Unburned bodies of mineral carbon coming from Colmena kilns placed in the metropolitan area of San José de Cúcuta, Colombia: Possibilities of reuse

Abstract

Abstract In this work residues from the combustion process of the mineral coal used to generate energy in the kilns of the ceramic industry in the metropolitan area of San José de Cúcuta were collected and characterized. The material collected was subjected to grain size reduction and characterized by gravimetric thermal analysis, differential scanning calorimetry, scanning electron microscopy, microstructural analysis by X ray diffraction and chemical composition from X-ray fluorescence. The results obtained show that the unburned bodies coming from Colmena kilns (which are currently discarded) still have a very high concentration of organic phase that can provide energy to the ceramic process through combustion, if they are subjected to firing temperatures above 650 °C. On the other hand, the characterization obtained shows that chemically these unburned bodies are rich in inorganic elements such as silicon, aluminum and calcium, which are present in the material as amorphous (91.9% w/w) and crystalline phase (8.1% w/w), with quartz and mullite as relevant crystalline phases. It was established that this waste can be used as a substitute of clay materials in the manufacture of construction ceramics.