Effects of Iron Oxide on Settling Pattern and Sediment Volume of High-Swelling Smectite

Abstract

The settling pattern and the sediment volume of clay are physical indexes which reflect the degree of flocculation of clay particles and the microstructute of sediment respectively. Effects of iron oxide on settling pattern and sediment volume of high-swelling smectite were examined in this paper. As a result, the settling patterns were shifted to more strong flocculating pattern when the iron oxide contents were increased. Then it was found out that the iron oxide was a factor which enhance the flocculating character of smectite. In addition, the sediment volumes were increased in all cases of iron oxide contents when the salt concentrations were decreased. In this case, the smectite with added iron oxide preserved its high-swelling character. On the other hand, the sediment volumes were decreased a little under the low salt concentration when the iron oxide contents were increased. Then it was also assumed that the iron oxide reduced slightly the swelling character of smectite.