Gold mining has long been a dirty process, but the environmental costs have been rising. As gold deposits become depleted and demand for gold increases, more and more gold is being mined using environmentally destructive practices. Open-pit mining, cyanide heap leaching, and amalgamation are dirty gold practices found throughout the world.
Two-thirds of newly mined gold is now recovered using an environmentally harmful practice known as open-pit mining. In open-pit mining, mining companies reach the gold-laden rock (known as ore) by digging or blasting from the ground level, creating vast craters. In the past, it was more common for mining companies to obtain ore by digging underground tunnels. But with rich gold deposits becoming hard to find, companies increasingly rely on open-pit mining because it is a cheap way of recovering trace amounts of gold spread across large land areas.
Unfortunately, open-pit mining destroys the landscape, opening up holes in the ground so large that they can be a mile wide and visible from outer space. The other problem with open-pit mining is waste. After the ore is brought to the surface, it must be processed to extract the gold. Only 0.000001 percent of the ore obtained through open-pit mining consists of gold. The rest must be discarded. It is estimated that open-pit mining creates at least 20 tons of toxic waste for every 0.333 ounce gold ring.Open-pit mining,
No Dirty Gold
A technique called “heap leaching” is commonly used to extract gold from ore. In heap leaching, the ore is crushed into fine particles. It is then heaped into large piles and sprayed with cyanide, which trickles down through the ore and bonds with the gold. The resulting gold-cyanide solution is collected at the bottom of the heap and pumped to a mill, where chemicals are used to separate the gold from the cyanide. One round of heap leaching usually takes a few months.
Heap leaching leaves behind large amounts of toxic waste laden with cyanide and heavy metals. To dispose of this waste, mines often construct a dam and place the waste inside. These dams, however, are not always structurally unsound. They can leak or even fail. And because they are not dismantled after mine closure, remaining behind permanently, each new dam creates a long-term environmental hazard.
No Dirty Gold
Brilliant Earth Blog
Mercury amalgamation is the gold extraction method most often used in artisanal, or small-scale, gold mining. Although it is a simple and effective technique, it poisons the environment and creates grave health risks.
In mercury amalgamation, miners bring mercury into contact with sediments containing gold, or with gold-laden rock crushed into fine particles. The gold in the sediments or particles bind with the mercury, forming an alloy called amalgam. The mercury is then removed from the amalgam by dissolving it in nitric acid or by evaporating it with heat. The gold remains behind.
More gold is being extracted using mercury amalgamation as gold prices rise and people in developing countries increasingly turn to gold mining. The process, however, is extremely dangerous for miners. The vapor released by mercury amalgamation has been proven to cause neurological damage and harm the kidneys, liver, heart, lungs, colon, and immune system. When pregnant women are exposed to mercury, it can cause neurological damage in unborn children.
There are about a million artisanal diamond diggers in Africa who live in extreme poverty. For the last century they’ve been mostly forgotten, left... Read More
Every day, it’s becoming clearer that the Ebola outbreak in West Africa needs a much stronger global response. Brilliant Earth wants to help. Today... Read More