Alkaline vanadium liquid selective desiliconization method

Abstract

The invention discloses a selective desiliconization method for alkaline vanadium liquid. According to the process, magnesium-aluminum hydrotalcite prepared in advance is introduced into the alkaline vanadium liquid, the pH does not need to be regulated and controlled, silicon can be selectively adsorbed, desilicication slag is desorbed and then recycled as a desilicication agent, and a sodium silicate-containing solution can be used for preparing a water glass product. According to the method for deeply adsorbing silicon in the alkaline vanadium liquid by adopting the magnesium-aluminum hydrotalcite, various conditions of an existing process are not greatly changed, disturbance to existing industrial production is small, meanwhile, the problems that the desilicication limit of the alkaline vanadium liquid is insufficient and vanadium loss is high at present can be solved, silicon in the alkaline vanadium liquid can be reduced to 30 mg / L or below, and the requirements of vanadium products are met.

Description

Technical Field

[0001] The present invention relates to the field of vanadium product production, and particularly to a method for selectively removing silicon from alkaline vanadium solution. Background Art

[0002] Vanadium, as an important strategic resource, is widely used in fields such as aerospace, chemical industry, and iron and steel.

[0003] Vanadium-titanium magnetite is the main raw material mineral for vanadium extraction, accounting for about 88% of the total vanadium output. Vanadium slag, also known as converter slag, is produced by melting vanadium-titanium magnetite through blast furnace and converter. After sodium roasting - water leaching of vanadium slag, alkaline vanadium solution is obtained, and its main impurities are Cr(IV) and Si(IV) impurities, which will affect the purity of vanadium products. During the vanadium precipitation process, Cr(VI) in the solution can be effectively removed, while the treatment of silicon remains challenging.

[0004] At present, the methods for removing silicon from alkaline vanadium solution mainly include chemical precipitation method, solvent extraction method, ion exchange method, adsorption method, etc. The main method for removing silicon from alkaline vanadium solution industrially is to introduce aluminum salts, magnesium salts, etc. to form precipitates with silicon for removal. However, this results in a large loss of vanadium. There is an urgent need to develop a method for selectively removing silicon from alkaline vanadium solution. Summary of the Invention

[0005] The present invention discloses a method for selectively removing silicon from alkaline vanadium solution. During the process of removing silicon from alkaline vanadium solution, a certain amount of magnesium-aluminum hydrotalcite is added, and silicon is adsorbed by relying on the ion exchange effect, and the reaction conditions are controlled to achieve the purpose of selective silicon removal.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for selectively removing silicon from alkaline vanadium solution, the method comprising the following steps:

[0008] (1) Vanadium-titanium magnetite is smelted through blast furnace and converter to produce converter slag, and then alkaline vanadium solution is obtained through different roasting and leaching processes;

[0009] Preferably, the alkaline vanadium solution comprises: NaVO3 ~ 30 g / L (calculated as V), Na2SiO3 ~ 1200 mg / L (calculated as Si); Na2CrO4 ~ 1.2 g / L (calculated as Cr);

[0010] (2) Adding magnesium-aluminum hydrotalcite to the alkaline vanadium solution to selectively adsorb silicon

[0011] In step (2), the concentration of magnesium-aluminum hydrotalcite added varies within the range of 0.5 - 10 g / L, such as 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 g / L, etc., and preferably 2 - 8 g / L in the actual operation of the present invention.

[0012] In step (2), the reaction temperature varies within the range of 30 - 90 °C, such as 30, 45, 60, 75, 90 °C, etc., and in the actual operation of the present invention, it is preferably 30 - 80 °C.

[0013] In step (2), the aging time varies within the range of 0 - 480 min, such as 0, 10, 20, 30, 60, 120, etc., and in the actual operation of the present invention, it is preferably 120 - 480 min.

[0014] In step (2), the stirring rate varies within the range of 50 - 400 rpm, such as 50, 100, 200, 300, 400, etc., and in the actual operation of the present invention, it is preferably 200 - 400 rpm.

[0015] (3) The desilicated slag can be used as a raw material for water glass after desorption treatment to dissolve silicon, and the remaining slag can be regenerated into magnesium - aluminum hydrotalcite and reused as a desilication agent.

[0016] In step (3), the desorbing agent added is any one or at least two components selected from sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, etc., and preferably sodium hydroxide and sodium carbonate.

