Up-gradation of the local coal of Cherat area, Khyber Pakhtunkhwa, for cement industry

Abstract

Every passing day prices of furnace oil and natural gas are increasing, so coal is getting importance especially in Pakistan in the current scenario of energy shortage. Cement industry is also a big consumer of coal. Only 10 percent of the total demand of cement industry is being fulfilled by local coal while remaining 90 percent is imported from foreign countries in Pakistan. About 2.5 million tons’ coal is being imported per year because our local coal possesses higher values of sulfur and ash, thus causing wastage of foreign exchange. Froth flotation, hydrocyclone classification and pneumatic classification methods are mostly applied for coal washing/up-gradation. These methods were adopted in present research to upgrade indigenous coal. In the raw coal ash content was observed to be 45.01% and sulfur content was 3.86%. After analyzing the test products, it was found that the results of Froth flotation process were more encouraging than the hydrocyclone and pneumatic classifications. Froth flotation test results show higher reduction in sulfur and ash, give maximum calorific value along with higher percent recovery of upgraded coal. Ash reduction in Froth flotation, hydrocyclone and pneumatic classifications is 44.78%, 35.16% and 19.73% respectively. Sulfur reduction in Froth flotation, hydrocyclone and pneumatic classifications is 44.48%, 29.41% and 14.80% respectively while the recovery of upgraded coal is 40.35% in the case of froth flotation, 30.25% by hydrocyclone classification and 23.64% by pneumatic separation.