Kaolinite flocculation structure.

Effective flocculation and dewatering of mineral processing streams containing colloidal clays has become increasingly urgent. Release of water from slurries in tailings streams and dam beds for recycle water consumption, is usually slow and incomplete. To achieve fast settling and minimization of retained water, individual particles need to be bound, in the initial stages of thickening, into large, high-density aggregates, which may sediment more rapidly with lower intra-aggregate water content.

Kinetics of adsorption of high molecular weight anionic polyacrylamide onto kaolinite: the flocculation process.

The adsorption kinetics of anionic polyacrylamide flocculant onto kaolinite clay are examined as a function of flocculant dosage and pH. Special attention has been given to the flocculation effect during the adsorption process and the resulting inhibition of further adsorption. At pH 8.

Influence of aluminum doping on titania pigment structural and dispersion properties.

The influence of aluminum concentration on the structural properties and rheological behavior of aqueous suspensions of aluminum-doped titania pigment from the chloride process was investigated. The variation in rheological properties correlates with the change in the pigment surface properties, determined from electrophoresis measurements and atomic surface concentrations. Pigment suspensions exhibited a maximum yield stress and viscosity at or near the isoelectric point (iep).

Effects of chemical functional groups on the polymer adsorption behavior onto titania pigment particles.

The effects of functional groups on polymer adsorption onto titania pigment particles have been investigated as a function of pH and ionic strength using polyacrylic acid and modified polyacrylamides. The polyacrylamides include the homopolymer, an anionic copolymer with hydroxyl and carboxylate group substitution, and a nonionic copolymer with hydroxyl group substitution. Adsorption isotherms and infrared spectroscopy were used to examine the polymer-pigment interactions.

Sodium stearate adsorption onto titania pigment.

The interaction of sodium stearate with titania pigment particles from aqueous suspension has been investigated using thermal analysis and infrared spectroscopy combined with electrochemical studies. Thermogravimetric analysis (TGA) was used both to determine the adsorption isotherm and to investigate the interaction behavior. Monolayer coverage is determined to be 0.