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, adding aluminum salt into the carbonation leachate to remove silicon, and carrying out solid-liquid separation to obtain silicon-removed liquid; s2, mixing the silicon-removed liquid with ammonium salt, and performing solid-liquid separation after vanadium precipitation to obtain crude ammonium metavanadate; s3, re-dissolving the coarse ammonium metavanadate, carrying out stirring reaction on the obtained coarse ammonium metavanadate re-dissolved slurry, and carrying out solid-liquid separation to obtain an ammonium metavanadate solution; s4, a complexing agent and ammonium salt are added into the ammonium metavanadate solution for vanadium precipitation, and high-purity ammonium metavanadate is obtained after solid-liquid separation; and S5, carrying out high-temperature calcination on the high-purity ammonium metavanadate to obtain the high-purity vanadium pentoxide. According to the method provided by the invention, the high-purity vanadium pentoxide with low impurity content is obtained by adopting the technological means of deeply removing silicon, re-dissolving to remove iron and separating cations such as calcium, potassium, sodium and the like into the vanadium product through complexing crystallization, and the method is simple in technological process, low in auxiliary material consumption and relatively low in cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of extraction metallurgy of vanadium, and particularly relates to a method for preparing high-purity vanadium pentoxide from carbonated leaching solution. BACKGROUND

[0002] Vanadium slag is the main raw material for producing vanadium oxide. The traditional industrial process is sodium calcination-vanadium leaching. The process has a large amount of sodium carbonate additive for calcination and high water treatment cost, resulting in high production cost of vanadium oxide. The treatment of vanadium precipitation wastewater produces a large amount of vanadium chromium filter cake and sodium sulfate, which are difficult to handle, and the environmental protection risk is large. In order to solve the problems of high production cost and large environmental protection risk of existing vanadium oxide, a process flow of vanadium slag calcination-vanadium leaching by carbonation is proposed, which can realize direct recycling of vanadium precipitation wastewater, avoid the generation of sodium sulfate solid waste from water treatment, greatly reduce the process cost, and the specific process is described in the Chinese patent with the publication number CN110106344A. In the carbonation leaching process of vanadium-containing clinker, a small amount of impurities such as silicon, potassium, iron and calcium are dissolved into the leaching solution and stably exist, which can prepare vanadium products meeting the application in the steel field, but cannot directly prepare vanadium products meeting the quality standards of non-steel field applications such as denitration catalyst and vanadium electrolyte, which affects the application of vanadium products in the non-steel field.

[0003] In view of the high iron concentration of the carbonated leaching solution, the Chinese patent with publication number CN116555591A provides a method for removing iron from carbonated vanadium leaching solution. The pH of the leaching solution is adjusted to 10-12, and then soluble nickel salts such as nickel sulfate, nickel chloride, and nickel nitrate are added to remove iron at 90-100°C. The Chinese patent with publication number CN116656949A provides a method for removing impurities from carbonated vanadium leaching solution. The pH of the leaching solution is adjusted to 10.5-12.5, and then soluble zinc salts such as zinc sulfate, zinc chloride, and zinc nitrate are added to remove iron at 90-100°C. However, the above-mentioned iron removal reagents introduce sulfate ions, chloride ions, and nitrate ions into the solution system, which cannot meet the technical requirements of process water recycling in the vanadium slag calcification roasting-carbonation leaching process. The Chinese patent with publication number CN119660796A provides a method for removing silicon from carbonated leaching solution, complexing iron ions, and precipitating ammonium metavanadate to prepare high-purity vanadium oxide. The obtained vanadium pentoxide contains 0.012%-0.014% Fe, 0.020%-0.022% K, and 0.024%-0.030% Na. The vanadium pentoxide prepared by this method has relatively high contents of iron, potassium, and sodium, which cannot meet the technical requirements of some application fields. The Chinese patent with publication number CN119637936A provides a method for preparing vanadium pentoxide from ammonium metavanadate containing iron. The ammonium metavanadate is slurried with water, and an iron ion complexing agent is added. The pH is adjusted to 1.8-2.2 using sulfuric acid to precipitate ammonium polyvanadate, and vanadium pentoxide is obtained by calcination. However, this method introduces sulfate ions, which cannot meet the technical requirements of process water recycling in the vanadium slag calcification roasting-carbonation leaching process.

