Low-concentration nitrogen pulverized coal conveying method for smelting reduction furnace

Abstract

The invention belongs to the field of ironmaking processes, and particularly relates to a low-concentration nitrogen pulverized coal conveying method for a smelting reduction furnace. According to thetechnical scheme, the low-concentration nitrogen pulverized coal conveying method for the smelting reduction furnace includes the following steps that firstly, pulverized coal enters a coal mill through a coal feeder to be coarsely ground, and the grain diameter of the pulverized coal ranges from 53 micrometers to 178 micrometers; the coarsely-ground pulverized coal is fed into a dryer generatorfrom the coal mill, and the pulverized coal is dried at the temperature of 110-130 DEG C for 2-4 hours; the dried pulverized coal is finely ground before being jet and fed into a coarse powder separator to be treated, and then passes through a pulverized coal vibrating screen, and the grain diameter of the pulverized coal ranges from 53 micrometers to 74 micrometers; and the finely-ground pulverized coal is jet to a coal spraying pipeline through a double-tank single pipeline under distribution of nitrogen, pulverized coal high-concentration and nitrogen low-concentration jetting is kept, andthe mass velocity of the pulverized coal ranges from 0.138 kg / s to 0.55 kg / s. By means of the method, the purpose of efficiently conveying the high-concentration pulverized coal in the low-concentration nitrogen environment can be achieved.

Description

technical field [0001] The invention belongs to the field of ironmaking technology, and in particular relates to a method for conveying pulverized coal with low-concentration nitrogen gas for a smelting reduction furnace. Background technique [0002] The iron bath smelting reduction method for smelting molten iron needs to inject a large amount of coal powder into the molten pool. The coal powder conveying process directly affects the stability of production, and is also one of the key technologies in the smelting reduction smelting molten iron system. However, it is difficult for traditional coal injection equipment to achieve the amount of pulverized coal required for the smelting reduction smelting process. Transport efficiency is low. An effective way to solve the above problems is to use high-concentration pulverized coal conveying technology, which can greatly reduce the cold air in the iron bath molten pool under the same condition of conveying powder, which will he...

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Problems solved by technology

[0003] In the current high-concentration pulverized coal transportation process, since the structure of the pulverized coal transportation pipeline is still relatively tortuous and complicated, when the conditions such as the pulverized coal mass flow rate or pulverized coal particle size are unreasonable, the pulverized coal will be stagnated inside the pipeline, or The phenomenon of uneven injection flow increases the emission of harmful gases after combustion, resulting in wasting resources and polluting the environment.

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