A harmless treatment system and method for phosphorus tailings

Abstract

The present invention provides a harmless treatment system for phosphorus tailings, comprising: a feed bin, a conditioning modifier stirring tank, a mixture stirring tank, a plate and frame filter press, and a disintegrator. The present invention also provides a harmless treatment method for phosphorus tailings. The harmless treatment system and method provided by the present invention can produce high-quality phosphorus tailings, solve the problems of water control of traditional phosphorus tailings with high water content (15% - 17%), easy secondary aggregation during stacking, high soluble phosphorus and fluorine contents, difficulty in fully mixing with cement or other cementitious materials during application, resulting in non-uniformity and corresponding strength loss of the solidified body, etc. The complete set of equipment system has a compact structure, high harmless treatment efficiency, good water control effect, and strong practicability.

Description

Technical Field

[0001] The present invention relates to the technical field of waste recycling and reuse, and particularly to a harmless treatment system and method for phosphorus tailings. Background Art

[0002] Phosphorus tailings mainly come from the tailings slag remaining after the flotation of phosphate ore, belonging to mining solid waste among industrial solid wastes. Phosphorus tailings are not suitable for direct use as building fillers because they are acidic, with high contents of water-soluble harmful ions such as phosphorus and fluorine, which will affect the hydration process of cement. At the same time, traditional phosphorus tailings have a high water content (15% - 17%), making it difficult to feed during use and prone to agglomeration during stacking; and in the flotation process, due to the addition of flotation reagents, mutual adsorption will occur between the particles of the phosphorus tailings filter cake. Even after being dispersed by a dispersing machine, secondary agglomeration will occur during the stacking process. It is difficult to fully mix the agglomerated phosphorus tailings with cement or other cementitious materials, resulting in problems such as non-uniformity of the cementitious structure body and strength loss of the corresponding solidified body, affecting the strength of building materials and unable to meet the quality requirements of building materials.

[0003] Therefore, when using phosphorus tailings as building fillers, the following pain points must be solved first: the ion leachate of phosphorus tailings must meet the first-class standard for solid waste; reduce the water content of phosphorus tailings to achieve water control of the filter cake; use a conditioning modifier to change the surface electrochemical characteristics of phosphorus tailings, reduce the mutual adsorption between the surfaces of phosphorus tailings filter cake particles, so that after the phosphorus tailings are dispersed, no secondary agglomeration will occur; select a suitable dispersing device to solve the pain point of difficult dispersion of high-water-content filter cake.

[0004] In the comprehensive utilization research of phosphorus tailings, there are already methods for harmless treatment of phosphorus tailings with calcined raw materials and an application of geopolymers for stabilizing the roadbed of phosphorus tailings. For example, Chinese Patent with publication number CN112934906A discloses a method for harmless treatment of phosphorus tailings and phosphogypsum with calcined raw materials. Its main feature is to select calcined raw materials as treatment agents, and through a batching device, transport the calcined raw materials, phosphorus tailings, and phosphogypsum to a stirring and mixing device, mix them evenly and then transport them to a slag yard for stacking. However, the production of each material through a dry mixing and stirring and mixing device has disadvantages such as slow reaction speed, long harmless treatment time, uneven and incomplete harmless treatment, and many agglomerated particles affecting the performance of building materials.

[0005] For another example, a Chinese patent with the publication number CN113548843A discloses a geopolymer-stabilized phosphorus tailings roadbase and its preparation method. In the geopolymer-stabilized phosphorus tailings roadbase, it is prepared from 6-20 wt% of carbide slag, 15-24 wt% of one or both of phosphorus slag powder and fly ash, and 60-70 wt% of phosphorus tailings. This application also provides a preparation method of the geopolymer-stabilized phosphorus tailings roadbase. The roadbase forms an alkaline environment through the dissolution and ionization of the main component Ca(OH) of the carbide slag, providing conditions for the breakage of the silicon-oxygen bond in the phosphorus slag powder or fly ash, and recombining to generate geopolymer gels such as calcium silicate hydrate (C-S-H) and calcium aluminate hydrate (C-A-H). The geopolymer gels cement between the phosphorus tailings particles, and then solidify and interlock with each other to form a rigid matrix with mechanical strength, building the mechanical properties and durability of the roadbase. However, this invention does not have a front-end treatment process for phosphorus tailings. When phosphorus tailings are applied in the roadbase, there are problems such as high water content, easy caking during mixing, and difficulty in controlling the moisture of construction materials. At the same time, without tempering and modification, the phosphorus tailings after being dispersed are prone to secondary agglomeration during stacking, and it is difficult to fully mix them with cement or other cementitious materials during application, resulting in unevenness and corresponding strength loss of the solidified body. 2 The dissolution and ionization of the main component Ca(OH) of the carbide slag form an alkaline environment, providing conditions for the breakage of the silicon-oxygen bond in the phosphorus slag powder or fly ash, and recombining to generate geopolymer gels such as calcium silicate hydrate (C-S-H) and calcium aluminate hydrate (C-A-H). The geopolymer gels cement between the phosphorus tailings particles, and then solidify and interlock with each other to form a rigid matrix with mechanical strength, building the mechanical properties and durability of the roadbase. However, this invention does not have a front-end treatment process for phosphorus tailings. When phosphorus tailings are applied in the roadbase, there are problems such as high water content, easy caking during mixing, and difficulty in controlling the moisture of construction materials. At the same time, without tempering and modification, the phosphorus tailings after being dispersed are prone to secondary agglomeration during stacking, and it is difficult to fully mix them with cement or other cementitious materials during application, resulting in unevenness and corresponding strength loss of the solidified body.

[0006] The harmless treatment of the traditional direct mixing method of phosphorus tailings is not thorough, uneven, and has a long reaction time. Moreover, it is impossible to use high water content or liquid alkaline tempering and modifying agents. After the phosphorus tailings are directly mixed with wet-based or dry-based tempering and modifying agents through a mixer and then stacked in a warehouse, not only is the harmless treatment uneven, the samples often exceed the standards, and the environmental protection risk is high. And it requires a long reaction time, generally requiring a stacking and storage time of more than 3 to 7 days, greatly reducing the use efficiency.

