Aluminum containing precipitating agent for precious metals and method for its use

摘要

A precipitating agent for precipitating precious metals such as gold from aqueous cyanide solution of the precious metal ions includes aluminum powder and a reducing agent such as sodium hydrosulfite, sodium borohydride or hydrazine. The precipitating agent may also include an alkali metal carbonate, such as potassium carbonate, as an activator. The precipitating agent efficiently reduces the precious metal ions to elemental metal for recovery and also consumes a portion of the cyanide content, which is often high in such solutions.