Highlights

  • The Mulga Tank total resource grows 35% to 2.65 billion tonnes at 0.27% nickel, containing about 7.2 million tonnes of nickel, incorporating results from Phases 4 and 5 drilling.
  • The Indicated category nearly doubles to 1.12 billion tonnes at 0.28% nickel — a significant step for mine planning, as Inferred material cannot be converted directly to ore reserves.
  • Engineering work on capital and operating costs is complete and mine planning is under way; a scoping study is targeted within weeks.
  • An active seismic survey covering about 35 km² is co-funded under the WA Exploration Incentive Scheme to map the intrusion and identify massive sulphide targets at depth.

Western Mines Group has enlarged the mineral resource at its Mulga Tank nickel project in Western Australia's Eastern Goldfields, with the Indicated portion nearly doubling. Mining.com.au reported on 28 October 2026 that the total resource has grown by 35% to 2.65 billion tonnes at 0.27% nickel, containing about 7.2 million tonnes of contained nickel. The company (ASX:WMG) reported the update incorporates 32 further holes from Phases 4 and 5 drilling.

Resource Growth

The previous estimate, announced in April 2025, was 1,968 million tonnes at 0.27% nickel for 5.3 million tonnes of contained nickel, based on 58 reverse circulation and seven diamond holes. The updated figures add about 680 million tonnes and roughly 1.9 million tonnes of contained nickel. The Indicated category now stands at 1.12 billion tonnes at 0.28% nickel. Full details of the update, including cut-off grades and by-product content, should be read in the company's own announcement, which was not accessible for this article.

An ASX release on 6 October 2026 reported broad zones of disseminated nickel sulphide in all seven final Phase 5 holes, including 186 metres at 0.30% nickel from 109 metres in MTRC090 and 219 metres at 0.27% nickel from 81 metres in MTRC092. Narrower higher-grade zones included 2 metres at 1.29% nickel from 107 metres in MTRC091.

Scale Versus Grade

Mulga Tank is a very large, low-grade disseminated sulphide system within the Minigwal Greenstone Belt. The average grade has held at around 0.27% nickel while tonnage has grown, meaning the project's economics will depend heavily on bulk open-pit mining costs, metallurgical recoveries and the value of any by-products. Moving more of the resource into the Indicated category matters because Indicated material carries greater geological confidence and can be used in more detailed mine planning; Inferred material cannot be converted directly into ore reserves.

Engineering and Seismic Work

Managing director Caedmon Marriott told Mining.com.au that engineering work on capital and operating costs has been completed and that mine planning and scheduling are under way. A scoping study is targeted within weeks. Separately, an active seismic survey covering about 35 square kilometres of the Mulga Tank complex is in progress, co-funded through the Western Australian Government's Exploration Incentive Scheme, with the grant increased to A$300,000. The survey is designed to map the intrusion and identify targets for higher-grade massive nickel sulphide at its base. In early October the company said the survey would take about three weeks once access roads reopened.

Qualifications and Next Steps

Scoping studies are preliminary and carry a wide margin of uncertainty; they cannot by themselves support a decision to build a mine. Low-grade nickel projects are sensitive to nickel prices and processing costs, and the Australian nickel sector has faced difficult market conditions in recent years. Stated milestones are release of the scoping study, completion of the seismic survey and follow-up of any deeper targets identified.