Heating Rate Effect during Sintering on the Technological Properties of Brazilian Red Ceramics

Unbalanced energy consumption in the production of ceramic artifacts is responsible for considerable undesirable impacts, such as increased emissions of polluting gases, excessive consumption of fuel materials, land degradation and unpredictable financial costs. By contrast, the practice of optimizing the ceramic sintering, which in associated with firing of high temperature, can result in increased productivity and reduced production costs preserving an environmentally friendly production system. Moreover, it allows further improvements in the quality of the final product. This work compares the effect of different sintering cycles, with heating rates of 2, 15 and 30°C/min, on the technological properties of a Brazilian industrial clay ceramic body. Initially the clay ceramic specimens was characterized in terms of mineralogical, chemical and physical properties. Specimens were prepared by extrusion and fired at temperatures of 800, 900 and 1000°C. The evaluated properties by standard tests were water absorption, post-firing linear shrinkage and flexural strength. It was found that owing to sintering carried out at higher heating rates, red ceramic products with superior technological properties were obtained. This is an unprecedented conclusion for common clay ceramics produced in Brazil. Based on the promising obtained results it is evidenced, in a clear and detailed way, the benefits of rapid sintering cycle application for conventional brick production.

Environmentally Clean Ceramics Manufacturing With Application of Hazardous Car Production Mud and Galvanic Process Glass Waste

It was developed new ceramics composites with hazardous car production mud (CPM) and galvanic process glass waste with high content of heavy metals. They were applied as valuable components of red ceramics sintered at 700°, 750°, 800°, 850°, 900°, and 950°C to provide flexural resistance of up to 17.6 MPa, water absorption at 950°C 6.53 -10.45%, linear shrinkage – 5.24-6.29%, density 2.7 – 3.2 g/cm³, and dilatation coefficient 5.3 -13.8%. Structure formation studies by the XRD, SEM, EDS, and LAMMA methods demonstrated the synthesis of amorphous glassy material with small inclusion of mullite Al6Si2O13. Car production mud and galvanic process glass waste play the role of the intensifiers of the ceramics’ structures formation processes. The ceramics' leaching and solubility tests by the atomic absorption spectroscopy method showed strong chemical bond of heavy metals of the hazardous raw materials in insoluble structures. According to Brazilian standards, they can be used to produce tiles, bricks, blocks, and similar materials with high environmental eficiency.

Making the ecological brick using powder residues of Ceramic Tiles

The residues generated by the ceramic factories, among the most varied types, represent a large part of the waste produced and the one that comes from the production of red ceramics such as tiles and bricks, reflects in great part of all the constituents of these residues. The use of tailings is becoming an increasingly common practice, often because it does not have a correct final destination and in some places, there is a shortage of natural materials. The present work aims to study the addition of residues of ceramic tiles dust in the characteristics and properties of ecological brick. A literature review on the topic was carried out, in addition to granulometric characterizations, absorption tests, thermal comfort and simple compression. After carrying out the tests, the possibility of using it as a component of the ecological brick and using it in the region of Teresina-PI was studied. The samples produced with tile powder residue showed excellent results, therefore, through this study it was possible to prove that the reuse of these residues is valid for use in civil construction.