and the three section crushing is combined with " wet type rod mill + dry type crushing and shaping " sand making process system to adjust mechanism fine sand gradation and stone powder content, so that the mud content, water content, gradation, stone powder content and other finished product quality indexes of finished product sand can be controlled better, guarantee the finished product mechanism fine sand quality, have the advantages such as small one-time investment, low operation management cost, coarse aggregate surface clean, less fine aggregate stone powder loss, can effectively reduce the dust pollution brought by dry sand making simultaneously, realize the recycling of stone powder and waste water, and the whole mechanism fine sand production is efficient and clean, has strong popularization and application value. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is the flow chart of the efficient and environment-friendly mechanism fine sand production method of example 1;

[0029] Figure 2 It is the equipment correlation diagram of the efficient and environment-friendly mechanism fine sand production system of example 2;

[0030] In the drawing: 1-bar strip feeder;2-linear vibrating screen I;3-slotted sand washer;4-high-efficiency thickener;5-plate-and-frame filter press;6-rod mill;8-high-frequency dewatering screen;9-jaw crusher;10-medium crushing cone crusher;11-linear vibrating screen II;13-fine crushing cone crusher;14-heavy circular vibrating screen;15-vertical shaft impact crusher;16-double-layer linear screen;17-division bin. DETAILED DESCRIPTION

[0031] In order to make the technical problem, technical scheme solved by the utility model more clearly, the utility model is further explained in detail in the following with the drawings and examples.It should be understood that the specific examples described here are only used to explain the utility model, and are not used to limit the utility model. Example 1

[0032] The embodiment provides an efficient and environment-friendly mechanism fine sand production method, which comprises the following steps:

[0033] (1) Feeding and screening: the ore is wetted by high pressure washing water of 0.3-0.5 MPa to disperse the slime, and the material is screened by a bar feeder to obtain +60 mm oversize material and -60 mm undersize material;

[0034] (2) First-stage screening and washing: the -60 mm undersize material is subjected to first-stage screening and washing by high pressure washing water of 0.3-0.5 MPa to further disperse the slime and separate the slime and boulders, to obtain +20 mm oversize material I and -20 mm undersize material I;

[0035] (3) Coarse crushing, intermediate crushing and screening: the +60 mm oversize material is subjected to open-circuit coarse crushing, and the coarse crushing product is combined with the +20 mm oversize material I from the first-stage screening and washing to be subjected to intermediate crushing; the intermediate crushing product is subjected to screening and washing by high pressure washing water of 0.3-0.5 MPa to obtain +20 mm oversize material II and -20 mm undersize material II;

[0036] (4) Second-stage sand washing: the -20 mm undersize material I from the first-stage screening and washing and the -20 mm undersize material II from the intermediate crushing are combined to be subjected to second-stage sand washing to separate the slurry and clean sand;

[0037] (5) Fine crushing and closed-circuit screening: the +20 mm oversize material II from the intermediate crushing is subjected to fine crushing, and the fine crushing product is subjected to screening to obtain +15 mm oversize material and -15 mm undersize material; the +15 mm oversize material is returned to the fine crushing equipment for fine crushing and screening until all the material is fine crushed to -15 mm qualified product;

[0038] (6) Wet rod milling and dehydration: the clean sand from the second-stage sand washing and part of the -15 mm undersize material from the fine crushing are combined to be subjected to wet rod milling to obtain 0.2-2.5 mm finished water-washed sand after dehydration;

[0039] (7) Crushing, shaping and grading: part of the -15 mm undersize material from the fine crushing is subjected to crushing and grain shape modification, and then subjected to double-deck screening to obtain 10-15 mm finished coarse aggregate as the oversize product from the upper deck, 4.75-10 mm finished medium coarse aggregate as the oversize product from the lower deck, and 0-4.75 mm machine-made fine sand as the undersize product from the lower deck;

[0040] (8) Slurry dehydration: the slurry from the second-stage sand washing and the slurry from the dehydration of the rod milling product are subjected to concentration and pressure filtration to obtain fine sludge and overflow water, and the overflow water can be recycled after clarification by sedimentation.

[0041] The utility model discloses a dry-wet combined sand making process, wherein, the sand washing and desliming adopts a "wet screening + two-stage sand washing" process, the stone crushing adopts a "coarse crushing - medium crushing - fine crushing" three-stage crushing process, and the sand making adopts a "wet rod mill + dry crushing and shaping" process.

