Copper Oxide Flotation Process: A Key Technology for Efficient Copper Resource Recovery

With the increasing scarcity of copper resources, the development and utilization of copper oxide ores have become an important issue in the mining field. Flotation, with its advantages of environmental friendliness, relatively low cost, and simple process, has become the mainstream method for processing copper oxide ores. Among them, direct flotation, sulfide flotation, segregation flotation, and beneficiation-metallurgy combined methods have their own characteristics, providing targeted solutions for different types of copper oxide ores.

As the earliest applied process, direct flotation separates target minerals directly using collectors without pre-treatment. Agents such as sodium oleate and tert-butyl salicylaldoxime have significant collecting effects on minerals with good floatability like malachite. Under alkaline conditions, the functional groups of the agents chemically adsorb with copper ions on the mineral surface, forming a hydrophobic film to achieve efficient separation. However, this method has high requirements for ores. The content of slime and calcium-magnesium carbonate minerals will affect the flotation effect, and it is difficult to deal with minerals with poor floatability such as chrysocolla.

Sulfide flotation pre-treats copper oxide ores with sulfiding agents to form a metal sulfide film on the mineral surface, enhancing the adsorption of collectors and improving hydrophobicity. Sodium sulfide and ammonium sulfate are commonly used sulfiding agents. Studies have shown that segmented reagent addition can avoid the inhibition of flotation caused by excessive sulfiding agents. Desliming treatment can reduce the adsorption of reagents by slime, significantly improving the separation indicators. At present, this method has become the most widely used process for copper oxide ore treatment in industrial production.

Although segregation flotation can recover valuable metals such as copper and silver, it is rarely used in practice due to high energy consumption and cost. The beneficiation-metallurgy combined method, by combining the advantages of metallurgy and flotation, has a significant effect on refractory ores with complex properties and low grades. For example, flotation-leaching combined method, ammonia leaching-sulfide precipitation-flotation method, etc., have effectively improved resource recovery rates.

Flotation reagents are the core of the process. The innovative application of collectors, activators, depressants, and frothers continues to promote the development of flotation technology. Conventional collectors such as butyl xanthate and hydroxamic acid exert synergistic effects through combined use. New collectors such as HPTT and BOPHPDT show good prospects due to their excellent selectivity and low pollution characteristics. Activators such as ammonium sulfate enhance sulfidation effects, and new activator HB-426 can replace traditional sodium sulfide. The application of depressant T506 and frother 730E has further optimized flotation indicators.

In the future, with the deepening of research on sulfide flotation mechanism, beneficiation-metallurgy combined method, and the development of new reagents, the copper oxide flotation process will move towards a more efficient, environmentally friendly, and economical direction, providing strong support for the sustainable utilization of copper.