Comparative Study on Magnetite Medium Stability in a Vorsyl Separator and in a Heavy Medium Cyclone

Abstract

It is reported in the literature that a Vorsyl separator (VS) performs better than a heavy medium cyclone (HMC) when treating coals with high near-gravity material. The discussions are generally based on the results of laboratory or plant-scale data treating various coals. However, no effort has been made so far to identify the reasons behind the superior performance of a VS compared to a HMC. Medium stability is an important parameter, which affects the performance of any heavy medium separator. Therefore, an attempt has been made to study the magnetite medium stability behavior inside a HMC and VS at identical operating conditions. It is found that at any fixed-operating condition, the differential between the underflow and overflow slurry density is always less in a VS than in a HMC. Possible theoretical explanations supported by experimental data have been provided to substantiate this finding.