Remediating contaminated canal sediments and sewage sludge incinerator ashes using high-g gravity separation

The Knelson Concentrator is a high-g centrifugal separator used principally in the minerals industry to recover fine particles of free gold. A fundamental study of the Knelson Concentrator is currently being undertaken and the feasibility of applying such a technique to environmental problems such as remediation of contaminated canal sediments and ash from sewage sludge incinerators is being investigated. A pilot-scale Knelson Concentrator was used to process samples of canal sediment and sewage sludge ashes known to be contaminated with a number of heavy metals, such as copper and zinc. Coarse quartz particles were introduced in a number of tests to study the effect of artificial beds on the efficiency of concentration of very fine heavy particles. This work forms part of an ongoing research programme into the application of high-g separation techniques in the treatment of materials contaminated with fine heavy particles. The results from these tests will be presented and an evaluation of the feasibility of the technique given.