Keywords: coal waste, waste processing, cement production, mechanical strength, chemical analysis, phase analysis, setting time, particle size distribution
Investigation of benefit of using coal wastes in cement production
Waste disposal in coal preparation plants leads to serious environmental problems. These wastes usually contain about 20% carbon, and the composition of the remaining ash is similar to clay. Addition of these wastes to cement clinker raw material utilises carbon as a source of energy. In this investigation, the effect of addition of these waste materials to the raw materials used in cement manufacture is studied. Ordinary type II cement and sulphoaluminate cement may be produced from the wastes. Mechanical strength, chemical and phase analysis, setting time and particle size distribution of the cement were studied. The results of the experiments show that an addition of about 3% of the coal wastes to the raw materials used in cement manufacture produces cements with good quality. Further, energy consumption may be reduced by up to 15%.