[0007] The dispersion treatment of high water content materials has always been a pain point and a difficult point. As a high water content material, phosphorus tailings are not only difficult to disperse, but also in the traditional beneficiation process, flotation, flocculation sedimentation, etc. are achieved by adding agents. After adding agents to the phosphorus tailings, the electrochemical characteristics of the surface of the phosphorus tailings will change, resulting in an adsorption effect between the phosphorus tailings filter cake particles. Even after being dispersed by a disperser, secondary agglomeration will still occur during stacking, affecting the unevenness caused by the difficulty of fully mixing with cement or other cementitious materials during subsequent application and the corresponding strength loss of the solidified body. Summary of the Invention

[0008] The technical problem solved by the present invention is to provide a harmless treatment system for phosphorus tailings, which can make the particle size of phosphorus tailings meet the particle size requirements for building materials.

[0009] In view of this, the present application provides a harmless treatment system for phosphorus tailings, including: a feed bin, a conditioning modifier mixing tank, a mixture mixing tank, a plate and frame filter press, and a disintegrator;

[0010] The outlet of the feed bin is connected to the inlet of the conditioning modifier mixing tank;

[0011] The outlet of the conditioning modifier mixing tank is connected to the first inlet of the mixture mixing tank;

[0012] The outlet of the mixture mixing tank is connected to the inlet of the plate and frame filter press;

[0013] The first outlet of the plate and frame filter press is connected to the inlet of the disintegrator;

[0014] The inlet of the conditioning modifier mixing tank is also connected to the outlet of a high-level water tank;

[0015] The second inlet of the mixture mixing tank is also connected to the outlet of a thickened phosphorus tailings slurry tank;

[0016] The second outlet of the plate and frame filter press is connected to the third inlet of the mixture mixing paddle.

[0017] Preferably, a flow meter is provided between the high-level water tank and the conditioning modifier mixing tank; a slurry pump and a flow meter are provided between the conditioning modifier mixing tank and the mixture mixing tank.

[0018] Preferably, a flow meter is provided between the thickened phosphorus tailings slurry tank and the mixture mixing tank, a slurry pump is provided between the mixture mixing tank and the plate and frame filter press, and a pH meter is provided between the plate and frame filter press and the mixture mixing tank.

[0019] Preferably, the conditioning modifier mixing tank is a single-shaft horizontal paddle mixing tank, the mixture mixing tank is a double-shaft horizontal paddle mixing tank, the plate and frame filter press is a water-washed plate and frame filter press, and the disintegrator is a rotary screen bar type flying knife disintegrator.

[0020] Preferably, it further includes a finished product storage yard, which is arranged below the disintegrator.

[0021] The present application also provides a method for treating phosphorus tailings by the harmless treatment system according to claim 1, including the following steps:

[0022] Mix the conditioning modifier and water to obtain a conditioning modifier slurry;

[0023] Mix the conditioning modifier slurry and the thickened phosphorus tailings slurry to obtain a mixture slurry;

[0024] Filter press the mixture slurry to obtain a phosphorus tailing filter cake;

[0025] Break up the phosphorus tailing filter cake and then age it.

[0026] Preferably, the method further includes:

[0027] After pH detection of the filtrate after filter pressing, adjust the pH of the thickened phosphorus tailing slurry.

[0028] Preferably, the conditioning modifier is selected from one or two of carbide slag, water treatment slag, and other wet-based or liquid alkaline conditioning modifiers.

[0029] Preferably, the water treatment slag is alkaline water treatment slag, which includes: P 2 O 5 : 9-16 wt%, fluoride: 0.2-0.5 wt%, CaO: 50-60 wt%, MgO: 9-12 wt%, SO 3 : 2-4 wt%, Al 2 O 3 : 0.5-1 wt%, Fe 2 O 3 : 0.2-0.4 wt%; or, the alkaline water treatment slag includes primary precipitation water treatment slag and secondary precipitation water treatment slag. The pH of the primary precipitation water treatment slag > 11, and the primary precipitation water treatment slag is directly used as the conditioning modifier. The pH of the secondary precipitation water treatment slag is 10-11, and the secondary precipitation water treatment slag needs to be used together with carbide slag with a dry basis mass ratio of 0.2-1% in the thickened phosphorus tailing slurry as the conditioning modifier, pH > 11; the specific gravity of the thickened phosphorus tailing slurry is 1.5-1.7, and the residual flocculant concentration is 0.6-3.0 mg / L; the particle size of the phosphorus tailing is 0-200 μm, and the main chemical components are CaO: 25-40 wt%, MgO: 10-20 wt%, SiO 2 : 1-4 wt%, fluoride: 0.99 wt%, P 2 O 5 : 4-10 wt%, SO 3 : 0.1-0.4 wt%, Fe 2 O 3 : 0.1-0.4 wt%, with dolomite as the main component.

[0030] Preferably, the water treatment slag is a liquid slurry with a specific gravity of 1.05-1.10 or a filter cake with a moisture content of 20-30% after filter pressing of the water treatment slag. The carbide slag includes Ca(OH) 2 , with a moisture content of 20-30%.

[0031] Preferably, the specific gravity of the mixed slurry is 1.4 - 1.6, and the pH is 9.0 - 12.0.

[0032] Preferably, the moisture content of the phosphorus tailing filter cake is 8 - 11%, the average particle size of the dispersed phosphorus tailings is 0.5 - 3 mm, and the aging time is 8 - 12 h.

[0033] The present application provides a harmless treatment system for phosphorus tailings, which includes a feed bin, a conditioning modifier stirring tank, a mixed material stirring tank, a plate and frame filter press, and a dispersing machine; in the harmless treatment system provided by the present application, by introducing a feed bin and a conditioning modifier stirring tank, the addition of wet-based or liquid alkaline conditioning modifiers can be realized, the slurry concentration of the conditioning modifier, the specific gravity of the mixed slurry, and the pH value of the filter press filtrate can be controlled, and the conditioning modifier can be stably and evenly mixed with the thickened phosphorus tailings slurry. The water washing function of the phosphorus tailing filter cake can be realized through the plate and frame filter press, and the filter cake can be dispersed to meet the particle size requirements for building materials through the dispersing machine.

[0034] Furthermore, the present application also provides a harmless treatment method for phosphorus tailings, which changes the surface electrochemical properties of phosphorus tailings by using a conditioning modifier, reduces the mutual adsorption between the surfaces of phosphorus tailing filter cake particles, so that after the phosphorus tailings are dispersed, no secondary agglomeration phenomenon will occur; at the same time, the use of the conditioning modifier reduces the content of water-soluble phosphorus and fluoride ions in the phosphorus tailings.

