KR20140146832A - Method for abrasion resistive pipe of by-product - Google Patents

Abstract

The present invention relates to a pipe and a manufacturing method thereof. A pipe body is manufactured by mixing a slag generated in a steel production process and industrial byproducts, and includes the main components including: 45-50 wt% of silica (SiO_2), 10-15 wt% of iron oxide (Fe_2O_3), 7-12 wt% of aluminum oxide (Al_2O_2), 5-10 wt% of calcium oxide (CaO), and 15-20 wt% of magnesium oxide (MgO), and impurities that are unavoidably mixed. The pipe with excellent wear resistance and corrosion resistance is manufactured by the processes including: a process of preparing slag and industrial byproducts generated in a steel manufacturing process; a process of weighting the slag and the byproducts, and controlling a composition ratio; a process of mixing the slag and the byproducts; a process of melting a composition; a process of warming a melt; a process of centrifugally casting the melt in a pipe shape; and a process of heat-treating the cast material. Accordingly, basalt which is conventionally used to manufacture a high-strength pipe can be replaced to protect a natural ore basalt, thereby reducing the costs of imported raw materials for the pipe. Also, the costs to dispose and bury various slag and industrial byproducts can be reduced, and the pipe can be manufactured at low costs since slag production is sufficient.

Description

Technical Field [0001] The present invention relates to a pipe and a manufacturing method thereof,

The present invention relates to a pipe and a method of manufacturing the same, and more particularly, to a method of manufacturing a pipe having excellent wear resistance and corrosion resistance by utilizing slag generated in a steel mill and industrial by-products generated from a thermal power plant.

The iron and steel industry is producing a large amount of various kinds of by-products and wastes through the production of steel by consuming a large amount of raw materials and energy, as well as through a complex connection production system of raw materials, steel making, steel making and rolling. These by-products and wastes amount to as much as 65% of the main steel product. About 80% of the solid state by-products and waste are slag, and the remainder are by-products generated from the thermal power plant. Most of these industrial by-products have high iron content and can be utilized as most resources.

Generally, in the process of producing 1 ton of steel material, steelmaking slag of 100 to 500 kg is generated. For example, the slag of ferronickel (Fe-Ni) is more than 1 million ton per year, and fly ash, which is an industrial by-product, is generated by Hadong thermal power plant and generates 1.3 million tons per year. The slag thus generated is dumped into the yard, cooled in the atmosphere together with a large amount of waterproofing and solidified, and the solidified slag mass is recycled as cement raw material or the like. However, it is sometimes buried and processed according to the market situation, and it is not good to increase the cost or create the use as a material.

On the other hand, Basalt products made by melting basalt at high temperature are commonly used for high-strength pipes having excellent abrasion resistance. Basalt products are produced by completely melting basalt in a melting furnace at 1280 ° C, casting it into a pipe-shaped product by centrifugal casting at 1200 ° C, and recrystallizing it through a cooling pattern.

Basalt pipes are used in transport pipelines for pressure and water pressure in industries such as steelworks, power plants, and gas plants because of their excellent abrasion resistance and corrosion resistance. However, And the like, and only the internal treatment is performed using mortar or the like in the piping line.

Therefore, it is required to study the method of manufacturing pipes using slag and industrial byproducts generated in the steel manufacturing process in order to replace expensive products.

KR 1984-0007610 A1

The present invention provides a pipe similar to a bar-cut pipe and a method of manufacturing the same, by using various slags and industrial by-products, and having excellent abrasion resistance and corrosion resistance.

The present invention provides a pipe capable of preventing the use of basalt, which is a natural ore, and a method of manufacturing the same.

The present invention provides a pyroxene crystal phase, that is, a pipe having an augite and an enstatite crystal phase, and a method for producing the same.

The pipe body is manufactured by mixing slag and industrial byproducts generated during a steel production process, the pipe body comprising 45 to 50 wt% silicon dioxide (SiO ₂ ), 10 to 15 wt% iron oxide (Fe ₂ O ₃ ), 7 to 12 wt% aluminum oxide (Al ₂ O ₃ ), 5 to 10 wt% calcium oxide (CaO) and 15 to 20 wt% magnesium oxide (MgO), and other inevitably mixed Contains impurities.

