Refractory Materials Manufacturing Based on Sewage Sludge

Abstract

The process of wastewater sludge disposal with the subsequent application of the reaction product was developed. The waste of galvanic production after dehydration on the filter press to the humidity of 75–80% was transferred into the chamber with a heater. Concentrated sulfuric and phosphoric acids were added as well. Dark green liquid of high viscosity was forming. Its density made up 1.67 g/cm³. Electrocorundum was thoroughly mixed with a different amount of adhesive and was laid into the forms. After drying at a particular temperature, the samples were tested. Unit weight of obtained samples increased from 0.57 to 0.9 g/cm³ with the rising of the adhesive content, while the strength was decreasing. More durable samples were obtained if the filler was dry electrocorundum. When the weight ratio of the adhesive to the electrocorundum mass increases, the concentration of chromium grows as well. The optimal composition for the manufacture of durable and water-resistant samples is the composition of 40 g of adhesive (from heavy metal hydroxides) with 100 g of electrocorundum.