Miners working at porphyry copper and gold deposits should be aware that the deeper a deposit is, the more copper there will be, while gold-rich deposits are closer to the surface. This, according to a study published in Nature Communications.
In the article, Massimo Chiaradia, a researcher from the University of Geneva, presented his findings after investigating how the metals are accumulated over the time duration of a mineralizing event in porphyry deposits and finding a correlation between the amounts of copper and gold extracted from the deposits.
Not only did Chiaradia discover that the depth of the deposits influences the quantity of metals produced but also that over 95% of the gold is lost to the atmosphere through volcanic emissions.
“A copper deposit can contain from one to 150 million tonnes, while the quantity of gold varies from 10 tonnes to 2,500 tonnes per deposit,” the researcher said in a media statement.
Chiaradia used a range of statistical models to analyse two hypotheses: either the magmatic fluids have varying amounts of metal from the outset, or the fluids are identical but it is the effectiveness of the precipitation of the metals that influences the quantity of copper and gold.
“I quickly saw that the first hypothesis wasn’t right and that the answer lays with precipitation but with differences for gold and copper-related to the duration of mineralisation,” he explained. “The longer the mineralisation time, the richer the deposit will be in copper. And for the mineralisation to be as long as possible, the deposit must be deep – 3 kilometres from the surface – to guarantee a certain degree of insulation and a long magma life.”
The geologist observed that less than 1% of the gold is captured in the ores in the deep copper-rich deposits. On the other hand, in deposits located at a depth of up to 3 kilometres, the rate climbs to 5%.
Chiaradia said that although gold escapes easily in volcanic emissions, it is retained more in shallow deposits where separation takes place between the liquid and the vapour, which helps its precipitation.
“In the deeper deposits, however, liquid and vapour form only a single fluid phase, which precipitates the copper quickly and makes the gold leak into the atmosphere as the fluid rises to the surface,” the expert said.
Lucara Diamond Corp. (TSX:LUC) has struck a deal with the luxury house Louis Vuitton to cut and polish the world’s largest uncut diamond, and second largest ever found.
Under the deal, Louis Vuitton and HB Company, a diamond manufacturer in Antwerp, will cut and polish the 1,758-carat Sewelo diamond.
Lucara isn’t saying how much the deal will be worth. The company will retain 50% of the diamonds that are cut from the massive Sewelo.
The Sewelo was unearthed at Lucara’s Karowe mine in Botswana in April 2019, bumping a previous find – the 1,109-carat Lesedi La Rona – to third place.
When Lucara unearthed the Lesedi La Rona in 2015, it was the second largest diamond ever recovered. But in April 2019, the Sewelo became the second largest diamond ever unearthed.
The Sewelo is the world’s largest uncut diamond.
In 2017, Lucara sold the Lesedi La Rona diamond to Graff Diamonds for $53 million.
(This article first appeared in Business in Vancouver)
Vancouver-based American Battery Metals Corp. (CSE: ABC) has entered into a non-binding letter of intent to acquire Bayshore Minerals Inc., a private exploration and development company that owns the Elk gold project located in south-central British Columbia.
The Elk project is host to an NI 43-101 compliant resource estimate comprising 442,600 ounces of gold in the measured and indicated categories as well as 88,000 ounces of gold in the inferred category.
The property is located within the Similkameen mining division and consists of 27 contiguous mineral claims and one mining lease covering 16,566 hectares.
Currently the Elk project has a ‘small mines’ permit under the care and maintenance provision, has bonding in place for an exploration permit, and an effluent discharge permit. Bayshore has been focused on reactivating and expanding the scope of the mine permit for a much larger operation.
“The Elk gold project is known as a high-grade gold gold deposit that has been the subject of significant expenditures including over 125,000 metres of drilling property wide, over 110,00 metres of which forms the basis confirming the project’s high-grade resource estimate,” Jeremy Poirier, president and CEO of American Battery Metals commented.
“Given the extensive exploration and development to date, we see the potential for near-term production coincident with the recent macro events which supports an improving gold market.”
Under the terms of the LOI, American Battery Metals would issue approximately 27 million shares in exchange for all the issued and outstanding shares of Bayshore. Completion of the transaction is expected in the first quarter.
Shares of American Battery Metals surged by 16% on the CSE at midday Friday. The company’s market capitalization stands at C$10.81 million.
Australian rare earths miner Lynas Corp (ASX: LYC) said Friday that three individuals in Malaysia had filed a lawsuit challenging the government’s decision to renew the company’s operating licence last year.
The miner, the world’s only major producer of rare earths outside China, isn’t the only one being sued. Other targeted people include the Prime Minister of Malaysia, 27 other Ministers and Cabinet members, the Government of Malaysia and the Atomic Energy Licensing Board, Lynas said.
