Mercury Free Mining: An Exquisite Opportunity to Make a Global Difference

Posted on April 14, 2020 by Toby Pomeroy

The jewelry industry has a chance to make a real difference in the health and quality of life for millions of artisanal gold miners, their families and communities. Metallic mercury is a permanent, potent neurotoxin that is increasingly pervasive in the global environment. We can take action to reverse this trend.

Mercury has been used to extract gold for as many as 3,000 years, yet it is a growing concern today. Why is this problem persisting and what can we do? Mercury-dependent artisanal and small-scale gold mining (ASgM) is the world’s largest source of mercury pollution. There are between 14 and 19 million artisanal and small scale gold miners in more than 70 developing countries who use mercury, a permanent, potent neurotoxin, in order to be marginally efficient in capturing gold.

They mine to live, and in the process inadvertently release approximately 8,000 lbs. of mercury into our environment every day. They are poisoning themselves and the rest of the world as mercury vapors and micro-particles are transported globally on winds and in ocean currents. Mercury use was prominent in northern California from the late 1800s until the 1960s and the environmental impact will predictably persist for centuries and beyond. Figure 1.

HOW MERCURY IS USED IN GOLD MINING

Artisanal gold miners are mostly exceedingly poor and lack sophisticated mining equipment and methods and usually mine in one of two ways. Alluvial mining consists of collecting minerals from streambed deposits, which are formed when gold has eroded from its source, then transported by water to a new locale. Miners may use a sluice, pan or some other means of collecting the heavier minerals as a concentrate. Figure 2.

In hard rock mining, a pit or shaft is dug to follow a gold vein that is excavated by the miners and carried to the surface where the ore will be concentrated. Concentration means increasing the amount of gold in relation to other minerals by selectively removing lighter particles. if employed effectively, concentration methods can greatly reduce the need for…

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