Strengthened ammonia injection denitration method based on surface catalytic performance of iron ore pellets

Abstract

The invention relates to a strengthened ammonia injection denitration method based on surface catalytic performance of iron ore pellets. The method comprises the following steps of preparing green pellets by ingredients, drying and preheating a chain grate machine, and configuring ammonia injection denitration operation at an air draft drying section of the chain grate machine. The method is characterized by 1) determining pellet raw materials and a basic binder; 2) preparing a composite binder; 3) preparing green pellets with strong catalytic surfaces containing the composite binder; and 4) strengthening ammonia injection denitration on a pellet surface layer, decomposing and volatilizing the composite binder in a drying process to form rich pores in the pellet surface layer, increasing adsorption of NH3 and NOx on the pellet surface layer, accelerating a denitration reaction speed of the strong catalytic surface layer, and realizing strengthened ammonia injection denitration of thepellet surface layer. The method has advantages that a denitration rate is improved by more than 15 percent points compared with that of an existing ammonia spraying denitration technology; a pelletizing process does not need to be greatly changed, and only some improvements need to be made in the process of preparing the green pellets from the ingredients; and implementation and popularization are easy.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgical pellet technology, relates to the technical field of flue gas denitrification of iron ore pellets, and in particular relates to an enhanced ammonia injection denitrification method based on the surface catalytic performance of iron ore pellets. Background technique [0002] Nitrogen oxides (NOx) are the main substances that form acid rain, photochemical smog, haze weather and destroy the ozone layer, and their emissions pose a great threat to the ecological environment and human health. NOx emitted by the iron and steel industry accounts for 6% of the country's total emissions, and is an important source of air pollution. Iron ore sintering and pelletizing are the raw material processing links in the iron and steel process, and the flue gas NOx emitted ranks first among iron and steel enterprises, accounting for more than 50%. [0003] Pellets have many advantages such as hig...

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Problems solved by technology

[0007] Aiming at the low efficiency of denitrification by spraying ammonia in the air drying section of the pellets, the purpose of the present invention is to provide an enhanced ammonia spray denitrification method based on the catalytic performance of the surface of iron ore pellets. The strong catalytic surface layer of the binder improves the catalytic performance of the pellet surface and increases the denitrification reaction surface, and enhances the denitrification efficiency of ammonia injection in the air drying section

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