Method for recycling apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology

Abstract

The invention discloses a method for recycling apatite and amorphous SiO2 by using an ultrasonic enhanced cyclone separation technology, and belongs to the field of separation and extraction of apatite and amorphous SiO2. According to the method, gypsum phase and non-gypsum phase components in ardealite are deeply separated by virtue of a gypsum crystal reconstruction theory, and then the obtained ardealite tailings are subjected to ammonia leaching and solid-liquid separation to obtain an ammonium humate solution and tailings rich in SiO2 and apatite. The phosphogypsum tailings are used as a raw material, and silicon dioxide monomers and apatite are depolymerized by virtue of ultrasonic waves and a dispersing agent, so that the two phases are completely dissociated. In the state, SiO2 is gradually deposited at the bottom through cyclone separation, apatite flows out from the top, apatite concentrate and a SiO2-rich phase are obtained, the grade of SiO2 is larger than or equal to 95%, and the grade of apatite is larger than or equal to 90%. The technology not only can realize effective separation of silicon dioxide and apatite in the ardealite, but also is helpful for realizing comprehensive resource utilization of the ardealite.

Description

Technical Field

[0001] The invention belongs to the field of separation and extraction of apatite and amorphous SiO2, and specifically relates to a method for recovering apatite and amorphous SiO2 by utilizing ultrasonic enhanced cyclone separation technology. Background Art

[0002] my country is a major chemical industry country, and the demand for new energy phosphorus batteries has surged in recent years, which has greatly promoted the development of the phosphorus chemical industry, resulting in a further increase in the emission of phosphogypsum, which now exceeds 80 million tons per year. Apatite is the main raw material for the production of phosphate fertilizers and phosphorus products. Sulfuric acid leaching is often used to obtain phosphoric acid, which can be used to prepare phosphate fertilizers suitable for agricultural use, new energy storage materials and phosphorus solid-state batteries.

[0003] In addition to a large amount of gypsum phase, phosphogypsum also contains silicon dioxide, apatite and organic matter in the tailings, of which the mass percentage of silicon dioxide can reach more than 8%, and the content of unreacted apatite is about more than 5%, and even as high as about 10%. Therefore, effectively recovering the gypsum, apatite and silicon dioxide phases in phosphogypsum can not only improve the comprehensive utilization rate of phosphogypsum, save resources and protect the environment, but also have significant economic and environmental benefits.

[0004] From the perspective of energy conservation, emission reduction and environmental protection, the recycling of solid waste resources has received much attention from the country, and great support has been given in terms of policies and taxes. There are many literatures on the resource utilization of phosphogypsum, which mainly focus on the use of phosphogypsum through a simple calcination process to prepare semi-hydrated gypsum for use in the building materials industry. However, due to its low added value and limited market absorption, it has seriously restricted the green development of the phosphorus chemical industry. How to turn phosphogypsum resources into treasure has been the goal of continuous research and development in the phosphorus chemical industry for many years. This patent proposes for the first time a treatment method that uses synergistic metallurgy for the comprehensive utilization of phosphogypsum resources, combining hydrometallurgical methods with mineral processing technology, aiming to achieve the comprehensive utilization of phosphogypsum while minimizing production costs, reducing environmental pollution, and improving the market cost performance of products.

[0005] Since phosphogypsum contains about 85% gypsum phase and about 4% humic acid, after the gypsum and humic acid in phosphogypsum are recycled, the reasonable disposal of the residual apatite and silica phase becomes a limiting link in the comprehensive utilization of phosphogypsum resources. If this part of the tailings is directly stored or landfilled as solid waste, it will not only cause a waste of resources, but also easily pollute the environment; if apatite and silica can be separated from it, it will not only solve the problem of efficient utilization of phosphogypsum, but also achieve the "dry squeeze" of phosphogypsum, and maximize the solution to the problem of no waste discharge of phosphogypsum in the process of realizing comprehensive resource utilization, which can greatly promote the sustainable development of the phosphorus chemical industry. However, at present, there are no reports on patents and literature on the extraction of silica and apatite from phosphogypsum.

