(1) Sulfide flotation of copper tailings

The flotation method is to refine pulp with sulfide sulfuration and flotation with a xanthate collector. In sodium sulfide solution, copper oxide adsorbs HS- and S2-. It forms a coating of copper sulfide. The adsorption of xanthate on the surface of copper sulfide oxides is similar to that of copper sulfide minerals.

In the actual production process, the amount of tailings is much greater than the amount of concentrate. If the copper tailings are directly recovered by sulfidation flotation, it will not only affect the yield but also waste a large number of chemical reagents. 

Therefore, before adopting sulfidation flotation to treat copper tailings, it is necessary to pre-enrich the original tailings, discard a large number of gangue minerals in advance, reduce the amount of follow-up treatment, avoid waste of chemicals, and improve the flotation grade.

In the post-treatment process of copper tailings, the high-grade copper concentrate can be obtained by sulfidation flotation. Has a very good restorative effect. However, sulfuration flotation technology requires high requirements and a large investment. Suitable for large copper tailings processing plants.

(2) Copper tailings leaching method

Copper tailings leaching is to convert solid copper compounds into copper ions in the liquid phase, and then extract metallic copper from the leaching solution. According to different leaching reagents, it can be divided into acid leaching, ammonia leaching, bacterial leaching, and electrochemical leaching. In the following article, two common methods will be introduced.

Acid leaching: Dilute sulfuric acid is generally used as a bleaching agent, which is suitable for the treatment of copper oxide ores mainly containing acidic gangue. The method has the advantages of a high copper leaching rate, low price of leaching agent, and simple process operation. However, its scope of application is narrow, and it is only suitable for treating simple copper oxide ores. The requirements for calcium, magnesium, and impurity iron content are low, and the leaching selectivity is poor.

Ammonia leaching: ammonia leaching can be directly used for copper tailings. Tailings can also be reduced and roasted before ammonia leaching. The ammonia leaching method is suitable for treating copper oxide ores with high alkaline gangue and silt content. The ammonia leaching method has high selectivity to copper and alkaline gangue components, and there are few impurity metal ions in the leaching solution. However, this method requires high equipment and consumes a lot of energy.

In addition, there are many other valuable elements in copper tailings. According to the composition of copper tailings, various useful components such as gold, iron, silver, wollastonite, fluorite, etc. can also be selected. In the reprocessing process of copper tailings, sulfidation flotation and leaching methods can be used to reprocess copper tailings. In the actual production process, it is necessary to select appropriate equipment according to the properties of copper tailings and recover copper from waste rocks and tailings, as well as various useful metal and non-metal elements, such as gold, silver, iron, etc. Realize efficient utilization of copper resources.