MINERAL PROCESSING: Toll milling Halfmile ore creates good quality concentrates

NEW BRUNSWICK – A 30,000-tonne sample of ore from the Halfmile Zn-Pb-Cu mine demonstrated excellent flotation characteristics, good metal recoveries and quality concentrates when custom treated at Xstrata’s Brunswick concentrator. The Halfmile project, roughly 60 km southwest of Bathurst, is owned by Trevali Mining of Toronto.

Trevali said the sample was processed over a four-day period. The report by the company’s metallurgical consultant, Holland and Holland, said that the Halfmile mineralization exhibits superior flotation characteristics and uses less reagent to produce concentrates of similar to slightly superior quality to those traditionally produced in the Bathurst Mining Camp.

The initial mill run focused on zinc recovery, and it was found to be over 86%. A concentrate grading 53% Zn, 2.57% Pb and 0.46% Cu plus precious metals was made. The next run will treat 40,000 to 50,000 tonnes of feed from Halfmile and test zinc regrind parameters and increased by-product recoveries, including lead liberation and pyrite suppression studies.

Trevali is in the process of acquiring the nearby Caribou mill and mine complex so that it will own a suitably sized mineral processing facility for Halfmile ore.

Please visit Trevali.com.