Alexander is pleased to report that it has received notification that its subsidiary, MetaLeach Limited (“MetaLeach”), has been granted a patent for a Method for Ammoniacal Leaching (Chile patent number 54.919).  This patent forms part of MetaLeach’s family of core AmmLeach® technologies and has a standard term of 20 years from the effective date of 11 July 2008 (being the date of original filing).  The patent is the overarching AmmLeach® patent in our intellectual property portfolio and underpins all applications of the AmmLeach® technology.

Martin Rosser, Chief Executive Officer, said: “We are delighted with the grant of our patent in Chile for a Method for Ammoniacal Leaching.  Chile is the world’s largest producer of copper and a leader in copper heap leaching.  We believe that there are significant opportunities in the country where AmmLeach® has major benefits compared to conventional acid leaching methods.”

The granted Chile patent encompasses methods for leaching one or more target metals from an ore, the methods comprising the steps of: curing the ore to be leached through the application of an aqueous solution of a curing agent, producing a cured ore; leaching the cured ore at atmospheric pressure through the application of an ammonium carbonate solution containing free ammonia, producing a pregnant leach solution; and passing the pregnant leach solution to a means for metals recovery.


For further information, please contact:


Martin Rosser

Chief Executive

Mobile: +44 (0) 7770 865 341



Alexander Mining plc

Tel: +44 (0) 20 7078 9566

Email: [email protected]

Website: www.alexandermining.com




Northland Capital Partners Limited 

Matthew Johnson / Dugald J Carlean

(Corporate Finance)

John Howes

(Corporate Broking)

Tel: +44 (0) 20 3861 6625


Turner Pope Investments (TPI) Ltd

Andy Thacker

Tel: +44 (0) 20 3621 4120



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