This Phase I project will explore new methods for recovery of chromium from spent fluorination catalysts, which are hazardous solid wastes, with waste minimization. Preliminary investigation has shown them to be a mixture composed primarily of chromium (I and II), oxide, and chromium (III) fluoride. They have been rendered extremely inert in their use as high-temperature fluorination catalysts and resist conventional techniques to dissolve, oxidize, or reduce the contained chromium.Chemical & Metal Industries, Inc. has identified several promising routes for recovery of chromium from these spent catalysts. These routes are based on reported chromium chemistry and promising preliminary results from Chemical & Metal Industries' laboratories. Each potential route will be investigated thoroughly in Phase I, so that only the most technically and economical attractive process will be further developed in Phase II. The chromium will be recovered as either sodium chromate or chromium (III) chloride. Both of these compounds can serve as excellent intermediates for the manufacture of chromium (III) oxide catalysts, completing a recycle loop for the recovered chromium.Chromium oxide is used as the catalyst in the manufacture of many of the fluorocarbons currently entering the market since the phaseout of chlorofluorocarbons. The spent catalysts contain 48 to 60 percent chromium. This proposed project will work towards complete recovery of chromium from this significant secondary resource and will eliminate these materials as hazardous solid wastes. More than 500,000 pounds of spent catalyst, containing 250,000 to 300,000 pounds of chromium, are generated per year, and this rate is expected to increase. The chromium will be recovered in a form from which fresh fluorination catalyst can be produced.Supplemental
Keywords:small business, SBIR, hazardous waste, engineering, chemistry
