Method for preparing high-purity vanadium pentoxide from carbonation leachate

Abstract

The invention provides a method for preparing high-purity vanadium pentoxide from carbonation leachate. The method comprises the following steps: S1) carrying out silicon removal on the carbonation leachate, and carrying out solid-liquid separation to obtain silicon-removed slag and silicon-removed liquid; s2) mixing the post-silicon-removal liquid with a complexing agent, and reacting to obtain a post-reaction liquid; s3) carrying out vanadium precipitation on the reacted liquid to obtain ammonium metavanadate and vanadium precipitation wastewater; s4) oxidizing and calcining the ammonium metavanadate to obtain high-purity vanadium pentoxide; the complexing agent is selected from one or more of ethylene diamine tetraacetic acid, disodium ethylene diamine tetraacetate and tetrasodium ethylene diamine tetraacetate. According to the method, the leaching solution obtained through the vanadium slag low-calcium roasting-carbonation leaching vanadium extraction technology serves as the raw material, ions such as iron, calcium and magnesium are controlled to enter the vanadium product through complexing, high-purity vanadium pentoxide with the low impurity content is obtained, the technological process is simple, implementation is easy, the cost is low, and the method is one of the methods for preparing high-purity vanadium pentoxide through the carbonation leaching solution.

Description

Technical Field

[0001] The invention relates to the technical field of vanadium extraction and metallurgy, and in particular to a method for preparing high-purity vanadium pentoxide by carbonating leaching solution. Background Art

[0002] Vanadium slag is the main raw material for the production of vanadium oxide. The traditional industrial process is sodium roasting-water leaching to extract vanadium. This process uses a large amount of sodium carbonate as a roasting additive and has high water treatment costs, which increases the production cost of vanadium oxide. During the treatment of vanadium precipitation wastewater, a large amount of difficult-to-treat solid waste such as vanadium chromium filter cake and sodium sulfate will be produced, which poses a great environmental risk.

[0003] In order to solve the problems of high production cost and great environmental risks of existing vanadium oxide, some researchers have proposed a process idea of ​​vanadium slag calcination roasting-carbonation leaching to extract vanadium: during the carbonation leaching process of vanadium-containing clinker, a small amount of impurities such as silicon, phosphorus, iron, and calcium dissolve into the leaching solution and exist stably, so that vanadium products that meet the application in the steel field can be prepared, but vanadium products with low iron content cannot be directly prepared, which affects the application of vanadium in non-steel fields.

[0004] In view of the problem of iron removal from carbonated leaching solution, Chinese patent No. CN116555591A provides a method for iron removal from carbonated vanadium leaching solution, which is achieved by adjusting the pH of the leaching solution to 10-12, and then adding soluble nickel salts such as nickel sulfate, nickel chloride, and nickel nitrate to remove iron at 90-100°C; Chinese patent No. CN116656949A provides a method for impurity removal from carbonated vanadium leaching solution, which is achieved by adjusting the pH of the leaching solution to 10.5-12.5, and adding soluble zinc salts such as zinc sulfate, zinc chloride, and zinc nitrate to remove iron at 90-100°C. In the above iron removal methods, the iron removal reagent introduces sulfate, chloride, and nitrate ions into the solution system, which cannot meet the technical requirements for recycling process water in the vanadium slag calcination roasting-carbonation leaching vanadium extraction process.

[0005] The technical problem of how to prepare high-purity vanadium pentoxide using carbonated leaching solution without affecting the recycling of process water so that it meets the application index requirements in the non-steel field needs to be solved. Summary of the invention

[0006] The technical problem solved by the present invention is to provide a method for preparing high-purity vanadium pentoxide by carbonated leaching solution. The method provided by the present application can obtain a high-purity vanadium product, and further retains the advantage that vanadium precipitation wastewater can be recycled to leach clinker.

