KR102033028B1 - Manufacturing method of sintered ore - Google Patents

Abstract

Assembling by adding moisture to the sintered blended raw material including a raw material, a fuel material and a secondary raw material; Preparing a mixed solution by mixing a binder and water containing a cellulose ether compound; Preparing agglomerated particles by spraying the mixed solution on the assembled sintered blend raw material; And a step of sintering the agglomerated particles. In the preparing of the mixed liquid, a sintered ore manufacturing method of mixing the binder and water such that the viscosity of the mixed liquid is 5000 to 20000 cps is introduced.

Description

MANUFACTURING METHOD OF SINTERED ORE}

The present invention relates to a method for producing a sintered ore excellent in breathability and excellent in combustion efficiency.

In general, the sintered ore manufacturing process is a process for manufacturing the sintered ore by processing the iron ore to be easy to use in the blast furnace. Coke, fuel, limestone, and subsidiary materials may be mixed with iron ore and then sintered to prepare a sintered ore.

The sintered ore manufacturing process may proceed in the following order. First, a raw material mixed with iron ore and fuel, coke and subsidiary materials is charged to a balance at a certain height. Then, when the upper layer of the raw material is ignited and air is forcedly sucked from the lower side, sintering of the raw material proceeds to produce a sintered ore.

Thereafter, the sintered ore having a particle size that is easy for charging and reaction in the blast furnace is transferred to the blast furnace, and the small sintered ore is classified as semi-ore and used again as a sintered raw material. At this time, as a raw iron source, small particle size ore, hematite ore, hematite, magnetite, concentrate, pellet feed, and iron-containing by-products are used. The iron source particles are hydrophilic, but the wettability of water is different depending on the surface properties, and fuel Coke and anthracite are used as hydrophobic and have very low wettability to water.

Therefore, in the normal sintering process, quicklime is used as a raw material for sintering by using quicklime as a binder in pseudo particle granulation process of mixing and bulking such raw materials and fuel.

In addition, in the production of blast furnace charge by-products such as dust, sludge, slag generated in the steelmaking process using a cement or CaO-based binder through a pelletizing or briquetting, etc. The charge may also be prepared using Cold Bonded Pellet (CBP).

It is to provide a method for producing a sintered ore excellent in breathability and excellent in combustion efficiency.

Sintered ore manufacturing method according to an embodiment of the present invention comprises the steps of assembling the addition of water to the sintered blended raw materials, including raw materials, fuel materials, semi-ores and secondary raw materials; Preparing a mixed solution by mixing a binder and water containing a cellulose ether compound; Preparing agglomerated particles by spraying the mixed solution on the assembled sintered blend raw material; And sintering the agglomerated particles; wherein the binder and the water are mixed such that the viscosity of the mixed solution is 5000 to 20000 cps.

After preparing the mixed solution, stirring the mixed solution at 1000 to 10000rpm; may be further included.

In the step of assembling, the _secondary raw material may include one or more of limestone and silica, and may adjust the basicity (CaO / SiO ₂ ) of the sintered blend raw material to 1.7 to 2.2. As such, by adjusting the basicity (CaO / SiO ₂ ), the granulation effect of the sintered blend raw material can be further improved.

In the step of preparing the mixed solution, the cellulose ether-based compound, methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl In cellulose (HEMC), 1 or more types can be included.

In the step of preparing the mixed solution, the molecular weight of the cellulose ether-based compound may be 10000 to 30000.

In the preparing of the aggregated particles, 0.1 to 3.0 wt% of the binder may be added based on 100% of the total weight of the aggregated particles.

The agglomerated particles may be 9 to 9 or more, including 58 to 63 wt% of raw materials including iron ore, 3 to 5 wt% of fuel materials, quicklime and quartz, including at least one of coke and anthracite. 13 wt% of sub-materials, 18-22 wt% of semi-gloss, 2-4 wt% of moisture, and 0.1-3 wt% of binder.

By controlling the viscosity of the cellulose ether compound and the water mixture as a binder and mixing it with the sintered blended raw material, it is possible to produce a sintered ore having excellent air permeability and excellent combustion efficiency.

