A method for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology

Abstract

The application discloses a method for recovering apatite and amorphous SiO2 by using ultrasonic enhanced cyclone separation technology, and belongs to the field of apatite and amorphous SiO2 separation and extraction. According to the gypsum crystal reconstruction theory, the gypsum phase and non-gypsum phase components in phosphogypsum are deeply separated, the obtained phosphogypsum tailings are subjected to ammonia immersion and solid-liquid separation, and an ammonium humate solution and tailings rich in SiO2 and apatite are obtained. The application takes the phosphogypsum tailings as raw materials, and uses ultrasonic waves and dispersants to depolymerize the silicon dioxide monomers and apatite, so that the two phases are completely dissociated. In this state, the SiO2 is gradually deposited at the bottom through cyclone separation, and the apatite flows out from the top, and then apatite concentrate and SiO2-rich phase are obtained, wherein the grade of SiO2 is greater than or equal to 95%, and the grade of apatite is greater than or equal to 90%. The technology can not only realize the effective separation of silicon dioxide and apatite in phosphogypsum, but also help realize the comprehensive utilization of phosphogypsum resources.

Description

Technical Field

[0001] This invention belongs to the field of separation and extraction of apatite and amorphous SiO2, specifically relating to a method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology. Background Technology

[0002] As a major chemical industry country, my country has seen a surge in demand for new energy phosphorus batteries in recent years, which has greatly promoted the development of the phosphorus chemical industry and led to a further continuous increase in the emissions of phosphogypsum. Apatite, as the main raw material for the production of phosphate fertilizers and phosphorus products, is often used in sulfuric acid leaching to obtain phosphoric acid, which can then 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, phosphogypsum tailings also contain silica, apatite, and organic matter. Silica can account for over 8% of the total mass, and unreacted apatite contains approximately 5% or more, with some cases reaching as high as 10%. Therefore, effectively recovering gypsum, apatite, and silica from phosphogypsum can not only improve its comprehensive utilization rate and conserve resources while protecting the environment, but also yield 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 significant national attention, with substantial policy and tax support. While there is considerable literature on the resource utilization of phosphogypsum, it primarily focuses on preparing hemihydrate gypsum through a simple calcination process for use in the building materials industry. However, due to its low added value and limited market absorption, this severely restricts the green development of the phosphate chemical industry. How to transform phosphogypsum resources from waste into valuable resources has been a long-term research and development goal for the phosphate chemical industry. This patent is the first to propose a combined metallurgical and beneficiation treatment method for the comprehensive utilization of phosphogypsum resources. By combining hydrometallurgical methods with mineral processing technology, it aims to achieve comprehensive utilization of phosphogypsum while minimizing production costs, reducing environmental pollution, and improving the market cost-effectiveness of the products.

[0005] Since phosphogypsum contains approximately 85% gypsum phase and 4% humic acid, the proper disposal of the remaining apatite and silica phases after the gypsum and humic acid are recovered becomes a limiting factor in the comprehensive utilization of phosphogypsum resources. Directly stockpiling or landfilling this tailings as solid waste not only wastes resources but also pollutes the environment. Separating apatite and silica from it would not only solve the problem of efficient phosphogypsum utilization but also achieve complete extraction, maximizing the zero-waste discharge in the process of comprehensive resource utilization and greatly promoting the sustainable development of the phosphate chemical industry. However, currently, no patents or literature have been reported regarding 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 a goal pursued by the phosphate chemical industry. To achieve this goal, the primary task must be to upgrade and whiten phosphogypsum. However, the effective disposal of the tailings after upgrading and whitening severely restricts the clean production of this technology. Summary of the Invention

[0007] To address common problems in the existing comprehensive utilization of phosphogypsum resources, this invention provides a novel combined beneficiation and smelting enhanced process technology. This technology can recover high-purity, high-whiteness gypsum, extract apatite and silica from the tailings of humic acid from phosphogypsum, thus solving the problem of "zero-waste" emissions in the clean, high-value, resource-based, and large-scale comprehensive utilization of phosphogypsum. This invention has advantages such as a short process, ease of operation, low investment, low cost, and no environmental problems, and is of great significance to the sustainable development of the phosphate chemical industry.

