Maelgwyn Mineral Services Africa process manager Wiehan Botes
The 2023 World Gold Conference, held in Shenyang, China, from September 4 to 7, offered a compelling platform for the mining industry to address critical issues surrounding cyanide management and environmentally responsible gold extraction. Among the remarkable contributions at the conference, one paper in particular, written by Maelgwyn Mineral Services Africa process manager Wiehan Botes and his team, stood out as a beacon of knowledge and innovation in the field.
The paper, titled A review of cyanide destruction processes from laboratory and plant evaluations, shone a spotlight on the pressing issue of cyanide destruction. Cyanide management and compliance within the International Cyanide Management Institute (ICMI) guidelines have become paramount for mining companies, especially in light of increasing Environmental, Social, and Governance (ESG) investments.
The conference itself was marked by a significant emphasis on ESG factors and reducing the carbon footprint associated with gold extraction processes, reflecting a growing global concern for sustainable mining practices. The discussions and papers presented during the event provided valuable insights into the evolving dynamics of the gold mining industry.
The Chinese presentations largely concentrated on pyrometallurgy, an interesting observation that underscored potential gaps in knowledge within the hydrometallurgy sector, while English papers delved into refining and optimising existing processes, highlighting the industry's commitment to enhancing efficiency and sustainability.
Cyanide destruction is essential for processing plants as they grapple with efficiently detoxifying slurry tailings and solution streams that may be released into the environment. In the Maelgwyn paper, Botes and his team conducted three laboratory and on-site cyanide destruction test campaigns, evaluating both solution and slurry streams, with a particular focus on two cyanide destruction processes - Sulphur Dioxide (INCO) and Hydrogen Peroxide.
Site A saw a continuous detoxification campaign conducted on a high-TDS (Total Dissolved Solids) solution stream in North Africa, using both INCO and Hydrogen Peroxide processes to assess detoxification efficiency.
Site B involved the evaluation of INCO and Hydrogen Peroxide processes on slurry and solution streams in Central Africa, comparing results to the actual solution detox performance at the plant. It also scrutinized the effectiveness of the INCO process on slurry versus solution streams.
Site C engaged in laboratory testwork in South Africa, focusing on the INCO detox process's implementation and the importance of oxygen addition through an efficient oxygen mass transfer device.
This comprehensive study provides critical insights into feed chemistry, reagent addition, process control philosophy, and the impact of stream type (solution or slurry) on cyanide destruction efficiency.
Cyanide detoxification is essential in reducing weak acid dissociable cyanide (CN WAD) levels, and the choice of the detoxification process plays a crucial role in ensuring environmentally responsible mining practices. Botes and his team's paper is expected to drive discussions and innovations in cyanide management, contributing to the industry's continuous efforts in promoting responsible and sustainable gold extraction practices.
The World Gold Conference 2023 also served as a valuable networking opportunity, facilitating meaningful interactions between industry professionals. This event, with its combination of knowledge sharing and networking, continues to be an essential milestone in advancing the collective wisdom of the gold mining sector, especially as it faces the challenges of the 21st century.