“…a TOS/TOC ratio of 2 (Rosenberg and Healy, 1996)) the loss of theoretical yield caused by 20 g/L TOC is about 9 g/L Al 2 O 3 , or 7%. It has been noted that about 90 million tonnes of aluminium hydroxide is produced by precipitation from Bayer process liquors annually (Li et al, 2003), which is probably the greatest rate of production of all precipitates in hydrometallurgy. It is a slow chemical reaction, requiring high seed densities (250 to 1000 g/L), long holding times (24 to 36 h) and low temperatures (the liquor is cooled from about 80°C to about 60°C during precipitation) to maximise the yield of product (Newchurch and Moretto, 1990;Pearson, 1955).…”