[0007] In view of this, the present application provides a method for preparing high-purity vanadium pentoxide by carbonated leaching solution, comprising the following steps:

[0008] S1) desiliconizing the carbonated leaching solution, and performing solid-liquid separation to obtain desiliconized slag and desiliconized liquid;

[0009] S2) mixing the desiliconized liquid and a complexing agent, and reacting to obtain a reacted liquid;

[0010] S3) subjecting the reaction liquid to vanadium precipitation to obtain ammonium metavanadate and vanadium precipitation wastewater;

[0011] S4) oxidizing and calcining the ammonium metavanadate to obtain high-purity vanadium pentoxide;

[0012] The complexing agent is selected from one or more of ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetate and tetrasodium ethylenediaminetetraacetate.

[0013] Preferably, the carbonation leaching solution is obtained by leaching vanadium slag blank or calcified roasted clinker through one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate and ammonium bicarbonate.

[0014] Preferably, in step S1), the desiliconizing agent is selected from sodium aluminate, and the amount of sodium aluminate is added according to the molar ratio of Al / Si of (0.8-1.0):1; the desiliconizing temperature is 50-70°C, and the time is 0.5-2h.

[0015] Preferably, in step S2), the complexing agent is added in an amount according to a molar ratio of EDTA / Fe of (1.2-1.5):1, the reaction temperature is 50-70°C, and the reaction time is 1-5h.

[0016] Preferably, in step S3), before the vanadium precipitation, the process further comprises: cooling the reaction liquid to 15-30°C.

[0017] Preferably, in step S3), the reagent for vanadium precipitation is selected from one or more of ammonia water, ammonium carbonate and ammonium bicarbonate, and the amount of the reagent for vanadium precipitation is based on the amount of NH4 + The molar ratio of V / V is 2.6 to 3.5:1; the pH of the vanadium precipitation is 9.0 to 9.5.

[0018] Preferably, in step S4), the temperature of the oxidative calcination is 500-600° C. and the time is 3-5 hours.

[0019] Preferably, step S4) further includes:

[0020] The vanadium precipitation wastewater is supplemented with leaching reagents and then recycled for leaching clinker.

[0021] Preferably, the leaching agent is selected from one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate and ammonium bicarbonate.

[0022] The present application provides a method for preparing high-purity vanadium pentoxide from a carbonated leachate, which comprises firstly removing silicon from the carbonated leachate, and performing solid-liquid separation to obtain a desiliconized slag and a desiliconized liquid; then mixing the desiliconized liquid with a chelating agent, using EDTA in the chelating agent to form a stable soluble complex with ions such as iron, calcium, magnesium, and manganese in the desiliconized liquid, and controlling the iron, calcium, magnesium, and manganese in the desiliconized liquid in the solution to avoid entering the vanadium product during the vanadium precipitation process; then precipitating vanadium in the reaction solution to obtain ammonium metavanadate, and finally oxidizing and calcining the ammonium metavanadate to obtain high-purity vanadium pentoxide; therefore, the present application uses the above method to use a chelating agent to chelate and stably control cations such as iron, calcium, manganese, and magnesium in the carbonated leachate in the solution, obtains high-purity vanadium pentoxide through vanadium precipitation, and reduces the impurity removal step.

[0023] Furthermore, the present application supplements the vanadium precipitation wastewater with leaching reagents and then recycles it for leaching clinker, thereby retaining the advantage of directly recycling the vanadium precipitation wastewater for leaching clinker. DETAILED DESCRIPTION

[0024] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0025] In view of the problem that the purity of vanadium pentoxide prepared by carbonated leaching solution in the prior art does not meet the application requirements in the non-steel field, the present application provides a method for preparing high-purity vanadium pentoxide by carbonated leaching solution, which uses a complexing agent to complex cations such as iron, calcium, and manganese in the carbonated leaching solution and stably controls them in the solution to avoid entering the vanadium product during the vanadium precipitation process, and high-purity vanadium pentoxide can be obtained by vanadium precipitation; specifically, an embodiment of the present invention discloses a method for preparing high-purity vanadium pentoxide by carbonated leaching solution, comprising the following steps:

