Abstract: A cement clinker producing system, capable of providing a gas containing a carbon dioxide gas at a high concentration by increasing a carbon dioxide gas concentration for a part of an exhaust gas, includes a cyclone preheater to preheat a cement clinker raw material, a rotary kiln to burn the preheated cement clinker raw material so as to provide cement clinker, a calcination furnace to promote decarbonation of the cement clinker raw material, a clinker cooler to cool the cement clinker, a kiln exhaust-gas discharge passages to discharge an exhaust gas generated in the rotary kiln, a combustion-supporting gas supply device to supply a combustion-supporting gas having a higher oxygen concentration than air, a combustion-supporting gas supply passage to guide the combustion-supporting gas to the calcination furnace, and a calcination furnace exhaust-gas discharge passage to discharge a carbon dioxide gas-containing exhaust gas generated in the calcination furnace.

Abstract: Chlorine-containing waste is processed inside a heating device, an alkali metal compound and a calcium compound are given into the heating device while the temperature of a solid phase inside the heating device is maintained at 400 to 1500° C., chlorine that is contained in the chlorine-containing waste and that has not been bound by the alkali metal compound is bound in the solid phase by the calcium compound, and chlorine is converted into alkali metal chloride from calcium chloride generated in the course of the processing of the chlorine-containing waste.

Abstract: Chlorine-containing waste is processed inside a heating device, an alkali metal compound and a calcium compound are given into the heating device while the temperature of a solid phase inside the heating device is maintained at 400 to 1500° C., chlorine that is contained in the chlorine-containing waste and that has not been bound by the alkali metal compound is bound in the solid phase by the calcium compound, and chlorine is converted into alkali metal chloride from calcium chloride generated in the course of the processing of the chlorine-containing waste.