The company has engaged Saskatchewan Research Council (SRC) and Perth-based Stark Resources to conduct a collaborative study into the amenability of Mavis Lake ore to concentration by coarse, dry ore sorting.
A total of 150 kilograms of drill core was recently delivered to SRC’s facility in Saskatoon.
The sample encompasses the full range of ore and rock types exhibited at the project, including waste rock, unmineralised pegmatite, contact zone ore, and high-grade and low-grade ore.
Mineralogical assessment
SRC will conduct a mineralogical assessment of the rock and ore types to establish the various mineral assemblages, associations, and liberation characteristics.
This will proceed to an x-ray transmission amenability study to assess the viability of pre-concentrating Mavis Lake ore by rejecting coarse waste rock.
SRC and Stark will also work together to prepare core samples for an ultra-violet, laser-based amenability study with Stark’s technology partner Optimum Sorting.
This technique can reportedly detect spodumene directly and offer opportunities in the production of spodumene concentrate by separating it from the unmineralised host pegmatite.
The results and insights from these studies will inform the design of a feasibility-level metallurgical program in the new year.
Dual-track strategy
Critical’s ore sorting study forms part of the company’s dual-track strategy of delivering resource growth in parallel with fast-tracking the project’s development.
It will build on a scoping-level metallurgical program completed earlier this year, where combined heavy liquid separation and flotation testwork produced a spodumene concentrate of 5.98% lithium oxide at 87.3% lithia recovery.
Ore sorting has become increasingly prevalent within the hard-rock lithium industry as a pre-concentration stage to complement dense media separation and flotation.
The removal of mined waste rock and gangue minerals in the coarse, dry beneficiation stage offers a range of potential benefits including increased mineable tonnes, reduced haulage costs and associated emissions, reduced energy and water consumption, along with improved consistency of feed grades.
Processing flowsheets
Managing director Alex Cheeseman said Mavis Lake was open to a range of processing flowsheets.
“We have previously been very successful in generating a high-grade, low-impurity spodumene concentrate from this project with compelling metallurgical recoveries… we now want to further our understanding of the benefits that new and innovative processing opportunities like ore sorting can offer,” he said.
“Incorporating ore sorting into the flowsheet has the potential to improve the consistency and quality of our spodumene concentrate product, while widening the feed envelope to include multiple sources of raw material and reducing the project footprint and its environmental impact.”
