KR20190061775A - Manufacturing method of sintered ore - Google Patents

Abstract

Adding moisture to the sintering raw material containing the raw material, the fuel material, and the additive material, and assembling the same; Mixing a binder containing a cellulose ether compound and water to prepare a mixed solution; Spraying the mixed solution onto the sintered blended raw material to produce bulk particles; And a step of sintering the agglomerated particles. In the step of preparing the mixed solution, a method of producing the sintered ores by mixing the binder and the water so that the viscosity of the mixed solution becomes 5000 to 20000 cps is introduced.

Description

Technical Field [0001] The present invention relates to a method of manufacturing a sintered ore,

The present invention relates to a method for producing an sintered ores having excellent air permeability and excellent combustion efficiency.

Generally, the sintering process is a process for producing sintered ores by processing iron ore to facilitate use in a furnace. Sintered ores can be produced by mixing iron ore with coke, fuel, limestone, and additives, followed by sintering.

The sintered ores may be produced in the following order. First, raw materials mixed with iron ore, fuel, coke, and additives are charged at a constant height to the bogie. Then, when air is forcedly sucked from the lower side after ignition of the upper part of the raw material, sintering of the raw material proceeds to produce sintered ores.

Thereafter, the sintered ores having an easy particle size in the blast furnace and the reaction are transferred to the blast furnace, and the sintered ores having a small size are classified as semi-light and used again as raw materials for sintering. In this case, iron sources such as hematite (hematite, maltite, and magnetite), concentrate, pellet feed, and iron-iron by-products are used as the raw iron source. Iron source particles are hydrophilic but have different wettability to water depending on their surface characteristics. Coke and anthracite are hydrophobic and have very low wettability to water.

Therefore, in the ordinary sintering process, the raw lime is used as a binder in the pseudo particle assembling process in which the raw material and the fuel are mixed and agglomerated, and they are used as raw materials for sintering after the agglomeration process.

In addition, byproducts such as dust, sludge, and slag generated in a steel making process can be massed through pelletizing or briquetting using a cement or CaO binder in the manufacture of blast furnace charge, We also use cold bonded pellets (CBP) to make charges.

A method for producing an sintered ore having excellent air permeability and excellent combustion efficiency will be provided.

According to an embodiment of the present invention, there is provided a method of manufacturing sintered ores by adding moisture to a sintering / blending raw material including a raw material, a fuel material, a semi-light and an additive material, Mixing a binder containing a cellulose ether compound and water to prepare a mixed solution; Spraying the mixed solution onto the sintered blended raw material to produce bulk particles; And sintering the agglomerated particles. In the step of preparing the mixed solution, the binder and the water are mixed so that the viscosity of the mixed solution becomes 5000 to 20000 cps.

And stirring the mixed solution at 1000 to 10,000 rpm after the step of preparing the mixed solution.

In the granulating step, the additive material may include at least one of limestone and silica, and the basicity (CaO / SiO ₂ ) of the sintering raw material may be adjusted to 1.7 to 2.2. By adjusting the basicity (CaO / SiO ₂ ), the effect of assembling the sintering raw material can be further improved.

In the preparation of the mixed solution, the cellulose ether compound may be selected from the group consisting of methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropylmethyl cellulose (HPMC) and hydroxyethyl methyl And cellulose (HEMC).

In the step of preparing the mixed solution, the molecular weight of the cellulose ether compound may be 10,000 to 30,000.

In the step of producing the agglomerated particles, 0.1 to 3.0% by weight of the binder may be added based on 100% of the total weight of the agglomerated particles.

Wherein the agglomerated particles comprise 58 to 63% by weight of raw material including iron ore, 3 to 5% by weight of fuel material containing at least one of coke and anthracite, 9 to 20% 13 wt% of an additive material, 18 to 22 wt% of a semi-light, 2 to 4 wt% of water, and 0.1 to 3 wt% of a binder.

It is possible to produce an sintered ores having excellent air permeability and excellent combustion efficiency by controlling the viscosity of the cellulose ether compound and the water mixture as the binder and mixing them with the sintering blend material.

Figure 1 is a diagrammatic representation of the sintering process.
2 is a view illustrating a method of manufacturing sintered ores according to an embodiment of the present invention.
FIG. 3 is a graph showing the average particle size and air permeability of the sintered ores produced according to an embodiment of the present invention and the sintered ores produced according to the comparative example.
4 is a graph showing the combustion efficiency and the NO _x conversion of the sintered ores produced according to an embodiment of the present invention and the sintered ores produced by the comparative example.

