KR20120038663A - Briquette for increasing temperature of the molten metal using low quality silicon carbide and method of fabricating the same - Google Patents

Abstract

PURPOSE: Briquet for increasing the temperature of molten metal using low quality silicon carbide, and a producing method thereof are provided to prevent the generation of dust, and to decrease the temperature increasing time of the molten metal. CONSTITUTION: A producing method of briquette(132) for increasing the temperature of molten metal comprises the following steps: mixing 90-98wt% of low quality silicon carbide containing 50-80wt% of waste silicon with 2-10wt% of binder; and compressing the mixture(130) into the first diameter. The briquette contains 45-78.4wt% of silicon, 17.55-48.02wt% of carbon, 2-10wt% of binder, and 0.45-0.98wt %of impurities.

Description

Briquette for increasing temperature of the molten metal using low quality silicon carbide and method of fabricating the same}

The present invention relates to a briquette used for heating the molten metal in the steelmaking process and activating the melting of the steelmaking product. More specifically, a briquette for heating a molten metal, characterized in that it is produced by recycling low-grade silicon carbide. And to a method for producing the same.

As a heating element for raising the temperature used in the steelmaking industry, a ferro-silicon (Fe-Si) ingot having an Si content of 75% by weight to 80% by weight, anthracite coal, or coke ingot is mainly used. The ferrosilicon has a melting point of about 1,350 ° C., which is lower than the temperature of the molten metal but relatively high, and its specific gravity is also lower than that of the molten metal.

Therefore, when the ferrosilicon ingot is introduced into the molten metal, the dissolution rate is slow and the oxidation reaction rate is delayed.

In addition, when the anthracite mass has a high melting point, when it is added into the molten state in a molten state, the oxidation reaction rate is slow, and the specific gravity is very low, so it floats on the molten metal. Doing.

In order to improve this problem, in order to increase the dissolution rate of ferrosilicon or carbon ingot which is introduced into the molten metal for heating, the size of ferrosilicon, anthracite coal, coke, etc. is added to the molten metal in the form of particles having a particle size of 10 mm or less. The dissolution rate is increased to reduce the temperature rise time of the molten metal.

However, this method causes a lot of dust in the manufacturing and conveying process due to the small particles of raw materials introduced into the molten metal, causing serious problems of environmental pollution due to dust scattering during the transport and operation into the molten metal. When storing the raw materials for passenger use in the storage container, entanglement occurs, which causes a problem of lowering workability.

Therefore, it is possible to obtain a temperature rising effect of the molten metal within a short time and to prevent environmental pollution problems such as dust scattering, so that a new molten metal heating agent which can replace the existing molten metal is required. As the manufacturing cost increases and the price competitiveness decreases, the manufacturing cost of steelmaking products is required to be reduced.

The present invention has a particle size of about 20mm to 50mm, there is no dust generation, does not cause problems of environmental pollution, no entanglement during storage, excellent workability, shorten the temperature rise time of the molten metal to improve the temperature rising efficiency It is an object of the present invention to provide a temperature rising briquette that can be made.

In addition, it is another object to reduce the production cost of steelmaking products and to prevent environmental pollution by recycling waste resources that are discarded when producing other products.

The present invention has been made in order to achieve the above object, the molten metal briquette for heating according to the present invention serves to raise the molten metal in the steelmaking process, the silicon content is discarded 50% by weight in the manufacture of other products 90 wt% to 98 wt% of waste silicon carbide (SiC), which is 80 wt%, and 2 wt% to 10 wt% of a mixture mixed with a binder, are manufactured to have a first particle size by compression molding. .

In this case, the molten metal briquette for heating, 45% to 76% by weight of silicon (Si), 17.55% to 48.02% by weight of carbon (C), 2% to 10% by weight of the binder component and And 0.45% by weight to 0.98% by weight of impurities, and the impurities include sulfur (S) and phosphorus (P).

In addition, the binder is characterized in that any one of an inorganic binder, an organic binder, a liquid sodium silicate (Sodium silicate), the small amount of nitric acid (nHNO ₃ ) and sodium hydroxide when the binder is a liquid sodium silicate. (NaOH) is further included, and self-heating after compression molding is characterized by rapid drying.

In addition, the first particle diameter is characterized in that the 20mm to 50mm.