[0035] Furthermore, by regulating the specific gravity and pH of the phosphorus tailings mixed slurry, the present application reduces the moisture content of the phosphorus tailings to 8 - 11%, realizes the water control function of the phosphorus tailings, solves the problems of easy secondary agglomeration during stacking, high soluble phosphorus and fluoride contents, and the difficulties such as unevenness caused by the difficulty of fully mixing with cement or other gelling materials during application and the corresponding strength loss of the solidified body. The complete set of systems has a compact structure, high harmless treatment efficiency, good water control effect, and strong practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the device for the harmless treatment system of phosphorus tailings of the present invention;

[0037] Figure 2 It is a particle size distribution diagram of the water treatment slag used in the present invention;

[0038] Figure 3 It is a relationship curve diagram of pH and Zeta potential of the system formed by phosphorus tailings and flocculant of the present invention;

[0039] Figure 4 It is a schematic internal structure diagram of the dispersing machine used for the filter cake of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] To further understand the present invention, the preferred embodiments of the present invention will be described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0041] In view of the problems in the prior art that in the phosphorus tailings treatment method, the content of water-soluble phosphorus and fluoride ions is high, agglomeration and secondary agglomeration are likely to occur during the stacking process, and the particle size requirements for building materials cannot be met, the present application provides a harmless treatment system and method for phosphorus tailings, which enables the treated phosphorus tailings not to show secondary agglomeration phenomena, realizes the water control function, and the discharge particle size meets the requirements for the phosphorus tailings for the base layer to be broken up. Specifically, the present application first provides a harmless treatment system for phosphorus tailings, as Figure 1 shown Figure 1 In the figure, 1 is a feed bin, 2 is a metering belt, 3 is a conditioning modifier mixing tank, 4 is a high-level water tank, 5 is a flowmeter, 6 is a slurry pump, 7 is a flowmeter, 8 is a mixture mixing tank, 9 is a flowmeter, 10 is a slurry pump, 11 is a plate-and-frame filter press, 12 is a pH meter, 13 is a conveyor belt, 14 is a disintegrator. Specifically, the embodiment of the present invention discloses a harmless treatment system for phosphorus tailings, including: a feed bin, a conditioning modifier mixing tank, a mixture mixing tank, a plate-and-frame filter press, and a disintegrator;

[0042] The outlet of the feed bin is connected to the inlet of the conditioning modifier mixing tank;

[0043] The outlet of the conditioning modifier mixing tank is connected to the first inlet of the mixture mixing tank;

[0044] The outlet of the mixture mixing tank is connected to the inlet of the plate-and-frame filter press;

[0045] The first outlet of the plate-and-frame filter press is connected to the inlet of the disintegrator;

[0046] The inlet of the conditioning modifier mixing tank is also connected to the outlet of the high-level water tank;

[0047] The second inlet of the mixture mixing tank is also connected to the outlet of the thick phosphorus tailings slurry tank;

[0048] The second outlet of the plate-and-frame filter press is connected to the third inlet of the mixture mixing paddle.

[0049] In the harmless treatment system for phosphorus tailings provided by this application, a flow meter is arranged between the elevated water tank and the conditioning modifier stirring tank, and the flow meter is used to adjust the water addition amount in the elevated water tank. A slurry pump and a flow meter are arranged between the conditioning modifier stirring tank and the mixture stirring tank. A slurry pump is arranged between the mixture stirring tank and the plate-and-frame filter press. A pH meter is arranged between the plate-and-frame filter press and the mixture stirring tank. The pH meter monitors the pH of the filtrate in the filter press, and the filtrate of the plate-and-frame filter press is fed into the mixture stirring tank for recycling.

[0050] In this application, the conditioning modifier stirring tank is a single-shaft horizontal paddle stirring tank, the mixture stirring tank is a double-shaft horizontal paddle stirring tank, the plate-and-frame filter press is a water-washing type plate-and-frame filter press, and the disintegrator is a rotary sieve bar type flying knife disintegrator, with an average disintegration particle size of 0.5 - 3 mm.

[0051] The rotary flying knife type disintegration equipment for phosphorus tailings filter cake includes two similar mainstream disintegration equipment, namely the disintegration feeder and the honeycomb mill. At the same time, the rotary flying knife disintegrator is divided into two types: the impact throwing type flying knife and the sieve bar type flying knife. When non-metallic minerals such as kaolin, quartz, and heavy calcium carbonate are wet ultrafinely processed, the powder that has reached the product fineness requirement will re-aggregate to form pseudo-particles after spray drying or calcination. If not eliminated, it will affect the particle size and use of the final product. At this time, it is often necessary to depolymerize and disintegrate. For this situation, the honeycomb mill (abbreviated as CM) is the most mainstream disintegration equipment. This type of disintegrator has relatively high requirements for the particle size of the incoming material. When the phosphorus tailings have been stored for a long time and the particles formed after aggregation are relatively large, it affects the feeding, and it is not easy to clean after jamming the material. Therefore, this type of disintegrator is not recommended.

[0052] Whether it is the most mainstream disintegration equipment such as the honeycomb mill or the disintegration feeder, they cannot meet the requirements when applied to the disintegration of phosphorus tailings filter cake. For the compact particles with strong binding force formed by phosphorus tailings, the use of high-speed flying knife disintegration equipment has better functions. The flying knife disintegrator is mainly divided into two types according to the dry and wet degree of the material used. One is to disperse the particles by the high-speed impact throwing blades of the rotor, which is mainly applicable to materials with a moisture content of less than 8%. If the moisture content is too high, the material will agglomerate on the inner layer of the shell; the other is the sieve bar type flying knife. Multiple flying knives are arranged along the shell, avoiding the agglomeration of high-viscosity materials on the shell, and by adjusting the position of the blades, the gap between the blades and the lining plate is reduced, so that a satisfactory particle size can be obtained.

[0053] When the water content of phosphorus tailings is relatively high, it is not suitable to choose the impact throwing type flying knife. The sieve bar type flying knife can avoid this problem. The feeding particle size of the sieve bar type equipment is ≤150 mm, and the discharging particle size is ≤3 mm (about 90% or more is below 2 mm). From the perspective of the disintegration effect of phosphorus tailings, the discharging particle size can meet the requirements for the disintegration of phosphorus tailings used in the base course.

