Method for carrying out precipitate impurity removal on copper electrolyte

Abstract

The invention discloses a method for carrying out precipitate impurity removal on a copper electrolyte. The method comprises the following steps: adding an antimony compound in the copper electrolyte to remove co-precipitates containing arsenic, antimony and bismuth in the copper electrolyte as a precipitant, then directly returning the copper electrolyte to an electrolysis system after the impurity removal, and comprehensively recovering the precipitates containing arsenic, antimony and bismuth through a gradient temperature-control firing method. Low-temperature decomposition is carried out on the precipitates to obtain a low-temperature decomposition gas and low-temperature decomposition residues under inert gas shied, the low-temperature decomposition gas is condensed to obtain an arsenic compound, high-temperature decomposition is carried out on the low-temperature decomposition residues under atmosphere control to obtain a bismuth compound and a high-temperature decomposition gas, the high-temperature decomposition gas is condensed to obtain an antimony compound, and the antimony compound is returned to a precipitate impurity removal procedure for the copper electrolyte as the precipitant. According to the method disclosed by the invention, arsenic, antimony and bismuth in the copper electrolyte are independently recovered in the form of high-purity compounds while being efficiently removed; and the method has the characteristics of being short in flow, simple to operate, high in removal rate, free from the emission of 'three wastes', capable of repeatedly using the precipitant, low in cost and the like, and is suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to a method for purifying electrolyte in nonferrous metal hydrometallurgy process, in particular to a method for removing and comprehensively recovering arsenic, antimony and bismuth impurities in copper electrolyte. Background technique [0002] With the rapid development of the copper smelting industry, there are fewer and fewer high-quality copper concentrates, and the content of impurities such as arsenic, antimony, and bismuth in the anode copper of mines is on the rise, resulting in high content of arsenic, antimony, and bismuth in the copper electrolyte. Since the precipitation potential of arsenic, antimony, and bismuth is similar to that of copper, when the content of arsenic, antimony, and bismuth in the electrolyte reaches a certain concentration, it is easy to precipitate at the cathode together with copper. In addition, the arsenic, antimony, and Bismuth is easy to form "floating anode slime" to adhere to or be mech...

AI Technical Summary

Problems solved by technology

Since the precipitation potential of arsenic, antimony, and bismuth is similar to that of copper, when the content of arsenic, antimony, and bismuth in the electrolyte reaches a certain concentration, it is easy to precipitate at the cathode together with copper. In addition, the arsenic, antimony, and Bismuth is easy to form "floating anode slime" to adhere or mechanically entrap on cathode copper, thus affecting the quality of cathode copper

[0003] In order to ensure the normal progress of the copper electrolysis process, the current copper electrolysis industry often uses the induction method to purify the electrolyte to remove impurities such as arsenic, antimony, and bismuth in the electrolyte. However, for copper electrolytes with high antimony and high bismuth, the The process has low impurity removal efficiency, large net liquid volume, high cost, and produces toxic gas and causes great environmental pollution.

In recent years, scholars at home and abroad have been seeking new copper electrolyte purification processes, and have developed many effective methods for removing arsenic, antimony, and bismuth, including stannic acid and activated carbon adsorption purification, barium carbonate, strontium carbonate co-precipitation bismuth, Adsorption resin adsorption of antimony, bismuth, solvent extraction of arsenic, antimony, bismuth and other methods, but these methods have defects such as low impurity removal efficiency, large fixed investment, and certain side effects on the electrolyte to varying degrees

Patent applications 201410333413.1, 201510422489.6 and 201610775577.9 disclose methods for removing impurities by precipitation in copper electrolyte, using antimony or / and bismuth oxides and their hydrates as adsorbents or precipitants to remove arsenic, antimony and bismuth in the electrolyte , but the common point of these methods is to carry out alkali leaching to the obtained solid precipitate to regenerate the precipitant. Therefore, there are defects such as long process flow, acid-base alternation, and large reagent consumption. A variety of waste water will also be produced, which needs to be further recycled and treated

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