| 摘要 |
Provided is a method for preparing high-purity cobalt nitrate crystals from Co/SiO2 waste catalysts. The method sequentially comprises the following steps: 1) calcining Co/SiO2 waste catalysts to be treated at 350 to 500 ℃ under the existence of air for 3 to 6 hours, grinding the Co/SiO2 waste catalysts into powder after cooling to the room temperature; 2) transferring the waste catalyst powder into a fluidized bed reactor and taking reduction reaction for 8 to 12 hours in mixed gas of H2 and N2; 3) adding the waste catalysts after the reduction reaction into excessive dilute nitric acid solution to be fully dissolved and filtering; 4) using alkali liquid for regulating the pH value of the obtained cobalt nitrate solution to 1.5, adding oxalic acid solution for reaction in the water bath of 25 to 80 ℃, regulating the pH value of the reacted solution to 1.5 by diluted alkali solution and filtering the hot solution to obtain cobalt oxalate precipitates; 5) after drying the cobalt oxalate precipitates, roasting the dried cobalt oxalate precipitates at the temperature of 550 to 650 ℃ for 4 to 8 hours; 6) dissolving the obtained cobalt oxide by dilute nitric acid solution and 7) evaporating and crystallizing the cobalt nitrate solution to obtain Co(NO3)2·6H2O crystals. The recovery rate and the purity of the Co(NO3)2·6H2O in the method are high. |
