Process and plant for cement clinker production

A process for cement production including a raw meal preheating step performed in a preheating zone, a calcination step in which the raw meal is brought to a temperature of approximately 800-850° C. leading to substantial decomposition of the mineral constituents of the raw meal into their oxides, and a sintering step in which the load is brought to a temperature of 1300 to 1450° C. to form Ca2SiO4 (or (CaO)2.SiO2), to further decompose calcium carbonate and partially melt the load to form Ca3.SiO5 (or (CaO)3.SiO2) in a rotary kiln, followed by cooling of the resulting clinker in a clinker cooling zone, and optionally by a clinker milling step in a clinker milling zone, wherein oil sludge is supplied in an injection zone comprised within the calcination zone, operated at a material temperature of approx. 800-850° C., said injection zone comprising the bottom discharge of the lowest cyclone stages and/or of the precalciner, if appropriate, the feed-in slope of the rotary kiln and the gas phase over the mineral bed at the material inlet end of the rotary kiln, as far as that kiln end is part of the calcination zone.

A plant for cement clinker production comprising a raw material preheating zone, a calcination zone (110), a sintering zone located in a rotary kiln (10), a clinker cooling zone (20) located downstream of the kiln (10) at the clinker discharge, optionally followed by a clinker milling zone, characterized in that a supply for oil sludge (100) is arranged for injection of oil sludge into an injection zone (120) of the calcination zone (110), operated at a material temperature of about. 800-850° C., said injection zone comprising the bottom discharge of the lowest cyclone stages and/or of the precalciner, if appropriate, the feed-in slope of the rotary kiln and the gas phase over the mineral bed at the material inlet end of the rotary kiln, as far as that kiln end is part of the calcination zone.

Method of using oil sludge as energy and raw material which comprises supplying said oil sludge directly in an injection zone part of the calcination zone of a dry cement clinker manufacturing process, operating at a material temperature of about 800-850° C., said injection zone comprising the bottom discharge of the lowest cyclone stages and/or of the precalciner, if appropriate, the feed-in slope of the rotary kiln and the gas phase over the mineral bed at the material inlet end of the rotary kiln, as far as that kiln end is part of the calcination zone.