In pyrotechnics, it is used as a fuel to make special mixtures, for example for the production of smoke, in flash compositions, and in percussion primers. Specification for pyrotechnic calcium silicide is MIL-C-324C. In some mixtures it can be substituted with ferrosilicon. Silicon-based fuels are used in some time-delay mixes, for example to control explosive bolts, hand grenades, and infrared decoys. Smoke compositions often contain hexachloroethane; During combustion they produce silicon tetrachloride, which, like titanium tetrachloride used in smoke screens, reacts with moisture in the air and produces dense white fog. Gum arabic is used in some blends to inhibit calcium silicide breakdown.
It is insoluble in water, but can decompose when subjected to moisture, the evolution of hydrogen, and the production of calcium hydroxide. It decomposes in hot water.
It is flammable and can ignite spontaneously in air. Industrial calcium silicide usually contains iron and aluminum as the primary pollutants, and low amounts of carbon and sulfur.
Calcium silicide is used for the manufacture of special metal alloys, for example for the removal of phosphorus and as a deoxidizer.
The self-heating cans of military food rations developed during World War II used a termite-like 1: 1 mixture of iron (II, III) oxide, calcium and silicide. Such a mixture, when ignited, generates a moderate amount of heat and does not generate gaseous products.
Calcium silicide, CaSi, prepared in an electric furnace from lime, silica and carbonaceous reducing agents, is useful as a deoxidizing agent for steel.