[0026] S1) desiliconizing the carbonated leaching solution, and performing solid-liquid separation to obtain desiliconized slag and desiliconized liquid;

[0027] S2) mixing the desiliconized liquid and a complexing agent, and reacting to obtain a reacted liquid;

[0028] S3) subjecting the reaction liquid to vanadium precipitation to obtain ammonium metavanadate and vanadium precipitation wastewater;

[0029] S4) oxidizing and calcining the ammonium metavanadate to obtain high-purity vanadium pentoxide;

[0030] The complexing agent is selected from one or more of ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetate and tetrasodium ethylenediaminetetraacetate.

[0031] In the method for preparing high-purity vanadium pentoxide from a carbonated leaching solution, the present application first removes silicon from the carbonated leaching solution, and obtains silicon-removed slag and silicon-removed liquid after solid-liquid separation; in this process, the carbonated leaching solution is obtained by leaching blank vanadium slag or calcified roasted clinker through one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate and ammonium bicarbonate, wherein the vanadium slag is obtained by oxidative blowing of vanadium-containing molten iron, that is, the vanadium slag is vanadium slag well known to those skilled in the art, and the present application does not impose any special restrictions on this; specifically, the carbonated leaching solution includes: V 32-45 g / L, Si 0.20-0.30 g / L, P 0.10-0.20 g / L, Fe 0.10-0.15 g / L, Ca 0.01-0.05 g / L, Mg≤0.01 g / L, Mn≤0.01 g / L, pH 8.5-9.5; more specifically, the carbonated leaching solution includes: V 34-41 g / L, Si 0.23-0.26 g / L, P 0.13-0.16 g / L, Fe 0.12-0.14 g / L, Ca 0.02-0.04 g / L, Mg≤0.01 g / L, Mn≤0.01 g / L, pH 8.3-9.3. The carbonated leaching solution is alkaline, and the main impurities include silicon, iron and phosphorus, and the concentrations of other impurity elements are relatively low; under alkaline conditions, phosphorus does not affect the quality of vanadium products in alkaline ammonium salt vanadium precipitation, does not need to be specially removed, and will not be enriched during the process water circulation process. The desiliconizing agent for desiliconization is selected from sodium aluminate, and the amount of sodium aluminate is added according to the molar ratio of Al / Si of (0.8-1.0):1; the temperature of desiliconization is 50-70°C, and the time is 0.5-2h; specifically, the temperature of desiliconization is 50-60°C, and the time is 1-1.5h; the reaction is carried out in a water bath.

[0032] The present application then mixes the desiliconized liquid and the complexing agent, and obtains the reaction liquid after the reaction; the complexing agent includes one or more of ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetate and tetrasodium ethylenediaminetetraacetate; the complexing agent uses EDTA to form a stable soluble complex with iron, calcium, magnesium, manganese and other ions, and controls the iron, calcium, magnesium and manganese in the desiliconized liquid in the solution, so as to avoid entering the vanadium product during the vanadium precipitation process and affecting the purity of the vanadium product. In the present application, the amount of the complexing agent is added according to the molar ratio of EDTA / Fe of (1.2-1.5):1, and specifically, the amount of the complexing agent is added according to the molar ratio of EDTA / Fe of (1.3-1.4):1; the excess complexing agent fully converts iron, calcium, magnesium and phosphorus into complexes, avoiding the problem of insufficient conversion due to insufficient amount of complexing agent, so as to reduce the proportion of impurity metals entering the vanadium product. The reaction temperature is 50-70°C and the reaction time is 1-5h; specifically, the reaction temperature is 55-65°C and the reaction time is 2-4h; the above reaction temperature and reaction time are to ensure the stability of iron, calcium, magnesium, manganese and other ion complexes while increasing the conversion ratio of the complex.

