KR20030054033A - Method for manufacturing the blending material for the sintering process - Google Patents

Abstract

PURPOSE: A method for manufacturing blending raw materials for sintering operation is provided to improve productivity of sinter ore by greatly improving granulation property of high crystal water iron ore having high porosity without addition of water to improve granulation property in the process of granulating sintering raw materials including high crystal water iron ore having a relatively higher porosity. CONSTITUTION: The method comprises steps of storing sintering raw materials consisting of fine iron ore including high crystal water iron ore having 3% or more of crystal water content, subsidiary raw materials such as limestone and silica stone, and coke into raw material storage bin(13); feeding a fixed amount of the sintering raw materials from the raw material storage bin; and mixing the fed sintering raw materials in mixer(14), and granulating the mixture in granulator(15) by adding water to the mixture, wherein the surface of the high crystal water iron ore is treated with polymer acryl amide based compound, wherein the surface of the high crystal water iron ore is treated with polymer acryl amide based compound by spraying a polymer acryl amide aqueous solution prepared by dissolving the polymer acryl amide based compound into water onto the high crystal water iron ore, and wherein concentration of the polymer acryl amide aqueous solution is maintained to 0.005 to 0.5%.

Description

Method for manufacturing the blending material for the sintering process

The present invention relates to a method for producing a blended raw material for producing a sintered ore for blast furnace by mixing and assembling sintered raw materials such as fine iron ore raw material and fuel, more specifically 3% or more of the crystal water content poor granulation The present invention relates to a method for producing a blended raw material for the sintering industry, which manufactures a blended raw material by mixing and assembling a sintered raw material including a high crystallized iron ore having an iron oxide.

Generally, sintered ore in steelworks uses 70-80% of sintered ore as iron raw material. The sintered ore is produced by a sintering process in which a blended raw material is charged into a sintering bogie of a sintering machine and burned by an ignition furnace. At this time, referring to FIG. 1, the blending raw material 7 in which various raw materials such as fine iron ore, limestone as a subsidiary material, and fine powder coke as a fuel is blended is rotated from the charging hopper 6 by rotation of the drum feeder 8. It is dispensed to the charging chute 5 via the hopper gate. Then, the compounding raw material 7 discharged by the operation of the charging chute 5 is charged into the sintering cart 1 of the sintering machine.

Then, the surface of the raw material layer of the blended raw material charged in the sintered trolley 1 is ignited by the ignition burner 4, and the coke contained in the raw material layer is combusted by air sucked downward by a suction blower (not shown). Produces a sintered ore. Reference numeral 10 is a top light of relatively coarse particles charged under the sintered trolley 1, and reference numeral 12 is a light distribution part through which the sintered light is discharged.

On the other hand, sintered raw materials include various iron ore of about 10 mm or less, CaO-containing raw materials such as limestone and quicklime, which are usually smaller particle sizes, SiO ₂ containing raw materials such as silica and serpentine, and solid fuels such as coke and anthracite It is composed. These sintered raw materials are cut out by a predetermined amount in the raw material storage bin 13 according to the blending ratio determined in consideration of the quality and composition of the sintered ore in the after-assembler (15) mixed primarily in the mixer (14) Assembled under water supply.

On the other hand, a high speed stirring mixer, a pelletizer, or a drum mixer is used to mix and assemble the sintered raw materials. The high speed stirring mixer is used to improve the homogeneous mixing of the sintered raw materials in the case where there is a very small amount of sintered raw materials, and the pelletizer is used to improve the assemblability of the sintered raw materials. And when the sintered ore production is small, only one mixer is used.

In the assembly process, the blended raw materials are moistened about 6-8% depending on the type and characteristics of the blended raw materials. That is, when water is added in the granulator 15, fine particles having a particle size of about 0.25 mm or less are attached to nuclear particles having a particle size of about 0.5 mm or more, or fine particles are coarsely bonded to each other by surface tension of water. It forms a blended material of pseudo-particles.

