A method for removing impurities from the electrolyte cobalt circulating solution

Abstract

The present invention discloses a method for removing impurities from the electrowinning cobalt circulating solution, which comprises the following steps: (1) adsorbing the electrowinning cobalt circulating solution with an adsorption resin to obtain the electrowinning cobalt circulating solution with reduced copper and zinc and the adsorption resin adsorbed with impurities; (2) desorbing the adsorption resin adsorbed with impurities to obtain the desorbed resin and a solution containing copper and zinc; (3) transforming the desorbed resin with liquid caustic soda to obtain the regenerated adsorption resin and a solution containing sodium ions, and the regenerated adsorption resin is returned to step (1) for repeated use. The present invention uses the Duolite CH-90Na resin to adsorb and remove impurities from the electrowinning cobalt circulating solution, and can reduce Cu and Zn in the circulating solution of electrowinning cobalt to below 0.001 g / L, meeting the production requirements. After the adsorption resin is saturated, hydrochloric acid is used to regenerate the adsorbed resin, and finally liquid caustic soda is used to transform the resin. After the transformation is completed, it can be reused.

Description

Technical Field

[0001] The present invention belongs to the technical field of impurity removal from electrowinning solutions, and particularly relates to a method for removing impurities from a cobalt electrowinning circulating solution. Background Art

[0002] Currently, in the production of cobalt electrowinning, diaphragm cathode cobalt is the main production method. The production method of diaphragm cathode cobalt is mainly to continuously pump cobalt chloride solution into a closed diaphragm filter press, pass direct current through the filter press, and finally generate cobalt metal on the cathode in the filter press. During this production process, due to the influence of equipment and environmental factors, other metal impurities are likely to exceed the standard in the circulating solution. Specifically, impurities such as Cu and Zn are easily introduced from the equipment and the environment, resulting in a relatively high content of copper and zinc ions in the cobalt electrowinning circulating solution. Since the electrodeposition precipitation order of copper and zinc is prior to that of cobalt, high impurity levels will affect the main content of electrowon cobalt. Therefore, it is necessary to reduce the impurities in the electrowinning circulating solution to a relatively low level. The traditional impurity removal method generally involves gradually extracting the circulating solution together with the pre-liquid for cobalt extraction through P204 and P507 to obtain a cobalt chloride solution with qualified impurities. This impurity removal method has a long process and high production costs due to the full extraction process, and is not economical. Summary of the Invention

[0003] In view of the problems in the prior art, the present invention provides a method for removing impurities from a cobalt electrowinning circulating solution that can effectively reduce Cu and Zn in the cobalt electrowinning circulating solution.

[0004] The present invention adopts the following technical solutions:

[0005] A method for removing impurities from a cobalt electrowinning circulating solution, characterized in that the method comprises the following steps:

[0006] (1) Adsorb the cobalt electrowinning circulating solution with an adsorption resin to obtain a cobalt electrowinning circulating solution with reduced copper and zinc and an adsorption resin adsorbed with impurities; the liquid-solid ratio of the cobalt electrowinning circulating solution to the adsorption resin is 20 - 30:1;

[0007] (2) Desorb the adsorption resin adsorbed with impurities to obtain a desorbed resin and a solution containing copper and zinc;

[0008] (3) Transform the desorbed resin with liquid caustic soda to obtain a regenerated adsorption resin and a solution containing sodium ions, and the regenerated adsorption resin is returned to step (1) for reuse.

[0009] According to the above method for removing impurities from a cobalt electrowinning circulating solution, it is characterized in that the adsorption resin in step (1) is Duolite CH-90Na resin.

[0010] According to the above-mentioned method for removing impurities from the electrowinning cobalt circulating solution, it is characterized in that the adsorption temperature of the electrowinning cobalt circulating solution with an adsorption resin in step (1) is 40°C - 50°C.

[0011] According to the above-mentioned method for removing impurities from the electrowinning cobalt circulating solution, it is characterized in that the copper content in the electrowinning cobalt circulating solution after reducing copper and zinc in step (1) is less than 0.001 g / L, and the zinc content is less than 0.001 g / L.

[0012] According to the above-mentioned method for removing impurities from the electrowinning cobalt circulating solution, it is characterized in that in step (2), the adsorption resin after adsorbing impurities is desorbed with a hydrochloric acid solution, the concentration of the hydrochloric acid solution is 150 g / L - 190 g / L, the solid-liquid ratio of the adsorption resin after adsorbing impurities to the hydrochloric acid solution is 1:0.5 - 0.8, and the desorption process conditions are: the desorption temperature is 60°C - 70°C, and the desorption time is 4 h - 6 h.

[0013] According to the above-mentioned method for removing impurities from the electrowinning cobalt circulating solution, it is characterized in that in step (3), the solid-liquid ratio of the desorbed resin to the liquid caustic soda is 1:0.5 - 1, and the process conditions for transforming the desorbed resin with the liquid caustic soda are: the liquid caustic soda passes through the desorbed resin at a speed of 0.5 BV / h, the reaction temperature is 30°C - 40°C, the reaction time is 1 h - 2 h, and the reaction pressure is 0.1 MPa - 0.11 MPa.

