Metal recovery from salt cake and other compositions

Abstract

A method for recovering aluminum metal from varied size clumps of salt cake. The salt cake clumps have varied concentrations of aluminum metal. The method includes steps of segregating the varied size clumps into smaller clumps and larger clumps, by size; separating, by aluminum metal concentration, the larger clumps into clumps of higher aluminum metal concentration and reject clumps of lower aluminum metal concentration; impacting the reject clumps to size-reduce the clumps to smaller reject clumps; returning the smaller reject clumps after impacting to the previous step of segregating; segregating the smaller clumps from the step of segregating into large clumps and small clumps, by size; separating, by aluminum metal concentration, the small clumps into clumps of higher aluminum metal concentration and second reject clumps of lower aluminum metal concentration; and separating the second reject clumps into clumps of higher aluminum metal concentration and third reject clumps of lower aluminum metal concentration. The steps of separating are each performed by magnetic repelling forces of eddy current separators. In the third separating step, the eddy current separator operates in conjunction with a splitter that collects high aluminum concentration pieces based on the trajectory of the pieces coming off the belt at the discharge rotor. The system and method may also be employed to recover aluminum metal from dross or other matter and to recover other types of metals.