Direct Extraction Metallurgy
Recognizing the importance of leveraging the
cost advantages provided by the physical location of our FOXTROT Resource,
Search Minerals committed early to look at the extraction metallurgy as an
opportunity to do more to position as a low-cost supplier. Under the leadership of
Dr. David Dreisinger, Search Director and Vice President of Metallurgy, and
with investment garnered from Federal and Provincial Government programs,
Search has developed a breakthrough Direct Extraction Metallurgical Process
(Patent Pending). This proprietary
process significantly reduces CAPEX and operational costs while offering a more
environmentally conscientious solution for managing waste residue.
Simpler is Better
After conducting numerous bench scale tests, Search developed an extraction process that provided a high quality rare earth oxide concentrate simply by crushing and treating the mineralized rock. This simpler process effectively eliminates the grinding and wet flotation stages of a more conventional extraction process reducing the amount of capital equipment required and the amount of electricity and chemical reagents used in operations.
An additional advantage of this process is the elimination of a wet tailings pond. The tailing from this process are in the form of a dry stackable residue which reduces the overall mine footprints and provides the opportunity to return tailings to the open pit area at the time of remediation.
How Direct Extraction Works
The mill feed is crushed to 3.45 mm and treated with relatively small amounts of sulfuric acid in a kiln at 200°C (low temperature) to render the REE water-soluble. After water leaching, the REE solution is purified by neutralizing the remaining acid. The REE are then precipitated into a concentrate using sodium carbonate. The rare earth carbonate is then re-dissolved in hydrochloric acid to reject remaining impurities. The REE are then precipitate again as a high- grade 98.99% oxide concentrate.