Tantalum-niobium acid production wastewater resource treatment process and device

Abstract

The invention relates to a recycling and utilization treatment process and device for tantalum-niobium acidic wastewater. The tantalum-niobium acidic wastewater enters a dialysis membrane system, sulfuric acid, fluorosilicic acid, fluorotitanic acid and the like in the acidic wastewater are recovered, the recovered acid is reused for production, and the remaining residual liquid wastewater enters a neutralization and precipitation system; the neutralization system neutralizes the acidic wastewater by adding lime milk, the neutralized wastewater enters a sedimentation tank for sedimentation, the clear liquid enters a precision filtering equipment filtering system, the precipitated sludge enters a plate and frame filter press for filtration, the filtration clear liquid and the supernatant liquid in the sedimentation tank are mixed and then enter the precision filtering equipment filtering system, after most of the suspended particles are removed, the clear liquid enters an RO membrane; the RO membrane removes impurities such as inorganic salts and organic matter in the water, and the obtained clear liquid can be used for water-adding dialysis recovery of acid in the dialysis membrane system, and the concentrated water enters an evaporation and crystallization system; the RO concentrated water is subjected to evaporation and crystallization to obtain impurities, which are transported out for treatment, and the evaporation condensate is mixed with the RO clear liquid and returned to the dialysis membrane system for water-adding dialysis recovery of acid.

Description

Technical Field

[0001] The invention relates to a process and a device for recycling and utilizing acidic wastewater resources, and in particular to a process and a device for recycling and utilizing acidic wastewater in the metallurgical industry, and belongs to the field of water treatment. Background Art

[0002] Tantalum (Ta) and niobium (Nb) are rare metals with high melting and boiling points. They look like steel, with a grayish-white luster and dark gray powder. They have the characteristics of air absorption, corrosion resistance, superconductivity, unipolar conductivity and high strength at high temperatures. They are widely used in electronics, precision ceramics and precision glass industries, electro-acoustic and optical devices, cemented carbide, aerospace and electronic energy industries, biomedical engineering, superconducting industry, special steel and other industries.

[0003] In recent years, my country's tantalum-niobium smelting industry has developed rapidly, and its technical level and production capacity have been greatly improved, but its basic metallurgical system has not changed. In the tantalum-niobium smelting process, acid decomposition of ore and HF-H2SO4-MIBK / sec-octanol extraction and separation of tantalum-niobium are generally used. Therefore, a large amount of H2SO4 and NH4 + , HF, H2SiF6, H2TiF6 and Fe 3+ 、Zn 2+ Cr 2+ 、Ni 2+ The total acidity of other metal ion acidic wastewater is about 8-12 equivalents, accounting for about 5% of the tantalum-niobium hydrometallurgical wastewater. The direct discharge of these waste acids into the surrounding environment will inevitably cause environmental pollution, and it is also a waste of resources. Therefore, it is of great significance to continuously optimize the waste acid resource recovery process and effectively improve the utilization rate of waste acid to promote the environmental protection, green and sustainable development of the entire tantalum-niobium industry.

[0004] At present, the waste sulfuric acid resource recovery technology mainly includes evaporation concentration technology, oxidation technology, extraction technology, and crystallization technology. Among them, evaporation concentration and oxidation technology are not suitable for the recovery of waste acid containing inorganic salts such as metal ions; extraction technology can efficiently remove various impurities in waste acid, but most extractants are flammable and explosive organic matter, which poses the risk of secondary pollution and explosion; crystallization technology can recover both sulfuric acid and impurities carried in waste sulfuric acid, but this method is applied to the recovery process of medium and low concentration waste sulfuric acid, which consumes a lot of energy. Therefore, the current domestic method for treating acidic wastewater is lime precipitation. Quicklime is a commonly used agent. It is low in price and easy to obtain, but it has defects such as large amount of sludge and high cost of hazardous waste disposal.

[0005] Therefore, in view of the above problems and the characteristics of tantalum-niobium acid wastewater, the development of a tantalum-niobium acid wastewater resource recovery and utilization treatment process and device has potential application prospects. Summary of the invention

[0006] The purpose of the present invention is to solve the problem that there is no good acid recovery and deep treatment method for tantalum-niobium acid wastewater in the prior art, and propose a resource recovery and utilization treatment process and device for tantalum-niobium acid wastewater.

