Application of coal wastes to clay bricks and investigation of their physical properties

The reuse of coal waste byproducts formed during mine development or the digging process is important for solving environmental problems and increasing waste material recycling. In this study, specimens were prepared by mixing 10, 20, 30, 40, and 50% of coal waste with brick body. Water absorption and compressive strength were investigated as functions of the amount of coal waste and the calcination temperature. Increased coal waste content generally increased the water absorption and decreased the compressive strength. When up to 30% coal waste was mixed into clay at 1300°C, the specimens satisfied the 1^st-class brick criteria of the Korean Standard (water absorption < 10%, compressive strength > 210 kgf/cm²).