In last month’s Technical Forum we promised to return to the topic of cement kiln emissions, which were said to be both simple and complex, benign and noxious. The challenge is to see the broad simplicity, which then allows the increasing complexity to be understood. By Dr Michael Clark, UK.
At the macro level cement kiln emissions are indeed simple. The raw materials used for manufacturing clinker are some form of calcium carbonate combined with other raw materials that provide the required amounts of silica, alumina and iron oxide for combining with the lime derived from the calcium carbonate to form the calcium silicate, calcium aluminate and calcium aluminoferrite clinker minerals.