Middling closed-circuit grinding method and system based on lithium ore

Abstract

The invention provides a middling closed-circuit grinding method and system based on lithium ore. The method comprises the following steps: crushing and screening the lithium ore; feeding the undersize small-particle ore pulp and the magnetic tailing pulp product into a concentration pump tank to obtain mixed pulp before concentration; feeding into a thickener for concentration operation, and feeding into a hydraulic cyclone pump pool; the middlings are fed into an ore grinding machine for ore grinding operation and fed into a hydraulic cyclone pump pool to be mixed with the concentrated ore pulp product, and ore grinding slurry is obtained; and conveying the ore grinding slurry into a hydrocyclone for grading operation, feeding a graded underflow product into an ore grinding machine, and feeding the graded underflow product into a pump pool of the hydrocyclone so as to feed the graded underflow product into the hydrocyclone, thereby forming closed-loop ore grinding cycle operation. Closed-circuit ore grinding is adopted, the ore grinding efficiency is high, the product quality is stable, the ore grinding yield is large, meanwhile, the ore dressing quality of ore pulp after ore grinding can be guaranteed, and the problems that an existing open-circuit ore grinding method is relatively low in production efficiency and small in ore grinding yield are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of smelting engineering. Specifically, it relates to a closed-circuit grinding method and system for middlings based on lithium ore. Background Art

[0002] In current ore dressing methods, most adopt the open-circuit grinding method. That is, in the grinding operation, after the middlings enter the ball mill and are discharged after one-time grinding, they directly enter the next process. This grinding method has a simple process, low input cost, relatively low production efficiency, and high energy consumption. Summary of the Invention

[0003] In view of this, the present invention proposes a closed-circuit grinding method and system for middlings based on lithium ore, aiming to solve the problems of relatively low production efficiency and small grinding output of the existing open-circuit grinding method.

[0004] On the one hand, the present invention proposes a closed-circuit grinding method for middlings based on lithium ore. The method includes the following steps: a crushing and screening step, in which the lithium ore is subjected to a crushing and screening operation to obtain middlings and divide them into two paths, A and B; a heavy medium sizing screen operation step, in which the middlings and water in path A are fed into a heavy medium sizing screen for sizing operation to obtain undersize pulp and oversize products on the screen. The oversize products on the screen are subjected to a heavy medium separation operation to obtain magnetic tailing pulp products; a mixing operation step, in which the undersize pulp and the magnetic tailing pulp products are fed into a thickening pump pool to obtain a pre-thickening mixed slurry; a thickening operation step, in which the pre-thickening mixed slurry in the thickening pump pool is fed into a thickener for thickening operation to obtain thickened ore pulp products and fed into a hydrocyclone pump pool; a grinding operation step, in which the middlings in path B are fed into a grinding mill, mixed with the products in the grinding mill and subjected to a grinding operation to obtain grinding products, and fed into a hydrocyclone pump pool to obtain grinding pulp; a classification operation step, in which the grinding pulp in the hydrocyclone pump pool is transported to a hydrocyclone for classification operation. After the classification operation, classification overflow products and classification underflow products are obtained, and the classification underflow products are fed into the grinding mill for grinding operation again to obtain grinding products, and then fed into the hydrocyclone pump pool again to be fed into the hydrocyclone for classification operation again to form a closed-circuit grinding cycle operation.

[0005] Further, the above-mentioned closed-circuit grinding method for middlings based on lithium ore further includes the following steps: a concentrate treatment step, in which the classification overflow products are transported to a pulp de-sliming and sand-settling ore dressing system for pulp de-sliming and sand-settling operations and flotation dehydration ore dressing operations to obtain lithium concentrate and beryllium concentrate.

[0006] Further, in the above-mentioned closed-circuit grinding method for middlings of lithium ore, the middlings in Route A are fed into a heavy medium sizing screen through a first conveyor for sizing operation; the large-sized products on the screen are fed into a heavy medium treatment system through a second conveyor for heavy medium separation operation; and the middlings in Route B are fed into a grinding mill through a third conveyor for grinding operation.

[0007] Further, in the above-mentioned closed-circuit grinding method for middlings of lithium ore, the first conveyor, the second conveyor, and / or the third conveyor is / are belt conveyors.

[0008] Further, in the above-mentioned closed-circuit grinding method for middlings of lithium ore, the grinding mill is a wet overflow type ball mill.