[0004] Therefore, how to use the carbonated leaching solution to prepare high-purity vanadium pentoxide without affecting the process water recycling of the vanadium slag blank or calcification roasting-carbonation leaching main process, and to meet the technical requirements of the application index in the non-steel field needs further optimization and improvement. SUMMARY

[0005] The technical problem solved by the present application is to provide a method for preparing high-purity vanadium pentoxide from carbonated leaching solution. The method provided by the present application can achieve deep separation of vanadium and impurity elements in the carbonated leaching solution, and ultimately prepare high-purity vanadium pentoxide.

[0006] Therefore, the present application provides a method for preparing high-purity vanadium pentoxide from carbonated leaching solution, which comprises the following steps:

[0007] S1, adding an aluminum salt to the carbonated leaching solution to remove silicon, and performing solid-liquid separation to obtain a silicon-removed residue and a silicon-removed solution;

[0008] S2, mixing the silicon-removed solution with an ammonium salt, performing solid-liquid separation after vanadium precipitation, and obtaining crude ammonium metavanadate and a primary vanadium precipitation mother liquor;

[0009] S3, the crude ammonium metavanadate is resolubilized, the obtained crude ammonium metavanadate resolubilization slurry is subjected to stirring reaction, and after solid-liquid separation, iron removal residue and ammonium metavanadate solution are obtained;

[0010] S4, a complexing agent is added to the ammonium metavanadate solution, vanadium is precipitated with an ammonium salt, and after solid-liquid separation, high-purity ammonium metavanadate and secondary vanadium precipitation mother liquor are obtained;

[0011] S5, the high-purity ammonium metavanadate is subjected to high-temperature calcination to obtain high-purity vanadium pentoxide.

[0012] In some specific embodiments, in step S1, the aluminum salt comprises sodium aluminate, and the sodium aluminate is added in a molar ratio of Al:Si of (1.05-1.2):1; and / or, the silicon removal temperature is 30-100°C, and the silicon removal time is 30-60 min.

[0013] In some specific embodiments, in step S2, the ammonium salt comprises one or more of ammonium carbonate, ammonium bicarbonate and ammonia water, and / or the ammonium salt is added in a molar ratio of NH4 + :V in the vanadium precipitation solution of 2.5-3.5:1, and / or the vanadium precipitation temperature is 15-30°C, and the vanadium precipitation time is 100-300 min.

[0014] In some specific embodiments, in step S3, the resolubilization is specifically:

[0015] After the crude ammonium metavanadate and water are mixed and beaten, heating is performed, and the heating temperature is 80-100°C.

[0016] In some specific embodiments, the solid-liquid ratio of the crude ammonium metavanadate and the water is 1g:(19-25)mL.

[0017] In some specific embodiments, in step S3, the stirring reaction is specifically: the crude ammonium metavanadate resolubilization slurry is stirred at 90-100°C for 60-180 min; or, a coprecipitation agent is added to the crude ammonium metavanadate resolubilization slurry, and stirring is performed at 80-100°C for 10-60 min, the coprecipitation agent comprises sodium aluminate, and the coprecipitation agent is added in an amount of 0.1-0.6g / L of the crude ammonium metavanadate resolubilization slurry.

[0018] In some specific embodiments, in step S3, before the addition of the coprecipitation agent, the following step is further included:

[0019] The crude ammonium metavanadate resolubilization slurry is separated from the iron residue.

[0020] In some embodiments, in step S4, the amount of the complexing agent added is controlled according to a concentration of 0.5-1 g / L of the complexing agent in the ammonium metavanadate solution; and / or, before the vanadium precipitation of the ammonium salt, the ammonium metavanadate solution is cooled to 20-35℃; and / or, the complexing agent comprises EDTA, and the ammonium salt comprises one or both of ammonium carbonate and ammonium bicarbonate; and / or, the amount of the ammonium salt added is controlled according to a concentration of 3-6 g / L of NH4 + .

