TORONTO (miningweekly.com) – Canadian precious metals producer SilverCrest Mines on Monday reported that it had started commissioning of the new 3 000 t/d counter current decantation Merrill–Crowe processing plant at its flagship Santa Elena mine, in Sonora state, Mexico.

The scheduled three-year expansion plan to transition from an openpit heap leach operation to a conventional mill and underground mine was nearing completion.

SilverCrest reported that the $99-million programme, which included drilling, a prefeasibility study, detailed engineering, the new processing plant and underground development was on budget and had experienced only “modest” delays from the original schedule.

“The mill start-up is a significant milestone in the successful development of Santa Elena and the responsible growth created by the ‘phased approach’ business plan of the company,” president and COO Eric Fier said.

He added that this significant achievement was a testament to the hard-working teams at Santa Elena and SilverCrest as the company continued to make the transition from a junior to a midtier precious metal producer.

The new processing facility and underground mine were expected to significantly increase SilverCrest’s silver and gold output this year and beyond.

The commissioning phase for the processing facility, which is expected to span about three months, would gradually increase throughput parameters from about 500 t/d until the design capacity of 3 000 t/d is reached.

Mill feed during the commissioning period would at first come from the leach pad reserve, including blending in higher-grade underground ore to start later in the current quarter. The company had already stockpiled 4 700 t of underground ore grading 1.3 g/t gold and 81 g/t silver.

During the three-month commissioning phase, metal production from the heap leach operation would continue at a reduced rate.

Underground development continues on an accelerated schedule to access underground ore for mill feed. Development work was progressing at an average rate of 10 m/d, with more than 2 800 m completed.

The decline ramp had reached the 570 m level (surface at 780 m) and five lateral levels have accessed underground reserves in preparation of stope production. Underground production equipment (company-owned and -operated) is expected to arrive on site later this quarter with immediate accelerated production from already developed stopes.

Santa Elena is located 150 km north-east of Hermosillo, near Banamichi. The mine is a high‐grade, epithermal silver and gold producer, with an estimated life-of-mine of eight years and operating cash costs of $11/oz of silver equivalent (55:1 silver to gold ratio) for the openpit heap leach and underground mine.

SilverCrest expects that the new mill would on average recover 1.5-million ounces of silver and 32 800 oz of gold a year with the current reserve.

Exploration programmes continue to make new discoveries at Santa Elena and SilverCrest had also rapidly advanced the definition of a large polymetallic deposit at the La Joya property in Durango state, Mexico.

The news on Monday edged the company’s TSX-listed stock 2.58% higher to close at C$1.99 apiece.