Canadian junior Regulus Resources says “very encouraging” results of phase-two testing of Nuton sulphide bioleaching of samples from its primary Peru copper-gold project keep it in the running as one of several potential processing options.
CEO John Black said Regulus’ metallurgical test program previously identified material from AntaKori was amenable to the proprietary sulphide leaching technology, developed by Rio Tinto unit, Nuton.
“Conditions have been established under which attractive copper extraction is achieved from both high-sulphidation and porphyry mineralisation utilising Nuton’s bioleaching technology,” he said.
“With several other columns underway we continue to view Nuton’s bioleaching technology as one of several potential processing options for mineralisation at AntaKori.”
Regulus says evaluation of results from four test columns is focused mainly on AntaKori’s dominant enargite-rich high-sulphidation mineralisation. Three of the four columns with enargite-rich material have produced “copper extractions” of up to 88.3%. A column with chalcopyrite-dominant porphyry mineralisation got up to 87.9% extraction. The work is assessing optimum additive rates.
“Two of the columns identified conditions that produced slower extraction rates and hence less favourable conditions than the column conditions that produced the 88.3% extraction,” Regulus said.
“However, copper extractions in both of these columns continue to trend upwards.
“Four additional columns have since been started to further refine the optimal conditions … for leaching AntaKori’s enargite-rich high-sulphidation mineralisation with Nuton’s bio-leaching technology.”
Results from these columns will be reported in due course.
Regulus said its parallel resource estimation and modelling work with Compania Minera Coimolache on an integrated development project was meanwhile on track. Coimolache has the Tantahuatay oxide gold mine next door to AntaKori. The adjacent mine has deeper sulphide mineralisation.
“[Consultant] SRK Peru now has all the information they need to complete the resource estimate on the integrated sulphide project and we look forward to receiving the final results soon,” Regulus said.