[0021] In some embodiments, in step S5, the high-temperature calcination is performed at a temperature of 500-800℃ for 5-10 h.

[0022] In some embodiments, the carbonated leaching solution is obtained by leaching vanadium slag blank or calcified clinker with one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate, and ammonium bicarbonate, and the carbonated leaching solution has V≥15 g / L, Na≥30 g / L, CO3 2- ≥40 g / L, Si≥0.15 g / L, K≥0.2 g / L, Fe≥0.05 g / L, Ca≥0.01 g / L, and Cr≤0.02 g / L.

[0023] The present application provides a method for preparing high-purity vanadium pentoxide from a carbonated leaching solution. First, aluminum salt is added to the carbonated leaching solution to deeply remove silicon, and then the solution after the silicon removal is precipitated to obtain crude ammonium metavanadate, so that vanadium is fully separated from silicon, and also from most of iron, potassium, sodium, and phosphorus. Then, the crude ammonium metavanadate is re-dissolved and stirred to react, so that the iron hydroxide gel generated by the re-dissolution is coagulated or co-precipitated, achieving the purpose of deeply separating iron. Meanwhile, after the re-dissolution of the crude ammonium metavanadate, potassium, sodium, calcium, and other cations are dissolved into the solution at a low concentration, and a complexing agent is added to the precipitated ammonium metavanadate solution, so that calcium ions remain in the solution in the form of soluble ions, achieving the purpose of deeply separating vanadium from calcium, potassium, sodium, and other cations, and finally ensuring that high-purity vanadium pentoxide is obtained. DETAILED DESCRIPTION

[0024] In order to further understand the present application, the preferred embodiments of the present application are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present application, and are not limitations on the claims of the present application.

[0025] In view of the high iron concentration in the carbonated leaching solution in the prior art and the demand for preparing high-purity vanadium pentoxide, the application provides a method for preparing vanadium pentoxide from a carbonated leaching solution, which realizes deep separation of vanadium and impurity elements in the carbonated leaching solution by using a short process and a low-cost method without affecting the water recycling of a vanadium slag blank or a calcified roasting-carbonated leaching main process flow, and obtains high-purity vanadium pentoxide product. Specifically, the application discloses a method for preparing high-purity vanadium pentoxide from a carbonated leaching solution, which comprises the following steps:

[0026] S1, adding an aluminum salt to the carbonated leaching solution to remove silicon, and performing solid-liquid separation to obtain a silicon-removed residue and a silicon-removed solution;

[0027] S2, mixing the silicon-removed solution and an ammonium salt, performing vanadium precipitation, and performing solid-liquid separation to obtain crude ammonium metavanadate and a primary vanadium precipitation mother liquor;

[0028] S3, performing resolubilization of the crude ammonium metavanadate, stirring the obtained crude ammonium metavanadate resolubilization slurry, and performing solid-liquid separation to obtain an iron-removed residue and an ammonium metavanadate solution;

[0029] S4, adding a complexing agent and an ammonium salt to the ammonium metavanadate solution to precipitate vanadium, and performing solid-liquid separation to obtain high-purity ammonium metavanadate and a secondary vanadium precipitation mother liquor;

[0030] S5, performing high-temperature calcination of the high-purity ammonium metavanadate to obtain high-purity vanadium pentoxide.

