Mount Isa Mines

Brittania A process for removing silver from lead, operated by Brittania Refined Metals in England, using ore from the Mount Isa mine in Australia. After initial concentration by the Parkes process, and removal of the zinc by vacuum distillation, the mixture, which contains silver (70 percent), lead, and some copper is treated in a bottom blown oxygen cupel in which lead and copper are removed by the injection of oxygen through a shielded lance. 

Isasmelt A two-stage lead smelting process. In the first stage, the lead concentrate is oxidized by injecting air down a Sirosmelt lance, using helical vanes to swirl the gas. In the second, the high-lead slag is reduced with coal. The process was developed by Mount Isa Mines and the CSIRO, Australia, and due for startup at Mount Isa in 1991. 

Current address Mount Isa Mines Limited, Mount Isa, Queensland, Australia... 

Company Name Mount Isa Mines Limited Pasminco Port Pirie Smelter Hachinohe Smelting Company Sumitomo Metal Mining Co. Harima Works Hosokura Smelting Refining Co. 

The development of the mine to produce bulk concentrates and the need for assured outlets for a major part of its ouq>ut led to the decision of Mount Isa Mines Ltd. to acquire the Avonmouth and Duisburg ISP smelters. 

Mount Isa Mines Limited is part of the Glencore group of companies. 

The authors would like to gratefully acknowledge the assistance provided by colleagues at Mount Isa Mines and AECOM Australia for the thoughtful suggestions and review of content for this manuscript. ABB Australia is also acknowledged as the source of the hoist design information provided in this publication, and the Authors thank ABB for its support in the preparation and submission of this paper. 

Initial application of this process to lead (and copper) was developed by Mount Isa Mines and was termed the Isasmelt process. Other applications and later also tin, copper and lead smelting and zinc fuming were developed by Ausmelt Limited, both as licensees of the Sirosmelt technology. 

Bulk concentrates contain both zinc and lead, typically in a ratio of about 2 1. Total metal content is usually 45-60 per cent (zinc plus lead), with at least 10 per cent of each, as well as copper, and other impurities. This material is generally treated at Imperial Smelting Furnace (ISF) plants, where both zinc and lead are directly recovered. Major sources of bulk concentrates include the Mount Isa mine in Australia, the Brunswick mine in Canada, and the Red Dog mine in the USA. These mines produce bulk material in addition to larger quantities of lead and zinc concentrates. However, some smaller mines (El Brocal in Peru, for instance) have bulk concentrates as their sole product, although this is unusual. 

Sedex deposits constitute many of the world s great ore deposits, including the Sullivan mine in Canada, Mount Isa, the Broken Hill protolith, and... 

Ryall, W.R., 1979c. Mercury in and around lead-zinc-silver ore bodies at the Isa mine. Mount Isa. Unpubl. Restricted Inv. Report, 1042R, Institute of Earth Resources, CSIRO. 

The Ernest Henry Mine is situated 40km north east of Cloncurry, which is the township founded in 1867 by Ernest Hemy in North West Queensland, Australia. Mount Isa is 117km to the west and is the major mining centre in the region. Figure 1 shows a map of the area and provides a regional context. 

The Ernest Henry Deposit was discovered in 1991 and subsequently an open pit mine and processing plant has operated at a production rate of approximately llMtpa from 1998 to 2011 when the pit operations ceased. The copper concentrate containing gold is predominantly transported by road trains to Mount Isa operations for blending and treatment through the copper smelter to produce copper anode. The copper anode is subsequently transported by rail to Townsville on the east coast some 900km away where it is refined into copper cathode. 

Four candidate hoists were identified at mines located in Canada, New Mexico, Germany and Mount Isa. An assessment of the technical merits of each against the required duty and service hfe was carried out in order to identify the extent to which each hoist required modification. These were compared to the base Ccise option (new equipment). 

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