METHOD FOR PRODUCING IRON-MANUFACTURING RAW MATERIAL COMPRISING DISSOLUTION RESIDUE OF BAUXITE

摘要

An iron manufacturing raw material comprising a dissolution residue of bauxite containing 3 % by weight or less of Na2O and 10 % by weight of loss on ignition is prepared by mixing bauxite and an alkaline solution to form a slurry, charging said slurry in an extractor, extracting alumina under conditions that most of the alumina which is extractable from bauxite is extracted while dissolution of reactive silica is suppressed as much as possible, separating an extract and a dissolution residue while the reactive silica which is dissolved in the extract is no precipitated substantially as a desilication product, and washing and dehydrating said separated dissolution residue. By this method, it is possible to use the bauxite dissolution residue which finds no economical use, as the iron manufacturing raw material.