Northern Vertex Mining Corp. reported gold and silver production totaling 2,837 gold equivalent ounces (2,580 oz gold and 18,051 oz silver) during June and initial results from its heap-leach pad study at the Moss gold mine, located in northwest Arizona, USA.
“[This] concludes our strongest quarter to date and we expect to see continued improvement during the next fiscal year,” said President and CEO Kenneth Berry. “In addition, recent modifications to our Merrill Crowe facility have resulted in our single largest gold shipment of $1.2 million representing nine days of production. Furthermore, initial heap leach study results confirm feasibility predicted recoveries, meaning a significant portion of the contained gold and silver inventory is expected to be drawn down in the following two quarters.”
During the second quarter, the Moss gold mine moved more than 1.7 million metric tons (mt), which included 419,000 mt of ore. More than 561,000 mt were stacked on the leach pad. The mine produced 7,482 oz of gold and 45,876 oz silver during the quarter.
The Moss team initiated a recovery study of the heap leach pad in May to confirm consistent moisture percolation throughout the pad and to measure solution volume and grade retained in various areas of the pad. This would help determine the gold and silver inventory remaining on the pad. By obtaining additional samples for further bottle roll testing, they hoped to estimate the amount of gold inventory that can be recovered by re-leach. Using that information, they could sign and implement a leach solution application plan to recover additional gold from the leach pad inventory.
The results from the first panel, the Central Panel, which contains approximately 235,000 mt of ore, showed remarkable consistency in the percolation of solution, both laterally and vertically, the company said. Furthermore, the study confirms there are no dry areas, channeling is not occurring, the pad is retaining its moisture as expected and that the recoverable gold and silver in inventory will meet or exceed feasibility predicted recoveries. The full study will include an additional five panels and is ongoing.
“The results from the Central Panel indicate there are approximately 5,000 oz of recoverable gold contained in this area, of which an estimated 3,000 oz have already been dissolved in the water held in the heap and need only to be flushed and collected,” said Jim Gubler, process manager, Northern Vertex Mining. “With the leach solution application plan that we have designed, we are projecting that a significant portion of this gold will be recovered over the next several months, which should add to our normal monthly production.”
The company said it has made progress in correcting issues that have hampered the Merrill Crowe process plant since startup. Modifications to the filter press piping, clarifiers and vacuum pump system are nearing completion. There has been a significant decrease in reagent consumption and an immediate improvement in recoveries of gold and silver from the pregnant solutions, the company added.