Method for deeply removing cadmium in high-concentration cobalt sulfate solution and recovering cadmium

Abstract

The invention discloses a method for deeply removing cadmium in a high-concentration cobalt sulfate solution and recovering the cadmium. According to the method, firstly, an extracted organic phase containing Cyanex301 is adopted to enable the concentration of the cadmium to be decreased to be 0.001 g/L or less; cobalt and the cadmium in the organic phase are reversely extracted through sulfuric acid and hydrochloric acid, then resin is used for adsorbing metal complexing ions in stripping liquor, so that the cyclic utilization of the stripping liquor is realized; the resin is desorbed by using distilled water, so that separation of the cobalt and the cadmium on the resin is realized; and a desorption solution of the cadmium is subjected to vulcanization treatment, the cadmium is recycledin a form of a CdS product, and finally the ammonia desorption solution is returned for cadmium desorption, and the loss rate of the cobalt is almost zero in the whole technological process. The method has the advantages of being capable of efficiently removing the cadmium and cleaning and recovering the cadmium and capable of being widely applied to industrial production.

Description

technical field [0001] The invention belongs to the technical field of impurity separation and recovery, and in particular relates to a method for deeply removing and recovering septum from a high-concentration cobalt sulfate solution. Background technique [0002] At present, in industry, cobalt sulfate products are mainly used in the field of batteries. In order to meet the needs of battery materials, the concentration of cadmium in cobalt sulfate solution is ≤0.001g / L, so deep cadmium removal is the key to produce qualified cobalt sulfate products, but due to the similar chemical properties of cobalt and cadmium, the process of cadmium removal is complicated , and it is difficult to achieve deep separation of cobalt and cadmium. [0003] Traditional methods for removing cadmium from cobalt-nickel solutions containing cadmium usually include sulfide removal of cadmium, replacement of cadmium removal and hydrolysis of cadmium removal. The disadvantages of these methods ar...

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Problems solved by technology

But this method is only suitable in the chloride salt system, if in the sulfuric acid system, because most of complexed anions with cadmium will all be complexed with cobalt, the impurity removal cost becomes high (for example: iodized salt), and will cause Introduce other impurity ions and cause loss of main metal elements at the same time

[0007] Master thesis "Research on the Extraction and Separation of Cadmium from Cadmium, Cobalt, Nickel and Other Polymetallic Ions" discloses the extraction and separation of cadmium by Cyanex301. When the pH is less than 0.3, it means that in this pH range, for low concentration cobalt and nickel solutions, (Cd 2.25g / L, Co 1.18g / L, Ni 1.17g / L), reduce the extraction rate of cobalt or nickel, and the extraction rate of cadmium by Cyanex301 can reach 100%, but when the pH>0.3, the extraction of cobalt and nickel rate rise

It needs to control the solution in a small range of low pH, and is only suitable for processing low-concentration cobalt-containing solutions, which cannot be applied in industry

[0008] For the deep removal of cadmium in the industry at present, the conventional method generally adopts P204 multi-stage extraction to remove cadmium, but the raffinate after multi-stage countercurrent extraction is difficult to reach below 1mg / L, and there will be a large amount of cobalt in the process of cadmium removal. loss, increase the workload of recycling

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