[0042] The utility model discloses the control situation of the key technical index of mechanism fine sand production process technology, and specifically as follows:

[0043] (1) the control of the mud content of finished sand and coarse aggregate

[0044] Since the methylene blue MB value of mechanism sand is proportional to the clay content, when the MB value exceeds the critical value 1.4, the workability of fresh concrete is significantly reduced, the early plastic cracking degree is increased, and the flexural strength and 7d compressive strength of hardened concrete are obviously reduced. Therefore, it is necessary to remove the clay or fine mud in the sand making stone.

[0045] For this, the utility model discloses the "wet screening + two-stage sand washing" desliming process and crushing process are organically combined, and the high-pressure flushing water screen washing is carried out on the raw stone, the stone after coarse crushing and medium crushing, so that the clay or fine mud adhered to the surface of the product is effectively removed, the mud content of each particle size product is less than 1%, and favorable conditions are created for the preparation of subsequent sand and aggregate.

[0046] (2) the control of the moisture content of finished sand and coarse aggregate

[0047] The utility model discloses the "wet rod mill + dry crushing and shaping" process is adopted in the sand making, wherein, the fine crushing and crushing and shaping adopt dry crushing, and although the rod mill adopts wet grinding, the rod mill product is treated by high-frequency dehydration screen dehydration, therefore, the moisture content of the coarse aggregate, mechanism fine sand and washed sand obtained by the sand making process is low, and can be controlled within 10%. Moreover, when the finished sand is stored in the finished sand bin, the moisture content can be reduced to the related technical requirements after gravity dehydration and natural ventilation.

[0048] (3) optimization and control of particle size distribution

[0049] Particle gradation refers to the proportion of particles of various sizes in the aggregate. The uninterrupted particle sizes are referred to as continuous gradation, and the particle sizes composed of only several sizes are referred to as discontinuous gradation. Reasonable particle gradation is an important way to obtain low porosity or low air content of the aggregate. In order to solve the problems of coarse gradation of dry sand and low content of stone powder of-0.16 mm in wet sand, the utility model discloses a sand making process of "wet rod mill + dry crushing and shaping" to produce mechanism sand of different gradations and output, and then the mixture is prepared to solve the problems. Of course, the finished aggregate gradation can be adjusted according to the specific requirements of the downstream users, and the production of different particle size aggregates can be realized by adjusting the size of the middle crushing ore outlet, the fine crushing ore outlet and the linear screen mesh, adjusting and distributing the feeding amount of the rod mill sand and the crushing and shaping sand and the like.

[0050] (4) Control of stone powder content

[0051] Stone powder is a fine particle powder of-0.16 mm (specific surface area 325 m² / kg) produced in the crushing process of parent rock, and the stone powder can replace fly ash as an admixture to prepare concrete. Different from fine mud, the methylene blue MB value of the stone powder is less than 1.4, and the stone powder is defined as stone powder. In the utility model, the coarse crushing and the middle crushing adopt a wet process, and a small amount of stone powder produced in the process enters the slurry together with the fine mud in the sand washing process; the fine crushing and the crushing and shaping adopt a dry process, and the stone powder produced in the process can directly enter the finished sand and stone, and the appropriate amount of stone powder can effectively improve the impermeability, frost resistance and durability of the concrete and improve the workability of the concrete. Similarly, the stone powder content in the finished sand can be controlled by reasonably adjusting and distributing the feeding amount of the rod mill sand and the crushing and shaping sand.

[0052] (5) Control of particle shape of finished sand and stone aggregate

[0053] The particle shape of the finished sand and stone aggregate, especially the coarse aggregate, is related to the structure of the parent rock, the crushing process and the performance of the equipment, and it is difficult to avoid a certain amount of needle and flake aggregate. In the utility model, the coarse crushing adopts jaw crusher open circuit crushing to-180 mm, the middle and fine crushing adopt cone crusher full feeding and layering closed circuit crushing, the stability of the cone crusher is good, the particle shape of the crushing product is uniform, the discharge adjustment range is wide, and the flexibility in adjusting the product gradation is large, the wet screen washing is arranged after the middle crushing, and the dry closed circuit screening is arranged after the fine crushing, and the dry and wet combination is adopted. A part of the fine crushing-15 mm particle size enters the vertical shaft impact crusher for crushing and shaping (four-stage crushing), the feeding gradation is continuous, the materials are mutually impacted and shaped in the whole crushing and shaping process, the particle shape of the product is cubic, and the flake and needle particles are few (content less than about 5%). The crushing product gradation is continuous, the dry screening is carried out through the double-layer linear screen, and three finished products of 0~4.75 mm fine sand, 4.75~10 mm medium and coarse aggregate and 10~15 mm coarse aggregate are produced.

