The Toronto-listed company (SMT) said this week its focus on processing higher-value ore, to take advantage of stronger metal prices, saw revenue from payable metals surge 43% year-on-year to US$205.1 million while operating cash flow hit $79.8 million in 2017 compared with $44.3 million in 2016.
EBITDA of $81 million in 2017 was 93% higher yoy.
Sierra said record throughput at Yauricocha in Peru (14% higher in 2017) offset lower output at its mines in Chihuahua, Mexico. But it is promising improved performance at 100%-owned Bolivar and Cusi in 2018.
"Similar to the successful program at Yauricocha in Peru, which began in 2015, the company has engaged in an operation turnaround program in Mexico to modernize operations, improve production, and lower costs," Sierra said.
"The company has already realized a 2% increase in throughput at Bolivar and a 23% increase at Cusi in Q4 2017 compared to Q3 2017, and further throughput increases are expected to continue during the first half of 2018.
"[The] Mexican operations have seen quarterly improvements over the last two quarters. At Bolivar, there have been increases in tonnage as a result of new equipment purchases, which have allowed more minable stopes to be incorporated into the mine plan.
"At Cusi, the company has changed its focus from mining the existing narrow vein structures to the recently discovered Santa Rosa de Lima zone, which has significantly larger widths and higher grades.
"Cusi reported a significant improvement in metal recoveries, and [higher] 2018 guidance is based on projections which reflect the potential for record silver production and lower costs, as a result of the restructuring program performed during the second half of 2017, which focused on the mining of the Santa Rosa de Lima structure.
"Both mines have also benefitted from successful improvement efforts in metallurgical recoveries, which have increased during Q4 2017 compared to previous quarters."
Sierra president and CEO Igor Gonzales said near-mine exploration programs "remain a growth component at all three of our mines in 2018 and we are very optimistic that these programs will continue to add high value tonnage going forward".
"When combined with our continued production optimization program, it should result in substantial growth, not only in production with lower costs, but most importantly in shareholder value."
Sierra's share price hit a 12-month high back in April, 2017, of C$3.68. It was at $3.40 overnight, capitalising the company at C$553.6 million.