Virdis Mining & Minerals (ASX:VMM) has described a metallurgical breakthrough processing its ore with neodymium recovery of 76% clocked in the lab.
The finding comes after the company sent off samples to ANSTO, Australia’s nuclear regulator.
That entity has a testing lab which must process rare earths given the elements are often radioactive, in close proximity to monazite and thorium and other radioactive compounds.
Virdis sent off 40kg of rock to ANSTO with a view towards testing recovery rates, and, “optimising … flowsheet design which produces a mixed rare earth carbonate.”
The 40kg was made up mostly of diamond drill core samples and boasted a head grade of 4,472ppm total rare earth oxides (TREO). Of that, 32% were higher-value magnetic rare earths (a class to which neodymium and praseodymium belong.)
Recoveries were achieved using a standard ammonia sulfate test and 30 minute leach cycle.
The company interprets the data to show that overall recoveries improve at a pH level higher than 4.5.
“The excellent recoveries of the magnetic rare earths, at lower molar concentrations and higher pH’s, will go a long way in reducing the operating costs and bodes well for the project economics,” Virdis CEO Rafael Moreno said.
“The higher pH conditions have also resulted in even lower levels of radionuclides and gangue elements in the leached solution. This helps reduce the complexity and quantity of reagents required in the downstream processing facilities.”
VMM last traded at 86.5cps.