[0014] The beneficial technical effects of the present invention: The present invention uses Duolite CH-90Na resin to adsorb and remove impurities from the electrowinning cobalt circulating solution, and can reduce Cu and Zn in the circulating solution of electrowinning cobalt to less than 0.001 g / L, meeting the production requirements. After the resin is saturated in adsorption, hydrochloric acid is used to regenerate the resin, and finally liquid caustic soda is used to transform the resin. After the transformation is completed, it can be reused. Description of the Drawings

[0015] Figure 1 It is a process flow schematic diagram of the present invention. Detailed Embodiments

[0016] See Figure 1 , a method for removing impurities from an electrowinning cobalt circulating solution of the present invention includes the following steps:

[0017] (1) Adsorb the electrowinning cobalt circulating solution with an adsorption resin at an adsorption temperature of 40°C - 50°C to obtain the electrowinning cobalt circulating solution with reduced copper and zinc and the adsorption resin after adsorbing impurities; the liquid-solid ratio of the electrowinning cobalt circulating solution (L) to the adsorption resin (kg) is 20 - 30:1; the adsorption resin is Duolite CH-90Na resin. The copper content in the electrowinning cobalt circulating solution after reducing copper and zinc is less than 0.001 g / L, and the zinc content is less than 0.001 g / L.

[0018] (2) Desorb the adsorption resin after adsorbing impurities to obtain the desorbed resin and a solution containing copper and zinc; desorb the adsorption resin after adsorbing impurities with a hydrochloric acid solution, the concentration of the hydrochloric acid solution is 150 g / L - 190 g / L, and the solid-liquid ratio of the adsorption resin after adsorbing impurities (kg) to the hydrochloric acid solution (L) is 1:0.5 - 0.8. The desorption process conditions are: the desorption temperature is 60°C - 70°C, and the desorption time is 4 h - 6 h.

[0019] (3) Transform the desorbed resin with liquid caustic soda to obtain the regenerated adsorption resin and a solution containing sodium ions, and the regenerated adsorption resin is returned to step (1) for repeated use. The solid-liquid ratio of the desorbed resin (kg) to the liquid caustic soda (L) is 1:0.5 - 1. The process conditions for transforming the desorbed resin with liquid caustic soda are: pass the liquid caustic soda through the desorbed resin at a rate of 0.5 BV / h, the reaction temperature is 30°C - 40°C, the reaction time is 1 h - 2 h, and the reaction pressure is 0.1 MPa - 0.11 MPa.

[0020] The technical solution of the present invention will be further explained and illustrated through the following examples.

[0021] Example 1

[0022] Adsorb the electrowinning cobalt circulating solution with Duolite CH-90Na resin at an adsorption temperature of 40°C to obtain the electrowinning cobalt circulating solution with reduced copper and zinc and the adsorption resin after adsorbing impurities; the liquid-solid ratio of the electrowinning cobalt circulating solution (L) to the adsorption resin (kg) is 20:1. The copper content in the electrowinning cobalt circulating solution with reduced copper and zinc is less than 0.0005 g / L, and the zinc content is less than 0.0005 g / L.

[0023] Desorb the adsorption resin after adsorbing impurities to obtain the desorbed resin and a solution containing copper and zinc; desorb the adsorption resin after adsorbing impurities with a hydrochloric acid solution, the concentration of the hydrochloric acid solution is 150 g / L, and the solid-liquid ratio of the adsorption resin after adsorbing impurities (kg) to the hydrochloric acid solution (L) is 1:0.5. The desorption process conditions are: the desorption temperature is 60°C, and the desorption time is 4 h.

[0024] Transform the desorbed resin with liquid caustic soda to obtain the regenerated adsorption resin and a solution containing sodium ions, and the regenerated adsorption resin is returned to the first step for repeated use to adsorb impurities in the electrowinning cobalt circulating solution. The solid-liquid ratio of the desorbed resin (kg) to the liquid caustic soda (L) is 1:0.5. The process conditions for transforming the desorbed resin with liquid caustic soda are: pass the liquid caustic soda through the desorbed resin at a rate of 0.5 BV / h, the reaction temperature is 30°C, the reaction time is 1 h, and the reaction pressure is 0.1 MPa.

[0025] Example 2

[0026] The electrowinning cobalt circulating solution is adsorbed using Duolite CH-90Na resin at an adsorption temperature of 45°C to obtain an electrowinning cobalt circulating solution with reduced copper and zinc and an adsorption resin after adsorbing impurities; the liquid-solid ratio of the electrowinning cobalt circulating solution (L) to the adsorption resin (kg) is 25:1. The copper content in the electrowinning cobalt circulating solution with reduced copper and zinc is less than 0.0005 g / L, and the zinc content is less than 0.0005 g / L.

