Abstract

Three kinds of acid were used to leach bottom sediment soil of water reservoir to diminish aluminum from the soil for preparation of lightweight aggregates. Three concentrations were used in these investigations, including 1, 2 and 5 N. Operating temperatures were set at 25, 50, 70 and 90 celsius. Measuring took place in 1/2, 1, 2, 4 and 8 h. Comparison of before and after leaching, the spectra showed that the mineral composition of chlorite disappeared after acid leaching with a sound effect. Among the three acids, sulfuric acid is the best leaching solution under same operating conditions. The best combination for maximum extraction in this study is 5 N sulfuric acid with temperature set at 90 celsius and 8 h of reaction. We could reach a removal of 3019 ppm aluminum from reservoir bottom sediment soil. This non-aluminum contained soil is great, both in hydration and swelling as a good quality of lightweight aggregate matrix.

Key words: Leach, bottom sediment soil, aluminum, lightweight aggregates, chlorite.