Preparation method of blast furnace sludge pre-reduced pellet

Abstract

The invention provides a preparation method of a blast furnace sludge pre-reduced pellet. The blast furnace sludge pre-reduced pellet is prepared from the following raw materials in percentage by mass: 10-30% of blast furnace sludge, 3.5-10% of SiC powder, 60-85% of iron ore concentrate and 1.2-1.5% of bentonite. The preparation method comprises the following steps: uniformly mixing 20-30% of the total dosage of the bentonite with the blast furnace sludge and the SiC powder, respectively, and uniformly mixing the iron ore concentrate with 70-80% of the total dosage of the bentonite to prepare a mixture; in a pellet preparation process, firstly, preparing the mixture of the blast furnace sludge, the SiC powder and the bentonite to a pellet core; then, adding the mixture of the iron ore concentrate and the bentonite to continue the pellet preparation process; and wrapping a layer of dolomite accounting for 0.5-1.5% of the total mass of the raw materials on the formed pellet, and preparing the pre-reduced pellet according to a conventional production process. By adopting the preparation method provided by the invention, a large amount of blast furnace waste can be consumed, the roasting temperature of the pellet is reduced, the utilization proportion of non-magnetite concentrate is increased, and the finished product pellet is non-adhesive, good in metallurgical performance and beneficial to improving the blast furnace efficiency and reducing the coke ratio of a blast furnace.

Description

technical field [0001] The invention belongs to the technical field of ironmaking raw material production, and in particular relates to a method for preparing pre-reduced pellets of blast furnace gas mud. Background technique [0002] Blast furnace gas sludge is the product of the dust carried by the blast furnace gas during the ironmaking process, and it is the product obtained through wet or dry dust removal. It is one of the main solid emissions of iron and steel enterprises. The gas mud has small particle size and low density, and it is easy to float in the atmosphere after drying, and it is easy to form floating dust with complex components and great harm to human body in the air, causing harm to human body. At the same time, gas mud is also a valuable secondary resource. If it cannot be effectively treated and utilized, it will not only cause waste of resources, but also cause great pollution to the environment. The chemical composition of gas mud is relatively comple...

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Problems solved by technology

[0006] Although the above documents and patents adopt different methods, the core is to add carbon or add flux, but they cannot completely solve the problem of pellet bonding and pellet strength decline