The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

When referring to a portion as being "on" or "on" another portion, it may be directly on or over another portion, or may involve another portion therebetween. In contrast, when referring to a part being "directly above" another part, no other part is interposed therebetween.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Unless otherwise stated,% means% by weight, and 1 ppm is 0.0001% by weight.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Sintered ore  Manufacturing method

As shown in FIG. 2, the method for producing sintered ores according to an embodiment of the present invention includes the steps of adding moisture to a sintering blend material containing a raw material, a fuel material, a semi-light and an additive raw material, A step of mixing a binder and water to prepare a mixed solution, a step of spraying a mixed solution to the assembled sintering blend raw material to produce bulk particles, and a step of sintering the bulked particles. In the step of producing the mixed solution, Is mixed with the binder and the water so as to have a viscosity of 5,000 to 20,000 cps.

First, in the assembling step, a raw material for sintering, a fuel material, and a sintering raw material containing a semi-light and an additive material are prepared.

The raw material may include iron ores. Specifically, it may include at least one of min iron ore, pellet feed, and iron by-product. Minute iron ores may include hematite, galena and magnetite.

The fuel material may include at least one of coke and anthracite. Reflected light is a small-sized sintered ore, which is classified as sintered semi-transparent and used again as a raw material for sintering. The additive material may include at least one of the by-products containing limestone, silica and Ca. Specifically, one or more kinds of byproducts containing limestone and Ca may be contained, and the basicity (CaO / SiO ₂ ) of the sintering raw material may be adjusted to 1.7 to 2.2.

The raw material, the fuel material, the semi-light and the additive material thus prepared are mixed together with moisture and assembled. Specifically, of the two drum type mixers constituting the sintered-light producing apparatus, water is added to the sintering-blending raw material in the first drum type mixer and assembled.

Next, in the step of producing a mixed solution, a mixed solution is prepared by mixing a binder containing a cellulose ether compound and water. The step of preparing the mixed solution may be carried out simultaneously with the step of assembling, and may be carried out sequentially. It is not in any order.

Since the cellulose ether compound contained in the binder is a liquid type and has a high viscosity, it should be diluted with water. The viscosity of the diluted mixed solution is adjusted to 5,000 to 20,000 cps.

When the viscosity of the mixed solution is less than 5000 cps, the viscosity is too low, so that the bonding force to the sintering raw material is lowered, so that the particle size of the particles may be uneven or the strength may be lowered. If a mixed solution having a low viscosity is used in a large amount to increase the strength, moisture of the sintered blended raw material may be excessively increased.

On the other hand, when the viscosity of the mixed solution exceeds 20,000 cps, the molecular weight of the cellulose ether compound is too high, so that when the mixed solution is sprayed, the nozzle made of the injector of the mixed solution becomes clogged or the size of the assembled sintered blend material becomes large There may be a problem.

The molecular weight of the cellulose ether compound contained in the binder may be 10,000 to 30,000. If the molecular weight is less than 10,000, the bonding strength to the sintering raw material may be deteriorated. On the other hand, when the molecular weight is more than 30,000, there is a problem that the nozzles formed by the injector of the mixed solution are clogged or the size of the sintered blended raw material is large.

Specifically, the cellulose ether compound is selected from the group consisting of methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropylmethyl cellulose (HPMC) and hydroxyethyl methyl cellulose Or more species.

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

The step of mixing the binder and the water-containing cellulose ether compound to prepare a mixed solution may further include stirring the mixed solution. At this time, the stirring speed of the mixed solution may be 1000 to 10000 rpm.

Next, the compacted material can be manufactured by injecting the mixed solution to the assembled sintered mixture material through the step of producing the agglomerated particles.

Concretely, among the two drum type mixers constituting the sintered-light producing apparatus, the mixed liquid is injected in the second drum type mixer, whereby the agglomerated particles can be produced.

In the mixed liquid sprayed onto the assembled sintered blend 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 agglomerated particles. Specifically, 0.3 to 2.0% by weight may be added. If the amount of the binder is too small, the assembly may not be performed properly, and if the amount of the binder is too large, the proportion of the raw material may be too low.

Specifically, the agglomerated particles include 58 to 63% by weight of raw material including iron ore, 3 to 5% by weight of fuel material containing at least one of coke and anthracite, 9 To 13% by weight of an additive material, 18 to 22% by weight of a collimator, 2 to 4% by weight of water and 0.1 to 3% by weight of a binder.

After the agglomerated particles are produced by spraying the mixed liquid on the assembled sintered blend material, the agglomerated particles are charged into the sintering machine and sintered to complete the manufacture of the sintered ores. In some cases, the agglomerated particles can be directly supplied to the molten iron manufacturing process to produce molten iron. It can be sintered using a dwight lloyd (DL) sintering machine.

