Method and device for preparing fuel from sintered material

Abstract

The invention relates to a method for preparing fuel from a sintered material. The method comprises the following steps that a, screening is carried out, specifically, the fuel to be prepared is screened by a 0.5 mm square hole sieve, oversize products are put into a fuel bin, and undersize products are put into a small-particle fuel bin; b, primary ditching is carried out, specifically, primary ditching is carried out on an iron-containing material of a sintered material conveying belt, and quicklime is added into a primary ditch; c, secondary ditching is carried out, specifically, secondary ditching is carried out on the quick lime, and small-particle fuel is added into secondary ditches; d, water is added, and water is added on the quick lime; e, folding is carried out, specifically, the material surface is folded; and f, granulating is carried out, and the blended sintered material is granulated in a granulator. The method for preparing fuel from the sintered material has the beneficial effects that 1, the defects that gaps are blocked and the productivity is reduced in the sintering process of the small-particle fuel are overcome; 2, part of small-particle fuel is prevented from being sucked away by an exhaust fan, and the utilization rate of the fuel is improved; 3, the accuracy of the proportion of the fuel in the ingredients is ensured; and 4, the loss of heat generated during quick lime digestion is reduced.

Description

technical field [0001] The invention relates to a carbon distributing method and a fuel distributing device for improving the utilization rate of small-grained fuel, which belong to the technical field of iron and steel metallurgy. Background technique [0002] The sintering of iron ore powder in the metallurgical industry is to mix the iron-containing ore powder within a certain particle size range with the fuel and flux broken into small particles according to the pre-set alkalinity and the energy consumption of the material, and then mix them with water. , Granulation to form sintered ingredients. The sintering ingredients are evenly distributed on the sintering equipment according to a certain thickness. Through ignition and fan exhaustion, with the help of high temperature generated by fuel combustion and a series of physical and chemical changes between materials, some low-melting point substances are formed, and a certain amount of them are softened and melted. In th...

AI Technical Summary

Problems solved by technology

In the sintering process of iron ore powder, fuel is one of the indispensable materials. Coke powder and coal powder are usually used as fuel, and the combustion process of fuel depends on the particle size of coke powder or coal powder. If the particle size of the fuel is too coarse , the specific surface area is too small, the combination of fuel and oxygen is poor, the combustion speed is slow, and the thickness of the combustion zone is widened, resulting in poor air permeability of the sintered layer, and then the vertical sintering speed slows down, resulting in reduced productivity; It will cause relatively sparse and uneven distribution of fuel in the material layer, and aggravate the temperature difference between the upper and lower layers of the sinter layer, the quality of the sinter ore, and the low yield.

However, when the fuel particle size is too fine, the specific surface area increases, the fuel is easily dispersed in various parts of the material layer, and the burning speed is fast. When the heat transfer property of the sintered material is not good, the burning speed of the solid fuel cannot reach the high temperature and high temperature maintenance required for the melting of the material layer. If the high temperature reaction is too late, the sintering temperature will drop, the amount of liquid phase will be insufficient, the sinter binder phase will decrease, the strength of the drum will become lower, the powder will increase, the amount of returned ore will increase, and the productivity will decrease. Layer gaps hinder the movement of airflow, making the material layer poor in permeability, increasing the pressure difference, thickening the combustion zone, and reducing the output of sintered ore; and if the fuel is too fine, it is easy to be sucked away by the ventilation system, reducing the fuel utilization rate and increasing the fuel consumption. high

In view of this, in the normal production process, the fuel particle size is stipulated at <3mm and the proportion is controlled at 75-85%, but in this fuel particle size composition, there will be a large number of parts smaller than 0.5mm, generally around 15%, and the fuel is directly added to the powder In the material, and this particle size happens to be part of the fine particle size, the carbon utilization rate decreases during the sintering process, the fuel consumption increases, the gap is blocked, the productivity is reduced, and it is even sucked away by the ventilation system, resulting in waste of fuel.

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