Burning wastes as an industrial resource - Their effect on Portland cement clinker

The use of industrial wastes as an alternative fuel in the cement industry is a reality in several countries because wastes are removed and economic incomes are obtained preserving non-renewable energy resources. In the present work, the effect of the addition of small amounts of ashes from pyrolysis of used oil from cars in the clinkering process of Portland cement is studied. The study simulates the burning process in an industrial furnace that uses up to 30% of this kind of waste fuel. The different behaviours of the clinker so obtained (clinkering, milling, phases, hydration, etc.) are discussed and these behaviours are compared with those of a clinker obtained without additions. Chemical analysis, X-ray diffraction, Blaine specific surface, calorimetry, Differential thermal analysis-thermal gravimetry (DTA-TG), pyrometric cone equivalent, porosimetry and mechanical strength were used as the main evaluation techniques. (C) 2000 Elsevier Science Ltd. All rights reserved.