[0007] The resource treatment process of tantalum-niobium acid production wastewater includes the following steps:

[0008] In the first step, the tantalum-niobium acid wastewater enters the diffusion dialysis treatment to remove sulfuric acid, fluorosilicic acid and fluorotitanic acid;

[0009] Step 2: Add lime to neutralize the dialysate obtained in step 1 to make SO4 2- 、F - Ions generate precipitates; filtration removes the precipitates;

[0010] In the third step, the wastewater obtained in the second step is concentrated by reverse osmosis, and the concentrated solution is crystallized to obtain waste salt.

[0011] In one embodiment, in the step 1, the diffusion dialysis uses an anionic membrane as the selective permeable membrane.

[0012] In one embodiment, in the step 1, the retentate obtained is fed to the acid leaching step in the tantalum-niobium smelting process.

[0013] In one embodiment, the tantalum-niobium acid wastewater contains SO4 2- 400000-900000mg / L, F - 50000-150000mg / L, NH4 + 90-550mg / L, H2SiF612000-40000mg / L, H2TiF620000-80000mg / L, Fe 3+ 15000-55000mg / L, Zn 2+ 1000-5000mg / L, Cr 2+ 100-600mg / L, Ni 2+ 100-600mg / L; acid concentration (Σ H+ ) is around 8~12mol / L.

[0014] In one embodiment, water dialysis is performed during the diffusion dialysis process.

[0015] In one embodiment, in the second step, after adding lime for neutralization, the pH of the wastewater is greater than 10; the neutralization reaction time is 0.5 to 1 hour, and the precipitation time is 0.5 to 1 hour.

[0016] In one embodiment, in the step 2, the filtration is performed using a ceramic membrane filtration device, a PVDF filtration device or a disc tube membrane filtration device, and the average pore size of the filtration is in the range of 0.05 to 0.5 μm.

[0017] In one embodiment, the reverse osmosis membrane filtration pressure is 1.5-2.5 MPa, and the scale inhibitor is added at 2-6 mg / L.

[0018] In one embodiment, the wastewater obtained in step 2 needs to be subjected to adsorption treatment using an ammonium ion adsorbent before entering the third reverse osmosis concentration step.

[0019] In one embodiment, the ammonium ion adsorbent is selected from natural clinoptilolite, K-modified zeolite, Ca-modified zeolite, Mg-modified zeolite or Ba-modified zeolite.

[0020] In one embodiment, the permeate obtained by reverse osmosis concentration is returned to step 1 as a dialysate with water.

[0021] Tantalum niobium acid production wastewater resource treatment device, including:

[0022] Acid waste water tank, used to store acid waste water;

[0023] The diffusion dialysis device is connected to the acid wastewater tank and is used for diffusion dialysis treatment of tantalum-niobium acid production wastewater;

[0024] A neutralization reaction tank, connected to the permeation side of the diffusion dialysis device, for neutralizing the dialysate of the diffusion dialysis device;

[0025] A lime adding port, connected to the neutralization reaction tank, for adding lime to the neutralization reaction tank;

[0026] A solid-liquid separator, connected to the neutralization reaction tank, is used to filter the wastewater after the neutralization reaction to remove the precipitate;

[0027] A reverse osmosis membrane is connected to the permeation side of the solid-liquid separator and is used to filter and desalinate the wastewater after the precipitation is removed;

[0028] The evaporation crystallizer is connected to the concentration side of the reverse osmosis membrane and is used to concentrate and crystallize the retentate of the reverse osmosis membrane.

[0029] In one embodiment, the acidic wastewater tank and the diffusion dialysis device are connected via a pre-filter.

[0030] In one embodiment, it further comprises a water adding device for adding water to the diffusion osmosis device for dialysis.

[0031] In one embodiment, the osmosis side of the reverse osmosis membrane is connected to a water adding device.

[0032] In one embodiment, the device further comprises a retentate tank connected to the retentate side of the diffusion dialysis device.

[0033] In one embodiment, a filter press is further included, connected to the concentration side of the solid-liquid separator, for dehydrating the retained precipitate.

