Author(s)

Hilda Vimbai Kaitano, Stanford Mudono

Department of Chemical Engineering, Faculty of Engineering, National University of Science and Technology, Bulawayo, Zimbabwe.

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.

Crystal Structure, Fixed Carbon, Graphite, Graphene, Microwave, Irradiation

Kaitano, H. and Mudono, S. (2023) Investigating on a Process Method of Beneficiating and Increasing the Graphite Purity to 99% Grade. Journal of Analytical Sciences, Methods and Instrumentation, 13, 39-52. doi: 10.4236/jasmi.2023.134004.