Eco-friendly Gold Leaching Reagent and Sodium Cyanide Synergistic Leaching of High-Grade Gold Ore

In the mining industry, the efficient extraction of gold from ores is of utmost importance. As environmental concerns grow, the development and application of environmentally friendly extraction methods have become a key focus. This article presents the results of a synergistic leaching experiment on high-grade gold ore using an environmentally friendly leaching agent and Sodium Cyanide.

Eco-friendly Gold Leaching Reagent

Sodium cyanide

Introduction

The gold mining industry has long relied on traditional cyanide leaching processes to extract gold from ores. However, cyanide is highly toxic and poses significant environmental and safety risks. Therefore, there is an urgent need to find alternative methods or develop technologies that can reduce the use of cyanide while maintaining high extraction efficiencies. The environmentally friendly gold leaching agent used in this study is a promising alternative, and its synergistic effect with sodium cyanide was investigated to determine the feasibility of applying this combination to high-grade gold ore.

Experimental Materials and Methods

Ore Characteristics

The ore used in this experiment had a gold grade of 12.24 g/t and a silver grade of 131.91 g/t. These relatively high grades make it an ideal candidate for evaluating the effectiveness of the synergistic leaching process.

Experimental Conditions

• Grinding fineness: ~74 μm accounted for 95%. This fine grinding is crucial as it increases the surface area of the ore particles, facilitating the leaching reaction.

• Environmentally friendly gold leaching agent dosage: 2 kg/t. The specific amount was determined through preliminary experiments to optimize the leaching effect.

• Sodium cyanide dosage: 1 kg/t. Reducing the cyanide dosage while maintaining good leaching performance is one of the main goals of this study.

• Lime dosage: 4 kg/t. Lime is added to adjust the pH of the pulp, which is essential for the stability and efficiency of the leaching process.

• Pulp concentration: 40%. This concentration provides an appropriate environment for the leaching reagents to react with the ore particles.

• Leaching time: 24 h. A sufficient leaching time is required to ensure that the gold and silver are fully extracted.

Experimental Results

Under the above - mentioned experimental conditions, the leaching rates of gold and silver were measured. The results showed that the leaching rate of gold could be stably maintained at 98.07%, and the leaching rate of silver reached 86.30%. These high leaching rates indicate that the synergistic leaching method using the environmentally friendly gold leaching agent and Sodium cyanide is highly effective for this high - grade gold ore.

Discussion

The high leaching rates obtained in this experiment can be attributed to the combined action of the environmentally friendly gold leaching agent and sodium cyanide. The environmentally friendly agent may enhance the reactivity of the ore surface, making it easier for cyanide to react with gold and silver. At the same time, the reduced dosage of sodium cyanide not only helps to reduce environmental risks but also lowers production costs to a certain extent. The adjustment of pH by lime also plays a positive role in promoting the leaching reaction.

Conclusion

This study demonstrates the feasibility of using a synergistic leaching method with an environmentally friendly gold leaching agent and sodium cyanide for high - grade gold ore. The high leaching rates of gold and silver achieved under optimized conditions show great potential for industrial application. This method not only improves the extraction efficiency but also reduces the environmental impact associated with traditional cyanide - only leaching processes. Further research can be carried out to optimize the process parameters further and expand the application scope to different types of gold ores.