Evaluation of Borax as an Alternative to Mercury in Gold Recovery: A Case Study of Benishangul Gumuz Region, Assosa Area, Western Ethiopia
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Date
2025-05
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Addis Ababa University
Abstract
Artisanal and small-scale gold mining (ASGM) plays a critical role in the Ethiopian economy, particularly in rural and resource-endowed regions like the Benishangul Gumuz Region, where it forms a mainstay of livelihood for many households. However, the extensive use of mercury for gold recovery in ASGM operations has raised serious environmental and public health concerns, such as soil and water contamination and toxic exposure that affect not only miners but also adjoining communities. The goal of this study was to evaluate borax as a safer and more environmentally friendly alternative to mercury in the gold extraction process, with a focus on the Assosa Zone. The study adopted comparative experimental analysis with ore samples collected from two geologically different mining areas: Agosha Kebele (quartz-vein-hosted primary ores) and Mukufute Kebele (alluvial placer deposits). Through the adoption of borax smelting and conventional mercury amalgamation techniques, the effectiveness of gold recovery was analyzed using statistical methods, including descriptive analysis, Wilcoxon Signed-Rank tests, and ANOVA. The results revealed that borax smelting yielded significantly better gold yields, with a mean recovery of 0.6125 g, compared to 0.2345 g from mercury amalgamation, while at the same time avoiding the toxic emissions and residual pollution associated with mercury. Borax also proved versatile for both ore types and showed practical advantages regarding safety, cost-effectiveness, and environmental preservation. This study confirms the technical and economic viability of introducing borax in Ethiopia’s ASGM industry and informs the wider effort towards reducing mercury use in small-scale mining. The study concludes by advocating for the adoption of borax through policy support, stakeholder training, and awareness creation, while also proposing areas of future research to determine its long-term environmental effects, socio-cultural acceptability, and potential for scalability in other mining areas.
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Borax, Mercury-Free Gold Recovery, Artisanal Mining