Cyanides were first used as chemical weapons in World War I and are highly toxic to humans. Cyanides exist in various forms — liquid or gaseous hydrogen cyanide and alkali salts of cyanide — and can enter the body through inhalation, ingestion or absorption through the eyes and skin.
In accordance with Occupational Safety and Health Administration standards, safe exposure of cyanide cannot exceed 10 parts per million (ppm), with health dangers beginning at 50ppm.
Cyanide is extremely deadly — inhaling a concentration of about 2,000 ppm of hydrogen cyanide gas for a minute is enough to cost one’s life, while the lethal oral dose of cyanide salts is 200-300mg. Two notorious incidents, the Jonestown Massacre in 1978 and the Tylenol poisonings in 1982, have illustrated the lethality of this poison.
More than 900 people died in a mass murder-suicide in 1978 by drinking cyanide-laced punch at the order of cult leader Jim Jones in Jonestown, Guyana in South America. In 1982, someone tampered with capsules of Tylenol in Chicago and turned them lethal with potassium cyanide. This led to seven deaths, and this number rose subsequently due to copycat attacks.
Despite the apparent and acute dangers of cyanide, cyanide is still being used in the gold mining industry to extract gold from ores. This has resulted in numerous high-profile cyanide leaks, with a 2011 report on cyanide use at mine sites claiming that more than 30 major accidents involving cyanide have occurred worldwide in the past 25 years.
One of the most severe cyanide leaks in history is the tailings dam burst at the Baia Mare Aurul gold mine in North Western Romania in 2000. It released 100,000 cubic metres of wastewater, heavily contaminated with cyanide, into the Lapus and Somes tributaries of the river Tisza (one of the biggest rivers in Hungary). In addition to ecological damage, the cyanide pollution in the river Tisza posed a significant threat to human health, with cyanide concentration in the upper part of the river being 100 times more than the limit value for drinking water.
Considering the high toxicity of cyanide and the repeated occurrence of cyanide accidents in gold mining, shouldn’t the use of cyanide be eradicated?
Clean Mining, part of Clean Earth Technologies, has a non-toxic solution to eliminate cyanide use in traditional mining processes. It uses a water-soluble gold recovery agent and is applicable to a range of ores for responsible mining operators. Not only is the Clean Mining solution better for the health and safety of mine employees, the environment, and local communities, it delivers similar gold recovery rates to cyanide.
With the use of Clean Mining’s solution, gold mining can take place without deadly cyanide and yet still be efficient.