[0009] On the other hand, the present invention also proposes a closed-circuit grinding system for middlings of lithium ore, which system includes: a crushing and sizing module for obtaining middlings by crushing and sizing lithium ore and dividing them into two routes, Route A and Route B; a sizing operation module for feeding the middlings in Route A and water into a heavy medium sizing screen for sizing operation to obtain small-sized slurry under the screen and large-sized products on the screen, and performing heavy medium separation operation on the large-sized products on the screen to obtain magnetic tailing slurry products; a mixing operation module for feeding the small-sized slurry under the screen and the magnetic tailing slurry products into a thickening pump sump to obtain a pre-thickened mixed slurry; a thickening operation module for feeding the pre-thickened mixed slurry in the thickening pump sump into a thickener for thickening operation to obtain thickened ore slurry products and feeding them into a hydrocyclone pump sump; a grinding operation module for feeding the middlings in Route B into a grinding mill for grinding operation to obtain ground products and feeding them into the hydrocyclone pump sump to be mixed with the thickened ore slurry products to obtain grinding slurry; and a classification operation module for transporting the grinding slurry in the hydrocyclone pump sump to a hydrocyclone for classification operation. After the classification operation, classified overflow products and classified underflow products are obtained, and the classified underflow products are fed into the grinding mill for grinding operation to obtain ground products and fed into the hydrocyclone pump sump to be fed into the hydrocyclone again for classification operation to form a closed-circuit grinding cycle operation.

[0010] Further, in the above-mentioned closed-circuit grinding system for middlings of lithium ore, the system further includes: a concentrate treatment module for transporting the classified overflow products to a pulp de-sludging and sand-settling ore dressing system for pulp de-sludging and sand-settling operation and flotation dehydration ore dressing operation to obtain lithium concentrate and beryllium concentrate.

[0011] Further, in the above-mentioned closed-circuit grinding system for middlings of lithium ore, the middlings in Route A are fed into a heavy medium sizing screen through a first conveyor for sizing operation; the large-sized products on the screen are fed into a heavy medium treatment system through a second conveyor for heavy medium separation operation; and the middlings in Route B are fed into a grinding mill through a third conveyor for grinding operation.

[0012] Further, in the above-mentioned closed-circuit grinding system for middlings based on lithium ore, the first conveyor, the second conveyor, and / or the third conveyor is a belt conveyor.

[0013] Further, in the above-mentioned closed-circuit grinding system for middlings based on lithium ore, the grinding mill is a wet overflow ball mill.

[0014] In the closed-circuit grinding method and system for middlings based on lithium ore provided by the present invention, during the grinding operation, after the middlings enter the grinding mill and are ground once, they enter a hydrocyclone for classification. The middlings with unqualified particle size are returned to the grinding mill for grinding again, and the pulp with qualified particle size enters the next process. The advantage of closed-circuit grinding is high grinding efficiency, stable product quality, large grinding output. At the same time, the grinding fineness is -0.074 mm, which can also ensure the beneficiation quality of the pulp after grinding. Especially when using closed-circuit grinding in the grinding operation, the middlings and the -0.5 mm thickened underflow of the previous beneficiation stage enter the mill and are ground once, then enter the hydrocyclone for classification. The middlings with unqualified underflow particle size are returned to the mill for grinding again to achieve a continuous cyclic operation process. The pulp with qualified flotation particle size enters the next process. The advantage of closed-circuit grinding is high grinding efficiency, stable product quality, large grinding output. At the same time, the grinding fineness is -0.074 mm, which can also ensure the beneficiation quality of the pulp after grinding. On the premise of ensuring the beneficiation quality of the pulp, it realizes the production goals of high efficiency, energy conservation, and environmental protection, sets a precedent for closed-circuit grinding in high-altitude and cold regions, creates greater economic and social benefits for the mining enterprises in the Kunlun Mountains at an altitude of 4,600 meters, and promotes the sustainable green development of the lithium mining industry. At the same time, this method has high grinding efficiency, stable product quality, large grinding output, and can also ensure the beneficiation quality of the pulp after grinding, solving the problems of relatively low production efficiency and small grinding output in the existing open-circuit grinding method.

[0015] That is to say, after the intermediate ore passes through the heavy medium sizing screen, the small particle pulp under the screen and the magnetic tailing pulp product are fed into the thickening pump pool to obtain the mixed pulp before thickening; then it is fed into the thickener for thickening operation. The pulp is pumped into the hydrocyclone by the slurry pump, and the underflow is fed into the ball mill; the intermediate ore is fed into the grinding mill for grinding operation and then fed into the hydrocyclone pump pool to be mixed with the thickened pulp product to obtain the grinding pulp. At the same time, the intermediate ore (dry ore) is continuously fed into the ball mill for grinding operation through the belt conveyor. The intermediate ore (dry ore) and the hydrocyclone underflow pulp after the heavy medium sizing screen are mixed in the ball mill; the grinding pulp is transported to the hydrocyclone for classification operation, the classification underflow product is fed into the grinding mill, and the discharge end is fed into the pulp pool and then pumped into the hydrocyclone again by the slurry pump to form a closed-circuit grinding cycle operation. The present invention adopts closed-circuit grinding, which has high grinding efficiency, stable product quality, large grinding output, and can also ensure the ore dressing quality of the pulp after grinding, solving the problems of relatively low production efficiency and small grinding output in the existing open-circuit grinding method. Description of the Drawings

[0016] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0017] Figure 1 It is a flow block diagram of the closed-circuit grinding method for intermediate ore based on lithium ore provided by an embodiment of the present invention;

[0018] Figure 2 It is a process flow diagram of the closed-circuit grinding method for intermediate ore based on lithium ore provided by an embodiment of the present invention;

