Method for preparing high-purity ammonium metavanadate by deep manganese removal

Abstract

The application provides a method for preparing high-purity ammonium metavanadate by deeply removing manganese, which comprises the following steps: dissolving alkali and flocculating agent in water, and heating the solution to 70-90 DEG C; adding manganese-containing vanadium raw material into the solution, and adjusting the pH of the solution to 8-10 by alkali; adding oxidant into the solution, heating to 70-90 DEG C, and reacting for 1-10 hours to obtain slurry solution and flocculating residue; diluting the slurry solution with water to the V2O5 concentration of 50-90 g / L, adjusting the color of the solution to light yellow by adding vanadium-containing waste electrolyte, controlling the pH of the solution to 7.0-8.0, adding ammonium salt to carry out vanadium precipitation, and preparing high-purity ammonium metavanadate solid. 2+ The method can effectively fix the manganese in the manganese-containing vanadium raw material in the flocculating residue, realize vanadium-manganese separation, and completely solve the problems of Mn The method also prepares high-purity ammonium metavanadate, and widens the selection of raw materials for high-purity vanadium preparation.

Description

Technical Field

[0001] This invention relates to a technology for preparing high-purity ammonium metavanadate, and more particularly to a method for preparing high-purity ammonium metavanadate by deep manganese removal. Background Technology

[0002] Chinese patent CN193022454A discloses a method for removing manganese from acidic vanadium precipitation wastewater. The main process includes: adjusting the pH value of the acidic vanadium precipitation wastewater to 5-7, adding ammonium oxalate, and then filtering to obtain manganese oxalate precipitate and supernatant. The supernatant contains less than 0.05 g / L of Mn. 2+ .

[0003] The above technical solution has the following problems: 1. Using soluble ammonium oxalate to precipitate manganese ions also precipitates calcium and magnesium ions in the solution, forming calcium oxalate and magnesium oxalate. This results in low purity of manganese in the precipitate, which is not conducive to the recovery and utilization of manganese. Furthermore, the removal of manganese is incomplete, and the concentration of manganese ions in the supernatant is high. 2. Precipitating manganese ions with ammonium oxalate will introduce a large amount of ammonium ions, causing ammonia nitrogen in wastewater to exceed the standard; 3. This technical solution involves adding ammonium oxalate under acidic conditions. The reaction process will generate oxalic acid, which will increase the organic matter content in the water and cause the COD to fail to meet the standards.

[0004] Chinese patent CN109336292A discloses a method for treating manganese-containing wastewater. The main process includes: collecting manganese-containing wastewater and removing suspended and floating solids from the wastewater; placing the manganese-containing wastewater from the wastewater tank into a dosing tank, adding sodium hydroxide to adjust the pH value to 9.60±0.10, stirring for 5-10 minutes, adding an oxidant, stirring for 20-30 minutes, and then entering an aeration tank for full aeration and reaction to generate manganese metahydride (MnO(OH)2); overflowing the reaction effluent from the aeration tank into a coagulation tank, adding flocculant, and stirring for 10-20 minutes; placing the effluent from the coagulation reaction tank into a sedimentation tank, letting it stand for a period of time, and allowing the manganese metahydride generated in the wastewater to fully flocculate and precipitate; the manganese metahydride precipitate generated in the sedimentation tank, and the sludge is transported to a sludge thickening tank for thickening treatment, and then pumped into a filter press for filter pressing treatment. The manganese metahydride contained in the sludge is filtered into sludge cake for recycling and reuse in production, and the remaining liquid after filtration is returned to the wastewater tank for recycling treatment.

[0005] 1. The above technical solution has the following problems: The current technology involves many steps, a long process, and is quite complex, making it impossible to remove manganese to a low level in one go.

[0006] 2. This technical solution is only applicable to wastewater with a manganese content of 50 mg / L. It does not cover the treatment of wastewater with higher manganese content and is not suitable for widespread application.

[0007] 3. The sludge cake produced during the manganese removal process cannot be recycled. It not only consumes a large amount of flocculant, but also produces a large amount of sludge cake, which requires secondary treatment and increases the cost of wastewater treatment.

