Packed-Bed Column Flotation of Fine Coal. Part I. Laboratory Tests and Flotation Circuit Design

Abstract

An advanced packed column (or static tube) flotation system developed at Michigan Technological University offers the potential for sharp separation of fine coal particles from mineral matter and can be readily incorporated into practice for efficient coal processing at reduced costs. The essential element of the system is the packed-bed cell design in combination with a controlled dispersion reagent scheme. A clean coal concentrate of less than 3% ash (in some cases below 1%) was produced in a single stage of the packed column flotation at more than 90% heating value recovery from several of the major U.S. bituminous coals, including Lower Kittanning and Pittsburgh seams. A two-stage flotation circuit with intermediate regrind of the first stage concentrate for re-treatment in the second stage improved the coal quality, and/or recovery.