Influence of Impurity Dissolution on Surface Properties and NH 3 -SCR Catalytic Activity of Rare Earth Concentrate

摘要

Impurity removal and modification of rare earth concentrate powder were conducted by roasting weak acid-weak alkali leaching to obtain the active components of denitrification catalysts. NH 3 selective catalytic reduction catalyst samples were prepared by mixing and kneading with pseudo-γ-Al 2 O 3 boehmite as carrier. The results showed that the Ce 7 O 12 content in the active component samples increased and dispersed more evenly. The grain size of the samples was refined, the specific surface area increased, and the active sites exposed more. Ce coexists in the form of Ce 3+ and Ce 4+ . Fe coexists in the form of Fe 3+ and Fe 2+ , but Fe 3+ is abundant. Some Ce, La, Nd, Pr, Fe, Mn, and other components formed solid melts during preparation, which increased the synergistic catalytic effect. The denitrification efficiency of the catalyst sample was 92.8% under the conditions of reaction temperature 400 °C, NO content was 600 ppm, NH 3 /NO ratio was 1.5, and O 2 concentration was 4%.