[0054] The harmless treatment system described in this application further includes a finished product yard, which is arranged below the disintegrator, and the storage capacity of the finished product yard is greater than or equal to the production volume of the set filter cake for 1 to 3 days.

[0055] Specifically, the liquid-phase harmless treatment system for phosphorus tailings in this application is provided with a feed bin (1) for containing the conditioning modifier. A metering belt (2) is arranged at the lower part of the feed bin (1) and is connected to a conditioning modifier stirring tank (3). A high-level water tank (4) is arranged above the conditioning modifier stirring tank (3). The high-level water tank (4) adds water and the conditioning modifier in a fixed ratio to the conditioning modifier stirring tank (3) for stirring and mixing through a flow meter (5), so that the concentration of the conditioning modifier slurry in the conditioning modifier stirring tank (3) is the set value. The conditioning modifier slurry tank (3) is provided with a slurry pump (6) and a flow meter (7) and is connected to a mixture stirring tank (8). The thick phosphorus tailings slurry connected to the mixture stirring tank (8) is mixed and stirred in a set ratio through a flow meter (9). The mixture stirring tank (8) is provided with a slurry pump (10) and is connected to a plate-and-frame filter press (11). A pH measuring instrument (12) is arranged at the filtrate pipeline of the plate-and-frame filter press (11) to monitor the pH of the filtrate. The filtrate of the plate-and-frame filter press (11) is introduced into the mixture stirring tank for recycling. The plate-and-frame filter press (11) is connected to a rotary flying knife disintegrator (14) through a conveyor belt (13) below for disintegration, and a finished product yard (15) is arranged below the rotary flying knife disintegrator (14).

[0056] Specifically, this application also provides a method for treating phosphorus tailings by a harmless treatment system, including the following steps:

[0057] Mix the conditioning modifier and water to obtain a conditioning modifier slurry;

[0058] Mix the conditioning modifier slurry and the thick phosphorus tailings slurry to obtain a mixture slurry;

[0059] Filter press the mixture slurry to obtain a phosphorus tailings filter cake;

[0060] Disintegrate and age the phosphorus tailings filter cake.

[0061] In the process of specifically treating phosphorus tailings, the treatment process using the treatment system for phosphorus tailings is as follows:

[0062] The liquid conditioning modifier is directly added to the conditioning modifier slurry mixing tank (3). The conditioning modifier slurry is metered by a slurry pump (6) and a flow meter (7), and after being metered by a flow meter (9), it is mixed with the thickened phosphorus tailings slurry in a mixing ratio in the mixing material mixing tank (8) to obtain a mixed slurry. The mixed slurry enters a plate and frame filter press (11) through a slurry pump (10). The filtrate of the plate and frame filter press (11) can feedback and adjust the pH value of the slurry after being detected by a pH meter (12). The filter cake of the plate and frame filter press (11) is connected to a rotary flying knife disintegrator (14) through a conveyor belt (13) below for disintegration. The disintegrated filter cake at the outlet of the rotary flying knife disintegrator falls into the finished product yard (15) for post - curing reaction, and users can store it for 8 - 12 hours.

[0063] More specifically, the wet - based conditioning modifier is poured into the silo (1), and the conditioning modifier then enters the metering belt (2) and thus enters the conditioning modifier mixing tank (3). Then, the water in the elevated water tank (4) is metered by a flow meter (5) and enters the conditioning modifier slurry mixing tank (3) to be mixed with the conditioning modifier to form a conditioning modifier slurry with a fixed concentration. The conditioning modifier slurry is metered by a slurry pump (6) and a flow meter (7), and after being metered by a flow meter (9), it enters the mixing material mixing tank (8) in a set ratio to obtain a mixed slurry. The mixed slurry enters a plate and frame filter press (11) through a slurry pump (10) to obtain filtrate and filter cake. The filtrate obtained from the plate and frame filter press (11) can feedback and adjust the pH value of the mixed slurry after being detected by a pH meter (12). The filter cake of the plate and frame filter press (11) is connected to a rotary flying knife disintegrator (14) through a conveyor belt (13) below for disintegration. The disintegrated filter cake at the outlet of the rotary flying knife disintegrator falls into the finished product yard (15) for post - curing reaction, and users can store it for 8 - 12 hours.

[0064] In this application, the thickened phosphorus tailings slurry is subjected to conditioning and modification treatment; the specific gravity of the thickened phosphorus tailings slurry is 1.5 - 1.7, and the residual flocculant concentration is 0.6 - 3.0 mg / L; the particle size of the phosphorus tailings is 0 - 200 μm, and the main chemical components are CaO: 25 - 40 wt%, MgO: 10 - 20 wt%, SiO 2 : 1 - 4 wt%, fluoride: 0.99 wt%, P 2 O 5 : 4 - 10 wt%, SO 3 : 0.1 - 0.4 wt%, Fe 2 O 3 : 0.1 - 0.4 wt%, with dolomite as the main component. The conditioning modifier is selected from one or two of carbide slag, water treatment slag, and other wet - based or liquid alkaline conditioning modifiers; among them, the alkaline water treatment slag includes: P 2 O 5: 9 - 16 wt%, fluoride: 0.2 - 0.5 wt%, CaO: 50 - 60 wt%, MgO: 9 - 12 wt%, SO 3 : 2 - 4 wt%, Al 2 O 3 : 0.5 - 1 wt%, Fe 2 O 3 : 0.2 - 0.4 wt%; or, the alkaline water treatment slag includes primary precipitation water treatment slag and secondary precipitation water treatment slag, the pH of the primary precipitation water treatment slag > 11, the primary precipitation water treatment slag is directly used as a conditioning and modification agent, the pH of the secondary precipitation water treatment slag is 10 - 11, and the secondary precipitation water treatment slag and carbide slag with a dry basis mass ratio of 0.2 - 1 wt% in the thickened phosphate tailings slurry are used together as a conditioning and modification agent, pH > 11.

[0065] The leaching characteristic indexes of the above conditioning and modification agent after harmless treatment of phosphate tailings are shown in Table 1 below;

[0066] Table 1 Data table of leaching characteristics of phosphate tailings before and after conditioning and modification

[0067]

[0068] Note: "Not detected" represents not detected; in the table, only the water treatment slag is the primary water treatment slag, and carbide slag and secondary water treatment slag are used in combination.