[0019] Figure 3 It is another flow block diagram of the closed-circuit grinding method for intermediate ore based on lithium ore provided by an embodiment of the present invention;

[0020] Figure 4 It is a process flow diagram of the multiple de-sludging steps provided by an embodiment of the present invention;

[0021] Figure 5 It is a process ore diagram of the multiple de-sludging steps provided by an embodiment of the present invention;

[0022] Figure 6 It is a structural block diagram of the closed-circuit grinding system for intermediate ore based on lithium ore provided by an embodiment of the present invention. Detailed Embodiments

[0023] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0024] Method Embodiment:

[0025] See Figures 1 to 2 , which shows the process flow of the closed-circuit grinding method for intermediate ore based on lithium ore provided by the embodiments of the present invention. As shown in the figure, the closed-circuit grinding method for intermediate ore can use the grinding and classification equipment 100 to perform grinding and classification operations on lithium ore to obtain the overflow product of grinding and classification. The method includes the following steps:

[0026] Crushing and Screening Step S1: The lithium ore is subjected to crushing and screening operations to obtain intermediate ore, which is divided into two paths, A and B.

[0027] Specifically, first, the lithium ore can be subjected to crushing and screening operations through a crushing and screening device (not shown in the figure) to obtain intermediate ore. Then, the intermediate ore is divided into two paths, A and B, to perform heavy medium separation and ball mill grinding operations respectively.

[0028] Screening Operation Step S2: The intermediate ore and water in Path A are fed into a heavy medium sizing screen for screening operations to obtain the small particle pulp under the screen and the large particle product on the screen. The large particle product on the screen is subjected to heavy medium separation operations to obtain the magnetic tailing pulp product.

[0029] Specifically, first, the middlings in Route A can be fed into the heavy medium sizing screen 102 in accordance with the quantity, that is, the sizing screen before heavy medium beneficiation. Water is injected into the heavy medium sizing screen 102 through the water injection pipe 103, so that water is mixed with the middlings fed by the first conveyor 101 for screening operation, obtaining the undersize fine particle pulp and the oversize large particle product on the screen; then, the oversize large particle product on the screen is fed into the heavy medium treatment system through the second conveyor 117. It can be first fed into the mixing tank before rough selection of heavy medium beneficiation for mixing operation with the added ferrosilicon powder, and then heavy medium separation operation is carried out. For example, the heavy medium mixture can be subjected to classification and medium removal screening operation in sequence to obtain concentrate pulp, medium removal screen underflow water and medium. The medium removal screen underflow water and medium are recycled. After concentration, magnetic separation is carried out by the magnetic separator 118 to obtain magnetic tailing pulp product and recover ferrosilicon powder water product. The recovered ferrosilicon powder water product is fed into the mixing tank for recycling. Among them, the oversize large particle product on the screen can be the product on the screen with a size of 0.5 - 6 mm, and the undersize fine particle pulp can be the mixed pulp of the product undersize 0.5 mm and water; the heavy medium sizing screen 102 can be a 4.3 m × 7.3 m vibrating screen.

[0030] Mixing operation step S3: Feed the undersize fine particle pulp and the magnetic tailing pulp product into the thickening pump sump to obtain the mixed slurry before thickening.

[0031] Specifically, the undersize fine particle pulp and the magnetic tailing pulp product can be fed into the thickening pump sump 105. The undersize fine particle pulp and the heavy medium concentrate product are mixed in the thickening pump sump 105 to obtain the mixed slurry before thickening. Among them, the undersize fine particle pulp can flow into the thickening pump sump 105 through the screening self-flow pipeline 104.

[0032] Thickening operation step S4: Feed the mixed slurry before thickening in the thickening pump sump into the thickener for thickening operation to obtain the thickened pulp product, and feed it into the hydrocyclone pump sump.

[0033] Specifically, first, the mixed slurry before thickening in the thickening pump sump 105 can be pumped to the thickener 107 through the slurry pump pumping pipeline 106 for thickening operation. The underflow product obtained is the thickened pulp product; then, the underflow of the thickener 107 is pumped to the mill discharge pump sump in the grinding and flotation plant, that is, the hydrocyclone pump sump 109, through the slurry pump 108. Among them, the thickener 107 can be a fine particle thickener.

[0034] Grinding operation step S5: Feed the middlings in Route B into the grinding mill, mix with the product in the grinding mill and carry out grinding operation to obtain the grinding product, and feed it into the hydrocyclone pump sump to be mixed with the thickened pulp product to obtain the grinding slurry.

[0035] Specifically, 3 hydraulic flat gate valves are arranged under the pre-grinding buffer bin to feed the middlings in Route B to the third conveyor 113, and then to the grinding mill 111 in the grinding and flotation workshop through the third conveyor 113. In this embodiment, a weighing device is provided on the third conveyor 113, which has metering, accumulation, and control modes. By adjusting the speed (frequency conversion) of the third conveyor 113 and measuring the ore feeding to the grinding mill 111 through an electronic belt scale, the ore is fed quantitatively according to production requirements. Among them, the grinding mill 111 can be a wet overflow ball mill, especially a wet overflow Φ5.8m×10.4m ball mill.

