Sintering behaviour of ceramic bodies from contaminated marine sediments

Abstract

The effect of the heating temperature on the properties of sintered ceramic bodies from three different contaminated marine sediments was investigated. The sintering behaviour was evaluated by means of the variation of shrinkage degree, bulk density, water absorption, open and closed porosity, while the phases transformation were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results have shown that the sintering process follows a viscous liquid phase mechanism due to the formation of a glassy phase. The optimum sintering temperature is 1125ºC for Astilleros and Cuchia sediments and 1150ºC for Raos sample. Above this temperature, a significant overfiring with an increase of closed porosity was observed. Water absorption values and mechanical properties as bending and compressive strengths of sintered bodies show that the investigated marine sediments are suitable to be used as secondary raw materials in ceramic tiles and bricks production.

Characterization of Sintered Ceramic Tiles Produced from Steel Slag

“…Tile 1 sintered to 1200˚C with the highest porosity of 31.32% also recorded the lowest bulk density of 1.82 g/cm 3 . Tile 3 sintered to 1200˚C with the lowest porosity of 11.29% recorded the highest bulk density of 2.01 g/cm 3 . Similar observations were observed for other samples though the bulk densities seem to remain constant as porosity increased.…”

“…Figure 3 shows that water absorption of samples sintered to 1200˚C decreased with increasing steel slag addition down to 40 wt% before slightly increasing with further additions. Romero et al, 2008, suggested that closed porosity dominates at high [5], which stipulated 10% to 18% and 6% to 10% for wall tiles and floor tiles respectively. Water absorption requirements for floor tiles are much lower; therefore samples generated from this work could be suitable for floor tiles purposes.…”

“…Furthermore, the practice of incorporating industrial waste in tile production is gaining ground in many ceramic industries all over the world. Consequently, several studies have been carried out on the production of ceramic products using both organic and inorganic waste like sewage sludge, natural stone waste, fly ashes, and metallurgical waste [3]. The need to characterize ceramic bodies from such combinations is not only justified, but imperative.…”

Utilisation of different types of coal fly ash in the production of ceramic tiles

“…Samples sintered at 1190 o C were nearly impermeable. The occurrence of open porosity in the sintered samples could be favoured by different causes, such as entrapped air in the ceramic slurry, formation of voids during the different drying steps, gases released in the thermal decomposition of carbonates and sulphates or even liberation of gases dissolved in quartz particles [22]. As the sintering temperature increases, the capillary pressure due to the surface tension of the liquid phase tends to approach the particles, which in turn changes the porosity from open to closed porosity, which is formed by larger, isolated, spherical pores.…”

Manufacture of Ceramic Bodies by Using a Mud Waste from the TiO₂ Pigment Industry

“…In this sense, the recovery of wastes currently generated in most industrial processes is the subject of a thorough investigation [1]. Wastes valorisation in building materials as secondary raw materials could allay the health and environment problems associated with both the depletion of natural resources and the disposal of industrial wastes [2], although the economic benefits accruing from waste recycling must not be ignored [3].…”