MMG Rosebery 14 July 2015

Transcription

1 MMG Rosebery 14 July 2015

2 History of Rosebery Tom McDonald discovered alluvial gold with boulders of zinc-lead sulphide. Rosebery and Hercules Mines purchased by the Electrolytic Zinc Company of Australasia Limited. (EZ) Construction of Rosebery Mill begins Production started in February Mill capacity was 15 tonnes/hour Mill capacity was 30 tonnes/hour Murchison Highway completed. Breakthrough of surface decline allowing trucking of ore to surface. Transition from Pasminco to Zinifex Ltd., becoming one of Australia s leading companies in mining and producing zinc, lead, copper, gold & silver. Zinifex Ltd and Oxiana merged into OZ Minerals. MMG Minerals & Metals Group. 75 years of continuous mining and milling at Rosebery. 2

3 Overview Location: Ownership: Tasmania, Australia 100% MMG Mine: Underground (sublevel open stope Transverse, Longitudinal and slashing stoping) Throughput: 0.95 Mtpa, mine, crush, grind, float Product: Zinc concentrate, Lead concentrate, Copper concentrate, Dore gold/silver. Mine Life Revenue by commodity 3% 16% 12% 17% 52% 3 Copper Gold Silver Zinc Lead

4 Site Layout Proximity to township 3 1. Portal. 2. Concentrator Filter Plant & Train Loading Station Administration Building Old 3 Level Open cut Waste Rock Dump. 7. Rosebery 1 Hospital.

5 Geology Volcanogenic Massive Sulphide (VMS) deposit Trilobite Characteristics of VMS Deposits Size <1Mt to 50Mt to giant deposits (500Mt) e.g. Kidd Creek, Brunswick 12, Neves Corvo Host Polymetallic, Rosebery -Zn, Pb, Cu, Au, Ag Stacked Deposits, Repetition through rock sequence Occur as clusters within belts (3 to 6 km separation) Mt Read Volcanics of Tasmania, Iberian Pyrite Belt, Green Tuff Belt of Japan Present day analogue of VMS deposits are Black Smokers 5

6 Geology Volcanogenic Massive Sulphide (VMS) deposit Size - >50Mt of massive to disseminated sulphide. Mineralogy - Sphalerite, Galena, Pyrite, Chalcopyrite, Electrum (Au containing Ag). Orientation Orebodies strike NNE and dip at 43 to east. Host Package Sequence of felsic volcaniclastics. Structure Strong cleavage between two large reverse faults, Mt Black and Rosebery faults. Rosebery Y lens Orebody

7 Mine Overview Surface Underground Interaction 6 5 > One of the longest and deepest mines in operation currently in Australia (1,500 metres). > Mining areas (K, N&P, W, Y&X). > Mining Ore: Zinc (Zn), Lead (Pb), Copper (Cu), Gold (Au) & Silver (Ag).

8 Mine Overview - Current Production Areas

9 9 Metallurgy flow sheet

10 Crushing and Grinding > The Rosebery crushing circuit consists of a Primary Jaw Crusher and a Secondary Cone Crusher. > During Crushing the ore size is reduced from around 650mm to P80 of 20mm. > The Grinding Circuit consists of 2 x Primary Ball Mills and 3 x Secondary Ball Mills. 10 Secondary crusher Primary ball mill

11 Gravity Gold > Gravity gold is recovered from the grinding circuits using 2x Knelson Concentrators. > Gold Concentrates are leached in an Intensive Leach Reactor (ILR). > Then recovered from the pregnant leach solution by electrowinning and thereafter the gold sludge is smelted. 11 Gold pour Gold Doré bar

12 Flotation > The recovery sequence for sulphide minerals in the Flotation Circuit is Chalcopyrite (Cu) Galena (Pb) Sphalerite (Zn). > Payable gold and silver is recovered with the copper and lead concentrates. Copper float cells Lead float bubbles 12

13 Filtration > Concentrates are pumped to the Filter plant where they are filtered using Larox Filters. > The filters produce a dry concentrate that is then transported via rail to Burnie. Lead Larox filter Zinc concentrate 13

14 Concentrate Shipment > From Burnie, concentrates are shipped to final destination by sea. Zinc concentrate being offloaded at Nrystar in Risdon

15 Tailings Dams > Tailings is disposed of in the Bobadil Tailings Storage Facility (TSF) that is situated approximately 4km from the processing plant. > The tailings slurry is pumped into an open flume that transports the material to the Tailings Storage Facility.

16 Marketing Products: Production: Zinc: Lead: Zinc concentrate Lead concentrate Copper concentrate Gold Doré 2015 guidance (metal in concentrate) kt contained zinc kt contained copper Product sales: Life of Mine/Life of Smelter contract with Nyrstar for 100% of produced concentrate. Concentrate is transported by rail to Burnie Port. Rosebery Zn and Pb is sold on FOB basis at the Burnie Port. Zinc is transported to Hobart, Lead to Port Pirie, Copper on the open market and Gold Doré to Perth Mint. MMG have exported some quantities of zinc concentrate in the past when Nyrstar offtake fell below production. 16

17 17 Marketing Zinc Concentrate > Relatively high Zn grade (+54%), with relatively low Fe and acceptable impurity content. > Precious metals content close to payability thresholds. > Attractive Zn concentrate in China / Asian markets. Lead Concentrate > Relatively high Pb and Ag grade, along with high Zn grades and low impurity levels. > Attractive contract with payments for contained Zn, Pb, Au & Ag. Copper concentrate > A complex concentrate with high precious metals and high impurities - limits buyers. > Currently selling under a Frame contract to a trader for blending with cleaner materials. This enables the value of high precious metals and copper to be realised. Dore concentrate > Transported to Perth Mint for refining, containing approximately 60% gold and 30% silver.

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