Method for reinforcing sintering of iron ores difficult to pelletize by biomass fuel

Abstract

The invention relates to a method for reinforcing the sintering of iron ores (vanadic titanomagnetite, specularite, secondary iron-containing resources and the like) difficult to pelletize by biomass fuel. By applying the biomass fuel with high burning velocity to the sintering of the iron ores difficult to pelletize, the sintering speed and the utilization coefficient can be improved. The reinforcing method comprises the following steps of: adding 1 to 4 percent of biomass fuel into a sinter mixture containing the iron ores difficult to pelletize, wherein the biomass fuel is required to have 65 to 85 percent of content of fixed carbon, 10 to 25 percent of volatile matter, more than 24 to 30MJ / kg of calorific value, 40 to 60 percent of porosity, 10 to 100m2 / g of specific surface area and 1 to 4mm of average particle size; after weighing the iron ores difficult to pelletize, a flux, sintering return fines and the biomass fuel according to the weight ratio, sufficiently mixing the raw materials and pelletizing; distributing the mixture, igniting and sintering to obtain agglomerates. After the biomass fuel is adopted to reinforce the sintering of the iron ores difficult to pelletize, the sintering speed can be improved by 2 to 5mm / min, the utilization coefficient can be improved by 0.2 to 0.4t / (m2.h) and meanwhile, low intensity variation of an agglomerate revolving drum is ensured.

Description

technical field [0001] The invention belongs to the field of iron ore sintering, and relates to a method for strengthening the sintering of refractory iron ore such as vanadium-titanium magnetite, specularite and secondary iron-containing resources by using biomass fuel. Background technique [0002] In recent years, my country's iron and steel industry has developed rapidly, and the steel output in 2010 has reached 627 million tons. Iron and steel production requires a huge amount of iron ore. In 2010, my country imported 620 million tons of iron ore, and its dependence on imports was as high as 63%. my country's iron ore resources are increasingly scarce, and high-grade hematite and magnetite resources with excellent sintering properties are continuously decreasing, while specularite, vanadium-titanium magnetite, and secondary iron-containing resources are poor in granulation performance. To ensure the quality of sintered ore, it is generally restricted during use. [000...

AI Technical Summary

Problems solved by technology

Secondary iron-containing resources such as iron-containing dust, waste slag, and sediment produced in the iron and steel industry, acid-making enterprises, and non-ferrous smelting industries are mostly man-made ores. After a high-temperature process, the surface of the particles is smooth and the water absorption is poor. The material will deteriorate the air permeability of the sintered material layer and affect the technical and economic indicators of sintering. Generally, the dosage is not high and the utilization rate is low.

[0006] The common feature of vanadium-titanium magnetite, specularite and secondary iron-containing resources is that the granulation performance is poor, resulting in poor air permeability of the sintered material layer, which makes the amount of air passing through the material layer insufficient, and deteriorates the combustion of fuel in the sintered material layer. Slow vertical sintering speed and low utilization factor

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