Harte is capitalised at about C$160 million at Thursday's 26c close in Toronto (TSX: HRT). It was above 40c at the start of the year and reached a one-year high of 55c back in September last year.

UK-based Appian Natural Resources Fund owns more than 20% of the company.

Last month it closed a US$72.5 million credit deal with BNP Paribas as it took in US$10 million more of Appian equity finance.

Harte CEO and president Stephen Roman said this week June production numbers were "forthcoming" after Sugar Zone produced 5,476oz in April and 5,438oz in May.

"Mill throughput continues to perform as expected and 800 tonnes per day has been achieved," Roman said.

"Our focus continues to be on the ramp-up of underground operations. We are reinvesting cash flow from gold production into underground development and will continue to do so for the remainder of this year."

Mined ore was coming from sill development and stopes in the Sugar Zone south area while surface stockpiles were being drawn to "supplement underground mine production in May and June". Stope production from the Sugar Zone north limb is expected by September. Mined stopes were "coming out as planned with minimal external dilution" but ore production was below target in May and June due to "lack of stope availability and ventilation development, reducing daily performance".

"Ventilation work was recently completed and mine performance will improve as post-blast smoke clearing will be more efficient," the company said.

"When the Sugar Zone north and south limbs are both operational, the company expects to supply the mill solely from run-of-mine production. The company is on track to achieve this by Q4 2019, consistent with the feasibility study plan.

"Mill operations are stabilized and have demonstrated the capacity to run at 800tpd while maintaining planned recoveries."

Harte declared commercial production at Sugar Zone back in January this year after earlier ‘bulk sampling' 70,000t of underground material that was processed at Barrick Gold's nearby Hemlo plant.

Permitting to increase mine and plant throughput to 800tpd was received ahead of expectations. Now the company will be weighing further expansion to 1,200tpd, as planned, which could lift output from 60,000-65,000ozpa up to 95,000ozpa.

Sugar Zone has probable reserves of 3.9 million tonnes at 7.1g/t for about 890,000oz, plus additional resources.

It is targeting life-of-mine AISC of US$845/oz at the lower annual production rate. The company continues to be frugal with cost information while it establishes the commercial credentials of the operation.