Production and Characterization of Porous Anorthite Ceramics Using Sugar Process Solid Waste, Chamotte and Coal Powder Additives

Press filter cake is a solid waste produced during sugar production process and includes carbonates and organic components. In this study, coal powder in different percentages (from 10 wt.% to 50 wt.%) was mixed with 35 wt.% press filter cake and 65 wt.% chamotte composition to produce porous anorthite ceramic products with different apparent porosity percentages. The anorthite phase was observed as the dominant crystalline phase in all fired samples. The firing shrinkage values sharply increased after adding higher than 40 wt.% coal powder to composition. In addition, apparent porosity values were changed from 49% to 70%. Compressive strength values reduced from 18 MPa to 1.73 MPa while percentages of ground coal were increasing. Microstructural analysis also showed that the porosity values of the sintered samples showed important changes depending on the amount of coal additive. The thermal conductivity values showed a reduction from 0.113 W/mK to 0.064 W/mK while increasing the percentage of ground coal. Micro-computed tomography (Micro CT) analysis was performed for 40wt. % coal powder added composition and the total porosity value was found as 60.2%.