Australian Bauxite’s foray into rare earth elements seems to be hitting the mark with latest assay results from exploration drilling at the company’s bauxite project in northern Tasmania showing a significant increase in the extent and thickness of the rare earths enrichment within the bauxite project.
New mineralised zones appear to be trending to the northeast, northwest and to the south.
The significant anomalous rare earth elements recorded from the DL130 bauxite project west of Launceston is neodymium, which is the main component of super-magnets used in electric vehicle motors, wind turbines, smartphones and military electronics. Samples from hole DL162 however, are relatively enriched in the also valuable terbium and dysprosium, which are the most lucrative “heavy” rare earths in the current market.
Heavy rare earths are extremely rare and only currently mined in five mines in China with the exception of Northern Minerals’ pilot plant in northern Western Australia.
The latest drilling results significantly expand the prospectivity of the area to the north-west where there is a large tract of untested ground that has the right geology to be prospective.
With market demand for rare earths at a high, ASX-listed Australian Bauxite is hoping to add some unexpected value to its project with the rare earth elements accumulations it has discovered. The Sydney-based company says the rare earth elements discovery appears to increase in grade in an arc from west to north-east which the company says may be an ancient water channel.
The new results match the previous eye-catching grades with 230 parts per million neodymium oxide from just 8m depth. Additionally, drill hole DL162, the most north-western hole in the mineralised zone, recorded 11 parts per million terbium oxide with 0.8 and up to 62 parts per million dysprosium oxide. When background values of these elements are typically 0.8 parts per million and 4.1 parts per million respectively, these are significant results.
Both holes appear to have finished in rare earths mineralisation which suggests the mineralisation is still open with depth. Several intercepts have returned high cerium oxide levels of up to 2363 parts per million. Cerium has applications in material science, engineering, optics and the biomedical industry.
Importantly, the new assay results confirm the rare earths mineralisation at DL130 is zoned, which will influence the design of bulk sampling and metallurgical test work in coming weeks. The drill rig is being upgraded in readiness for drilling the possible source rock that lies to the northeast of the high-grade zone.
Australian Bauxite Exploration Manager, Paul Glover said: “This discovery is starting to take shape, but we are still at an early discovery stage. The latest set of results confirmed that this prospect is open in several directions."
Glover added that some early drill holes did not test the rare earths enriched horizon and will need to be redrilled carefully to evaluate the clay-rich zones that are sitting on the basement bedrock. The company says that because of this the prospect is now recognised to be untested to the south and will be drilled in that direction in due course.
Australian Bauxite is assessing the value of a geophysical program to map the subsurface channels that may be carrying high-grade rare-earth elements. There is also potential for the rare earths-rich clay horizons to outcrop on slopes around the edge of this plateau and this could be revealed by a shallow geophysical survey.
Management believes that as the rare earths occur in clays and are soluble, the mineralisation is an “ionic adsorption clay deposit”, which is the major deposit type that produce low-cost rare earth production in southern China. The company is designing a bulk sampling program to allow metallurgical tests to confirm the deposit type and to design the best way to produce a bulk rare earth concentrate from the mineralisation.
Australian Bauxite says it is one of only three publicly listed companies in the world targeting ionic adsorption clay-type rare earth elements deposits.
The rare earth element accumulations in northern Tasmania are relatively free of the radioactive element’s uranium and thorium according to the company which means that a simple bulk rare earth concentrate can be produced and sold to existing processing plant operators.
With prices for the super magnet elements neodymium and praseodymium having surged over the past year, interest in Australian Bauxite’s progress at DL130 will no doubt be keenly monitored by rare earths players as the company assesses the unusual concept of rare earths lurking in and around its bauxite deposit.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Matt Birney
