Source Exploration Corp. is pleased to report results for preliminary metallurgical test work, indicating recoveries of 95% copper, 89% gold and 84% silver for its Las Minas gold -silver - copper project located in, Veracruz State, Mexico.
The metallurgical test work, included flotation testing and was undertaken by ALS Metallurgy of Kamloops, British Columbia, Canada.
Preliminary work included assessment of chemical and mineralogical characteristics, comminution tests including Bond ball mill work index and Bond abrasion, a preliminary flotation program, Davis tube magnetic separation, and a Trace Mineral Search using QEMSCAN.
Approximately 59 kilograms of sample was collected from drill core and constructed as a composite sample for test work. The average grade of the composite sample measured 2.2% copper, 1.3 g/tonne gold, and 7.0 g/tonne silver. The iron content measured 31.5%.
Metallurgical Test Results
In addition to characterization test work, a series of rougher and cleaner test were carried out to optimize a preliminary flotation flow sheet, followed by a locked cycle flotation test to test metallurgical performance under closed circuit conditions. Highlights from the test work were:
- Locked cycle test work recorded recoveries of 95% copper, 89% gold and 84% silver.
- The bulk concentrate from the locked cycle test graded 22% copper, 13 g/tonne gold and 57 g/tonne silver.
- Bond ball work index was 13.3 kW-hr/ tonne, indicating a moderately soft mineralized sample in terms of ball milling.
- Bond abrasion index was 0.14, indicating only mildly abrasive mineralized sample
Davis Tube Magnetic Separation Results
A Davis tube magnetic separation conducted on the rougher tail produced a magnetic concentrate grading 67% iron, with 65% of the iron in the tail recovered. This would be considered a high grade magnetic concentrate, which may require little further treatment to meet saleable grade requirements.
Brian Robertson, President and CEO, stated, "We are very pleased with the results from the preliminary characterization test work on mineralization from the Las Minas project. Recoveries for gold, silver and copper were excellent, and the Bond ball mill index and Bond abrasion indexes indicated that the sample tested was relative soft and only mildly abrasive. Both of these results reduce operating costs for milling operations. The high recoveries for all metals suggest the potential for the recovery of gold, silver and copper from the mineralization into a clean concentrate. Most importantly, high recoveries for all metals may be attainable without using cyanide for the extraction of precious metals. The preliminary magnetic separation suggests that a high grade magnetic concentrate can be produced, which could provide a by-product credit."
Additional test work would focus on a more comprehensive program to optimize recoveries, reagent mix and circuit design, including detailed magnetic testing on the rougher tailings to test the viability of producing iron concentrate.