Beneficiation and Physiochemical Characterization of Coal Deposits in Achibo-Sombo Area, South-Western Ethiopia
Abstract This study was conducted to upgrade the quality of Achibo-Sombo coal deposits by physiochemical beneficiation methods particularly by using froth floatation technique to minimize the ash and sulfur content from coal particles. During the floatation test, proximate, ultimate, calorific value, functional groups, surface morphology and crystal structure analysis of Achibo-Sombo coal was carried out through different methods. The moisture content of a raw sample and treated sample is found in the range of 11.81 to 20.27% and 8.12 to 14.02 % respectively. The volatile matter is ranging from 22.74 to 34.85 % for raw coal and 21.92 to 30.64 % for treated coal samples. The ash content of the raw coal sample is ranging from 22.47 to 36.58 % which became in the range 7.49 to 13.62 % after treatment. The fixed carbon is also changed from 23.85–38.31% of raw sample to 44.47–55.87 % for treated coal samples. The calorific value of a raw sample is found in the ranges of 5838.46 Btu/lb. to 9531.29 Btu/lb. whereas for treated coal samples it is found in the ranges of 9438.12 Btu/lb. to 11756.63 Btu/lb. The sulfur and nitrogen contents of the raw coal sample which were ranged from 0.57 to 1.9 % − 1.22 to 1.44 % are reduced to 0.25 to 0.41% -0.52 to 0.92% respectively after treatment. Generally, the Achibo-Sombo raw coal is falling under the coal grade of lignite B to sub-bituminous B whereas the treated coal sample is grouped under sub-bituminous C to high volatile bituminous C. Accordingly, the results obtained indicate that the Achibo coal streams are upgraded relatively with better calorific value and fixed carbon and with lowest ash contents as compared to samples collected from other sites.