Abstract: This article aims to research into the comprehensive utilization of spent catalyst, which offers a new process that takes the calcium oxide as the packing material and takes it into consideration that the influencing dissolved factors such as the roasting temperature, the roasting time, and the spent catalyst particle size. Three methods including chemical titration, spectrophotometry and pectrophotometry; atomatic absorption spectrometry（AAS）are used for the detection of the chromium and combalt in the spent catalyst and to establish the best experimental conditions. The experimental results indicate the optimum conditions are that the roasting temperature is 400 ℃, the roasting time is 4h, the spent catalyst granularity is 60mesh, the dissolution ratio is more than 98%. The best pH of EDTA Volumetric analysis of total combalt is 5-6 and the best pH of hydrogen peroxide of chromium is more than 10. The recommended method is convenient and feasible, but it has the lower accuracy and precision. The Spectrophotometric Spectrum follows the Lambalt Beer’s Law in conditions that the concentration of cobalt ions is 0-2.50mg/L and the concentration of chromium is within 0-0.20mg/L. The AAS shows a good linear relation between the absorbance and the concentration in conditions that the concentration of the chromium and combalt is within 0-2.0mg/L. The latter two methods have the advantages of high sensitivity, less interference, high selectivity and good repition.
Keywords：spent catalyst; roast; chemical titration; spectrophotometry; atomatic absorption spectrometry
