An investigation to establish the presence, quality and rank of coal from parts of Mui basin in Kenya

Abstract

A study was conducted in which Seventy nine samples of coal were collected from four different wells of the Mui basin between November, 2005 and July, 2006, and analyzed for calorific value, fixed carbon, moisture content, ash content,, volatile matter, sulphur and iron content. Calorific value was analyzed using the bomb calorimetric method, by igniting a weighed portion of each sample in the bomb for one hour and measuring the corrected rise in temperature. For sulphur, one gram of each sample was mixed with three grams of Eschka mixture and ashed at 825°C for 1 ½ hours in a muffle furnace. The resulting residue was dissolved in hot water, filtered and the filtrate reacted with barium nitrate to precipitate barium sulphate. The Sulphur content was then determined from the total barium sulphate content. Iron in the coal sample, was analyzed using atomic absorption spectrophotometry. Samples were first ashed at 950°C in a muffle furnace before extracting the iron using aqua regia (a 3:1 mixture of concentrated hydrochloric acid and concentrated nitric acid). The aim of the research was to use these experimental results to ascertain the presence of coal in the already sunk wells and also establish its quality as to whether it was anthracite coal, bituminous or lignite coal. Results of the coal quality were of vital use to the Ministry of Energy in Kenya in establishing as to whether this coal could be used for power generation or in steel industry among other uses. The coal exploration programme under the Ministry of Energy in Kenya has been going on with an aim of establishing Coal in different parts of the Country, so that it can be used to limit overdependence on imported petroleum and Coal. From the proximate analysis results, the coal samples were found to have an average calorific value of 21.16Mj/Kg, 52.16% fixed carbon, 45.89% volatile matter, 26.53% ash content, 2.10% sulphur, 2.04% iron and 2.04% moisture. About 33% of the samples were found to be anthracite. The rest were classified as 20.3% bituminous, 11.4% lignite, 11.4%peat, 3.8%carbonaceous shales, and 20.1% rock.