1 is a diagram schematically illustrating a sintering process.
2 is a view showing a sintered ore manufacturing method according to an embodiment of the present invention.
3 is a view showing the average particle size and air permeability of the sintered ore prepared by the embodiment of the present invention and the sintered ore prepared by the comparative example.
4 is a view showing the combustion efficiency and NO _x conversion rate of the sintered ore prepared by the embodiment of the present invention and the sintered ore prepared by the comparative example.

Terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited to these. These terms are only used to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, the first portion, component, region, layer or section described below may be referred to as the second portion, component, region, layer or section without departing from the scope of the invention.

The terminology used herein is for reference only to specific embodiments and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. As used in the specification, the meaning of “comprising” embodies a particular characteristic, region, integer, step, operation, element and / or component, and the presence of another characteristic, region, integer, step, operation, element and / or component or It does not exclude the addition.

When a portion is referred to as being "on" or "on" another portion, it may be directly on or on the other portion or may be accompanied by another portion in between. In contrast, when a part is mentioned as "directly above" another part, no other part is intervened in between.

Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Commonly defined terms used are additionally interpreted to have a meaning consistent with the related technical literature and the presently disclosed contents, and are not interpreted in an ideal or very formal sense unless defined.

In addition, unless otherwise indicated,% means weight% and 1 ppm is 0.0001 weight%.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

Sintered ore  Manufacturing method

As shown in Figure 2, the sintered ore manufacturing method according to an embodiment of the present invention comprises the steps of assembling the addition of water to the sintered blended raw materials, including raw materials, fuel materials, semi-ore and secondary raw materials, comprising a cellulose ether-based compound Preparing a mixed solution by mixing a binder and moisture, spraying the mixed solution on the assembled sintered blended raw material to produce agglomerated particles, and sintering the agglomerated particles, and the viscosity of the mixed liquid in the step of preparing the mixed liquid. Mix the binder and the moisture so as to be 5000 to 20000 cps.

First, in the assembling step, a sintered blended raw material including a raw material, a fuel material, a semi-ore, and a secondary raw material is prepared.

Raw materials may include iron ore. Specifically, among iron ore, pellet feed, and iron by-products, it may include one or more. Iron ore may include hematite, brown iron and magnetite.

The fuel material may include one or more of the coke and anthracite coal. Semi-glossy is a small sintered ore which is classified as sintered semi-reflective and used again as a sintered raw material. The secondary raw material may include one or more of by-products containing limestone, silica and Ca. Specifically, among by-products containing limestone and Ca, it may include one or more, through which the basicity (CaO / SiO ₂ ) of the sintered blend raw material may be adjusted to 1.7 to 2.2.

Raw materials, fuel materials, semi-ores, and subsidiary materials prepared as described above are mixed with moisture and assembled. Specifically, of the two drum mixers constituting the sintered ore manufacturing apparatus, the first drum mixer is assembled by adding moisture to the sintered blended raw material.

Next, in the step of preparing a mixed solution is mixed with a binder containing a cellulose ether-based compound and water to prepare a mixed solution. The step of preparing the mixed liquid may be performed simultaneously with the step of assembling, and may be performed sequentially. It doesn't matter in order.

The cellulose ether-based compound included in the binder has a high viscosity in liquid form and must be diluted with water. The viscosity of the diluted mixture is adjusted to 5000 to 20000 cps.

When the viscosity of the mixed solution is less than 5000cps, the viscosity is too low, the bonding strength to the sintered blending raw material is lowered may cause a problem that the particle size of the particle is uneven or the strength is lowered. If a large amount of the mixture having a low viscosity is used to increase the strength, the moisture of the assembled sintered raw material may be excessively increased.

On the other hand, if the viscosity of the mixed solution exceeds 20000 cps, the molecular weight of the cellulose ether compound is too high, so when the liquid mixture is injected, the nozzle made of the injector of the mixed solution may be clogged or the size of the assembled sintered raw material is formed large Can cause problems.

The molecular weight of the cellulose ether-based compound included in the binder may be 10000 to 30000. If the molecular weight is less than 10000, the binding force to the sintered blend raw material may fall. On the other hand, when the molecular weight exceeds 30000, a problem of clogging the nozzle made of the injector of the mixed liquid may occur or a problem that the size of the assembled sintered blend material is formed to be huge.

Specifically, the cellulose ether compound is methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose (HEMC), 1 It may include more than one species.

