Cora Gold scoping study level metallurgical testwork results

Highlights

• Metallurgical testwork undertaken by Wardell Armstrong International (WAI) to a level considered suitable for inclusion in a Scoping Study.
• Samples were selected to represent different host lithologies and depth profiles.
• Approximately 207 kg of oxide material was tested, from the Selin, Zone A and Zone B prospects.
• The more competent sap rock, derived from deeper in the weathering profile, was characterised as ‘very soft’ on the crusher, abrasion and rod mill work indices, and ‘medium’ on the Bond Ball Mill Index.
• In whole ore leach tests, all the lithological groups reported gold (Au) recoveries ranging from 92.4% - 96.7% without oxygen addition, using an optimised 106 micron grind size and a relatively low concentration of cyanide (0.5 g/l).
• Combined Au recovery into a gravity concentrate with leached tailings ranged from 95.4% - 98.3%. Test work on the extraction of gold from the concentrate itself was inconclusive with further work recommended.
• Testing for environmental characteristics confirmed that the leach residues are neither acid generating nor carry toxic elements at hazardous levels.
• A column leach test over 95 days was continuing to leach Au when the programme was suspended with 56% Au recovery recorded at that time.

Jonathan Forster, CEO, commented: “The results from this comprehensive Scoping Study level of metallurgical testwork on a variety of oxide ore types and depths at Sanankoro has continued to yield a very encouraging characteristics profile for the processing of oxide gold. The confirmation that the oxides are soft and will require only moderate grinding to a relatively coarse grind size, with only modest concentrations of cyanide and yet still able to generate gold recoveries well in excess of 90%, is particularly welcome. This points to the potential for a lower cost processing route, which in conjunction with anticipated lower mining costs, should help to support the ongoing Scoping Study.

Although gold recoveries from the column leach don’t match that of the cyanide leach approach, it is reassuring that the result obtained is considered a minimum with further upside potential if a programme is pursued over a greater length of time. This work shows that heap leach, with expected lower capex, may still be considered as an option.”

Read the article online at: https://www.globalminingreview.com/exploration-development/22102019/cora-gold-scoping-study-level-metallurgical-testwork-results/