NIOSHTIC-2 Publications Search
Chemical Processing of Hardface Alloy Grinding Waste.
2nd Int'l Symp --recycling of Metals & Engineered Materials TMS PP 171-184 :171-184
The U.S. Bureau of Mines has investigated technology to recover critical metals from hardface alloy grinding waste, a form of superalloy scrap. This report describes a hydrometallurgical process for the recovery of values such as cobalt, chromium, manganese, nickel, and tungsten. The process involved deoiling the grinding waste, followed by chloride-based dissolution of the deoiled material. A high-grade calcium tungstate product was recovered from the resultant leach residue. Iron, cobalt, manganese, and nickel chlorides were sequentially recovered from the leach liquor by solvent extraction. Market-grade cobalt chloride, manganese chloride, and nickel chloride products can be produced directly from the strip liquors; the final raffinate, a relatively pure chromic chloride solution, compared favorably with commercial solutions. An economic evaluation for a plant processing 455 kg/day of deoiled grinding waste is presented.
2nd Int'l. Symp.--recycling of Metals & Engineered Materials. TMS, PP. 171-184