The method for manufacturing a molten metal briquette for heating a molten metal according to the present invention comprises the steps of: collecting waste silicon carbide (SiC) having a silicon content of 50% to 80% by weight discarded in the manufacture of another product; Through the filtering process, the collected silicon content of low-grade silicon carbide (SiC) having 50% to 80% by weight of the first silicon carbide piece having a particle size of 10 mm or less and the second silicon carbide piece exceeding 10 mm Separating into; Performing a crushing process on the second silicon carbide piece having a particle size larger than 10 mm by using a crushing device to form a third silicon carbide piece having a particle size of 10 mm or less; Conducting a mixing process of stirring and mixing the first and third carbide pieces 90% to 98% by weight with the binder of 2% by weight to 10% by weight; Compression molding the silicon carbide mixture in which the first and third carbide pieces and the binder are mixed to have a first particle size; Drying the compression molded mixture.

At this time, the low-grade silicon carbide (SiC) having a silicon content of 50% by weight to 80% by weight during the manufacture of other products is characterized in that the silicon carbide discarded at the time of manufacturing high temperature abrasives, refractory, bearings and nozzles.

In addition, the molten briquette for heating the temperature is 45% to 78.4% by weight of silicon (Si), 17.55% to 48.02% by weight of carbon (C), 2% to 10% by weight of the binder component and And 0.45% by weight to 0.98% by weight of impurities, and the impurities include sulfur (S) and phosphorus (P).

As described above, the molten metal briquette for heating the molten metal according to the present invention comprises silicon carbide abrasives, refractory materials, nozzles, etc., characterized in that it contains 90% by weight or more of high purity silicon, and is relatively low purity silicon which is left to be discarded. By recycling the low-grade silicon carbide containing a predetermined binder by adding only a predetermined binder to recycle waste resources, there is an effect to prevent environmental pollution.

Briquettes using low-grade silicon carbide are used as substitutes for ferrosilicon, anthracite, and cost ingots, which are used as heating materials for molten metal, and have an effect of reducing the production cost of steelmaking products.

In addition, the briquette using low-grade silicon carbide has a particle size of 20 mm or more, so the amount of floating on the surface of the molten metal is small, thereby minimizing the consumption of oxidative calorific value into the air, thereby shortening the temperature raising time of the molten metal.

In addition, by forming a briquette having a particle size of 20mm or more, there is little dust generation compared to the conventional heating material having a size of 10mm or less, there is no entanglement during storage, and workability is excellent.

Figure 1a to 1d is a step-by-step process diagram of manufacturing a melt temperature increase briquette using waste silicon carbide according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described.

Silicon carbide (SiC) is composed of carbon compounds such as silicon (Si) and carbon (C) or silicon (Si) and pitch coke or petroleum coke, and has high temperature strength, wear resistance, oxidation resistance, corrosion resistance, and creep. ) It is a material widely used for manufacturing bearings, various nozzles, high temperature abrasives, and refractory materials due to its excellent properties such as resistance. At this time, the silicon carbide used in such a product is mainly used that the silicon (Si) content of more than 90% by weight, the silicon carbide having a relatively low content of silicon silicon content of less than 90% by weight has been disposed of.

The present invention is characterized in that for producing molten metal briquettes for use in steelmaking by using silicon carbide of low grade having a silicon content of less than 90% by weight, which is used for manufacturing other products.

That is, the molten metal heated briquette according to the present invention has a silicon content of 50% by weight to 80% by weight of a high temperature abrasive, a refractory, a bearing and a nozzle made of silicon carbide having a silicon content of 90% by weight or more. After recycling the low-grade silicon carbide to a predetermined size, it is characterized in that it is formed to have a particle size of about 20mm to 50mm by compression molding by mixing the binder with the crushed low-grade silicon carbide.

In this case, the molten metal heated briquette is made of low-grade silicon carbide discarded after manufacturing other products, so that a small amount of impurities are included to improve characteristics of other products. These impurities are about 0.5% to 1% by weight of the total content, and contains sulfur (S) and phosphorus (P).

Therefore, the molten metal briquette for heating according to the present invention is a mixture of 90% to 98% by weight of low-grade silicon carbide having a silicon content of 50% to 80% by weight, and 2% to 10% by weight of a binder. The content of silicon in the briquettes is 45% to 78.4% by weight, carbon is 17.55% to 48.02% by weight, and the components constituting the binder are 2% to 10% by weight, and the remaining impurities are 0.45% by weight. It is characterized by being from% to 0.98% by weight.

It can be seen that the melting temperature carbide having silicon carbide having such a content ratio as a main raw material has a melting point suitable for raising the temperature of the molten metal because its melting point is about 1300 ° C to 1700 ° C.

