Improvements on digestion in Bayer process

In order to increase the capacity of alumina production and decrease the energy consumption in Pingguo Alumina Plant, improvements on control techniques for digestion were researched and developed. They include improving the control of chemical composition of slurry to be digested and digestion operation status and energy consumption. Very good performances and technical and economical figures for digestion process with diaspore bauxite have been obtained by these improvements in Pingguo alumina refinery. It is proved by several year's practice that under the condition of keeping digestion yield more than 93%, alumina capacity is increased by 33%, Rp in digested slurry is increased from 1.11 to 1.18 and energy consumption in digestion process is cut down from 2.2 tons live steam per ton of alumina to 2.0 tons live steam per ton of alumina.