Portland cement clinker - by roasting mixt of unground blast furnace slag and finely ground remaining components

摘要

Portland cement clinker is produced by high temp. roasting of a mixt. of raw materials with the desired chemical compsn. including blast furnace slag and lime, or material forming lime when roasted, the blast furnace slag being introduced into the oven in the unground state as slag sand with a particle size of =0.2mm together with the finely ground remaining components. Reduces costs by eliminating grinding of the blast furnace slag. The slag is easily and completely reacted with the remaining components to form good quality Portland cement clinker. Pref. the raw materials are mixed by a wet process, the slag sand being added to a finely ground slurry of the remaining components. The slag sand is introduced separately into the cement oven in which it is mixed with the other finely ground components, =2 pref. 5 wt. % slag sand is used.