[0054] (6) Disposal of sand washing mud

[0055] The dry-wet combined process can overcome the dust pollution problem of dry sand making, and can reduce water consumption of wet sand making, and belongs to a green and environment-friendly sand making process. After concentration and pressure filtration, the sand washing mud realizes drainage treatment, and the overflow water can be returned to a sand washing water point for recycling after sedimentation and clarification, so that new water consumption can be further reduced.

[0056] In summary, the dry-wet combined sand making process has a high sand making rate, the mud content is controlled by sand washing and desliming, the water content is controlled by mechanical dehydration and gravity dehydration, and the fineness modulus and stone powder content of the finished sand are adjusted by dry-wet combined sand making, so that the mud content, water content, gradation and stone powder content of the finished sand can be well controlled, the quality of the finished machine-made fine sand is ensured, and the machine-made fine sand has the advantages of small one-time investment, low operation and management cost, clean coarse aggregate surface, less fine aggregate stone powder loss and the like. Meanwhile, the dust pollution caused by dry sand making can be effectively reduced, the recycling of stone powder and waste water is realized, the production of the machine-made fine sand is efficient and clean, and the machine-made fine sand has strong popularization and application value. Example 2

[0057] The embodiment provides a kind of efficient environmental protection production system of machine-made fine sand used in above-mentioned example 1, including bar type feeder 1, bar type feeder 1 screen underfeed is connected to linear vibrating screen I 2, bar type feeder 1 screen upper feed is connected to jaw crusher 9;Jaw crusher 9 lower feed and the screen upper feed of linear vibrating screen I 2 All are connected to medium crushing cone crusher 10 by belt machine and buffer ore bin, and the lower feed of medium crushing cone crusher 10 is connected to linear vibrating screen II 11;

[0058] The screen underfeed of linear vibrating screen I 2 And the screen underfeed of linear vibrating screen II 11 All are connected to tank sand washer 3, and the screen underfeed of linear vibrating screen II 11 It is connected to the feed inlet of tank sand washer 3 by slurry tank and slurry pump;Tank sand washer 3 clean sand outlet is connected to rod mill 6, and the discharge port of rod mill 6 is connected to high-frequency dehydration screen 8 by slurry tank and slurry pump;Tank sand washer 3 mud outlet and high-frequency dehydration screen 8 slurry port are sequentially connected to high-efficiency thickener 4, plate and frame filter press 5;

[0059] Linear vibrating screen II 11 Screen upper feed is connected to fine crushing cone crusher 13, and the discharge port of fine crushing cone crusher 13 is connected to the feed inlet of heavy circular vibrating screen 14 by belt machine, and the screen upper feed of heavy circular vibrating screen 14 is connected to the feed inlet of fine crushing cone crusher 13 by belt machine and buffer ore bin, and the screen underfeed of heavy circular vibrating screen 14 is connected to rod mill 6 and vertical shaft impact crusher 15, and the discharge port of vertical shaft impact crusher 15 is connected to the feed inlet of double-layer linear screen 16 by belt machine.

[0060] Further, the heavy circular vibrating screen 14 is further provided with a distribution bin 17 between the discharge port of the heavy circular vibrating screen 14 and the inlet of the distribution bin 17, and between the discharge port of the distribution bin 17 and the inlet of the rod mill 6, and the discharge port of the distribution bin 17 is further provided with a buffer ore bin between the inlet of the vertical shaft impact crusher 15.

