TORONTO (miningweeky.com) – TSX-listed Atna Resources has reported substantial progress in the ramp-up of its operations at the Pinson mine, near Winnemucca, in Nevada, saying the operation has achieved several milestones since mining was restarted last June.
Since the start of the year, the company had been able to add a second operating crew and output had shown a steady increase, averaging about 220 t/d.
The operation mined 6 930 t of ore, grading 0.38 oz/t, containing about 2 600 oz of gold, in the months of January and February.
Golden, Colorado-based Atna said it was mining both the Otto and Ogee zones, the first two of the four ore zones to be mined. New, more cost-effective, longhole mining stopes were being developed in both zones to complement the underhand cut-and-fill stoping areas in the Ogee zone. The initial bottom cut drift in the Otto zone had produced ore with an average grade of 0.53 oz/t.
Meanwhile, the company had completed a 43-m-high, steel lined, 2.7-m-diameter ventilation raise and emergency escape-way, marking the completion of all primary development projects required to achieve the 2015 mine plan at Pinson.
Atna planned to complete two additional turns to the primary access ramp, increasing the depth of the mine by about 46 m, in preparation for the 2016 mine operating plan.
During February, a third dewatering well was commissioned at Pinson. This 466-m-deep well was pumping at a rate of 69 ℓ/s and, combined with two additional operating wells, had been effective in dropping the water table below the lowest mine workings. Water inflow into mining areas had effectively been eliminated, providing dry working conditions.
Atna president and CEO James Hesketh noted that more personnel were being added at Pinson with the goal of increasing the operating rate to 24 hours, seven days a week and an ultimate production rate of about 450 t/d to 550 t/d later in the second half of 2015.
Atna expected to produce between 55 000 oz and 65 000 oz from Pinson and its Briggs mine, in California, this year.