Patent Granted in Zambia

26 February 2018

Alexander Mining plc

('Alexander' or the 'Company')

Patent Granted in Zambia for a Method for Leaching Cobalt from Oxidised Cobalt Ores

Alexander is pleased to report that it has received notification that its MetaLeach Limited ("MetaLeach") subsidiary has been granted an African Regional I.P.O. ("ARIPO") Patent in Zambia for a Method for leaching cobalt from oxidised cobalt ores, patent number AP 4394. The patent has a standard term of twenty years from the effective date of 6 August 2010 (being the date of original filing of the PCT Application from which the ARIPO patent is derived).

Martin Rosser, Chief Executive Officer, said:

"The technology described in the patent has potential application for the extraction of cobalt from a range of oxidised or non-sulphide deposits. Cobalt, an essential component of lithium ion batteries, is a core target metal for the commercialisation of our intellectual property and we now have patent protection coverage in Zambia, one of the world's most prospective countries of patent use."

The patent describes a method for leaching cobalt from a non-lateritic oxidised cobalt ore, comprising the method steps of:

· curing the non-lateritic oxidised cobalt ore to be leached through the application of an aqueous solution of a cobalt reducing agent selected from the group: iron (II) salts, sulphite salts, sulphur dioxide, and combinations thereof; at a pressure of between about atmospheric pressure and about 5 atmospheres, at a temperature between about 5°C and about 65°C;

· wherein the pH of the aqueous solution of the cobalt reducing agent is between about 1.0 and 10.0; and wherein the relative volumes of the aqueous solution of the cobalt reducing agent and the non-lateritic oxidised cobalt ore to be leached are such that the combination of the aqueous solution of the cobalt reducing agent and the non-lateritic oxidised cobalt ore to be leached forms a mixture with a solids content not less than about 100 g/L of aqueous solution;

· substantially retaining the aqueous solution of the cobalt reducing agent in contact with the non-lateritic oxidised cobalt; and

· leaching the cured ore at a pressure of between about atmospheric pressure and about 5 atmospheres, at a temperature between about 5°C and about 65°C, through the application of an ammonium carbonate solution containing free ammonia thereby producing a pregnant leach solution; then passing the pregnant leach solution resulting to a means for cobalt recovery.

ENDS

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