Through laboratory burnability tests and industrial runs carried out for 1 month in a dry processcement kiln it has been found that an oil well-derived drilling waste and an electric arc furnace (EAF) slag generated in a steel plant are suitable partial substitutes for both limestone and clay in the kiln feed. Drilling waste was available in two streams: the one, muddy and argillaceous; the other, rocky and calcareous. Both gave satisfactory burnability indexes (BI) and high percentages of replacement of limestone (up to 38%) and clay (up to 72%). EAF slag was introduced in the kiln feed at a lesser degree (20%), but promoted a better raw mix burttability: furthermore, being a non-carbonated source of lime, it allows a reduction of both thermal requirement and emission of COZ, gas responsible for the greenhouse effect. The manufacturing process of waste-based clinkers was environmentally compatible and the related cements were similar in performance to common hydraulic binders. (c) 2007 Published by Elsevier B.V.