It is known that the size and strength of pseudoparticles are reduced when there are many intermediate particles having a particle size of about 0.25 to 0.5 mm in such a blended raw material.

On the other hand, the quicklime added to the blended raw material is known to increase the surface tension of water to improve the assembly properties of the sintered raw material, that is, the size and strength of the pseudo particle.

In addition, as the size of the pseudo-particles produced in the granulation process as described above increases, the voids between the sintered raw materials are developed, so that the air permeability is improved in the raw material layer of the blended raw materials charged in the sintered trolley, so that the gas flow smoothly when the air is sucked downward. Therefore, the time required for the combustion of the blended raw material and the melting zone to reach the lower part of the sintered bogie is shortened, thereby increasing the productivity of the sintered ore and generating secondary hematite, which is generated during the sintering reaction and acts as a cause of the low temperature reduction of the sintered ore. Decrease.

That is, the granulation of the sintered raw material in the sintering process has a great influence on the sintered ore productivity and quality.

However, when assembling a sintered raw material containing high crystallized iron ore containing crystalline water, the granularity of the sintered raw material is relatively lowered. This is because the high crystalline iron ore has a relatively high porosity compared to hematite, a considerable amount of water added in the assembling process of assembling the sintered raw material containing the high crystalline iron ore is absorbed into the pores of the high crystalline iron ore. As a result, the amount of moisture that adheres and binds the fine ore to each other on the surface of the sintered raw materials is reduced, resulting in poor assembly of the sintered raw materials.

In addition, since sintered raw materials containing high crystallized iron ore are mixed and the size of the assembled pseudo-particles is reduced, eventually, the air permeability of the raw material layer is deteriorated in the sintering machine sintered using such sintered raw materials. Low-temperature reduction differentiation is also worse.

On the other hand, in order to improve the assemblability of the sintered raw materials containing high crystallized iron ore, considering the amount of moisture absorbed into the pores of the high crystallized iron ore, the amount of water supplied to the granulator is increased, but in this case it is added in the sintering process A large amount of heat is required to evaporate the moisture in proportion to the amount of moisture. Therefore, in order to satisfy this, more expensive fuel such as coke is required, and moisture evaporated during the sintering process is condensed again under the sintered layer so that the air permeability of the sintered layer is deteriorated, thereby lowering the productivity of the sintered ore.

The present invention has been made to solve the conventional problems as described above, porosity without adding more moisture in order to improve the assemblability in the assembly process of the sintered raw material containing high crystallized iron ore having a relatively high porosity It is an object of the present invention to provide a method for producing a blended raw material for the sintering industry which can greatly improve the assemblability of the high-crystallized iron ore, thereby improving the productivity of the sintered ore.

1 is an overall structural diagram of a typical sintering machine;

2 is a perspective view of a sintering machine sintering cart;

Figure 3 is a block diagram showing the process of cutting, mixing and assembling the sintered raw material.

<Description of Symbols for Major Parts of Drawings>

13: raw material storage bin

14: Mixer

15: assembly machine

In order to achieve the above object, according to the present invention, the method for producing a blended raw material for the sintering industry is made of fine raw materials such as iron ore, limestone and silica and fine coke containing fine crystal water iron ore having a crystal water content of 3% or more Storing the sintered raw material in a raw material storage bin, quantitatively cutting the sintered raw material from the raw material storage bin, mixing the sintered raw material which is cut out in a mixer and assembling in a granulator under water addition, The surface of the purified iron ore is characterized in that the surface is treated with a polymer acrylamide compound.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention, the same configuration will be assigned the same reference numerals.

In order to prepare a blended raw material for the sintering industry, first, a fine iron ore containing high crystallized iron ore having a crystallized water content of 3% or more, subsidiary materials such as limestone and silica, and sintered raw materials such as coke are stored in the raw material storage bin (13). Store in The sintered raw material quantified from the raw material storage bin 13 by the operation of the quantitative cutting device is mixed in the mixer 14 and assembled in the granulator under the addition of moisture.

