In gold mining operations across the Lake Victoria Goldfield and Central Tanzania, efficient solid-liquid separation in thickeners and counter-current decantation (CCD) circuits is essential for maximizing process water recovery and optimizing leach kinetics.
1. Mechanism of Polymer Flocculation
Tailings slurries containing fine clay minerals, silica, and pulverized ore particles remain in colloidal suspension due to electrostatic repulsion. High-molecular-weight polyacrylamide (PAM) flocculants destabilize these suspensions through particle bridging, forming robust flocs with accelerated settling velocities.
2. Anionic vs. Non-Ionic Selection Criteria
- Anionic Flocculants: Possess a negative charge density (typically 10% to 30% hydrolysis). Ideal for mineral slurries with elevated pH (pH 9–11) and presence of divalent cations (Ca2+, Mg2+) which act as bridging ions. Widely utilized in standard cyanidation tailings thickeners.
- Non-Ionic Flocculants: Exhibit negligible charge. Preferred in acidic leach circuits, refractory ore bio-oxidation streams, or high-salinity process waters where ionic interference disrupts polymer chain extension.
3. Dosing Optimization & Carbon Protection
Over-dosing flocculants increases operating expenditure and causes residual polymer carryover into Carbon-in-Leach (CIL) tanks. Unadsorbed polymer coats activated carbon pores, reducing gold adsorption kinetics. Maintaining precise continuous dilution systems (0.05%–0.1% working solution) ensures rapid dispersion and maximum floc stability.
Nebrix Limited stocks industrial-grade polyacrylamides, Magnafoc equivalents, and customized mining reagents with rapid delivery to mining sites across Tanzania. Contact our mining division for on-site jar testing and trial support.