Method for directly separating ferrovanadium from ferrovanadium coexisting acid liquor in one step

Abstract

The invention belongs to the technical field of ferrovanadium separation treatment, and particularly relates to a method for directly separating ferrovanadium from ferrovanadium coexisting acid liquor in one step. The method comprises the following steps that the temperature of pickle liquor containing iron and vanadium is increased, a reducing agent is added for partial reduction, the reduction time ranges from 30 min to 60 min, alkali liquor serves as a precipitator, a continuous equal-pH precipitation method is adopted for ferrovanadium precipitation separation, the pH control range ranges from 10 to 14, the reaction time ranges from 10 min to 60 min, the vanadium-containing solution and the magnetic slag are separated through a magnetic separation method, the iron precipitation rate reaches 99% or above, and the vanadium-containing solution and the magnetic slag are separated. And the vanadium precipitation rate is lower than 1%.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical separation, and relates to the technical field of a method for directly separating vanadium iron from vanadium iron coexisting acid solution in one step. Background Art

[0002] In order to recycle vanadium in secondary resources, acid leaching is often used to leach vanadium into solution, and then carry out subsequent treatment. During the acid leaching process, a large number of associated elements including vanadium are also leached into the solution, among which iron is the most important impurity ion.

[0003] At present, the main industrial vanadium extraction process is chemical precipitation, including hydrolysis vanadium precipitation, ammonium salt vanadium precipitation, calcium salt vanadium precipitation, and iron salt vanadium precipitation. These methods are all primary enrichment methods and cannot directly separate vanadium. Among them, iron salt vanadium precipitation is often widely used as a method for enriching vanadium in vanadium-iron coexisting solutions. As a product of iron salt vanadium precipitation, vanadium iron slag has a large amount of product slag, low purity, and low value. If the vanadium is to be recovered, the vanadium iron slag needs to be further treated for a secondary treatment to achieve the separation and recovery of vanadium and iron. The current method for separating vanadium and iron from vanadium-iron coexisting solutions has a long process flow, and the process parameters are many and complex, which is not conducive to large-scale industrial applications.

[0004] Therefore, it is urgent to develop a method for directly separating vanadium iron from vanadium iron coexisting acid solution in one step. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a method for directly separating ferrovanadium from ferrovanadium coexisting acid solution in one step.

[0006] To achieve the above object, the present invention is implemented by the following technical solutions:

[0007] The present invention provides a method for directly separating ferrovanadium from ferrovanadium coexisting acid solution in one step, the method comprising the following steps:

[0008] The acid leaching solution containing iron and vanadium is heated to 50-70°C, and a reducing agent is added for partial reduction. The reduction time is 30-60 minutes. Alkaline solution is used as a precipitant, and a continuous equal pH precipitation method is used to precipitate iron. The solid-liquid separation obtains a vanadium-containing filtrate and iron slag. The iron precipitation rate is more than 99%, and the vanadium precipitation rate is less than 1%.

[0009] The present invention adopts a partial reduction method to make the iron in the solution coexist as ferric iron and ferrous iron, and adopts an equal pH continuous precipitation method to precipitate iron. The pH of the precipitation system is stable, and the prepared magnetic ferrosoferric oxide particles are uniform and have good crystal form, while vanadium is still retained in the solution in the form of anions. The vanadium-containing solution and the iron slag are effectively separated by magnetic separation. The one-step method directly realizes the separation and purification of vanadium and iron, solves the problem of difficult filtration caused by the initial enrichment of vanadium by iron salt precipitation to obtain vanadium iron slag and alkali dissolution of vanadium iron slag, improves the separation effect of vanadium and iron, simplifies the process flow, reduces the difficulty of operation, and is suitable for large-scale industrial production.

[0010] Further, the molar ratio of iron to vanadium in the acid leaching solution containing iron and vanadium is 1:10 to 10:1;

[0011] Further, the reducing agent is one or a combination of two of sodium sulfite, sodium pyrosulfite and sodium dithionite;

[0012] Further, the reducing agent is used in an amount such that the molar ratio of the reducing agent to iron is 0.2 to 1:1;

[0013] Furthermore, the alkali solution used as the precipitant is one or a combination of two of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate solution;

[0014] Furthermore, the pH control range of the iso-pH precipitation method is 10 to 14;

[0015] Furthermore, the reaction time of the iso-pH precipitation method is 10 to 60 minutes;

[0016] Furthermore, the solid-liquid separation method is magnetic separation;

[0017] Furthermore, the iron precipitation rate obtained through the above steps is more than 99%, and the vanadium precipitation rate is less than 1%.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The one-step method realizes the direct separation of iron and vanadium in the acid leaching solution, improves the efficiency of vanadium and iron separation, simplifies the process flow, reduces the difficulty of operation, and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the solid-liquid separation of the co-flow precipitation slurry under magnetic field conditions before and after the present invention;