At this time, according to the present invention, the high crystal water iron ore is pretreated with a relatively high viscosity aqueous acrylamide solution before being cut out from the raw material storage bin (13). When the aqueous polymer acrylamide solution is sprayed on the surface of the high crystalline iron ore, the aqueous polymer amide amide sprayed through the pores formed on the surface of the high crystalline iron ore is absorbed to block the absorption of moisture through the pores.

That is, when water is added to the high crystalline iron ore having a relatively high porosity, moisture formed on the surface of the high crystalline iron ore is quickly absorbed through the pores, but when a highly viscous aqueous solution is sprayed onto the high crystalline iron ore, The aqueous solution is not completely penetrated into the pores and is adsorbed only a small amount near the surface of the pores to close the pores.

The polymer acrylamide aqueous solution is obtained by dissolving the polymer acrylamide compound in water. The polymer acrylamide compound has a relatively high molecular weight and has the property of increasing the viscosity of the aqueous solution even if it is slightly dissolved in water. Therefore, spraying a relatively high viscosity aqueous acrylic acrylamide solution on the surface of the high crystal water iron ore closes the pores formed on the surface of the high crystal water iron ore as described above.

Since the pre-treated high crystal water ore contains the water of the high viscosity aqueous solution, the sintered raw material containing such high crystal water ore is mixed in the mixer 14 and added during the granulation process in the granulator 15. Keeping the added amount of water low by about 5% can increase the pseudo particle size of the blended ingredients.

Sintered raw materials containing high-crystalline water iron ore according to the present invention pre-treated using an aqueous polymer acrylamide solution and conventional high-crystalline water iron ore which were not pretreated are charged into a sintering bogie and then sintered. According to the present invention, the air permeability of the raw material layer of the blended raw material containing high crystallized iron ore is greatly improved, thereby greatly shortening the sintering time and greatly improving the sintered ore productivity.

The polymer acrylamide compound is a nonionic material represented by the formula [(CH ₂ CHCONH ₂ ) _n ], and mainly composed of C, H, O, N materials. There is no fear that the materials generated will corrode the sinter plant and the nitrogen contained in the acrylamide is not converted to environmentally harmful nitrogen compounds (NOx).

Polymeric acrylamide compounds are classified as cationic or anionic depending on the substance to be added, and have a characteristic of changing the degree of dissolution in water and the viscosity of the aqueous solution since the molecular weight varies.

On the other hand, when the aqueous solution concentration of 0.005% of the aqueous solution of the acrylamide of the nonionic polymer having a molecular weight of about 10000x10 ³ was sprayed on the surface of the high crystallized iron ore, it showed little effect on the granulation of the sintered raw material. And when the aqueous solution of acrylamide solution concentration of 0.5% or more is sprayed on the surface of the high crystal iron ore, the viscosity of the water is increased very high, but the acrylamide is not homogeneously dissolved in the water, and the aqueous solution is the surface of the high crystal iron ore. It is not easy to spray on homogeneously. Therefore, it is preferable to maintain the aqueous solution concentration of acrylamide at 0.005 to 0.5%.

As described above, the aqueous solution of acrylamide is sprayed on the surface of the high crystallized iron ore to close the pores formed on the surface of the high crystallized iron ore, so that the sintered raw material containing the pretreated high purity iron ore is mixed and added with water. In the case of granulation under the other conditions, the other materials adhere well to each other by suppressing the water absorption by the pores and by the relatively high surface tension of the aqueous solution. This improves the productivity of the sintered ore.

Hereinafter, the manufacturing process of the compounding raw material for sintering industry according to the present invention.

Example 1

Referring to Table 1 below, the blending ratio of the sintered raw materials used in the sintering test operation can be seen.