[0036] In the classification operation step S6, the grinding pulp in the hydrocyclone pump sump is transported to the hydrocyclone for classification operation. After the classification operation, a classified overflow product and a classified underflow product are obtained. The classified underflow product is fed into the grinding mill for grinding operation to obtain a grinding product, which is then fed into the hydrocyclone pump sump to be fed again to the hydrocyclone for classification operation, forming a closed-circuit grinding cycle operation.

[0037] Specifically, the feeding concentration of the classification hydrocyclone 114, the overflow concentration and overflow flow rate of the overflow pipeline 115 are detected online; by adjusting the supplementary water in the hydrocyclone pump sump 109, the ore feeding concentration of the classification hydrocyclone 114 is stabilized. The liquid level in the hydrocyclone pump sump 109 and the ore feeding flow rate on the slurry pump conveying pipeline 116 are stabilized by the frequency conversion of the slurry pump. The cyclone pressure is adjusted by the automatic opening and closing of the classification hydrocyclone 114 to make the concentration and fineness of the overflow product in the overflow pipeline 115 meet the production requirements; the grinding mill 111 used in the grinding and flotation workshop can use 1 wet overflow Φ5.8m×10.4m ball mill for grinding operation. The grinding product obtained by the grinding of the grinding mill 111 enters the hydrocyclone pump sump 109 and is pumped to the classification hydrocyclone 114 through the slurry pump conveying pipeline 116 for classification operation; among them, the classification hydrocyclone 114 can be a group of Φ500-12 hydrocyclones, that is, the nominal diameter of the cyclone is 500 mm and the feed inlet diameter of the cyclone is 12 mm. The underflow product of the classification hydrocyclone 114 enters the grinding mill 111 from the classification flow through the pipeline 119; while the grinding mill 111 is rotating, the middlings at the feed end continuously enter the grinding mill 111 through the third conveyor 113, and the discharge end continuously discharges ore to the hydrocyclone pump sump 109, which is pumped to the classification hydrocyclone 114 through the slurry pump conveying pipeline 116 for classification operation; the classified overflow product of the classification hydrocyclone 114 can be ore smaller than 0.074 mm, and its content is about 79%, which is transported to the next pump sump operation through the overflow pipeline 115.

[0038] Among them, the first conveyor, the second conveyor, and / or the third conveyor is a belt conveyor.

[0039] See Figure 3 , which is another process flow diagram of the closed-circuit grinding method for intermediate ore based on lithium ore provided by the embodiment of the present invention. As shown in the figure, the method may further include the following steps:

[0040] Crushing and screening step S1: The lithium ore is subjected to crushing and screening operations to obtain intermediate ore, which is divided into two paths, A and B.

[0041] Screening operation step S2: The intermediate ore and water in path A are fed into a heavy medium sizing screen for screening operations to obtain undersize particle pulp and oversize product on the screen. The oversize product on the screen is subjected to heavy medium separation operations to obtain magnetic tailing pulp product.

[0042] Mixing operation step S3: The undersize particle pulp and the magnetic tailing pulp product are fed into a thickening pump sump to obtain the pre-thickening mixed slurry.

[0043] Thickening operation step S4: The pre-thickening mixed slurry in the thickening pump sump is fed into a thickener for thickening operations to obtain thickened ore pulp product, which is fed into a hydrocyclone pump sump.

[0044] Grinding operation step S5: The intermediate ore in path B is fed into a grinding mill, where it is mixed with the product inside the grinding mill and subjected to grinding operations to obtain grinding product, which is fed into the hydrocyclone pump sump and mixed with the thickened ore pulp product to obtain grinding slurry.

[0045] Classification operation step S6: The grinding slurry in the hydrocyclone pump sump is transported to a hydrocyclone for classification operations. After the classification operations, classification overflow product and classification underflow product are obtained. The classification underflow product is fed into the grinding mill for grinding operations, mixed with the thickened ore pulp product to obtain grinding product, and then fed into the hydrocyclone pump sump to be fed again to the hydrocyclone for classification operations, forming a closed-circuit grinding cycle operation.

[0046] Concentrate treatment step S7: The classification overflow product is transported to a pulp de-sliming and sand-settling ore dressing system for pulp de-sliming and sand-settling operations and flotation dehydration ore dressing operations to obtain lithium concentrate and beryllium concentrate.