Methyl cellulose (MC) has a degree of methyl group substitution of 18 to 32% by weight, and hydroxyethyl cellulose (HEC) has a degree of substitution of hydroxyethyl group of 20 to 80% by weight. Hydroxypropyl cellulose (HPC) has 20 to 80% by weight of hydroxypropyl group substitution, hydroxypropylmethylcellulose (HPMC) has 18 to 32% by weight of methyl group substitution and 2 to 14% by weight of hydroxy Propyl group substitution degree. In addition, hydroxyethyl methyl cellulose (HEMC) may have a degree of methyl group substitution of 18 to 32% by weight and a degree of substitution of hydroxyethyl group of 2 to 14% by weight.

After preparing a mixed solution by mixing a binder and water containing a cellulose ether-based compound, the method may further include stirring the mixed solution. At this time, the stirring speed of the mixed solution may be 1000 to 10000rpm.

Next, the compacted material may be prepared by spraying the mixed solution on the sintered blended raw material assembled through the preparation of the aggregated particles.

Specifically, among the two drum-type mixers constituting the sintered ore manufacturing apparatus, the agglomerated particles may be produced by spraying the mixed liquid in the second drum-type mixer.

In the mixed solution sprayed on the granulated sintered blend raw material, the binder may be added in an amount of 0.1 to 3.0% by weight based on 100% of the total weight of the aggregated particles. Specifically, 0.3 to 2.0% by weight may be added. When the amount of the binder added is too small, granulation may not be performed properly, and when too much, the proportion of the raw material may be too low.

Specifically, the agglomerated particles include at least one of 3 to 5 wt% of fuel material, limestone and quartz, including at least one of 58 to 63 wt% of raw materials including iron ore, coke and anthracite. To 13 wt% of sub-materials, 18 to 22 wt% of semi-gloss, 2 to 4 wt% of moisture, and 0.1 to 3 wt% of binder.

After the prepared liquid is sprayed on the granulated sintered blended raw material to produce agglomerated particles, the agglomerated particles may be charged into a sintering machine and sintered to complete manufacture of the sintered ore. In some cases, the molten iron may be directly supplied to the molten iron manufacturing process to produce molten iron. It can be sintered using a downward suction dwight lloyd (DL) sintering machine.

In the sintered ore manufacturing method according to an embodiment of the present invention, the quicklime and cement-based binders, which are generally used as binders, are replaced with cellulose ether-based compounds, and the viscosity of the mixed solution in which the cellulose ether-based compound and water are mixed is adjusted to 5000 to 20000 cps. The air permeability index (JPU) of the sintered ore may be 36 or more by spraying the primary assembled sintered blend material. Accordingly, an excellent combustion efficiency and low NO _x conversion rate can be expected. The average particle size may be at least 3.6 mm.

Specifically, the air permeability index (JPU) is an abbreviation of Japanese Permeability Unit and may be expressed by the following equation. The air permeability in the sinter bed can be an indicator of the air permeability. The higher the value, the better the air permeability.

[expression]

Hereinafter, specific examples of the present invention will be described. However, the following examples are only specific examples of the present invention, and the present invention is not limited to the following examples.

Example

1) Preparation of Sintered Ore

Sintered ore having a composition component according to the following table was prepared.

In the first drum-type mixer, granulated by adding water to the sintered blended raw material, in the case of the embodiment, a mixed solution was prepared by mixing a cellulose ether-based compound, specifically, a binder containing hydroxypropylmethylcellulose (HPMC) with water. The viscosity of the mixture was adjusted to 10000 cps. The viscosity value measurement of the liquid mixture was measured using Brookfield's DV-II + Pro (spindle HA) at 20 ± 0.1 degreeC.

In Comparative Example 1, a mixed solution was prepared by mixing a binder containing quicklime with water.

In Comparative Example 2 and Comparative Example 3, the components and contents of the sintered blended material were adjusted similarly to the examples. However, a mixed solution was prepared by mixing a binder containing a cellulose ether compound with water. The viscosity of the mixture was adjusted to 3000 cps and 22000 cps.

