More to explore, discover and develop in Tasmania
We look at Tasmania where almost half of the State's export income comes from mining.
For its size, Tasmania is one of the most mineral-rich areas in the world. It has a remarkable diversity of minerals and even with the global financial crisis its mining sector has experienced strong rates of production in the past year.
Tasmania's mining and mineral processing sector was a pillar of the state's economy during 2008-09. Mineral products worth $1.56 billion, representing 44.8 per cent of the state's export income, were exported. These consisted of aluminium, copper, gold, lead, magnetite, nickel, scheelite, silver, tin, zinc and ferro-alloys, as well as metallurgical grade limestone, ultra-high purity silica flour, dolomite, construction aggregate and minor amounts of coal.
Exploration activity continues to find new deposits of all previously known minerals as well as deposits of previously undiscovered mineral associations.
Major mining and smelting operations
There are seven substantial operating mines in Tasmania, including long-term producers Mount Lyell (copper, gold, silver), Rosebery (zinc, lead, gold, copper and silver) and Savage River (magnetite), which also converts magnetite into iron ore pellets at Port Latta.
The Henty and Beaconsfield gold mines began producing in the 1990s, the latter after a hiatus of 85 years, and the Mt Bischoff and Renison Bell tin mines reopened during 2008.
Smaller mines at Kara (magnetite, scheelite) and at Hellyer-Que River (zinc, lead, gold, copper and silver) are in expansion phases. However, a new mine for nickel, at Avebury, is on care and maintenance.
Ultra-high purity silica flour, used mostly in the manufacture of LCD panels, is mined at Corinna, coal is produced from three localities near Fingal, limestone is mined and cement manufactured at Railton and metallurgical grade limestone is quarried near Beaconsfield and at Mole Creek. Dolomite is mined at Smithton.
Nyrstar operates a zinc smelter at Hobart, while at Bell Bay Rio Tinto Alcan operates an aluminium smelter and TEMCO operates an electro-metallurgical smelter to produce ferro-manganese and silicon-manganese.
Mining developments
Bendigo Mining has announced completion of the purchase of the Henty mine from Barrick Gold Corp. Bendigo will increase exploration and aim to extend the life of the mine beyond the closure at the end of 2009 planned by Barrick. Barrick now owns 2.2 per cent of Bendigo.
The Chinese-owned Minerals and Metals Group (MMG) has announced that development of the $25 million raise bore at the Rosebery mine will proceed and a $1.6 million in-mine exploration project will resume. The company is buoyed by recent successes, with an increase in resources announced recently indicating the potential to extend mine life beyond 15 years.
MMG also recently acquired the Avebury nickel mine, west of Zeehan, which is on care and maintenance but is intended to produce 7500 to 8500 tonnes of nickel in concentrate from 900,000 tonnes of ore a year. The company has an off-take agreement with the Jinchuan Nickel Group.
A merger of Grange Resources and Australian Bulk Minerals was completed in January 2009. The new company is now Australia's largest producer and exporter of high-value magnetite iron products.
Shagang Mining Australia, which is owned by the Chinese Shagang Group, along with the other shareholders in ABM hold 73.9 per cent of the shares in the merged group. This merger has paved the way for a $150 million project to extend the open cut mine and upgrade production equipment and the concentrate plant.
Options are being investigated for increasing the production rate of iron ore from 2.5 million tonnes to 3 million tonnes a year and eventually 3.5 million tonnes a year. Bass Metals has started open-cut mining of high-grade zinc-lead-silver-gold ore at Que River as the initial phase of a five-year project.
Metals X (MLX) has signed a heads of agreement with the Yunnan Tin Group (Holding) Company (YTG) to sell up to 60 per cent of the Bluestone Mines Tasmania Renison Bell tin mine. MLX will form an unincorporated joint venture with YTG to continue to develop its Tasmanian tin projects.
MLX has reopened both the Mount Bischoff and Renison Bell tin mines. For the first time copper will be a significant co-product from Renison Bell. MLX expects to complete an engineering and feasibility study into constructing a plant to treat the Renison Bell tailings to recover tin and copper in the near future. This project will open up the possibility of treatment of the complex stannite-bearing cassiterite-sulfide ores that are known in western Tasmania and open up further exploration opportunities.