[0033] According to the present invention, the reaction liquid is then subjected to vanadium precipitation to obtain ammonium metavanadate and vanadium precipitation wastewater; in the above process, the vanadium precipitation also includes: cooling the reaction liquid to 15-30°C, specifically, cooling to 20-25°C. The vanadium precipitation reagent is selected from one or more of ammonia water, ammonium carbonate and ammonium bicarbonate, and the amount of the vanadium precipitation reagent is based on the NH4 + / V is added at a molar ratio of 2.6 to 3.5:1; the pH of the vanadium precipitation is 9.0 to 9.5; specifically, the amount of the vanadium precipitation reagent is based on the NH4 + The molar ratio of V / V is 2.8 to 3.2:1; the pH of the vanadium precipitation is 9.2 to 9.4.

[0034] Finally, the ammonium metavanadate is subjected to oxidation calcination to obtain high-purity vanadium pentoxide; the oxidation calcination temperature is 500-600° C. and the time is 3-5 hours.

[0035] Furthermore, the present application also recycles the above-mentioned vanadium precipitation wastewater after supplementing the leaching reagent to be used for leaching clinker; the leaching reagent is selected from one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate and ammonium bicarbonate.

[0036] In order to further understand the present invention, the method for preparing high-purity vanadium pentoxide from carbonated leaching solution provided by the present invention is described in detail below in conjunction with examples, and the protection scope of the present invention is not limited by the following examples.

[0037] Example 1

[0038] Take 500mL of carbonated leaching solution (V 34.28g / L, Si 0.24g / L, P 0.13g / L, Fe0.12g / L, Ca0.02g / L, Mg 0.01g / L, Mn 0.01g / L and pH 8.87), heated to 70°C in a water bath, 0.31g of sodium aluminate was added and stirred for reaction for 1h. After the desiliconization reaction was completed, the solid-liquid separation was carried out to obtain desiliconization slag and desiliconization liquid (Si<0.01g / L); 0.5g of disodium ethylenediaminetetraacetate was added to the desiliconization liquid, the water bath was kept constant at 60°C and stirred for reaction for 4h. After the complexation reaction was completed, the solution was cooled to 25°C, 56g of ammonium carbonate was added and stirred for reaction for 3h. After the vanadium precipitation reaction was completed, the solid-liquid separation was carried out to obtain ammonium metavanadate and vanadium precipitation wastewater (V4.39g / L); ammonium metavanadate was calcined at a constant temperature of 550°C in a muffle furnace for 4h to obtain 26.57g of powdered vanadium pentoxide, the main chemical components of which were V2O5 99.82%, Si 0.012%, Fe 0.012%, Na 0.028%, K 0.021%, P<0.01%, Ca<0.01%, Mg<0.01% and Mn<0.01%.

[0039] Comparative Example 1 (without addition of complexing agent disodium ethylenediaminetetraacetate)

[0040] Take 500mL of carbonated leaching solution (V 34.28g / L, Si 0.24g / L, P 0.13g / L, Fe0.12g / L, Ca0.02g / L, Mg 0.01g / L, Mn 0.01g / L and pH 8.87), heat it to 70℃ in a water bath, add 0.31g of sodium aluminate and stir to react for 1h, after the desiliconization reaction is completed, separate the solid and liquid to obtain desiliconized slag and desiliconized liquid (Si<0.01g / L); cool the desiliconized liquid to 25℃, add 56g of ammonium carbonate and stir to react for 3h, after the vanadium precipitation reaction is completed, separate the solid and liquid to obtain ammonium metavanadate and vanadium precipitation wastewater (V 4.33g / L); calcine the ammonium metavanadate at 550℃ for 4h in a muffle furnace to obtain 26.65g of powdered vanadium pentoxide, the main chemical component of which is V2O5 99.71%, Si0.014%, Fe 0.086%, Na 0.026%, K0.020%, P<0.01%, Ca0.02%, Mg<0.01% and Mn<0.01%. The Fe and Ca contents in vanadium pentoxide products increase.

