THERE are many mercury-free strategies and processes that can improve efficiency in gold recovery for small and artisanal miners that will greatly enhance the present economic mining landscape.

This is according to mining specialist Dr. Bruce Marshall during his presentation to miners at the University of Guyana (UG) on Monday evening. The event was held under the theme “A mercury-free solution for artisanal and small-scale gold mining in Guyana.”

Dr. Marshall told the gathering that included UG students, that a small miner’s strategic plan should focus on overcoming the present inherent business factors and modify or change these factors to reduce the risk and guarantee maximum recovery from a mining pit.

He said mercury-free techniques are safer for miners, their families and local communities. They may also help miners market their gold at higher prices. Noting that because of limited access to capital and technology, the small scale and artisanal miners use rudimentary and often dangerous techniques. Dr. Marshall said mercury amalgamation is a widespread technique used by miners to recover gold, but the technique is particularly dangerous as it releases mercury into the air, a dangerous inorganic compound which poses serious threats to the health of the miners and the environment.

He said mercury has the ability to bio-accumulate in living tissue, such as fishes, exposing the nearby population and particularly those dependent on downstream rivers. Some of the options for mercury free mining includes: using concentration methods, gravity concentration methods, sluicing, shaking tables, spiral concentrators, vortex concentrators, centrifuges and chemical leaching.

Dr. Marshall said about 20 per cent of the world’s gold is produced by the artisanal and small-scale gold mining sector. This sector is also responsible for the largest releases of mercury into the environment of any sector globally. A major source of air pollution from mercury, artisanal and small-scale gold mining releases approximately 400 metric tons of airborne elemental mercury each year.

As such, he told the gathering when mercury is brought into contact with gold particles in sediments or crushed ore, it forms “amalgam” – a soft mixture of roughly 50 per cent mercury and 50 per cent gold.

To recover gold from the amalgam, it is heated to evaporate the mercury, leaving the gold behind. Mercury is released into air, water, and soil in several of the steps of this process.
He explained that mercury vapors in the air around amalgam burning sites can be alarmingly high and almost always exceed the World Health Organisation’s (WHO) limit for public exposure of 1,000 Nano gram/cubic meter. This puts the health of workers at risk along with those persons in the communities surrounding the processing centers.

He advised that government make appropriate modifications to the technical measures to include in developing new mercury laws, policies or regulations.

Strong emphasis, he said should be placed on encouraging local-level governance and community based monitoring systems. Community stakeholder participation in the processes of policy development and field implementation are critically important.

Government, Dr. Marshall further advised, should provide ways to assist the artisanal and small-scale miners as well as educate them on environmental management. Technological assistance and capacity/education services should be provided in all areas where there is a high concentration of small-scale miners.

It was noted that Conservational International (CI) Guyana and the World Wildlife Fund (WWF) are preparing to introduce two major projects which will see the reduction of dependence on mercury.

CI Guyana in collaboration with the Global Environment Facility (GEF) will soon introduce the Eldorado Gold Project. The $1.2Billion (US$5.8Million) project will work with artisanal and small-scale miners in Regions Eight and Nine to explore mercury-free mining by 2025 along the supply chain from prospectors to producers.

On August 16, 2017, Guyana ratified the Minamata Convention on Mercury bringing it into force. The Minamata Convention is an international treaty designed to protect human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds. Mercury is used in the gold mining industry and can be a threat to human health and the environment.

Guyana was one of the first countries to sign on to the legally binding agreement and had done so with the full support of the mining sector, mainly members of the Guyana Gold and Diamond Miners Association (GGDMA) and the Guyana Women Miners’ Organisation (GWMO) following consultations.