Abstract
Background.The amalgamation method used by artisanal small-scale miners is the single largest source of global mercury emission. The goal of the ‘Free Your Mine’ project is to stop mercury use in artisanal and small-scale mining.Objectives.The aim of the present study was to compare gold recovery and time consumption between the amalgamation method and direct smelting, using borax for smelting under standardized conditions.Materials and Methods.This was an experimental study in a pragmatic setting in the mining community of Tiira, Uganda. Standardized amounts of gold ore of equal quality were processed with the local amalgamation method and with the Philippine mercury-free method as practiced by miners from Benguet in the Philippines, and the gold yield and time consumption were compared.Results.The amalgamation method took 53 minutes and recovered 1.0 g of pure gold. The miners used 4 g of mercury in the processing. The Philippine mercury-free method took 62 minutes and recovered 1.4 g of pure gold.Conclusions.The Philippine mercury-free method recovered 40% more gold than the amalgamation method but took 9 minutes longer. The Philippine mercury-free method is a viable alternative to amalgamation.Competing Interests.The authors declare no competing financial interests.
Highlights
Artisanal and small-scale mining (ASGM) is the exploration, extraction and processing of metals deposits, precious stones and industrial minerals with predominantly simple, but high labor-intensive technologies
Our experimental study in Tiira showed that direct smelting recovered
The comparison was carried out in a setting that was familiar for the local miners using the amalgamation method, which may have biased the results in favor of the amalgamation method
Summary
Artisanal and small-scale mining (ASGM) is the exploration, extraction and processing of metals deposits, precious stones and industrial minerals with predominantly simple, but high labor-intensive technologies. The amalgamation method used by artisanal small-scale miners is the single largest source of global mercury emission. The amalgamation method took 53 minutes and recovered 1.0 g of pure gold. The Philippine mercury-free method took 62 minutes and recovered 1.4 g of pure gold. The Philippine mercury-free method recovered 40% more gold than the amalgamation method but took 9 minutes longer. J Health Pollution 24: (191205) 2019 © Pure Earth environmental disaster and related health hazards, mercury-free methods must be implemented in ASGM communities worldwide. Towards this goal, most counties have signed the Minamata convention that aims to reduce global mercury pollution. Direct smelting has proven to be safe and implementable in various ASGM communities.[3,4,5,6,7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