[0034] In one embodiment, the osmosis side of the solid-liquid separator is connected to the water inlet of the reverse osmosis membrane via an adsorbent column; the adsorbent column is filled with an ammonium ion adsorbent.

[0035] In one embodiment, the ammonium ion adsorbent is selected from natural clinoptilolite, K-modified zeolite, Ca-modified zeolite, Mg-modified zeolite or Ba-modified zeolite.

[0036] Beneficial Effects

[0037] Compared with the prior art, the present invention has the following advantages: 1. The present invention realizes the resource recovery and utilization of sulfuric acid, fluorosilicic acid and fluorotitanic acid in tantalum-niobium acidic wastewater, reduces the large amount of waste residue generated by neutralization of acid, and reduces the cost of hazardous waste disposal; 2. After the remaining residual liquid is subjected to neutralization precipitation, precision filtration equipment filtration, reverse osmosis filtration and evaporation crystallization treatment, the clear liquid obtained can be directly reused in the front-end dialysis membrane system process or production process, realizing the recycling of water in the system without wastewater discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a flow chart of the present invention;

[0039] Figure 2 is a diagram of the device of the present invention;

[0040] Among them, 1. Acidic wastewater tank; 2. Pre-filter; 3. Diffusion dialysis device; 4. Water adding device; 5. Retained liquid tank; 6. Neutralization reaction tank; 7. Lime addition port; 8. Filter press; 9. Solid-liquid separator; 10. Adsorbent column; 11. Reverse osmosis membrane; 12. Evaporation crystallizer. DETAILED DESCRIPTION

[0041] The present invention relates to a process and device for recycling and utilizing tantalum-niobium acid wastewater. The process and device mainly include:

[0042] Tantalum and niobium acid wastewater enters the dialysis membrane system to recover sulfuric acid, fluorosilicic acid, fluorotitanic acid, etc. in the acid wastewater. The acid concentration (Σ H+) is about 8~12mol / L, the recovered acid is returned to production, and the remaining residual liquid wastewater enters the neutralization precipitation system; in this step, the tantalum-niobium acid wastewater is mainly dialyzed by diffusion dialysis. An anion membrane, such as an aromatic polyether anion exchange membrane, is used to intercept the main anions such as fluorosilicic acid and fluorotitanic acid, while H+, Zn 2+ NH 4+ 、Ni 2+ The recovered acid mainly contains sulfuric acid, fluorosilicic acid, fluorotitanic acid, etc., which can be used again in the acid leaching step.

[0043] The dialysate obtained in diffusion dialysis mainly contains H+, Zn 2+ NH 4+ 、Ni 2+ etc. cations. In addition, it also contains SO4 2- Through, in the neutralization system, the remaining residual acidic wastewater is neutralized by adding lime milk to generate CaSO4, CaF and other precipitates, and most of the sulfate ions and fluoride ions in the wastewater are removed. The amount of lime milk added is 60~120g / L, and the pH reaches above 10; the neutralization reaction time is 0.5~1h, and the precipitation time is 0.5~1h; the neutralized wastewater enters the sedimentation tank for precipitation, and the supernatant after precipitation enters the precision filtration equipment filtration system, and the precipitated sludge enters the plate and frame filter press for filtration, and the filtration clear liquid and the sedimentation tank supernatant are mixed and then enter the precision filtration equipment filtration system; the precision filtration equipment can be PVDF filtration equipment or disc tube membrane filtration equipment, and the average pore size range of the filtration is 0.05~0.5μm.