[0069] From the above experimental results, it can be seen that the addition of water treatment slag can effectively reduce the content of soluble phosphorus, fluorine, etc. in phosphate tailings. Among them, the primary water treatment slag can fully meet the requirements of the conditioning and modification agent, and control the content of soluble phosphorus, fluorine, etc. within the first-class standard of solid waste; although the addition of the secondary water treatment slag can greatly reduce the content of soluble phosphorus and fluorine, it still lacks to meet the first-class standard of solid waste, unless it is incorporated in multiples, but the consequent result is that the moisture content of the phosphate tailings filter cake rises sharply. When 0.2 - 1.0% of carbide slag based on the total dry basis mass of the mixed slurry is added and used in combination, the content of soluble phosphorus, fluorine, etc. can be effectively controlled within the first-class standard of solid waste. The main principle is: when the pH of the phosphate tailings mixed slurry is greater than 10, the soluble phosphorus in the phosphate tailings mixed slurry mainly exists in the forms of HPO 4 2- , PO 4 2 -, and reacts with Ca 2+ to generate CaHPO 4 , Ca 3 (PO 4 ) 2 precipitate. Its solubility is low and it is difficult to dissolve with a small ionization degree. Therefore, it can effectively solidify the soluble phosphorus; the soluble fluorine mainly exists in the form of F -exists in the form that when the pH is greater than 10, Ca 2+ can effectively remove F - for solidification, and at the same time can release OH - , increasing the alkaline environment and accelerating the neutralization and solidification of acidic substances in phosphorus tailings; thus, it can effectively solidify soluble phosphorus and soluble fluorine, and the leachate of phosphorus tailings can even reach the third-class standard of surface water; when the pH is less than 10, soluble phosphorus mainly exists in the form of H 2 PO 4 - , which reacts with Ca 2+ to form Ca(H 2 PO 4 ) 2 precipitate, which is easy to hydrolyze and ionize.

[0070] Moreover, in this application, the phosphorus tailings are treated by tempering and modification, and the leaching toxicity of the phosphorus tailings can also be regulated. Phosphorus tailings with leaching toxicity meeting the requirements of the first-class standard of solid waste can be obtained, as shown in Table 1. It can be seen from the table that when 20% of water treatment slag is incorporated into the phosphorus tailings slurry, the content of soluble phosphorus in the phosphorus tailings can be greatly reduced. When used in combination with 0.5% of carbide slag, phosphorus tailings meeting the first-class standard of solid waste can be obtained after the filter cake is stored for 8 hours. The water treatment slag of the present invention can be used in a large amount, realizing the unified discharge and utilization of solid waste.

[0071] In this application, a tempering and modification agent is used to treat the phosphorus tailings, and water treatment slag is preferably added. However, the uncontrolled and inaccurately metered incorporation of water treatment slag and the unconscious regulation of the specific gravity of the phosphorus tailings slurry result in the specific gravity of the phosphorus tailings slurry being lower than 1.3 for a long time. And the large amount of incorporation of water treatment slag will cause the moisture content to increase sharply, resulting in a sharp decline in the pressure filtration performance, and the moisture content of the phosphorus tailings filter cake is very high, remaining at 15-17% for a long time. The main reasons are as follows: First, the concentration of water treatment slag is low, and after a large amount of incorporation, the concentration of the mixed slurry will be too low, making it difficult to filter; Second, the particle size of water treatment slag is too fine compared with that of phosphorus tailings (the average particle size of phosphorus tailings is 74um, and the specific surface area is 354m 2 / kg), and the filtration effect is not good compared with that of phosphorus tailings. The particle size distribution of water treatment slag is shown in Figure 2 .

[0072] In the implementation process of the present invention, by precisely controlling the mixing ratio of raw materials and gradually increasing the specific gravity and pH of the mixed slurry in the mixing tank of the mixture, the regulation of phosphorus tailings with high moisture content can be achieved, as shown in Table 2 and Table 3 below;

[0073] Table 2 Data table of the influence of the specific gravity of the mixed slurry on the pressure filtration performance

[0074]

[0075] Note: "Not detected" means not detected; the first-level water treatment slag is the only one in the table, and the carbide slag and the second-level water treatment slag are used in combination.

[0076] Table 3 Data table of the influence of the pH of the mixed slurry on the pressure filtration performance

[0077] Number Slurry pH Slurry specific gravity Average moisture content of phosphorous tailings filter cake % 3-1 6-7 1.34 13.07 3-2 10-11 1.34 10.10 3-3 12-13 1.34 10.01

[0078] As can be seen from Table 2 and Table 3, when the slurry specific gravity rises to 1.51, the moisture content of the phosphorus tailings filter cake produced at this time is 9.10%. As the specific gravity of the phosphorus tailings mixed slurry decreases, the moisture content of the filter cake gradually increases. At the same time, when controlling the slurry specific gravity and other parameters of the pressure filtration device unchanged, as the pH of the slurry gradually increases, the moisture content of the filter cake first decreases and then basically remains unchanged.

[0079] In view of the above analysis, the applicant believes that the slurry specific gravity and pH of the mixed slurry have an important impact on the treatment of phosphorus tailings. The following is a specific description:

[0080] (1) Influence of slurry specific gravity on pressure filtration performance

[0081] The main principle is that when the concentration value of the mixed slurry is low, fine particles are very easy to directly enter the filter cloth pores, cross over, block or cover them, and quickly block the pores of the filtering substance. As the slurry concentration value increases, a large number of particles will approach or reach the pores of the filtering substance. Due to mutual influence, most particles cannot enter the pores, but arch on it as a road bridge, so that the filter pores can not be severely blocked for a long time.

[0082] (2) Influence of pH (Ca(OH) content in the mixed slurry) on pressure filtration performance 2

[0083] In addition to the influence of specific gravity on pressure filtration performance, when the water treatment slag or the combination of water treatment slag and carbide slag is added to the thickened phosphorus tailings slurry, in an alkaline environment, a large amount of Ca(OH) 2 solids are generated, separating the negatively charged flocculant from the phosphorus tailings particles, adsorbing to form extracellular flocs, and forming an extracellular flocculant composed of a porous network-like skeleton composite, providing a channel for water, thereby improving the dehydration ability.

[0084] In the flotation process, after the conditioning modifier of the present invention is added, the extracellular flocs in the phosphorus tailings are porous network-like skeletons, and the produced phosphorus tailings are more dispersed than the original phosphorus tailings.