Thereafter, the sintered blended raw materials firstly assembled in the secondary drum-type mixer were mixed with the respective mixed liquids to prepare agglomerated particles, which were then sintered to prepare a sintered ore.

division Comparative Example 1 Example Comparative Example 2 Comparative Example 3 Iron Ore A (g) 567 567 567 567 Iron Ore B (g) 730 731 732 732 Iron Ore C (g) 1718 1720 1720 1720 Iron Ore D (g) 3223 3226 3225 3225 Iron Ore (g) 744 744 744 744 Iron Ore F (g) 1028 1029 1030 1029 Iron Ore G (g) 520 521 520 521 Iron Ore H (g) 1059 890 890 890 Limestone (g) 1450 1820 1822 1817 Silica (g) 29 29 29 29 Semigloss (g) 3119 3122 3120 3125 Coke (g) 301 301 301 301 Anthracite (g) 301 301 301 301 Sintered Compound Raw Material 15000 15000 15000 15000 moisture 623 340 600 290 quicklime 212 - - - bookbinder - 100 55 200 Viscosity (cps) 10000 3000 22000

In Table 1, the binder refers to a liquid binder including a cellulose ether compound.

2) Property evaluation

The air permeability index (JPU) was calculated through calculation using the above equation, and the average particle size, combustion efficiency, and NO _x conversion rate of the sintered ore were measured, respectively.

As shown in FIG. 3, the air permeability index (JPU) of the Example was 38.1, while the air permeability index (JPU) of Comparative Example 1 was 35.85, and the air permeability index (JPU) of Comparative Example 2 and Comparative Example 3 was 36.5 and 37.2, respectively. I stopped. The average particle size of the example was 3.86 mm, while the average particle size of Comparative Example 1 was 3.51 mm. Although not separately shown in FIG. 3, the average particle sizes of Comparative Example 2 and Comparative Example 3 were only 3.62 mm and 3.77 mm, respectively.

As shown in FIG. 4, the combustion efficiency of the example was 72.4%, whereas the combustion efficiency of Comparative Example 1 was only 71.2%, which was about 1.2% worse than that of the example. Although not separately shown in FIG. 4, the combustion efficiencies of Comparative Examples 2 and 3 were only 71.8% and 72.0%.

While the NO _x conversion rate of the example was 25.6%, the NO _x conversion rate of Comparative Example 1 was 28.4%, which was confirmed to be about 2.8% higher than the NO _x conversion rate. The NO _x conversions of Comparative Example 2 and Comparative Example 3 were only 27.2% and 28.1%.

The present invention is not limited to the above embodiments and / or embodiments, but may be manufactured in various forms, and a person of ordinary skill in the art to which the present invention pertains may change the technical spirit or essential features of the present invention. It will be appreciated that it can be practiced in other specific forms without doing so. Therefore, it is to be understood that the embodiments and / or embodiments described above are illustrative in all respects and not restrictive.

Claims (7)

Granulating by adding moisture to a sintered blended raw material including a raw material, a fuel material, a semi-ore, and a secondary raw material;
Preparing a mixed solution by mixing a binder and water containing a cellulose ether compound;
Preparing agglomerated particles by spraying the mixed solution on the assembled sintered blend raw material; And
Sintering the mass particles;
Sintering ore manufacturing method for mixing the binder and water so that the viscosity of the mixed solution in the step of preparing the mixed solution is 5000 to 20000cps. The method of claim 1,
After preparing the mixed solution,
Stirring the mixed solution at 1000 to 10000rpm; Sintered ore manufacturing method further comprising. The method of claim 1,
In the step of assembling,
The secondary raw material is limestone and silica, including one or more, sintered ore manufacturing method for adjusting the basicity (CaO / SiO ₂ ) of the sintered blend raw material to 1.7 to 2.2. The method of claim 1,
In the step of preparing the mixed solution,
The cellulose ether-based compound,
Sintered ore manufacturing method containing at least 1 type from methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC), and hydroxyethyl methyl cellulose (HEMC). . The method of claim 1,
In the step of preparing the mixed solution,
The molecular weight of the cellulose ether-based compound is 10000 to 30000 sintered ore manufacturing method. The method of claim 1,
In the step of preparing the mass particles,
Sintered ore manufacturing method for adding 0.1 to 3.0% by weight of the binder based on 100% by weight of the total weight of the aggregated particles. The method of claim 1,
The agglomerated particles,
58 to 63% by weight of raw materials including iron ore, 3 to 5% by weight of fuel materials including one or more from coke and anthracite, 9 to 13% by weight of submaterials including one or more among limestone and quartz , 18 to 22% by weight semi-glossy, 2 to 4% by weight of moisture and 0.1 to 3% by weight binder.

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