KR20140129502A - Production method of briquette using waste materials of ironworks - Google Patents

Abstract

The present invention relates to a method for manufacturing a briquette using a byproduct of steelmaking. The method for manufacturing a briquette using a byproduct of steelmaking includes: a step of preparing a raw material for manufacturing a briquette by mixing binder (b) in a byproduct (a) of steelmaking; a step of molding a briquette (m) by compressing and molding the raw material for manufacturing a briquette supplied between a pair of rotating rolls; and a step of curing the briquette (m). In the step of molding the briquette (m), the amount of raw material for manufacturing a briquette supplied between the rolls (23, 25) is estimated according to the rotation speed of the rolls. The method for manufacturing a briquette using a byproduct of steelmaking can increase efficiency of a briquette manufacturing work by increasing the recovery rate of a briquette.

Description

TECHNICAL FIELD [0001] The present invention relates to a briquette production method using a by-

The present invention relates to a method of manufacturing briquettes using steelmaking byproducts, and more particularly, to a method of manufacturing briquettes using steelmaking byproducts to increase the recovery rate of briquettes.

In the blast furnace process of the steel mill, the iron ore charged in the upper part of the blast furnace is melted by the hot air supplied through the tuyere to produce molten material (molten iron and slag), and the molten material accumulated in the furnace is continuously discharged through the outlet Process.

The steelmaking furnace steelmaking process is a process in which molten iron produced in the blast furnace is pretreated and then charged into a converter, oxygen gas is blown, and decarburization and thermal refining are conducted.

The electric furnace steelmaking process in steel mills is a process to produce molten steel mainly using scrap.

These steel mills produce iron-containing by-products during the blast furnace process, converter furnace process, and electric furnace steelmaking process.

Prior art relating to the present invention is Korean Patent No. 10-0797839 (Apr. 24, 2008) entitled " Briquettes and their manufacturing methods. &Quot;

The object of the present invention is to provide a briquetting method using a by-product of a steel mill, which is produced by using briquettes of a steel mill to produce briquettes, which can predict the recovery rate of briquettes according to the rotation speed of the rolls and the feed rate of the briquettes during the manufacture of briquettes, .

According to an aspect of the present invention, there is provided a method for manufacturing a briquetting material, comprising the steps of: preparing a raw material for manufacturing briquettes by mixing a binder with a by-product of a steel mill; A method of manufacturing a briquette, comprising the steps of: forming a briquette by compression molding; and curing the briquette, wherein in the step of molding the briquette, a supply amount of the briquetting raw material supplied between the pair of rolls .

The supply amount of the raw material for producing briquettes to be supplied between the pair of rolls is calculated in accordance with the rotation speed of the roll. The calculation of the raw material supply amount, the rotation speed of the roll and the briquette recovery rate, Is calculated on the basis of Equation (1).

≪ Equation &

Briquet recovery rate (%) = 100-10.1 占 (rotation speed of roll) + 0.862 占 (raw material feed rate)

In the above Equation

The briquette recovery rate is a regression analysis method showing the correlation between the rotation speed of the roll and the feed rate of the raw material which can obtain 85% or more of briquettes having a particle diameter of 20 mm or more.

The binder includes cement and molasses.

The steelmaking by-product includes at least one of blast furnace dust, calcined sludge, steelmaking sludge, steelmaking dust, and mill scale.

The present invention can predict the recovery rate of the coke depending on the feed rate of the raw material supplied to the breaker and the rotation speed of the roll.

Therefore, it is possible to increase the recovery rate of the briquettes and to increase the efficiency of the briquette production operation by calculating the supply amount of the raw material for producing briquettes to be supplied between the pair of rolls at the time of briquetting, according to the rotation speed of the rolls.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for explaining a briquetting method using a steelmaking by-product according to the present invention. FIG.
2 is a graph showing a change in the recovery rate of the briquette according to the rotation speed of the roll and the feed rate of the raw material.
FIG. 3 is a graph showing a correlation between a predicted value of the recovery rate applied to the briquetting method using the steelmaking by-product according to the present invention and a measured value measured after manufacturing the briquettes.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The method for manufacturing briquettes using the steelmaking by-products of the present invention secures the efficiency of manufacturing briquettes by securing the recovery rate of briquettes through the supply of raw materials for manufacturing appropriate briquettes during manufacturing of briquettes.

