MAXIMUM THROUGHPUT IN MULTISTAGE MIXER-SETTLER EXTRACTION COLUMN

A multistage mixer-settler extraction column, which achieved larger throughput at higher agitation rate, was developed. Each stage consisted of an upper settler chamber and a lower mixer chamber with a lifter-turbine impeller. The continuous phase was led through a downspout from the settler to the mixer of lower stage, and the dispersed phase through a riser from the settler to the mixer of upper stage. The large throughput is produced by the suction pressure with the lifter-turbine impeller, which was ascertained by the measurements of pressure in the column. The operation was stabilzed by installing a drop coalescer between the settler and the mixer, and a lattice of mesh sheet coated with PTFE gave superior performance as the coalescer.