KR20130034492A - Method of manufactureing briquette using scale - Google Patents

Abstract

PURPOSE: A method for manufacturing briquettes using scale is provided to prevent the annealing, sticking, and other phenomena of briquettes while the briquettes move from a storage to ironworks and to prevent environmental accidents. CONSTITUTION: A method for manufacturing briquettes using scale comprises: a step for collecting and drying scale generated in a rolling process, a continuous casting process, or a forging process(S100); a step for mixing the dried scale and a binder composed of alumina cement, water glass, and silicic acid to form a mixture(S120); a step for compressing the mixture to make briquettes(S130); a step for classifying the briquettes according to particle sizes(S140); and a step for remixing small briquettes with the binder. [Reference numerals] (AA) No; (BB) Yes; (S100) Drying rolling scale; (S110) Mixing a binder; (S120) Compression molding the mixture; (S130) Briquette diameter >= 6mm ?; (S140) Storing and shipping;

Description

Manufacturing method of briquette using scale {METHOD OF MANUFACTUREING BRIQUETTE USING SCALE}

The present invention relates to a method for producing briquettes, and more particularly, to a method for producing briquettes using a binder containing alumina cement in mill scale, which is a cold roll material scale.

In general, water-containing scales are generated in the process of removing the oxide scale formed in slabs or coils in water treatment facilities of steelmaking and rolling processes. The powder mill scale generated in the steelmaking process such as the forging process has a main component of FeO and Fe ₂ O ₃ and has a specific gravity of 3.65.

When such a mill scale is specially processed, the processing cost is high, and a method of manufacturing the briquette and recycling it as a raw material has been devised.

In the method of manufacturing steel raw materials using steel by-products, dry calcined sludge alone is dried and pelletized to be recycled as steel raw materials, or carbonaceous materials are added to dust, rolling scale, and pellets are prepared using starch as a binder. There is a method for reuse in the steelmaking process. However, when only starch is used as a binder, the strength of the molded body is weak, which may cause crushing or dust generation when reused in a steel mill or when transporting it by truck.

In addition, millscale furnaces of a certain size or less are difficult to recycle as raw materials in the blast furnace process, and in order to use them, compression molding in the form of briquettes is preferable. In the past, bentonite was used as a binder. .

This is to use bentonite mixed with water, which is described in Korean Patent Laid-Open Publication No. 2005-0063921, by using bentonite (the main component of SiO ₂ , CaO, MgO) as a binder, Ca in the intermetallic space And Mg is swollen by water to fill the space, the water is evaporated later takes a long time to evaporate, because the binding strength between the materials is weak, there is a problem that brittle brittleness is weak when handling.

In addition, in order to transfer the mill scale to the outside in the steel mill, dust generation is latent, and in order to prevent environmental accidents during the transfer process, less than 5% of moisture must be added to the mill scale to prevent scattering dust, and processed into scale briquettes. Even after bringing it into the company, it is sent directly to the blast furnace after moving from the outside storage to the steel mill, which may cause loosening and seizure due to rain, or environmental accidents due to product breakdown and differentiation.

In addition, some by-products that cannot be directly recycled are solidified and buried in the sea, but can cause environmental problems such as secondary marine pollution.

Embodiments of the present invention to provide a method for improving the strength of briquettes by adding a binder containing alumina cement when manufacturing mill scale to briquettes.

One or more embodiments of the present invention includes the steps of collecting and drying the scale generated in the rolling process, the playing process or the forging process; Mixing a binder comprising a mixture of the dried scale with alumina cement, water glass, and silicic acid to form a mixture; Compressing the formed mixture to process briquettes; Particle size sorting of the processed briquettes; And remixing briquettes smaller than the size set in the particle size selection step with the binder. The briquette manufacturing method using a scale may be provided.

In one or more embodiments of the present invention, the binder is characterized in that 4 to 10% by weight.

In one or more embodiments of the present invention, the size set in the particle size selection step is characterized in that the diameter of briquettes is 6.0 mm.

Embodiments of the present invention can improve the strength of the briquettes manufactured by using the mill scale, and the mill scale can be recycled by producing the briquettes using the discarded mill scale, thereby reducing the cost.

In addition, during the transfer of briquettes can prevent phenomena such as loosening, seizure due to the rain during the movement from the reservoir to the steel mill, and can prevent environmental accidents due to cracking, differentiation, etc. of the product.

1 is a flowchart of a method of manufacturing briquettes according to an embodiment of the present invention.
2 is a graph showing the effect of aging according to the use of MSP according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention, and are not intended to limit the scope of the inventions. I will do it.

Hereinafter, a method of manufacturing briquettes according to an embodiment of the present invention will be described with reference to FIG. 1.

The mill scale, which is iron oxide produced in the rolling process, especially in the hot rolling process, the reworking process, and the forging process, is collected in the steel manufacturing process, and the mill scale is dried in a drier (S100). It is a process to reduce water content in advance. The process of drying the scale may be by a method of passing the dryer through a common method.

