Broken Hill is back, baby!
It’s undoubtedly the most famous of all Australian mining areas and one of the world’s all-time great deposits of metals – especially silver, lead and zinc. “The Line of Lode” was where the best deposits of these minerals were found at The Hill and was known to miners all over the world.
Based on its riches the world’s biggest miner, BHP started there as did South32. OZ Minerals can trace some its parentage back as well. Rio Tinto’s family tree has strong links to the ‘Line of Lode’ through Consolidated Zinc which came Conzinc Rio Tinto (CRA) in 1962 and then Rio Tinto in 1995.
Over the decades the mines have waxed and waned as the rich ore was depleted and mining became too expensive. BHP went off to iron and steel and then fame and fortune in copper and iron ore. Likewise Rio Tinto which grabbed CRA was based on the famous Rio Tinto copper mining area of Spain.
Perilya Ltd still mines at Broken Hill after it was taken over by Chinese group, Zhongjin Lingnan (China’s third largest zinc processor) in 2013.
But after years in the doldrums, exploration activity has stepped up with some interesting discoveries revealed or hinted at.
The most intriguing is ASX-listed Cobalt Blue’s discovery of cobalt – one of the few important metals not found in any great quantity in Australia but one that is now vital in battery technology and renewable energy sources.
Last week saw Cobalt Blue’s project – valued at $560 million – granted major project status by the Federal Government which will ensure the project is built and can start operating without delay. The project is around 25 kilometres southwest of Broken Hill.
The deposit has been known about for years and has gradually been worked up to a viable level that has coincided with the boom in renewables and batteries.
The project will produce 16,700 tonnes annually of high purity cobalt sulphate, which will be used in the manufacture of lithium-ion batteries.
This production will see downstream processing capacity built. The project will also produce 300,000 tonnes of elemental sulphur, which will reduce Australia’s dependence on imports for fertiliser production.
The project is expected to deliver 450 jobs during its two-year construction phase and 410 jobs each year during 17 years of full production.
A pilot plant has already produced samples for shipping to battery precursor manufacturers across the country and the world.
Chalice Mining’s mega large Gonneville prospect northeast of Perth is estimated to hold 55,000 tonnes of cobalt at the moment, but that is due to be upgraded in May when a new resource estimate will be produced based on intensive drilling across the area.
In its December quarter report on January 31, Cobalt Blue (COB) said, “During the December quarter COB produced its first cobalt sulphate samples and these were subsequently delivered to partners. The production and dispatch of the cobalt sulphate samples represents an important milestone for the BHCP
“The delivery of the cobalt sulphate samples also marked the formal end of Pilot Plant operations. Planning and procurement works are under way for the Demonstration Plant, with supporting bulk extraction and field work planned over the March quarter.
“COB received positive feedback from the samples dispatched to partners over Q3 2021. All samples were within commercial tolerances with feedback centred on customising products to individual customers. A number of the partners that received the Pilot Plant samples are now shortlisted for large sample batches (up to 100 kg) to be supplied from the Demonstration Plant activities in 2022. These large samples are required for acceptance testing and production of laboratory scale batteries.
“COB expects to update the market with an overall commercial cobalt sulphate specification in due course. Product specifications will be discussed with cobalt sample partners in the first instance and COB expects iterative development of specifications to match individual battery maker needs precisely.”
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And then there is the Impact Minerals project (now a joint venture with IGO) east of Broken Hill which has made what appears to be a headline-grabbing discovery involving PGE minerals, as well as gold, copper and silver.
Impact’s Broken Hill nickel/copper/PGE project is located 20 km east of the Broken Hill and “consists of 100% owned seven Exploration Licences covering 816 sq km in the south east part of the richly mineralised Curnamona Province,” according to Impact.
“The project area contains several tens of strike kilometres of mafic-ultramafic sills, dykes and stocks that contain gossans and fresh outcrops with very high-grade PGE’s, nickel, copper, gold and silver mineralisation.”
Impact has already reported results from diamond drilling that indicate solid intersections of copper, nickel, PGE products gold and silver.
In a statement earlier this month IGO and Impact revealed that “A large strong EM (electromagnetic0 conductor about 420 metres by 85 metres in dimension and buried at a depth of about 350 metres below surface has been identified in the extensive EM survey in progress at the Broken Hill project in joint venture with IGO.
“The conductor is about 1,000 metres along trend from previous drill hole PSD002 which intersected massive sulphide with similar electrical conductance to the new conductor and returned: 0.6 metres at 11.5 g/t (grams to the tonne) platinum, 25.6 g/t palladium, 1.4 g/t gold, 7.6% copper, 7.4% nickel and 44.3 g/t silver from 57.1 metres down hole.”
“The conductor lies within a major shear zone interpreted to be a possible feeder zone for the extensively mineralised nine-kilometre long Moorkai Trend. Such feeder zones are prime targets for massive sulphide mineralisation,” according to Impact’s statement on Thursday.
“The new EM conductor is considered a prospective target for massive nickel sulphide mineralisation due to its strong conductance and geometry, as well as its proximity to a large (possible feeder) structure and previous massive sulphide intersections.
“It is hoped that further conductors will be identified as the survey, which is expected to take about three months to complete, progresses across the Impact-IGO joint venture tenements.
“IGO has indicated it will wait until the end of the survey to assess any conductors identified for further work,” the statement added with Impact saying the survey will take another three months to complete.
Impact Minerals’ Managing Director Dr Mike Jones said “It is fantastic to have made an early breakthrough on the major EM survey at Broken Hill with our joint venture partner IGO. The EM conductor lies within a major structure that may have been a feeder zone for the entire Moorkai Trend and in an area with no previous exploration.
“It is a very compelling target, and we look forward to receiving more results from the EM survey as it progresses.”
Under the terms of the deal announced last November IGO can earn an initial 51% in the project area by spending $6-million on exploration over a four-year period, which would establish an unincorporated joint venture (JV) between the two companies.
IGO can spend a further $12-million over the subsequent four years, to earn a 75% interest in the project.