[0044] After the filtration system of the dense filtration equipment removes most of the suspended particles, the NH 4+ Adsorption treatment removes most of the NH 4+ After adsorption, the produced water enters the RO membrane filtration system, and the filtered concentrated water returns to the neutralization precipitation system; the RO membrane filtration system removes inorganic salts (mainly heavy metal ions, etc.) and organic impurities in the water, and the obtained clear liquid can be used for water dialysis to recover acid in the dialysis membrane system, and the concentrated water enters the evaporation crystallization system; the RO concentrated water is evaporated and crystallized to obtain impurities, which are transported out for treatment, and the evaporated condensate is mixed with the RO clear liquid and returned to the dialysis membrane system for water dialysis to recover acid. 4+ Ion, NH 4+The presence of leads to an increase in the concentration of positive ions on the interception side of the reverse osmosis, affecting the interception rate of the reverse osmosis membrane for heavy metal ions. Therefore, the problem of affecting the interception rate of heavy metal ions on the reverse osmosis surface is eliminated after the adsorption bed treatment, and the purity of the reverse osmosis water is improved. The ammonium ion adsorbent is selected from natural clinoptilolite, K modified zeolite, Ca modified zeolite, Mg modified zeolite or Ba modified zeolite. The reverse osmosis membrane filtration pressure used is 1.5~2.5MPa; in one embodiment, 2~6mg / L of scale inhibitor needs to be added to the reverse osmosis inlet water.

[0045] Based on the above process, the device provided by the present invention is as follows Figure 2 As shown, including:

[0046] Acid waste water tank 1, used for storing acid waste water;

[0047] The diffusion dialysis device 3 is connected to the acid wastewater tank 1 and is used for diffusion dialysis treatment of tantalum-niobium acid production wastewater;

[0048] A neutralization reaction tank 6, connected to the permeation side of the diffusion dialysis device 3, for neutralizing the dialysate of the diffusion dialysis device 3;

[0049] A lime adding port 7 is connected to the neutralization reaction tank 6 and is used to add lime to the neutralization reaction tank 6;

[0050] The solid-liquid separator 9 is connected to the neutralization reaction tank 6 and is used to filter the wastewater after the neutralization reaction to remove the precipitate;

[0051] The reverse osmosis membrane 11 is connected to the permeation side of the solid-liquid separator 9 and is used to filter and desalinate the wastewater after the precipitation is removed;

[0052] The evaporation crystallizer 12 is connected to the concentration side of the reverse osmosis membrane 11 and is used to concentrate and crystallize the retentate of the reverse osmosis membrane 11 .

[0053] Among them, 1. Acidic wastewater tank; 2. Pre-filter; 3. Diffusion dialysis device; 4. Water adding device; 5. Retained liquid tank; 6. Neutralization reaction tank; 7. Lime addition port; 8. Filter press; 9. Solid-liquid separator; 10. Adsorbent column; 11. Reverse osmosis membrane; 12. Evaporation crystallizer.

[0054] In one embodiment, the acidic wastewater tank 1 and the diffusion dialysis device 3 are connected via a pre-filter 2 .

[0055] In one embodiment, a water adding device 4 is further included, for adding water to the diffusion osmosis device 3 for dialysis.

[0056] In one embodiment, the permeation side of the reverse osmosis membrane 11 is connected to the water adding device 4 .

[0057] In one embodiment, the device further comprises a retentate tank 5 connected to the retentate side of the diffusion dialysis device 3 .

[0058] In one embodiment, a filter press 8 is further included, which is connected to the concentration side of the solid-liquid separator 9 and is used to dehydrate the retained precipitate.

[0059] Example 1

[0060] Acidic wastewater acid concentration (Σ H+ ) at 10.4mol / L, SO4 2- :457.5g / L,F - :112.5g / L, Si: 14.5g / L, Ti: 24.06g / L, Fe: 20g / L, NH 4+ 200mg / L, Zn 2+ 1400mg / L, Cr 2+ 320mg / L, Ni 2+ 260mg / L. Pump tantalum-niobium acid wastewater into the dialysis membrane acid inlet tank, turn on the acid inlet pump and the water inlet pump, adjust the acid inlet flow rate to 21.2L / h and the water inlet flow rate to 22L / h, and operate the dialysis membrane system. The remaining residual liquid is pumped into the neutralization reaction tank, and lime milk is automatically added for neutralization reaction. The pH is adjusted to 10, and the reaction is stirred for 30 minutes. It is pumped into the sedimentation tank for precipitation. After the sedimentation residence time is 30 minutes, it overflows to the ceramic membrane filtration equipment for filtration to remove suspended impurities; a 50nm ceramic membrane is used for filtration, and the filtration pressure is 0.3MPa. The concentrated water returns to the sedimentation tank to remove suspended particles. The filtered water enters the reverse osmosis membrane system for filtration to remove inorganic salts, organic matter and other impurities. No scale inhibitor is added to the inlet water. The filtration pressure of the reverse osmosis membrane system is 1.5MPa. The reverse osmosis concentrated water enters the evaporation crystallization device for further concentration and crystallization into salt; the reverse osmosis filtrate and the evaporation condensate are discharged into the final clean water tank, and the final clean water is reused for water dialysis in the front-end dialysis membrane system;

