Formation And Performance Test Of Rare Earth Tailings-based Catalysts

At present,with the rapid development of China's comprehensive national strength,the environmental problems caused by the production and consumption of energy by heavy industry are becoming increasingly tense,mainly reflected in the atmospheric pollutants produced have seriously threatened the harmonious development of human society,especially the environmental deterioration caused by NOx.For the ecological environment deterioration caused by NOx at home and abroad to actively take the corresponding denitrification means for treatment,the application of a more mature method is the selective catalytic reduction method,for the selective catalytic reduction method,now need to find a low cost,efficient,stable,anti-sulfur denitrification catalyst.Baiyun obo is rich in rare earth tailings has the denitration active substance"special"metal oxide,so the tailings can be used as natural denitration catalyst,but tailings showed various elements in the process mineralogy,low grade lean,fine grain size and mineral phase turbulence noise four big characteristics,mineral embedded complex,difficult to mineral separation to make it fail to be fully used,resulting in the accumulation of tailings dam is close to two hundred million tons.This paper takes baiyun obo rare earth tailings powder as research materials,research how two different binder?aluminum dihydrogen phosphate solution and sodium silicate solution?on its forming as a result,and then adopt a new preparation method?mold molding in whole?according to the different proportion of forming the proportion of rare earth tailings base honeycomb denitration catalyst.Through a variety of performance tests,the results show that the formed rare earth tailing-based honeycomb denitrification catalyst is effective and feasible in various properties,which has laid a solid foundation and prospect for its application in the field of industrial flue gas denitrification in the future.The main conclusions are as follows:?1?Will adopt mold molding in whole baiyun obo rare earth tailings powder preparation of honeycomb denitration catalyst,overcome the catalyst powder molding original easy pulverization,easily broken,easy to peel,difficult to play a catalytic activity of the faults on real significance,it is both the advantages of high efficiency,high sulfur and high stability of new functional material,can meet the need of industrial application of flue gas denitration.?2?This paper takes baiyun obo rare earth tailings powder for flue gas denitration catalyst active substances,combined with thin diaspore powder for alumina carrier,clay and aluminium dihydrogen phosphate solution as the solid-liquid mixed binder,determines the optimum quality material mixing ratio for:rare earth tailings powder:thin diaspore powder:clay=2:4:3,forming the honeycomb denitration catalyst in optimum condition denitration activity as high as 88.6%.?3?Under the condition of stable mechanical properties,BET and SEM-EDS showed that the rare earth tailings,which were smaller and smooth than the surface,were transformed into irregular and porous honeycomb after forming.The two aluminum sources were roasted and melted into?-Al₂O₃ at 500?,leading to?-Al₂O₃live site exposure of the rare earth tailings and its denitrification performance was enhanced.Through XRD and TG after 500?air roasting honeycomb shape catalysts,rare earth tailings originally bastnaesite and magnetite characteristic peak disappeared,and the apparent weightlessness,because the content of bastnaesite less thermal decomposition for scarce CeO₂ is hematite and magnetite was completely oxidation,so the two failed to detect the mineral phase,cerium oxide and hematite has good capability of catalytic reduction of NOx,thermal decomposition weightlessness of CO₂ scour overall,formation of the internal stress increases the pore entrance.