Effects of Desliming and Hydroacoustic Cavitation Treatment on the Flotation of Ultrafine Bituminous Coal

Testing was conducted to evaluate the effects of desliming in combination with hydroacoustic cavitation (HAC) treatment on flotation when processing nominal -150 μm Illinois-basin bituminous coal, which was obtained from a refuse stream at an operating coal-cleaning plant. Cavitation was produced either by flow through an ultrasonic resonator chamber or enhanced cavitation by initial flow through a cavitation chamber followed by flow through the ultrasonic unit. Desliming was carried out using a 102 mm diameter hydrocyclone. Flotation tests were conducted using a laboratory flotation cell for different reagent amounts and flotation times. The results indicated that desliming improved flotation substantially. Moreover, in some cases, HAC treatment provided an additional benefit by liberating ultrafine inorganic material prior to desliming.