Oxygen Cyanidation Leaching of Copper - Bearing Gold Concentrates: Challenges and Solutions

Introduction

In the mining industry, processing copper - bearing gold concentrates is fraught with difficulties that compromise the economic sustainability of mines. Among these, the high consumption of cyanide and the relatively high gold content in tailings stand out as major hurdles. These issues not only impede the efficient extraction of gold but also reduce the overall profitability of mining operations.

The Problem of High Cyanide Consumption

Chemical Reactions Involving Copper Minerals

The high cyanide consumption in copper - bearing gold concentrates is primarily attributed to the chemical reactions between copper minerals and cyanide. Copper has a tendency to form various complexes with cyanide. During the leaching process, these reactions consume a large quantity of the cyanide reagent. Additionally, certain copper minerals can interfere with the dissolution of gold, causing the gold grade in tailings to rise. This not only leads to a waste of precious resources but also heightens the environmental risks associated with cyanide usage.

Research and Solutions

Experimental Studies

To tackle these problems, our research team carried out a comprehensive series of experimental investigations. Through systematic exploration of the oxygen cyanidation leaching process for copper - bearing gold concentrates, we were able to discern the general principles governing this complex chemical reaction system.

Process Optimization Measures

High - Concentration Sodium Cyanide Leaching

One of the key improvements proposed is the utilization of a high - concentration sodium cyanide leaching process. By increasing the concentration of sodium cyanide, the reaction rate between gold and cyanide can be accelerated, thereby promoting more efficient gold dissolution. Moreover, appropriate adjustment of the sodium cyanide concentration can better regulate the reaction between copper and cyanide, minimizing unnecessary cyanide consumption.

Pure Oxygen or Oxygen - Enriched Leaching

Another crucial measure is the adoption of pure oxygen or oxygen - enriched leaching. Oxygen acts as a vital oxidant in the cyanidation process. A pure oxygen or oxygen - enriched environment can significantly increase the oxidation potential of the leaching system. This facilitates the oxidation of gold and promotes its dissolution in the cyanide solution. Compared to traditional air - blown leaching methods, pure oxygen or oxygen - enriched leaching can effectively shorten the leaching time, enhance the leaching efficiency, and reduce the required amount of cyanide.

Results and Benefits

Reduction in Tailings Gold Grade and Cyanide Consumption

Through the implementation of these improved processes, remarkable outcomes have been achieved. The gold grade in cyanide tailings has been significantly decreased, signifying a higher gold recovery rate. Simultaneously, the unit cyanide consumption has dropped substantially. This not only cuts production costs but also alleviates the environmental impact of cyanide use.

Conclusion

In summary, our research on the oxygen cyanidation leaching of copper - bearing gold concentrates has provided valuable insights and practical solutions to long - standing industry problems. By optimizing the leaching process with high - concentration sodium cyanide and pure oxygen or oxygen - enriched leaching, we have successfully enhanced the economic and environmental performance of gold extraction from copper - bearing gold concentrates. We anticipate that these research findings will be widely adopted in the mining industry, contributing to more sustainable and efficient gold mining operations.