Application of oil-products-containing water treatment sludge in wall ceramics production

The article presents the research findings concerning the usage of carbon-containing water treatment sludge of test solutions, containing emulsified oil products, in raw charge for wall ceramics production. For removing oil products kieselghur sludge was used, generated at the refined vegetable oil production at winterization stage (removing waxes and waxlike substances), thermally modified at temperature 450°C. Water treatment sludge is characterized with organo-mineral composition. It was determined that baking ceramic samples with water treatment sludge at temperature 950°C causes the oxidation of oil products with the formation of gaseous products CO, H₂O and CO₂, which makes ceramic materials' structure porous, which in its turn reduces their density and improves their heating-performance characteristics. The presence of organic substances in the charge for ceramic materials creates favorable thermodynamic conditions for iron oxides reducing reactions, which contribute to the formation of low-temperature silicate melt and intensify the samples' baking process. The wall ceramics products, obtained with the use of water treatment sludge, can be used as construction material and heat-insulating material in enclosing structures and at internal partitions installation. (paper)