A process is disclosed for recovering cyanide used to leach gold or silver from ore. In the course of leaching gold or silver from ore, a barren solution is generated. A portion of the barren solution containing sodium cyanide is recycled to the cyanidation process while blowdown from the barren solution is subjected to pre-treatment, UV photodissociation and pH adjustment. Ultimately, a volatile hydrocyanic acid is formed and is absorbed into a sodium hydroxide solution through the employment of a gas-filled membrane. This forms sodium cyanide that can be recycled and used in the cyanidation process to leach gold or silver from ore.

A process is disclosed for recovering cyanide used to leach gold or silver from ore. In the course of leaching gold or silver from ore, a barren solution is generated. A portion of the barren solution containing sodium cyanide is recycled to the cyanidation process while blowdown from the barren solution is subjected to pre-treatment, UV photodissociation and pH adjustment. Ultimately, a volatile hydrocyanic acid is formed and is absorbed into a sodium hydroxide solution through the employment of a gas-filled membrane. This forms sodium cyanide that can be recycled and used in the cyanidation process to leach gold or silver from ore.

The present invention provides a process of coating at least a portion of a substrate surface comprising contacting the surface with hydrogen cyanide monomeric units under conditions permitting polymerisation of the hydrogen cyanide monomeric units to form a polymer that coats the surface. Also provided is a substrate coated by a polymer according to the claimed process. Also provided is a method of forming a hydrocyanic acid-based hydrogel, the method comprising co-polymerisation in a solution, the solution comprising hydrogen cyanide monomer units and co-monomers.

The present invention provides a process of coating at least a portion of a substrate surface comprising contacting the surface with hydrogen cyanide monomeric units under conditions permitting polymerisation of the hydrogen cyanide monomeric units to form a polymer that coats the surface. Also provided is a substrate coated by a polymer according to the claimed process. Also provided is a method of forming a hydrocyanic acid-based hydrogel, the method comprising co-polymerisation in a solution, the solution comprising hydrogen cyanide monomer units and co-monomers.