NGC Produces 99.99%Cg spherical graphite The trials were highly successful in purifying spherical graphite to levels ranging from 99.93% Cg to 99.99% Cg. The requirements of battery manufacturers vary in particle size and purity with the latter specification usually being in the 99.9 to 99.95% Cg range. Large flake graphite was purified to levels ranging from 99.73 to 99.83%Cg with further improvements possible.
The next steps will be to further scale up the process in a Pilot Plant test that will enable Hazen to define operating parameters at a commercial level and to estimate capital and operating costs. The ultimate objective is to define a purification process that works not only with spherical graphite for battery use, but also flake graphite and micronized flake graphite for other applications requiring high purity.
The proprietary purification technology developed by Northern and its metallurgical research partners is much more environmentally friendly than the Chinese approach and operates at significantly lower temperatures than traditional thermal methods. It also involves relatively low retention times in the furnace and will likely be a continuous rather than a batch process. As a result, costs should be significantly lower.
Hazen Research is currently purifying larger quantities of spherical graphite to provide potential strategic partners in the battery industry with samples made from Bissett Creek ore that has been processed using Northern’s commercial mill flow sheet and purified in an environmentally sustainable manner. It has already been successfully tested in batteries at the National Research Council of Canada.