[0006] In summary, improving the high-value and large-scale utilization technology of phosphogypsum has always been the goal pursued by the phosphorus chemical industry. To achieve this goal, the first task must be to improve the quality and whiten the phosphogypsum, but the effective disposal of the tailings after the improvement and whitening seriously restricts the clean production of this technology. Summary of the invention

[0007] In view of the common problems in the existing comprehensive utilization of phosphogypsum resources, the present invention provides a new combined beneficiation and smelting intensified process technology, which can recover high-purity and high-whiteness gypsum from phosphogypsum, and extract apatite and silicon dioxide from the tailings after humic acid, that is, it is used to solve the problem of "waste-free" emissions in the process of clean, high-value, resource-based and large-scale comprehensive utilization of phosphogypsum. The technology of the present invention has the advantages of short process, easy control, small investment, low cost, no environmental problems, etc., and is of great significance to the sustainable development of phosphorus chemical industry.

[0008] The main purpose of the present invention is achieved through the following solutions:

[0009] In the tailings after the gypsum and humic acid phases in the phosphogypsum are completely separated, combined with the embedded characteristics of silica and apatite, the silicon-rich phase and apatite in the tailings are depolymerized by ultrasonic enhancement and using a dispersant, so that the silica and apatite phases are fully dispersed, and then the large particles of silica are separated from the small particles of apatite by means of a cyclone beneficiation method, and finally high-purity silica and apatite products can be obtained. The solution after the products are separated can be returned to the system for recycling.

[0010] A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, specifically comprising the following steps:

[0011] S1. Preparation of slurry: mixing phosphogypsum tailings with water at room temperature, then adding a super-dispersed surfactant and stirring to obtain a slurry;

[0012] S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe, and the cavitation effect generated by ultrasonic oscillation is used for oscillation separation, so that the silicon dioxide monomer and apatite in the tailings are depolymerized to obtain a phosphorus-rich and silicon-rich suspension;

[0013] S3. Cyclone separation: The suspension obtained in step S2 enters the feed port of the ultrasonic cyclone separator at a certain tangential velocity, and the apatite is blown to the upper layer and flows out from the upper flow port by controlling the radial flow rate, and the silicon dioxide is deposited at the bottom by gravity sedimentation and flows out from the lower flow port to obtain an apatite concentrate and a SiO2-rich phase;

[0014] S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling;

[0015] S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

[0016] in:

[0017] In the step S1, the phosphogypsum tailings are specifically tailings obtained from the recovery of gypsum and humic acid from the phosphogypsum.

[0018] In the step S1, the solid-liquid ratio of phosphogypsum tailings to water is 1: (10-20) g / mL.

[0019] In the step S1, the ultra-dispersed surfactant is specifically sodium dodecyl sulfate or sodium dodecylbenzene sulfonate, and the added amount is 0.05% to 0.2% of the phosphogypsum tailings by mass fraction.

[0020] In the step S2, the ultrasonic oscillation power is controlled at 20W to 100W, and the slurry is exposed to the ultrasonic strengthening probe for 5s to 20s.

[0021] In the step S3, in the ultrasonic cyclone separator, the tangential flow velocity of the suspension is 0.1 m / s to 0.6 m / s, and the radial flow velocity is 0.01 m / s to 0.1 m / s.

[0022] In the step S4, the purity of the high-grade apatite is ≥ 90%.

[0023] In step S5, the purity of the high-grade silicon dioxide product is ≥95%.

