Engineering & Mining Journal

FEB 2019

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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REGIONAL NEWS - U.S. & CANADA 10 E&MJ • FEBRUARY 2019 Falconbridge operated the complex from 1953 to 1991, producing a total of 23 million metric tons (mt) of ore at average grades of 2.4% copper and 0.3 grams/mt gold. The Springer mine produced 329,307 mt of copper at 2.54% copper and more than 200,000 ounces (oz) of gold at 0.48 g/ mt gold. The Perry mine produced 198,018 mt of copper at 2.19% copper and more than 5,800 oz of gold at 0.02 g/mt gold. Under Ex-In's ownership, considerable work went into digitizing all of the histor- ical data acquired from Falconbridge, as well as conducting further prospecting, geophysical exploration and drilling. A 2010 Ex-In drill program consisted of 20 holes for 5,700 m and demonstrated fur- ther exploration potential on the property. In 2013 and 2014, RPA was commis- sioned to evaluate the geologic potential of the complex and to develop a target re- source for the Springer and Perry mines. The study yielded a potential of between 14.5 million and 30 million mt grading 1% to 1.4% copper and 0.41 to 0.69 g/mt gold for Springer and between 0.4 million and 1.3 million mt grading 1% to 1.5% copper for Perry. Additionally, RPA delineated a potential underground target at Perry of between 2.7 million and 10 million mt grading 1.5% to 2.5% copper. Power Ore has developed an initial two- phase development plan for the current Opemiska project. Phase One will include validation of historic data; resampling of core for multi-elements, including copper, gold, cobalt, silver, and molybdenum; and geology validation, including a drill program to support an initial resource estimate and preliminary economic assessment. Phase Two will include validation of historical drill assays with a limited twinned-hole drill program, mineralization definition, ex- traction engineering and metallurgy. US Mining Fatalities in 2018 Were Second Lowest on Record The U.S. Department of Labor's Mine Safety and Health Administration (MSHA) reported that 27 mining fatalities occurred in 2018 — the second lowest number ever recorded. Eighteen fatalities occurred at surface operations and nine occurred in underground mines. Approximately 250,000 miners work across 12,000 U.S. metal/nonmetal mines, and 83,000 min- ers work in the nation's 1,200 coal mines. The leading cause of fatalities was powered haulage, which accounted for 13 fatalities or (48%) of the annual to- tal. The agency said it has taken action to counter powered haulage fatalities, including publishing a Request for In- formation seeking stakeholder input on technologies and practices that can im- prove safety conditions related to mobile equipment and belt conveyors. MSHA also launched a campaign to educate miners and mine operators on the hazards associated with such equipment. As of 2019, MSHA no longer sepa- rates coal and metal/nonmetal fatalities in this space. In 2017 and 2016, the fa- tality rates for U.S. miners were 28 and 25, respectively. Hecla's Silver Production Declines For 2018, Hecla Mining Co. announced preliminary silver and gold production of 10.4 million ounces (oz) and 262,103 oz, respectively. The company's silver production fell 17% compared to 2017. The gold figure, an increase of 13% over 2017, was a new record for the company and translates to a silver equivalent pro- duction of 43.6 million oz. The company also produced 20,091 tons of lead and 56,023 tons of zinc. "The economic engine and the compa- ny's two largest mines, Greens Creek and Casa Berardi, continue to perform strong- ly and generate significant cash flow," said Phil Baker, president and CEO, Hec- la Mining Co. "Their performance is a di - rect result of our investments, which have enabled record-setting throughput." "We continue to focus on increasing the development rate in Nevada rather than production, with the goal of setting Fire Creek up for more consistent and higher production in the future," Baker said. The Greens Creek mine in Alaska pro- duced 8 million oz of silver and 51,493 oz of gold in 2018. While silver produc- tion was lower than 2017 due to the ex- pected lower grades, the company said silver production was still on the high end of the estimates. The mill operated at an average of 2,316 tons per day (t/d) in 2018, a record for the mine. In Quebec, Casa Berardi produced 162,743 oz of gold in 2018, including 32,096 oz from the East Mine Crown Pillar pit. For the fourth quarter, 35,864 oz of gold were produced, including 4,848 oz from the East Mine Crown Pillar pit. The mine produced as expected, with an in- crease of 6,090 oz compared to 2017. The mill operated at a record of 3,791 t/d in 2018 compared to 3,551 t/d in 2017 and about 1,800 t/d more than at acquisition. The San Sebastian mine in Durango, Mexico, produced 2 million oz of silver and 14,979 oz of gold in 2018. The mill operated at an average of 429 t/d in 2018. Hecla Mining has produced 32,888 oz of gold and 172,301 oz of silver at the newly acquired Nevada operations since the acquisition in July. The company said it is focused on reorganizing the assets and increasing the rate of development, rather than production. For the fourth quarter, 19,099 oz of gold and 88,156 oz of sil- ver were produced. During that period, ore was processed at an average of 710 t/d. Production at the Lucky Friday mine in Idaho totaled 169,040 oz for 2018. The strike by union miners continues and sala- ried staff produced a limited amount of silver while making some capital improvements. The Casa Berardi mill (above) operates at a record of 3,791 t/d in 2018.

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