CARBONACEOUS EXTENDERS FOR FLEXIBLE CEMENT

摘要

A flexible cement stable at high temperatures contains an extender that is a finely ground carbonaceous material, for example a bituminous coal and/or a finely ground coke prepared from coal and/or liquid hydrocarbons. Preferred cokes are made from bituminous coals and from petroleum, heavy oil, and oil from tar sands, oil shales or oil sands. The carbonaceous material is present in an amount up to 100 percent by weight of cement and the particle size is preferably from 1 to 1000 microns. The carbonaceous material is also effective as an extender, and the slurries and set cements have low specific gravity. Optional additives include silica and Wollastonite.