Ion exchange column desorption process for cobalt electrodeposition production of chlorination system

Abstract

The invention discloses an ion exchange column desorption process for cobalt electrodeposition production of a chlorination system, belongs to the field of hydrometallurgy, and solves the problems of high reagent consumption and high wastewater generation in the existing desorption process. The method comprises the following steps: after resin in an ion exchange column is saturated, emptying a cobalt chloride solution in the column; four-section countercurrent soaking and washing are adopted, cobalt adsorbed by ion exchange resin is resolved, a fourth-section soaking and washing solution medium is fresh water and is reused for third-section soaking and washing, the third-section soaking and washing solution is reused for second-section soaking and washing, the second-section soaking and washing solution is reused for first-section soaking and washing, and a cobalt chloride solution obtained after first-section soaking and washing serves as a production raw material for re-production; soaking the washed ion exchange resin in a hydrochloric acid solution for analysis; and washing with new water. According to the method, four-section countercurrent soaking and washing are adopted, the soaking and washing liquid obtained after each section of soaking and washing is recycled, the cobalt in the wastewater is enriched and prepared into the cobalt chloride solution, the cobalt chloride solution can serve as a raw material to be directly put into the cobalt chloride-electrodeposition production procedure, and the direct recovery rate of cobalt is increased.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgy, specifically relating to an ion exchange column analysis process for the electrowinning of cobalt in a chloride system. Background Technology

[0002] Electrolytic cobalt is one of the important raw materials for manufacturing high-temperature alloys, cemented carbides, and magnetic alloys. Currently, there are two main systems for preparing electrolytic cobalt: the chloride system and the sulfuric acid system. The chloride system is often used in the high-end market due to its low viscosity, high conductivity, fine grains, high density, and bright, smooth surface.

[0003] The cobalt chloride solution undergoes deep purification to remove impurities, and is then mixed with the catholyte and dechlorinated anolyte before electrowinning. The anolyte and chlorine gas are separated under negative pressure, and the anolyte is recycled after dechlorination and evaporation. The chlorine gas produced at the anode enters the chlorine recycling process. The cobalt chloride solution contains impurities such as As, Pb, Cd, and Cu. These impurity ions have relatively positive potentials and are easily deposited on the plate surface. Ion exchange is typically used to remove impurities, control the concentration of impurity metal ions, and increase the cobalt to impurity metal ion concentration ratio to inhibit impurity metal ion deposition. After the ion exchange column becomes saturated, it requires extensive regeneration using acid and alkali reagents. Hydrochloric acid is first used to remove the main metal and impurity metal ions. The eluent has high acidity and metal ion concentration, and can only be reused in the raw material slurry process, resulting in a long process and a large amount of wastewater. In actual production, the wastewater treatment slows down the washing rate of the ion exchange column, hindering production. Summary of the Invention

[0004] The purpose of this invention is to provide an ion exchange column desorption process for the production of cobalt by electrowinning in a chloride system, in order to solve the problems of high reagent consumption and high wastewater generation in existing desorption processes.

[0005] The technical solution of this invention is: an ion exchange column desorption process for the electrowinning of cobalt in a chloride system, comprising the following steps: A. After the resin in the ion exchange column is saturated, the cobalt chloride solution in the column is drained into the cobalt solution tank. B. A four-stage countercurrent rinsing process is adopted to desorb the cobalt adsorbed by the ion exchange resin (i.e., wash it). The fourth-stage rinsing solution is fresh water, which is reused in the third-stage rinsing. The third-stage rinsing solution is reused in the second-stage rinsing. The second-stage rinsing solution is reused in the first-stage rinsing. After the first-stage rinsing, a cobalt chloride solution is obtained and discharged into the cobalt solution tank. The solution in the cobalt solution tank is used as a production raw material for reprocessing. C. The ion exchange resin after soaking and washing in step B is leached and analyzed with hydrochloric acid solution. The eluent is then acidified and sent to process P507. D. Wash with fresh water; the analysis is complete at pH 4-5.

[0006] As a further improvement of the present invention, the resin in the ion exchange column includes one or more of D201, D751, and D363.

[0007] As a further improvement of the present invention, in step B, the soaking time for each section is 0.5-2 hours.

[0008] As a further improvement of the present invention, in step C, the concentration of hydrochloric acid solution is 1-3 mol / L.

[0009] As a further improvement of the present invention, in step C, the hydrochloric acid soaking time is 4-8 hours.

[0010] The beneficial effects of this invention are: 1. This invention optimizes the ion exchange column desorption process by using a four-stage countercurrent rinsing process. The rinsing solution after each stage is reused in the previous stage to enrich cobalt in the wastewater and prepare a cobalt chloride solution, which can be used as a raw material and directly fed into the cobalt chloride-electrowinning process to improve the direct recovery rate of cobalt.

[0011] 2. In this invention, the main metal ions cobalt attached to the resin are pre-cleaned by four-stage countercurrent soaking and washing, and then hydrochloric acid soaking and desorption are performed to reduce the cobalt concentration in the hydrochloric acid desorption solution. The subsequent hydrochloric acid desorption solution can be reused to extract P507 washing acid, reducing hydrochloric acid consumption, reducing wastewater treatment volume, and effectively saving chemical reagents. Detailed Implementation

[0012] The present invention will be further described in detail below with reference to specific embodiments.

[0013] Example 1 The resin used in the ion exchange column in this embodiment is D201.

[0014] A. After the resin in the ion exchange column is saturated, the cobalt chloride solution in the column is drained into the cobalt solution tank.

