LONDON, UNITED KINGDOM--(Marketwire - Sept. 27, 2012) - Alexander Mining plc (TSX VENTURE:AXD)(AIM:AXM) ('Alexander' or the 'Company') -
Alexander is pleased to report that it has received notification that its MetaLeach Limited ("MetaLeach") subsidiary has been granted a patent for a Method Oxidative Leaching of Molybdenum - Rhenium Sulfide Ores and/or Concentrates in Australia, patent number 2011229125. The patent has a standard term of twenty years from 3 March 2011 (being the date of original filing), and is directed to the MoReLeach technology, a sister technology to the Company's HyperLeach® technology (patents pending).
The patent describes a method for leaching molybdenum and/or rhenium from a sulfide ore and/or concentrate containing such, the method comprising the steps of:
- Exposing the ore and/or concentrate to an aqueous solution of chlorine-based oxidising species in which the sum of the concentrations of hypochlorite and hypochlorous acid is at least 10mol% of the chlorine-based oxidising species;
- Allowing and/or facilitating the oxidation of the molybdenum and/or rhenium by the hypochlorite and/or hypochlorous acid, thereby decreasing the pH such that the predominant chlorine-based oxidising species becomes chlorine;
- Allowing and/or facilitating the oxidation of the molybdenum and/or rhenium by the chlorine thereby producing a pregnant leach solution; and
- Passing the pregnant leach solution to a means for metal recovery.
The MoReLeach Process
The MoReLeach process, a sister technology to the Company's HyperLeach® technology, is used on molybdenum bearing ores, concentrates and flotation tailings. The HyperLeach® process is a process for the extraction of base metals, especially copper, zinc, nickel and cobalt from sulphidic ores and concentrates.
The technology consists of three major stages i.e. leaching, separation/concentration and recovery. The leaching can occur either in heap or tank and involves contacting the ore/concentrate with a suitable solution of reagent at an appropriate concentration. The separation/concentration and recovery of the metals uses the same ion exchange process as that used in current roasting - acid leach plants to produce the industry standard products, ammonium molybdate and ammonium perrhenate, which can be sold directly to secondary processors. The reagent used can be readily recycled at low cost using conventional technologies.
Using MoReLeach both oxide and sulphide based molybdenum ores can be effectively treated. The reagent used is highly selective for molybdenite and can be used to remove molybdenum from copper flotation concentrates whilst minimising copper loss. This allows realisation of the value of the molybdenum, increases the copper grade and reduces penalties at the copper smelter. The rhenium which is present in all molybdenite deposits will behave in the same way as molybdenum and can be recovered at low additional cost.
Martin Rosser, Chief Executive Officer, said: "The granting of our first MoReLeach patent for the potential application of the technology described in the patent for molybdenum and rhenium ores is a significant addition to the range of metals covered by the Company's leaching technology."
Forward Looking Statements
This news release may contain forward looking statements, being statements which are not historical facts, including, without limitation, statements regarding potential mineralization, exploration results, resource or reserve estimates, anticipated production or results, sales, revenues, costs, "best-efforts" financings or discussions of future plans and objectives. There can be no assurance that such statements will prove accurate. Such statements are necessarily based upon a number of estimates and assumptions that are subject to numerous risks and uncertainties that could cause actual results and future events to differ materially from those anticipated or projected. Important factors that could cause actual results to differ materially from the Company's expectations are in Company documents filed from time to time with the TSX Venture Exchange and provincial securities regulators, most of which are available at www.sedar.com. The Company disclaims any intention or obligation to revise or update such statements unless required by law.
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.