Revised application of synthetic flocculants in red mud separation

Alumina Partners of Jamaica (Alpart) has used synthetic flocculants in Red Mud Separation since the late 1970s. These polymers were typically supplied to the vessels at low concentrations (0.05 to 0.25 vol. % as is) following popular technical guidelines. During the late 1990s, A. [part was challenged to reduce flocculant consumption. An audit of the preparation and distribution system indicated that flocculant activity loss due to excessive degradation in the distribution piping was a major problem. Based on field experimentation, activity loss was eliminated at concentrations in the region of 0.4 to 0.5 vol. %. Furthermore, concentrations on the order of 1.5 to 1.6 vol. % improved flocculant performance on the settlers (thickeners). Since late 2000, operations have been modified to reflect these findings, resulting in: 1) Flocculant usage reduced in excess of 30%, 2) Increased stability of the settlers and washers, 3) Reduced soda losses.