Red mud separation in alumina industry for cleaner environment

Solid Liquid separation process in the Bayer plant is an important operation which has decisive influence on quality and quantity of product. Thus it also has boaring on the economics of operation. Composition of bauxite and the bayer process condition greatly influence the characteristics of red mud and its separability, XRD ia an important tool to determine the minerological composition of Bauxite and red mud and modern instruments based on Gamma-ray radiation can help in study of mud settling characteristics in detail. Such studies along with use of Speciality chemicals like synthetic flocculant can load to optimising the operations of mud thickners and in economic design of new plant equipment. New equipments like deep thickners, high rate thickners, pressure decanters and hyper baric filters can further render the solid-liquid separation operations efficient and economical. Red mud disposal is an economic burden on the alumina producers and hence economic considerations only dictate the mode of disposal. With increasing stringency of environmental regulations, the disposal practices have undergone a sea change. Now the economics and environmental concerns together determine the mode of disposal.