Pulverized coal melt separation and recovery method for low-grade iron resources

Abstract

The invention relates to a pulverized coal melt separation and recovery method for low-grade iron resources and belongs to the technical field of ferrous metallurgy and environment protection. The pulverized coal melt separation and recovery method for low-grade iron resources comprises the steps that pulverized coal, raw materials containing iron and a fluxing agent are mixed to prepare carbon-containing pellets and are directly reduced rapidly; the metallized pellets are hot-charged in a melt separation furnace; heat required by melt separation is provided by hot air blown in from an air port and through combustion of hot coal left in the metallized pellets, and separation between slag and iron and recovery of iron are completed. The pulverized coal melt separation and recovery method for low-grade iron resources has the advantages that the heat utilization rate is increased, use amount of coke is reduced during melt separation, and energy consumption and production cost are reduced. Due to the fact that metallurgical solid waste and low-grade iron ore are high in slag content and low in iron grade, it is not economical if a traditional blast furnace technique is used for recovering iron; due to the fact that no coke layer exists in a traditional coal-based melt separation technique, molten iron carburization is not sufficient; in addition, due to the fact that the heat conductivity coefficient of a slag layer is low, iron melting is difficult. By the adoption of the technique, the high temperature and the high heat utilization rate which are required by molten iron melting are guaranteed; the technique is suitable for processing low-grade resources containing iron, and the current utilization situation of metallurgical solid waste and low-grade ore is greatly changed.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy and environmental protection, and in particular relates to a coal powder melting recovery method for low-grade iron resources, which is suitable for recycling low-grade metallurgical solid waste and iron elements in iron ore. Background technique [0002] 97% of the domestic copper output is obtained through pyrometallurgy, and the copper slag output per ton of copper is about 2.2t, resulting in a huge copper slag output. The iron grade in copper slag is generally 30-40%, and contains 0.5-2% copper. About 6-16 tons of nickel slag is produced by flash furnace smelting 1 ton of nickel. Jinchuan Nonferrous Metals Company produces about 800,000 tons of nickel slag every year, most of which are accumulated. The iron content in nickel smelting waste slag is equivalent to that of copper slag, and the nickel content is about 0.2-0.7%. In addition, it also contains a certain amount of va...

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Problems solved by technology

Therefore, this kind of non-ferrous metallurgy solid waste has a high recycling value. Discarding it will not only cause waste of resources, but also occupy a large amount of land and cause environmental pollution.

In addition, the grade of iron ore in my country is generally low, and it can only be put into the furnace after beneficiation and sintering into pellets. The process is long and the energy consumption is high. Non-blast furnace ironmaking is a reasonable way to deal with low-grade iron resource ores.

[0003] At present, there are various coal-based non-blast furnace ironmaking processes, the fundamental purpose of which is to avoid the utilization of coke, but due to the low thermal conductivity of the slag layer, there is no heat conduction effect of the coke layer, resulting in low thermal efficiency

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