[0024] The main principles of the ultrasonic enhanced separation method adopted in the present invention are:

[0025] The agglomeration of silica and apatite in the tailings after gypsum and humic acid are extracted from phosphogypsum is serious, making it difficult to separate and extract them by conventional sorting methods. The present invention uses the ultrasonic cavitation effect, the large difference in particle size between silica and apatite, and the use of ultra-dispersed surfactants to reduce the electrostatic force between particles, which is used to solve the problem that small particles of apatite and large particles of silica are difficult to effectively separate due to agglomeration. Under this environment, the cyclone technology is used to finally achieve the rapid separation of small particles and large particles, thereby producing silica and apatite products with high utilization value.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The ultrasonic enhanced cyclone separation combined technology for extracting silicon dioxide and apatite from phosphogypsum of the present invention can overcome the insufficient extraction of phosphogypsum by the prior art and obtain silicon dioxide and apatite components with higher purity.

[0028] (2) The present invention utilizes the combined technology of ultrasonic enhancement and cyclone separation to improve the separation efficiency by controlling the process parameters, thereby achieving the "full utilization" of phosphogypsum, and solving the problem of zero waste discharge of phosphogypsum in the process of realizing comprehensive resource utilization to the greatest extent.

[0029] (3) The present invention uses a coordinated treatment method of mineral processing and smelting to comprehensively utilize phosphogypsum resources, combining hydrometallurgical methods with mineral processing technology, which not only realizes the comprehensive utilization of phosphogypsum, but also reduces production costs as much as possible, reduces environmental pollution, improves the market cost performance of products, and greatly improves the purity of silicon dioxide and apatite in tailings.

[0030] (4) The present invention provides a clean production technology with high practicability, simple process, low energy consumption, strong adaptability and no waste liquid generation problem. It is a clean method for extracting silicon dioxide and apatite with broad application prospects, and can solve the problem of "waste-free" emission in the process of clean, high-value, resource-based and large-scale comprehensive utilization of phosphogypsum. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A process flow chart of the present invention for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology. DETAILED DESCRIPTION

[0032] In order to make the technical solutions, creative purposes and advantages achieved by the present invention more clearly understood, the present invention is further described below in conjunction with specific embodiments.

[0033] Example 1

[0034] A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, the process flow chart is as follows Figure 1 As shown, the specific steps include:

[0035] S1. Prepare slurry: take tailings obtained after recovering gypsum and humic acid from phosphogypsum as raw material, mix with water at room temperature, the solid-liquid ratio of phosphogypsum tailings to water is 1:20 g / mL, then add sodium dodecylbenzene sulfonate, the addition amount is 0.15% of the phosphogypsum tailings by mass fraction, stir evenly to obtain slurry;

[0036] S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe with an ultrasonic oscillation power of 20W and an action time of 20s. The cavitation effect generated by ultrasonic oscillation is used for oscillation separation to depolymerize the coarse particles of silicon dioxide monomers and the ultrafine particles of apatite in the tailings to obtain a phosphorus-rich and silicon-rich suspension;

[0037] S3. Cyclone separation: The suspension obtained in step S2 enters the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.4 m / s, and the fine particles of apatite are blown to the upper layer and flow out from the top upper flow port by controlling the radial flow velocity to 0.01 m / s. The silica particles with a larger specific gravity are deposited at the bottom by gravity sedimentation and flow out from the lower flow port to obtain apatite concentrate and SiO2-rich phase;

[0038] S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling;

[0039] S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

[0040] The purity of the high-grade apatite obtained in this example is 90.6%, and the purity of the high-grade silicon dioxide product is 96.4%.

