The use of waste or alternative fuels and resources (AFRs) is beginning to emerge as a possible substitute for traditional fuel, such as coal, in the local cement industry. The practice of burning waste in cement kilns has been taking place in Europe for 35 years.

Cement producer Afrisam 
energy manager Paul Botha said at the Fossil Fuel Foundation of Africa’s Industrial Boilers, Kilns and Furnaces conference that traditional fuels would probably always be required. But a possible replacement of coal could be AFRs, owing to the fact that many wastes are chemically similar to coal. Waste 
coprocessing could also be seen as carbon dioxide neutral and waste is a growing environmental concern.

The cement process is energy intensive and uses coal, which is a nonrenewable resource that will dwindle in supply in about 40 years. Thermal energy is used in the process, which includes the drying of raw meal, calcination, or decarbonisation of the raw material, and an exothermic clinkerisation reaction. more [Engineering News]