The use of Cyanide in Mining
The use of cyanide in mining has a relatively recent history, but its impact has been significant. Here's a breakdown:
Birth of a Process (1887)
The story starts in Scotland in 1887. John Stewart MacArthur, working with the brothers Robert and William Forrest, developed the MacArthur-Forrest process. This process revolutionized gold extraction by utilizing cyanide solution to dissolve gold from crushed ore.
Gold Rush and Beyond (Late 1800s - Present)
The new process arrived just in time. The gold fields of Witwatersrand, South Africa, were facing challenges extracting gold from certain ores. The MacArthur-Forrest process proved highly effective, leading to a boom in gold mining.
Over time, cyanide use expanded beyond gold. It became a common method for extracting other precious metals like silver from ores.
Advantages and Concerns
The Debate Continues (Present)
While cyanide offers an efficient extraction method, its environmental and health risks are undeniable. There's ongoing debate about its use in mining.
Regulations and stricter controls aim to minimize the risks associated with cyanide usage. Additionally, researchers are exploring alternative, less toxic methods for precious metal extraction.
Cyanide is derived from two main sources
If you'd like to delve deeper, here are some resources
Gold cyanidation: https://en.wikipedia.org/wiki/Gold_cyanidation for a detailed explanation of the process.
1 CYANIDE IN MINING: SOME OBSERVATIONS ON THE CHEMISTRY, TOXICITY AND ANALYSIS OF MINING-RELATED WATERS: https://earthworks.org/files/publications/NDG_DirtyMetalsReport_HR.pdf explores the chemistry, toxicity, and regulations surrounding cyanide in mining.
Birth of a Process (1887)
The story starts in Scotland in 1887. John Stewart MacArthur, working with the brothers Robert and William Forrest, developed the MacArthur-Forrest process. This process revolutionized gold extraction by utilizing cyanide solution to dissolve gold from crushed ore.
Gold Rush and Beyond (Late 1800s - Present)
The new process arrived just in time. The gold fields of Witwatersrand, South Africa, were facing challenges extracting gold from certain ores. The MacArthur-Forrest process proved highly effective, leading to a boom in gold mining.
Over time, cyanide use expanded beyond gold. It became a common method for extracting other precious metals like silver from ores.
Advantages and Concerns
- Cyanide's effectiveness lies in its ability to dissolve gold and silver particles. However, this very property raises environmental and safety concerns.
- Accidental spills or improper handling of cyanide can be devastating to surrounding ecosystems. Cyanide is highly toxic to fish and wildlife, even at low concentrations.
- Worker safety is another crucial aspect. Exposure to cyanide can cause serious health problems, highlighting the need for proper handling procedures.
The Debate Continues (Present)
While cyanide offers an efficient extraction method, its environmental and health risks are undeniable. There's ongoing debate about its use in mining.
Regulations and stricter controls aim to minimize the risks associated with cyanide usage. Additionally, researchers are exploring alternative, less toxic methods for precious metal extraction.
Cyanide is derived from two main sources
- Natural sources: Certain bacteria, fungi, and algae can produce cyanide. It is also found in many plants, including the pits and seeds of some fruits like bitter almonds, apricots, apples, and peaches. The cassava root, a staple food in tropical regions, also contains cyanide. In most cases, the amounts of cyanide found in these sources are too low to be harmful.
- Industrial processes: Cyanide is also produced commercially through the Andrussow process, which uses methane, ammonia, and oxygen to create hydrogen cyanide gas. This gas is then used to produce a variety of other chemicals, including plastics and fertilizers.
If you'd like to delve deeper, here are some resources
Gold cyanidation: https://en.wikipedia.org/wiki/Gold_cyanidation for a detailed explanation of the process.
1 CYANIDE IN MINING: SOME OBSERVATIONS ON THE CHEMISTRY, TOXICITY AND ANALYSIS OF MINING-RELATED WATERS: https://earthworks.org/files/publications/NDG_DirtyMetalsReport_HR.pdf explores the chemistry, toxicity, and regulations surrounding cyanide in mining.