The court case questions the processes followed by the government in reaching its August decision to allow the miner to continue operating in the country, under certain conditions, , including identifying a Malaysia-approved site for a permanent disposal of the waste Lynas generates at its plant.
The Sydney-based miner agreed to start extracting low-level radioactivity from the ore mined at its Mt. Weld operation, before shipping it to Malaysia for final treatment.
The cracking and leaching plant, to be built this year in Kalgoorie, Australia, will perform the first step of concentrate processing in 2021. The facility is expected to be completed in late 2022 or early 2023.
Lynas said at the time it planned to explore opportunities for the next stage of rare earth processing (upstream solvent extraction) in Western Australia.
The company, which controls just over 10% of the global rare earths market, has also revealed plans to build a separation plant in the United States.
The facility would be the world’s only large-scale producer of separated medium and heavy rare earth products outside of China, which currently accounts for 70% of global production. Beijing also controls 90% of a $4 billion global market for materials used in magnets and motors that power phones, wind turbines, electric vehicles and military devices.
The series of announcement came after increased opposition and scrutiny to its Lynas Advance Material Plant (LAMP) in Malaysia. Environmental groups and local residents feared about the impact the low-level radioactive waste the refinery generates could have on the health of those living nearby, and to the environment.
Lynas said its Malaysian subsidiary and LAMP have been the subject of four independent scientific reviews, including two probes by the International Atomic Energy (IAEA) and a report by the current Pakatan Harapan Government’s independent scientific committee. All of them, it said, have concluded that Lynas Malaysia is low risk and compliant with the country’s laws and regulations in effect.
The company will face the fresh case against it in Jan. 21, it said.
B2Gold (TSX: BTO) (NYSE AMERICAN: BTG) reported a record annual consolidated gold production of 969,495 ounces in 2019, including 118,379 ounces from discontinued operations.
The 2019 figures exceeded the upper end of the company’s guidance, which was set between 935,000 and 975,000 ounces. The numbers also mark the eleventh consecutive year that B2Gold achieved record annual consolidated gold production.
In a press release, the Canadian miner explained that this success can be attributed to the high output of the Fekola mine in Mali, the Masbate mine in the Philippines and Otjikoto mine in Namibia, which all exceeded the upper end of their 2019 production guidance.
“In December 2019, the Fekola mine exceeded one million ounces of gold production (since the commencement of ore processing began in September 2017), achieving this milestone a full year ahead of the original production schedule,” the media brief states.
B2Gold also reported annual consolidated gold revenues from continuing operations of $1.15 billion on sales of 827,800 ounces, and annual consolidated gold revenues of $1.31 billion on sales of 943,465 ounces, including gold sales from discontinued operations.
For 2020, the company said it expects to continue the upward trend with its production guidance set between 1,000,000 and 1,055,000 ounces of gold, including attributable ounces of between 45,000 and 50,000 from Calibre Mining.
Rio Tinto’s (ASX, LON, NYSE: RIO) iconic Argyle mine in remote Western Australia, the world’s biggest and the main global source of high-quality pink diamonds, will close in the fourth quarter this year, potentially pushing prices up and spurring exploration.
The planned closure, the company said, will impact its total diamond output for the year. Rio now expects to produce between 12 and 14 million tonnes of rough diamonds in 2020, down from the 17 million tonnes it churned out last year.
The impact on Rio’s balance sheet, however, are expected to be minimal. Diamonds bring in only about 2% of earnings, while iron ore — the company’s main commodity — accounts for almost 60%.
Pink diamonds, already rare, are about to get scarcer as Argyle accounts for 90% of worldwide production of the coloured precious rock. The mine has yielded more than 865 million carats of rough diamonds since it opened in 1983 and, so far, there hasn’t been major discoveries or projects capable of measure up to Argyle in terms of production.
At its peak, the mine produced 40% of world diamond output by volume. It still accounts for all of Australia’s diamond production.
Rio Tinto estimates Argyle’s direct contribution to the East Kimberley in roughly 6% of the region’s gross regional product.
Analysts and auctioneers alike expect prices for the unique diamonds to go up. Pink stones have already been fetching record prices in the past few months and the closure of their mine source could see that trend strengthen.
In 2018, the 18.96-carat Pink Legacy sold for $50 million at Christie’s auction house, breaking the world record for price paid per carat for a pink diamond at auction.
At Sotheby’s Hong Kong October sale, one of the star pieces — described as an “exquisite 10.64-carat vivid purplish pink diamond” — sold for just under $20 million. Rio Tinto’s own data show that the prices for their Argyle pink diamonds have jumped by 500% since 2000.
The mining giant said the decommissioning and dismantling the mine would take five year, after which it would monitor the site for a period to be defined.