New Jersey Mining Co. (NJMC) recently shipped approximately 100 metric tons (mt) of gold concentrate in five 20-mt lots from its New Jersey Mill in Kellogg, Idaho. The flotation concentrates are derived from ore produced at the nearby Golden Chest mine by Juniper Mining. Proceeds from the sale of the concentrates accrue to Gold Hill Reclamation and Mining, the lessee of the Golden Chest mine. NJMC processes the ore at its New Jersey Mill, generating cash from milling fees and its share of a 2% NSR royalty on gold production.
The flotation concentrates contain gold, silver and significant base metal (zinc and lead) sulfides. The total gold contained in the shipped concentrate is estimated at 540 troy oz; and gold recovery continues to average approximately 94%. The mill concentration factor or the ratio of the gold grade of the concentrate to that of the ore has been greater than 35:1, exceeding expectations.
The Golden Chest mine commenced ore production in December 2014 and is operating in a ramp-up period, during which development is driving to deeper levels while ore production is building toward design capacity of approximately 300 mt/d. The gold grade of the concentrates has increased with each 20-mt lot, reflecting the progression of mining from the upper margin of the orebody down into the higher-grade core of the deposit, according to the company.