The binder is mixed to the dried scale in a mixer (S110). At this time, the binder is to enhance the bonding strength of the scale, and to add alumina cement, which is an adhesive material for forming dust, or to the briquettes. Water glass and silicic acid are additionally added to enhance strength, and the water glass also serves to lower the melting point of the spectroscopy.

The alumina cement is used for the purpose of curing in a short time with cement having alumina content higher than that of portland cement. After mixing and melting or calcining alumina oxide and a calcium-based material, the obtained clinker is pulverized into a powder to form an adhesive force. Height functions. Alumina cement is particularly used to control the properties of mortar such as fluidity, hardening, strength development, and the like.

The amount of the binder is 4 to 10% by weight, if less than 4% by weight is insufficient to improve the compressive strength, if the content exceeds 10% by weight of the liquid mixture of the raw material is excessive in the production of briquettes in briquette manufacturing Not only are there problems with demoulding, but they are not economical.

Thereafter, the mixture of the mill scale and the binder is compressed and processed into briquettes (S120). The briquettes are introduced into a briquetting maker and manufactured into briquettes using a conventional method. At this time, the mixture is compression molded to produce briquettes. The briquettes can be processed by a briquette maker used in twin roll or press briquette production.

The manufactured briquettes are returned to the step S110 again when the particle size is smaller than the set size through the particle size selection process (S130) and remixed with the binder. The criterion for particle size selection according to an embodiment of the present invention is 6.0 mm. That is, if the diameter of the manufactured briquette is 6.0mm or more, it is regarded as normal and shipped after temporary storage (S140), but briquettes having a diameter of less than 6.0mm are remixed with the binder because they fall short of the standard.

If the particle diameter of briquettes is 6.0 mm or less, not only high intensity is expressed but also the amount of fine powders is increased. Therefore, in the embodiment of the present invention, when the diameter of briquettes is less than 6.0 mm, the mixture is put into a mixer and remixed until the briquettes have a diameter of 6.0 mm or more.

This is because the molding is not good when the particle size of the raw material used in the manufacture of briquettes is thick, and since the molding strength is reduced, the particles are recycled to produce briquettes when the particles are small.

The briquettes prepared by the above method had 78.4% of TI (Tumbling Index) strength, which was improved from 75.5% of the case of using bentonite, sugar, and water glass as binders, and the compressive strength was 120kgf / cm ² to 322kgf / cm ² . Improved. At this time, the TI value is a value representing the fraction of the sieve by passing through a screen having a constant size after putting the briquette in the cylindrical container and rotated.

Figure 2 is a graph showing the results of testing the impact of aging according to the use of Mill Scale Pellet (MSP) according to an embodiment of the present invention. This was done over 40 hours with a total of 820 tonnes tested at 0.5 tonnes per charge, then increasing 1.0 to 2.0 tonnes per charge.

In FIG. 2, BV means air volume, H / L means heat loss, BP means wind pressure, k means furnace pressure, and CBP means non-fired pellets.

Operation was minimized during the test period to determine the impact of MSP briquettes, and the pre-test CBP usage was reduced from 2.5 tons to 1 ton per charge.

According to an embodiment of the present invention, when the MSP emission characteristics are cut out at the gate, the generation amount of the dust is about 10-20%, but 100% is filtered out, and only the MSP in the ingot state is granulated, and 5 hours after the initial use of 0.5 tons Until the heat loss (H / L) has risen to about 2500, but it can be seen that it is stable.

In addition, when 1.0 ton of MSP briquettes are charged, the air volume BV may be temporarily reduced, which is not directly related to the test according to the embodiment of the present invention, since the wind speed is reduced.

Conventionally, when the scale briquettes are used in the blast furnace, more than 60% has already been differentiated from the blast furnace (bin) before charging in the furnace, and thus it was not possible to use them due to deterioration of breathability. The abnormal state was maintained in a non-differentiated state, and conventionally, moisture was added to prevent scattering dust even when manufacturing mill scales, but the briquettes according to the embodiment of the present invention did not need to add water separately.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And all changes to the scope that are deemed to be valid.

Claims (3)

Collecting and drying the scale generated in the rolling process, the playing process or the forging process;
Mixing a binder comprising a mixture of the dried scale with alumina cement, water glass, and silicic acid to form a mixture;
Compressing the formed mixture to process briquettes;
Particle size sorting of the processed briquettes; And
Remixing briquettes smaller than the size set in the particle size selection step with a binder;
Briquette manufacturing method using a scale comprising a. The method of claim 1,
The binder is briquette manufacturing method using a scale, characterized in that 4 to 10% by weight. The method of claim 1,
The size set in the particle size selection step is a briquette manufacturing method using a scale, characterized in that the diameter of briquettes 6.0mm.

Images