[0041] Example 2

[0042] A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, specifically comprising the following steps:

[0043] S1. Prepare slurry: take tailings obtained after recovering gypsum and humic acid from phosphogypsum as raw material, mix with water at room temperature, the solid-liquid ratio of phosphogypsum tailings to water is 1:16 g / mL, then add sodium dodecylbenzene sulfonate, the addition amount is 0.05% of the phosphogypsum tailings by mass fraction, stir evenly to obtain slurry;

[0044] S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe with an ultrasonic oscillation power of 45W and an action time of 15s. The cavitation effect generated by ultrasonic oscillation is used for oscillation separation to depolymerize the coarse particles of silicon dioxide monomers and the ultrafine particles of apatite in the tailings to obtain a phosphorus-rich and silicon-rich suspension;

[0045] S3. Cyclone separation: The suspension obtained in step S2 enters the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.6 m / s, and the fine particles of apatite are blown to the upper layer and flow out from the top upper flow port by controlling the radial flow velocity to 0.1 m / s. The silica particles with a larger specific gravity are deposited at the bottom by gravity sedimentation and flow out from the lower flow port to obtain apatite concentrate and SiO2-rich phase;

[0046] S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling;

[0047] S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

[0048] The purity of the high-grade apatite obtained in this example is 91.5%, and the purity of the high-grade silicon dioxide product is 95.8%.

[0049] Example 3

[0050] A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, specifically comprising the following steps:

[0051] S1. Prepare slurry: take tailings obtained after recovering gypsum and humic acid from phosphogypsum as raw material, mix with water at room temperature, the solid-liquid ratio of phosphogypsum tailings to water is 1:12 g / mL, then add sodium dodecylbenzene sulfonate, the addition amount is 0.2% of the phosphogypsum tailings by mass fraction, stir evenly to obtain slurry;

[0052] S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe with an ultrasonic oscillation power of 70W and an action time of 10s. The cavitation effect generated by ultrasonic oscillation is used for oscillation separation to depolymerize the coarse particles of silicon dioxide monomers and the ultrafine particles of apatite in the tailings to obtain a phosphorus-rich and silicon-rich suspension;

[0053] S3. Cyclone separation: The suspension obtained in step S2 is fed into the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.1 m / s, and the radial flow rate is controlled to be 0.01 m / s, so that the fine particles of apatite are blown to the upper layer and flow out from the upper flow port at the top, and the silica particles with a larger specific gravity are deposited at the bottom by gravity sedimentation and flow out from the lower flow port to obtain apatite concentrate and SiO2-rich phase;

[0054] S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling;

[0055] S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

[0056] The purity of the high-grade apatite obtained in this example is 91.8%, and the purity of the high-grade silicon dioxide product is 97.3%.

[0057] Example 4

[0058] A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, specifically comprising the following steps:

[0059] S1. Prepare slurry: take tailings obtained after recovering gypsum and humic acid from phosphogypsum as raw material, mix with water at room temperature, the solid-liquid ratio of phosphogypsum tailings to water is 1:10 g / mL, then add sodium dodecylbenzene sulfonate, the addition amount is 0.1% of the phosphogypsum tailings by mass fraction, stir evenly to obtain slurry;

[0060] S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe with an ultrasonic oscillation power of 100 W and an action time of 5 seconds. The cavitation effect generated by ultrasonic oscillation is used for oscillation separation to depolymerize the coarse particles of silicon dioxide monomers and the ultrafine particles of apatite in the tailings to obtain a phosphorus-rich and silicon-rich suspension;

[0061] S3. Cyclone separation: The suspension obtained in step S2 is fed into the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.2 m / s, and the radial flow rate is controlled to be 0.04 m / s, so that the fine particles of apatite are blown to the upper layer and flow out from the upper flow port at the top, and the silica particles with a larger specific gravity are deposited at the bottom by gravity sedimentation and flow out from the lower flow port to obtain apatite concentrate and SiO2-rich phase;

[0062] S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling;

[0063] S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

[0064] The purity of the high-grade apatite obtained in this example is 92.3%, and the purity of the high-grade silicon dioxide product is 96.9%.