[0031] In the process of preparing high-purity vanadium pentoxide from a carbonated leaching solution, in step S1, an aluminum salt is first added to the carbonated leaching solution to remove silicon, and solid-liquid separation is performed to obtain a silicon-removed residue and a silicon-removed solution. In the application, the carbonated leaching solution is obtained by leaching a vanadium slag blank or calcified roasting clinker with one or more of sodium carbonate, sodium bicarbonate, ammonium carbonate and ammonium bicarbonate. The vanadium slag contains vanadium, iron, silicon, potassium and calcium, and the leaching agent contains sodium and carbonate. The concentrations of the components are as follows: V≥15 g / L, Na≥30 g / L, CO3 2-≥40g / L, Si≥0.15g / L, K≥0.2g / L, Fe≥0.05g / L, Ca≥0.01g / L, Cr≤0.02g / L, etc., and other impurity element concentrations are relatively low. The aluminum salt includes sodium metaaluminate, and the sodium metaaluminate is added in an amount of (1.05-1.2):1 in terms of Al / Si molar ratio; the temperature for desilication is 30-70°C, and the desilication time is 30-60 min; specifically, the sodium metaaluminate is added in an amount of (1.10-1.15):1 in terms of Al / Si molar ratio; the temperature for desilication is 40-60°C, and the desilication time is 40-50 min; and deep desilication is achieved by adding an excess amount of aluminum salt. In the preparation of high-purity vanadium oxide, impurity elements need to be fully separated, and the above-mentioned aluminum salt desilication fully separates vanadium from silicon, and phosphorus does not affect the vanadium product quality of vanadium precipitation by an alkaline ammonium salt, and does not need to be specially removed, and will not be enriched in the process water circulation process.

[0032] In the process of one-time vanadium precipitation in step S2, the desilication liquid obtained by the above-mentioned solid-liquid separation and an ammonium salt are mixed, and solid-liquid separation is performed after vanadium precipitation to obtain crude meta-vanadate and a one-time vanadium precipitation mother liquor; in this process, the ammonium salt includes one or more of ammonium carbonate, ammonium bicarbonate, and ammonia water; specifically, the ammonium salt is selected from one or two of ammonium carbonate, ammonium bicarbonate, and ammonia water, and the selection of the ammonium salt is considered from the perspective of not affecting the process water recycling in the main process. In the above-mentioned vanadium precipitation process, vanadium is separated from most of the impurities such as potassium, sodium, and phosphorus, and part of iron, calcium, and aluminum will enter the crude meta-vanadate. The ammonium salt is added in an amount of 2.6-3.5:1 in terms of NH4 + / V molar ratio, specifically, 2.8-3.3:1 in terms of NH4 + / V molar ratio, more specifically, 2.9-3.0:1 in terms of NH4 + / V molar ratio. The vanadium precipitation temperature is 15-30°C, and the vanadium precipitation time is 100-300 min; specifically, the vanadium precipitation temperature is 16-27°C, and the vanadium precipitation time is 180-270 min; more specifically, the vanadium precipitation temperature is 18-20°C, and the vanadium precipitation time is 210-240 min.

[0033] According to the present application, in step S3, the crude ammonium metavanadate is reslurried, and the obtained reslurried crude ammonium metavanadate is stirred to obtain an iron removal residue and an ammonium metavanadate solution. In this process, the reslurrying is specifically slurring the crude ammonium metavanadate with pure water and heating; the slurring of the crude ammonium metavanadate with pure water at a temperature of 80-100°C and a solid-liquid ratio of 1:19-22 (g:mL) is to increase the solubility of the crude ammonium metavanadate and speed up the dissolution of the crude ammonium metavanadate, so that the crude ammonium metavanadate is fully dissolved; specifically, the temperature is 90-96°C, and the solid-liquid ratio is 1:20-21. The pH of the reslurried crude ammonium metavanadate is 7-8, in which part of the iron is precipitated as iron hydroxide, and part of the iron exists in the solution in the form of iron hydroxide colloid. Then the obtained reslurried crude ammonium metavanadate is stirred, in which the reslurried ammonium metavanadate is not added with any reagent, and is stirred at 90-100°C for 60-180 min to speed up the movement of the iron hydroxide colloid particles and increase the chance of collision between the particles, so that the particles are aggregated and precipitated, achieving the purpose of iron removal; alternatively, a co-precipitation agent sodium aluminate is added, and is stirred at 80-100°C for 20-60 min, because under the condition of pH=7-8, the sodium aluminate is hydrolyzed into aluminum hydroxide, which adsorbs the iron hydroxide colloid and neutralizes the charge of the colloid, so that the iron hydroxide colloid and the aluminum hydroxide are co-precipitated, achieving the purpose of iron removal. Compared with the method of separating iron by co-precipitation with calcium oxide, the separation of iron by co-precipitation without adding any reagent or by adding sodium aluminate co-precipitation agent, the added aluminum ions are fully hydrolyzed and precipitated, avoiding the increase of impurity concentration in the iron removal process, and at the same time, the vanadium loss is greatly reduced. The amount of the co-precipitation agent sodium aluminate is controlled at 0.1-0.6 g / L, and specifically, the amount of the co-precipitation agent sodium aluminate is controlled at 0.4-0.5 g / L. In the above process, the reslurried crude ammonium metavanadate can be first separated into an iron removal residue, and then the co-precipitation agent sodium aluminate is added, and the aluminum residue generated in this way can be returned to step S1 for recycling for silicon removal.