[0008] There has been no good method for separating vanadium and manganese in manganese-vanadium raw materials. Manganese in vanadium raw materials does not exist in the form of stable compounds, but mostly in the form of divalent manganese ions. If only flocculation slag is used to adsorb manganese ions in manganese-vanadium raw materials, although 80% of the manganese can be removed, the loss of vanadium is relatively large. Moreover, the manganese will be re-dissolved when vanadium is extracted from the flocculation slag in the subsequent process, and the manganese cannot be completely removed. The flocculation slag adsorption method cannot completely solve the problem of vanadium-manganese separation.

[0009] The above methods cannot completely remove manganese from manganese-vanadium-containing raw materials. During wastewater treatment, we found that manganese and vanadium are in competition, significantly impacting the resin's adsorption of vanadium. This leads to a decrease in the resin's adsorption capacity, a significantly shortened resin saturation time, and manganese ions forming precipitates within the resin after adsorption, making them virtually impossible to precipitate. This results in resin poisoning, causing the resin to gradually lose its vanadium adsorption capacity, potentially leading to the collapse of the water treatment system. Therefore, for manganese-containing vanadium raw materials, the inability to completely separate vanadium and manganese significantly limits the selection of vanadium raw materials and hinders the competitiveness of vanadium batteries. Summary of the Invention

[0010] The purpose of this invention is to address the problem that manganese ions can easily cause resin poisoning and paralyze water treatment systems during the traditional manganese removal process of manganese-vanadium raw materials. This invention proposes a method for deep manganese removal to prepare high-purity ammonium metavanadate. This method can effectively and stably fix the manganese in the manganese-vanadium raw materials in the flocculant through precipitation, completely solving the impact of Mn on the wastewater system. Simultaneously, this method also prepares high-purity ammonium metavanadate, broadening the selection of raw materials for vanadium batteries.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is: a method for preparing high-purity ammonium metavanadate (AMV) through deep manganese removal, comprising the following steps: Step 1: Dissolve the alkali and flocculant in water, and heat the solution to 70℃~90℃; Step 2: Add manganese-vanadium-containing raw materials to the solution and adjust the pH to 8-10 with alkali to dissolve the vanadium and manganese in the raw materials into the solution; Step 3: Add oxidant to the solution, heat to 70℃~90℃, react for 1~10h, filter to obtain slurry and flocculent residue, add water to the flocculent residue to adjust the slurry and return to Step 1 to replace the flocculant for recycling; Step 4: Dilute the slurry with water to a V2O5 concentration of 50-90 g / L, add vanadium-containing waste electrolyte to adjust the solution color to light yellow, control the solution pH to 7.0-8.0, add ammonium salt to precipitate vanadium, and obtain high-purity AMV solid.

[0012] Further, in step 1, the amount of alkali added is 50~100g / L, and the amount of flocculant added is 1~100g / L. Preferably, the amount of alkali added is 60~100g / L, and the amount of flocculant added is 30~80g / L.

[0013] Furthermore, in step 2, the pH is adjusted to 8-10 with alkali. When the pH is above 8, the removal rate of manganese increases with the increase of pH value. However, the amount of alkali used increases with the increase of pH value, and the production cost also increases. Therefore, the optimal pH range is limited to 8-10.

[0014] This invention adds manganese-vanadium-containing raw materials to a solution containing alkali and flocculant, rather than adding alkali and flocculant to a solution in which manganese-vanadium-containing raw materials are dissolved, because: Firstly, under strongly alkaline conditions, flocculant can dissolve in large quantities. After the addition of vanadium raw materials, as hydroxide ions in the solution are continuously consumed, the pH of the solution decreases, and the ions will precipitate, which can better coat manganese and other impurity ions, thus aiding in manganese removal. Secondly, from a production operation perspective, the first flocculant can be directly added to the manganese removal reactor after the addition of vanadium raw materials. After manganese removal is completed, the flocculated residue will be discharged. Due to the high viscosity of the flocculated residue, discharge and refeeding are difficult. The discharged flocculated residue cannot be recycled, the flocculant can only be used once, and the flocculated residue will carry a large amount of vanadium, seriously affecting the vanadium yield. We can filter the flocculated residue through a pressure filter and discharge it into a slurry tank. Water is added to the flocculated residue to form a slurry, which is then pumped into a manganese removal reactor. Subsequently, alkali and vanadium raw materials are added sequentially, followed by an oxidant, creating a continuous cycle that facilitates production. This feeding sequence not only effectively removes manganese but also improves production efficiency, reduces production costs, and minimizes labor. Therefore, adding manganese-vanadium-containing raw materials to a solution containing alkali and flocculant is more in line with the realities of large-scale industrial production.

