Optimum conditions for unit processing of artificial lightweight aggregates using the Taguchi method

The purpose of this study was to investigate the unit processing parameters of a drying and preheating, calcination and sintering process for optimal bloating of artificial lightweight aggregates. Each process was divided into the room temperature ranges of up to 300 °C, 300 to 600 °C, 600 to 900 °C, and 900 to 1200 °C, with soaking at 1200 °C. The times allotted for the drying and preheating (room temperature ~ 600 °C) and calcination processes (600 ~ 1200 °C) were 10 to 40 minutes, and the time for the sintering process was 0 to 15 minutes. The experiment was designed according to the Taguchi method. The sintered samples were measured to determine the density and pore size. The processing time in the drying and preheating zone (room temperature ~ 600 °C) did not affect the bloating of the aggregates. The density of the aggregates decreased as the calcination time (900 °C ~ 1200 °C) was shortened and the soaking time (1200 °C) was lengthened. The soaking temperature and time had the greatest influence on the density of lightweight aggregates. The results predicted using the Taguchi method corresponded to the actual measurement results.