The plant has been treating high grade ore averaging 16.5 g/t gold since mid-May. Gold recovery will probably be above 90%, but a few more weeks of operating data will be needed for certainty.
The plant had minor start-up issues in both circuits, but they were resolved in early May. Difficulties were encountered in getting cyanide concentrations up to the required levels in the cyanidation reactor and a shortage of filter press cloths.
To make up for the delay in plant start-up, Mako intends to process only high grade vein material until the end of June.
The open pit mine is averaging 982 tonnes of ore daily. A 105,856-tonne stockpile includes 17,596 tonnes of diluted vein material grading 15.37 g/t gold and 88,260 tonnes of historical dump material at 2.47 g/t for 16,676 oz. of total contained gold.
The start of mining in the Porcelana zone is to begin early in the third quarter 2021. This zone has the high grade and thickness profile encountered at the mine.
The November 2020 estimate for the pit has fully diluted measured and indicated resources of 310,900 tonnes grading 9.54 g/t gold, containing 95,400 oz. of gold. The fully diluted inferred resource is 226,700 tonnes grading 8.50 g/t gold, containing 62,000 oz. of gold.
The estimate for potential underground mining includes measures and indicated material of 230,600 tonnes at 11.22 g/t gold, containing 83,200 oz. The inferred portion is 116,100 tonnes at 8.42 g/t gold, containing 51,200 oz.
The historical dumps are classified as inferred having 78,800 tonnes at 2.95 g/t gold, containing 7,500 oz.
(This article first appeared in the Canadian Mining Journal)