[0034] In the secondary vanadium precipitation process of step S4, the above ammonium metavanadate solution is added with a complexing agent, and ammonium salt is used for vanadium precipitation. After solid-liquid separation, high-purity ammonium metavanadate and secondary vanadium precipitation mother liquor are obtained. In this process, the concentration of calcium, potassium, sodium and other cations in the ammonium metavanadate solution after iron separation is low. The addition of the complexing agent complexes with calcium and other cations, so that they exist in the solution in the form of stable soluble ions, avoiding precipitation into ammonium metavanadate during vanadium precipitation. The complexing agent is selected from EDTA, and the addition amount of the complexing agent is 0.5-1 g / L based on the concentration of the complexing agent in the ammonium metavanadate solution. Specifically, the concentration of the complexing agent is 0.7-0.8 g / L. The solution after adding the complexing agent is preferably cooled to 20-35°C before the ammonium salt is added for vanadium precipitation. This is because the potassium and sodium concentrations in the ammonium metavanadate solution are low, and the proportion of potassium and sodium entering the ammonium metavanadate is low during cooling and recrystallization. The potassium and sodium contents in the corresponding ammonium metavanadate are low, thereby achieving the purpose of deeply removing calcium, potassium, sodium and other cations. The addition amount of the ammonium salt is controlled according to the NH4 + concentration of 3-6 g / L in the solution. Specifically, the addition amount of the ammonium salt is controlled according to the NH4 + concentration of 4-5 g / L in the solution. The ammonium salt includes one or both of ammonium carbonate and ammonium bicarbonate.

[0035] The application finally calcines the above high-purity ammonium metavanadate at high temperature to obtain high-purity vanadium pentoxide. The high-temperature calcination temperature is 500-800°C, and the time is 5-10h. Specifically, the high-temperature calcination temperature is 550-700°C, and the time is 6-8h.

[0036] In the application, part of the secondary vanadium precipitation mother liquor in step S4 is returned to step S2 for washing the crude ammonium metavanadate, and the remaining part is returned to the clinker leaching process for washing the leaching residue.

[0037] In the method for preparing high-purity vanadium pentoxide by carbonation leaching solution provided by the application, the crude ammonium metavanadate is pulped and heated for resolubilization. Compared with the existing technology of resolubilization process using sodium hydroxide alkali solution and ammonium bicarbonate, ammonium carbonate and ammonia water, the reagent consumption is reduced, and the resolubilization cost is lowered. At the same time, the problem of high sodium content in high-purity vanadium pentoxide caused by the introduction of sodium due to alkali dissolution is avoided. The ammonium metavanadate resolubilization solution is stirred at high temperature and constant temperature without adding reagents, or adding a coprecipitant sodium aluminite, so that the iron hydroxide colloid generated by resolubilization is flocculated or co-precipitated. Compared with the existing method of removing iron by adding calcium oxide, the vanadium loss is reduced. The introduction of impurity ions calcium is avoided, and the calcium removal process is omitted. Further, the ammonium metavanadate resolubilization solution is added with a complexing agent and cooled for vanadium precipitation, which reduces the potassium, sodium and calcium cation content in high-purity vanadium pentoxide, and solves the influence of cations on vanadium product quality at low cost.

[0038] For a further understanding of the present application, the method for preparing high-purity vanadium oxide from carbonated leach liquor provided by the present application is described in detail below in conjunction with examples, and the protection scope of the present application is not limited by the following examples.

[0039] The reagents in the following examples are all known products, which are obtained commercially.