King Island Scheelite (KIS) has announced a financing and partial off-take agreement with the Hunan Nonferrous Metals Corp. KIS has a resource of 13.4 million tonnes of 0.64 per cent tungsten trioxide in the Dolphin ore body at Grassy and has completed a feasibility study for an initial 10-year project in which 6.8 million tonnes of ore would be mined to produce an average of 3000 tonnes of tungsten trioxide a year. It has all approvals in place for the start of mining.
Promising results from investigations of scheelite recovery using whole ore flotation have been reported and the company is also investigating the potential recovery of tungsten from old tailings.
Gladstone Tin is planning to resume alluvial tin production at two centres, Scotia and Endurance, in North East Tasmania, with possible recovery of gem sapphire and spinel as significant co-products.
Proto Resources and Investments has signed a joint venture with Metals Finance Corp with a view to producing 4000 tonnes of contained nickel a year in a high-grade salt from the Beaconsfield laterite.
Maydena Sands is investigating a silica mining project at Maydena in southeast Tasmania.
Exploration
Mineral exploration in Tasmania slowed during 2008-09 as a result of the global downturn but has started to recover. A number of factors are contributing to this growth, including:
- an increase in commodity prices, especially for commodities such as copper, tungsten and tin, with which Tasmania is well endowed;
- production of high-quality, globally competitive geoscientific data including the 3-D geological model and prospectivity analysis of Tasmania;
- a clear and consistent regulatory regime for both exploration and mining;
- a strong promotional program; and
- no native title issues.
A trend over the past five years is the number of new companies achieving public listing on the ASX or AIM, largely or totally on the basis on Tasmanian exploration assets. This, together with a good mix of other mid-sized and junior companies exploring in the state, provides a new dynamic environment to the Tasmanian exploration scene.
Metals X has announced that in-mine exploration at Renison Bell continues to yield good results, including intersections of 9.43m at 3.7 per cent tin and 9.73m at 3.82 per cent tin in the Federal zone. During the 2008-09 year, total resources of tin ore increased from 4.4 million tonnes at 2.01 per cent tin to 7.2 million tonnes at 1.82 per cent tin.
There was a 65 per cent increase in total resources in the Renison Bell mine in 2008-09 to 7.234 million tonnes and a 49 per cent increase in contained tin to 131 660 tonnes, reflecting the success of the in-mine exploration program.
Bass Metals has reported an updated combined mineral resource (indicated and inferred) for the Fossey Zone at Hellyer of 800,000 tonnes grading 9.9 per cent zinc, 5.8 per cent lead, 0.4 per cent copper, 137g/t silver and 2.5g/t gold. Metal recoveries in test work are 93 per cent for zinc and 87 per cent for lead. Bass has identified five targets near Hellyer for exploration drilling. The company has also announced a new resource figure for the Que River deposits and inferred and indicated resources at Mount Charter.
Venture Minerals is drilling the Mount Lindsay magnetite-tin skarn deposit near Renison Bell and has established Inferred Resource of 30 million tonnes of 33 per cent iron ore as magnetite, 23 million tonnes of 0.2 per cent tin and 5.7 million tonnes of 0.3 per cent tungsten trioxide as scheelite, with the tin and tungsten resources within or immediately adjacent to, the magnetite resource.
Venture has also released results of a scoping study conducted on mining magnetite, tin and tungsten at the deposit. At a mining rate of 4.4Mtpa, the project would have a life of more than seven years. The company has recently announced assays of 66 per cent iron ore from each of two rock chip samples from the Rocky River South prospect, 9km west of the Stanley River deposit, which is being investigated as a source of direct shipping iron ore.
Frontier Resources has announced an inferred resource at the Stormont deposit at Moina of 91,400t at 4.57g/t Au, 0.30 per cent Bi and 3.52g/t Ag. Resources at the nearby Narrawa prospect have been upgraded to 209,330t at 2.1g/t Au, 19.5g/t Ag, 1.32 per cent Pb and 1.12 per cent Zn of which 78 per cent is in the Indicated category at similar grade. Resource extensions are possible at both deposits.
Stellar Resources has intersected potentially high tonnage, low grade, copper mineralisation in 10 holes at the Alpine prospect, 10 kilometres south of Corinna, and Stonehenge Metals has defined a silver-lead-zinc lode at the Sunshine prospect near Zeehan.
Numerous other drilling programs are in progress and major exploration projects are underway at operating mines.