In the method for producing sintered ores according to an embodiment of the present invention, the quicklime and the cement based binder used as a binder are replaced with a cellulose ether compound, and the viscosity of a mixture of a cellulose ether compound and water is adjusted to 5,000 to 20,000 cps (JPU) of the sintered ores may be 36 or more when they are injected into the primary sintered blend material. As a result, the combustion efficiency is excellent and the effect of reducing the NO _x conversion 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 can be expressed by the following expression. Can be an index indicating the air permeability in the sintering machine bed, and the higher the numerical value, the better the air permeability.

[expression]

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

Example

1) Manufacture of sintered ores

The sintered ores having compositional components according to the following table were prepared.

In the case of the embodiment, a binder containing cellulose ether compound, specifically, hydroxypropyl methylcellulose (HPMC) is mixed with water to prepare a mixed solution. , And the viscosity of the mixed solution was adjusted to 10,000 cps. The viscosity of the mixed solution was measured at 20 ± 0.1 ° C using Brookfield's DV-II + Pro (spindle HA).

In the case of Comparative Example 1, a binder containing burnt lime was mixed with water to prepare a mixed solution.

In the case of Comparative Example 2 and Comparative Example 3, the components and the contents of the sintering raw materials were controlled similarly to the examples. However, the binder containing the cellulose ether compound was mixed with water to prepare a mixed solution. The viscosity of the mixture was adjusted to 3000 cps and 22000 cps.

Then, the sintered blend materials were mixed with each mixed solution to prepare agglomerated particles, which were sintered to produce sintered ores.

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 E (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 Reflected light (g) 3119 3122 3120 3125 Coke (g) 301 301 301 301 Anthracite (g) 301 301 301 301 Sintering Ingredients 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 means a liquid binder containing a cellulose ether compound.

2) Evaluation of physical properties

The air permeability index (JPU) was calculated by using the above formula, and the average particle size of the sintered ores, the combustion efficiency and the NO _x conversion were measured.

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

As shown in FIG. 4, the combustion efficiency of the embodiment was 72.4%, while the combustion efficiency of Comparative Example 1 was 71.2%, which was about 1.2% lower 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%, respectively.

Embodiment NO _x conversion rate is NO _x conversion rate of 25.6%, whereas the comparative example 1 was confirmed to be 28.4% or higher to around 2.8% NO _x conversion rate than the embodiment. The NO _x conversion ratios of Comparative Example 2 and Comparative Example 3 were only 27.2% and 28.1%, respectively.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. It will be understood that the invention may be embodied in other specific forms without departing from the spirit or scope of the invention. It is therefore to be understood that the embodiments and / or the examples described above are illustrative in all aspects and not restrictive.

Claims (7)

Adding moisture to a sintering raw material containing a raw material, a fuel material, a semi-light and an additive material, and assembling the raw material;
Mixing a binder containing a cellulose ether compound and water to prepare a mixed solution;
Spraying the mixed solution onto the sintered blended raw material to produce bulk particles; And
And sintering the agglomerated particles,
Wherein the binder and the water are mixed so that the viscosity of the mixed solution becomes 5,000 to 20,000 cps in the step of preparing the mixed solution. The method according to claim 1,
After the step of preparing the mixed solution,
And stirring the mixture at 1000 to 10000 rpm. The method according to claim 1,
In the assembling step,
The additives material is sintered ore production method in which limestone and silica, comprising at least one member, to adjust the basicity (CaO / SiO ₂₎ in the sintering raw material by blending from 1.7 to 2.2. The method according to claim 1,
In the step of preparing the mixed solution,
The above-mentioned cellulose ether-
A method for producing a sintered ore containing at least one of methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropylmethyl cellulose (HPMC) and hydroxyethyl methyl cellulose (HEMC) . The method according to claim 1,
In the step of preparing the mixed solution,
Wherein the molecular weight of the cellulose ether compound is 10000 to 30000. The method according to claim 1,
In the step of producing the agglomerated particles,
Wherein the binder is added in an amount of 0.1 to 3.0 wt% based on 100 wt% of the total weight of the agglomerated particles. The method according to claim 1,
The above-
58 to 63% by weight of raw materials including iron ores, 3 to 5% by weight of fuel materials comprising at least one of coke and anthracite, 9 to 13% by weight of an additive material comprising at least one of limestone and silicate By weight, 18 to 22% by weight of light, 2 to 4% by weight of water and 0.1 to 3% by weight of a binder.

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