[0040] Example 1

[0041] Take 800 mL of carbonated leach liquor (V 41.94 g / L, Na 41.80 g / L, Si 0.25 g / L, K 0.34 g / L, P 0.11 g / L, Fe 0.16 g / L, Ca 0.02 g / L, Cr 0.001 g / L, Al 0.001 g / L, CO3 2- 87.64 g / L and pH 9.52), heat to 70℃ in a water bath, and add 0.70 g of sodium aluminate according to the Al / Si molar ratio of 1.2 and stir for 30 min; after the silicon removal reaction is completed, solid-liquid separation is performed to obtain silicon removal residue and silicon removal solution;

[0042] According to the NH4 + / V molar ratio of 3.0, add 46.9 g of ammonium carbonate and 77.2 g of ammonium bicarbonate to the silicon removal solution, and stir for 240 min at a water bath temperature of 15℃ to perform the first vanadium precipitation; after the vanadium precipitation reaction is completed, solid-liquid separation is performed to obtain crude ammonium metavanadate and a first vanadium precipitation mother liquor; the crude ammonium metavanadate is slurried with 1600 mL of pure water, heated to 96℃ in a water bath, and stirred for 180 min at constant temperature to perform the reaction, and then solid-liquid separation and washing of the iron removal residue are performed to obtain an ammonium metavanadate solution;

[0043] According to the complexing agent concentration of 1 g / L, add 1.6 g of EDTA to the ammonium metavanadate solution, reduce the water bath temperature to 15℃, then add 24 g of ammonium carbonate, and continue to stir for 180 min to perform the reaction; after the vanadium precipitation reaction is completed, solid-liquid separation is performed to obtain high-purity ammonium metavanadate and a second vanadium precipitation mother liquor; the high-purity ammonium metavanadate is oxidized and calcined in a muffle furnace at 550℃ for 240 min to obtain high-purity vanadium oxide.

[0044] Table 1 Data table of changes in main components of carbonated leach liquor and vanadium products in Example 1

[0045] Material name V Na Cr Si P Fe K Ca Al Carbonated leach solution (g / L) 41.94 41.80 0.001 0.25 0.11 0.16 0.34 0.02 0.001 Post-silica removal solution (g / L) 41.73 41.46 0.001 0.002 0.08 0.15 0.32 0.02 0.042 Crude ammonium metavanadate (wt%) 43.25 0.023 0.001 0.002 0.003 0.089 0.021 0.012 0.028 Ammonium metavanadate solution (g / L) 19.28 0.011 <0.001 0.001 0.001 0.005 0.010 0.006 0.002 High purity vanadium oxide (wt%) 55.93 0.003 0.001 0.002 0.001 0.007 0.003 0.002 0.002

[0046] Example 2

[0047] Take 800 mL of carbonated leach liquor (V 41.94 g / L, Na 41.80 g / L, Si 0.25 g / L, K 0.34 g / L, P 0.11 g / L, Fe 0.16 g / L, Ca 0.02 g / L, Cr 0.001 g / L, Al 0.001 g / L, CO32- 87.64 g / L and pH 9.52), heated in a water bath to 60°C, added 0.64 g of sodium aluminate according to an Al / Si molar ratio of 1.10, and stirred for 60 minutes; after the desiliconization reaction, solid-liquid separation was completed to obtain desiliconized slag and desiliconized liquid;

[0048] According to the NH4 + At a molar ratio of 3.0, 93.8 g of ammonium carbonate was added to the desiliconized liquid, and the mixture was stirred at a water bath temperature of 18° C. for 210 min to perform a primary vanadium precipitation. After the vanadium precipitation reaction, the solid-liquid separation was performed to obtain crude ammonium metavanadate and a primary vanadium precipitation mother liquor. The crude ammonium metavanadate was slurried with 1550 mL of pure water, heated to 90° C. in a water bath, and stirred at a constant temperature for 30 min. Then, 0.62 g of sodium metaaluminate was added to the crude ammonium metavanadate re-dissolved slurry at a coprecipitant dosage of 0.4 g / L, and the stirring was continued for 20 min. The solid-liquid separation was performed and the iron removal slag was washed to obtain an ammonium metavanadate solution.

