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STEADY-STATE PRODUCTION ACHIEVED AT
THE HIGH-GRADE BRUCEJACK GOLD MINE

Production Update

08/10/2017

Construction and mechanical commissioning at the mine has been substantially completed, and the demobilization of construction and contract crews, as well as construction facilities, is nearing completion.  The permanent operations team has now assumed full management of the mine, and all of the main operating units in the mill are now fundamentally performing as expected.

In May, ore was first introduced to the mill with a focus on ramping up tonnage throughput to nameplate capacity as quickly as possible with low-grade ore.  During the month of June, the process plant at Brucejack processed 70,805 tonnes of ore (87.4% of one-twelfth of yearly nameplate capacity) from low-grade ore stockpiles for an average of 2,360 tonnes per day.  Under the terms of the credit agreement among the Company and its lenders, the Commercial Production Date is defined as the first day of the calendar month immediately following the first calendar month during which the process plant processes ore at an average rate of 60% of one-twelfth of yearly nameplate capacity (985,500 tonnes per year or 2,700 tonnes per day).  As a result, effective July 1, 2017, commercial production was achieved at the Brucejack Mine.

In July, the process plant at Brucejack continued to operate near nameplate capacity processing 83,667 tonnes of ore (99.9% of one-twelfth of yearly nameplate capacity) for an average of 2,699 tonnes per day from low-grade stockpiles, development muck and the introduction of stope ore.  Under the terms of the credit agreement among the Company and its lenders, the Completion Date is the first day of the calendar month immediately following the first period of two consecutive calendar months during which the process plant processes ore at an average rate of 85% nameplate capacity (985,500 tonnes per year or 2,700 tonnes per day).  As a result, the Completion Date for the Brucejack Mine is August 1, 2017. 

In June, 8,510 ounces of gold were produced from low-grade stockpiles and development muck, and in July 16,822 ounces of gold were produced from low-grade stockpiles, development muck and the introduction of stope ore for a total of 25,392 ounces of gold produced during commissioning and grade ramp-up.

Process Optimization

With the achievement of commercial production, the grade of the ore introduced to the mill was increased with a focus on optimizing recoveries in the gravity and flotation circuits.  Gold-silver doré is now being produced in the gold room and flotation concentrate is being bagged.  As the grade of ore has ramped up, doré and flotation concentrate production has increased and gold-silver inventory has accumulated.  Gold sales have commenced.

In July, while ramping up the grade of the ore to the mill, start-up issues were encountered in the mill, some of which have been addressed and others that are in the process of being resolved.  As ore has been processed, some of the gravity-recoverable gold has locked up within the voids in the SAG and ball mills.  During a scheduled shutdown in mid-July, a 4.7 kilogram grab sample was taken from material trapped behind a SAG mill liner which graded 23,547 grams per tonne gold.  This trapped gravity-recoverable gold will be recovered when the mill liners are changed (with timing dependent on liner wear).

In the gold room, doré production continues while the operation of the primary shaker table is optimized.  As the gold in the Valley of the Kings is contained in electrum with a wide range of specific gravities (with specific gravity varying with the ratio of gold to silver in the electrum), work is underway to optimize the recovery of gravity-recoverable gold.  Additionally, metallic slag has been produced as well as doré on melting the gravity concentrate from the primary shaker table. Certain of the metallic slag has a gold content of up to 35% and combined gold and silver content of over 50%.  Test work is underway to minimize the production of metallic slag and to recover the gold and silver from the slag.

In the flotation circuit, concentrate production and bagging have advanced during optimization of flotation concentrate production. Efforts are focused on reagents and dosage to maximize flotation concentrate grade.

Underground Development

Underground development continued to advance through the second quarter and subsequently reached design-level production. Long-hole drilling is currently drilling off stopes at a rate of approximately 235 meters per day. Currently six stopes are operational, four stopes are available for drilling and an additional 17 stopes are in various stages of being developed.

For the news release on the construction progress click here