Abstract: A process for treatment of waste aqueous process streams from industrial process containing both cyanide ions and dissolved ammonia to reduce the cyanide content, comprising the consecutive steps: (a) adding a halogenating agent to the solution while maintaining the pH of the solution at greater then 7; (b) removing ammonia from the solution by aeration; (c) acidifying the solution to a pH of less then 7; (d) substantially neutralizing the solution; and (e) removing the ammonia from the solution by aeration.

Abstract: The present invention provides in one aspect a process in which a particulate material containing water and having adsorbed thereon a solubilized gold compound is located in packed form in a fractionating column, a liquid containing a major proportion of water miscible organic liquid is boiled in an evaporator such that it enters the packed fractionating column as a vapor, said water miscible organic liquid being more volatile than water and being preferentially retained in the column.The present invention provides in another aspect a method of recovering gold from an aqueous solution, which comprises placing the gold containing aqueous solution in a cell comprising a gold, silver, aluminium or copper cathode and an inert electrode, subjecting the solution to electrolysis in the cell so as to deposit a gold foil on the cathode.