Imperial Mining Group Ltd, a Canadian mineral exploration and development company, reports that MPlan-Dorfner ANZAPLAN has been engaged to perform the Phase III metallurgical work program on the scandium mineralization at its Crater Lake Project.
As part of this Phase III metallurgical work program, the development of an efficient hydrometallurgical process will be focused to recover a high-purity scandium oxide product from mineral concentrates rich in scandium.
Given the positive results from the Phase II metallurgical test work, which showed improved scandium mineral recoveries, the next step is to develop an appropriate hydrometallurgical process flowsheet for these mineral concentrates.
Peter Cashin, President and CEO, Imperial Mining Group Ltd
Cashin continued, “To date, we have observed that the Crater Lake scandium mineralization can be concentrated by relatively simple, low-cost recovery techniques such as magnetic separation. An efficient hydrometallurgical process will allow us to produce a high-purity scandium oxide product to provide a low-cost, local source of scandium for Quebec’s aluminum industry.”
Imperial Mining Group will conduct the Phase III metallurgical work program on a pair of mineralogically distinct bulk samples that are analogous to those employed for the Phase II development program from which mineral concentrates will be initially extracted.
The Phase III metallurgical work program will subsequently confirm a hydrometallurgical process flowsheet at the bench-scale. The aim is to economically extract scandium as 99.5% pure scandium oxide and also recover a mixed rare earth oxide co-product.
In this process, the concentrates will be dissolved in an acidic solution to create a pregnant leach solution, or PLS, from which the existing rare earths and scandium will be subsequently mined.
The Phase III metallurgical work program will also investigate whether the Crater Lake mineralization is amenable to water leach/acid soak or heap leaching methods in solubilizing rare earths and scandium. The main aim behind this exercise is to reduce the cost of reagent (acid) while improving the recovery of payable metals.
The Phase III metallurgical work program will be initiated after delivering the MET01 and MET02 samples to Germany-based Dorfner ANZAPLAN GmbH laboratories in early August 2020. This work is estimated to be completed in four months from the date of sample delivery, which would bring the completion date of the program to the fourth quarter of 2020.
In the Phase II program, simple low-cost magnetic separation methods were used to produce a scandium mineral concentrate from the Crater Lake mineralization. A mixture of wet high-intensity magnetic separation (WHIMS) and low-intensity magnetic separation (LIMS) created a mineral concentrate that yielded an incredible 88% scandium and recovered 69% of the rare earths for a single sample.
A mixture of WHIMS and LIMS on the second sample with varying scandium mineralogy also produced encouraging recoveries of 56% total rare earth elements and 78% scandium.
Further testwork using heavy liquid separation (HLS) and sensor-based ore sorting techniques demonstrated that dense media separation (DMS) and X-Ray Transmission (XRT) sensor-based sorting provide more economical options to cost-effectively produce a mineral concentrate without the necessity for chemical reagents, grinding, or excess consumption of water.
The DMS separation method yielded recoveries of 89.2% total rare earth elements and 90.6% scandium in the mineral concentrate.
We believe these next metallurgical development steps will allow us to design an efficient extraction process for this unique scandium deposit environment. Given it’s potentially critical contribution as an important supply source of scandium to Quebec’s aluminum industry, it is inherent on my team to develop an elegant and cost-effective flowsheet that maximizes returns from the envisaged operation.
Dr Yemi Oyediran, Manager of Metallurgical Development. Imperial Mining Group Ltd
About the Scandium Market
Scandium serves as a grain-refiner as well as hardener of aluminum alloys. Alloys of aluminum and scandium have excellent weldability, ductility, strength, lower density, and better corrosion resistance. The combination of such characteristics renders aluminum-scandium alloys perfect for sectors where advanced lightweight structural materials are needed for their platforms.
Scandium-modified aluminum alloys are highly regarded as a crucial lightweight material because its weight is one-third that of steel and is 40% lighter than that of titanium alloys, and still has corresponding mechanical strength properties.
Scandium is not extensively used in the aluminum alloys industry because the availability of this metal is rather limited in western commercial markets from the primary supply sources in Russia and China. Moreover, the dearth of dependable long-term supply sources to offer material for more applications has limited the market growth.
As a result, scandium is relatively higher priced when compared to other competing alloy materials such as carbon and titanium composites, restricting its wider use. The present cost of the metal oxide published by USGS denotes that scandium is traded in a price range of about US$2,000–4,000/kg for a purity of 99.99%.
Recently, Rio Tinto reported that it has created a new procedure to mine the crucial metal scandium from by-products produced at its RTFT metallurgical operation based in Sorel-Tracy, Quebec. This facility generates titanium dioxide from ilmenite extracted at the Lac Tio open-pit mine located close to Havre-Saint-Pierre.
The new procedure was developed by scientists at the Rio Tinto Fer et Titane (RTFT) Research & Development Centre. Rio Tinto has been generating scandium oxide that fulfills the specifications of the market since the H2 of 2019 as part of a pilot project.
This breakthrough on scandium is a great example of how we are looking at our operations across the world with fresh eyes to see how we can extract value from by-product streams. This exciting breakthrough in processing technology leverages our existing mining operation to provide what can be a scalable, high-quality and low-cost source of scandium oxide to markets and manufacturers.
Jean-Sébastien Jacques, CEO, Rio Tinto
This announcement is also a key validation that aluminum-scandium alloys have been recognized as a significant market potential by a leading mining player; moreover, with the constant availability of sustainable sources of scandium supply, this trend will probably witness an incremental growth where a lightweight, robust, corrosion- and heat-resistant material is needed by manufacturers.