Silicon carbide having a silicon content of 99% by weight has a melting point of 3000 ° C, and a silicon carbide having a silicon content of 95% by weight has a melting point of 2400 ° C to 2500 ° C, and silicon carbide having such a silicon content ratio is too high It cannot be used because it has a melting point and does not substantially contribute to the elevated temperature of the melt. Therefore, silicon carbide having a silicon content of 90% by weight or more used in the manufacture of other products such as abrasives, refractory bearings, and nozzles may not be used because its melting point is too high even if it is substantially commercialized as a melt-heating briquette.

Therefore, the present invention has a specific size using a low-grade silicon carbide containing less than 90% by weight of silicon that is discarded because the silicon content is not used for these products after making these products, the melting point is 1300 It is characterized by the proposed briquette that can faithfully fulfill the role of the temperature rising to 1700 ℃ ℃.

By using waste resources, the molten metal temperature increase briquette according to the present invention significantly lowers the manufacturing cost of steelmaking products because the production cost thereof is much lower than that of commonly used molten metal temperature rising products, for example, ferrosilicon, coke, anthracite, and the like. In addition, by recycling the waste resources there is an advantage that can prevent the environmental pollution by waste disposal.

On the other hand, the molten briquette for raising the temperature using the low-grade silicon carbide according to the present invention contains a small amount of impurities such as sulfur (S), phosphorus (P) included to improve the properties of other products, such impurities are contained in the molten metal This is not a problem since the high temperature in the molten metal causes the particles to float or vaporize and be removed.

That is, a commonly used molten metal product for heating the temperature also includes a predetermined impurity, and a facility or a processor for removing impurities contained in these products is substantially installed around the molten metal, so that the bridging according to the present invention is Impurities contained in the ket are not a problem as they are treated by these treatment facilities.

Hereinafter, a method for manufacturing molten metal briquette using waste silicon carbide according to the present invention having the above-described configuration will be described.

Figure 1a to 1d is a step-by-step process chart of the production of melt briquettes using waste silicon carbide according to the present invention.

The waste silicon carbide used in the molten metal heating briquette according to the present invention will have various sizes because it is a waste material produced during manufacture of abrasives, refractory materials, bearings, and nozzles as an example of other products.

The waste silicon carbide having various sizes does not aggregate into briquettes having a particle size of about 20 mm to 50 mm even if the binder is mixed, and the silicon content of the pieces has been used to manufacture various products. Since the ratio is different, it cannot be briquetted as it is, and even if briquettes, since the large silicon content ratio is different for each briquette, it may play a role as a temperature increasing agent, which may cause a large deviation.

Therefore, in order to solve this problem, as shown in FIG. 1A, waste silicon carbide pieces having various sizes are preferentially treated with silicon carbide pieces 102 and dust having a particle size of 5 mm or less, as shown in FIG. The silicon carbide pieces 101 having the above particle size sizes are separated.

This filtering process simply passes through the mesh 105 using a mesh 107 having a square mesh 105 whose length is 5 mm (silicon carbide pieces 102 having a particle size of 5 mm or less). ) And the remaining ones (silicon carbide pieces 101 having a particle size larger than 5 mm) remaining without passing through the mesh 105, and the low-grade silicon carbide has a particle diameter of 5 mm due to the filtering process. It is separated into more than 101 and less than 102.

Next, as shown in FIG. 1B, the silicon carbide fragment 101 having a particle size of more than 5 mm separated by the filtering process is put into the shredder 109, and the particle size is smaller, preferably about 0.1 mm to 5 mm. Proceed with the shredding process to be.

In the present invention, for example, using a hopper 112, a crushing roll 110 (110a, 110b) having a pair of smooth surfaces, and a crusher 109 composed of a conveyor 114, the particle size of 5 mm or more is determined. Although the crushing of the low-grade silicon carbide pieces 101 is shown, other types of crushers may be used.

 The silicon carbide pieces 101 having a particle diameter of more than 5 mm introduced into the crusher 109 are crushed while passing through a pair of crushing rolls 110 (110a and 110b) that have a spaced interval smaller than 5 mm and rotate as engaged with each other. This results in a silicon carbide piece 104 having a size smaller than 5 mm in diameter.

After passing through the shredding roll 110, the silicon carbide piece 104 having a particle size smaller than 5 mm is dropped and positioned on the conveyor 114 positioned below the shredding roll 110. The conveyor 114 moves in one direction and is collected in the collecting means 116 such as a box placed at the end of the conveyor 114.

