Analysis of the technical and environmental viability of adding waste from thermoelectric and coal processing in clay ceramic paste

ABSTRACT

The investigation aims to analyze the technical viability of addition the waste from the filter-press from the mineral coal treatment process (TFP) and bottom ash from a thermoelectric (CP), in ceramic paste on the laboratory scale. Physical-chemical characterization and waste classification tests were carried out. Subsequently, ten formulations were developed through the mixture design (DoE), incorporating these residues into a standard clay ceramic paste (STD). The samples were formed by extrusion without vacuum and subjected to heat treatment in an oven and fired in a muffle at 900 °C. The evaluated technological properties were: shrinkage of drying and firing, water absorption and mechanical resistance and, finally, efflorescence tests and phytotoxicological analysis were performed. The results of solid waste classification, indicated these as not being dangerous (Class II-B - inert). The technical analysis of the samples show that compared to the clay ceramic standard formulation (STD), the other mixtures obtained results within the technical parameters, which can later be carried out in an industrial scale test. Although the mechanical tests with waste incorporation were below the standard formulation (STD), a test on an industrial scale is not discarded. In the efflorescence test, it was observed that there was no presence of soluble salts. And finally, in the phyto-toxicological test, with Allium cepa L. of a formulation with aggregation of all raw materials, it presented a result marginally similar to the standard, proving itself capable of reproduction on an industrial scale.

Keywords
Clay Ceramic; Allium cepa L; Wastes; Coal Wastes; Bottom Ash