Rumble reopens the case for Earaheedy as zinc surges

Earaheedy carries a large but still inferred resource

Rumble Resources Limited (ASX:RTR) is putting its Earaheedy zinc-lead-silver project back in the spotlight as zinc trades above US$4,000 a tonne. The Western Australian project hosts a 94 million tonne inferred mineral resource grading 3.1% combined zinc and lead, plus 4.1 grams per tonne silver at a 2% zinc-plus-lead cut-off.

That equates to 2.2 million tonnes of contained zinc, 700,000 tonnes of lead and 12.6 million ounces of silver. Rumble describes Earaheedy as one of the largest zinc sulphide discoveries globally over the past decade, while 41Mt of the resource sits at a higher grade that the company says could support an early development scenario. Those figures remain an inferred resource, however, rather than an ore reserve or a construction-ready mine plan.

Metallurgy points to a simpler bulk concentrate route

Testwork on 2,300 kilograms of representative Chinook core produced 79% zinc recovery into a bulk concentrate containing 61% zinc plus lead. The work also found Chinook material amenable to semi-autogenous milling and coarse grinding, which Rumble says could reduce energy use and support a lower-capital, lower-operating-cost processing configuration.

A second flowsheet option uses HydroFloat technology to remove coarse barren gangue early in the circuit. Testing rejected more than 30% of barren material, and the company says this could reduce the plant footprint, operating costs and tailings burden. These are processing indications rather than confirmed project economics: the announcement does not provide a definitive feasibility study, development decision or updated financial metrics.

Exploration and partnership ambitions remain open

Chinook, Tonka and Navajoh remain open downdip and along strike, according to Rumble, while less than 30% of the targeted 70km mineralised Unconformity Unit has been effectively drill tested. The company also says deeper, geologically fertile formations that could host Mississippi Valley Type deposits have not yet been tested.

Rumble’s next technical step is to test whether the bulk concentrate can be separated into a high-grade zinc concentrate and a lead-silver concentrate, potentially allowing better recovery of silver value. The company also plans to assess market appetite for bulk concentrate and engage potential strategic partners seeking long-term supply.

The backdrop is supportive on paper: Rumble says zinc has risen 35% over the past 12 months and that treatment charges for zinc, lead and bulk concentrates have moved into significantly negative territory amid tight supply. It is also considering a joint venture or equity-level partnership to help fund a feasibility study and, if development proceeds, part of construction. Until that work produces firm economics, funding terms and a development pathway, Earaheedy remains a sizeable opportunity rather than a committed mine.