The slag includes ferronickel slag and converter slag, and the industrial by-products may include fly ash.

The ratio of the ferronickel slag to the converter slag and the fly ash may be in the range of 45 to 55 wt%, 10 to 20 wt%, and 30 to 40 wt%, respectively, by weight.

The pipe body may have a basicity ((CaO + MgO) / SiO ₂ ) of 0.45 to 0.55 or less.

The pipe body may include a crystalline phase of a pyroxene system.

The pipe body may comprise an augite or enstatite crystalline phase.

A method of manufacturing a pipe according to an embodiment of the present invention includes the steps of preparing slag and industrial byproducts generated during the steel manufacturing process, measuring the slag and the byproducts, controlling the composition ratio, blending the slag and the by- A process of melting the composition, a process of keeping the melt warm, a process of centrifugally casting the melt into a pipe shape, and a process of heat treating the molded product.

The slag includes a ferronickel slag and a converter slag, and the by-product includes fly ash, and the composition can be used in combination with the ferronickel slag, the converter slag, and the fly ash.

The process of controlling the composition ratio may include controlling the composition ratio of silicon dioxide (SiO ₂ ) of 45 to 50 wt%, iron oxide (Fe ₂ O ₃ ) of 10 to 15 wt%, aluminum oxide (Al ₂ O ₃ ) of 7 to 12 wt% 5 to 10% by weight of calcium oxide (CaO) and 15 to 20% by weight of magnesium oxide (MgO).

The basicity ((CaO + MgO) / SiO ₂ ) of the composition can be maintained in the range of 0.45 to 0.55 or less.

The process of inserting the melt may be performed in the range of 1200 to 1250 ° C.

The centrifugal casting process includes injecting the melt into a mold, and the mold may be preheated before injecting the melt.

The preheating temperature range of the mold may be between 300 and 400 < 0 > C.

The centrifugal casting process may include cooling the inside of the mold during the casting process.

The centrifugal casting process may include extracting the shaped material from the centrifugal casting machine at a temperature ranging from 900 to 1100 占 폚.

The step of heat-treating the molded article may include an annealing step of keeping the molded article at a temperature lower than the crystallization temperature.

The heat treatment process may include a sub-annealing step of keeping the molded article at a temperature higher than the glass transition temperature before the annealing step.

After the heat treatment, the molded product is cooled, and the molded product can be cooled at a rate of 0.5 to 1.0 ° C per minute.

Wherein the annealing temperature is within a range from a temperature lower than the crystallization temperature by 100 占 폚 to the crystallization temperature and the sub annealing temperature is within a range from a temperature 20 占 폚 higher than the glass transition temperature to a temperature 50 占 폚 higher than the glass transition temperature .

According to the pipe and the method for manufacturing the pipe according to the embodiment of the present invention, the pipe having excellent wear resistance and corrosion resistance is manufactured by using the slag generated in the steel production process and industrial by-products of the thermal power plant. Pipes made from such compositions have a pyroxene-based crystalline phase (i.e., augite and enstatite) similar to the composition of a conventional bazaar pipe. Accordingly, since pipes manufactured using various slags and industrial by-products as raw materials can replace the bar-alt pipe, it is possible to prevent consumption of raw materials used for manufacturing the bar-alt pipe in the related art. That is, it is possible to protect the basalt which is a natural ore by replacing the basalt which is conventionally used for manufacturing the bar-alt pipe, and it is also possible to reduce the raw material burden of the imported high-strength pipe.

In addition, various slags and industrial by-products can be expanded to pipes used in various piping lines in addition to being used for landfill purposes, cement raw materials, and the like. Therefore, it is possible to create new products with high profitability with high added value by utilizing various kinds of slag and industrial byproducts which are buried more than 1 million tons a year.

