Method for reducing sintering energy consumption of high limonite

Abstract

The invention discloses a method for reducing sintering energy consumption of high limonite, and relates to the technical field of ferrous metallurgy, and the method comprises the following steps: mixing an iron-containing material, a flux and return mine, and granulating to obtain a mixture; uniformly dividing the mixture into a plurality of parts; mixing each part of the mixture with fuel to form a sintered raw material; the sintering raw materials are sequentially distributed and stacked and sintered to form sintered ore, and the adding proportion of fuel in the multiple layers of sintering raw materials is sequentially increased from bottom to top. The sintering technology of fuel layered addition is adopted, the distribution of fuel in a material layer is changed, the heat distribution of the material layer is optimized, the fuel consumption of sintered solids is reduced, meanwhile, the hot-state air permeability of the sintered material layer is greatly improved, and the quality of sintered ore is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of iron and steel metallurgy, and particularly to a method for reducing the sintering energy consumption of high limonite. Background Art

[0002] In the sintering production process, sintering is a process in which powdered iron-containing raw materials, fuels, and fluxes are mixed evenly in a certain proportion, ignited and sintered on a sintering device, so that a series of physical and chemical changes occur under the action of high temperature, and finally the iron ore powder particles are bonded into blocks under the condition of incomplete melting. As the main raw material for blast furnace smelting, the quality of sinter directly affects the smelting efficiency, production cost, and environmental emissions of the blast furnace.

[0003] In recent years, with the rapid development of the iron and steel industry globally, the increasingly tight iron ore resources have become an important factor restricting the development of iron and steel enterprises. The extensive use of limonite as the iron-containing raw material for sintering in sintering production has become the main means for major steel mills to reduce costs and is also an inevitable trend in the iron and steel industry. Limonite has high burn-off, high silicon content, low iron grade, and poor sintering performance. Therefore, it is necessary to solve the adverse effects of a large amount of limonite on the sintering economic and technical indicators. Due to the characteristics of limonite such as high crystal water content, coarse particle size, loose and porous structure, easy melting, high burn-off, and high reducibility, adding limonite to sintering will cause problems such as low sinter yield, poor strength, poor bed permeability, and high solid fuel consumption. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for reducing the sintering energy consumption of high limonite.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows: A method for reducing the sintering energy consumption of high limonite, comprising: Mixing limonite, flux, and return fines and granulating to obtain a mixture; Dividing the mixture into several portions; Mixing each portion of the mixture with fuel to form sintering raw material; Stacking and sintering the sintering raw material in sequence to form sinter, and the addition ratio of fuel in several layers of the sintering raw material increases sequentially from bottom to top.

[0006] As a preferred embodiment of the method for reducing the sintering energy consumption of high limonite according to the present invention, wherein: the flux includes one or more of dolomite powder, limestone, and quicklime.

[0007] As a preferred embodiment of the method for reducing the sintering energy consumption of high limonite according to the present invention, wherein: the mixture is divided into three portions.

[0008] As a preferred embodiment of the method for reducing the sintering energy consumption of high limonite in the present invention, among the three layers of the sintering raw materials, the proportion of fuel added to the sintering raw material located at the upper layer is 40-50%, the proportion of fuel added to the sintering raw material located in the middle layer is 30-40%, and the proportion of fuel added to the sintering raw material located at the lower layer is 10-20%.

[0009] As a preferred embodiment of the method for reducing the sintering energy consumption of high limonite in the present invention, the proportion of limonite added is 50%-80% of the total mass of the raw materials.

[0010] As a preferred embodiment of the method for reducing the sintering energy consumption of high limonite in the present invention, the basicity of the sinter is 1.80-2.20.

[0011] The beneficial effects of the present invention are as follows: The present invention adopts a sintering technology with stratified fuel addition, changes the distribution of fuel in the material layer, optimizes the heat distribution in the material layer, reduces the sintering solid fuel consumption, and at the same time greatly improves the hot permeability of the sintering material layer and improves the quality of the sinter. Detailed implementation mode

[0012] To make the content of the present invention easier to be clearly understood, the following further detailed description of the present invention is made according to the specific implementation modes.