[0047] Specifically, first, the classification overflow product of the classification hydrocyclone 114 can be fed through the overflow pipeline 115 into Figure 4The shown pulp desliming and sand settling beneficiation system 200 performs pulp desliming and sand settling beneficiation operations to obtain a underflow pulp product. Then, the underflow pulp product is fed by gravity into a flotation device. For example, it can be fed into the lithium roughing agitation tank 300 of the flotation device, or it can also be other agitation tanks or other devices, and the next operation, that is, the flotation operation, can be carried out. The ground ore can be formulated into a pulp with a suitable concentration by adjusting the pulp and adding reagents, and heating in a stirring tank, and the corresponding flotation reagents are added. Stirring is carried out through the stirring and aerating device of the flotation machine, and air is inhaled to generate a large number of bubbles with suitable sizes and relatively stable. After the pulp acts with the flotation agent, the surface hydrophobic ore particles can adhere to the bubbles and gradually float to the surface of the pulp to form mineralized foam. The rotating scraper of the flotation machine scrapes out the mineralized foam to obtain the corresponding lithium pulp and beryllium pulp. The product discharged subsequently remaining in the pulp is the flotation tailing pulp, which can be discharged into the tailing pulp pond 228. Among them, lithium pulp and beryllium pulp can be obtained through lithium separation and beryllium separation. Then, dehydration operations are respectively carried out on the lithium pulp and beryllium pulp to obtain lithium concentrate and beryllium concentrate.

[0048] See Figure 4 , which shows the preferred process flow of the desliming and sand settling operation of the pulp provided by the embodiment of the present invention. As shown in the figure, the desliming and sand settling operation of the pulp is specifically: multiple desliming and sand settling operations are sequentially carried out on the grinding and classification overflow product through a multi-stage hydrocyclone to obtain a sediment tailing pulp product and the underflow pulp products discharged from each stage of the hydrocyclone.

[0049] Specifically, multiple desliming and sand settling operations are sequentially carried out on the grinding and classification overflow product through a multi-stage desliming hydrocyclone to obtain the final overflow product, that is, the sediment tailing pulp product and the underflow pulp products discharged from each stage of the hydrocyclone. Among them, a desliming pulp pond is correspondingly provided upstream of each hydrocyclone; the grinding and classification overflow product can be fed into the primary desliming pulp pond and pumped into the primary hydrocyclone through a slurry pump; and the desliming slurry product obtained by carrying out the desliming and sand settling operation on the upper-stage hydrocyclone is fed into the desliming pulp pond corresponding to the lower-stage hydrocyclone and pumped into the lower-stage hydrocyclone through a slurry pump. In the embodiment, the hydrocyclone can be three-stage, that is, three desliming and sand settling operations are carried out through a three-stage hydrocyclone; of course, it can also be other stages and times, such as two-stage and two times, which can be determined according to the ore content in the overflow product, so that the ore content in the final overflow product, that is, the sediment tailing pulp product, is less than the threshold value, where the threshold value can be determined according to the actual situation.

[0050] In this embodiment, tailing treatment can also be carried out on the sediment tailing pulp product.

[0051] Specifically, the final overflow product, that is, the overflow product obtained through multiple desliming overflows, namely the sediment tailings slurry product, enters the tailings slurry pond 222 through the tail-stage floating flow pipeline 220. Meanwhile, tailings from other processes, such as the flotation tailings slurry from the flotation operation, can also be the tailings from other process operations and are sent into the tailings slurry pond 222 through the tailings gravity flow pipeline 226. The tailings slurry product in the tailings slurry pond 222 can enter the fourth slurry pump pre-pipeline 223 and then enter the fourth slurry pump 224. After being pressurized by the fourth slurry pump 224, the slurry is pumped by the fourth slurry pump pressure pipeline 225 to other equipment, such as a professional tailings thickener, for the next operation. In this embodiment, no limitation is imposed on the subsequent operations.

[0052] Continue to refer to Figure 4 and Figure 5 , the multiple desliming steps may include the following sub-steps:

[0053] Primary desliming sub-step S71: Feed the grinding classification overflow product into the first hydrocyclone, and obtain the primary sediment slurry product through overflow and the primary slurry product through underflow discharge.

[0054] Specifically, the classification overflow product discharged by the classification hydrocyclone 114 is fed into the first-stage desliming slurry pond, i.e., the first desliming slurry pond 201, through the overflow pipeline 115. The slurry enters the first desliming slurry pump pre-pipeline 202 and then enters the first desliming slurry pump 203. After being pressurized by the first desliming slurry pump 203, the slurry is pumped into the first hydrocyclone 205 through the first desliming slurry pump pressure pipeline 204 for the first desliming operation. The primary sediment slurry product is obtained through floating flow, and as a part of the underflow slurry product, the underflow is discharged to obtain the primary slurry product. Among them, the first hydrocyclone 205 can be a Φ250-20 hydrocyclone, that is, the nominal diameter of the hydrocyclone is 250 mm and the feed inlet diameter of the hydrocyclone is 20 mm.

[0055] Secondary desliming sub-step S72: Feed the primary sediment slurry product into the second hydrocyclone, and obtain the secondary sediment slurry product through overflow and the secondary slurry product through underflow discharge.