During the blast furnace process and steelmaking process, steel mill by-products containing iron are generated at steel mills. The steelmaking by-products include at least one of blast furnace dust, calcined sludge, steelmaking sludge, steelmaking dust, and mill scale.

Dust can occur during the transport of coal, and sludge can occur during the process of collecting flue-gases during the manufacture of molten iron or molten steel.

By-products from steel mills occur thousands of tons a day and are too small to be stored in the storage, which is likely to be lost by wind. By-products from steel mills cause additional environmental pollution if they are lost, and are difficult to transfer even when used in other steelmaking processes, so they are not suitable for use without processing.

Therefore, it is used in the industrial field after making the briquettes solidified in the form of various lumps in the form of powdery iron byproducts which can not be economically used.

The by-product of the steel mill is manufactured as a briquette using a briquetting machine (briquetter).

In addition, steel mills' by-products contain a large amount of iron, and thus become main raw materials in the manufacture of briquettes. As described above, the following method is applied so that the recovery rate of the briquettes can be increased when manufacturing the briquettes by using the steelmaking by-products as the main raw material.

Specifically, the method comprises the steps of: preparing a raw material for manufacturing briquettes by mixing a binder (b) with a steel byproduct (a); feeding the raw material for producing briquettes between a pair of rotating rolls (23, 25) and a step of curing the briquettes (m). In the step of molding the briquettes (m), the supply amount of the briquetting raw material supplied between the pair of rolls (23, 25) (23, 25).

The raw materials can be mixed in the range of 93 ~ 98% of the by-product of the steel mill and 2 ~ 7% of the binder.

The steelmaking byproduct (a) includes at least one of blast furnace dust, calcined sludge, steelmaking sludge, steelmaking dust, and mill scale.

The binder (b) is for solidifying the steel mill by-product (a) and ensuring strength.

The binder (b) contains cement and molasses. Cement is intended to develop long-term strength of the briquet, and molasses is to express the initial strength of the briquet.

Cement can be made of ordinary cement.

Molasses is a by-product of making sugar from sugarcane. Molasses is very viscous and should be mixed with water according to the working conditions. The molasses and water are preferably mixed in a ratio of 6: 4.

Molasses may be included in a warmed state to improve mixing efficiency. Preferably at a temperature of 40 to 55 < 0 > C.

As shown in Fig. 1, the steel mill by-product a and the binder b are mixed in the raw material mixer 11. The raw mixer 11 is provided with a spiral screw 13 and mixes the steelmaking byproduct a supplied by rotation with the binder b. The screw 13 may be rotated by an external driving source, for example, to the driving motor 15 or the like.

The retention time of the raw material in the raw material mixer 11 can be adjusted according to the mixing efficiency. For example, it can be adjusted between 1 and 7 minutes. If the residence time of the raw material in the raw material mixer 11 is less than the above-mentioned range, the mixing becomes insufficient and causes a decrease in the brittle strength. If the above range is exceeded, the operating time is increased by the increase of the residence time, Can be reduced.

The water content of the raw materials mixed in the raw mixer (11) can be adjusted by controlling the water content of the molasses, controlling the drying condition of the steelmaking by-products, and adjusting the content ratio of the sludge and the dust.

The raw material mixed in the raw mixer (11) is supplied to the breather (21) through the storage hopper (17).

The upper portion of the storage hopper 17 is opened and an outlet 19 for discharging the raw material is formed in a space for filling the raw material therein. This outlet (19) is connected to the breather (21).

