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ALOCER: Use of Water Treatment Sludge in the Production of Ceramic Materials

The use of different wastes in the ceramic industry is widely known. The mineral wastes are mainly used as alternative sources of SiO2, Al2O3, and Fe2O3. Water treatment processes generate a sludge that is disposed in landfills, which can generate a long-term environmental impact. This project aims to evaluate the reuse of these industrial wastes in the production of traditional ceramic materials. It will be studied how the residues can affect the performance of ceramic elements from a technical point of view (mechanical strength, dimensional homogeneity, and durability in laboratory-scale samples), as well as their production parameters (process extrudability and efficiency). 
There is a wide variety of wastes that the ceramic industry can reuse. The application of thermal and/or mechanical treatments to these wastes (besides expenses related to transportation) is the main barrier to their inclusion in production processes. The significant heterogeneity of different types of wastes, their composition, and physical characteristics significantly affects the optimum proportion that can be recycled as raw material in the manufacturing of red ceramics. The progress of using these wastes in the production of bricks and tiles from a commercial and technical point of view is limited to how the presence of the alternative raw materials (or partial substitution of clay/fuels) affects the properties of the final product. For example, using sludge as a raw material changes the plasticity and consistency of the clay mixture during molding, and this effect has not been studied in detail. Even if the bricks and tiles of different sizes and geometries available in the market are molded mainly from extrusion processes, few studies evaluate the effects of wastes in ceramic products. The performance and effectiveness of the extrusion process depend on the rheological properties of the plastic clay mixture, as well as the configuration of the extruder. Particular size distribution, moisture, type/mineralogy, and properties of the clay blend are the most critical parameters.
Thus, this project will integrate a complete evaluation of technical, environmental, and economic aspects to potentialize the real application and use of sludge in red ceramic. At a technical level, it will be considered the availability of sludges (at least two), the effect on rheological properties of the plastic clay blend during molding, shrinking during the drying and firing process, as well as the final properties of the product (mechanical strength, porosity, absorption, density, dimensional uniformity, appearance, among others). 
This project will integrate post-graduation and graduation (research fellows) students.

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