[0056] Specifically, the primary pulp product obtained from the first desliming operation by the first hydrocyclone 205 enters the lithium rougher agitation tank 300 of the flotation equipment through the first desliming underflow pipeline 206 of the first hydrocyclone 205 for the next process operation, i.e., the flotation operation; the primary sediment slurry product obtained from the first desliming operation by the first hydrocyclone 205 enters the second desliming pulp tank 208 through the first desliming overflow pipeline 207 of the first hydrocyclone 205. The pulp enters the second desliming slurry pump pre-pipeline 209 and then enters the second desliming slurry pump 210. After being pressurized by the second desliming slurry pump 210, the pulp is pumped into the second hydrocyclone 212 through the second desliming slurry pump pressure pipeline 211 for the second desliming operation. The overflow obtains the secondary sediment slurry product, which is part of the underflow pulp product, and the underflow is discharged to obtain the secondary pulp product. Among them, the first hydrocyclone 205 can be a Φ250-30 hydrocyclone, that is, the nominal diameter of the hydrocyclone is 250 mm and the feed inlet diameter of the hydrocyclone is 30 mm.

[0057] The third-level desliming sub-step S73: Feed the secondary sediment slurry product into the third hydrocyclone, and the overflow obtains the tertiary sediment slurry product as the sediment tailing slurry product, and the underflow is discharged to obtain the tertiary pulp product.

[0058] Specifically, the secondary pulp product obtained from the second desliming operation by the second hydrocyclone 212 enters the lithium rougher agitation tank 300 of the flotation equipment through the second desliming underflow pipeline 214 of the second hydrocyclone 212 for the next process operation, i.e., the flotation operation; the secondary sediment slurry product obtained from the second desliming operation by the second hydrocyclone 212 enters the third desliming pulp tank 215 through the second desliming overflow pipeline 213 of the second hydrocyclone 212. The pulp enters the third desliming slurry pump pre-pipeline 216 and then enters the third desliming slurry pump 217. After being pressurized by the third desliming slurry pump 217, the pulp is pumped into the third hydrocyclone 219 through the third desliming slurry pump pressure pipeline 218 for the third desliming operation. The overflow obtains the tertiary sediment slurry product, which is part of the underflow pulp product, and the underflow is discharged to obtain the tertiary pulp product. Among them, the third hydrocyclone 219 can be a Φ250-42 hydrocyclone, that is, the nominal diameter of the hydrocyclone is 250 mm and the feed inlet diameter of the hydrocyclone is 42 mm.

[0059] In this embodiment, the three-stage pulp product obtained by the third hydrocyclone 219 through the third desliming operation enters the lithium roughing agitation tank 300 of the flotation equipment through the underflow pipeline 221 of the third desliming of the third hydrocyclone 219 for the next process operation, i.e., the flotation operation; the three-stage sediment slurry product obtained by the second desliming operation of the third hydrocyclone 219 is used as the sediment tailing slurry product and enters the tailing pulp pool 222 through the third desliming overflow pipeline of the third hydrocyclone 219, i.e., the tail-stage overflow pipeline 220.

[0060] In this embodiment, the first hydrocyclone 205, the second hydrocyclone 212, and the third hydrocyclone 219 are based on a centrifugal force field. The fed product forms a rotational motion inside the hydrocyclone, so that the heavier ore particles are discharged as underflow products, and the lighter sediment particles overflow as overflow products. Due to the different particle sizes and densities of the sediment particles and ore particles, under the action of centrifugal force, the heavier ore particles move towards the cyclone wall and settle down along the wall to the bottom for discharge, while the lighter sediment particles move towards the center and overflow from the top, thus achieving the purpose of pulp desliming and sand sedimentation for ore dressing. Utilizing the density difference between the sediment particles and ore particles in the pulp and the liquid, the ore particles settle to the bottom under the action of gravity. Based on the action of the centrifugal force field, the pulp can be injected into the cyclone at a high speed in the tangential direction to form a strong rotational motion inside the cyclone.

[0061] In this embodiment, the flotation dehydration ore dressing operation may specifically include: performing flotation operations on the underflow pulp products of each stage of the hydrocyclone to obtain lithium pulp, beryllium pulp, and flotation tailing pulp, and respectively performing dehydration operations on the lithium pulp and beryllium pulp to obtain lithium concentrate and beryllium concentrate.

[0062] Specifically, the underflow pulp products of each stage of the hydrocyclone, i.e., the desliming underflow sand sedimentation products, are fed by gravity into the flotation equipment. For example, they can be fed into the lithium roughing agitation tank 300 of the flotation equipment, or it can be other agitation tanks or other equipment for the next operation, i.e., the flotation operation. The ground ore can be prepared into a pulp with an appropriate concentration by adjusting the pulp and adding drugs and heating in the agitation tank, and the corresponding flotation reagents are added. Stirring is carried out through the stirring aerator of the flotation machine, and air is inhaled to generate a large number of bubbles with appropriate sizes and relatively stable. After the pulp acts with the flotation agent, the surface-hydrophobic ore particles can adhere to the bubbles and gradually float to the surface of the pulp to form mineralized foam. The rotating scraper of the flotation machine scrapes off the mineralized foam to obtain the corresponding lithium pulp and beryllium pulp. The product discharged subsequently in the pulp is the flotation tailing pulp, which can be discharged into the tailing pulp pool 228. Among them, lithium pulp and beryllium pulp can be obtained through lithium separation and beryllium separation. Then, dehydration operations are respectively performed on the lithium pulp and beryllium pulp to obtain lithium concentrate and beryllium concentrate.

