New Jersey Mill in Kellogg, Idaho
New Jersey Mill History
In 2011, NJMC signed a joint venture (JV) agreement with United Mine Services (UMS), a wholly-owned subsidiary of United Silver Corporation, to increase capacity at the mill. UMS funded mill expansion at a cost of approximately $3.2-million. NJMC is manager of the JV and retains a 65% interest in JV assets. The Company has the right to process its own ore at the rate of 3,000 tpm and allocates unused and excess capacity in its role as manager.
From late-2014 through late-2015, the Company successfully processed ore from the nearby Golden Chest Mine at the New Jersey Mill. The New Jersey Mill processed a total of 40,840 dry metric tonnes of ore from the Golden Chest Mine with an average head grade of 6.70 gpt gold and with recovery averaging 92.3%. Concentrate grades averaged 435 gpt gold, although the last concentrates assayed in excess of 1,000 gpt gold. In total, the mill produced approximately 8,000 ounces of gold.
In addition to producing concentrates, NJMC leached approximately 10 tonnes of flotation concentrate, produced from Skookum ore, in the CLP at the New Jersey Mill. An improved leaching process that employs a Carbon-in-Leach finishing tank was tested, with objectives of reduced process time and increased gold recovery. Test results provided an understanding of which capital improvements to the leach circuit will be necessary to reach these objectives and also, as expected, confirmed that Skookum concentrates are amenable to leaching.
The New Jersey Mill has demonstrated its value as a regional processing center. It can perform test and toll milling on material from mines and prospects within a wide radius of active mining camps in Montana, Idaho, and Washington.