[0021] Figure 2 It is a comparative schematic diagram of the co-flow sedimentation slurry before and after solid-liquid separation under magnetic field conditions in the comparative example of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can implement the invention with reference to the description. However, the following embodiments are only simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0023] Example 1

[0024] A method for directly separating ferrovanadium from ferrovanadium coexisting acid solution in one step comprises the following steps:

[0025] The acid leaching solution containing iron and vanadium is heated to 70°C, wherein the molar ratio of iron to vanadium in the acid solution is 1:1, sodium sulfite is added as a reducing agent, the molar ratio of sodium sulfite to iron is 1:1, the reduction time is 60 minutes, sodium hydroxide solution is used as a precipitant, and the continuous equal pH precipitation method is used to precipitate iron, the pH is stabilized at 12, the reaction time is 20 minutes, and a magnetic separation method is used for solid-liquid separation to obtain a vanadium-containing filtrate and iron slag, the iron precipitation rate is 99.7%, and the vanadium precipitation rate is 0.8%.

[0026] Example 2

[0027] A method for directly separating ferrovanadium from ferrovanadium coexisting acid solution in one step comprises the following steps:

[0028] The acid leaching solution containing iron and vanadium is heated to 70°C, wherein the molar ratio of iron to vanadium in the acid solution is 5:1, sodium pyrosulfite is added as a reducing agent, the molar ratio of sodium pyrosulfite to iron is 0.8:1, the reduction time is 40 minutes, sodium hydroxide solution is used as a precipitant, and the continuous equal pH precipitation method is used to precipitate iron, the pH is stabilized at 11, the reaction time is 10 minutes, and a magnetic separation method is used for solid-liquid separation to obtain a vanadium-containing filtrate and iron slag, the iron precipitation rate is 99.8%, and the vanadium precipitation rate is 0.5%.

[0029] Example 3

[0030] A method for directly separating ferrovanadium from ferrovanadium coexisting acid solution in one step comprises the following steps:

[0031] The acid leaching solution containing iron and vanadium is heated to 70°C, wherein the molar ratio of iron to vanadium in the acid solution is 1:5, sodium dithionite is added as a reducing agent, the molar ratio of sodium dithionite to iron is 0.7:1, the reduction time is 30 minutes, sodium hydroxide solution is used as a precipitant, and the continuous equal pH precipitation method is used to precipitate iron, the pH is stabilized at 11, the reaction time is 15 minutes, and a magnetic separation method is used for solid-liquid separation to obtain a vanadium-containing filtrate and iron slag, the iron precipitation rate is 99.8%, and the vanadium precipitation rate is 0.7%.

[0032] Comparative Example 1

[0033] Compared with Example 1, the difference is that no reduction treatment is performed, and the remaining steps and parameters are the same. The magnetic separation method cannot achieve solid-liquid separation of the alkali-soluble slurry, the atmospheric pressure filtration speed is slow, and it is difficult to wash. The iron precipitation rate is 99.8%, and the vanadium precipitation rate is 75.2%.

[0034] The applicant declares that the present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that the equivalent replacement of the raw materials 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.

Claims

1. A method for directly separating ferrovanadium from ferrovanadium coexisting acid solution in one step, characterized by comprising the following steps: The acid leaching solution containing iron and vanadium is heated to 50-70°C, and a reducing agent is added for partial reduction. The reduction time is 30-60 minutes. Alkaline solution is used as a precipitant, and a continuous equal pH precipitation method is used to precipitate iron. The solid-liquid separation obtains a vanadium-containing filtrate and iron slag. The iron precipitation rate is more than 99%, and the vanadium precipitation rate is less than 1%.

2. A method for directly separating ferrovanadium from ferrovanadium coexisting acid solution according to claim 1, characterized in that: The molar ratio of iron to vanadium in the acid leaching solution containing iron and vanadium is 1:10 to 10:

1.

3. A method for directly separating ferrovanadium from ferrovanadium coexisting acid solution according to claim 1, characterized in that: The reducing agent is one or a combination of two of sodium sulfite, sodium pyrosulfite and sodium dithionite.

4. The method for directly separating ferrovanadium from ferrovanadium coexisting acid solution according to claim 1, characterized in that: The amount of the reducing agent is such that the molar ratio of the reducing agent to iron is 0.2 to 1:

1.

5. The method for directly separating ferrovanadium from ferrovanadium coexisting acid solution according to claim 1, characterized in that: The alkali solution used as the precipitant is one or a combination of two of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate solutions.

6. The method for directly separating ferrovanadium from ferrovanadium coexisting acid solution according to claim 1, characterized in that: The pH control range of the iso-pH precipitation method is 10-14.

7. The method for directly separating ferrovanadium from ferrovanadium coexisting acid solution according to claim 1, characterized in that: The reaction time of the iso-pH precipitation method is 10 to 60 minutes.

8. The method for directly separating ferrovanadium from ferrovanadium coexisting acid solution according to claim 1, characterized in that: The solid-liquid separation method is magnetic separation.

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