The secret to reprocessing copper mine tailings

With the continuous increase in the mining volume of copper resources, copper emissions are increasing day by day, and copper tailings have become a valuable resource that can be utilized. Since it contains a large amount of recyclable metal ores and non-metallic useful components, choosing a suitable reprocessing process to recover them is of great significance to the comprehensive utilization of copper tailings resources.

Today Xinhai Mining will show you the secret of re-selecting copper mine tailings. There are two common beneficiation methods for copper mine tailings: sulfide flotation and leaching.

Sulfide flotation method

The essence of the sulfide flotation method is to sulfide the finely ground copper oxide slurry with sulfide, and then add a xanthate collector for flotation. Copper oxide minerals are in sodium sulfide solution, adsorbing HS- and S2- ions, forming a covering layer of copper sulfide on the surface of the mineral. The adsorption of xanthate on the surface of sulfated copper oxide is just like on the surface of copper sulfide minerals. The adsorption is the same.

However, 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 sulfide flotation, it will not only affect the yield, but also waste a lot of chemicals. Therefore, before using the sulfide flotation method to treat copper tailings, it is necessary to pre-concentrate the raw tailings to remove a large amount of gangue minerals in advance, reduce the subsequent processing volume, avoid the waste of chemicals, and improve the incoming flotation grade.

Copper tailings leaching method

The leaching method is to convert the copper compound in the solid phase into copper ions in the liquid phase, and then extract the metallic copper in the leach solution. According to the different leaching agents, it can be divided into acid leaching, ammonia leaching, bacterial leaching and electrochemical leaching. Below, two common methods are mainly introduced: acid leaching and ammonia leaching.

Acid leaching method: Generally, dilute sulfuric acid is used as the leaching agent, which is suitable for treating copper oxide ores mainly composed of acidic gangue. This method has the advantages of high copper leaching rate, low price of leaching agent, and simple process and operation. However, its application range is relatively narrow, it is only suitable for processing simple copper oxide ores, and it requires low calcium, magnesium and impurity iron contents, and its leaching selectivity is relatively poor.

Ammonia leaching method: The ammonia leaching method can directly treat copper tailings, or the tailings can be reduced and roasted before being leached with ammonia. The ammonia leaching method is suitable for treating copper oxide ores with higher alkaline gangue content and more silt. The ammonia leaching method has relatively high selectivity for metallic copper and alkaline gangue components, and there are fewer impurity metal ions in the leach solution. However, this method has high requirements on equipment and high energy consumption.

The significance of copper tailings reprocessing is not only to avoid resource waste, but also to achieve higher profits and meet the growing demand for copper. The above is what Xinhai tells you about the secret of re-selection of copper mine tailings. For more information about the beneficiation process and equipment of copper mines and tailings, please feel free to consult Xinhai Mining.