The Fabrication of Artificial Fine Aggregates Using Stone Sludge and Spent Bleaching Clay

Artificial fine aggregates (denoted AFA) were fabricated using spent bleaching clay (denoted SBC) generated from processed vegetable oil and stone sludge (denoted SS) produced from crushed aggregate manufacturing materials for use as functional construction materials. Each raw material was crushed to particle size finer than 150 μm, and fine spherical pellets of approximately 1 ~ 4 mm in diameter were prepared by a pelletizing process. The physical properties of the AFA were measured with different types of sintering equipment. A new type of vertical furnace that sinters fine aggregates in a fluidized bed at high temperatures was designed and tested. AFA sintered in a rotary kiln at 1125℃ showed a bulk density of 1.5 g/㎤ and a water absorption of 16%. AFA sintered in the vertical furnace at 1125℃ showed a bulk density of 1.9 g/㎤ and water absorption of 8.5%. The bulk density of the AFA sintered in the vertical furnace showed a bulk density 27% higher and water absorption 47% lower than those of AFA sintered in the rotary kiln.