[0015] Further, the flocculant in step 1 is one or more of zinc sulfate, zinc chloride, polyaluminum chloride, magnesium sulfate, aluminum sulfate, sodium aluminate, alumina, ferrous sulfate, and aluminum hydroxide, preferably zinc sulfate, aluminum hydroxide, polyaluminum chloride, aluminum sulfate, and sodium aluminate.

[0016] Further, the alkali mentioned in step 1 is one or more of sodium carbonate, potassium carbonate, potassium hydroxide, and sodium hydroxide.

[0017] Further, the solution from step 1 is heated to 80-90°C.

[0018] Furthermore, the manganese content in the manganese-vanadium raw material described in step 2 is 0.05wt%~1.0wt%, preferably 0.05wt%~0.6wt%.

[0019] Further, in step 2, manganese-vanadium-containing raw materials are added to the solution to make the Mn concentration in the solution 0.1~1.8g / L, preferably 0.1~1.4g / L.

[0020] Further, in step 2, manganese-vanadium raw materials are added to the solution to make the concentration of manganese-vanadium raw materials in the solution 120~250g / L, preferably 150~250g / L.

[0021] Further, the manganese-vanadium raw material mentioned in step 2 is one or more of the following: manganese-containing ammonium polyvanadate (APV), manganese-containing ammonium metavanadate (AMV), manganese-containing red vanadium, manganese-containing sodium ammonium vanadate, and manganese-containing vanadium pentoxide (V2O5).

[0022] Further, the alkali mentioned in step 2 is one or more of sodium carbonate, sodium bicarbonate, sodium aluminate, potassium carbonate, potassium hydroxide, and sodium hydroxide.

[0023] Further, in step 2, the pH of the solution is adjusted to 9-10.

[0024] Further, in step 3, the temperature is increased to 80℃~90℃, and the reaction is carried out for 2~3 hours.

[0025] Further, the alkali mentioned in step 3 is one or more of sodium carbonate, sodium bicarbonate, sodium aluminate, potassium carbonate, potassium hydroxide, and sodium hydroxide.

[0026] Furthermore, the amount of oxidant added in step 3 is 5 to 30 times the mass of Mn in the solution, preferably 10 to 20 times.

[0027] Further, the oxidant in step 3 is one or more selected from air, oxygen, ozone, perchloric acid, sodium chlorate, potassium chlorate, potassium permanganate, hydrogen peroxide, ammonium persulfate, ammonium chloride, and sodium persulfate. Sodium persulfate is preferred.

[0028] Further, in step 4, the slurry is diluted with water to a V2O5 concentration of 70-90 g / L.

[0029] Furthermore, the vanadium-containing waste electrolyte in step 4 mainly contains H + VO2 + VO 2+ , or H + V 3+ VO 2+ H in vanadium-containing waste electrolyte + It can neutralize OH in the solution (slurry). - VO 2+ or V 3+ This method can consume excess oxidant, not only preventing residual oxidant but also enabling the recovery of waste vanadium electrolyte. The amount of vanadium-containing waste electrolyte added should be sufficient to consume excess oxidant.

