(En anglais seulement, la version française suivra sous peu)

Quest's improved hydrometallurgical process has the potential to produce a high purity mixed rare earth oxide without technically complex, risky and costly solvent extraction circuits. The key step in the new process is the selective thermal sulphation (STS).

Industrial Process Capabilities

Quest's eco-friendly proprietary industrial process is simple and is cost-efficient. In comparison to alternative technologies, Quest Selective Thermal Sulphating (STS) process is:

much simpler;
requires fewer reagents and lower reagent dosages;
separates rare earth elements from major contaminants (i.e. Fe, Al, Th, U);
minimizes process effluent and produces smaller quantities of a more inert residue;
entails lower capital and operating costs;
rare earth oxides are produced to the highest environmentally standards and in a socially responsible manner.

The STS process is designed to recover rare earths from the phosphor powder contained in florescent bulbs which, in North America, is currently creating a major environmental problem for landfills. In doing so, we gain an additional benefit in that the yield and value of the mixed REE oxide are further improved.

The process flowsheet

The mineral resources for the Strange Lake project will be mined and beneficiated to recover a flotation concentrate at the Strange Lake site. The flotation concentrate will be transported by truck to the port at Edward's Cove where it will be loaded onto ships and transported to the processing facility at the Bécancour Industrial Park for recovery of rare earths and yttrium.

Processing at Strange Lake will comprise crushing, grinding and beneficiation by flotation. The processing plant at Bécancour will comprise the direct precipitation plant (DPP) and the REE separation plant. It will include Selective Thermal Sulphation roasting and water leaching to extract the payable elements into solution followed by hydrometallurgical precipitation to recover the rare earth elements and yttrium into a mixed REE+Y concentrate. The REE+Y concentrate will be treated to recover individual rare earth and yttrium oxides.

Process Summary:

Crushing and grinding at the mine of mineralized material
Beneficiation/flotation reduces the mass of material treated and results in smaller process plant footprint at the Bécancour facility which reduces energy requirements.
Selective Thermal Sulphation roasting and leaching. The selective sulphation process greatly reduces acid consumption and drastically improves the quality of the leach solution, leading to reduced operating costs and allows for a simplified process flowsheet.
Impurity removal, producing a high purity mixed rare earth concentrate.
Separation of the mixed rare earth oxide concentrate into the individual rare earth oxides.

A limited environmental footprint

The project supply chain is designed to conform to high environmental and social standards expectations which will be subject to external audits.

Quest environmental friendly Selective Thermal Sulphating Process (STS), which, compared to alternative technologies planned in other rare earth projects, is much simpler, requires few reagents and lower reagent dosages, separates the rare earth elements from the major contaminants (including, Fe, Al, Th and U), minimizes process effluent and produces smaller quantities of a more inert residue, all of which translates into a much reduced environmental impact.

Rare earth metals are critical enablers for a wide range of green technologies. Quest will produce, in large quantities, all 14 natural elements of the lanthanide family plus Yttrium, including those considered "strategic materials". Quest STS process gives the opportunity to contribute to recycling efforts since it can extract the rare earth metals from the phosphor dust of fluorescent bulbs.

Key elements:

Wind power at the mine site.
87% of mined material remains in the North, only 13% transported to Bécancour.
Recovery and recycling of sulphuric acid in the production of mixed REE oxide.
Processing located at a designated industrial park in Bécancour.
Simple process with minimal waste streams (dry stacked, no tailings pond)
Recycled florescent lamp material mixed with the ore concentrate. First such recycling facility in North America.

Quest is dedicated to the protection and prevention of our natural, human, and social environments.