[0015] B. A four-stage countercurrent rinsing process is used to desorb (i.e., wash away) the cobalt adsorbed by the ion exchange resin. The fourth stage rinsing time is 1.5 hours, and the rinsing solution is fresh water, which is reused in the third stage rinsing. The third stage rinsing time is 1.5 hours, and the rinsing solution is reused in the second stage rinsing. The second stage rinsing time is 1.5 hours, and the rinsing solution is reused in the first stage rinsing. The first stage rinsing time is 1.5 hours. After the first stage rinsing, a cobalt chloride solution is obtained and discharged into the cobalt liquid tank. The solution in the cobalt liquid tank is used as raw material for production.

[0016] C. The ion exchange resin washed in step B is soaked in 2 mol / L hydrochloric acid solution for 6 hours for elution. The elution solution is then prepared into 1.2 mol / L hydrochloric acid solution and sent to process P507.

[0017] D. Wash with fresh water; the analysis is complete at pH 4-5.

[0018] According to the analysis results, the cobalt content in the cobalt liquid tank was 65.4 g / L and the cadmium content was 0.0003 g / L; the cobalt content in the obtained hydrochloric acid eluent was 1.13 g / L and the cadmium content was 0.0001 g / L.

[0019] The above experimental results show that the D201 ion exchange resin can be efficiently desorbed through a four-stage countercurrent rinsing process.

[0020] Example 2 The resin used in the ion exchange column in this embodiment is D751.

[0021] A. After the resin in the ion exchange column is saturated, the cobalt chloride solution in the column is drained into the cobalt solution tank.

[0022] B. A four-stage countercurrent rinsing process is used to desorb (i.e., wash away) the cobalt adsorbed by the ion exchange resin. The fourth stage rinsing time is 2 hours, and the rinsing solution is fresh water, which is reused in the third stage rinsing. The third stage rinsing time is 2 hours, and the rinsing solution is reused in the second stage rinsing. The second stage rinsing time is 2 hours, and the rinsing solution is reused in the first stage rinsing. The first stage rinsing time is 2 hours, and the resulting cobalt chloride solution is discharged into the cobalt liquid tank. The solution in the cobalt liquid tank is then used as raw material for production.

[0023] C. The ion exchange resin washed in step B is soaked and eluted in 3 mol / L hydrochloric acid solution for 4 hours. The elution solution is then prepared into 1.2 mol / L hydrochloric acid solution and sent to process P507.

[0024] D. Wash with fresh water; the analysis is complete at pH 4-5.

[0025] According to the analysis results, the cobalt content in the cobalt liquid tank solution was 68.1 g / L and the copper content was 0.0005 g / L; the cobalt content in the obtained hydrochloric acid eluent was 0.98 g / L and the copper content was 0.0002 g / L.

[0026] The above experimental results show that the D751 ion exchange resin can be efficiently desorbed through a four-stage countercurrent rinsing process.

[0027] Example 3 The resin used in the ion exchange column in this embodiment is D363.

[0028] A. After the resin in the ion exchange column is saturated, the cobalt chloride solution in the column is drained into the cobalt solution tank.

[0029] B. A four-stage countercurrent rinsing process is used to desorb (i.e., wash away) the cobalt adsorbed by the ion exchange resin. The fourth stage rinsing time is 0.5 hours, and the rinsing solution is fresh water, which is reused in the third stage rinsing. The third stage rinsing time is 0.5 hours, and the rinsing solution is reused in the second stage rinsing. The second stage rinsing time is 0.5 hours, and the rinsing solution is reused in the first stage rinsing. The first stage rinsing time is 0.5 hours. After the first stage rinsing, a cobalt chloride solution is obtained and discharged into the cobalt liquid tank. The solution in the cobalt liquid tank is used as raw material for production.

[0030] C. The ion exchange resin washed in step B is soaked in 1 mol / L hydrochloric acid solution for 8 hours for elution. The elution solution is then prepared into 1.2 mol / L hydrochloric acid solution and sent to process P507.

[0031] D. Wash with fresh water; the analysis is complete at pH 4-5.

[0032] According to the analysis results, the cobalt content in the cobalt liquid tank solution was 60.6 g / L and the lead content was 0.00015 g / L; the cobalt content in the obtained hydrochloric acid eluent was 0.78 g / L and the lead content was 0.0001 g / L.

[0033] The above experimental results show that the D363 ion exchange resin can be efficiently desorbed through a four-stage countercurrent rinsing process.

Claims

1. An ion exchange column desorption process for cobalt electrowinning in a chloride system, characterized in that: Includes the following steps: A. After the resin in the ion exchange column is saturated, the cobalt chloride solution in the column is drained. B. A four-stage countercurrent rinsing process is adopted to desorb the cobalt adsorbed by the ion exchange resin. The rinsing solution in the fourth stage is fresh water, which is reused in the third stage rinsing. The rinsing solution in the third stage is reused in the second stage rinsing. The rinsing solution in the second stage is reused in the first stage rinsing. The cobalt chloride solution obtained after the first stage rinsing is used as a raw material for production. C. The ion exchange resin after step B is soaked and analyzed with hydrochloric acid solution. D. Wash with fresh water; the analysis is complete at pH 4-5.

2. The ion exchange column desorption process for cobalt electrowinning in a chloride system according to claim 1, characterized in that: The resin in the ion exchange column includes one or more of D201, D751, and D363.

3. The ion exchange column desorption process for cobalt electrowinning production in a chloride system according to claim 1 or 2, characterized in that: In step B, the soaking time for each section is 0.5-2 hours.

4. The ion exchange column desorption process for cobalt electrowinning production in a chloride system according to claim 1 or 2, characterized in that: In step C, the concentration of the hydrochloric acid solution is 1-3 mol / L.

5. The ion exchange column desorption process for cobalt electrowinning in a chloride system according to claim 4, characterized in that: In step C, the hydrochloric acid soaking time is 4-8 hours.