[0041] Example 2

[0042] Take 500mL of carbonated leaching solution (V 40.36g / L, Si 0.26g / L, P 0.15g / L, Fe0.14g / L, Ca0.02g / L, Mg<0.01g / L, Mn<0.01g / L and pH 9.28), heat it to 60°C in a water bath, add 0.34g of sodium aluminate and stir to react for 2h, after the desiliconization reaction is completed, separate the solid and liquid to obtain desiliconized slag and desiliconized liquid (Si<0.01g / L); add 0.71g of tetrasodium ethylenediaminetetraacetate to the desiliconized liquid, keep the water bath temperature at 50°C and stir to react for 5h, after the complexation reaction is completed, cool the solution to 20°C, add 30g of ammonium carbonate and 50g of ammonium bicarbonate and stir to react for 3h; after the vanadium precipitation reaction is completed, separate the solid and liquid to obtain ammonium metavanadate and vanadium precipitation wastewater (V 4.74g / L); ammonium metavanadate was calcined at 500°C for 5h in a muffle furnace to obtain 31.68g of powdered vanadium pentoxide, with main chemical components of V2O5 99.84%, Si 0.013%, Fe 0.012%, Na 0.030%, K0.022%, P<0.01%, Ca<0.01%, Mg<0.01%, and Mn<0.01%.

[0043] Comparative Example 2 (without adding complexing agent tetrasodium ethylenediaminetetraacetate)

[0044] Take 500mL of carbonated leaching solution (V 40.36g / L, Si 0.26g / L, P 0.15g / L, Fe0.14g / L, Ca0.02g / L, Mg<0.01g / L, Mn<0.01g / L and pH 9.28), heat it to 60℃ in a water bath, add 0.34g of sodium aluminate and stir to react for 2h, after the desiliconization reaction, separate the solid and liquid to obtain desiliconized slag and desiliconized liquid (Si<0.01g / L); cool the desiliconized liquid to 20℃, add 30g of ammonium carbonate and 50g of ammonium bicarbonate and stir to react for 3h, after the vanadium precipitation reaction, separate the solid and liquid to obtain ammonium metavanadate and vanadium precipitation wastewater (V 4.68g / L); calcine the ammonium metavanadate at 500℃ for 5h in a muffle furnace to obtain 31.76g of powdered vanadium pentoxide, the main chemical component of which is V2O5 99.68%, Si 0.014%, Fe 0.097%, Na 0.032%, K0.023%, P<0.01%, Ca 0.02%, Mg<0.01%, Mn<0.01%. The Fe and Ca contents in vanadium pentoxide products increase.

[0045] Example 3

[0046] Take 500mL of carbonated leaching solution (V 38.84g / L, Si 0.23g / L, P 0.16g / L, Fe0.12g / L, Ca0.02g / L, Mg<0.01g / L, Mn<0.01g / L and pH 9.22), heated to 50°C in a water bath, added 0.28g of sodium aluminate and stirred for reaction for 1.5h, after the desiliconization reaction was completed, the solid-liquid separation was carried out to obtain desiliconization slag and desiliconization liquid (Si<0.01g / L); 0.41g of ethylenediaminetetraacetic acid was added to the desiliconization liquid, the water bath was kept constant at 70°C and stirred for reaction for 3h, after the complexation reaction was completed, the solution was cooled to 15°C, 45g of ammonium bicarbonate and 37mL of 28% ammonia water were added, stirred for reaction for 3h, after the vanadium precipitation reaction was completed, the solid-liquid separation was carried out to obtain ammonium metavanadate and vanadium precipitation wastewater (V3.87g / L); ammonium metavanadate was calcined at a constant temperature of 550°C for 4h in a muffle furnace to obtain 30.85g of powdered vanadium pentoxide, the main chemical components of which were V2O5 99.85%, Si 0.012%, Fe 0.014%, Na 0.024%, K0.020%, P<0.01%, Ca<0.01%, Mg<0.01% and Mn<0.01%.