[0017] In step (3), the concentration of the desorbing agent varies within the range of 1 - 20 g / L, such as 1, 3, 5, 8, 10, 12, 15, 18, 20, etc., and in the actual operation of the present invention, it is preferably 5 - 10 g / L.

[0018] In step (3), the liquid - solid ratio of the desorption varies within the range of 2 - 30, such as 2, 4, 6, 8, 12, 16, 18, 20, 25, 30, etc., and in the actual operation of the present invention, it is preferably 9 - 20.

[0019] In step (3), the reaction temperature varies within the range of 30 - 90 °C, such as 30, 45, 60, 75, 90 °C, etc., and in the actual operation of the present invention, it is preferably 30 - 90 °C.

[0020] In step (3), the reaction time varies within the range of 0 - 360 min, such as 0, 10, 20, 30, 60, 120, 180, 240, 360, etc., and in the actual operation of the present invention, it is preferably 60 - 120 min.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The selective desilication method of the present invention can selectively adsorb and desilicate by adding low - cost magnesium - aluminum hydrotalcite through ion - exchange, and can reduce the silicon in the alkaline vanadium solution to less than 20 mg / L (calculated as Si), meeting the requirements of vanadium products;

[0023] (2) After the desilication residue of the present invention is desorbed, the adsorbed silicon is separated and can be used as a raw material for water glass. At the same time, the desilication residue is regenerated into magnesium-aluminum hydrotalcite and reused as a desilication agent.

[0024] (3) The selective desilication method of the present invention not only has mild conditions, does not require high temperature and pressure, and will not form harmful substances with vanadium, but also has the advantages of simple process and low production cost. Description of the Drawings

[0025] Figure 1 is the process flow chart of the selective desilication of alkaline vanadium solution of the present invention. Detailed Embodiments

[0026] Example 1

[0027] Add 2 g / L magnesium-aluminum hydrotalcite solution to 250 ml of vanadium-silicon solution, NaVO3 (30 g / L, V), Na2SiO3 (1200 mg / L, Si), stir in a constant temperature water bath at a speed of 400 r / min, at a temperature of 75 °C and a time of 480 min, to obtain a purified solution and a desilication residue.

[0028] Example 2

[0029] Add 4 g / L magnesium-aluminum hydrotalcite to 250 ml of vanadium-silicon solution, NaVO3 (30 g / L, V), Na2SiO3 (1200 mg / L, Si), stir in a constant temperature water bath at a speed of 400 r / min, at a temperature of 75 °C, to obtain a purified solution and a desilication residue.

[0030] Example 3

[0031] Add 6 g / L magnesium-aluminum hydrotalcite to 250 ml of vanadium-silicon solution, NaVO3 (30 g / L, V), Na2SiO3 (1200 mg / L, Si), stir in a constant temperature water bath at a speed of 400 r / min, at a temperature of 75 °C and a time of 480 min, to obtain a purified solution and a desilication residue.

[0032] Example 4

[0033] Add 6 g / L magnesium-aluminum hydrotalcite to 250 ml of vanadium-silicon solution, NaVO3 (30 g / L, V), Na2SiO3 (1200 mg / L, Si), stir in a constant temperature water bath at a speed of 400 r / min, at a temperature of 30 °C and a time of 480 min, to obtain a purified solution and a desilication residue.

[0034] Example 5

[0035] 6 g / L of magnesium-aluminum hydrotalcite was added to 250 ml of a vanadium-silicon solution containing NaVO3 (30 g / L, V) and Na2SiO3 (1200 mg / L, Si), and the mixture was stirred at a speed of 400 r / min in a constant-temperature water bath at 90 °C for 480 min to obtain a purified solution and desilication slag.

[0036] Example 6

[0037] 6 g / L of magnesium-aluminum hydrotalcite was added to 250 ml of a vanadium-silicon solution containing NaVO3 (30 g / L, V) and Na2SiO3 (1200 mg / L, Si), and the mixture was stirred at a speed of 400 r / min in a constant-temperature water bath at 90 °C for 60 min to obtain a purified solution and desilication slag.

[0038] Example 7

[0039] 6 g / L of magnesium-aluminum hydrotalcite was added to 250 ml of a vanadium-silicon solution containing NaVO3 (30 g / L, V) and Na2SiO3 (1200 mg / L, Si), and the mixture was stirred at a speed of 400 r / min in a constant-temperature water bath at 90 °C for 240 min to obtain a purified solution and desilication slag.

