Description

Sodium cyanide (NaCN) is a highly toxic chemical compound used primarily in the mining and chemical industries. It is a white, water-soluble solid with a faint almond-like odor (due to the release of hydrogen cyanide gas when it reacts with moisture or acids).

Key Properties:

• Chemical Formula: NaCN
• Appearance: White crystalline solid
• Solubility: Highly soluble in water
• Toxicity: Extremely toxic to humans and animals; lethal doses can be as low as 100-200 mg for an adult.

Industrial Applications:

1. Gold and Silver Mining (Cyanidation)
• Sodium cyanide is widely used in the extraction of gold and silver from ores through a process known as cyanidation. In this process, sodium cyanide solution is used to dissolve and separate precious metals from their ore by forming a soluble complex (e.g., sodium aurocyanide for gold).
• The cyanide solution is then processed to recover the metal, and the remaining waste is carefully treated to neutralize cyanide before disposal.
2. Electroplating
• Sodium cyanide is used in the electroplating industry, particularly in the electroplating of precious metals like gold, silver, and copper. The compound facilitates the deposition of metal ions onto surfaces during the electroplating process, producing a smooth, even metal coating.
3. Chemical Manufacturing
• Sodium cyanide is used as a precursor in the production of various chemicals, including cyanuric chloride, cyanogen, and nitriles. These chemicals are further used to manufacture products like plastics, adhesives, and pharmaceuticals.
• It is also used in the synthesis of organic compounds like dyes and intermediates for pharmaceuticals.
4. Organic Synthesis
• In organic chemistry, sodium cyanide is used as a reagent for various synthetic reactions, including the Strecker synthesis of amino acids and the production of nitriles, which are key intermediates in organic synthesis.
5. Metal Surface Treatment
• Sodium cyanide is used in case hardening of steel, a process where carbon and nitrogen are diffused into the surface layer of steel to improve its hardness and wear resistance. This method is commonly used for manufacturing gears and other high-wear components.
6. Pesticides and Fumigants
• Although less common today due to its toxicity, sodium cyanide has been used in pest control (e.g., for fumigating ships and buildings) and in the production of certain pesticides.

Safety and Environmental Concerns:

Sodium cyanide is highly toxic, and exposure can lead to severe poisoning or death, particularly through inhalation, ingestion, or skin contact. It can release hydrogen cyanide (HCN) gas when exposed to acids or moisture, which is extremely dangerous.

In mining, the handling of cyanide is heavily regulated due to its environmental impact. Improper disposal or accidental spills can lead to serious contamination of water sources, causing harm to aquatic life and ecosystems. Many mining operations follow stringent guidelines, such as the International Cyanide Management Code, to ensure safe use, handling, and disposal of cyanide.

Antidote:

In case of cyanide poisoning, rapid treatment with antidotes like sodium thiosulfate and hydroxocobalamin can be lifesaving. These compounds work by neutralizing cyanide or helping the body detoxify it.