Preparation method and application of vanadium liquid desiliconizing agent

Abstract

The present invention belongs to the field of synthesis of fine chemicals and separation and purification of solutions, and relates to a preparation method and application of a vanadium liquid desiliconizer. The present invention can remove silicon without introducing heteroanions, and has great application value in the desiliconization of weakly alkaline vanadium liquid. The specific scheme is: prepare Mg-containing vanadium liquid by electrolyzing Mg sheets in silicon-free vanadium liquid. 2+ Silicon remover, by adding solid HVO3, Na3VO4, NaVO3 to adjust the pH value, the silicon remover can react with silicon-containing vanadium liquid to form Mg x (SiO3) y , and then removed after heating and precipitation, achieving the effect of silicon removal. The present invention solves the problem of introducing other anionic impurities by preparing the silicon removal agent through electrolytic reaction in silicon-free vanadium liquid. At the same time, the solid and liquid phases can be separated by precipitation, centrifugation, filtration or elution. The silicon removal rate can reach over 95%, with a high silicon removal effect.

Description

Technical Field

[0001] The invention belongs to the field of synthesis of fine chemicals and solution separation and purification, and relates to a preparation method of a vanadium liquid desiliconizing agent and application thereof. Background Art

[0002] Vanadium plays a vital role in the industrial field and strategic resources, especially in aerospace, steel smelting, petrochemicals, military manufacturing, industrial catalysis, liquid flow batteries and other industries. Among them, the main raw materials for vanadium extraction are vanadium slag, vanadium titanium magnetite and vanadium-containing phosphorus block ore. [Ren Xueyou. Application status and market prospects of metallic vanadium [J]. World Nonferrous Metals, 2004, (2): 34.] The main industrialized extraction processes currently in place include roasting-water leaching for vanadium extraction, calcification roasting-alkali leaching for vanadium extraction, molten vanadium slag oxidation for vanadium extraction, and direct sulfuric acid leaching for vanadium extraction. However, no matter which process is used to extract vanadium, the purity of the target product must be considered, and impurity ions must be removed to obtain qualified products. Therefore, a purification process is involved in the purification process.

[0003] Based on the alkaline vanadium solution obtained by the sodium roasting-water leaching process, the corresponding impurity removal process is to remove silicon by static precipitation. However, this method requires a long static time. At the same time, fine SiO2 gel will remain during the static process, which is not only difficult to remove by filtration, but also adsorbs a certain amount of vanadium oxyclusive clusters, resulting in vanadium loss. In addition, although MgSO4 and Al2(SO4)3 can be used as desiliconizing agents in alkaline vanadium solution to effectively remove silicon, this method still has the disadvantage of a long static time (ZhangX, Zou XY. Research on desilicating process of liquid containing vanadium [J]. Inorganic Chemicals Industry, 2008, 40 (4): 41). Secondly, it is easy to form insoluble substances such as magnesium vanadate or magnesium aluminate. Thirdly, this method introduces SO4 2- The presence of impurities violates the higher requirement of pure, simple, and small amounts of solutes; fourthly, the elution process after precipitation easily leads to the loss of vanadium ions. However, there are reports of effective silicon removal using polyether in acidic vanadium solutions based on calcination roasting-acid leaching or direct acid leaching. [Xing Xueyong, Li Sijia, Ning Shunming. Research on the desiliconization process of high-silicon stone coal acid leaching solution [J]. Hydrometallurgy, 2011, 30(4): 326.] The amount of silicon removal agent used is small, and the vanadium loss rate is low, but the reaction system is acidic, and a long aging process is still required, and the improvement in filtration effect is not obvious.

[0004] In summary, the main issues are whether the desiliconizer can effectively remove silicon within a defined pH range, whether it introduces other impurities, and minimizing vanadium loss in the vanadium solution to be purified. Given the current state of desiliconization in weakly alkaline systems, an analysis of the alkaline desiliconization mechanism is necessary. Therefore, an effective desiliconizer is needed. Summary of the Invention

[0005] In order to overcome the above problems, the present invention provides a preparation method and application of a vanadium liquid desiliconizer, which can remove silicon without introducing mixed anions and has great application value in the desiliconization of weakly alkaline vanadium liquid. The specific scheme is: prepare Mg-containing vanadium liquid by electrolyzing Mg sheets in a silicon-free vanadium liquid. 2+ Silicon remover, by adding solid HVO3, Na3VO4, NaVO3 to adjust the pH value, the silicon remover can react with silicon-containing vanadium liquid to form Mg x (SiO3) y , and then removed after heating and precipitation to achieve the effect of silicon removal. This method has achieved a high silicon removal effect and found the appropriate silicon removal conditions.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for preparing a vanadium liquid desiliconizer, comprising the following steps:

[0008] Insert the Mg sheet as the anode into the silicon-free vanadium solution, then insert the cathode or inert electrode, and electrolyze under constant voltage or pulse voltage under the action of DC power supply to obtain Mg 2+ A deep orange-red transparent vanadium liquid silicon remover.