The silicon carbide pieces 104 collected and collected by the filtering process and the shredding process have a particle size of 10 mm or less, and the silicon carbide pieces 104 having a particle size of 5 mm or less have different pieces. Since low-grade silicon carbide, which is discarded after formation, is mixed, even if they have different silicon (Si) content ratios, they are evenly mixed by the process in the future, and finally, they are commercialized as briquettes having a particle size of 20 mm or more. The feature is that there is no variation in the silicon content.

Next, as shown in Figure 1c, the crushing process proceeds to the silicon carbide pieces (104 in Figure 1b) and dust having a particle size of 5mm or less, and the silicon carbide separated to have a particle size of 5mm or less already in the previous filtering process In the stirring device 120 having a piece (102 of FIG. 1A) (hereinafter referred to as a piece of mixed silicon carbide 105) and a rotating rod 124 having a plurality of rotating blades 122 with dust and a binder 115. The mixing process is performed so that the silicon carbide pieces 105 having a particle size of 5 mm or less and dust and the binder 115 are well mixed by adding and stirring at a suitable speed for a proper time.

At this time, when the rotation speed of the rotating rod 124 was stirred for about 3 minutes to 8 minutes in the range of 100rpm to 150rpm through the experiment, it can be seen that the silicon content ratio is well mixed with almost no deviation.

At this time, the silicon carbide fragment 105 and the binder 115 mixed with the dust may be used both organic and inorganic binders commonly used in the art. At this time, it is more preferable to use organic binders such as starch, molasses, and glue, which are volatilized into the air by oxidation in a furnace or an electric furnace during the steelmaking process rather than the inorganic binder.

Meanwhile, as the binder, liquid silicate (sodium silicate) called water glass, which is commonly used in briquette production, may be used, and for example, a small amount of nitric acid may be used for rapid drying of the finally formed briquette. Liquid binders having a self-heating function, including (nHNO ₃ ) and sodium hydroxide (NaOH), may also be used.

On the other hand, in the mixing ratio of the silicon carbide piece 105 and the dust and the caking agent 115 having a particle diameter of 5 mm or less, the silicon carbide piece 105 and the dust is 90% to 95% by weight, and the binder Preferably, 115 is from 2% by weight to 10% by weight. When the binder 115 is mixed at less than 2% by weight, the silicon carbide fragment 105 and the dust are not mixed well due to too little moisture or the adhesive property which is characteristic of the binder is small, and thus the particle size of 20 mm or more is finally reduced. Since the briquette having a low strength is low after the completion of the briquettes are easily broken because of the weak external impact, it is preferable to mix the binder in more than 2% by weight in order to weave.

Next, as shown in FIG. 1D, a silicon carbide mixture 130 having a silicon carbide fragment 130 having a particle diameter of 10 mm or less (105 in FIG. 1C) and dust and a binder (115 in FIG. 1C) is well mixed. a hopper 147 and a lower portion of the hopper 147 to the silicon carbide mixture 130 with recesses 140 in the form of hemispheres, semi-ellipses, and semi-polyhedra A pair of the pressing rolls 145 (145a, 145b) and a plurality of auxiliary rolls 137 below the pair of the pressing rolls 145, wherein the recesses are engaged and rotated. The object is placed in the briquetting device 150 including a conveyor 135 for moving in one direction.

At this time, the hopper 147 of the briquetting device 150 has a shape of the inlet and outlet, the inlet is a large area and the outlet is in the center of the contact portion of the pair of pressing rolls 145 in contact with each other Correspondingly, having a narrow area, the silicon carbide mixture 130 discharged through the outlet may pass through the pair of pressing rolls 145 well.

The silicon carbide mixture 130 introduced through the inlet of the hopper 147 of the briquetting device 150 is dropped to the center of the pair of pressing rolls 145 through the outlet of the hopper 147, The concave portion 140 formed on the pair of pressing rolls 145 is filled. At this time, when the pair of pressing rolls 145 rotate in contact with each other, the recesses 140 formed on the surfaces of the pressing rolls 145a and 145b are occluded, and the silicon filling the recesses 140 is filled. The carbide mixture 130 is pressurized.

Then, the silicon carbide briquette 132 formed in the form of a sphere, an ellipsoid, a polyhedron, a cylinder, and the like by passing through the contact portion of the pair of pressing rolls 145 to be occupied by its own weight It is dropped by the upper portion of the conveyor 135 located below, and moves along the conveyor 135 is placed inside the storage means 155, such as a box.

Then, the silicon carbide briquette 132 according to the present invention in a completely dried and cured state by proceeding the drying process through a drying apparatus (not shown) in a state settled in the storage means 155 or by leaving it at room temperature for a proper time. To complete).

