Study on the performance of a hydrocyclone used for recycling the waste SCR catalyst

Abstract

The selective catalytic reduction (SCR) catalyst has been widely used for de-nitrification processes of flue gas from coal-fired power plants because of its high de-nitration efficiency and low operating cost. But the SCR catalyst will lose efficacy in few years and its discharge would cause pollutions. A 20 mm hydrocyclone was used to separate TiO2 from SiO2 for the recycling of waste SCR catalysts based on lab tests and the simulation with Fluent in this paper. Results showed that both the pressure drop and separation efficiency increased with the increase of feed flow rate, the pressure drop almost levelled off when the swirl number exceeded 15.49, and the Newton efficiency increased with the increase of the swirl number as well and reached 83 % at the swirl number of 16.3. The purity of TiO2 could reach 95.53 %.