Polymers as anti-scaling materials in the Bayer process

Scaling within the Bayer process is a widespread problem both in terms of cost of removal and the human risk associated with de-scaling operations. Here we present an overview of the possible use of polymer materials in anti-scaling applications. Preliminary results are shown from plant-based experiments where several representative polymeric materials were exposed to the liquor stream in a decanter overflow and scaling rates were measured. Preliminary results are also shown from testing these polymers in synthetic liquors for comparison of results. Optical and electron microscopy are used to characterise the scale and material surfaces at different exposure intervals. Degradation characteristics of these materials in Bayer liquor has been observed using Raman and Fourier-Transform Infrared (FT-IR) spectroscopy and these results are presented and discussed.