Recovery of manganese from steel plant slag by carbamate leaching.
Reno, NV: U.S. Department of the Interior, Bureau of Mines, RI 9400, 1992 Jan; :1-10
The U.S. Bureau of Mines investigated the feasibility of using ammonium carbamate (NH2CO2NH4) leaching to recovery manganese from steel plant slag. This investigation showed that treatment of the slag in hydrogen prior to leaching enhanced manganese extraction. Up to 80 pct of the manganese and 50 pct of the iron could be extracted from a silicon steel slag that had been pretreated in hydrogen at 700 deg. C. Two 4-h leaching stages conducted at ambient temperature with a solution containing ammonia and carbon dioxide dissolved manganese and iron as their carbamate complexes. Heating the pregnant solution to 65 to 85 deg. C decomposed the complexes and precipitated the metals as insoluble carbonate salts. Ammonium carbamate leaching of other slags from several steelmaking plants produced lower manganese extractions, which suggests that the method cannot be applied satisfactorily to all steelmaking slags.
Manganese-compounds; Metal-compounds; Metal-refining; Steel-industry; Foundries; Carbamates; Chemical-processing; Chemical-extraction
Report of Investigations
NTIS Accession No.
Reno, NV: U.S. Department of the Interior, Bureau of Mines, RI 9400