[0013] Improving limonite is one of the important ways to reduce costs and increase efficiency in the sintering process. However, limonite has large burn loss, high silicon content, low iron grade, and poor sintering performance. High-ratio limonite sintering has the characteristics of slow sintering speed, low sintering productivity, loose structure of the sinter cake, low finished product rate, and high solid fuel consumption.

[0014] Therefore, the embodiment of the present application provides a method for reducing the sintering energy consumption of high limonite, and this method specifically includes the following steps: Step S101: Mix the iron-containing materials, namely limonite, flux, and return fines, and granulate them to obtain a mixture.

[0015] Specifically, mix limonite, flux, and return fines first, and then place them in a cylindrical mixer for mixing and granulation to obtain a mixture.

[0016] Among them, the above-mentioned flux includes one or more of dolomite powder, limestone, and quicklime.

[0017] Step S102: Divide the mixture into several portions.

[0018] In this embodiment, the mixture is divided into three portions.

[0019] Step S103: Mix each portion of the mixture with fuel to form a sintering raw material.

[0020] Specifically, three portions of the mixture are mixed with fuels in different proportions to form green sintering materials. Among these three portions of green sintering materials, the addition proportions of the fuels are 40 - 50%, 30 - 40%, and 10 - 20% respectively.

[0021] Step S104: The green sintering materials are laid and stacked in sequence, and sintered to form sinter. The addition proportion of the fuel in several layers of the green sintering materials increases sequentially from bottom to top.

[0022] Specifically, the three portions of the green sintering materials are laid and stacked in sequence in the vertical direction. The addition proportion of the fuel in the green sintering material located above is 40 - 50%, the addition proportion of the fuel in the green sintering material located in the middle is 30 - 40%, and the addition proportion of the fuel in the green sintering material located below is 10 - 20%.

[0023] After the three portions of the green sintering materials are stacked, the sintering material layer is sintered to finally form sinter.

[0024] It should be noted that the addition proportion of limonite is 50% - 80% of the total mass of the raw materials, and the basicity of the formed sinter is 1.80 - 2.20.

[0025] The technical solution of this application first mixes limonite, flux, and return fines, then places them into a drum mixer for pelletizing to obtain the mixture. The mixture is divided into three portions and then mixed with fuels in different proportions. By adopting the technology of separate addition of fuels, the distribution proportion of fuels in each layer of the material layer is optimized, thereby effectively reducing the solid fuel consumption of high-limonite sintering.

[0026] In addition to the above embodiments, the present invention may also have other embodiments; all technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A method for reducing the energy consumption of high limonite sintering, characterized in that: Including: Mixing limonite, flux and return fines and granulating to obtain a mixed material; Dividing the mixed material into several portions; Mixing each portion of the mixed material with fuel to form green sintering material; Stacking the green sintering material in layers in sequence and sintering to form sinter, and the addition ratio of fuel in several layers of the green sintering material increases successively from bottom to top.

2. The method for reducing the sintering energy consumption of high limonite according to claim 1, wherein: The flux includes one or more of dolomite powder, limestone, and quicklime.

3. The method for reducing the sintering energy consumption of high limonite according to claim 1, characterized in that: The mixed material is divided into three portions.

4. The method for reducing the sintering energy consumption of high limonite according to claim 3, wherein: Among the three layers of the green sintering material, the addition ratio of fuel in the upper green sintering material is 40% - 50%, the addition ratio of fuel in the middle green sintering material is 30% - 40%, and the addition ratio of fuel in the lower green sintering material is 10% - 20%.

5. The method for reducing the sintering energy consumption of high limonite according to claim 1, characterized in that: The addition ratio of the limonite is 50% - 80% of the total mass of the raw materials.

6. The method for reducing the sintering energy consumption of high limonite according to claim 1, characterized in that: The basicity of the sinter is 1.80 - 2.20.