Precious metals miner Great Panther Silver Ltd (TSX:GPR: NYSE:GPL) updated on its Coricancha gold-silver-lead-zinc-copper in Peru, where it is carrying out a bulk sample programme (BSP).
The work will process around 6,000 tonnes of material and is expected to be completed in the first quarter of 2019. The aim is to validate the key mine and process plant operating parameters used in the preliminary economic assessment (PEA), which was announced in May this year. Following the completion of the work, Great Panther expects to make a decision in early 2019 on whether to begin or not to re-start the project.
READ: Great Panther Silver pushing ahead with bulk sample programme at Peru project; posts second-quarter results
The trial mining stope has, so far, reached 160 metres of access, the firm said. The development has reached mineralisation at the Constancia vein, which has shown a 2.05-metre vein width grading 151g/t (grams per ton) silver, 6.04 g/t gold, 2.94% lead, 1.06% zinc, and 0.12% copper. Other advances are the successful test of the crusher, and that the refurbishment of the concentrator is well advanced. In May, the PEA announced showed robust numbers and low capital costs, the firm said.
It assumed using standard cut-and-fill and resue mining techniques providing ore to support a target annual throughput rate of 550 tonnes per day (tpd) to the mill.
Using base case metal prices, including gold at US$1,300 per ounce and silver at US$16.50 an ounce, Great Panther said the mine was estimated to generate an after-tax net present value (NPV) of US$16.6mln and an after-tax internal rate of return (IRR) of 81%.
Operating costs were pegged at US$55.71 per tonne mining, US$68.83 per tonne processing, and US$23.52 per tonne for general and administration, for a total cost of US$148.06 per tonne.
Cash costs were estimated to be US$14.06 per payable silver ounce or US$70 per payable gold ounce over the life of the mine.
All-in sustaining costs (AISC) were estimated by the report to be US$2.20 per payable silver ounce, or US$547 per payable gold ounce, over the life of the mine.