The applicator (21) has a pair of rolls (23, 25) rotating in opposite directions. The raw material is charged between a pair of rolls (23, 25) and compression molded to produce briquettes (m). Any one roll 23 of the pair of rolls 23 and 25 can move in a direction close to the remaining rolls 25 to adjust the distance between the rolls 23 and 25. The movement of any one of the pair of rolls 23 and 25 in the direction in which the other rolls 25 are brought into close contact with the other rolls 25 causes the rotation of the rolls 23, (27a).

The rotation speed of the rolls 23 and 25 is controlled by the control unit 29. [ The rolls 23 and 25 are provided with rotation shafts 23a and 25a at the center of the rolls 23 and 25 and reduction gears (not shown) and motors (not shown) connected to the rotary shafts 23a and 25a, The control unit 29 controls the rotation speed of the rolls 23 and 25.

The shape of the briquettes (m) can be variously processed such as cylindrical or circular depending on the shape of the user or the raw material. The briquettes (m) have no limitation on the upper limit of the diameter, and can be suitably designed in accordance with the kind and shape of the steelmaking by-products in the range of the lower limit of 20 mm or more.

If the diameter of the molded briquettes m is less than 20 mm, the strength of the briquettes m is liable to be weak and fragile. If the briquettes m are easily broken, the briquettes m have no meaning, Environmental pollution can be caused.

The supply amount of the raw material for producing briquettes to be supplied between the pair of rolls 23 and 25 is adjusted in accordance with the rotation speed of the rolls 23 and 25 in the step of molding the briquettes m so as to increase the recovery rate of the briquettes m .

The raw material supply amount and the rotation speed of the roll are calculated based on the following formula.

≪ Equation &

Briquet recovery rate (%) = 100-10.1 占 (rotation speed of roll) + 0.862 占 (raw material feed rate)

(R ² = 0.79)

In Equation (1), the briquette recovery rate is obtained by regression analysis of the relationship between the rotation speed of the roll and the feed rate of the roll, which can obtain 85% or more of briquettes having a diameter of 20 mm or more.

The correlation coefficient between the briquette recovery rate and the actual briquette recovery rate derived from regression analysis is 0.79, which is close to 1. The closer the correlation coefficient is to 1, the higher the correlation.

A regression analysis method is a statistical technique that explains and predicts the value of a particular variable from one or more other variables (independent variables) by determining the relationship between two or more variables.

The briquette diameter of 20 mm or more is to secure the strength of the briquette. If the diameter of the briquette is less than 20 mm, the strength is weak and it is easily broken.

The higher the target recovery rate is, the better, but the higher the target recovery rate,

Proper densities and appropriate pressurization times are required for briquettes (m) to be well formed.

The rotation speed of the rolls 23 and 25 is fast and the amount of the raw material supplied between the rolls 23 and 25 is small when the amount of raw materials is small so that the density of one briquette m is small, 25), so that the product is easily broken and a product having a target value (diameter of 20 mm) or more is made small. As a result, the molding rate of the briquettes m is lowered and the recovery rate of the briquettes m is reduced.

As such, the recovery rate of the briquet is dependent on the feed rate of the feedstock fed between the two rolls 23,25 forming a pocket that exactly matches each other and the rotational speed of the two rolls 23,25.

Therefore, based on the above equations, a quantitative raw material supply amount corresponding to the rotational speed of the rolls 23 and 25 of the breather 21 is calculated, and the recovery rate of the briquettes m is secured through proper raw material supply The efficiency of the operation can be increased.

The shape of the briquettes (m) can be varied and used depending on the shape of the user or the raw material. There is no restriction on the upper limit value, and as described above, it is possible to suitably design according to the kind and form of the by-product of the steel mill in a range of 20 mm or more.

The molded briquettes (m) are sorted through a screen-type particle size selector (31), and the selected briquettes (m) undergo a curing process for strength development. Curing can be carried out by drying at room temperature for about one day.

After curing, the briquettes preferably have a moisture content of more than 0 and 5% or less. If the water content of the briquettes (m) exceeds 5%, there is a possibility of explosion when put into the high-temperature converter, and 0% is not possible due to the current operating conditions.

