Slide Background
Slide Background

NEW RED MUD FLOCCULANTS FOR HIGH SILICA BAUXITES

Stigers, D.J. Chen, H.L.T. Vinhas, R. Viggiano, M. Rivera, C. Bagwe, R. Hu, D. Song, A. Taylor, M.

The production of alumina from bauxite requires efficient separation of red mud residue in gravity thickeners to generate pregnant liquor with low solid content. As the quality of bauxite reserves continues to decrease due to increasing levels of reactive silica, more efficient flocculants are needed to prevent these solid-liquid separations from becoming production bottlenecks and increasing costs for alumina producers. Of particular concern is the decreasing performance of flocculants when high levels of desilication product (DSP) are produced in the Bayer process, which have been determined to be bound directly to the surface of Bauxite residue solids. Cytec’s new CYFLOC® HX-7000 series of red mud flocculants have shown a unique ability to settle bauxite residues containing well over 5 wt% silica with excellent settling rates and impressive overflow clarities from field testing. The results will be presented to demonstrate the ability of this new polymer to handle the increasing silica content in the bauxite while maintaining or even improving the current flocculation benefits to Alumina refineries.