[0065] Example 5

[0066] A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, specifically comprising the following steps:

[0067] S1. Prepare slurry: take tailings obtained after recovering gypsum and humic acid from phosphogypsum as raw material, mix with water at room temperature, the solid-liquid ratio of phosphogypsum tailings to water is 1:18 g / mL, then add sodium dodecyl sulfate, the addition amount is 0.15% of the phosphogypsum tailings by mass fraction, stir evenly to obtain slurry;

[0068] S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe with an ultrasonic oscillation power of 70W and an action time of 10s. The cavitation effect generated by ultrasonic oscillation is used for oscillation separation to depolymerize the coarse particles of silicon dioxide monomers and the ultrafine particles of apatite in the tailings to obtain a phosphorus-rich and silicon-rich suspension;

[0069] S3. Cyclone separation: The suspension obtained in step S2 enters the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.3 m / s, and the fine particles of apatite are blown to the upper layer and flow out from the top upper flow port by controlling the radial flow velocity to 0.02 m / s. The silica particles with a larger specific gravity are deposited at the bottom by gravity sedimentation and flow out from the lower flow port to obtain apatite concentrate and SiO2-rich phase;

[0070] S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling;

[0071] S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

[0072] The purity of the high-grade apatite obtained in this example is 90.9%, and the purity of the high-grade silicon dioxide product is 97.6%.

[0073] Example 6

[0074] A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, specifically comprising the following steps:

[0075] S1. Prepare slurry: take tailings obtained after recovering gypsum and humic acid from phosphogypsum as raw material, mix with water at room temperature, the solid-liquid ratio of phosphogypsum tailings to water is 1:15 g / mL, then add sodium dodecyl sulfate, the addition amount is 0.1% of the phosphogypsum tailings by mass fraction, stir evenly to obtain slurry;

[0076] S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe with an ultrasonic oscillation power of 60W and an action time of 15s. The cavitation effect generated by ultrasonic oscillation is used for oscillation separation to depolymerize the coarse particles of silicon dioxide monomers and the ultrafine particles of apatite in the tailings to obtain a phosphorus-rich and silicon-rich suspension;

[0077] S3. Cyclone separation: The suspension obtained in step S2 enters the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.5 m / s, and the fine particles of apatite are blown to the upper layer and flow out from the top upper flow port by controlling the radial flow velocity to 0.08 m / s. The silica particles with a larger specific gravity are deposited at the bottom by gravity sedimentation and flow out from the lower flow port to obtain apatite concentrate and SiO2-rich phase;

[0078] S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling;

[0079] S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

[0080] The purity of the high-grade apatite obtained in this example is 91.6%, and the purity of the high-grade silicon dioxide product is 95.5%.

[0081] Example 7

[0082] A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, specifically comprising the following steps:

[0083] S1. Prepare slurry: take tailings obtained after recovering gypsum and humic acid from phosphogypsum as raw material, mix with water at room temperature, the solid-liquid ratio of phosphogypsum tailings to water is 1:10 g / mL, then add sodium dodecyl sulfate, the addition amount is 0.2% of the phosphogypsum tailings by mass fraction, stir evenly to obtain slurry;

[0084] S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe with an ultrasonic oscillation power of 90W and an action time of 5s. The cavitation effect generated by ultrasonic oscillation is used for oscillation separation to depolymerize the coarse particles of silicon dioxide monomers and the ultrafine particles of apatite in the tailings to obtain a phosphorus-rich and silicon-rich suspension;

[0085] S3. Cyclone separation: The suspension obtained in step S2 is fed into the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.1 m / s, and the radial flow rate is controlled to be 0.01 m / s, so that the fine particles of apatite are blown to the upper layer and flow out from the upper flow port at the top, and the silica particles with a larger specific gravity are deposited at the bottom by gravity sedimentation and flow out from the lower flow port to obtain apatite concentrate and SiO2-rich phase;

[0086] S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling;

[0087] S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

[0088] The purity of the high-grade apatite obtained in this example is 92.8%, and the purity of the high-grade silicon dioxide product is 96.2%.

