Characteristics of thermal coal used by power plants in Waterberg Region of South Africa

Abstract

The current study evaluate the key characteristics of coal used by power stations in the Waterberg region of South Africa as a future alternative to South Africa’s well known depletion coal reserves. Eight coals samples used in the current study were supplied by one of South African Power Utility, Eskom power station as received from the nearby Waterberg coalfield in Limpopo, South Africa. Conventional characterization such as proximate and ultimate analysis as well as determination of sulphur forms in coal samples were carried out as per ASTM and ISO standards. The study revealed coal as medium sulphur type coal with pyritic and organic sulphurs accounting for the bulk of the total sulphur. Maceral analyses of coal showed that vitrinite is the dominant maceral (up to 51.8 vol.%), whereas inertinite, liptinite and reactive semifusinite occurred in proportions of 22.6 vol.%, 2.9 vol.% and 5.3 vol.% respectively. The ratio of fixed carbon to volatile matter, commonly referred to as fuel ration which indicates the combustion characteristics of the coal was determined. A correlation between forms of sulphur and total sulphur in medium sulphur Waterberg coals was also established.