[0030] Furthermore, the vanadium-containing waste electrolyte includes, but is not limited to, waste electrolyte from vanadium redox flow batteries. The waste electrolyte from vanadium redox flow batteries is the discarded electrolyte that becomes unusable due to valence imbalance or deviation caused by battery operation. Its main components include, but are not limited to, one or more of the following: water, vanadium oxychloride (VOCl2), vanadium sulfate (V2(SO4)3), vanadium oxysulfate (VOSO4), vanadium trichloride (VCl3), sulfuric acid (H2SO4), and hydrochloric acid (HCl).

[0031] Further, in step 4, the pH is adjusted to 7.0-8.0 by adding caustic soda or sulfuric acid.

[0032] Further, the ammonium salt mentioned in step 4 is one or more of ammonium sulfate, ammonium chloride, ammonium bisulfate, ammonium nitrate, ammonium carbonate, and ammonium bicarbonate.

[0033] Furthermore, in step 4, the amount of ammonium salt added is 1.0 to 3.0 times the mass of V2O5 in the solution, preferably 1.5 to 2 times.

[0034] This invention provides a method for deep manganese removal to prepare high-purity ammonium metavanadate (AMV), which has the following advantages compared with existing technologies: 1) Most of the manganese in manganese-vanadium raw materials is divalent manganese. Under high temperature conditions, it is oxidized to tetravalent manganese by an oxidant (such as sodium persulfate), and a stable MnO2 precipitate is formed under alkaline conditions. Under the adsorption of flocculant, MnO2 precipitates in the flocculant residue, and finally the separation of vanadium and manganese is achieved.

[0035] 2) This invention employs a specific material addition sequence: first, add the flocculant; then, add the manganese-containing raw material; and finally, add the oxidant. The flocculant or flocculated residue added first is in excess, which not only helps to better coat manganese and other impurity ions, ensuring the manganese removal effect, but also ensures the recycling of the flocculated residue. Then, the manganese-vanadium-containing raw material is added; the alkali in the solution will fully dissolve the vanadium and manganese ions. Adding the oxidant last ensures that the oxidant fully reacts with the manganese ions in the solution, guaranteeing the manganese ion removal rate. If the oxidant is added at the very beginning or before adding the manganese-vanadium-containing raw material, the oxidant will react chemically with other ions first, thus affecting the chemical reaction with manganese ions and leading to a decrease in the manganese ion removal rate.

[0036] This invention returns the flocculated residue to replace the flocculant for recycling, which not only saves the amount of flocculant used, but also effectively reduces vanadium loss (vanadium is carried in the flocculated residue). After the failed flocculated residue is washed back, the total vanadium yield of the vanadium raw material is over 99.5%.

[0037] 3) This invention is applicable to manganese-vanadium raw materials, especially high-manganese vanadium raw materials. The vanadium raw material is dissolved in the solution, and the Mn concentration can reach 0.1~1.8g / L. It is especially applicable to manganese-containing APV and / or manganese-containing AMV.

[0038] 4) The manganese removal temperature of this invention is 70~90℃. Under this temperature condition, it is beneficial to reduce the manganese concentration to the qualified concentration (below 5mg / L) in one go. Moreover, within this temperature range, as the temperature increases, the rate of the oxidation-reduction reaction accelerates, and the manganese removal rate increases. If the temperature is too low (such as below 70℃), the manganese removal effect is poor, and if the temperature is too high (such as above 90℃), the cost of steam consumption is high.

[0039] 5) This invention fixes manganese in the flocculant, effectively solving the problem of manganese ions affecting the resin, eliminating the risk of resin poisoning, and greatly improving the service life of the resin.

[0040] 6) This invention can recycle vanadium-containing waste electrolyte, realize the clean utilization of vanadium, provide a new idea for vanadium electrolyte recycling, and can convert waste electrolyte back into vanadium chemicals, turning waste into treasure.

[0041] 7) The high-purity AMV prepared by this invention has a purity greater than 99.90%, which can be further used to prepare high-purity vanadium chemicals and vanadium electrolytes. Vanadium electrolytes are an important component of vanadium batteries, further broadening the applicable scope of vanadium raw materials.