[0061] It should be further noted that the above-mentioned devices are all existing devices, and the utility model does not involve the modification of the device, and only involves the use of the above-mentioned existing device. Of course, the finished aggregate gradation can be realized by adjusting the discharge port of the medium crushing cone crusher 10, the discharge port of the fine crushing cone crusher 13, the linear vibrating screen, the heavy circular vibrating screen and the double-layer linear screen mesh size, adjusting and distributing the feeding amount of the rod mill and the vertical shaft impact crusher and the like to produce different particle size aggregates. The control of the stone powder content in the finished sand can be realized by reasonably adjusting and distributing the feeding amount of the rod mill and the vertical shaft impact crusher.

[0062] Working principle: (1) Feeding and screening: the waste rock is fed into the rod bar feeder 1, the mineral mud is dispersed and screened by using 0.3-0.5MPa high-pressure washing water, and +60mm screen oversize material and-60mm screen undersize material are obtained.

[0063] (2) First-stage screening and washing: the-60mm screen undersize material of the rod bar feeder 1 is transferred to the linear vibrating screen I 2 for first-stage screening and washing, the mineral mud is further dispersed, and the mineral mud and the block stone are separated, and +20mm screen oversize material I and-20mm screen undersize material I are obtained.

[0064] (3) Coarse crushing, medium crushing and screening: the +60mm screen oversize material of the rod bar feeder 1 is transferred to the jaw crusher 9 for coarse crushing, the coarse crushing product and the +20mm screen oversize material I of the first-stage screening and washing are transferred to the medium crushing cone crusher 10 for medium crushing through the belt conveyor and the buffer ore bin; the medium crushing product is transferred to the linear vibrating screen II 11, and the medium crushing product is screened and washed by using 0.3-0.5MPa high-pressure washing water, and +20mm screen oversize material II and-20mm screen undersize material II are obtained.

[0065] (4) Second-stage sand washing: the-20mm screen undersize material I of the first-stage screening and washing and the-20mm screen undersize material II of the medium crushing screening and washing are combined and transferred to the trough sand washer 3 for second-stage sand washing operation, and mud and clean sand are separated.

[0066] (5) Fine closed-circuit screening: the +20mm oversize material II is transferred to the buffer bin and then to the fine cone crusher 13 for fine crushing. After fine crushing, the material is transferred to the heavy circular vibrating screen 14 for screening, obtaining +15mm oversize material and -15mm undersize material. The +15mm oversize material is returned to the fine cone crusher 13 by the belt conveyor for fine crushing and screening until all the material is fine crushed to -15mm qualified product.

[0067] (6) Wet rod milling and dewatering: the clean sand of the second-stage sand washing and the part of -15mm undersize material of fine crushing and screening (through the material distribution bin 17 and the belt conveyor) are transferred to the rod mill 6 for wet rod milling. The rod milling product is transferred to the high-frequency dewatering screen 8 through the slurry tank and the slurry pump for dewatering. The dewatered product is the washed sand (0.2-2.5mm).

[0068] (7) Crushing, shaping and grading: the part of -15mm undersize material of fine crushing and screening is transferred to the vertical shaft impact crusher 15 through the buffer bin for crushing and grain shape modification, and then transferred to the double-deck linear screen 16 by the belt conveyor for double-deck screening, obtaining 10-15mm finished coarse aggregate as the upper screen oversize product, 4.75-10mm finished medium coarse aggregate as the lower screen oversize product, and 0-4.75mm machine-made fine sand as the lower screen undersize product.

[0069] (8) Mud dewatering: the mud of the second-stage sand washing and the slurry of the rod milling product dewatering are transferred to the high-efficiency thickener 4 for thickening, and then to the plate-and-frame filter press 5 for pressure filtration, obtaining fine mud and overflow water. The overflow water is clarified after sedimentation in the recovery tank and can be recycled.

[0070] The production system is designed according to the production method of embodiment 1, has the matching equipment corresponding to the mud removal process of "wet screening + two-stage sand washing", the three-stage crushing process of "coarse crushing - medium crushing - fine crushing", and the sand making process of "wet rod milling + dry crushing and shaping", and can be applied to the production of mud-free, 6%< mud content < 16% or clay plasticity index 1-10 mud-containing mother rock, stone or waste stone.