[0040] Example 8

[0041] 6 g / L of magnesium-aluminum hydrotalcite was added to 250 ml of a vanadium-silicon solution containing NaVO3 (30 g / L, V) and Na2SiO3 (1200 mg / L, Si), and the mixture was stirred at a speed of 50 r / min in a constant-temperature water bath at 90 °C for 480 min to obtain a purified solution and desilication slag.

[0042] Example 9

[0043] 6 g / L of magnesium-aluminum hydrotalcite was added to 250 ml of a vanadium-silicon solution containing NaVO3 (30 g / L, V) and Na2SiO3 (1200 mg / L, Si), and the mixture was stirred at a speed of 200 r / min in a constant-temperature water bath at 90 °C for 480 min to obtain a purified solution and desilication slag.

[0044] Example 10

[0045] 1 g of the desilication slag under the optimal reaction conditions was added to 9 ml of NaOH, and the mixture was stirred at a speed of 400 r / min in a constant-temperature water bath. Desorption was carried out under the conditions of a NaOH concentration of 5 g / L, a temperature of 90 °C, a reaction time of 2 h, and a liquid-solid ratio of 9:1 to obtain a desorbed solution and desorbed slag.

[0046] Example 11

[0047] Add 1 g of desilication slag under the optimal reaction conditions to 9 ml of NaOH, stir in a constant temperature water bath at a speed of 400 r / min, and carry out desorption under the conditions of controlling the NaOH concentration at 10 g / L, the temperature at 90 °C, the reaction time at 2 h, and the liquid-solid ratio at 9:1 to obtain a desorption solution and desorption slag.

[0048] Example 12

[0049] Add 1 g of desilication slag under the optimal reaction conditions to 9 ml of NaOH, stir in a constant temperature water bath at a speed of 400 r / min, and carry out desorption under the conditions of controlling the NaOH concentration at 5 g / L, the temperature at 30 °C, the reaction time at 2 h, and the liquid-solid ratio at 9:1 to obtain a desorption solution and desorption slag.

[0050] Example 13

[0051] Add 1 g of desilication slag under the optimal reaction conditions to 9 ml of NaOH, stir in a constant temperature water bath at a speed of 400 r / min, and carry out desorption under the conditions of controlling the NaOH concentration at 5 g / L, the temperature at 90 °C, the reaction time at 0.5 h, and the liquid-solid ratio at 9:1 to obtain a desorption solution and desorption slag.

[0052] Example 14

[0053] Add 1 g of desilication slag under the optimal reaction conditions to 2 ml of NaOH, stir in a constant temperature water bath at a speed of 400 r / min, and carry out desorption under the conditions of controlling the NaOH concentration at 5 g / L, the temperature at 90 °C, the reaction time at 2 h, and the liquid-solid ratio at 2:1 to obtain a desorption solution and desorption slag.

[0054] The applicant declares that the present invention uses the above examples to illustrate the detailed method of the present invention, but the present invention is not limited to the above detailed method, that is, it does not mean that the present invention must rely on the above detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0055] Table 1 Residual silicon concentration in the purified solution of the examples

[0056] Serial number Si(IV) (mg / L) Removal rate of Si(IV) % Example 1 261 78.25 Example 2 71.8 94.02 Example 3 40.5 96.63 Example 4 277.5 76.88 Example 5 31.0 97.42 Example 6 133.1 88.91 Example 7 121 89.92 Example 8 102.3 91.48 Example 9 63.1 94.74

[0057] Table 2 Desorption efficiency of desilication slag in the examples

[0058] Serial number Desorption rate of Si(IV) % Example 10 82.3 Example 11 91.3 Example 12 54.2 Example 13 70.6 Example 14 63.7

[0059] It can be seen from the comparison of Examples 1-3 that as the addition amount of magnesium aluminum hydrotalcite increases, the effect of removing silicon from the alkaline vanadium solution gradually enhances; when the addition amount reaches 6 g / L, the concentration of Si(IV) in the purified solution can be reduced to 40.5 mg / L, and the removal efficiency of Si(IV) is 96.63%.