[0085] (3) Influence of pH value (OH content in the mixed slurry) on the agglomeration of phosphorus tailings -

[0086] Phosphorus tailings are industrial solid wastes by-produced after the flotation of phosphate ore. In traditional phosphate ore flotation processes, a large amount of flocculant is added to thicken the dilute slurry of phosphorus tailings, resulting in the phosphorus tailings filter cake being in a caked state after production. Even after being broken up, secondary agglomeration will occur.

[0087] To improve the agglomeration phenomenon of phosphorus tailings, it is necessary to improve their surface electrochemical properties, and try to increase the repulsive force of the surface charge of the particles, so that there is no adhesion between particles and between particles and extracellular flocs. Therefore, the influence of the addition of the front-end flocculant on the adhesion properties of the phosphorus tailings filter cake and the influence of the pH regulation after the addition of the conditioning modifier on the adhesion properties of the phosphorus tailings filter cake were verified. As follows:

[0088] As the concentration of the flocculant increases, the absolute value of the Zeta potential on the surface of the phosphorus tailings shows a decreasing trend, and finally the Zeta potential reaches an equilibrium state (as Figure 3 shown). The flocculant used is non-ionic. Due to the relatively large molecular weight of the flocculant, after being dissolved in deionized water, the polymer chain has a strong adsorption bridging ability, which enables the phosphorus tailings particles to be quickly connected and aggregated. The flocculant has the effect of compressing the double electric layer, resulting in a decrease in the potential and a downward trend in the Zeta potential.

[0089] The zero potential point of the Zeta potential of the phosphorus tailings appears when the pH value is 5-7. After treatment with the flocculant, the zero potential point of the Zeta potential of the phosphorus tailings appears when the pH value is 7-9 (as Figure 4 shown). The non-ionic flocculant mainly interacts with the surface of the fine phosphorus tailings particles through the "adsorption bridging effect", compressing the surface double layer and reducing the absolute value of the Zeta potential on the surface of the phosphorus tailings. When the pH increases to 9-13, the absolute value of the Zeta potential on the surface of the phosphorus tailings particles increases significantly, indicating that the thickness of the double electric layer increases under alkaline conditions, which can destroy the adsorption of the flocculant on the surface of the phosphorus tailings particles.

[0090] It can be seen from this that conditioning and modification at a pH of 9-13 for the mixed slurry can reduce the mutual adsorption effect between the particles of the phosphorus tailings filter cake caused by the addition of the front-end flotation process agent (flocculant), and avoid the problem of secondary agglomeration when the filter cake is broken up.

[0091] In this application, the mixed slurry is pressure-filtered to obtain a phosphorus tailing filter cake, and then the filter cake obtained by pressure filtration is dispersed. During the above process, the moisture content of the filter cake is 8-11%, and the average particle size of the dispersed phosphorus tailings is 0.5-3 mm. For the compact particles with strong binding force formed by phosphorus tailings, the use of a high-speed flying knife dispersion device has good functionality. Among the flying knife type dispersion devices, the sieve bar type flying knives are arranged along the shell, which avoids the agglomeration of high-viscosity materials on the shell plate. And by adjusting the position of the blades to reduce the gap with the lining plate, a satisfactory particle size can be obtained. The feeding particle size of the sieve bar type device is ≤150 mm, and the discharging particle size is ≤3 mm (about 90% or more is below 2 mm). From the effect of dispersing phosphorus tailings using an experimental machine, the discharging particle size can meet the requirements of dispersing phosphorus tailings for the base course.

[0092] Finally, the dispersed phosphorus tailings in this application are aged, and the aging time is 8-12 h.

[0093] The present invention discloses a complete set of equipment system and process control method for the harmless treatment of phosphorus tailings, which is prepared by mixing a tempering modifier and phosphorus tailings in a certain mass ratio to form a mixed slurry, passing through a liquid-phase harmless treatment device, a pressure filtration device, a dispersion device, and performing a post-treatment aging reaction in a finished product yard. The present invention mixes the tempering modifier and the thickened phosphorus tailings slurry in a set ratio until the specific gravity of the mixed slurry reaches 1.40-1.60 and the filtrate water reaches the set pH value of 10-12. The mixed slurry is pressure-filtered through a plate-and-frame pressure filtration device, and the filtrate water here enters the mixed material stirring tank for recycling. The free moisture content in the obtained filter cake is 8-11%; the dispersion device is used to disperse the phosphorus tailing filter cake, and a rotating flying knife is used for dispersion here, and the average particle size of the obtained phosphorus tailings can reach 0.5-3 mm; the finally dispersed harmless phosphorus tailings are sent to the finished product yard by belt for post-treatment aging reaction, and the reaction time here is 8-12 h. The present invention can produce high-quality phosphorus tailings, and can solve the problems of water control of traditional phosphorus tailings with high water content (15%-17%), easy secondary agglomeration during stacking, high soluble phosphorus and fluorine content, difficulty in fully mixing with cement or other cementitious materials during application, resulting in non-uniformity and corresponding strength loss of the cured body, etc. The complete set of equipment system has a compact structure, high harmless treatment efficiency, good water control effect, and strong practicability.

[0094] To further understand the present invention, the following examples are used to detail the harmless treatment system and method of phosphorus tailings provided by the present invention. The protection scope of the present invention is not limited by the following examples.

[0095] Example 1

[0096] As Figure 1As shown in the figure, the liquid-phase harmless treatment system for phosphorus tailings is provided with a feed bin (1) for containing the conditioning modifier. A metering belt (2) is provided at the lower part of the feed bin (1) and is connected to a conditioning modifier mixing tank (3). A high-level water tank (4) is provided above the conditioning modifier mixing tank (3). The high-level water tank (4) measures and adds water in a fixed ratio to the conditioning modifier in the conditioning modifier mixing tank (3) through a flow meter (5) for stirring and mixing, so that the concentration of the conditioning modifier slurry in the conditioning modifier mixing tank (3) is the set value concentration. The conditioning modifier slurry tank (3) is provided with a slurry pump (6) and a flow meter (7) which are connected to a mixture stirring tank (8). The thick phosphorus tailings slurry connected to the mixture stirring tank (8) is mixed and stirred with the conditioning modifier slurry in the mixture stirring tank (8) according to a set ratio through a flow meter (9). The mixture stirring tank (8) is provided with a slurry pump (10) which is connected to a plate and frame filter press (11). A pH meter (12) is provided at the filtrate pipeline of the plate and frame filter press (11) to monitor the pH of the filtrate. The filtrate of the plate and frame filter press (11) is fed into the mixture stirring tank for recycling. The plate and frame filter press (11) is connected to a rotary flying knife disintegrator (14) through a conveyor belt (13) below for disintegration. A finished product yard (15) is provided below the rotary flying knife disintegrator (14).

