Sodium cyanide Leaching of Gold from Low - Grade Gold - Bearing Tailings

In the field of gold mining and extraction, the efficient recovery of gold from low - grade ores and tailings has become an increasingly important research topic. As high - grade gold deposits are gradually depleted, the exploitation of low - grade resources has attracted more and more attention. This article focuses on the Cyanide leaching process of gold from low - grade gold - bearing tailings, aiming to provide valuable insights into this area.

1. Introduction

Low - grade gold - bearing tailings, which are the residues after the primary processing of gold ores, still contain a certain amount of gold. Due to their complex mineralogical compositions and low gold grades, the extraction of gold from these tailings is challenging. However, with the continuous improvement of extraction technology, it is possible to economically recover gold from them. Cyanide leaching has long been a widely used method in the gold mining industry for its relatively high efficiency and selectivity in gold extraction.

2. Experimental Methods

2.1 Sample Preparation

The gold mine tailings used in this experiment were first subjected to a granulation process. Granulation is an important pretreatment step as it can improve the contact between the tailings particles and the leaching agent, thereby enhancing the leaching efficiency. After granulation, the tailings were ready for the subsequent Cyanide leaching test.

2.2 Pretreatment

The gold mine tailings were pretreated with an alkaline solution for 8 hours. This pretreatment step is crucial as it can help to break down some of the minerals in the tailings, making the gold more accessible to the cyanide leaching agent. It also adjusts the pH environment of the tailings, which is beneficial for the subsequent cyanide leaching reaction.

2.3 Cyanide Leaching

Cyanide leaching was carried out using Sodium cyanide as the leaching agent. The amount of Sodium Cyanide used was 1 kg/t. The leaching time was set at 24 hours, and during the leaching process, the pH of the solution was maintained within the range of 10.0 - 12.0. The appropriate pH value is necessary to ensure the stability of the cyanide ion and the effectiveness of the leaching reaction.

3. Experimental Results

The experimental results showed that under the above - mentioned conditions, the gold leaching rate could reach more than 60%. This indicates that the combined process of alkaline pretreatment and cyanide leaching is effective for extracting gold from this particular gold mine tailings. The 8 - hour alkaline pretreatment, 1 kg/t of sodium cyanide dosage, 24 - hour leaching time, and a pH range of 10.0 - 12.0 provided an optimized set of parameters for this leaching process.

4. Significance and Future Outlook

The successful application of this cyanide leaching method for low - grade gold - bearing tailings has significant implications. Firstly, it provides a practical way to recycle gold from tailings, reducing waste and increasing resource utilization. Secondly, it can potentially bring economic benefits to mining companies by recovering valuable gold from previously discarded tailings.

In the future, further research could be carried out to optimize this process. For example, exploring different types of pretreatments to improve the gold liberation rate, or studying the use of alternative leaching agents to reduce the environmental impact of cyanide. Additionally, the application of this technology to different types of low - grade gold - bearing tailings needs to be investigated to determine its universality.

In conclusion, the cyanide leaching process studied here offers a promising solution for the extraction of gold from low - grade gold - bearing tailings, and continuous research and improvement in this area will contribute to the sustainable development of the gold mining industry.