Sustainable Mining and Metallurgy

Aiming at the problems such as low off-gas temperature, low catalyst activity, unreasonable setting of ammonia injection grid and unreasonable setting of catalyst powder blowing system of the SCR denitration system for the alumina high temperature roasting kiln off-gas under pre-heating condition for a certain company in Shandong, the reconstruction was carried out by taking measures such as adding temperature-raising burner for pre-heating process, using low-temperature catalyst, optimizing and modifying ammonia injection grid and ammonia injection system, rearranging catalyst powder blowing system, etc. After the reconstruction, the off-gas NO_x emission concentration was reduced from 100mg/Nm ³ to below 35mg/Nm ³, and the ammonia injection system operated stably, which have harvested good economic and social benefits.