[0097] Example 2

[0098] Based on the equipment in Example 1, carbide slag, the water treatment slag slurry produced by the water treatment station of Guizhou Chuanheng Chemical Co., Ltd., and the thick phosphorus tailings slurry discharged from the flotation workshop are fed in according to the dry basis ratio of carbide slag: water treatment slag: tailings = 0.7:20:79.3. The carbide slag and the water treatment slag slurry are first stirred evenly in the conditioning modifier mixing tank according to the dry basis ratio of carbide slag: water treatment slag = 0.7:20, and then are transported to the mixture slurry stirring tank according to a ratio through a flow meter and mixed evenly with the thick phosphorus tailings slurry. The mixture slurry is filtered by a filter press. During continuous production, the dosage of carbide slag and water treatment slag is adjusted by monitoring the pH value and specific gravity of the filtrate water of the mixture slurry. The water treatment slag is secondary alkaline water treatment slag with a specific gravity of 1.08 and a pH of 11. Its main chemical components include: P 2 O 5 : 15 wt%, fluoride: 0.2 wt%, CaO: 55 wt%, MgO: 10 wt%, SO 3 : 4 wt%, Al 2 O 3 : 0.5 wt%, Fe 2 O 3 : 0.3 wt%; the carbide slag contains Ca(OH) 2 , the moisture content of the filter cake is 30%, and the main components are SiO 2 : 3 wt%, Al 2 O 3 : 0.9 wt%, CaO: 79 wt%, SO3 : 0.1 wt%, Fe 2 O 3 : 0.05 wt%; The specific gravity of the concentrated phosphorus tailings slurry is 1.6, the concentration of the residual flocculant is 2.5 mg / L, the particle size of the phosphorus tailings is 150 - 180 um, and the main chemical components are CaO: 40 wt%, MgO: 20 wt%, SiO 2 : 4 wt%, fluoride 0.99 wt%, P 2 O 5 : 10 wt%, SO 3 : 0.3 wt%, Fe 2 O 3 : 0.2 wt%, with dolomite as the main component.

[0099] When the pH of the filtrate water is 10 and the specific gravity of the slurry is 1.45, the filtered phosphorus tailings cake is crushed by a crusher and then enters the finished product yard. Taking a storage quantity of 500 tons as a batch, after storing for 8 hours, through multi-point sampling, referring to the "Solid Waste Leaching Toxicity Leaching Method - Horizontal Oscillation Method" HJ557 - 2009, the Guizhou Detection Technology Research Center detects the leaching characteristics of the phosphorus tailings under water leaching conditions, and the results are shown in Table 4;

[0100] Table 4 Data table of the leaching characteristics of the phosphorus tailings after treatment in Example 1

[0101]

[0102]

[0103] Example 3

[0104] Based on the equipment in Example 1, carbide slag, the water treatment slag slurry produced by the water treatment station of Guizhou Chuanheng Chemical Co., Ltd., and the concentrated phosphorus tailings slurry discharged from the flotation workshop are fed in according to the dry basis ratio of carbide slag: water treatment slag: tailings = 0.7:20:79.3. First, the carbide slag and the water treatment slag slurry are stirred evenly in the conditioning modifier stirring tank according to the dry basis ratio of carbide slag: water treatment slag = 0.7:20, and then transported to the mixed slurry stirring tank in proportion through a flow meter and mixed evenly with the concentrated phosphorus tailings slurry. The mixed slurry is filtered by pressure filtration. During continuous production, by monitoring the pH value and specific gravity of the filtrate water of the mixed slurry, the dosages of carbide slag and water treatment slag are adjusted. The water treatment slag is secondary alkaline water treatment slag, with a specific gravity of 1.08 and a pH of 11. Its main chemical components include: P 2 O 5 : 15 wt%, fluoride: 0.2 wt%, CaO: 55 wt%, MgO: 10 wt%, SO 3 : 4 wt%, Al 2 O 3: 0.5 wt%, Fe 2 O 3 : 0.3 wt%; The carbide slag contains Ca(OH) 2 , the water content of the filter cake is 30%, and the main components are SiO 2 : 3 wt%, Al 2 O 3 : 0.9 wt%, CaO: 79 wt%, SO 3 : 0.1 wt%, Fe 2 O 3 : 0.05 wt%; The specific gravity of the phosphorus tailings thick slurry is 1.6, the concentration of the residual flocculant is 2.5 mg / L, the particle size of the phosphorus tailings is 150 - 180 um, and the main chemical components are CaO: 40 wt%, MgO: 20 wt%, SiO 2 : 4 wt%, fluoride 0.99 wt%, P 2 O 5 : 10 wt%, SO 3 : 0.3 wt%, Fe 2 O 3 : 0.2 wt%, with dolomite as the main component.

[0105] When the pH of the filtrate water is 10 and the specific gravity of the slurry is 1.45, the filtered phosphorus tailings filter cake is crushed by a crusher and then enters the finished product storage yard. Taking a storage volume of 500 tons as a batch, after storing for 3 days, 7 days, and 14 days, through multi-point sampling, the samples are air-dried and passed through a 2 mm test sieve to detect the proportion of agglomerated particles in the product. The results are shown in Table 5;

[0106] Table 5 Data table of the proportion of agglomerated particles in the products after different treatments of the phosphorus tailings thick slurry in this example

[0107]