[0008] The main objective of this invention is achieved through the following approach:

[0009] In the tailings after the gypsum and humic acid phases in phosphogypsum have been completely separated, taking into account the embedded characteristics of silica and apatite, the silica-rich phase and apatite in the tailings are deagglomerated by ultrasonic enhancement and the use of a dispersant, so that the silica and apatite phases are fully dispersed. Then, the large silica particles and small apatite particles are separated by hydrocyclone mineral processing, and finally, high-purity silica and apatite products can be obtained. The solution after the separation of products can be returned to the system for recycling.

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

[0011] S1. Preparation of slurry: Mix phosphogypsum tailings with water at room temperature, then add super-dispersible surfactant and stir until uniform to obtain slurry;

[0012] S2. Ultrasonic Enhanced Separation: The slurry is placed under an ultrasonic enhancement probe, and the cavitation effect generated by ultrasonic oscillation is used to separate the slurry, causing the silica monomers and apatite in the tailings to depolymerize, resulting in a phosphorus- and silicon-rich suspension.

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

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

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

[0016] in:

[0017] In step S1, the phosphogypsum tailings are specifically the tailings obtained after phosphogypsum has been recycled into gypsum and humic acid.

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

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

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

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

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

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

[0024] The main principle of the ultrasonic enhanced separation method used in this invention is as follows:

[0025] In the tailings from the extraction of gypsum and humic acid from phosphogypsum, silica and apatite exhibit severe agglomeration, making separation and extraction difficult using conventional sorting methods. This invention utilizes the ultrasonic cavitation effect and the significant particle size difference between silica and apatite. A super-dispersing surfactant reduces the electrostatic forces between particles, addressing the difficulty in effectively separating small apatite particles from large silica particles due to agglomeration. Under these conditions, a cyclone technique is then employed to achieve rapid separation of small and large particles, ultimately producing silica and apatite products with high utilization value.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) The ultrasonic enhanced cyclone separation technology for extracting silica and apatite from phosphogypsum in this invention can overcome the insufficient extraction of phosphogypsum by existing technology and obtain silica and apatite components with high purity.

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

[0029] (3) This invention utilizes a combined metallurgical and mineral processing method for the comprehensive utilization of phosphogypsum resources. By combining hydrometallurgical methods with mineral processing technology, it not only achieves comprehensive utilization of phosphogypsum, but also minimizes production costs, reduces environmental pollution, improves the market cost-effectiveness of products, and significantly increases the purity of silica and apatite in tailings.

[0030] (4) This invention provides a clean production technology that is highly practical, simple in process, low in energy consumption, highly adaptable and has no waste liquid generation problem. It is a clean extraction method for silica and apatite with broad application prospects. It can solve the problem of "zero waste" discharge in the process of clean, high-value, resource-based and large-scale comprehensive utilization of phosphogypsum. Attached Figure Description

[0031] Figure 1 A process flow diagram of the present invention for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclone separation technology. Detailed Implementation

[0032] To make the technical solution, creative purpose and advantages of the present invention clearer, the present invention will be further described below with reference to specific embodiments.

[0033] Example 1

[0034] A method for recovering apatite and amorphous SiO2 using ultrasonic-enhanced cyclone separation technology is illustrated in the following process flow diagram: Figure 1 As shown, the specific steps include:

[0035] S1. Preparation of slurry: The tailings obtained after phosphogypsum is recycled from gypsum and humic acid are used as raw materials. The slurry is mixed with water at room temperature. The solid-liquid ratio of phosphogypsum tailings to water is 1:20 g / mL. Then sodium dodecylbenzenesulfonate is added. The amount added is 0.15% of the phosphogypsum tailings by mass fraction. The mixture is stirred evenly to obtain the slurry.

[0036] S2. Ultrasonic Enhanced Separation: The slurry is placed under an ultrasonic enhancement probe with an ultrasonic oscillation power of 20 W and an action time of 20 s. The cavitation effect generated by the ultrasonic oscillation is used to separate the coarse silica monomers and the ultrafine apatite particles in the tailings, resulting in a phosphorus- and silicon-rich suspension.

