Using industrial solid wastes to produce calcium silicate

Wastes from the ceramic industry (known as chamotte waste) and marble industry lead to significant environmental pollution problems. This paper investigates the use of chamotte waste (as a source of silicon dioxide) and calcined marble waste (as a source of calcium oxide) as alternative raw materials to obtain calcium silicate for use as thermal insulating ceramic material. It was found that calcium silicate synthesised between 1000 and 1100°C was mainly composed of wollastonite. Calcium silicate specimens were uniaxially pressed and cured for one week. The technical properties of the cured specimens (apparent density, water absorption, water suction and thermal conductivity) were then determined. The microstructural analysis was performed by scanning electron microscopy. The results show that both industrial solid wastes – chamotte and marble – are good alternative renewable raw materials for producing calcium silicate.