Also, it is possible to save costs for disposal or landfilling of various slag and industrial by-products, and since the production amount of slag is abundant, it is possible to mass-produce pipes with excellent wear resistance and corrosion resistance at low cost. In addition, it does not emit harmful substances and is harmless to the human body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart showing a pipe manufacturing method according to an embodiment of the present invention.
Fig. 2 is a view schematically showing the pipe manufacturing method of Fig. 1. Fig.
3 is a view showing raw material composition ratios and processing conditions of the composition according to an embodiment of the present invention.
4 is a graph showing a TG-DTA pattern of a pipe composition according to an embodiment of the present invention.
5 is a graph showing a heat treatment pattern according to an embodiment of the present invention.
6 is a table showing strength and abrasion characteristics of an embodiment of the present invention and a conventional pipe.
7 is a photograph showing a pipe according to an embodiment of the present invention.

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. It is to be understood that the invention is not limited to the disclosed embodiments, To be provided. Wherein like reference numerals refer to like elements throughout.

The pipe according to the embodiment of the present invention is manufactured by mixing slag and industrial byproduct generated during the production process of steel and is made of a pipe body for use in various piping lines. Here, the composition is produced by making slag and industrial by-products into a powder form and blending raw materials at a predetermined composition ratio. This is because the composition ratio of the composition is set so that the pipe to be produced has a crystalline phase of a pyroxene system, that is, an augite or enstatite crystalline phase.

Slag ( Slag )

Slag is a by-product of producing steel products from natural resources such as iron ore, coal and limestone. The slag used in the embodiment of the present invention is ferroalloy slag (Fe-Ni slag) produced as a by-product in an iron-nickel alloy manufacturing process and a converter slag produced as a by-product in a steelmaking process for refining a molten steel of a converter with steel.

On the other hand, ferro nickel slag and converter slag is fluorine (F), phosphorus pentoxide (P ₂ O _5), chromium ocher (Cr ₂ O3), nickel oxide (NiO) as a component that is inevitably contained and other components or impurities in addition to the main component and it may include copper oxide (CuO), zinc oxide (ZnO), strontium (SrO), and zirconium oxide (ZrO _2), pentoxide, niobium (Nb ₂ O _5), sulfur (P), carbon (C), etc. .

Fly ash Fly ash )

Fly ash is a particulate industrial by-product that is collected by a dust collector of a pulverized coal combustion boiler among coal ash generated from a coal-fired thermal power plant. The main component is SiO ₂ , Al ₂ O ₃ , vitreous and has a spherical shape. Fly ash can also be mixed with cement and used as fly ash cement.

The following is an exemplary description of the main chemical composition of various slag and industrial by-products and a bazaar product with reference to Table 1.

division SiO ₂ (wt%) Fe ₂ O ₃ (wt%) Al ₂ O ₃ (wt%) CaO (wt%) MgO (wt%) Ferronickel
Slag 53.5 11.7 2.2 0.3 31.1 Converter slag 8.9 29.9 1.7 46.1 9.8 Fly ash 62.5 4.2 22.0 3.9 1.1 Basalt products 46.4 12.3 11.2 11.2 11.5

As shown in Table 1, the main chemical composition of ferronickel slag, converter slag and fly ash, and the chemical composition of the basalt product are similar to each other only in content of each component. In other words, each slag and fly ash is composed of silicon dioxide (SiO ₂ ), iron oxide (Fe ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), calcium oxide (CaO) and magnesium oxide ), And the contents of the main components differ depending on the raw materials.

The reason why the composition of the raw materials is important is that the composition ratio of the composition is set so that a pipe having a pyroxene-based crystalline phase (i.e., augite or Enstatite) similar to the composition of the Baasalt product is prepared and the ferronickel slag, . Therefore, the composition ratio of the main elements will be described in detail below.

Next, a composition prepared by blending ferronickel slag, converter slag, and fly ash will be described.

The weight ratio of the composition used in the pipe production of the present invention is such that the ratio of the ferronickel slag, the converter slag and the fly ash are respectively 45 to 55 wt%, 10 to 20 wt% and 30 to 40 wt% .

The composition ratio of each raw material composition is 45 to 50 wt% of silicon dioxide (SiO ₂ ), 10 to 15 wt% of iron oxide (Fe ₂ O ₃ ), 7 to 12 wt% of aluminum oxide (Al ₂ O ₃ ) , Calcium oxide (CaO) in an amount of 5 to 10% by weight, and magnesium oxide (MgO) in an amount of 15 to 20% by weight. Further, the pipe having the composition ratio has a basicity ((CaO + MgO) / SiO ₂ ) of 0.45 to 0.55 or less.

