Dense‐medium separation of heavy‐metal particles from soil using a wide‐angle hydrocyclone

Abstract

Wide‐angle hydrocyclone tests were conducted to separate fine (‐150 μm) particles based on differences in particle density. Mixtures of ferrosilicon (FeSi) and quartz or lead and soil of similar size ranges were separated in a 25.4 mm diameter hydrocyclone under various test conditions. Separations were made in dense‐medium suspensions of fine magnetite and water to improve the overall separation efficiency compared to water‐only separations. For the FeSi/quartz mixture, when the suspension relative density was raised to 1.4, FeSi recoveries exceeding 89% with quartz recoveries over 90% were obtained in a single pass through the hydrocyclone. For the lead/soil mixture, lead recoveries exceeding 97% with soil recoveries over 95% were possible at a suspension relative density of 1.3.

Key words:

• Water‐only cyclone
• soil washing
• autogenous cyclone
• waste remediation