[0049] Based on a complexing agent concentration of 0.8 g / L, 1.24 g of EDTA was added to the ammonium metavanadate solution, the temperature was cooled to 18°C ​​in a water bath, and then 24 g of ammonium carbonate was added, and the reaction was continued with stirring for 180 minutes. After the vanadium precipitation reaction was completed, the solid-liquid separation was carried out to obtain high-purity ammonium metavanadate and a secondary vanadium precipitation mother liquor. The high-purity ammonium metavanadate was oxidatively calcined in a muffle furnace at 550°C for 240 minutes to obtain high-purity vanadium oxide.

[0050] Table 2 Data table of changes in main components of carbonation leaching solution and vanadium products in Example 2

[0051]

[0052]

[0053] Example 3

[0054] Take 800mL of carbonated leaching solution (V 41.94g / L, Na 41.80g / L, Si 0.25g / L, K 0.34g / L, P 0.11g / L, Fe 0.16g / L, Ca 0.02g / L, Cr 0.001g / L, Al 0.001g / L, CO3 2- 87.64 g / L and pH 9.52), heated in a water bath to 70°C, added 0.67 g of sodium metaaluminate according to an Al / Si molar ratio of 1.15, and stirred for 40 minutes; after the desiliconization reaction, solid-liquid separation was completed to obtain desiliconized slag and desiliconized liquid;

[0055] According to the NH4 +NH4VO3 was added to the solution after silicon removal, 93.8 g, at a water bath temperature of 20℃, and stirred for 270 min to carry out the first vanadium precipitation; after the vanadium precipitation reaction was completed, solid-liquid separation was carried out to obtain crude ammonium metavanadate and a first vanadium precipitation mother liquor; the crude ammonium metavanadate was slurried with 1600 mL of pure water, heated to 90℃ in a water bath, and stirred for 30 min at constant temperature to carry out solid-liquid separation to obtain a filtrate; then, 0.8 g of sodium aluminate was added to the filtrate according to the amount of co-precipitation agent 0.5 g / L, and stirring was continued for 30 min, and solid-liquid separation and washing were carried out to remove iron residues to obtain an ammonium metavanadate solution;

[0056] According to the complexing agent concentration 0.7 g / L, 1.12 g of EDTA was added to the ammonium metavanadate solution, the water bath was cooled to 20℃, then 36 g of ammonium bicarbonate was added, and stirring was continued for 180 min; after the vanadium precipitation reaction was completed, solid-liquid separation was carried out to obtain high-purity ammonium metavanadate and a second vanadium precipitation mother liquor; the high-purity ammonium metavanadate was calcined at 550℃ in a muffle furnace for 240 min to obtain high-purity vanadium oxide.

[0057] Table 3 Data table of main component changes of carbonated leaching solution and vanadium products in Example 3

[0058] Material name V Na Cr Si P Fe K Ca Al Carbonated leach solution (g / L) 41.94 41.80 0.001 0.25 0.11 0.16 0.34 0.02 0.001 Post-silica removal solution (g / L) 41.68 41.42 0.001 0.002 0.01 0.15 0.33 0.02 0.046 Crude ammonium metavanadate (wt%) 43.38 0.024 0.001 0.002 0.002 0.097 0.023 0.012 0.028 Ammonium metavanadate solution (g / L) 19.42 0.011 <0.001 0.001 0.001 0.001 0.010 0.005 0.002 High purity vanadium oxide (wt%) 55.91 0.003 0.001 0.002 0.001 0.002 0.003 0.002 0.002

[0059] According to the above data, the method provided by the application for preparing high-purity vanadium oxide from carbonated leaching solution by deep impurity removal can sequentially carry out deep desilication, precipitate crude ammonium metavanadate to achieve deep desilication, and separate phosphorus and most of potassium, sodium and other impurities; the crude ammonium metavanadate is slurried with pure water, heated and dissolved, and deep separation of iron, potassium, sodium, calcium and other cations is carried out by complexing cooling crystallization, and finally high-purity vanadium pentoxide is prepared; the method has the characteristics of simple process flow, low reagent consumption and low cost, and provides a new way for preparing high-purity vanadium oxide from carbonated leaching solution.

