Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr
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DIAMOND MINING SEPTEMBER 2017 • E&MJ; 65 www.e-mj.com Ore processing began in July 2016, two years after construc- tion began. The mine produced 2 million mt of open-pit ore during the year, while recovering nearly 450,000 ct. Four kimberlite pipes host the initial resource of 22.3 million ct. Open-pit mining from the combined Renard 2 and 3 pipes will continue until next year, and from the Renard 65 pipe until 2029. Underground production will be from the Renard 2, 3 and 4 pipes, with Renard 2 holding the bulk of the underground resources. Stor- noway expects to produce 1.7 million ct this year, while mining 4.4 million mt from the open pits and 500,000 mt from underground. And the search for Canadian diamonds is by far from over, with a number of junior companies at work. These include Per- egrine Diamonds with its Chidliak open-pit project on Baffin Is- land, Dunnedin Ventures (the Kahuna project in Nunavut) and Kennady Diamonds, which has the Kennady North landholding near Gahcho Kué. In June, Rio Tinto took a three-year exploration option on Shore Gold's long-standing Star-Orion South project in the Fort à la Corne area of central Saskatchewan, with a $18.5 million commitment to win a 60% stake in a future joint Big Stones Sparkle A feature of the period since E&MJ;'s last major review has been the number of large rough diamonds that have been unearthed — an achievement in which some smaller producers can claim equal credit with the industry's long-standing majors. And they have not been slow in advertising their successes either, pre- sumably working on the premise that successful, well-publicized sales of large stones will do their share price no harm at all. For example, Gem Diamonds discovered a 314-ct stone at its Letšeng mine in Lesotho in May 2015, and two months later had a 357-ct diamond in its safe — later sold for $19.3 mil- lion. Also in 2015, Lucara Diamond Corp. discovered the 342-ct "Queen of Kalahari" at its Karowe mine in Botswana, with the US$20.6 million stone subsequently being transformed into a suite of six pieces of jewelry containing 23 flawless cut diamonds. Not all sales of large diamonds are successful, though, as was shown in May this year when the government of Sierra Le- one tried to garner interest for a 709-ct rough stone that had been found two months earlier. The top bid of US$7.8 million was rejected as insufficient, according to a Reuters report, al- though the price offered would suggest that the diamond was not of a quality to match its size. Lucara was also disappointed when the 1,109-ct "Lesedi La Rona," the second-largest gem-quality rough diamond ever dis- covered, failed to meet its expected price of at least US$70 mil- lion in June last year, although the company gained some rec- ompense as its 813-ct "The Constellation" had sold for US$63 million a month before that. Even Rio Tinto has been in on the act, with the 187.7-ct "Diavik Foxfire" discovered during 2015. By all accounts the stone should have been rejected and sent to waste, but its elon- gated shape allowed it pass through the scalping screen. The sale price was not disclosed. And not to be outdone, Alrosa reported the recovery in July of a 75-ct stone and one weighing almost 110 ct at its Mirny operations in Russia. In 2016, the company found a 207-ct di- amond at its Zarnitsa mine, the largest recovered since open-pit mining started there in 1999.