78results about "Tungsten compounds preparation" patented technology

The invention relates to a process for reclaiming a honeycomb SCR waste catalyst. The process comprises the following steps: grinding a waste catalyst, adding water to wash dust and impurities, drying and grinding, leaching under pressure at a high temperature, separating solid and liquid to obtain filter residues and an extraction solution, mixing the filter residues with hydrochloric acid and water, and calcining after the reaction to prepare rutile titanium dioxide; regulating the pH of the filtrate, and carrying out ion exchange and resolving to obtain a mixed solution with high content of ammonium paratungstate and ammonium metavanadate; regulating the pH of the mixed solution, adding ammonium salt, regulating the temperature, precipitating and crystallizing to obtain ammonium metavanadate crystal, separating solid and liquid, and evaporating and crystallizing the filtrate to obtain ammonium paratungstate crystal. The process adopts the ion exchange method to replace an extraction method and is easy to operate; the prepared product has high quality and high reclaiming rate, does not need high temperature or pressure, and is low in energy consumption and low in cost; tungsten, titanium and vanadium in waste catalyst can be effectively reclaimed, wastewater can be recycled or discharged up to standard, and the environmental risk is small.