[0061] Example 2

[0062] Acidic wastewater acid concentration (Σ H+ ) at 10.4mol / L, SO4 2- :457.5g / L,F - :112.5g / L, Si: 14.5g / L, Ti: 24.06g / L, Fe: 20g / L, NH 4+ 330mg / L, Zn 2+ 1600mg / L, Cr 2+ 330mg / L, Ni 2+270mg / L. Pump the tantalum-niobium acid wastewater into the dialysis membrane acid inlet tank, start the acid inlet pump and the water inlet pump, adjust the acid inlet flow rate to 20.8L / h and the water inlet flow rate to 23.6L / h, and operate the dialysis membrane system. The remaining residual liquid is pumped into the neutralization reaction tank, and lime milk is automatically added for neutralization reaction. The pH is adjusted to 11, stirred for reaction for 30 minutes, and then pumped into the sedimentation tank for precipitation. After the sedimentation residence time is 30 minutes, it overflows to the ceramic membrane filtration equipment for filtration to remove suspended impurities; a 50nm ceramic membrane is used for filtration, and the filtration pressure is 0.3MPa. The concentrated water returns to the sedimentation tank to remove suspended particles, and the filtered water enters the reverse osmosis membrane system for filtration to remove inorganic salts, organic matter and other impurities. No scale inhibitor is added to the inlet water, and the filtration pressure of the reverse osmosis membrane system is 1.5MPa. The reverse osmosis concentrated water enters the evaporation crystallization device for further concentration and crystallization into salt; the reverse osmosis filtrate and the evaporation condensate are discharged into the final clean water tank, and the clean water TDS is 241mg / L. The final clean water is reused for water dialysis in the front-end dialysis membrane system;

[0063] Example 3

[0064] Acidic wastewater acid concentration (Σ H+ ) at 10.4mol / L, SO4 2- :457.5g / L,F - :112.5g / L, Si: 14.5g / L, Ti: 24.06g / L, Fe: 20g / L, NH 4+ 270mg / L, Zn 2+ 1700mg / L, Cr 2+ 260mg / L, Ni 2+ 290mg / L. Tantalum-niobium acid wastewater is pumped into the dialysis membrane acid inlet tank, the acid inlet pump and water inlet pump are turned on, the acid inlet flow rate is adjusted to 24L / h and the water inlet flow rate is adjusted to 26.2L / h, and the dialysis membrane system is operated. The remaining residual liquid is pumped into the neutralization reaction tank, and lime milk is automatically added for neutralization reaction, adjusted to a pH of 12 or above, stirred for reaction for 30 minutes, and pumped into the sedimentation tank for precipitation. After the sedimentation residence time is 30 minutes, it overflows to the ceramic membrane filtration equipment for ceramic membrane filtration; 50nm ceramic membrane filtration is used, and the filtration pressure is 0.3MPa. The concentrated water returns to the sedimentation tank to remove suspended particles, and the filtered water enters the reverse osmosis membrane system for filtration to remove inorganic salts, organic matter and other impurities. No scale inhibitor is added to the inlet water, and the filtration pressure of the reverse osmosis membrane system is 1.5MPa. The reverse osmosis concentrated water enters the evaporation crystallization device for further concentration and crystallization into salt; the reverse osmosis filtrate and the evaporation condensate are discharged into the final clean water tank, and the final clean water is obtained and reused in the front-end dialysis membrane system or production process.

[0065] Example 4

[0066] The difference from Example 1 is that the produced water entering the reverse osmosis membrane is treated with natural clinoptilolite NH4+ For adsorption treatment.

