THE map above shows 2010’s top 10 lead, zinc, copper, gold, nickel and silver producing mines – an important reminder of the significance of Australia mines globally. In fact, there are eight Australian mines
shown, and they take 11 of the 60 top 10 slots. The Century, Cannington and Mt Isa mines were all top 10 producers for two different commodities.
As we enter the latter half of 2011, we can review half-yearly (HY) production results and see which mines are on track to achieve 2010 levels of production. Each of the gold, nickel, copper, silver and zinc top 10 mines have delivered HY results ranging between 95 and 101 per cent of 2010 levels.
There are really three international examples of outstanding growth across those commodities: the US-based Cortez gold mine; the Voisey’s Bay nickel mine in Canada; and Goldcorp’s Penasquito mine in
Cortez has the biggest rate of growth: its production in the second quarter of 2011 was 419,000 ounces, one of the largest recorded. The area of Nevada where the mine operates looks set to continue to grow as Barrick Gold recently announced that it had made two significant gold discoveries on its 100 per cent-owned property there. The two discoveries, Red Hill and Goldrush, are on highly prospective ground six kilometres southeast of Barrick’s existing Cortez Hills open pit mine, which began production in early 2010, and 24km southeast of its Pipeline mine. The new discoveries are geologically similar in style to Barrick’s Cortez Hills and Goldstrike mines. The Voisey’s Bay mine, owned by Vale subsidiary Vale Inco, is expected to add an additional 50 per cent to its production by the close of 2011. This is despite a furnace stoppage and maintenance work that Vale undertook at a number of its nickel operations, including Voisey’s Bay, during the second quarter of 2011. The Penasquito mine is the big growth story in global silver production for 2011.
The mine continued its ramping up of metal production in the second quarter, with ore grades and recoveries of all metals increasing as mining progressed into the heart of the mine’s sulphide ore deposit. Production in 2011 will likely be at least 50 per cent higher than last year.
For lead, the overall HY results for international miners of the commodity are averaging only 76 per cent of last year’s levels. Looking at production figures mine by mine is a reminder of the circumstances that
can befall even the most significant mines, particularly where lead is involved. The most dramatically impacted production of all the lead mines is that of the Viburnum mine in Missouri, US. The mine’s owner, Doe Run Resources of St Louis, North America’s largest lead producer, has had a ruling against it and has consequently agreed to spend about $65 million to correct violations of several environmental laws at
10 of its lead mining, milling and smelting facilities in southeast Missouri. The ruling – announced in October 2010 by the Justice Department, the Environmental Protection Agency (EPA) and the Missouri Department of Natural Resources – has resulted in a production halt at the mine since it was announced. The settlement requires the company to pay a $7 million civil penalty and, consequently, production from Viburnim has effectively been zero so far in 2011. The consequences of environmental impacts are also evident closer to home, with Canadian miner Ivernia placing its Magellan mine, northeast of Perth, on care and maintenance following a stop/start 2011. An order was issued by WA Environment
minister Bill Marmion on January 3 with respect to cessation of transportation of lead carbonate concentrate from the mine and Ivernia subsidiary Magellan Metals stopped operations at the mine from January 5 to February 23. The order was consequently lifted and a ramp up of operations began but, following the detection of lead-bearing mud on a shipping container on April 7, thecompany announced that it had placed the mine on care and maintenance. Still locally, but looking to the east coast, there are reminders of the impact of severe weather in production results. Of note is the impact of the significant rainfall in
Queensland in January, particularly on Oz Minerals’ Century mine’s March quarter mine and mill production results. Lead in concentrate production was 3960 tonnes: 42 per cent lower than the previous quarter due to the impact of the wet season.