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.

He said that waste would always be available and it could be used in the process for energy recovery.

The household waste with the highest energy content is mixed plastics, followed by paper and cartons and municipal solid waste. Glass, ferrous metals and food and garden waste have almost no energy content.

Botha warned that cement companies should not accept AFRs without sufficient information. Substances that should be avoided 
include anatomical hospital waste, asbestos-containing waste, bio-
hazardous waste, electronic scrap, entire batteries, explosives, mineral acids, radioactive waste, 
unsorted municipal garbage 
and high-concentration cyanide waste.

He said the drive to use AFRs would reduce the use of nonrenew-
able resources, reduce the volumes of greenhouse gases and waste at landfills, provide an alternative safe permanent-disposal waste option and support the National Waste Management Strategy.