Hereinafter, the meaning of the content range of the above-mentioned components will be described.

Silicon dioxide ( SiO ₂ )

If the silicon dioxide (SiO ₂ ) is contained in an amount less than 45% by weight, cracks are generated in the final product pipe after the heat treatment or heat treatment. If the silicon dioxide (SiO ₂ ) is contained in an amount exceeding 55% by weight, Therefore, it is preferable to contain 45 to 55% by weight.

Iron oxide ( Fe ₂ O ₃ )

Iron oxide (Fe2O3) functions as an inoculum for nucleation and affects the strength of the product. If iron oxide is contained in an amount of less than 10% by weight, nucleation is insignificant, and if it is contained in an amount exceeding 15% by weight, cracks may occur in a manufacturing process or a product after manufacture. Therefore, the iron oxide in the whole composition of the composition preferably contains 10 to 15% by weight.

Aluminum oxide ( Al ₂ O ₃ )

Aluminum oxide (Al ₂ O ₃ ) affects the function of lowering the melting point of the composition and the viscosity when the composition is in a molten state. If aluminum oxide is contained in an amount of less than 7% by weight, it is difficult to reduce the melting point of the composition, so that the composition is not easily melted. If the aluminum oxide is contained in an amount of more than 12% by weight, the viscosity of the composition increases, . Therefore, it is preferable that aluminum oxide in the entire composition of the composition contains 7 to 12% by weight.

Calcium oxide ( CaO ), Magnesium oxide ( MgO )

Calcium oxide (CaO) and magnesium oxide (MgO) control the basicity of the composition. It is preferable that the basicity (CaO + MgO) / SiO ₂ is in the range of 0.45 to 0.55. When the basicity is less than 0.45, cracks are generated or broken in the manufacturing process or after the production, and if the basicity value exceeds 0.55, the product is deformed. Accordingly, it is preferable that the composition contains 5 to 10% by weight of calcium oxide and 15 to 20% by weight of magnesium oxide.

The slag and the industrial by-products generated from the thermal power plant are mixed in a powder form so that the slag and the by-product generated in the steel production process have a predetermined weight ratio and composition ratio. The final pipe is a pyroxene- Augite crystalline and enstatite crystalline phases.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart showing a pipe manufacturing method according to an embodiment of the present invention. Fig. 2 is a view schematically showing the pipe manufacturing method of Fig. 1. Fig. 3 is a view showing raw material composition ratios and processing conditions of the composition according to an embodiment of the present invention. 4 is a graph showing a TG-DTA pattern of a pipe composition according to an embodiment of the present invention. 5 is a graph showing a heat treatment pattern according to an embodiment of the present invention. 6 is a table showing strength and abrasion characteristics of an embodiment of the present invention and a conventional pipe. 7 is a photograph showing a pipe according to an embodiment of the present invention.

Referring to FIG. 1, a method of manufacturing a pipe according to an embodiment of the present invention includes the steps of preparing slag and industrial byproducts generated during a steel manufacturing process, measuring slag and byproducts, controlling a composition ratio, A process of melting the composition, a process of keeping the melt warm, a process of centrifugally casting the melt into a pipe shape, and a process of heat treating the molded product.

First, the ferronickel slag, converter slag, and fly ash generated from the thermal power plant generated during the steel manufacturing process are dried to prepare the raw material at a temperature of 100 ° C or higher. At this time, the ferronickel slag, converter slag, and fly ash are prepared in powder form to facilitate melting (S100). For example, the ferronickel slag and the converter slag may be pulverized to a predetermined particle size (for example, 5 mm or less) to have a powder form. At this time, since the fly ash is generally in the form of powder, a special pulverization or separation process may not be required.