[0060] The above description of the embodiments is only used to help understand the method of the application and its core idea. It should be pointed out that for ordinary skilled persons in the art, some improvements and modifications can be made to the application without departing from the principles of the application, and these improvements and modifications also fall within the protection scope of the claims of the application.

[0061] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the application will not be limited to the embodiments shown herein, but will conform 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 leachate, comprising the following steps: S1, adding aluminum salt to the carbonated leachate to remove silicon, and separating the solid and liquid to obtain desiliconized slag and desiliconized liquid; S2, mixing the desiliconized liquid and ammonium salt, and separating the solid and liquid after vanadium precipitation to obtain crude ammonium metavanadate and a primary vanadium precipitation mother liquor; S3, re-dissolving the crude ammonium metavanadate, stirring the obtained crude ammonium metavanadate re-dissolved slurry for reaction, and obtaining iron removal slag and ammonium metavanadate solution after solid-liquid separation; S4, adding a complexing agent and an ammonium salt to the ammonium metavanadate solution to precipitate vanadium, and obtaining high-purity ammonium metavanadate and a secondary vanadium precipitation mother liquor after solid-liquid separation; S5. calcining the high-purity ammonium metavanadate at high temperature to obtain high-purity vanadium pentoxide.

2. The method according to claim 1, characterized in that In step S1, the aluminum salt includes sodium aluminate, and the amount of sodium aluminate added is according to an Al:Si molar ratio of (1.05-1.2):1; and / or the desiliconization temperature is 30-100°C, and the desiliconization time is 30-60 minutes.

3. The method according to claim 1, characterized in that In step S2, the ammonium salt includes one or more of ammonium carbonate, ammonium bicarbonate and ammonia water, and / or the amount of the ammonium salt added is based on the amount of NH4 in the vanadium precipitation solution. + The molar ratio of V is 2.5 to 3.5:1, and / or the temperature of the vanadium precipitation is 15 to 30° C., and the time of the vanadium precipitation is 100 to 300 minutes.

4. The method according to claim 1, wherein In step S3, the re-dissolution is specifically as follows: The crude ammonium metavanadate and water are mixed and slurried, and then heated at a heating temperature of 80-100°C.

5. The method according to claim 4, characterized in that The solid-liquid ratio of the crude ammonium metavanadate and the water is 1 g: (19-25) mL.

6. The method according to claim 1, characterized in that In step S3, the stirring reaction is specifically: stirring the crude ammonium metavanadate re-dissolve slurry at 90-100° C. for 60-180 min; or, adding a coprecipitant to the crude ammonium metavanadate re-dissolve slurry and stirring at 80-100° C. for 10-60 min, wherein the coprecipitant includes sodium metaaluminate, and the amount of the coprecipitant added is 0.1-0.6 g / L of the crude ammonium metavanadate re-dissolve slurry.

7. The method according to claim 6, characterized in that In step S3, before adding the co-precipitate, the step further includes: The crude ammonium metavanadate slurry is dissolved back to separate the iron slag.

8. The method according to claim 1, characterized in that In step S4, the amount of the complexing agent added is controlled according to the complexing agent concentration of 0.5 to 1 g / L in the ammonium metavanadate solution; and / or, before the ammonium salt precipitation, the process further comprises: cooling the ammonium metavanadate solution to 20 to 35°C; and / or, the complexing agent comprises EDTA, and the ammonium salt comprises one or both of ammonium carbonate and ammonium bicarbonate; and / or, the amount of the ammonium salt added is controlled according to NH4 + The concentration is controlled at 3-6g / L.

9. The method according to claim 1, characterized in that In step S5, the high-temperature calcination temperature is 500-800° C. and the time is 5-10 hours.

10. The method according to any one of claims 1 to 9, characterized in that The carbonated 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. The carbonated leaching solution contains V≥15g / L, Na≥30g / L, CO3 2- ≥40g / L, Si≥0.15g / L, K≥0.2g / L, Fe≥0.05g / L, Ca≥0.01g / L, Cr≤0.02g / L.

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