[0089] Example 8

[0090] A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, specifically comprising the following steps:

[0091] S1. Prepare slurry: take tailings obtained after recovering gypsum and humic acid from phosphogypsum as raw material, mix with water at room temperature, the solid-liquid ratio of phosphogypsum tailings to water is 1:12 g / mL, then add sodium dodecyl sulfate, the addition amount is 0.05% of the phosphogypsum tailings by mass fraction, stir evenly to obtain slurry;

[0092] S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe with an ultrasonic oscillation power of 80W and an action time of 5s. The cavitation effect generated by ultrasonic oscillation is used for oscillation separation to depolymerize the coarse particles of silicon dioxide monomers and the ultrafine particles of apatite in the tailings to obtain a phosphorus-rich and silicon-rich suspension;

[0093] S3. Cyclone separation: The suspension obtained in step S2 is fed into the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.2 m / s, and the radial flow rate is controlled to be 0.03 m / s, so that the fine particles of apatite are blown to the upper layer and flow out from the upper flow port at the top, and the silica particles with a larger specific gravity are deposited at the bottom by gravity sedimentation and flow out from the lower flow port to obtain apatite concentrate and SiO2-rich phase;

[0094] S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling;

[0095] S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

[0096] The purity of the high-grade apatite obtained in this example is 92.1%, and the purity of the high-grade silicon dioxide product is 97.7%.

Claims

1. A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology, characterized in that: The specific steps include: S1. Preparation of slurry: mixing phosphogypsum tailings with water at room temperature, then adding a super-dispersed surfactant and stirring to obtain a slurry; S2. Ultrasonic enhanced separation: The slurry is placed under an ultrasonic enhanced probe, and the cavitation effect generated by ultrasonic oscillation is used for oscillation separation, so that the silicon dioxide monomer and apatite in the tailings are depolymerized to obtain a phosphorus-rich and silicon-rich suspension; S3. Cyclone separation: The suspension obtained in step S2 enters the feed port of the ultrasonic cyclone separator at a certain tangential velocity, and the apatite is blown to the upper layer and flows out from the upper flow port by controlling the radial flow rate, and the silicon dioxide is deposited at the bottom by gravity sedimentation and flows out from the lower flow port to obtain an apatite concentrate and a SiO2-rich phase; S4. Vacuum belt separation at the upstream port: The slurry at the upstream port is separated by vacuum belt filtration to obtain high-grade apatite, and the separated solution is returned to step S1 as a slurry for recycling; S5. Vacuum belt separation at the downstream port: The slurry at the downstream port is separated by vacuum belt filtration to obtain high-grade silicon dioxide, and the separated solution is returned to step S1 for recycling as slurry.

2. The method for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology according to claim 1, characterized in that: In the step S1, the phosphogypsum tailings are specifically tailings obtained from the recovery of gypsum and humic acid from the phosphogypsum.

3. The method for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology according to claim 1, characterized in that: In the step S1, the solid-liquid ratio of phosphogypsum tailings to water is 1: (10-20) g / mL.

4. The method for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology according to claim 1, characterized in that: In the step S1, the ultra-dispersed surfactant is specifically sodium dodecyl sulfate or sodium dodecylbenzene sulfonate, and the added amount is 0.05% to 0.2% of the phosphogypsum tailings by mass fraction.

5. The method for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology according to claim 1, characterized in that: In the step S2, the ultrasonic oscillation power is controlled at 20W to 100W, and the slurry is exposed to the ultrasonic strengthening probe for 5s to 20s.

6. The method for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology according to claim 1, characterized in that: In the step S3, in the ultrasonic cyclone separator, the tangential flow velocity of the suspension is 0.1 m / s to 0.6 m / s, and the radial flow velocity is 0.01 m / s to 0.1 m / s.

7. The method for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology according to claim 1, characterized in that: In the step S4, the purity of the high-grade apatite is ≥ 90%.

8. The method for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology according to claim 1, characterized in that: In step S5, the purity of the high-grade silicon dioxide product is ≥95%.

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