摘要 |
Red mud bauxite residue produced in the Bayer Process is treated in a plurality of centrifuges and repulp tanks to successively wash and dewater the red mud. A final centrate liquor is obtained in a first upstream centrifuge stage which is rich in alumina and caustic values for respective recovery and reuse. The concentrated red mud cake produced in the final downstream washing/centrifuge step is low in caustic and alumina concentration permitting environmentally friendly disposal. The concentrated red mud cake is reslurried and mixed with bauxite sand for disposal in a dry stacking impoundment area. |