Graphite One Resources is pleased to announce that it has completed the first three phases of its five phase exploratory Product Development Program to produce carbon-coated spherical graphite, achieving a minimum purity level of 99.98+% Cg in three samples totaling 3,000g.
The graphite purity from all runs exceeds the threshold requirement of 99.95% Cg for preparing spherical graphite and was assessed by assaying for both impurity and graphite content.
The test work used STAX graphite – the acronym for graphite that is Spheroidal, Thin, Aggregate and eXpanded — sourced from the Company’s Graphite Creek deposit near Nome, Alaska.
Product Development Test Work Confirms Anticipated Purity Levels for STAX graphite
Spheroidization, Coating and Coin Cell Production Remain on Track
The Graphite Creek exploratory Product Development Program is segmented into 5 phases, and is focused on generating preliminary materials performance data related to graphite concentrate purification, milling, spheroidizing, and coating as well as establishing the electrochemistry of the coated spherical graphite finished product.
Sample material is being produced with the goal of providing it for potential end-user evaluation. Spherical graphite is used mainly in lithium-ion batteries, the main demand-driver being electrical and hybrid vehicles.
"From the time we identified the unique mineralization of our STAX graphite, we’ve observed a number of potential performance advantages," said Anthony Huston, CEO of Graphite One.
In October 2015, Graphite One engaged TRU Group Inc. to undertake all tasks and activities related to a preliminary economic analysis of the Graphite Creek project. In that context, TRU initiated two product testwork programs:
An exploratory Product Development Program that will provide an initial baseline for, and insights into, the purification and processing characteristics of the STAX graphite and the potential quality of its coated spherical graphite product.
A Mineral Processing and Product Development Program to standards that satisfy the requirements for a Preliminary Economic Assessment (PEA) that will incorporate findings from the exploratory investigations.
The first three phases of the Product Development work, now completed, are:
In Phase 1, a 300g trial sample of the graphite concentrate was tested for air milling characteristics. Results indicate that much lower (2/3 less) air pressure is required to achieve size reduction in STAX graphite than what is typically observed for conventional flake graphite. This observation was consistent with performance advantages that were previously projected but unproven for STAX graphite.
In Phase 2, the 300g trial sample from Phase 1 was purified to 99.99+%Cg by non-acid methods at a U.S.-based purification facility and the results independently verified.
In Phase 3, an air milled 2,400g trial sample and a 300g unmilled trial sample were each given the same purification treatment as the sample in Phase 2 and the results were independently verified as achieving a graphite purity of 99.98+%Cg and 99.99+%Cg, respectively.
The graphite purity from all runs exceeds the threshold purity requirement of 99.95% Cg for preparing spherical graphite. The product purity was assessed by assaying for both impurity content and graphite content.
With the first three phases completed, the Company is proceeding to Phase 4 where the purified graphite will be spheroidized, classified and coated, in order to provide product samples and additional information on the milling characteristics and spheroidization yields.
Phase 5 will be dedicated to manufacturing coin cells, generating electrochemical performance data for the coin cells (coated spherical graphite) and demonstrating the potential reversible capacity of the coated spherical graphite product in relation to the theoretical maximum for graphite. This will provide a preliminary assessment of the spherical graphite quality and performance benchmark as anode material.
In parallel to this product development work, mineral processing test work is underway to validate the mineral processing flowsheet for the Graphite Creek project, including the generation of 5 kg of high-purity concentrate.
This part of the program is being executed at another U.S.-based mineral processing facility over a three-month period with completion currently scheduled for the end of May 2016. Upon completion of this stage of work, the graphite concentrate will be purified and processed into coated spherical graphite.
Product samples including coated spherical graphite finished product will be manufactured into coin cells for electrochemical performance assessment and will incorporate findings from the exploratory program.
The results from mineral processing and second stage product development will form the (validated) basis for the Graphite Creek PEA.