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

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

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

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

[0041] Example 2

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

[0043] S1. Preparation of slurry: Using the tailings obtained from the recovery of phosphogypsum and humic acid 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 dodecylbenzenesulfonate, which is added at 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 enhancement probe with an ultrasonic oscillation power of 45 W and an action time of 15 s. The cavitation effect generated by the ultrasonic oscillation is used to separate the coarse silica monomers and the ultrafine apatite particles in the tailings, resulting in a phosphorus- and silicon-rich suspension.

[0045] S3. Cyclone Separation: The suspension obtained in step S2 is introduced into the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.6 m / s. By controlling the radial flow velocity to 0.1 m / s, the fine apatite particles are blown to the upper layer and flow out from the top outlet. The silica particles with a higher specific gravity are deposited at the bottom by gravity sedimentation and flow out from the bottom outlet, thus obtaining apatite concentrate and SiO2-rich phase.

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

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

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

[0049] Example 3

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

[0051] S1. Preparation of slurry: Using the 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 dodecylbenzenesulfonate, which is added at 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 enhancement probe with an ultrasonic oscillation power of 70 W and an action time of 10 s. The cavitation effect generated by the ultrasonic oscillation is used to separate the coarse silica monomers and the ultrafine apatite particles in the tailings, resulting in a phosphorus- and silicon-rich suspension.

[0053] S3. Cyclone Separation: The suspension obtained in step S2 is introduced into the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.1 m / s. By controlling the radial flow velocity to 0.01 m / s, the fine apatite particles are blown to the upper layer and flow out from the top outlet. The silica particles with a higher specific gravity are deposited at the bottom by gravity sedimentation and flow out from the bottom outlet, thus obtaining apatite concentrate and SiO2-rich phase.

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

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

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

[0057] Example 4

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

[0059] S1. Preparation of slurry: Using the 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 dodecylbenzenesulfonate, which is added at 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 enhancement probe with an ultrasonic oscillation power of 100 W and an action time of 5 s. The cavitation effect generated by the ultrasonic oscillation is used to separate the coarse silica monomers and the ultrafine apatite particles in the tailings, resulting in a phosphorus- and silicon-rich suspension.

[0061] S3. Cyclone Separation: The suspension obtained in step S2 is introduced into the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.2 m / s. By controlling the radial flow velocity to 0.04 m / s, the fine apatite particles are blown to the upper layer and flow out from the top outlet. The silica particles with a higher specific gravity are deposited at the bottom by gravity sedimentation and flow out from the bottom outlet, thus obtaining apatite concentrate and SiO2-rich phase.

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

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

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

[0065] Example 5

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

[0067] S1. Preparation of slurry: Using the tailings obtained from the recovery of phosphogypsum and humic acid 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, which 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 enhancement probe with an ultrasonic oscillation power of 70 W and an action time of 10 s. The cavitation effect generated by the ultrasonic oscillation is used to separate the coarse silica monomers and the ultrafine apatite particles in the tailings, resulting in a phosphorus- and silicon-rich suspension.

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

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

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

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

[0073] Example 6

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

[0075] S1. Preparation of slurry: Using the 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, which is added at 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 enhancement probe with an ultrasonic oscillation power of 60 W and an action time of 15 s. The cavitation effect generated by the ultrasonic oscillation is used to separate the coarse silica monomers and the ultrafine apatite particles in the tailings, resulting in a phosphorus- and silicon-rich suspension.

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

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

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

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

[0081] Example 7

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

[0083] S1. Preparation of slurry: Using the tailings obtained from the recovery of phosphogypsum and humic acid 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, which is added at a mass fraction of 0.2% of the phosphogypsum tailings. Stir evenly to obtain slurry.

[0084] S2. Ultrasonic Enhanced Separation: The slurry is placed under an ultrasonic enhancement probe with an ultrasonic oscillation power of 90 W and an action time of 5 s. The cavitation effect generated by the ultrasonic oscillation is used to separate the coarse silica monomers and the ultrafine apatite particles in the tailings, resulting in a phosphorus- and silicon-rich suspension.

