CHEMICAL TREATMENT TO IMPROVE RED MUD SEPARATION AND WASHING IN THE BAYER PROCESS

摘要

The invention provides methods and compositions for improving the rheology of red mud removed from Bayer Process liquor. The method includes adding a flocculant and a cross-linked polysaccharide to the liquor. This combination separates the red mud from the liquor but also prevents the red mud from becoming too thick. By preventing excessive thickness, the method allows for the formation of extremely dense amounts of red mud even in primary settlers because the dense red mud can still flow. As a result a user can simultaneously enjoy both easy handling of red mud and also high recovery rates of valuable alumina and caustic from the red mud.