[0047] Comparative Example 3 (without adding complexing agent EDTA)

[0048] Take 500mL of carbonated leaching solution (V 38.84g / L, Si 0.23g / L, P 0.16g / L, Fe0.12g / L, Ca0.02g / L, Mg<0.01g / L, Mn<0.01g / L and pH 9.22), heat it in a water bath to 50°C, add 0.28g of sodium aluminate and stir to react for 1.5h, after the desiliconization reaction is completed, separate the solid and liquid to obtain desiliconized slag and desiliconized liquid (Si<0.01g / L); cool the desiliconized liquid to 15°C, add 45g of ammonium bicarbonate and 37mL of 28% ammonia water, stir to react for 3h, after the vanadium precipitation reaction is completed, separate the solid and liquid to obtain ammonium metavanadate and vanadium precipitation wastewater (V 3.91g / L); ammonium metavanadate was calcined at 550℃ for 4h in a muffle furnace to obtain 30.86g of powdered vanadium pentoxide, with the main chemical components of V2O5 99.69%, Si 0.013%, Fe 0.095%, Na0.026%, K0.021%, P<0.01%, Ca 0.02%, Mg<0.01% and Mn<0.01%. The Fe and Ca contents in the vanadium pentoxide product increased.

[0049] In summary, the method for preparing high-purity vanadium pentoxide from carbonated leaching solution of the present invention, in the process of vanadium precipitation, by adding a complexing agent, cations such as iron, calcium, magnesium, manganese and the like in the solution are complexed and stably controlled in the solution, so that the iron and calcium contents in the vanadium pentoxide product are significantly reduced, creating conditions for the application of vanadium products in non-steel fields.

[0050] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0051] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing high-purity vanadium pentoxide by carbonating a leaching solution, comprising the following steps: S1) desiliconizing the carbonated leaching solution, and performing solid-liquid separation to obtain desiliconized slag and desiliconized liquid; S2) mixing the desiliconized liquid and a complexing agent, and reacting to obtain a reacted liquid; S3) subjecting the reaction liquid to vanadium precipitation to obtain ammonium metavanadate and vanadium precipitation wastewater; S4) oxidizing and calcining the ammonium metavanadate to obtain high-purity vanadium pentoxide; The complexing agent is selected from one or more of ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetate and tetrasodium ethylenediaminetetraacetate.

2. The method according to claim 1, characterized in that The carbonation leaching solution is obtained by leaching vanadium slag blank or calcified roasted clinker through one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate and ammonium bicarbonate.

3. The method according to claim 1, characterized in that In step S1), the desiliconizing agent is selected from sodium aluminate, and the amount of sodium aluminate is added according to the molar ratio of Al / Si of (0.8-1.0):1; the desiliconizing temperature is 50-70°C, and the time is 0.5-2h.

4. The method according to claim 1, characterized in that: In step S2), the complexing agent is added at a molar ratio of EDTA / Fe of (1.2-1.5):1, the reaction temperature is 50-70°C, and the reaction time is 1-5h.

5. The method according to claim 1, characterized in that In step S3), before the vanadium precipitation, the method further comprises: cooling the reaction liquid to 15-30°C.

6. The method according to claim 1, characterized in that In step S3), the reagent for vanadium precipitation is selected from one or more of ammonia water, ammonium carbonate and ammonium bicarbonate, and the amount of the reagent for vanadium precipitation is based on the amount of NH4 + The molar ratio of V / V is 2.6 to 3.5:1; the pH of the vanadium precipitation is 9.0 to 9.

5.

7. The method according to claim 1, characterized in that In step S4), the temperature of the oxidation calcination is 500-600° C. and the time is 3-5 hours.

8. The method according to any one of claims 1 to 7, characterized in that: Step S4) also includes: The vanadium precipitation wastewater is supplemented with leaching reagent and then recycled for leaching clinker.

9. The method according to claim 8, characterized in that The leaching agent is selected from one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate and ammonium bicarbonate.