STUDIES ON THE SETTLING BEHAVIOUR OF REDMUD

Abstract

India is rich in Bauxite and most of the Indian Bau-xites contain relatively higher amount of titanium oxide in highly dispersed form. During its purification by Bayer' s process, this dispersed titanium oxide creates great problem in settling operation of redmud and in the filtration of diges-ted liquor. The dispersed titanium oxide forms a stable sus-persion with digested liquor in settling tanks and takes very long time for settling. !o filter off these fine particles efficiently are also difficult. Due to these difficulties alu-minium plants in India are facing low production rate. Keeping above problem in mind, in the present work a settling apparatus has been designed which can be used for determining the settling?"° characteristics of- redmud under plant conditions, and the effect of flour addition, solid contents and temperature on the settling characteristics of • redmud, obtained from Hindustan Aluminium corporation Ltd., has been investigated. The result of this study are certainly encouranging and suggest the addition of flour as a floccu- lant by 0.01 pet. wt. of redmud f or effective settling of • redmud.