potassium cyanide

chemical compound

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Last updated

July 1, 2026

Quick Summary

Potassium cyanide is a highly poisonous crystalline salt with the chemical formula KCN. It is primarily used in the extraction of gold and silver from ore.1

Sir George Thomas Beilby developed a process for manufacturing potassium cyanide by heating a mixture of charcoal and potassium carbonate with ammonia. This method was crucial for meeting the growing demand for cyanide, particularly for its use in extracting gold from low-grade ores.2

Potassium cyanate (KOCN) is a related crystalline salt, distinct from potassium cyanide. It is used to kill crabgrass on lawns.3

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wet-collodion process
…of sodium thiosulfate, for which potassium cyanide was later substituted. Immediate developing and fixing were necessary because, after the collodion film had dried, it became waterproof and the reagent solutions could not penetrate it. The process was valued for the level of detail and clarity it allowed. A modification of…
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…of sodium thiosulfate, for which potassium cyanide was later substituted. Immediate developing and fixing were necessary because, after the collodion film had dried, it became waterproof and the reagent solutions could not penetrate it. The process was valued for the level of detail and clarity it allowed. A modification of…
Read More

Sir George Thomas Beilby
…developed the process of manufacturing potassium cyanide by passing ammonia over a heated mixture of charcoal and potassium carbonate. This process helped meet the increased demand for cyanide for use in extracting gold from low-grade ores.
Read More
…developed the process of manufacturing potassium cyanide by passing ammonia over a heated mixture of charcoal and potassium carbonate. This process helped meet the increased demand for cyanide for use in extracting gold from low-grade ores.
Read More