Montero Mining and Exploration (CVE:MON) said Tuesday that it has identified measurable amounts of strontium in bastnaesite-bearing carbonatite dikes in the Twiga Zone at its Wigu Hill rare earths project in Tanzania.
The Wigu Hill property was first identified in the 1950s as a high grade deposit, with a large carbonatite complex measuring 6.4 by 3.2 kilometres. The asset has bastnaesite mineralization and is considered a "look-a-like" to Molycorp's (NYSE:MCP) Mountain Pass project. The rare earth elements at the deposit are hosted in the mineral bastnaesite found in carbonatite dikes, making it similar to Molycorp's Mountain Pass deposit in the USA.
Rare earth elements, a group of 15 metals, are critical in the development of emerging green technologies and high-tech applications, from electric and hybrid vehicles and wind and hydro power turbines, to LCD screens, MRI, X-ray machines, mobile devices and other computing equipment.
The strontium found at the site occurs as strontianite (SrCO3), the company said, which is associated with the rare earth and gangue minerals, and was established during initial mineralogical work that identified bastnaesite and synchisite as the main rare earth-bearing minerals.
"In addition to the rare earth concentrations in the Wigu Hill carbonatite dikes, the added presence of strontium is a positive new development," said president and CEO, Dr. Tony Harwood.
"Metallurgical testwork has indicated the strontianite can be leached into solution, suggesting a potential by-product to the extraction of the rare earths. Ferrite magnets, glass applications and pyrotechnics remain the top end-use industries in strontium consumption. This is an exciting development as we continue to create value at Wigu Hill."
Indeed, strontium was determined as being of potential economic importance once it was found that the mineral could be leached into solution during acid leach testwork done by Mintek, South Africa's national mineral research organization and the company's research provider. Additional testwork is proposed to establish a recovery procedure to extract the strontium from this leachate.
Together with Mintek, Montero has been active in mineral processing and metallurgical testwork to test the Wigu Hill carbonatite material for recovery of rare earths.
A review of the distribution of strontium in the trench and drill hole samples from Wigu Hill was done, proving the presence of "significant amounts" in the carbonatite dikes, Montero said, of between 1% to 2% SrO.
The average SrO content of the composites used for the Twiga and Tembo resource estimates is 1.4%. Around 10% of the composites appear to belong to a higher grade population with grades in the range of 2.5% to 6% SrO, with localized concentrations up to 10.80% SrO, Montero added.
Montero said in a statement Tuesday: "The presence of strontium is being investigated in more detail to establish the potential of realizing value from this element as a by-product to the production of rare earth elements at Wigu Hill.
"There is a consistent association of strontianite with the bastnaesite and although this association is not directly proportional, it has the potential to be economically valuable."
The company said it is planning a "systematic assessment" of the distribution of strontium in the mineralized carbonatite dikes at Wigu Hill, which will help in determining the potential value-add.
Montero is working to update the initial NI 43-101 compliant resource estimate for the project this quarter, and is targeting cash flow from a small mining operation at the Twiga Zone.
Last September, the company released a 3.3 million tonne inferred resource on only a fraction of the Wigu Hill complex. Only the Tembo and Twiga deposits on the eastern side were estimated to contain an inferred resource of 3.3 million tonnes at a grade of 2.6% light rare earth oxide (LREO5).
Montero is focused on upgrading the resource, and has hired Turgis Consulting to perform a scoping study on the property, due out in the first half of this year.
Earlier this month, the company said that rare earth dike mineralization from its flagship Wigu Hill property was proven to be amenable to upgrading by X-Ray sorting, with over 80 percent recovery.
The junior miner, headquartered in Toronto, said its initial X-Ray sorting tests done on bastnaesite rich samples and waste rock samples from the Twiga zone showed that ore is amendable to X-Ray sorting, with samples upgraded by 55 percent, based on lanthanum and cerium content. Moreover, more than 80 percent of the rare earth elements were recovered in the feed.