Yamana Gold reported on April, 8 that its Brazil-focused subsidiary, Brio Gold, is conducting detailed metallurgical testwork to assess identified options to modify the process flowsheet at its currently inactive C1 Santa Luz mine, with results expected by mid-2015. Detailed pilot plant testwork and the resulting final process flowsheet are expected to provide certainty of the viability of reactivating C1 Santa Luz and support the required capital spending.
Processing options being tested include gravity circuit enhancements, flash flotation optimization, organic carbon reduction through kerosene conditioning, and carbon-in-leach circuit improvements. Ore samples representing a cross section of ore types have been prepared and sent for bench-scale laboratory testwork. Representative bulk tonnage ore samples totaling 15 mt have been prepared for full pilot plant testing, pending the results of the bench-scale work, with pilot plant testing expected to begin in the second quarter.
Subsequent to a decision on a C1 Santa Luz flowsheet modifications, infill and geotechnical drilling will resume at the project in support of an updated mine plan design.
Brio Gold expects operating and capital cost estimates for C1 Santa Luz modifications to be determined by mid-2015. Engineering design is planned to begin in the third quarter, and plant modifications are expected to take place during the first half of 2016. Commissioning is planned to begin by mid-2016.
At full production, the mine is expected to produce about100,000 oz/y of gold, lifting Brio Gold’s production to about 230,000 oz/y. Total capital spending at C1 Santa Luz is currently expected to be in the range of $20 million to $30 million, beginning in mid-2015 and with most of the spending taking place in 2016.
Yamana Gold formed Brio Gold in December 2014 to hold its Pilar, Fazenda Brasileiro, and C1 Santa Luz mines in Brazil and Agua Rica development project in Argentina (E&MJ, January 2015, p. 15). During the first quarter of 2015, the Pilar mine produced 19,000 oz of gold, and the Fazenda Brasileiro mine produced 12,000 oz of gold.
Yamana reports that more efficient mining and dilution control are continuing to improve production and operating costs at Pilar. Development work at the satellite Maria Lazarus deposit is ongoing, with approximately 1,700 m of development completed as of early April. Maria Lazarus is expected to ramp-up over the remainder of 2015 and provide additional flexibility at the operation.
At Fazenda Brasileiro, upgrading of the carbon-in-leach circuit was accelerated into the first quarter to enhance operational flexibility. Production and costs were expected to normalize to higher and lower levels, respectively, beginning in the second quarter.
Yamana is currently working toward taking Brio Gold public in the third quarter of 2015 and has engaged National Bank Financial and CIBC World Markets as financial advisors to assist in the going-public process.