Cyanides are a group of compounds based on a common structure formed when elemental Nitrogen and Carbon are combined. Cyanide solutions readily bond with gold, silver and other metals, which is why the mining industry uses it. Cyanide is usually stored and transported as solid. It is stable when dry. Most cyanide solids will dissolve in water to produce toxic cyanide gas. Cyanide gas is colorless and smells like bitter almond. Cyanides are naturally produced by certain bacteria, fungi, and algae, and may be found in food and plants. When cyanide combines with metals and organic compounds, it forms simple and complex salt and compounds. Sodium Cyanide is mainly used in electroplating, metallurgy and the production of organic chemicals, in photography developments and also in making plastics. A minor use of cyanide is in the manufacture of dyes and pigments.
Heat Effects
Cyanide is highly toxic. Cyanide poisoning can occur through inhalation, ingestion, and skin or eye contact. Exposure to large amount s of all form of cyanide for a short time can harm the brain, lungs, heart and can cause coma and death. One teaspoon of a 2% solution can kill a person. In general, fish and other aquatic life are killed by cyanide concentrations in the microgram per liter (part per billion) range, whereas bird and mammal deaths result from cyanide concentrations in the milligram per liter (part per million) range. Evidence shows that cyanide compounds linger in affected plant and fish tissues and can persist in the environment for long periods of time. Cyanides react with many other elements and are known to breakdown into several hundred different cyanide – related compounds.
How is cyanide used in mining?
Cyanide – leaching allows mining companies to reopen and expand mines containing what were previously unprofitable minerals reserves. There are two types of cyanide – leaching processes used by the modern mining industry. Vat –leaching, where extracted ore is combined with cyanide in vats, and heap-leaching, in the extraction of copper, nickel, cobalt and molybdenum, cyanide is used during the milling and concentration processes.
World consumption of Sodium Cyanide is about 700 thousand metric tons, with a value of about $ 600 million. The marketing of Sodium Cyanide is dominated by a few large products, primarily DuPont and Cyplus. Sodium Cyanide is used throughout the world, mainly as a reagent in the mining industry for the isolation of precious metals. About 70% of Sodium cyanide is used for processing, it has also use as a chemical intermediate, especially in locations where there is not a local supply of hydrogen cyanide, since sodium cyanide can be transported and stored.
The Sodium Cyanide market has changed quite a bit in recent years as a result of impressive rise in gold prices. Gold mining companies are investing capitals in new exploration projects and also prolonging activities in mines that were winding down.
This has resulted in increased demand for Sodium Cyanide and growth is expected to continue during the forecast period.