L.R. Camp M.S. Summers D.M. Rapp R.B. Read 1989 <p><span>A kinetic study has been conducted to determine the influence of reagent type on flotation rates of ultrafine coal. Two ultrafine coal samples, the Illinois No. 5 (Springfield) and Pittsburgh No. 8, have been evaluated with various reagent types in order to derive the rate constants for coal (k</span>_c<span>), ash (k</span>_a<span>), and pyrite (k</span>_c<span>). The reagents used in the study include anionic surfactants, anionic surfactant—alcohol mixtures, and frothing alcohols.</span></p><p><span>In general, the surfactant-alcohol mixtures tend to float ultrafine coal at a rate three to four times faster than either pure alcohols or pure anionic surfactants. Pine oil, a mixture of terpene alcohols and hydrocarbons, was an exception to this finding; it exhibited higher rate constants than the pure aliphatic alcohols or other pure anionic surfactants studied; this may be explained by the fact that the sample of pine oil used (70% alpha-terpineol) acted as a frother/collector system similar to alcohol/kerosene. The separation efficiencies of ash and pyrite from coal, as evidenced by the ratios of k_c/k_a&nbsp;or k_c/k_p, tend to indicate, however, that commercially available surfactant—alcohol mixtures are not as selective as pure alcohols such as 2-ethyl-1-hexanol or methylisobutylcarbinol.</span></p><p><span>Some distinct differences in various rate constants, or their ratios, were noted between the two coals studied, and are possibly attributable to surface chemistry effects.</span></p> application/pdf 10.1016/0032-5910(89)80061-0 en Elsevier The influence of reagent type on the kinetics of ultrafine coal flotation article