[0067] Acidic wastewater acid concentration (Σ H+ ) at 10.4mol / L, SO4 2- :457.5g / L,F - :112.5g / L, Si: 14.5g / L, Ti: 24.06g / L, Fe: 20g / L, NH 4+ 200mg / L, Zn 2+ 1400mg / L, Cr 2+ 320mg / L, Ni 2+ 260mg / L. Pump the tantalum-niobium acid wastewater into the dialysis membrane acid inlet tank, start the acid inlet pump and the water inlet pump, adjust the acid inlet flow rate to 21.2L / h and the water inlet flow rate to 22L / h, and operate the dialysis membrane system. The remaining residual liquid is pumped into the neutralization reaction tank, and lime milk is automatically added for neutralization reaction. The pH is adjusted to 10, stirred for reaction for 30 minutes, and then pumped into the sedimentation tank for precipitation. After the sedimentation residence time is 30 minutes, it overflows to the ceramic membrane filtration equipment for filtration to remove suspended impurities; a 50nm ceramic membrane is used for filtration, and the filtration pressure is 0.3MPa. The concentrated water returns to the sedimentation tank to remove suspended particles. The filtered water is adsorbed in an adsorption column filled with natural clinoptilolite. The adsorbed water enters the reverse osmosis membrane system for filtration to remove inorganic salts, organic matter and other impurities. No scale inhibitor is added to the inlet water. The filtration pressure of the reverse osmosis membrane system is 1.5MPa. The reverse osmosis concentrated water enters the evaporation crystallization device for further concentration and crystallization into salt; the reverse osmosis filtrate and the evaporation condensate are discharged into the final clean water tank, and the final clean water is reused for water dialysis in the front-end dialysis membrane system.

[0068] Example 5

[0069] The difference from Example 1 is that the produced water entering the reverse osmosis membrane is treated with natural clinoptilolite NH 4+ For adsorption treatment.

[0070] Acidic wastewater acid concentration (Σ H+ ) at 10.4mol / L, SO4 2- :457.5g / L,F - :112.5g / L, Si: 14.5g / L, Ti: 24.06g / L, Fe: 20g / L, NH 4+ 330mg / L, Zn 2+ 1600mg / L, Cr 2+ 330mg / L, Ni 2+270mg / L. Pump the tantalum-niobium acid wastewater into the dialysis membrane acid inlet tank, start the acid inlet pump and the water inlet pump, adjust the acid inlet flow rate to 20.8L / h and the water inlet flow rate to 23.6L / h, and operate the dialysis membrane system. The remaining residual liquid is pumped into the neutralization reaction tank, and lime milk is automatically added for neutralization reaction. The pH is adjusted to 11, and the reaction is stirred for 30 minutes. It is pumped into the sedimentation tank for precipitation. After the sedimentation residence time is 30 minutes, it overflows to the ceramic membrane filtration equipment for filtration to remove suspended impurities; a 50nm ceramic membrane is used for filtration, and the filtration pressure is 0.3MPa. The concentrated water returns to the sedimentation tank to remove suspended particles. The filtered water is adsorbed in an adsorption column filled with natural clinoptilolite. The adsorbed water enters the reverse osmosis membrane system for filtration to remove inorganic salts, organic matter and other impurities. No scale inhibitor is added to the inlet water. The filtration pressure of the reverse osmosis membrane system is 1.5MPa. The reverse osmosis concentrated water enters the evaporation crystallization device for further concentration and crystallization into salt; the reverse osmosis filtrate and the evaporation condensate are discharged into the final clean water tank, and the clean water TDS is 241mg / L. The final clean water is recycled for water dialysis in the front-end dialysis membrane system.

[0071] Example 6

[0072] The difference from Example 1 is that the produced water entering the reverse osmosis membrane is treated with natural clinoptilolite NH 4+ For adsorption treatment.

