Mineral Matter in Nigerian Coals and Tar Sand and their Implications in Binary Blend Formulation and Co-carbonisation

Abstract

In blend simulation for metallurgical applications, the knowledge of the type and amount of mineral matter in coal and other additives, as well as their derivatives as a result of combustion is important in assessing the coke quality and blast furnace efficiency. X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques were used in assessing the mineral matter contents and oxides produced up on combustion of the following Nigerian coals: Afuze (AFZ), Garin-Maiganga (GMG), Lamza (LMZ), Shankodi-Jangwa (SKJ), and Chikila (CHK) in addition to a tar sand from Ondo (OTS). Coal samples from Afuze (AFZ) and Chikila (CHK) were found to contain quartz, hematite, and anhydride as the dominant minerals. The Garin-Maiganga coal sample (GMG) was found to contain quartz, magnetite, anhydride, and magnesite. Quartz and hematite were dominant in Lamza coal (LMZ), while Shankodi-Jangwa coal (SKJ) is associated with dolomite and quartz. The bitumen was found to contain quartz, kaolinite, and rutile. The XRF analysis revealed the presence of sixteen elemental oxides: the most abundant being silicon dioxide, ferric oxide, aluminium oxide, sulphur trioxide, calcium oxide, and titanium oxide. Amongst the coal samples, CHK, AFZ and GMG coals have low acidic/basic and basic/acidic ratios, which indicate that cokes originating from them may form the least slag with the best blast furnace efficiency.