[0042] Unless otherwise specified, "%" in this invention refers to mass percentage content. Attached Figure Description

[0043] Figure 1 This is a flowchart of the method for preparing high-purity ammonium metavanadate by deep manganese removal according to the present invention. Detailed Implementation

[0044] The present invention will be further described below with reference to the embodiments: Examples 1-5 This embodiment discloses a method for preparing high-purity ammonium metavanadate (AMV) through deep manganese removal, comprising the following steps: Step 1: Add 35g of caustic soda flakes and 15g of sodium aluminate to 500ml of water, and heat to T1℃; Step 2: Add 125g of manganese-containing APV, add 5g of sodium carbonate to adjust pH=9, and stir until the manganese-containing APV is completely dissolved; the main components and contents of manganese-containing APV are shown in Table 1. Step 3: Add 0.59g of potassium permanganate (containing 10 times the mass of the manganese vanadium raw material Mn), heat to T2℃, stir and react for 2 hours, then filter to obtain 550ml of slurry and flocculated residue. All the obtained flocculated residue is returned to Step 1 to replace sodium aluminate for 4 cycles. Specific reaction parameters are shown in Table 2. Step 4: Take 500ml of the slurry solution and dilute it with water to a V2O5 concentration of 80g / L. Add 9.5ml of vanadium-containing waste electrolyte (VO2O5). 2+ =0.56mol / L, V3+ =0.16mol / L, H + =3.1mol / L) Adjust the solution color to pale yellow, control the solution pH to 7.5, add 1.5 times the mass of V2O5 ammonium sulfate to precipitate vanadium, and obtain high-purity AMV solid.

[0045] Table 1. Components and content of manganese-containing APV <![CDATA[V2O5(wt%)]]> K (wt%) Na (wt%) Cr (wt%) Mn (wt%) <![CDATA[H2O(wt%)]]> 89.48 0.1178 0.0059 0.0058 0.0661 28.25 Table 2 Manganese Removal Reaction Parameters Example ml of water Step 1: Sodium hydroxide tablets (g) Step 2 Sodium carbonate g flocculants <![CDATA[T1℃]]> Manganese-containing APVg Potassium permanganate g <![CDATA[T2℃]]> Slurry 1 500 35 5 15g sodium aluminate 70 125 0.59 90 Slurry 1 2 500 27 5 wet flocculation residue 70 125 0.59 90 Slurry 2 3 500 27 4 wet flocculation residue 70 125 0.59 80 Slurry 3 4 500 27 6 wet flocculation residue 70 125 0.59 70 Slurry 4 5 500 27 5 wet flocculation residue 70 125 0.59 70 Slurry 5 The test data of the slurry in Examples 1-5 are shown in Table 3.

[0046] Table 3 Manganese removal rate and vanadium loss in the pulping process Slurry Number of cycles <![CDATA[V2O5(g / L)]]> Mn (g / L) before manganese removal Mn (g / L) in slurry Mn ratio <![CDATA[V2O5 loss rate]]> Slurry 1 0 125.00 0.1186 0.00026 99.29% 14.33% Slurry 2 1 147.35 0.1186 0.00011 99.90% -0.98% Slurry 3 2 142.88 0.1186 0.00011 99.90% 2.08% Slurry 4 3 148.64 0.1186 0.00016 99.85% -1.87% Slurry 5 4 145.99 0.1186 0.00017 99.84% 1.80% As shown in Table 3, the manganese removal effect of sodium aluminate or flocculant circulation is relatively good. The manganese content in the slurry is between 0.11 and 0.26 mg / L, and the manganese removal rate is between 99.29% and 99.90%. The initial V2O5 loss rate is relatively large at 14.33%, and the maximum V2O5 loss rate after circulation is 2.08%. In subsequent circulation processes, V2O5 basically reaches dynamic equilibrium. Only the first batch of flocculant carries a relatively large amount of vanadium. After backwashing, the total vanadium recovery rate of the raw material is 99.85%.