[0085] S3. Cyclone Separation: The suspension obtained in step S2 is introduced into the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.1 m / s. By controlling the radial flow velocity to 0.01 m / s, the fine apatite particles are blown to the upper layer and flow out from the top outlet. The silica particles with a higher specific gravity are deposited at the bottom by gravity sedimentation and flow out from the bottom outlet, thus obtaining apatite concentrate and SiO2-rich phase.

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

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

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

[0089] Example 8

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

[0091] S1. Preparation of slurry: The tailings obtained after phosphogypsum is recycled from gypsum and humic acid are used as raw materials. The slurry is mixed with water at room temperature. The solid-liquid ratio of phosphogypsum tailings to water is 1:12 g / mL. Then sodium dodecyl sulfate is added. The amount added is 0.05% of the phosphogypsum tailings by mass fraction. The mixture is stirred evenly to obtain the slurry.

[0092] S2. Ultrasonic Enhanced Separation: The slurry is placed under an ultrasonic enhancement probe with an ultrasonic oscillation power of 80 W and an action time of 5 s. The cavitation effect generated by the ultrasonic oscillation is used to separate the coarse silica monomers and the ultrafine apatite particles in the tailings, resulting in a phosphorus- and silicon-rich suspension.

[0093] S3. Cyclone Separation: The suspension obtained in step S2 is introduced into the feed port of the ultrasonic cyclone separator at a tangential velocity of 0.2 m / s. By controlling the radial flow velocity to 0.03 m / s, the fine apatite particles are blown to the upper layer and flow out from the top outlet. The silica particles with a higher specific gravity are deposited at the bottom by gravity sedimentation and flow out from the bottom outlet, thus obtaining apatite concentrate and SiO2-rich phase.

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

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

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

Claims

1. A method for recovering apatite and amorphous SiO2 using ultrasonic enhanced cyclonic separation technology, characterized in that, Specifically comprising the following steps: S1. Preparing the slurry: mixing phosphogypsum tailings with water at room temperature, then adding an ultradispersion surfactant and stirring to obtain a slurry; S2. Ultrasonic enhanced separation: placing the slurry under an ultrasonic enhanced probe, and separating by cavitation effect generated by ultrasonic oscillation to make the silica monomers in the tailings depolymerize and obtain a phosphorus-rich and silicon-rich suspension; S3. Cyclone separation: feeding the suspension obtained in step S2 into the feed inlet of an ultrasonic cyclone separator at a certain tangential velocity, and blowing the apatite to the upper layer and out of the upper flow port by controlling the radial flow rate, and the silica is deposited at the bottom by gravity settling and flows out of the lower flow port to obtain an apatite concentrate and a SiO2-rich phase; S4. Vacuum belt separation at the upper flow port: separating the slurry at the upper flow port by vacuum belt filtration to obtain high-grade apatite, and returning the separated solution to step S1 for recycling as the slurry; S5. Vacuum belt separation at the lower flow port: separating the slurry at the lower flow port by vacuum belt filtration to obtain high-grade silica, and returning the separated solution to step S1 for recycling as the slurry.

2. The method according to claim 1, wherein the method is characterized by, In step S1, the phosphogypsum tailings are specifically the tailings obtained after recovering the phosphogypsum and humic acid.

3. The method according to claim 1, wherein the method is characterized by, In step S1, the solid-liquid ratio of the phosphogypsum tailings to water is 1:(10-20) g / mL.

4. The method according to claim 1, wherein the method is characterized by, In step S1, the ultradispersion surfactant is specifically sodium dodecyl sulfate or sodium dodecyl benzene sulfonate, and the addition amount is 0.05%-0.2% of the phosphogypsum tailings based on the mass fraction.

5. The method according to claim 1, wherein the method is characterized in that, In step S2, the ultrasonic oscillation power is controlled at 20-100 W, and the action time of the slurry under the ultrasonic enhanced probe is 5-20 s.

6. The method according to claim 1, wherein the method is characterized by, In step S3, in the ultrasonic cyclone separator, the tangential flow rate of the suspension is 0.1-0.6 m / s, and the radial flow rate is 0.01-0.1 m / s.

7. The method according to claim 1, wherein the method is characterized by, In step S4, the purity of the high-grade apatite is ≥90%.

8. The method according to claim 1, wherein the method is characterized by, In step S5, the purity of the high-grade silica product is ≥95%.

Images