189 results about "Calcium ferrite" patented technology

The invention relates to a method by using andradite one-step alkaline heat process to treat Bayer process red mud to produce metallurgical aluminum oxide. The method comprises the following steps of S1, mixing red mud, sodium ferrite or calcium ferrite, active lime and circulating mother liquid, so as to prepare raw material ore pulp; S2, performing alkaline heat dissolving-out reaction on the raw material ore pulp, so as to obtain dissolved-out ore pulp; S3, thinning the dissolved-out ore pulp, and separating liquid and solid of the thinned liquid, so as to obtain dissolved-out slag and dissolved-out liquid; S4, introducing carbon dioxide gas into the dissolved-out liquid, and decomposing carbon, so as to obtain crude aluminum hydroxide and carbon decomposing mother liquid; S5, treating the crude aluminum hydroxide by Bayer process, so as to obtain the metallurgical aluminum oxide; S6, causticizing the carbon decomposing mother liquid by lime milk, obtaining a sodium aluminate solution with high molecular ratio, and adjusting into the circulating mother liquid for dissolving out. The method provided by the invention has the advantages that the aluminum oxide in the red mud is recycled, the alkaline content in the red mud is reduced, the solid wastes are recycled, and the green utilization effect of resources is realized.