Properties of Artificial Aggregate for Orchid Culture Fabricated from Solid Wastes

摘要

The artificial aggregates were fabricated from several industrial wastes such as waste white clay at 1100 ～ 1150℃/10min in a rotary kiln and its physical properties were evaluated. The water absorption, porosity and emission rate of aggregates were controlled by changing processing methods or compositions which change the microstructure of specimens. The natural aggregates showed many macro pores( 120～180 μm), high porosity, high water absorption and low unit weight compared to artificial aggregates, while a porosity of artificial aggregates whose apparent shape is more regular was higher than that of a natural aggregates. Increasing waste white clay content in aggregates enhanced bloating during sintering, so increased the absorptivity of specimens. The void contents influenced a initial water emission and the natural aggregates showed a higher void content compared to artificial one due to their irregular shape. The artificial aggregates having shell structure showed a excellent water release control ability. Especially, for after 6 days, its water emission amount was lower than that of natural aggregates. However, artificial aggregates whose shell is removed through crushing process showed deteriorated water release ability.