The invention belongs to the technical field of
hematite denitration, and particularly relates to a method suitable for middle denitration of superfine
hematite pellets, which comprises the following steps: (1) controlling the high-point temperature of
flue gas of a catalyst layer of a denitration
tower to be 390-400 DEG C; (2) the high-point temperature of a preheating second-section air bellow of the chain grate
machine is controlled to be 550-590 DEG C; (3) increasing the
air volume of a backheating fan; (4) the temperature of an inlet of a main exhaust fan is controlled to be 140-150 DEG C, and the negative pressure of a
kiln tail is controlled to be 220-260 Pa; (5) increasing the distribution thickness of the south side and the north side of the chain grate
machine, controlling the distribution thickness to be 190 + / -10mm, and controlling the thickness difference between the south side and the north side to be + / -5mm; (6) a first air bellow
branch pipe of the first preheating section of the chain grate
machine is connected to a regenerative horizontal
pipe of the second preheating section of the chain grate machine; (7) adjusting a float flowmeter according to the
nitrogen oxide content of the original
flue gas at the inlet of the south-north denitration
tower, increasing the
ammonia spraying amount of the south-side denitration
tower, and reducing the
ammonia spraying amount of the north-side denitration tower; and (8) the emission of
nitric oxide is controlled in a centralized
control mode, and the emission is controlled to be 20-30 mg / Nm. By adopting the method,
ammonia escape is reduced, the temperatures of the first preheating section and the second preheating section are controlled, and the denitration efficiency is improved.