Alexander subsidiary MetaLeac has been granted Canadian patent 2,693,217 for a method for ammoniacal leaching.
This patent forms part of MetaLeach's family of core AmmLeach technologies. The patent will remain in force until 11 July 2028.
Chief executive Martin Rosser said: "We are delighted with the grant of our patent for a method for ammoniacal leaching in Canada, a country with a major mining industry.
"The patent is the overarching AmmLeach patent in our intellectual property portfolio and underpins all applications of the AmmLeach technology."
At 1:20pm: (LON:AXM) Alexander Mining PLC share price was +0.02p at 0.24p