[0108] Example 4

[0109] Based on the equipment in Example 1, carbide slag, the water treatment slag slurry produced by the water treatment station of Guizhou Chuanheng Chemical Co., Ltd., and the phosphorus tailings thick slurry discharged from the flotation workshop are fed in a dry basis ratio of carbide slag: water treatment slag: tailings = 0.7:20:79.3. First, the carbide slag and the water treatment slag slurry are stirred evenly in the conditioning modifier stirring tank according to the dry basis ratio of carbide slag: water treatment slag = 0.7:20, and then transported to the mixed slurry stirring tank in proportion through a flow meter and mixed evenly with the phosphorus tailings thick slurry. The mixed slurry is filtered by pressure filtration. During continuous production, the dosages of carbide slag and water treatment slag are adjusted by monitoring the pH value and specific gravity of the filtrate water of the mixed slurry. The water treatment slag is secondary alkaline water treatment slag, with a specific gravity of 1.08 and a pH of 11. Its main chemical components include: P 2 O5 : 15 wt%, fluoride: 0.2 wt%, CaO: 55 wt%, MgO: 10 wt%, SO 3 : 4 wt%, Al 2 O 3 : 0.5 wt%, Fe 2 O 3 : 0.3 wt%; the carbide slag contains Ca(OH) 2 , the water content of the filter cake is 30%, and the main components are SiO 2 : 3 wt%, Al 2 O 3 : 0.9 wt%, CaO: 79 wt%, SO 3 : 0.1 wt%, Fe 2 O 3 : 0.05 wt%; the specific gravity of the phosphorus tailings thick slurry is 1.6, the concentration of the residual flocculant is 2.5 mg / L, the particle size of the phosphorus tailings is 150 - 180 um, and the main chemical components are CaO: 40 wt%, MgO: 20 wt%, SiO 2 : 4 wt%, fluoride 0.99 wt%, P 2 O 5 : 10 wt%, SO 3 : 0.3 wt%, Fe 2 O 3 : 0.2 wt%, with dolomite as the main component. When the pH of the filtrate water is 10 and the specific gravity of the slurry is 1.45, the pressed phosphorus tailings filter cake is broken by a crusher and then enters the finished product yard. Taking 500 tons of storage as a batch, through multi-point sampling, the water content of the product is detected, and the results are shown in Table 6;

[0110] Table 6 Data table of the water content of the products after different treatments of the phosphorus tailings thick slurry in this example

[0111]

[0112] The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0113] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. Method for treating phosphorus tailings using a harmless treatment system, comprising the following steps: Mix a conditioning modifier and water to obtain a conditioning modifier slurry; Mix the conditioning modifier slurry and a thickened phosphorus tailings slurry to obtain a mixed slurry; the conditioning modifier is selected from water treatment slag; Perform pressure filtration on the mixed slurry to obtain a phosphorus tailings filter cake; Break up the phosphorus tailings filter cake and age it; The water treatment slag is alkaline water treatment slag, which includes: P 2 O 5 : 9 - 16 wt%, fluoride: 0.2 - 0.5 wt%, CaO: 50 - 60 wt%, MgO: 9 - 12 wt%, SO 3 : 2 - 4 wt%, Al 2 O 3 : 0.5 - 1 wt%, Fe 2 O 3 : 0.2 - 0.4 wt%; the alkaline water treatment slag includes primary precipitation water treatment slag and secondary precipitation water treatment slag. The pH of the primary precipitation water treatment slag is > 11, and the primary precipitation water treatment slag is directly used as a conditioning and modification agent. The pH of the secondary precipitation water treatment slag is 10 - 11, and the secondary precipitation water treatment slag needs to be used as a conditioning and modification agent together with carbide slag with a dry basis mass ratio of 0.2 - 1% in the thickened phosphate tailings slurry, and the pH > 11.

2. The method according to claim 1, characterized in that, the method further comprises: The filtrate after pressure filtration is used to adjust the pH of the mixed slurry after pH detection.

3. The method according to claim 1, characterized in that, The specific gravity of the thick phosphorus tailings slurry is 1.5 - 1.7, and the residual flocculant concentration is 0.6 - 3.0 mg / L; the particle size of the phosphorus tailings is 0 - 200 μm, and the main chemical components are CaO: 25 - 40 wt%, MgO: 10 - 20 wt%, SiO 2 : 1 - 4 wt%, fluoride: 0.99 wt%, P 2 O 5 : 4 - 10 wt%, SO 3 : 0.1 - 0.4 wt%, Fe 2 O 3 : 0.1 - 0.4 wt%, with dolomite as the main component.

4. The method according to claim 1 or 3, characterized in that, The water treatment slag is a liquid slurry with a specific gravity of 1.05 to 1.10 or a filter cake with a moisture content of 20 to 30% after pressure filtration. The carbide slag contains Ca(OH) 2 , and the moisture content is 20 to 30%.

5. The method according to claim 1, characterized in that, The specific gravity of the mixed slurry is 1.4 - 1.6, and the pH is 9.0 - 12.

0.

6. The method according to claim 1, characterized in that, The moisture content of the phosphorus tailings filter cake is 8 - 11%, the average particle size of the broken-up phosphorus tailings filter cake is 0.5 - 3 mm, and the aging time is 8 - 12 h.

7. The method according to claim 1, characterized in that, The harmless treatment system includes: a feed bin, a conditioning modifier stirring tank, a mixed material stirring tank, a plate and frame filter press, and a breaker; The outlet of the feed bin is connected to the inlet of the conditioning modifier stirring tank; The outlet of the conditioning modifier stirring tank is connected to the first inlet of the mixed material stirring tank; The outlet of the mixed material stirring tank is connected to the inlet of the plate and frame filter press; The first outlet of the plate and frame filter press is connected to the inlet of the breaker; The inlet of the conditioning modifier stirring tank is also connected to the outlet of a high-level water tank; The second inlet of the mixed material stirring tank is also connected to the outlet of a thickened phosphorus tailings slurry tank; The second outlet of the plate and frame filter press is connected to the third inlet of the mixed material stirring tank.

8. The method according to claim 7, characterized in that, A flow meter is provided between the high-level water tank and the conditioning modifier stirring tank; a slurry pump and a flow meter are provided between the conditioning modifier stirring tank and the mixed material stirring tank.

9. The method according to claim 7 or 8, characterized in that, A flow meter is provided between the thickened phosphorus tailings slurry tank and the mixed material stirring tank, a slurry pump is provided between the mixed material stirring tank and the plate and frame filter press, and a pH meter is provided between the plate and frame filter press and the mixed material stirring tank.

10. The method according to claim 7, characterized in that, The conditioning modifier stirring tank is a single-shaft horizontal paddle stirring tank, the mixed material stirring tank is a double-shaft horizontal paddle stirring tank, the plate and frame filter press is a water-washed plate and frame filter press, and the breaker is a rotary sieve bar type flying knife breaker.

11. The method according to any one of claims 7 - 10, characterized in that, It further includes a finished product storage yard, and the finished product storage yard is arranged below the breaker.

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