The technical basis for making calcium sulfoaluminate cement (C$A) will use conventional cement making equipment, but with certain essential modifications to enable sulfur combustion and thereby reduce the output of carbon dioxide (CO2). The main novel process modification is the introduction of sulfur combustion partially or wholly replacing fossil fuel in the kiln, the calciner or both.
The use of sulfur here will offset the use of hydrocarbon fuel, reducing operating costs whilst essentially sequestering a portion of the sulfur in the solid clinker product. The impacts of this novel modification are to reduce the consumption of natural gas, reduce the volume of CO2 produced and sequester solid sulfur formed in the local gas processing industry. The novel process route will (i) save an estimated additional 100-200 kg/tonne of CO2 per tonne of cement (ii) lessen need for CO2-intensive Portland cement and (iii) convert several Qatar wastes from a hazardous liability to useful products. The process will convert elemental sulfur- identified as a major hazardous waste in Qatar- to a useful non- toxic and insoluble cementing product. It will also utilise iron and aluminium wastes from aluminium production as cement components.