[0071] The production system controls the mud content through the sand washing and mud removal equipment, controls the water content by combining the mechanical dewatering equipment with the gravity dewatering, and adjusts the fineness modulus and stone powder content of the finished sand by the dry and wet combined sand making equipment, so that the mud content, water content, grading, stone powder content and other finished product quality indexes of the finished sand can be well controlled, the sand making rate is high, the quality of the finished machine-made fine sand is good, and the production system has the advantages of small one-time investment, low operation and management cost, clean coarse aggregate surface, less fine aggregate stone powder loss, etc. At the same time, the production system can effectively reduce the dust pollution caused by dry sand making, realize the recycling of stone powder and waste water, and has strong popularization and application value.

[0072] Application example 1

[0073] A certain sand and gravel aggregate plant, the processing scale is 3000t / d, stone is open-pit mining stripping waste rock, mainly to limestone, crushing work index is about 14.70kW·h / t, raw material slurry content is about 8%.

[0074] The above stone is made into sand by the method described in Example 1 and / or the system described in Example 2, and the "wet screening + two-stage sand washing" desliming, "coarse crushing - medium crushing - fine crushing" three-stage crushing, "wet rod mill + dry crushing and shaping" sand making are adopted. The main equipment selection in the production process is: 1 C100 jaw crusher produced by Metso Outotec Company is selected for coarse crushing, which is used to process +60mm~+650mm particle size of mine waste rock from quarry; 1 HP300 type hydraulic cone crusher produced by Metso Outotec Company is selected for medium crushing, which is used to process-180mm coarse crushing products and the screen oversize material of the first stage screen washing; HP300 fine crushing type hydraulic cone crusher produced by Metso Outotec Company is selected for fine crushing, and B6150SE type vertical shaft impact crusher produced by Metso is selected for crushing and shaping, and BM2740 wet rod mill is selected for wet sand making equipment. The main technical indicators of the finished product are shown in Table 1:

[0075] Table 1: Main technical indicators of sand making finished product

[0076]

[0077] Among them, 0~0.2mm stone powder is washed out, fine mud accounts for about 16%, and the yield is about 480t / d.

[0078] The fineness modulus of the finished fine aggregate is between 2.3~3.0, the gradation is continuous, the stone powder content is between 10%~18%, the warehouse moisture content is controlled at about 10%, and the moisture content can be reduced to less than 6% after gravity dewatering and natural ventilation. The production water return rate is ≥80%, and the electricity consumption is about 3.5 degrees / t. The finished sand meets the requirements of mine underground filling sand and gravel aggregate.

[0079] Application Example 2

[0080] A certain hydropower sand and gravel plant is located near the dam site of a hydropower station, with abundant water resources. The processed stone is mainly granite and limestone, the rock hardness belongs to medium hardness, the parent rock abrasiveness is medium, and the design processing capacity is 550t / h.

[0081] The original production process adopts dry sand making, and through the processes of "pre-screening-coarse crushing-medium crushing-fine crushing", the raw ore of-150 mm is screened and removed before coarse crushing, one Sandvik CJ612 jaw crusher is used for coarse crushing, and the discharge port CSS=150 mm; one Sandvik CS440C cone crusher is used for medium crushing, the eccentricity is 36 mm, and the tight edge discharge port CSS=44 mm; the-5 mm fine aggregate is produced by pre-screening before fine crushing, two CH440MF fine crushing type cone crushers are used for fine crushing, the eccentricity is 44 mm, the tight edge discharge port CSS=22 mm, two double straight line screens are selected to form closed circuit screening with fine crushing, the+31.5 mm material on the upper screen is returned to fine crushing, the 20~30 mm material on the lower screen is transported to the finished product yard to produce 20~30 mm coarse aggregate, the-20 mm material on the lower screen is transported to the double straight line screen for secondary screening, the 10~20 mm finished product aggregate on the secondary screening is transported to the yard for storage, and the-10 mm material is used for crushing and shaping with two Sandvik SC2462 vertical shaft impact crushers and two straight line screens, the+5 mm product on the crushing and shaping is returned to the vertical shaft impact crusher, and the-5 mm product is produced into-5 mm finished sand after adjusting the content of fine sand and stone powder by two powder separators.

[0082] In the actual production process, because the raw material contains a large amount of mud, the dry sand making causes the process to be not smooth in the rainy season, the finished sand (0~5 mm) has a low sand production rate, the gradation is unbalanced, the finished product contains excessive mud, and the like.

