Tag Archives: Thor Mining

OZ Minerals backs in-situ copper-gold recovery project

OZ Minerals has committed funds to support in-situ recovery (ISR) research at the Kapunda copper-gold ISR project in South Australia, putting the project owners closer to outlining the potential economic extraction of copper resources via ISR.

Kapunda is being steered by EnviroCopper Ltd, which, itself, has a joint venture in place with tenement holder Terramin to earn up to a 75% interest in the mineral rights over metals which may be recovered via ISR.

As part of the agreement with OZ Minerals, the company has committed to A$2.5 million ($1.75 million) over 18 months to support ISR research at the Kapunda project, according to Thor Mining, which as a 30% interest in EnviroCopper.

This funding will continue studies into the potential economic extraction of copper resources via ISR, with collaboration between the two companies kicking off this quarter.

EnviroCopper plans to develop a Mining Lease application for the Kapunda project, which, from 2018-2021, was subject to extensive research into solving existing knowledge gaps in the ISR industry. Funded by a Cooperative Research Centres (CRC) Program Grant from the Dept of Industry, Innovation and Science to the total value of A$6 million (cash and in-kind), EnviroCopper partnered with industry, CSIRO and University of Adelaide to carry out this work.

The key objective was to research the core values of environmental, social and economic impacts of ISR mining, a proven method of metal recovery that has been used for over 50 years and, with recent technological improvements, is being considered for the recovery of metals like gold and copper from mineral deposits that can not be mined by conventional methods.

Kapunda is a town with a rich mining history, growing from Australia’s first ever commercial copper mine in the 1840s. Even though the mine ceased production in the early 1900s, successive mining companies have looked at recovering the remaining copper over time, but, due to the proximity to town, conventional mining would not be possible. ISR mining is a possible solution to extracting this remaining copper in an environmentally- and community-sensitive manner.

Leaching tests move Thor a step closer to ISR copper solution at Kapunda

Thor Mining has made a metallurgical test work breakthrough at the Kapunda copper project in South Australia, indicating in-situ recovery (ISR) may be a viable extraction solution at the historic mine.

The results show two days of bottle roll leach testing using a biodegradable amino acid as a lixiviant can recover up to 78% of copper, Thor said.

The company has a right to earn up to 60% of Kapunda by funding test work and feasibility study activities on the project over the next two years and, in February, Thor announced an initial inferred resource of 119,000 t of copper, grading 0.25% Cu, as part of this.

Kapunda is a town built up around Australia’s copper mining history and lays claim to not only being the first established profitably operating copper mine but also being the saviour of South Australia’s financial woes in the 1840s.

The ISR resource estimate was built on the back of historic drilling data taken from 1965 through to 2008 at Kapunda.

A series of bottle roll tests over seven days was conducted on four drill core samples by the company’s cooperative research centre partner, CSIRO. This work is part of a A$2.85 million ($2.10 million) grant from the Australian Commonwealth Government for the Kapunda In-Situ copper and gold recovery trial.

The Deep core sample (0.27% Cu) produced the best results, coming back with recovery of 78.48% after just one day, while the Top sample, which graded 0.103% Cu, had a 60% recovery after seven days.

Interestingly, the lixiviant used was glycine, an amino acid typically used in food and pharmaceutical industries.

Mick Billing, Executive Chairman of Thor, said while laboratory conditions were not a full simulation of field processing, these were still positive results.

“The success with glycine, a very benign substance, is an important step forward. Other lixiviants are also being trialled, and we look forward to these results when available,” he said.

If Thor is successful in proving Kapunda ore can be extracted by such means, it is likely to lead to other existing deposits becoming potential ISR candidates.