TABLE 1

hematite magnetite High Crystalline Iron Ore Limestone Serpentine burr quicklime sum 37 3 40 15.1 2.5 One 1.4 100

As shown in Table 1, the sintered raw material contains 40% high crystallized iron ore. At this time, the high crystal water iron ore is surface treated with a polymer acrylamide aqueous solution. Polymers of acrylamide solution is obtained by a molecular weight of the molten 10000x10 ³ of non-ionic acrylamide-based compounds _{[(CH 2 CHCONH 2) n} ] in water. And the aqueous solution concentration of acrylamide was kept at 0.03%.

At this time, the sintered raw material is divided into a first sample containing a high crystallized iron ore surface treated with an acrylamide aqueous solution and a second sample containing a high crystallized iron ore not surface treated with an acrylamide aqueous solution. This sintered raw material is mixed and then granulated under water addition. The moisture content of the sintered raw material was kept about 5% lower than that of the usual granulated water content.

After completion of the assembly, a portion of each of the first sample and the second sample was taken to measure the pseudo particle size of the blended raw material. As a result, it can be seen that the average particle size of the pseudo particle of the first sample is increased by about 0.5 mm compared to the average particle size of the pseudo particle of the second sample.

Table 2 shows the results of sintering the blended raw material of the first sample in a sintering test simulator.

TABLE 2

Port diameter 240 mm After Sintered Layer 500 mm Ignition temperature 1100 ℃ Ignition time -2 minutes Initial Underpressure in Sintered Layer 1500 mmH ₂ O

In Table 2, the ignition time is a time showing the difference based on the reference ignition time required when sintering the blended material of the second sample. Therefore, as shown in Table 2, the sintering time used when sintering a sintered raw material having a high crystallized iron ore surface-treated with an aqueous polymer acrylamide solution in accordance with the present invention is not a surface-treated high-crystalline water iron ore It can be seen that the sintered raw material having a sintered raw material has been shortened by 2 minutes compared to the standard sintering time used.

In addition, as a result of comparing the measured values of the low temperature reduction differentiation characteristics of the sintered ore of the first sample and the sintered ore of the second sample, the sintered ore of the first sample according to the present invention was treated with the surface of the high-crystalline water iron ore with a polymer acrylamide aqueous solution. The low temperature reduction differentiation index was found to be about 4 times lower than the low temperature reduction differentiation index of the sintered ore of the second sample in which the high crystallized iron ore was not treated with the polymer acrylamide solution, and the productivity and quality of the sintered ore were improved.

According to the present invention, by spraying a high viscosity aqueous acrylic amide aqueous solution on the surface of the high crystal iron ore by surface treatment, by blocking the absorption of moisture through the pores formed on the surface of the high crystal iron ore, the granulation is good It is possible to produce a blended raw material which can improve the productivity and quality of the sintered ore.

The foregoing is merely illustrative of the preferred embodiments of the present invention and those skilled in the art to which the present invention pertains recognize that modifications and variations can be made to the present invention without departing from the spirit and gist of the invention as set forth in the appended claims. shall.

Claims (3)

In the method for producing a blended raw material for sintering industry, Storing a sintered raw material consisting of coke and co-coated sintered raw materials including fine ore iron ore, limestone and silica, including high-crystallized iron ore having a crystalline water content of at least 3%; Quantitatively cutting the sintered raw material from the raw material storage bin; The sintered raw material to be cut is mixed in a mixer and assembled in a granulator under water addition, The surface of the high crystal water iron ore is a surface-treated with a polymer acrylamide compound compound raw material manufacturing method for sintering. The method of claim 1, The surface of the high crystal water iron ore is surface treatment by spraying a polymer acrylamide aqueous solution in which the polymer acrylamide compound is dissolved in water. The method of claim 2, A method for producing a blended raw material for sintering industry, characterized in that the aqueous solution concentration of the polymer acrylamide is maintained at 0.005 ~ 0.5%.