1888 Discovery
The Borroloola region in which MRM is based was discovered to be rich in natural mineralisation in 1888.
1955–1989 Evaluation
The ‘Here’s Your Chance’ deposit mined by MRM was discovered in 1955. Intensive drilling in the 1960s identified it as a significant deposit.
In 1977 the first feasibility studies commenced and a pilot plant and temporary camp were constructed. At that time, the high capital costs of establishing the mine prohibited the project proceeding.
The project was re-evaluated in 1989 as a source of a single high grade bulk zinc/lead/silver concentrate suitable for feeding Imperial Smelting Process smelters.
The mineral leases were issued to MIM Holdings.
1992-1995 Establishment
In 1992-1993, MIM Holdings formed a joint venture with Japanese consortium, ANT Minerals (30%) comprising Nippon, Mitsui and Marubeni to develop the resource. A full feasibility study was completed and the decision made to proceed with the McArthur River project. McArthur River Mining Pty Ltd was formed to operate the mine on behalf of the joint venture partners.
In November 1993, the McArthur River Project Agreement Ratification Act was passed by the Northern Territory Government.
MRM commenced commercial operations with an underground mine and processing plant in 1995.
2001–2005 Review and planning
In 2001, a new range of studies commenced to examine the long-term viability of the mine. At that time, the most accessible underground ore had almost been fully extracted and the underground mining operations, which comprised over 100 kilometres of underground tunnels, were becoming uneconomical.
Feasibility studies were subsequently undertaken to investigate options including an open pit development, on-site zinc refinery, power station and a weir on a local river. Terms of Reference for an Environmental Impact Statement (EIS) were released in early 2003.
In July 2003, the operation’s initiator, MIM, was acquired by Xstrata plc. (Xstrata subsequently acquired ANT Minerals’ share in the operation in September 2005 to now wholly own MRM.)
After a review by Xstrata Zinc, it was decided the project proposal would proceed but only involving the open pit development. Growing world demand for zinc, particularly in Asia, and improved refining methods, coupled with reduced operating costs and improved quality of MRM's bulk concentrate product supported the decision to make a further investment in the mine.
2005–2006 Environmental assessment of open pit development
In August 2005, MRM announced its intention to convert the underground zinc-lead mine at McArthur River to an open pit operation to enable the mine to continue production. An EIS was lodged as part of a formal assessment process by the Northern Territory Government based on the Terms of Reference issued in 2003.
This was followed by the submission of an EIS Supplement (December 2005), Public Environmental Report (July 2006) and Mining Management Plan (September 2006).
The Northern Territory Government approved MRM’s open pit development in October 2006. Later that same month, the Australian Government provided its consent under the Environmental Protection and Biodiversity Conservation Act 1999.
While the environmental assessment process was conducted, MRM commenced operating a test open pit. The first stage of this pit commenced in August 2005. This contributed ore for sampling and for processing as underground operations reduced. The test pit was subsequently extended in April 2006 when underground mining ceased.
2007-2008 Open pit development
After the approval for the open pit development, site works were undertaken over a two year timetable and were completed in late 2008. Key development milestones achieved were:
- construction of the Southern Anabranch to a temporary bund wall to allow the open pit to be expanded and support an increase in production rates
- completion of new benchmark studies into local and migratory birds, fish populations and movement and macroinvertebrates.
The McArthur River channel and the Barney Creek/Surprise Creek channels were opened for waterflow in the 2009 wet season.
In March 2007, MRM announced an AUD50 million expansion of its concentrator to increase its capacity from an annual throughput of 1.8 million tonnes of ore to 2.5 million tonnes.
2009 – Suspension, recommencement and innovation
On 17 December 2008, a decision by the Full Bench of the Australian Federal Court invalidated the original approach granted for the MRM expansion due to a procedural error by the Federal Government. As a result, all mining and civil works were suspended. MRM resubmitted its application to the Federal Environment Minister shortly after this judgement and on 22 January, the Minister gave preliminary conditional approval for the expansion subject to a 10-day consultation period. Stockpiled ore was processed at the site while mining was suspended but was depleted by 23 January at which time the operation was placed into care and maintenance. On 20 February, the Minister approved MRM’s open pit development and operations and mining recommenced.
Since then, further technological advances to the concentrator have enabled MRM to for the first time, produce a new zinc concentrate. This is supplied to electrolytic smelters and has opened a new market for MRM concentrate.
2011 – Proposed development
In March 2011, Xstrata Zinc announced it was investigating an integrated development plan involving its European and Canadian smelters to increase capacity at MRM. The plan aims to secure the long-term future of the operation in the face of a decline in the traditional international markets for the bulk zinc-lead concentrate produced by the mine.
The AUD900 million (USD900 million) plan involves an increase in mine production at MRM, the installation of proprietary hydrometallurgy technology in Xstrata Zinc’s San Juan de Nieva smelter in Spain and Nordenham smelter in Germany, and potentially, further improvements in the Brunswick Lead Smelter in Canada.
This would increase smelter capacity, create a new, guaranteed market for MRM bulk concentrate and extend the life of mine by 6 years to 2033.
The proposal involves increasing MRM mine production to approximately 5 million tonnes per year resulting in an increase in bulk zinc/lead concentrate volume to 800,000 tonnes per annum. The indicative cost of this part of the integrated plan is AUD270 million (USD270 million). During 2010, MRM produced 2.2 million tonnes of ore and 384,000 dry metric tonnes of bulk concentrate.
An Environmental Impact Assessment will be undertaken during 2011. Subject to the completion of studies and internal Xstrata and government approval, works on the project would commence in 2012.
Other areas of interest
Publications Library
Press Releases Library