[0009] The vanadium solution is one or a mixture of two or more of HVO3, NaVO3 and Na3VO4 solutions; the concentration of the vanadium solution is 10-120 g / L.

[0010] The inert electrode is a carbon electrode, a platinum electrode or a titanium coating electrode.

[0011] The cathode is an Al sheet.

[0012] The DC power supply is a constant voltage of 3-10V or a pulse voltage of 0V to 3-10V for conversion.

[0013] The electrolysis time is 5-30 minutes.

[0014] By using the above electrolysis parameters, the concentration of magnesium ions in the obtained vanadium liquid desiliconizer is below 2 mol / L.

[0015] The application method of the above-mentioned vanadium liquid desiliconizer is as follows:

[0016] The vanadium liquid desiliconizing agent is added to the silicon-containing vanadium liquid to obtain a mixed liquid, and the pH value is adjusted to 6-10; the mixture is reacted under heating and stirring conditions to generate a precipitate, which is then allowed to stand, filtered, and washed to obtain a vanadium liquid that meets the standards after desiliconization.

[0017] In the mixed solution, the molar ratio of magnesium ions to Si ions in the silicon-vanadium liquid is (0.9-1.2):1.

[0018] When adjusting the pH, one or a mixture of two or more solid HVO3, Na3VO4, and NaVO3 is used.

[0019] The stirring time is 15-120 minutes.

[0020] The standing time is more than 90 minutes.

[0021] The heating temperature is 50-70° C., and the heating time is more than 2 hours.

[0022] Beneficial effects of the present invention:

[0023] The method of the present invention uses Mg sheets and vanadium liquid as raw materials to prepare a desiliconizer by electrolysis, and the Mg ion concentration in the solution is controlled by controlling the connection voltage and electrolysis time. Subsequently, by controlling factors such as the pH value of the solution after adding the desiliconizer, the reaction stirring time, the heating temperature, and the precipitation standing time, a high-purity vanadium liquid that meets the standards is finally obtained. The entire preparation process does not discharge waste liquid, does not produce harmful gases, does not cause significant loss of vanadium, and does not burden the environment. Using solid HVO3, Na3VO4, and NaVO3 to adjust the pH value avoids the loss of Mg ions in the desiliconizer caused by common alkaline agents such as NaOH. The electrolysis process directly introduces Mg ions without introducing mixed anions, thereby maximizing the utilization of raw materials and avoiding waste.

[0024] The present invention solves the problem of introducing other anionic impurities by preparing a desiliconizer by electrolytic reaction in silicon-free vanadium liquid. At the same time, the solid and liquid phases can be separated by precipitation, centrifugation, filtration or elution, thereby achieving a high desiliconization effect.

[0025] The present invention adopts electrolysis to prepare the desiliconizing agent, and its precipitation desiliconization rate can reach more than 95%, with good separation effect, fast reaction speed, simple process and green environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a process flow chart of the method of the present invention. DETAILED DESCRIPTION

[0027] The process of the present invention is as follows Figure 1 As shown, the present invention is further described in detail below in conjunction with specific embodiments, but the present invention is not limited to the specific embodiments.

[0028] Example 1

[0029] An appropriate amount of silicon-free vanadium solution (pH around 7.5, concentration 10 g / L) was used as the electrolyte. Sandpaper-polished Al and Mg sheets were placed at the cathode and anode of the electrodes, respectively. A constant voltage of 3 V was applied, and pulsed alternating electrolysis was performed for a specified period to produce a desiliconized solution. Inductively coupled plasma analysis of a sample revealed a Mg concentration of 0.5 g / L in the desiliconized solution, while the silicon concentration in the desiliconized vanadium solution was 1.6 g / L. 36 mL of the desiliconized solution and 10 mL of the desiliconized vanadium solution were mixed in a conical flask to a ratio of Mg:Si = 1.125:1. An appropriate amount of solid NaVO₃ was added to the mixture, the pH adjusted to 8.1, and magnetic stirring was performed for 20 minutes. The solution was then transferred to a 50°C water bath and heated for 120 minutes, yielding a small precipitate. After filtration and washing, the white precipitate was separated from the desiliconized vanadium solution. Testing confirmed a silicon removal rate of 95.47%, meeting the standard.