[0047] Table 4 High-purity AMV detection data Example <![CDATA[V2O5(wt%)]]> K (wt%) Na (wt%) Fe (wt%) Cr (wt%) Mn (wt%) Si (wt%) 1 77.72 0.0062 0.0040 0.0003 0.0006 0.0000 0.0085 2 77.70 0.0071 0.0036 0.0005 0.0005 0.0000 0.0096 3 77.73 0.0068 0.0041 0.0002 0.0005 0.0000 0.0092 4 77.71 0.0065 0.0026 0.0003 0.0003 0.0000 0.091 5 77.73 0.0068 0.0038 0.0001 0.0004 0.0000 0.0084 As can be seen from Table 4, the high-purity AMV prepared after manganese removal has zero Mn content and the content of other impurities is less than 100 ppm. The purity of AMV is greater than 99.90%, and it can be used for the production of high-purity vanadium and vanadium electrolyte.

[0048] Examples 6-10 This embodiment discloses a method for preparing high-purity ammonium metavanadate (AMV) through deep manganese removal, comprising the following steps: Step 1: Add 47g of caustic soda flakes, 35g of aluminum sulfate, and 5g of aluminum hydroxide to 500ml of water, and heat to 90℃; Step 2: Add 100g of manganese-containing AMV and 2g of potassium hydroxide to adjust the pH to 10; the main components and contents of manganese-containing AMV are shown in Table 5.

[0049] Step 3: Add 7.78g of sodium persulfate (20 times the mass of raw material Mn), heat to 90℃, react for 3 hours, and filter to obtain 500ml of slurry and flocculated residue. The flocculated residue is returned to Step 1 to replace aluminum sulfate and aluminum hydroxide for 4 cycles. Specific reaction parameters are shown in Table 6.

[0050] Step 4: Take 500ml of the slurry solution and dilute it with water to a V2O5 concentration of 90g / L. Add 5.3ml of vanadium-containing waste electrolyte (VO2O5). 2+ =0.71mol / L, V 3+ =0.62mol / L, H + =7.2mol / L) Adjust the solution color to pale yellow, control the solution pH to 8.0, add 2.0 times the mass of ammonium chloride of V2O5 to precipitate vanadium, and obtain high-purity AMV solid.

[0051] Table 5. Components and content of manganese-containing AMV <![CDATA[V2O5(wt%)]]> K (wt%) Na (wt%) Cr (wt%) Mn (wt%) <![CDATA[H2O(wt%)]]> 76.42 0.0532 0.1123 0.0109 0.5203 25.23 Table 6 Manganese Removal Reaction Parameters Example ml of water Step 1: Sodium hydroxide tablets (g) Step 2: Potassium hydroxide g flocculant g Manganese AMVg Sodium persulfate g Slurry 6 500 47 2 35g aluminum sulfate and 5g aluminum hydroxide 100 7.78 Slurry 6 7 500 42 3 wet flocculation residue 100 7.78 Slurry 7 8 500 42 2 wet flocculation residue 100 7.78 Slurry 8 9 500 42 1 wet flocculation residue 100 7.78 Slurry 9 10 500 42 3 wet flocculation residue 100 7.78 10g of slurry The test data of the slurry in Examples 6-10 are shown in Table 7.

[0052] Table 7 Manganese removal rate and vanadium loss in the pulping process Pulping liquid batch number Number of cycles <![CDATA[V2O5(g / L)]]> Mn (g / L) before manganese removal Mn (g / L) in slurry Mn ratio <![CDATA[V2O5 loss rate]]> Slurry 6 0 98.60 0.7780 0.0016 99.79% 13.72% Slurry 7 1 115.12 0.7780 0.0014 99.82% -0.74% Slurry 8 2 112.36 0.7780 0.0009 99.88% 1.68% Slurry 9 3 120.26 0.7780 0.0006 99.92% -5.23% 10g of slurry 4 110.52 0.7780 0.0010 99.87% 3.29% As shown in Table 7, the mixture of aluminum sulfate and aluminum hydroxide and its flocculated residue had a good effect on manganese removal. The manganese content in the slurry was between 0.6 and 1.6 mg / L, and the manganese removal rate was between 99.79% and 99.92%. The initial manganese removal resulted in a relatively large V2O5 loss rate of 13.72%, while the maximum V2O5 loss rate after circulation was 3.29%. The difference between leaching and entrainment was not significant, and the V2O5 concentration basically reached a dynamic equilibrium. Only the first batch of flocculated residue carried a relatively large amount of vanadium. After backwashing, the total vanadium recovery rate of the raw material was 99.80%.

