The price of copper revives old deposits
US Copper, formerly known as Crown Mining, has announced plans to undertake 2,100 to 3,000 meters of core drilling at the Superior deposit. This is one of three deposits in the 100% owned Moonlight-Superior copper project in Plumas County, previously drilled in the 1960s by Placer Amex.
“We intend to bring our Moonlight-Superior project to production as quickly as possible, and the current drilling program is the first step,” said President and CEO Stephen Dunn in a June 1 press release.
“A recovery in copper prices and the global transition to sustainable energy through electrification with alternatives to non-fossil fuels has created an ideal environment for the development of new coppers in the United States,” he said. .
The district contains significant copper and silver sulphide and copper oxide resources at three deposits – Moonlight, Superior and Engels – and several partially tested and untested exploration targets.
The Superior and Engels mines operated from around 1915 to 1930, producing over 161 million pounds of copper from over four million tonnes of rock containing 2.2% copper with credits of silver and gold .
Former operator Placer Amex, which later morphed into Placer US, had calculated a historic resource of more than four billion pounds of copper. They sold the project to focus on their gold portfolio. Several junior mining companies then owned the project from 1994 to 2011, which undertook a series of incremental exploration campaigns.
The current compliant resource estimate implies a more modest grade of 1.3 billion pounds of copper in the grades shown and inferred at an average grade of 0.25% copper.
The 2021 drilling program is designed to define a high grade start-up pit, expand and upgrade resources, and establish silver and gold credits.
A preliminary economic assessment from 2018 calculated an after-tax net present value at Moonlight of $ 179 million at $ 3.15 per pound of copper price.
Meanwhile, Sweden-based Copperstone Resources said on Friday it opened this week and entered the Viscaria copper mine for the first time since it closed in 1996.
Historically, the Viscaria mine has produced 12.5 million tonnes of ore grading 2.3% copper. The company believes it has “excellent potential” to become a producing mine again.
For a quarter of a century, a moraine layer 50 meters long and 6 meters thick covered the entrance to the mine. Nevertheless, the company believes the time has come to inspect the condition of the groundwater, rock mechanics and geology in more detail.
The company expects to receive confirmation that the previous remediation work has been successful and that the main infrastructure is in good condition as it operates to restart production from the high-grade operation.
Although the work is part of a feasibility study, CEO Anna Tyni said: “It sounds like a historic day for us who grew up with the mines in Kiruna.”
“The test drilling and environmental surveys that we were able to carry out on the surface met our expectations and we are now taking the next step and investing in other studies inside the old mine,” said Tyni said.
Further studies of groundwater quality and level are needed for the environmental permit application, which the company hopes to submit to the Land and Environmental Court by the end of the year.
Viscaria is home to several mineralized domains, including Zone D, which also contains significant volumes of iron ore. Given the recent record price for iron ore, this prompts the company to start mining as soon as possible.
A 2020 resource statement estimates that the project holds 58.97 million tonnes for 699,400 tonnes of copper at a grade of 1.2%. The project also has five million tonnes of iron ore at an average grade of 28.44%.
The Viscaria project area is located approximately five kilometers west of the city of Kiruna. It is close to major infrastructure, including the E10 motorway, the Luleå-Kiruna-Narvik railway and the established hydroelectric network.