INCREASING THE EFFECTIVENESS AND SELECTIVITY OF CRYSTAL GROWTH MODIFIERS

Crystal growth modifiers (CGMs) are used extensively in Bayer plants to assist with particle size control within the precipitation circuit. In developing a range of more effective, second-generation CGMs, the primary aim has been to further enhance the coarsening potential of these products. Concurrent investigation of the mechanisms by which they function has also been part of the development and this has provided added insight into application optimization and provided direction for continued development. The result is a range of new Nalco products that are significantly more effective coarsening agents that cater more effectively to the particular requirements of individual plants.

Laboratory data presented here examines the coarsening effectiveness of these new chemistries. Additionally, data is presented assessing the optimum point of addition and the adsorption properties of these new products and this provides some insight into their mechanistic behaviour.