Tomra reported very optimistic outcomes. Not solely was the quantity of fabric that will doubtlessly be processed diminished by roughly 50%, however the grade additionally roughly doubled, and gold restoration was roughly 97%. The grade of fabric within the +38-65.5-mm dimension fraction went as much as 22.9 g/t gold from an preliminary grade of 11.2 g/t. The grade of fabric within the +12.7-38-mm dimension was elevated to 19.5 g/t gold from 11.8 g/t. When the coarser fraction was mixed with the fantastic, -12.7-mm portion, the grade improved to 16.6 g/t gold.
Rejects from the sorting course of represented 34% of the feed quantity and graded 0.7 g/t gold, appropriate for mine backfill.
Ore sorting has the potential advantages of lowering the quantity of ore that have to be milled, a financial savings within the dimension and price of the mineral processing plant. With much less materials going by way of the plant, the quantity of tailings can also be diminished. There are additionally important financial savings in trucking prices and inexperienced home fuel emissions from diesel engines.
The Hammer down deposit was mined between 2000 and 2004, eradicating a complete of 291,400 tonnes of ore grading 15.83 g/t gold and recovering 143,000 oz. of gold.
Maritime estimates the Hammerdown, and close by Orion pit constrained measured and indicated useful resource at a 1.0 g/t cut-off is 1.7 million tonnes grading 6.65 g/t gold, containing 368,000 oz. The inferred useful resource (together with Intervein) is 1.3 million tonnes at 4.77 g/t gold, containing 206,200 oz.
(This text first appeared within the Canadian Mining Journal)