Silicon carbide briquette 132 according to the present invention is characterized in that the particle diameter of 20mm to 50mm, 45% to 78.4% by weight of silicon (Si), 17.55% to 48.02% by weight of carbon (C) And 2 wt% to 10 wt% of a binder component and 0.45 wt% to 0.98 wt% of impurities. In this case, the impurities include sulfur (S) and phosphorus (P).

Briquette 132 using waste silicon carbide finished to have such a particle size is easy to pack and transport, and does not cause problems such as scattering when it is added to the molten metal, and has the advantage of smoothly raising the temperature of the molten metal. have.

On the other hand, the briquette 132 using waste silicon carbide according to the present invention can be commercialized in the form of less than the pieces and silicon content obtained during the appropriate molding process for manufacturing other products, such as abrasives, refractory, bearings and nozzles. It is characterized by the use of waste silicon carbide pieces and dust which are disposed of without waste.

Therefore, the low-grade silicon carbide collected to manufacture the melt-heating briquette 132 according to the present invention is used for the production of different products, so it is made of silicon carbide pieces having various silicon content ratios. As a result of the filtering process, the crushing process, and the mixing process of the binder as described above, the mixed silicon carbide has almost the same silicon content ratio, and thus the briquette 132 finally manufactured using the same has a variation in the silicon content ratio. It will have almost the same level of silicon content.

130: silicon carbide mixture 132: briquette
135: conveyor 137: secondary roll
140: recess 145 (145a, 145b): a pair of pressing rolls
147: Hopper 150: Briquetting device
155: storage means

Claims (10)

In playing a role of raising the molten metal in the steelmaking process,
A mixture of 90% to 98% by weight of low-grade silicon carbide (SiC) having a silicon content of 50% to 80% by weight, and 2% to 10% by weight of a binder, which is discarded in manufacturing other products, is mixed. It is produced to have a first particle size by compression molding, characterized in that the melt heated briquettes.
The method of claim 1,
The molten briquette for warming up,
45% to 78.4% by weight of silicon (Si), 17.55% to 48.02% by weight of carbon (C), 2% to 10% by weight of a binder component, and 0.45% to 0.98% by weight of impurities Briquette for warming up the temperature characterized by including a.
The method of claim 2,
The impurity is a briquette for melting the temperature, characterized in that containing sulfur (S) and phosphorus (P).
The method of claim 1,
The binder is an inorganic binder, an organic binder, liquid silicate (Sodium silicate), characterized in that any one of the temperature rising briquette.
The method of claim 1,
When the binder is liquid sodium silicate, molten nitric acid (nHNO ₃ ) and sodium hydroxide (NaOH) by further comprising a heat-generating briquette for the rapid drying by self-heating after compression molding.
The method of claim 1,
The first particle diameter is 20mm to 50mm molten ferrosilicon briquette for heating.
Collecting low grade silicon carbide (SiC) having a silicon content of 50% to 80% by weight discarded in the manufacture of another product;
The filtering process is performed to obtain a low-grade silicon carbide (SiC) having a silicon content of 50% to 80% by weight, and the first silicon carbide piece having a particle size of 10 mm or less and the second silicon carbide exceeding 10 mm Separating it into pieces;
Performing a crushing process on the second silicon carbide piece having a particle size larger than 10 mm by using a crushing device to form a third silicon carbide piece having a particle size of 10 mm or less;
Carrying out a mixing process of stirring and mixing the first and third carbide pieces 90% to 98% by weight with the binder of 2% by weight to 10% by weight;
Compression molding the silicon carbide mixture in which the first and third carbide pieces and the binder are mixed to have a first particle size;
Drying the compression molded mixture
Briquette production method for heating the molten metal comprising a.
The method of claim 7, wherein
Low-grade silicon carbide (SiC) having a silicon content of 50% to 80% by weight discarded in the manufacture of other products is characterized in that the silicon carbide discarded in the manufacture of high temperature abrasives, refractory, bearings and nozzles Way.
The method of claim 7, wherein
The molten briquette for warming up,
45% to 78.4% by weight of silicon (Si), 17.55% to 48.02% by weight of carbon (C), 2% to 10% by weight of a binder component, and 0.45% to 0.98% by weight of impurities Method for producing a molten metal briquette for heating characterized in that it comprises a.
The method of claim 9,
The impurity is a manufacturing method of a molten metal briquette for heating, characterized in that containing sulfur (S) and phosphorus (P).

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