Reactions of calcium compounds and coke for preparation of calcium carbide

To understand a novel process for preparation of calcium carbide (CaC₂) from pulverized feed stocks, the reactions between a coke and various calcium compounds including calcium carbonate (CaCO₃), calcium hydroxide (Ca(OH)₂), residue from the reaction of CaC₂ with water, CaSO₄ (the main compound in FGD residue) and calcium oxide (CaO) were examined in a TG-MS system up to 1850℃. The results show that all the calcium compounds, except CaSO₄, can be used directly for CaC₂ preparation, which starts at about 1450℃ and peaks at about 1740℃. The H₂O and CO₂ generated from the decomposition of the calcium compounds have little effect on CaC₂ formation. At about 920℃ CaSO₄ reacts with coke to form CaS, which does not react further with the coke in the temperature rang studied.