[0073] Acidic wastewater acid concentration (Σ H+ ) at 10.4mol / L, SO4 2- :457.5g / L,F - :112.5g / L, Si: 14.5g / L, Ti: 24.06g / L, Fe: 20g / L, NH 4+ 270mg / L, Zn 2+ 1700mg / L, Cr 2+ 260mg / L, Ni 2+290mg / L. Pump the tantalum-niobium acid wastewater into the dialysis membrane acid inlet tank, start the acid inlet pump and the water inlet pump, adjust the acid inlet flow rate to 24L / h and the water inlet flow rate to 26.2L / h, and operate the dialysis membrane system. The remaining residual liquid is pumped into the neutralization reaction tank, and lime milk is automatically added for neutralization reaction. The pH is adjusted to above 12, stirred for reaction for 30 minutes, and then pumped into the sedimentation tank for precipitation. After the sedimentation residence time is 30 minutes, it overflows to the ceramic membrane filtration equipment for ceramic membrane filtration; a 50nm ceramic membrane is used for filtration, and the filtration pressure is 0.3MPa. The concentrated water returns to the sedimentation tank to remove suspended particles. The filtered water enters the adsorption column filled with natural clinoptilolite for adsorption treatment. The adsorbed water enters the reverse osmosis membrane system for filtration to remove inorganic salts, organic matter and other impurities. No scale inhibitor is added to the inlet water. The filtration pressure of the reverse osmosis membrane system is 1.5MPa. The reverse osmosis concentrated water enters the evaporation crystallization device for further concentration and crystallization into salt; the reverse osmosis filtrate and the evaporation condensate are discharged into the final clean water tank, and the final clean water is obtained and reused in the front-end dialysis membrane system or production process.

[0074]

[0075] The operating parameters in the treatment steps in the above embodiment are shown in the table above. It can be seen from the table that the acid solution can be recovered through diffusion and permeation treatment and can be used again in the acid leaching treatment step; after precipitation treatment, F in the wastewater can be removed. - ions, and obtain CaSO4 gypsum; then through adsorption and reverse osmosis treatment in turn, low conductivity water is obtained, which can be reused; after adsorption treatment, NH 4+ , avoiding its impact on the retention of heavy metal ions and improving the retention rate of heavy metal ions.

Claims

1. Tantalum-niobium acid production wastewater resource treatment process, characterized in that: The steps include: In the first step, the tantalum-niobium acid production wastewater enters the diffusion dialysis treatment to remove sulfuric acid, fluorosilicic acid and fluorotitanic acid; Step 2: Add lime to neutralize the dialysate obtained in step 1 to make SO4 2- 、F - Ions generate precipitation; Filter to remove the precipitate; Step 3, the wastewater obtained in step 2 needs to be treated by adsorption with an ammonium ion adsorbent and then enter reverse osmosis concentration; after the concentrated solution is crystallized, waste salt is obtained; the ammonium ion adsorbent is selected from natural clinoptilolite, K modified zeolite, Ca modified zeolite, Mg modified zeolite or Ba modified zeolite; In the step 1, water is added for dialysis during the diffusion dialysis process, and an anionic membrane is used as a selective permeable membrane; in the step 1, the retentate obtained is sent to the acid leaching step in the tantalum-niobium smelting process; In the second step, after adding lime for neutralization, the pH of the wastewater is greater than 10; the neutralization reaction time is 0.5 to 1 hour, and the precipitation time is 0.5 to 1 hour; the filtration adopts a ceramic membrane filtration device, a PVDF filtration device or a disc tube membrane filtration device, and the average pore size range of the filtration is 0.05 to 0.5 μm.

2. The resource treatment process for tantalum-niobium acid production wastewater according to claim 1 is characterized in that: The reverse osmosis concentration pressure is 1.5~2.5MPa, and the scale inhibitor is added at 2~6mg / L.

3. The resource treatment process for tantalum-niobium acid production wastewater according to claim 1 is characterized in that: The permeate obtained by the reverse osmosis concentration is returned to step 1 as a dialysate with water.

4. The resource treatment process for tantalum-niobium acid production wastewater according to claim 1 is characterized in that: Tantalum niobium acid production wastewater contains SO4 2- 400000-900000mg / L, F - 50000-150000mg / L, NH4 + 90-550mg / L, H2SiF61 2000-40000mg / L, H2TiF6 20000-80000mg / L, Fe 3+ 15000-55000mg / L, Zn 2+ 1000-5000mg / L, Cr 2+ 100-600mg / L, Ni 2+ 100-600mg / L; acid concentration is 8~12mol / L.

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