Pyrite is a common minor constituent in many mineral deposits and is associated with our coal (it is the main host of sulphur in coal, the source of acid rain) and the gold deposits of the Witwatersrand Basin.

 — In South Africa, oxidation of pyrite is increased due to high ambient temperature and spontaneous burning of coal. The concentrations of aluminum and iron are also significant, whereas the other constituents are mostly close to …

Coal is found in South Africa in 19 coalfields (Figure 1), located mainly in KwaZulu-Natal, Mpumalanga, Limpopo, and the Free State, with lesser amounts in Gauteng, the North West Province and the Eastern Cape.

 — Mineralogical analyses reveal quartz, kaolinite, montmorillonite, albite, pyrite, gypsum and sodium chlorate in the coal samples. The genetic kaolinite species identified in Imeagha (IMG) coal are detrital kaolinite and the highly crystalline neomorphic kaolinite.

 — Chatterjee (1942) reported the presence of elemental sulfur in weathered Indian coal but not in fresh samples. He suggested that, during weathering, pyrite is first oxidized to ferrous and ferric sulfates, and that then ferric sulfate oxidizes pyrite to elemental sulfur.

 — Pyrite in the coal is also one of the main components responsible for the wear and abrasion and high level of coal abrasiveness index (AI) in South African coals (Fosso-Kankeu et al., 2013). Weeber et al. (2000) postulated a possible relationship between low ash fusion temperatures (AFT) and an increase in the iron content present in the form ...

Microwave assisted extraction (MAE) followed by Inductively Coupled Plasma–Optical Emission Spectrometry (ICP-OES) were used for extraction, identifica-tion and quantification of inorganic, organic, total sulfur forms as well as selected metals related to the presence of sulfur in coal.

 — Pyrite contents of 5 %–7 % in coal has the most significant effects on spontaneous combustion within the range of this study. The conclusions are conducive to the evaluation and control for the spontaneous combustion of coal.

 — Self-heating of coal and coal-shale has been reported in South African coal mines to be capable of starting spontaneous combustion (Onifade and Genc 2018b, c, d). The reasons for coal-shale to undergo spontaneous combustion has been reported to be caused by the amount of pyrite, organic composition, reactive nature and rank of the …

 — This article presents results obtained from mineralogical and chemical characterization of coal and its combustion products from a coal burning power station in the Mpumalanga Province, South Africa. The main objective of the study is to understand the role of combustion process, chemical interaction of fly ash with ingressed CO 2 and ...