[0027] The adsorption resin after adsorbing impurities is desorbed to obtain a desorbed resin and a solution containing copper and zinc; the adsorption resin after adsorbing impurities is desorbed using a hydrochloric acid solution with a concentration of 170 g / L. The solid-liquid ratio of the adsorption resin after adsorbing impurities (kg) to the hydrochloric acid solution (L) is 1:0.65, and the desorption process conditions are: desorption temperature is 65°C, and desorption time is 5 h.

[0028] The desorbed resin is transformed using liquid caustic soda to obtain a regenerated adsorption resin and a solution containing sodium ions. The regenerated adsorption resin is returned to the first step for repeated use to adsorb impurities in the electrowinning cobalt circulating solution. The solid-liquid ratio of the desorbed resin (kg) to the liquid caustic soda (L) is 1:0.75. The process conditions for transforming the desorbed resin using liquid caustic soda are: the liquid caustic soda passes through the desorbed resin at a rate of 0.5 BV / h, the reaction temperature is 35°C, the reaction time is 1.5 h, and the reaction pressure is 0.105 MPa.

[0029] Example 3

[0030] The electrowinning cobalt circulating solution is adsorbed using Duolite CH-90Na resin at an adsorption temperature of 50°C to obtain an electrowinning cobalt circulating solution with reduced copper and zinc and an adsorption resin after adsorbing impurities; the liquid-solid ratio of the electrowinning cobalt circulating solution (L) to the adsorption resin (kg) is 30:1. The copper content in the electrowinning cobalt circulating solution with reduced copper and zinc is less than 0.0005 g / L, and the zinc content is less than 0.0005 g / L.

[0031] The adsorption resin after adsorbing impurities is desorbed to obtain a desorbed resin and a solution containing copper and zinc; the adsorption resin after adsorbing impurities is desorbed using a hydrochloric acid solution with a concentration of 190 g / L. The solid-liquid ratio of the adsorption resin after adsorbing impurities (kg) to the hydrochloric acid solution (L) is 1:0.8, and the desorption process conditions are: desorption temperature is 70°C, and desorption time is 6 h.

[0032] The resin after desorption is transformed with liquid caustic soda to obtain the regenerated adsorption resin and a solution containing sodium ions. The regenerated adsorption resin is returned to the first step for reuse to adsorb impurities in the electrowinning cobalt circulating solution. The solid-liquid ratio of the resin after desorption (kg) to liquid caustic soda (L) is 1:1. The process conditions for transforming the resin after desorption with liquid caustic soda are as follows: the liquid caustic soda passes through the resin after desorption at a rate of 0.5 BV / h, the reaction temperature is 40 °C, the reaction time is 2 h, and the reaction pressure is 0.11 MPa.

Claims

1. A method for removing impurities from the electrowinning cobalt circulating solution, characterized in that, The method comprises the following steps: (1) Adsorbing the electrowinning cobalt circulating liquid with an adsorption resin to obtain an electrowinning cobalt circulating liquid with reduced copper and zinc and an adsorption resin after adsorbing impurities; the copper content in the electrowinning cobalt circulating liquid with reduced copper and zinc is less than 0.0005 g / L, the zinc content is less than 0.0005 g / L, and the liquid-solid ratio of the electrowinning cobalt circulating liquid to the adsorption resin is 20 - 30:1; (2) Desorbing the adsorption resin after adsorbing impurities with a hydrochloric acid solution, the concentration of the hydrochloric acid solution is 150 g / L - 190 g / L, the solid-liquid ratio of the adsorption resin after adsorbing impurities to the hydrochloric acid solution is 1:0.5 - 0.8, and the desorption process conditions are: the desorption temperature is 60°C - 70°C, the desorption time is 4 h - 6 h, to obtain a desorbed resin and a solution containing copper and zinc; (3) Transforming the desorbed resin with liquid caustic soda, the solid-liquid ratio of the desorbed resin to the liquid caustic soda is 1:0.5 - 0.75, and the process conditions for transforming the desorbed resin with liquid caustic soda are: passing the liquid caustic soda through the desorbed resin at a speed of 0.5 BV / h, the reaction temperature is 30°C - 40°C, the reaction time is 1 h - 2 h, the reaction pressure is 0.1 MPa - 0.11 MPa, to obtain a regenerated adsorption resin and a solution containing sodium ions, and the regenerated adsorption resin is returned to step (1) for repeated use.

2. The method for removing impurities from the electrowinning cobalt circulating solution according to claim 1, characterized in that, In step (1), the adsorption resin is Duolite CH-90Na resin.

3. The method for removing impurities from the electrowinning cobalt circulating solution according to claim 1, characterized in that, In step (1), the adsorption temperature for adsorbing the electrowinning cobalt circulating liquid with the adsorption resin is 40°C - 50°C.

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