Method for recovering gallium and indium elements from waste residue containing gallium and indium elements

Abstract

The invention relates to a method for recovering gallium and indium elements from waste residue containing the gallium and indium elements. The method includes the following steps that (1), the wasteresidue containing the gallium and indium elements and an acid lixiviant are mixed, activated leaching treatment is carried out, and waste liquor containing the gallium and indium elements is obtainedafter treatment; and (2) the acid lixiviant is added to the waste liquor containing the gallium and indium elements obtained in the step (1) to adjust the pH value to be less than or equal to 4, thenthe waste liquor containing the gallium and indium elements passes through an adsorption column, an indium-containing adsorption column and gallium-containing enrichment liquid are obtained, the indium-containing adsorption column is washed through an eluent to obtain indium-containing enrichment liquid, an alkaline precipitator is added into the indium-containing enrichment liquid to obtain indium hydroxide precipitates, and the gallium-containing enrichment liquid is electrolyzed to obtain elemental gallium. The method for recovering the gallium and indium elements from the waste residue containing the gallium and indium elements can adapt to a wider range of the pH change, the flow change and the temperature change, the separation efficiency and purity are high, and 96% or above of thegallium and indium elements can be separated from the waste residue.

Description

technical field [0001] The invention relates to the technical field of separation and purification, in particular to a method for recovering gallium and indium elements from waste residue containing gallium and indium elements. Background technique [0002] As products containing gallium and indium elements, such as LEDs, solar panels, TV screens, and integrated circuit boards, continue to accelerate, the amount of waste slag containing gallium and indium elements in my country is also increasing year by year. Heavy metal pollution has seriously affected the self-repair of the ecological environment. Waste slag containing gallium and indium elements contains a large amount of secondary resources. How to realize the harmlessness in the process of developing these secondary resources and reduce the environmental pollution caused by the treatment of these waste slags has become a major problem facing all countries in the future. problem. On the other hand, products containing ...

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Problems solved by technology

On the other hand, products containing gallium and indium elements generally also contain precious metal components such as copper, silver, and gold. If these products cannot be effectively recycled after being discarded, it will definitely cause a great waste of resources

Although the hazards of waste slag generated after the waste of products containing gallium and indium elements have not yet attracted enough attention, and there are not many related reports, however, the valuable metals in products containing gallium and indium elements can be recovered and effectively disposed of through appropriate methods. Its toxic and harmful components are of great significance to the development of circular economy and environmental protection

[0003] In the prior art, there are many studies on solving the technical problem of "efficiently recovering gallium and indium elements from waste materials containing various heteroelements", but no one has proposed a relatively perfect technical solution to solve this problem

The most common method is to use high-temperature roasting method, such as a method for recovering germanium, gallium, and indium from waste diodes disclosed in CN102951618B, by crushing waste diodes, separating the organic components, and oxidizing and roasting the remaining metal powder. The product is dissolved and filtered with acid, and zinc powder is added to the filtrate to replace germanium, gallium, and indium elemental substances. The elemental substances are roasted at 600-700°C, and chlorine gas is introduced at the same time for chlorination. According to the gas condensation temperature of the chloride metal elements Different from the separation of germanium, gallium and indium elements, this method consumes a lot of energy, and chlorine gas is needed in the preparation process, and the exhaust gas and dust are discharged into the environment, causing serious environmental pollution, which is not suitable for industrial production

Relatively speaking, it is better to separate metal ions by extraction, as disclosed in CN103199148B, a method for recovering gallium, indium, and germanium from waste thin-film solar cells, in which metal ions are dissolved in oxidative acid solution, and precipitated The pH value of the solution is used to separate the heteroelement ions, the gallium element is separated by electrolysis, and the indium ion is finally separated by organic system extraction and reverse extraction, and indium hydroxide is obtained by precipitation. This method does not produce dust and exhaust gas pollution, but the extraction The process still needs to use a large amount of water and extraction solution, and the extraction cannot obtain gallium and indium ions with higher purity.

Other methods, such as CN103620070B discloses a method for recovering indium elements. A solution containing indium ions is obtained by hydrothermal leaching, and bacteria for indium ion adsorption are added to the solution containing indium ions to obtain indium ions adsorbed inside the bacterial cells. , the method has higher adsorption efficiency of metal ions and higher separation purity, but the adsorption of bacteria is slower, the cost of bacterial culture and post-treatment is higher, and it is not suitable for large-scale production

The latest, such as CN104212983A discloses a method for reclaiming indium from waste displays, by dissolving waste liquid crystal displays with acid solution, adjusting the pH value to 1.5-2.5, filtering to remove filter residue, and the obtained filtrate is separated by phosphoramidate-based chelating resin The column selectively adsorbs indium ions, and the separation column elutes the solution containing indium ions through hydrochloric acid. However, in this method, the efficiency of dissolving indium ions using hydrochloric acid is low, and the use of phosphoramidate-based chelating resins and other ion-type separation columns separates indium ions. The separation efficiency is greatly affected by pH, and the separation efficiency can reach about 90% only when the pH is 1.5-2.5, so further improvement is needed

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