Alexander Mining reports that it has received notification that its MetaLeach subsidiary has been granted a patent for a Method of Oxidative Leaching of Sulfide Ores and/or Concentrates in the United States, patent number 9,771,631. The patent has a standard term of 20 years from the effective date of 13 June 2010 (being the date of original filing).

The patent describes a method for leaching one or more target metals from a sulphide ore and/or concentrate containing such.

Martin Rosser, Chief Executive Officer, said: “The technology described in the patent has significant potential application in the US, both for sulphide deposits and for converting sulphide concentrates, the source of the majority of the world’s base metals production and resources, through to metal at the mine site.”

MetaLeach’s HyperLeach® process, although less advanced in its commercialisation progress than AmmLeach®, has very significant potential for application. HyperLeach® is a hydrometallurgical process which has been developed by MetaLeach for the extraction of metals, especially copper, zinc, nickel, cobalt, molybdenum and rhenium from sulphide ore deposits and concentrates.

The process utilises chlorine based chemistry to solubilise metals from ores under ambient temperature and pressure conditions. The HyperLeach® process can be operated as either heap leach or tank leach.