Red Metal’s metallurgical testwork has given a green light to the rare earths at its Sybella play near Mount Isa in Queensland, with bulk mining and a low-cost heap leach process to lead to a potential mining operation.
The company says granite-hosted soft ore that appears to be abundant in its ground, offers simple crushing and processing options that provide an economic edge to the project.
Management has not been shy with the superlatives used to describe the Sybella project, dubbing it both “globally unique” and “metallurgical nirvana”. It believes it is “all about the ore” because of the advantages offered by the soft, soluble rare earths that can be easily extracted using a low-acid solution.
Red Metal says it has many advantages with the soft ore, ranging from the relatively simple time-saving crushing process, to reduced processing costs from energy savings, low impurity levels after leaching and no requirement for an expensive hydrometallurgical plant for extreme heating and cracking of the ore.
The Sybella deposit sits on 12km-long by 3km-wide granite-pervasive ground that features ore susceptible to simple low-temperature processing, with management suggesting a resulting likelihood of a low-capex operation. The ore offers free-digging for the first 10m across its ground and potentially 20m in some areas, before the more expensive drill-and-blast process would be required.
Red Metal managing director Rob Rutherford said: “The key is a low acid-consuming ore mineral in a non-reactive, non-acid consuming granite rock. Those two factors together are what make tier-one deposits in the copper space and we think we have found one here in the rare earths space.”
Rutherford added that BHP’s giant Escondida copper mine and Freeport-McMoRan’s huge Morenci copper operation contained the same properties.
The company recently conducted intermittent bottle-roll tests on reverse-circulation (RC) drill chips from the weathered and fresh granite, which showed the ore to be ideal for a heap leach processing operation. The testing confirms metal recovery rates and the chemical consumption of ore in a hydrometallurgical process.
Red Metal is also conducting impurity removal trials and column leach tests to improve metal recoveries and to confirm the bottle-roll tests. Management believes completing its varied metallurgical testing on the ore allows it to better understand the potential for processing and extraction prior to engaging in expensive drilling programs.
The recent tests followed the company’s methodology and with what it now believes are “excellent” results, a step-out drilling program to expand the mineralisation outside the known boundaries has been completed. An 8km-by-3km area was tested to prove continuity of grade, with 120 holes drilled for 8171m.
Two zones of high-grade mineralisation, each about 1km wide, were unearthed and have the potential for massive tonnage. Once results from the submitted assays are returned, the company will complete infill drilling to upgrade to a mineral resource and hammer out a mining study.
Red Metal recently revealed that tests conducted by rare earths metallurgical specialists ANSTO Minerals had validated its breakthrough leach results using chip samples from Sybella. The company says ANSTO’s supplementary findings back up its phase one testwork – which was completed by Core Resources and revealed in February – that showed high recoveries and low impurities using low levels of acid consumption for both valuable magnet and heavy rare earth oxides.
ANSTO Minerals is an arm of the Australian Nuclear Science and Technology Organisation – a statutory agency that reports to the Federal Parliament. It ran similar bottle-roll leach tests to the ones carried out by Core, using the coarse non-pulverised RC chip samples.
Red Metal has other assets, including a 44 per cent stake in its “spun-out” former lead-silver project, now operated by Maronan Metals. Maronan has a pair of 30 million-tonne ore bodies on its hands from that project to keep it busy.
But on its own doorstep, Red Metal appears to have a metallurgically-unique project that may eventually propel the company into its own state of nirvana.
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By Craig Nolan
