As part of its mission to develop technology to assure a continuing supply of minerals, the U.S. Bureau of Mines has investigated the flocculation of a Stillwater, MT, chromite ore. The ore was flocculated at different solids contents and at different stirring speeds to determine the importance and effect of hydrodynamic factors. In acidic and basic ph, the chromite ore was flocculated with high-molecular-weight polyacrylamides differing in degree of hydrolysis. Polyacrylamides were found to bind chromite ore particles through hydrogen bonding. The anionicity of the polymer and the ph affected the degree of polymer-particle interaction, which in turn affected polymer conformation at the surface. A polymer conformation with many loops and tails was used to explain high flocculation efficiency. It was found that such a conformation could compensate for poor hydrodynamic conditions.