The brittle material (powder) having a particle size of less than 20 mm may be mixed with the raw material mixed in the raw material mixer 11 after the mixture is introduced into the raw material mixer 11.

The briquettes (m) produced by the above-mentioned method consist of steelmakers by-products and binders, and the recovery rate (diameter 20 mm or more) is 85% or more. The steelmaking by-product includes at least one of blast furnace dust, calcined sludge, steel sludge, steel dust, mill scale, and the binder includes cement and molasses.

Hereinafter, the present invention will be described in more detail with reference to experimental examples. However, the following experimental examples are provided for illustrating the present invention, and the present invention is not limited thereto, and various modifications and changes may be made.

<Experimental Example>

The condition that the quality of the briquette can be ensured by varying the supply amount of the raw material according to the rotation speed of the rollers of the breaker was experimented.

The recovery rate of briquettes was investigated by varying the rotational speed of the rolls from 1.5 to 6 rpm in four steps and varying the feed rate from 120 to 600 g / sec in five steps. The recovery rate of briquettes is expressed as (briquette particle size of 20 mm or more / total raw material supply) x 100.

2 is a graph showing changes in the recovery rate of briquettes according to the rotation speed of the roll and the feed amount of the raw material.

In FIG. 2, a section in which the recovery rate of briquettes of 85% or more is obtained from the raw material feed rate according to the rotation speed of the roll is indicated by a hatched area.

As shown in FIG. 2, it can be seen that the recovery rate of the briquette changes depending on the rotation speed of the roll and the feed amount of the raw material.

As a result, it can be seen that the recovery rate of the briquet can be increased to 85% or more by estimating the feed amount of the raw material according to the rotation speed of the roll.

FIG. 3 is a graph showing a correlation between a predicted value of the recovery rate applied to the briquetting method using the steelmaking by-product according to the present invention and a measured value measured after manufacturing the briquettes.

3, it is confirmed that the recovery rate predicted value derived by the equation for calculating the supply amount of the raw material for manufacturing briquetting according to the rotation speed of the roll has a correlation with the measured value.

Through the experimental results,

&Lt; Equation &

It is possible to increase the recovery rate of the briquettes by preparing the briquettes based on the rotation speed of the rolls using the briquette recovery rate (%) = 100-10.1 x (rotation speed of the roll) + 0.862 x Able to know.

It is to be understood that the invention is not limited to the disclosed embodiments, but is capable of many modifications and alterations, all of which are within the scope of the appended claims. It is self-evident.

11: raw material mixer 13: screw
15: drive motor 17: storage hopper
19: Exit 21: Breketer
23, 25 rolls 23a, 25a:
27: cylinder 27a: rod
29: control unit 31: particle size selector
m: Briquettes a: Steelmaking by-products
b: Binder

Claims (5)

Preparing a raw material for manufacturing briquettes by mixing a binder with a by-product of a steel mill;
Feeding the raw material for manufacturing briquettes between a pair of rotating rolls and compressing the raw material to mold the briquettes;
Curing the briquettes,
Wherein the feed rate of the raw material for producing briquettes fed between the pair of rolls is calculated in accordance with the rotation speed of the roll in the step of molding the briquettes. The method according to claim 1,
The supply amount of the raw material for producing briquettes to be supplied between the pair of rolls is calculated according to the rotation speed of the roll,
And the briquette recovery rate is calculated based on a relationship between the raw material supply amount, the rotation speed of the roll, and the briquette recovery rate.
&Lt; Equation &
Briquet recovery rate (%) = 100-10.1 占 (rotation speed of roll) + 0.862 占 (raw material feed rate) The method of claim 2,
In the above Equation
Wherein the briquette recovery rate is a regression analysis method showing a correlation between the rotation speed of the roll and the feed rate of the raw material that can obtain 85% or more of briquettes having a grain size of 20 mm or more. The method according to claim 1,
Wherein the binder comprises cement and molasses. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt; The method according to claim 1,
Wherein the by-product of the steel mill includes at least one of blast furnace dust, calcined sludge, steel sludge, steel dust, and mill scale.

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