Use of HLB values for prediction of drop coalescence behavior in liquid-liquid extraction systems containing industrial extractants

A prediction of drop coalescence behavior based on HLB (Hydrophile-Lipophil e Balance) of extractants has been examined for liquid-liquid systems using industrial extractants. With a video camera, time course of coalescence wa s observed for droplets formed at the top of adjacent nozzles in water. Dro p coalescence behavior in a liquid-liquid system has been monitored for ten systems containing industrial extractants, e.g. PC88A (2-ethylhexyl-phosph onic acid mono-2-ethylhexyl ester), D2EHPA (di(2-ethylhexyl)phosphoric acid ), TBP (tri-n-butyl phosphate), MIBK (methylisobutyl ketone), LIX84I (2-hyd roxy-5-nonylacetophenone oxime), LIX860IC (5-dodecylsalicylaidoxime), TOA ( trioctylamine), Et2CO (diethylketone), BA (benzoylacetone) and TOPO (tri-n- octylphosphine oxide). Investigated parameters are the concentration and HL B of the extractants. Similar experiments were conducted with surfactants, SPAN systems for which HLB values are known. Average times needed for coale scence for the extractants are compared with those for the surfactants. Ave rage times needed for coalescence decrease with the increase in the extract ants concentration and HLB values of the extractants. HLB of the extractant s works as one controlling factor for drop coalescence.