Abstract: A slag cement includes ground granulated blast furnace slag and ground limestone combined in a predetermined weight ratio. Limestone and granulated blast furnace slag (GBFS) are fed to a grinding apparatus in a ratio of about 3-5% limestone by weight. The limestone is a cheaper raw material than the GBFS, resulting in a reduction in production costs for the slag cement. Moreover, the addition of limestone to the GBFS surprisingly results in improved compressive strength.

Abstract: A method for producing clinker in a system having a rotary kiln and a pre-calciner, waste material is introduced into the inlet end of the pre-calciner to serve as secondary fuel for pre-calcining raw mix also fed into the pre-calciner. The waste material is substantially completely combustible and exothermic. In a preferred embodiment, the waste material includes tires, plastics and other combustible waste that has been shredded or chipped to a size that is sufficiently small to ensure substantially complete combustion of the particles as they fall through the pre-calciner.

Abstract: A method for the production of cement clinker comprises the introduction of non-traditional materials into the kiln, preferably at a mid-kiln locations. The non-traditional materials are materials that are difficult, expensive or environmentally challenging for disposal. In one embodiment, weathered clinker is introduced into the kiln to admix with the raw material mix to augment clinker production. In another embodiment, bird, animal or human manure is added to the kiln so that gaseous reducing agents can be released by the manure and combine with certain noxious gases generated during the clinker production, to thereby reduce the noxious gas output. In other embodiments, other non-traditional waste-derived fuels are added to the kiln during clinker production, including railroad ties coated with creosote, industrial, commercial and consumer rubber components, such as rubber hoses, unshredded plastics, and organic materials, such as bird and animal meal.