[0060] It can be seen from the comparison of Examples 3-5 that as the temperature increases, the effect of removing silicon from the alkaline vanadium leaching solution enhances; when the temperature reaches 90 °C, the concentration of Si(IV) in the purified solution is 31.0 mg / L, and the removal efficiency of Si(IV) is 97.42%.

[0061] It can be seen from the comparison of Examples 5-7 that as the desilication reaction time prolongs, the effect of removing silicon from the alkaline vanadium leaching solution enhances; it can be seen from the comparison of Examples 5, 8, and 9 that as the stirring rate of the desilication reaction increases, the effect of removing silicon from the alkaline vanadium leaching solution enhances, which may be due to the enhanced mixing effect.

[0062] It can be seen from the comparison of Examples 10 and 11 that as the concentration of NaOH in the desorbing solution gradually increases, the desorbing effect gradually improves.

[0063] It can be seen from the comparison of Examples 10 and 12 that as the desorbing temperature gradually increases, the desorbing effect gradually improves.

[0064] It can be seen from the comparison of Examples 10 and 13 that as the desorbing time prolongs, the desorbing effect gradually improves.

[0065] It can be seen from the comparison of Examples 10 and 14 that as the liquid-solid ratio increases, the desorbing effect gradually improves.

[0066] It can be seen from the above-mentioned examples that the desilication method described in the present invention can selectively remove silicon from the alkaline vanadium solution.

Claims

1. A method for selective desiliconization of alkaline vanadium liquid, characterized in that: The method comprises the following steps: (1) After smelting in a blast furnace and a converter, vanadium-containing leaching solution is obtained by producing converter slag from vanadium-titanium magnetite through different roasting and leaching processes. This method uses an alkaline vanadium leaching solution of sodium roasting and water leaching. Wherein, the alkaline vanadium leaching solution includes: NaVO3~30g / L (in terms of V), Na2SiO3~1200mg / L (in terms of Si); Na2CrO4~1.2g / L (in terms of Cr).

2. The method according to claim 1, characterized in that After step (1), the following step (2) is performed: (2) Add a certain amount of magnesium aluminum hydrotalcite to the alkaline vanadium solution to selectively adsorb silicon through ion exchange.

3. The method according to claim 2, characterized in that After step (2), the following step (3) is performed: (3) The desiliconization slag is subjected to a desorption treatment to selectively dissolve silicon for reuse, and the slag is reused as a desiliconization agent.

4. The method according to any one of claims 1 to 3, characterized in that: Preferably, the concentration of the desiliconizing agent magnesium aluminum hydrotalcite in the alkaline vanadium solution in step (2) is 0.5 g / L-10 g / L; Preferably, the reaction temperature in step (2) is 30-95°C; Preferably, the reaction time in step (2) is 0-480 min; Preferably, the reaction in step (2) is carried out under stirring at a rate of 50-400 rpm. Preferably, the desorbent in step (3) is any one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, etc., or a combination of at least two thereof; Preferably, the concentration of the desorbent in step (3) is 1-20 g / L Preferably, the desorption liquid-to-solid ratio in step (3) is 2-30 Preferably, the desorption temperature in step (3) is 30-90°C; Preferably, the desorption time in step (3) is 0-360 min.

5. The method according to any one of claims 1 to 4, characterized in that: Green separation includes the following steps: (1) After vanadium-titanium magnetite is smelted in a blast furnace and a converter, converter slag is produced, and then alkaline vanadium leaching solution is obtained through a roasting and leaching process; (2) A certain amount of desiliconizing agent magnesium aluminum hydrotalcite is added to the alkaline vanadium liquid to maintain the concentration at 0.5-10 g / L, without adjusting the pH, the reaction temperature is 30-95°C, the reaction time is 0-480 min, and the stirring speed is 50-400 rpm to selectively adsorb silicon, thereby achieving selective desiliconization in the alkaline vanadium liquid. (3) Adding sodium hydroxide, sodium carbonate, potassium hydroxide, etc. to the desiliconized slag, controlling the concentration at 1-20 g / L, the reaction temperature at 30-90° C., the reaction time at 0-360 min, and the reaction liquid-to-solid ratio at 2-30; filtering after the reaction, the desorption liquid containing sodium silicate can be used as a raw material for preparing water glass, and the slag can achieve the regeneration of magnesium aluminum hydrotalcite and can be reused.

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