[0030] Example 2

[0031] An appropriate amount of silicon-free vanadium solution (pH around 7.5, concentration 120 g / L) was used as the electrolyte. Sandpaper-polished inert platinum and magnesium sheets were placed at the cathode and anode, respectively. A constant voltage of 3 V was applied, and pulsed alternating electrolysis was performed for a specified period to produce a desiliconized solution. Inductively coupled plasma analysis of a sample revealed a magnesium concentration of 0.5 g / L in the desiliconized solution, while the silicon concentration in the desiliconized vanadium solution was 1.6 g / L. 96 mL of the desiliconized solution and 25 mL of the desiliconized vanadium solution were mixed in a conical flask to a ratio of Mg:Si of 1.2:1. An appropriate amount of solid HVO₃ was added to the mixture, the pH adjusted to 8.0, and magnetic stirring was performed for 15 minutes. The solution was then transferred to a 55°C water bath, allowed to stand for 100 minutes, and heated for 100 minutes to produce a small precipitate. The white precipitate was filtered and washed, and the desiliconized vanadium solution was separated. Testing confirmed a silicon removal rate of 95.16%, meeting the standard.

[0032] Example 3

[0033] An appropriate amount of silicon-free vanadium solution (pH around 6, concentration 40 g / L) was used as the electrolyte. A sandpaper-polished titanium-coated electrode and a magnesium sheet were placed at the cathode and anode of the electrodes, respectively. A constant voltage of 5 V was applied and the electrolysis was performed for a specified period of time to obtain a desiliconized solution. Inductively coupled plasma analysis of a sample revealed a magnesium concentration of 0.8 g / L in the desiliconized solution, and a silicon concentration of 0.8 g / L in the desiliconized vanadium solution. 25 mL of the desiliconized solution and 25 mL of the desiliconized vanadium solution were mixed in a conical flask to a ratio of Mg:Si = 1:1. An appropriate amount of solid Na₃VO₄ was added to the mixture, the pH adjusted to 8.6, and the solution was stirred under a magnetic stirrer for 30 minutes. The solution was then transferred to a 60°C water bath and heated for 120 minutes, yielding a small precipitate. The white precipitate was then filtered and washed, and the desiliconized vanadium solution was separated. Testing confirmed a silicon removal rate of 96.86%, meeting the standard.

[0034] Example 4

[0035] An appropriate amount of silicon-free vanadium solution (pH around 7.5, concentration 50 g / L) was used as the electrolyte. Sandpaper-polished Al and Mg sheets were placed at the cathode and anode of the electrodes, respectively. A constant voltage of 3 V was applied, and pulsed alternating electrolysis was performed for a specified period to produce a desiliconized solution. Inductively coupled plasma analysis of a sample revealed a Mg concentration of 0.75 g / L in the desiliconized solution, and a silicon concentration of 0.25 g / L in the desiliconized vanadium solution. 15 mL of the desiliconized solution and 50 mL of the desiliconized vanadium solution were mixed in a conical flask to a Me:Si ratio of 0.9:1. An appropriate amount of solid Na₃VO₄ was added to the mixture, the pH adjusted to 8.8, and magnetic stirring was performed for 90 minutes. The solution was then transferred to a 65°C water bath and heated for 150 minutes. A small amount of precipitate was obtained, which was then filtered, washed, and separated into a white precipitate. The desiliconized vanadium solution was then separated. Testing confirmed a silicon removal rate of 95.55%, meeting the standard.

[0036] Example 5

[0037] An appropriate amount of silicon-free vanadium solution (pH around 7.5, concentration 60 g / L) was used as the electrolyte. A sandpaper-polished carbon electrode and a magnesium sheet were placed at the cathode and anode of the electrodes, respectively. A constant voltage of 3 V was applied and the electrolysis was continued for a specified period of time to obtain a desiliconized solution. Inductively coupled plasma analysis of a sample revealed a magnesium concentration of 0.75 g / L in the desiliconized solution, while the silicon concentration in the desiliconized vanadium solution was 0.5 g / L. A 30 mL sample of the desiliconized solution and a 40 mL sample of the desiliconized vanadium solution were mixed in a conical flask to a ratio of Mg:Si = 1.125:1. An appropriate amount of solid NaVO₃ was added to the mixture, the pH adjusted to 9, and the solution was stirred under a magnetic stirrer for 120 minutes. The solution was then transferred to a 70°C water bath and heated for 150 minutes, yielding a small precipitate. The white precipitate was then filtered and washed, and the desiliconized vanadium solution was separated. Testing confirmed a silicon removal rate of 95.68%, meeting the standard.

