The Jameson cell is a relative newcomer to separation science and technology. Its mode of operation and mechanisms differ drastically from the other flotation machines. It has a number of unique parameters affecting flotation performance. An experimental investigation of Jameson cell operating variables and some design features was carried out within the quartz-dodecylamine flotation system. These parameters included jet length, bias, % solids, downcomer plunge length, and tank diameter studied for up to three different particle size groups (i.e., -250 + 106, -106 + 53 and - 53 mu m). The recovery of the medium and coarse size particles dropped by 10-15% as the free jet length increased, while that of fines was nearly independent of it. The bias factor negatively affected the recovery of all three size groups almost by same proportion. The effect of the downcomer plunging length on recovery was generally negative, but it was significant only for the coarsest size groups when the plunging length was beyond 50 cm. These negative effects on flotation recovery were mostly attributed to turbulence and its particle size dependent characteristics. (c) 2007 Elsevier Ltd. All rights reserved.