[0063] In this embodiment, when the same type of ball mill is grinding ore, it is required that the ore feeding be uniform and stable. Either too large or too small ore feeding amount will affect the improvement of grinding efficiency. At the same time, the grinding concentration also has a great influence on the technical efficiency of grinding. If the concentration is too high, the material will flow slowly in the mill, the grinding time will increase, and it is easy to be over-ground. If the pulp concentration is too dilute, the material flow rate will increase, the grinding time will be shortened, and the large-density ore particles are likely to deposit at the bottom layer of the pulp, which will also cause over-grinding. Therefore, during operation, an appropriate grinding concentration should be mastered, and the water consumption should also be strictly controlled.

[0064] In summary, for the closed-circuit grinding method of intermediate ore based on lithium ore provided in this embodiment, during the grinding operation, after the intermediate ore enters the grinding mill and undergoes primary grinding, it enters a hydrocyclone for classification. The intermediate ore with unqualified particle size is returned to the grinding mill for re-grinding, and the ore pulp with qualified particle size enters the next process. The advantage of closed-circuit grinding is high grinding efficiency, stable product quality, large grinding output. At the same time, the grinding fineness is -0.074mm, which can also ensure the ore dressing quality of the ore pulp after grinding. Especially when closed-circuit grinding is adopted during the grinding operation, the intermediate ore and the -0.5mm thickened underflow of the previous-stage ore dressing enter the mill and undergo primary grinding, then enter the hydrocyclone for classification. The intermediate ore with unqualified bottom-flow particle size is returned to the mill for re-grinding to realize a continuous cyclic operation process. The ore pulp with qualified floating-flow particle size enters the next process. The advantage of closed-circuit grinding is high grinding efficiency, stable product quality, large grinding output. At the same time, the grinding fineness is -0.074mm, which can also ensure the ore dressing quality of the ore pulp after grinding. On the premise of ensuring the ore dressing quality of the ore pulp, it realizes the production goals of high efficiency, energy conservation, and environmental protection, creating a precedent for closed-circuit grinding in high-altitude and cold regions, creating greater economic and social benefits for the mining enterprise at 4,600 meters on Kunlun Mountain, and promoting the sustainable green development of the lithium mining industry. At the same time, this method has high grinding efficiency, stable product quality, large grinding output, and can also ensure the ore dressing quality of the ore pulp after grinding, solving the problems of relatively low production efficiency and small grinding output of the existing open-circuit grinding method.

[0065] System embodiment:

[0066] See Figure 6, which is a structural block diagram of a closed-circuit grinding system for middlings based on lithium ore provided by an embodiment of the present invention. As shown in the figure, the system may include: a crushing and screening module 10, a screening operation module 20, a mixing operation module 30, a thickening operation module 40, a grinding operation module 50, a classification operation module 60, and a concentrate treatment module 70; among them, the crushing and screening module 10 is used to obtain middlings through crushing and screening operations on lithium ore and divide them into two paths, A and B; the screening operation module 20 is used to feed the middlings and water in path A into a heavy medium sizing screen for screening operations to obtain undersize particle pulp and oversize product on the screen, and perform heavy medium separation operations on the oversize product on the screen to obtain magnetic tailing pulp products; the mixing operation module 30 is used to feed the undersize particle pulp and magnetic tailing pulp products into a thickening pump sump to obtain a mixed slurry before thickening; the thickening operation module 40 is used to feed the mixed slurry before thickening in the thickening pump sump into a thickener for thickening operations to obtain thickened ore pulp products and feed them into a hydrocyclone pump sump; the grinding operation module 50 is used to feed the middlings in path B into a grinding mill, mix them with the products inside the grinding mill and perform grinding operations to obtain grinding products, and feed them into a hydrocyclone pump sump to obtain grinding pulp; the classification operation module 60 is used to transport the grinding pulp in the hydrocyclone pump sump to a hydrocyclone for classification operations. After the classification operations, classification overflow products and classification underflow products are obtained, and the classification underflow products are fed into the grinding mill for grinding operations again to obtain grinding products, and then fed into the hydrocyclone pump sump again to be fed into the hydrocyclone for classification operations again to form a closed-circuit grinding cycle operation; the concentrate treatment module 70 is used to transport the classification overflow products to a pulp desliming and sand settling beneficiation system for pulp desliming and sand settling operations and flotation dehydration beneficiation operations to obtain lithium concentrate and beryllium concentrate.

[0067] Preferably, the middlings in path A are fed into a heavy medium sizing screen for screening operations through a first conveyor; the oversize product on the screen is fed into a heavy medium treatment system for heavy medium separation operations through a second conveyor; the middlings in path B are fed into a grinding mill for grinding operations through a third conveyor.

[0068] Preferably, the first conveyor, the second conveyor, and / or the third conveyor is a belt conveyor.

[0069] Preferably, the grinding mill is a wet overflow ball mill.

[0070] In this embodiment, the principle of the closed-circuit grinding method for middlings and the closed-circuit grinding system for middlings is the same, and the relevant parts can be referred to each other.

