Green structural ceramic with addition of raw clay waste

Abstract

Raw clay waste is generated in the products conformation stage in the structural ceramic industry. Incorporation of raw clay waste is an alternative to make the structural ceramic sector more environmentally sustainable while reducing the consumption of clayey raw material. The Brazilian structural ceramic industry consumes 10.3 million tons of clay per month. This work aims to study the technical feasibility of raw clay waste addition in clayey mass used in the structural ceramic production. Samples of raw clay waste and clay were tested for chemical, physical and mineralogical characterization. Specimens containing waste contents, varying from 10% to 90% (wt.), were produced and burned in an industrial tunnel at 850°C. The technological properties evaluated were: water absorption, apparent porosity, apparent density, loss on ignition, firing shrinkage and mechanical strength. The results show that the addition of waste improves the evaluated properties significantly. With this, the reuse of raw clay waste in the clayey mass for production of ceramic roof tiles and blocks can contribute to the sustainability of ceramics sectors, reducing raw materials consumption and avoiding waste disposal in landfills. It becomes a feasible alternative to aim the ceramic industry comes to be a “green structural ceramic”.