Fine iron pre-reduction technology suitable for wide grain size distribution and apparatus thereof

Abstract

The invention relates to a prereducing technology of iron powdered ore suitable for wide particle size distribution, which comprises the following steps: a) the iron powdered ore with particle size smaller than 8mm is added into a cylindrical fluidized bed from a bin and coal gas is introduced from the bottom of the cylindrical fluidized bed; the temperature in a reactor is 650 to 950 DEG C, pressure is 0.2 to 1.0Mpa and gas speed in the cylindrical fluidized bed is 3 to 25m / s; b) the iron powdered ore with particle size smaller than 0.5mm leaves the cylindrical fluidized bed along with the coal gas and enters a pyramid type fluidized bed at the upper part, the iron powdered ore is separated from the coal gas and back mixed to the lower part of the fluidized bed, while the iron powdered ore with the particle size smaller than 0.05mm enters a hot cyclone separator along with the coal gas for separation and returns to the fluidized bed or enters a next fluidized bed reactor; and c) the iron powdered ore after reaction enters the next fluidized bed reactor or a melting gasification furnace. In the technology of the invention, the layering of the iron powdered ore with various particle sizes in the fluidized bed can obtain high-quality fluidizaton, thus improving the chemical reaction kinetics conditions in the fluidized bed reactor and the reaction efficiency of the fluidized bed.

Description

technical field [0001] The invention relates to a smelting reduction ironmaking process in the field of ironmaking, in particular to a fine iron ore pre-reduction process suitable for wide particle size distribution and a device thereof. Background technique [0002] Pre-reduction of fine iron ore for sintering with a particle size of <8mm in a multi-stage fluidized bed is one of the main pre-reduction processes of the two-step smelting reduction ironmaking process. For the fluidized reduction process of fine iron ore for sintering with a particularly wide particle size distribution (the maximum particle size is 8 mm, and the minimum particle size is <0.1 mm), the fluidization quality in the traditional cylindrical fluidized bed reactor is poor, and there are a large number of Separation of fine iron ore with smaller particle size. Cylindrical fluidized bed is a commonly used fluidized bed type. It has simple structure, easy manufacture, and high utilization rate of e...

AI Technical Summary

Problems solved by technology

However, in a single conical fluidized bed reactor, for raw materials with a wide particle size distribution, it is difficult for a single conical fluidized bed to meet the high-quality fluidization requirements, and if factors such as the total height of the fluidized bed are considered, the conical fluidized bed It is also very difficult to design highly

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