[0071] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0072] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A closed-circuit grinding method for middlings based on lithium ore, characterized in that, It includes the following steps: The crushing and screening step: subjecting lithium ore to crushing and screening operations to obtain intermediate ore, which is divided into two paths, namely path A and path B; The heavy medium sizing screen operation step: feeding the intermediate ore in path A and water into a heavy medium sizing screen for screening operations to obtain undersize fine particle pulp and oversize large particle products, and subjecting the oversize large particle products to heavy medium separation operations to obtain magnetic tailing pulp products; The mixing operation step: feeding the undersize fine particle pulp and the magnetic tailing pulp products into a thickening pump sump to obtain pre-thickening mixed slurry; The thickening operation step: feeding the pre-thickening mixed slurry in the thickening pump sump into a thickener for thickening operations to obtain thickened ore pulp products, and feeding them into a hydrocyclone pump sump; The grinding operation step: feeding the intermediate ore in path B into a grinding mill, mixing it with the products inside the grinding mill and performing grinding operations to obtain grinding products, and feeding them into the hydrocyclone pump sump, mixing with the thickened ore pulp products to obtain grinding pulp; The classification operation step: transporting the grinding pulp in the hydrocyclone pump sump to a hydrocyclone for classification operations. After the classification operations, classification overflow products and classification underflow products are obtained, and the classification underflow products are fed into the grinding mill for grinding operations again to obtain grinding products, and then fed into the hydrocyclone pump sump to be transported to the hydrocyclone again for classification operations, forming a closed-circuit grinding cycle operation.

2. The closed-circuit grinding method for middlings based on lithium ore according to claim 1, wherein It further includes the following steps: The concentrate treatment step: transporting the classification overflow products to a pulp de-sliming and sand-settling ore dressing system for pulp de-sliming and sand-settling operations and flotation dehydration ore dressing operations to obtain lithium concentrate and beryllium concentrate.

3. The method for closed-circuit grinding of intermediate ore based on lithium ore according to claim 1 or 2, characterized in that feeding the intermediate ore in path A into a heavy medium sizing screen through a first conveyor for screening operations; feeding the oversize large particle products into a heavy medium treatment system through a second conveyor for heavy medium separation operations; feeding the intermediate ore in path B into a grinding mill through a third conveyor for grinding operations.

4. The method for closed-circuit grinding of intermediate ore based on lithium ore according to claim 3, characterized in that the first conveyor, the second conveyor and / or the third conveyor is a belt conveyor.

5. The method for closed-circuit grinding of intermediate ore based on lithium ore according to claim 1 or 2, characterized in that the grinding mill is a wet overflow type ball mill.

6. A closed-circuit grinding system for intermediate ore based on lithium ore, characterized in that, It includes: a crushing and screening module for subjecting lithium ore to crushing and screening operations to obtain intermediate ore, which is divided into two paths, namely path A and path B; a heavy medium sizing screen operation module for feeding the intermediate ore in path A and water into a heavy medium sizing screen for screening operations to obtain undersize fine particle pulp and oversize large particle products, and subjecting the oversize large particle products to heavy medium separation operations to obtain magnetic tailing pulp products; a mixing operation module for feeding the undersize fine particle pulp and the magnetic tailing pulp products into a thickening pump sump to obtain pre-thickening mixed slurry; a thickening operation module for feeding the pre-thickening mixed slurry in the thickening pump sump into a thickener for thickening operations to obtain thickened ore pulp products, and feeding them into a hydrocyclone pump sump; The grinding operation module is used to feed the middlings in Route B into a grinding mill, mix them with the products inside the grinding mill and perform a grinding operation to obtain ground products, and then feed them into a hydrocyclone pump sump to obtain ground pulp. The classification operation module is used to transport the ground pulp in the hydrocyclone pump sump to a hydrocyclone for classification operation. After the classification operation, classified overflow products and classified underflow products are obtained, and the classified underflow products are fed into the grinding mill for grinding operation again to obtain ground products, and then fed into the hydrocyclone pump sump again to be transported to the hydrocyclone for classification operation again, forming a closed-circuit grinding cycle operation.

7. The closed-circuit grinding system for middlings based on lithium ore according to claim 6, characterized in that It further includes: The concentrate treatment module is used to transport the classified overflow products to a pulp desliming and sand-settling ore dressing system for pulp desliming and sand-settling operations and flotation dehydration ore dressing operations to obtain lithium concentrate and beryllium concentrate.

8. The closed-circuit grinding system for middlings of lithium ore according to claim 6 or 7, characterized in that The middlings in Route A are fed into a heavy medium sizing screen through a first conveyor for sizing operation; The oversized products on the screen are fed into a heavy medium treatment system through a second conveyor for heavy medium separation operation; The middlings in Route B are fed into a grinding mill through a third conveyor for grinding operation.

9. The closed-circuit grinding system for middlings of lithium ore according to claim 8, characterized in that The first conveyor, the second conveyor and / or the third conveyor is a belt conveyor.

10. The closed-circuit grinding system for middlings based on lithium ore according to claim 6 or 7, characterized in that, The grinding mill is a wet overflow type ball mill.

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