High Purity Graphite
The demand for high purity graphite has increased worldwide, especially in the electrical industry due to the introduction of lithium-ion batteries and electric motor carbon brushes. The metallurgical industry also requires high purity graphite in the production of steel making equipment and for refractory and lubricants. The production of high purity graphite requires a great deal of energy and is an important source of greenhouse gas emissions.
Graphite is a naturally occurring elemental crystalline mineral of carbon. The quality of graphite is measured based on its fixed carbon content. Graphite purity can vary from 70.0% up to 99.0% and is categorized as low-, medium-, and high-carbon graphite depending on its fixed carbon mass fraction (o(C)).
In the present invention, an alkaline roasting-leaching method was used to prepare high-carbon graphite from flake graphite for further processing to achieve the required fixed carbon mass fraction of 99.0%. Compared with the conventional acid leaching, the alkaline roasting-leaching method showed a much higher fixed carbon mass fraction.
Zenyatta's Albany project has unique characteristics for producing high-purity graphite, positioning the company to compete with synthetic producers in the $13 billion per year global market. Unlike other graphite deposits that produce only amorphous graphite, the Albany deposit is characterized by its "vein-type" structure, which allows for the production of natural high-purity graphite. The high purity of the Albany graphite will make it suitable for use in a variety of applications, including graphite products such as heaters and crucibles for pulling single crystal silicon, graphite boats for liquid-phase epitaxial growth, and susceptors in metalorganic chemical vapour deposition (MOCVD) manufacturing.
