Minerals (Apr 2019)

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

  • Kai Zhang,
  • Jinhao Zhu,
  • Shuning Zhang,
  • Na Li,
  • Huijuan Luo,
  • Baowei Li,
  • Zengwu Zhao,
  • Guang Jin,
  • Wenfei Wu

DOI
https://doi.org/10.3390/min9040246
Journal volume & issue
Vol. 9, no. 4
p. 246

Abstract

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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. NH3 selective catalytic reduction catalyst samples were prepared by mixing and kneading with pseudo-γ-Al2O3 boehmite as carrier. The results showed that the Ce7O12 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 Ce3+ and Ce4+. Fe coexists in the form of Fe3+ and Fe2+, but Fe3+ 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, NH3/NO ratio was 1.5, and O2 concentration was 4%.

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