Evidence of coal conversion in the Majuba underground coal gasification pilot plant, South Africa

Underground coal gasification (UCG) is a conversion method that permits resources to be exploited in situ using high-temperature reactions. An understanding of the chemical, mineralogical, and petrographic properties coal, resultant unburned carbon, degasified ash (minerals) UCG zone, fundamental determining rates, gas composition, environmental groundwater risk assessments. This study aims provide mineralogical characterization residues obtained from Eskom Majuba pilot plant site South Africa. Samples were selected verification borehole (VH3) drilled at following trial. The Permian-age Karoo Basin Gus Seam medium rank C bituminous, inertinite-rich, with variable content. All samples extracted show evidence heating conversion. volatile matter content very low, mean random vitrinite reflectance values are above 5 (%RoVmr). It possible use data estimate probable temperatures achieved georeactor. this exposed maximum around 1300°C. There slight temperature gradient through seam, indicative fairly even heat distribution release gases. Cracks within coals filled molten glassy material. Most iron sulfide mineralization was transformed pyrrhotite. gasified lower levels sulfur as compared unheated seam.