Characterization of a hybrid polyacrylamide and its flocculation properties in cyanide tailing suspensions

An inorganic-organic hybrid flocculant Al(OH)3-polyacrylamide (Al-PAM) with narrow molecular weight distribution was synthesized using inverse microemulsion polymerization. The hybrid polymer Al-PAM was characterized by Infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy and scanning electron microscopy, and it was found that it had a ‘star-like’ structure in which Al(OH)3 colloidal particles acted as cores linking PAM chains. The properties of Al-PAM were investigated in flocculating 10 wt% cyanide tailing suspensions. It was found that as the amount of Al-PAMM1 with high molecular weight and aluminum content increased, the initial settling rate of particles accelerated, achieving the maximum 6.6 m/h, 17.3 times the rate of the control without flocculants. The turbidity of the supernatant decreased to 35 ± 2 NTU accordingly, compared to 353 ± 2 NTU of that in the control, which meant that 90.0% of turbidity was removed from the cyanide tailing suspensions. The flocculation mechanism was further explored by floccule size and ζ potential measurements. The superior performance of cationic Al-PAM in flocculating negatively charged particles compared to commercial non-ionic GG indicated that electrostatic repulsion between tailing particles was a crucial factor in deciding the flocculation performance of the polymer. The study demonstrated that both charge neutralization and bridge adsorption were conductive to the particle flocculation.

The Study on the Preparation and Characterization of Crosslinked Polyvinyl Alcohol Microspheres

Linear polyvinyl alcohol ( PVA ) as the matrix, Glutaraldehyde as crosslinking agent, the crosslinked polyvinyl alcohol microspheres ( CPVA ) was prepared by inverse microemulsion polymerization. Influence factors for forms and particle size of crosslinking spheres such as the ratio of oil and water, reaction temperature and time, crosslinking agent and catalyst use level, stirring speed. When reaction conditions changed, the particle size would change accordingly.