[0083] After the sand making is performed by using the method in Example 1 and / or the system in Example 2, the fineness modulus of the finished sand is controlled at about 2.8, and the stone powder content is controlled at 14%, so that the problems of the process being not smooth in the rainy season, the finished product containing excessive mud, the gradation being unbalanced, and the production dust, which exist in the production of aggregate by using granite and limestone as raw materials, are solved. The main technical index comparison of the two sand making methods is shown in Table 2.

[0084] Table 2: Main technical index comparison of two sand making methods

[0085]

[0086] As shown in Table 2, the method can obtain ideal finished sand and stone by using different lithological mother rocks such as limestone, granite and limestone for sand making, the finished sand and stone has continuous gradation, the stone powder content is reasonable, and the needs of concrete production can be met.

[0087] The utility model is described in detail through specific and preferred examples, but those skilled in the art should understand that the utility model is not limited to the above examples, and any modification, equivalent replacement and the like made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A high-efficiency and environmentally friendly mechanism of producing fine sand production system, characterized in that, It includes a bar feeder (1), the bar feeder (1) is connected to linear vibrating screen I (2) through the under-screen outlet, and the bar feeder (1) is connected to the jaw crusher (9) through the over-screen outlet; the under-screen outlet of the jaw crusher (9) and the over-screen outlet of the linear vibrating screen I (2) are connected to the medium crushing cone crusher (10), and the under-screen outlet of the medium crushing cone crusher (10) is connected to the linear vibrating screen II (11); The under-screen outlets of the linear vibrating screen I (2) and the linear vibrating screen II (11) are connected to the tank sand washer (3), the clean sand outlet of the tank sand washer (3) is connected to the rod mill (6), the discharge outlet of the rod mill (6) is connected to the high-frequency dehydration screen (8); the mud outlet of the tank sand washer (3) and the slurry outlet of the high-frequency dehydration screen (8) are sequentially connected to the high-efficiency thickener (4) and the plate-and-frame filter press (5); The over-screen outlet of the linear vibrating screen II (11) is connected to the fine crushing cone crusher (13), the discharge outlet of the fine crushing cone crusher (13) is connected to the heavy circular vibrating screen (14), the over-screen outlet of the heavy circular vibrating screen (14) is connected to the feed inlet of the fine crushing cone crusher (13), and the under-screen outlet of the heavy circular vibrating screen (14) is connected to the rod mill (6) and the vertical shaft impact crusher (15); the discharge outlet of the vertical shaft impact crusher (15) is connected to the double-layer linear screen (16).

2. The high-efficiency environmentally friendly mechanical concentrate production system according to claim 1, characterized in that, The under-screen outlet of the jaw crusher (9) and the feed inlet of the medium crushing cone crusher (10), the over-screen outlet of the linear vibrating screen I (2) and the feed inlet of the medium crushing cone crusher (10), and the over-screen outlet of the heavy circular vibrating screen (14) and the feed inlet of the fine crushing cone crusher (13) are connected through the belt conveyor and the buffer ore bin.

3. The high-efficiency environmentally friendly mechanical concentrate production system according to claim 1, characterized in that, The under-screen outlet of the linear vibrating screen II (11) and the feed inlet of the tank sand washer (3), and the discharge outlet of the rod mill (6) and the feed inlet of the high-frequency dehydration screen (8) are connected through the ore slurry tank and the slurry pump.

4. The high-efficiency environmentally friendly mechanical concentrate production system according to claim 1, characterized in that, The under-screen outlet of the heavy circular vibrating screen (14) and the rod mill (6) are further provided with a distribution bin (17), the under-screen outlet of the heavy circular vibrating screen (14) and the feed inlet of the distribution bin (17), the discharge outlet of the distribution bin (17) and the feed inlet of the rod mill (6) are connected through the belt conveyor, and the discharge outlet of the distribution bin (17) and the feed inlet of the vertical shaft impact crusher (15) are further provided with the buffer ore bin.

5. The high-efficiency environmentally friendly mechanical concentrate production system according to claim 1, characterized in that, The discharge outlet of the fine crushing cone crusher (13) and the feed inlet of the heavy circular vibrating screen (14), and the discharge outlet of the vertical shaft impact crusher (15) and the feed inlet of the double-layer linear screen (16) are connected through the belt conveyor.

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