TITLE:
Investigating on a Process Method of Beneficiating and Increasing the Graphite Purity to 99% Grade
AUTHORS:
Hilda Vimbai Kaitano, Stanford Mudono
KEYWORDS:
Crystal Structure, Fixed Carbon, Graphite, Graphene, Microwave, Irradiation
JOURNAL NAME:
Journal of Analytical Sciences, Methods and Instrumentation,
Vol.13 No.4,
December
29,
2023
ABSTRACT: The
main aim of this project was to come up with an efficient method for the purification
of graphite to at least 99%. There has been an increasing demand for high-grade
graphite products with up to 99.99% carbon that has resulted in the development
of various approaches to remove impurities even to parts per million range.
Removal of impurities from 94% graphite is important to achieve a high-purity
graphite product. Microwave irradiation was used to prepare high-purity
graphite from 94% graphite concentrate. The results showed that microwave
irradiation could enhance the fixed carbon of flake graphite to a higher level.
Under the optimum conditions selected of 4 minutes’ reaction time and 100%
microwave output (800 W), a graphite product with a fixed carbon content of 98.845% was
obtained from flake graphite concentrate. According to XRD, FTIR and Handheld
XRF analysis, impurities mainly composed of Fe, Co, Sr and Zr were present
before treatment. After treatment under optimum conditions Fe, which was the
major impurity in the sample was reduced from 3.566% to 1.031%. The ash content
of graphite under optimum conditions was 1.55%. The crystal structure of flake
graphite showed no change. It can be concluded from this study that graphite
purification using microwave irradiation increases the carbon content of
graphite.