Effect of ionic surfactants on bauxite residues suspensions viscosity

Measurement of the rheological property of bauxite residue sample received from an Australian alumina refinery, treated with a number of cationic and anionic surfactant in laboratory has been carried out using a Brookfield viscometer for the assessment of the effect of surfactants on the residue viscosity. Sodium laurate, prepared with an excess of sodium hydroxide, was found to be effective while direct addition of anionic surfactants (lauric acid and sodium laureth sulphate) and cationic (cetyl trimethyl ammonium bromide) produce only moderate effect on the red mud suspension apparent viscosity at 65 °C. The experimental data appear to confirm the crucial role of the cation sodium in the process of adsorption of anionic surfactants on the flocculated red mud particles.

Alteration of bauxite residue suspensions viscosity can be achieved with the use of suitable surfactant. The crucial role of the cation sodium in the process of surfactant adsorption onto the particle surface is recognised as shown in the figure.Figure optionsDownload as PowerPoint slide