[0053] Table 8 High-purity AMV detection data Example <![CDATA[V2O5(wt%)]]> K (wt%) Na (wt%) Fe (wt%) Cr (wt%) Mn (wt%) Si (wt%) 6 77.75 0.0032 0.0052 0.0002 0.0002 0.0000 0.0083 7 77.73 0.0036 0.0042 0.0001 0.0003 0.0000 0.0075 8 77.71 0.0028 0.0043 0.0002 0.0002 0.0000 0.0068 9 77.73 0.0035 0.0036 0.0004 0.0003 0.0000 0.0057 10 77.69 0.0036 0.0041 0.0003 0.0004 0.0000 0.0078 As can be seen from Table 8, the high-purity AMV prepared after manganese removal has zero Mn content and other impurity contents of less than 100 ppm. The purity of AMV is greater than 99.90%, and it can be used for the production of high-purity vanadium and vanadium electrolyte.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing high-purity ammonium metavanadate through deep manganese removal, characterized in that, Includes the following steps: Step 1: Dissolve the alkali and flocculant in water, and heat the solution to 80℃~90℃; the amount of alkali added is 60~100g / L, and the amount of flocculant added is 30~80g / L; Step 2: Add manganese-vanadium raw material to the solution to make the Mn concentration in the solution 0.1~1.4g / L, and adjust the pH to 9~10 with alkali to dissolve the vanadium and manganese in the manganese-vanadium raw material in the solution; Step 3: Add an oxidant to the solution, the amount of which is 10 to 20 times the mass of Mn in the solution. Heat the solution to 80°C to 90°C and react for 2 to 3 hours. Filter to obtain slurry and flocculent residue. Add water to the flocculent residue to adjust the slurry and return it to Step 1 to replace the flocculant for recycling. Step 4: Dilute the slurry with water to a V₂O₅ concentration of 70-90 g / L. Add vanadium-containing waste electrolyte to adjust the solution color to pale yellow and adjust the pH to 7.0-8.

0. The H₂ in the vanadium-containing waste electrolyte... + The concentration is 1~10 mol / L, and the vanadium ion concentration is 0.2~2.5 mol / L; vanadium is precipitated by adding ammonium salt, and the amount of ammonium salt added is 1.5~2.0 times the mass of V2O5 in the solution, to obtain high-purity AMV solid; The flocculant mentioned in step 1 is one or more of zinc sulfate, zinc chloride, polyaluminum chloride, magnesium sulfate, aluminum sulfate, sodium aluminate, aluminum oxide, ferrous sulfate, and aluminum hydroxide.

2. The method for preparing high-purity ammonium metavanadate by deep manganese removal according to claim 1, characterized in that, The oxidant mentioned in step 3 is one or more of the following: air, oxygen, ozone, perchloric acid, sodium chlorate, potassium chlorate, potassium permanganate, ammonium persulfate, hydrogen peroxide, and sodium persulfate.

3. The method for preparing high-purity ammonium metavanadate by deep manganese removal according to claim 1, characterized in that, Step 4: Vanadium-containing waste electrolyte mainly contains H + VO2 + VO 2+ , or H + V 3+ VO 2+ .

4. The method for preparing high-purity ammonium metavanadate by deep manganese removal according to claim 1, characterized in that, The ammonium salt mentioned in step 4 is one or more of ammonium sulfate, ammonium chloride, ammonium bisulfate, ammonium nitrate, ammonium carbonate, and ammonium bicarbonate.

5. The method for preparing high-purity ammonium metavanadate by deep manganese removal according to claim 1, characterized in that, The alkali mentioned in steps 1 and 2 is one or more of sodium carbonate, potassium carbonate, potassium hydroxide, and sodium hydroxide.

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