[0038] Example 6

[0039] An appropriate amount of silicon-free vanadium solution (pH around 10, concentration 60 g / L) was used as the electrolyte. Sandpaper-polished Al and Mg sheets were placed at the cathode and anode of the electrodes, respectively. A constant voltage of 3 V was applied, and pulsed alternating electrolysis was performed for a specified period to produce a desiliconized solution. Inductively coupled plasma analysis of a sample revealed a magnesium concentration of 1.15 g / L in the desiliconized solution, while the silicon concentration in the desiliconized vanadium solution was 0.3 g / L. 15 mL of the desiliconized solution and 50 mL of the desiliconized vanadium solution were mixed in a conical flask to a ratio of Mg:Si = 1.1:1. An appropriate amount of solid HVO₃ was added to the mixture, the pH adjusted to 10, and the solution was stirred under a magnetic stirrer for 60 minutes. The solution was then transferred to a 65°C water bath and heated for 120 minutes, yielding a small precipitate. The precipitate, which turned white after filtration and washing, was then separated from the desiliconized vanadium solution. Testing confirmed a silicon removal rate of 96.72%, meeting the standard.

[0040] Example 7

[0041] An appropriate amount of silicon-free vanadium solution (pH around 7.5, concentration 45g / L) was used as the electrolyte. Sandpaper-polished Al and Mg sheets were placed at the cathode and anode of the electrodes, respectively. A constant voltage of 10V was applied and the electrolysis was continued for a specified period of time to produce a desiliconized solution. Inductively coupled plasma analysis of the sample revealed a Mg concentration of 0.6g / L in the desiliconized solution, while the silicon concentration in the desiliconized vanadium solution was 0.45g / L. 18mL of the desiliconized solution and 20mL of the desiliconized vanadium solution were mixed in a conical flask to a ratio of Mg:Si = 1.2:1. An appropriate amount of solid Na₃VO₄ was added to the mixture, the pH adjusted to 9.5, and the solution was stirred under a magnetic stirrer for 40 minutes. The solution was then transferred to a 60°C water bath and heated for 150 minutes, yielding a small precipitate. The white precipitate was then filtered and washed, and the desiliconized vanadium solution was separated. Testing confirmed a silicon removal rate of 95.92%, meeting the standard.

Claims

1. A method for applying a vanadium liquid desiliconizing agent, characterized in that: The specific steps of the preparation method of the vanadium liquid desiliconizer are as follows: Insert the Mg sheet as the anode into the silicon-free vanadium solution, then insert the cathode Al sheet or inert electrode, and electrolyze under constant voltage or pulse voltage under the action of DC power supply to obtain Mg 2+ Vanadium liquid desiliconizer; The vanadium solution is one or a mixture of two or more of HVO3, NaVO3, and Na3VO4 solutions; The DC power supply is a constant voltage of 3-10V or a pulse voltage of 0V to 3-10V. The specific steps of the application method are: adding the vanadium liquid desiliconizing agent to the silicon-containing vanadium liquid to obtain a mixed solution, adjusting the pH to 8-10; reacting under heating and stirring conditions to produce a precipitate, and filtering and washing the mixture to obtain a vanadium liquid that meets the standards after desiliconization; In the mixed solution, the molar ratio of magnesium ions to Si ions in the silicon-vanadium liquid is (0.9-1.2):1; When adjusting the pH, one or a mixture of two or more solid HVO3, Na3VO4, and NaVO3 is used.

2. The application method according to claim 1, characterized in that: The concentration of the vanadium solution is 10-120 g / L.

3. The application method according to claim 1 or 2, characterized in that: The inert electrode is a carbon electrode, a platinum electrode or a titanium coating electrode.

4. The application method according to claim 1 or 2, characterized in that: The electrolysis time is 5-30 minutes.

5. The application method according to claim 1 or 2, characterized in that: The stirring time is 15-120 minutes; the standing time is more than 90 minutes.

6. The application method according to claim 1 or 2, characterized in that: The heating temperature is 50-70° C., and the heating time is more than 2 hours.

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