抄録
Grain-size distributions of both the underflow and overflow from the hydrocyclone circuit with hydrocyclones C1 and C3 are studied both in the full-scale plant and bench-scale plant. The separation performance of a hydrocyclone is expressed by a separation curve representing the probability of a particular particle ending up in either the underflow or the overflow. A particular configuration of a hydrocyclone circuit with C1 and C3 can benefit both separation performance and production of clean, good quality sand to minimize misplacement of fine particles between sand and sludge (fine fraction). After the first cycloning step, the separated flow with fine particles (C1 overflow) may still contain sand particles which increase an amount of residue. Cyclone C3 is included in the cycloning process to remove any sand fraction still present in the sludge. This can considerably reduce further the landfill cost.
A mathematical model was developed to simulate the steady-state grain-size distribution of the C1 underflow (UFC1), which represents the clean sand, in the hydrocyclone circuit with C1 and C3. It was shown that the grain-size distribution of UFC1 is better described by the presented model, which helped determine an amount of clean sand and the cost of soil washing for contaminated soil. The concept and numerical formulas of the presented model are introduced and discussed.
