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Separation and Recovery of Metals from Zinc-treated Superalloy Scrap.
Laverty-PD; Atkinson-GB; Desmond-DP
MISSING :16 pages
The U.S. Bureau of Mines treated mixed and contaminated superalloy scrap by pyrometallurgical and hydrometallurgical methods to separate and recover metal values. Best results were obtained by leaching zn-treated or atomized scrap with hcl-o2 at 95 deg c and 50 psig o2. This resulted in dissolving approximately 98 pct of the al, CO, cr, cu, fe, mn, ni, and zn while rejecting over 98 pct of the mo, Nb, ta, ti, w, and zr as an insoluble refractory residue. Chlorine was successfully substituted for hcl to leach zn-treated scrap but was unsuccessful for leaching atomized scrap. The leaching solution was treated by ph adjustment and hydrothermal precipitation at 200 deg c for 4 h to remove al, cr, fe, and other contaminants as a filterable precipitate. Recovery of CO and ni would be accomplished by solvent extraction and electrowinning. Chromium recovery as a ferroalloy was demonstrated.
IH; Report of Investigations;
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division