Next, raw materials prepared in powder form are measured and the composition ratio is controlled (S200). For example, in the weight ratio of the entire composition, 45 to 55 wt% of the powder of ferronickel slag, 10 to 20 wt% of the converter slag powder and 30 to 40 wt% of the flyash powder are prepared, The raw material is controlled so as to have the composition ratio described above. At this time, in controlling the composition ratio, the composition is controlled to have a range of 0.45 to 0.55 so that the basicity ((CaO + MgO) / SiO ₂ ) is similar to the Baasalt product. That is, the range of basicity can inhibit or prevent problems that may occur in the manufacturing process or in the pipe after manufacture as described previously.

After the basicity is controlled by controlling the composition ratio, the controlled material is mixed (S300). For example, ferronick slag, converter slag, and fly ash, which are respectively provided in powder form, may be put into the kneader and blended at the basic blending ratio described above.

When the compounded composition is prepared, the composition is charged into the melting furnace, and the melting furnace is heated to the complete melting temperature of the composition to completely melt the composition (S400). At this time, the composition is charged into the melting furnace 100 heated to a temperature of 1200 ° C or higher, and the melting furnace 100 is heated to 1400 ° C or higher for complete melting, and is completely melted and homogenized. Here, it is possible to flow out based on the melting point of the raw material constituting the composition in order to determine the complete melting temperature. For example, the melting point of ferronickel slag is 1410 ° C, the melting point of the converter slag is 1380 ° C, and the melting point of fly ash is 1385 ° C. Therefore, in the embodiment of the present invention, a temperature of 1400 캜 or more is used as the complete melting temperature of the bobbin.

When the composition is completely melted, a process of warming the melt before tapping is performed (S500). At this time, it is preferable to store the melted material in the warming furnace 200 maintained at a temperature within the range of 1200 to 1250 ° C. Such a range of the keeping temperature is an optimal condition in which iron oxide (Fe ₂ O ₃ ) in the melt can act as a nucleation site, and it is easy to crystallize the inside and the surface of the pipe.

Next, the molten material is introduced into a casting machine having a shape to be manufactured, and the pipe is centrifugally cast (S600). At this time, the molten material may be introduced directly into the centrifugal casting machine 400 using the ladle 300 between the warming furnace 200 and the mold 400.

At this time, the centrifugal casting method can be formed into a pipe shape by extruding the molten material by using any one of the casting methods such as an end casting method, a semi-centrifugal casting method, and a centri fusing method. At this time, the rotation speed of the centrifugal casting may be in the range of 600 to 700 rpm so that thermal deformation does not occur depending on the thickness of the pipe.

On the other hand, the mold of the centrifugal casting machine 400 is a tube-shaped mold for casting a pipe, and the inside thereof may be made of a refractory material and the outside may be made of a metal material such as cast iron.

In addition, a step of preheating the mold and the injection port may be included before the melt is injected into the casting mold in the process of casting the pipe. This is because the glass surface is formed on the surface of the pipe by the temperature of the molten material flowing into the mold and the injection port and the surface temperature difference between the mold and the injection port, so that the strength and wear resistance of the pipe can be reduced. At this time, the preheating temperature of the mold and the injection port is preferably 300 to 400 占 폚.

And cooling the inside of the tubular mold to suppress or prevent cracking of the pipe and flow of the inner and outer surfaces due to the temperature difference between the completely molten composition flowing into the process of casting the pipe and the temperature of the mold itself . At this time, various methods can be used for cooling the mold. For example, the inner surface of the mold can be uniformly cooled by spraying water or gas with a porous injection nozzle.

Also, during the process of casting the pipe, when the molded product reaches the desired shape, it may be separated from the centrifugal casting mold in the range of 900 to 1100 占 폚 to prevent cracking and spilling of the pipe.

After the above-described process, a heat treatment process is performed in the heat treatment furnace of the molded product (S700). Wherein the heat treatment process may include an annealing step that is maintained at a temperature below the crystallization temperature of the molding. It may also include a sub-annealing step to maintain the mold at a temperature above the glass transition temperature prior to the annealing step. Here, the holding time of the annealing or sub-annealing is proportional to the thickness of the molding, and after the heat treatment, the molding is cooled at a rate of 0.5 to 1.0 DEG C per minute.

The annealing temperature is in the range from the temperature lower than the crystallization temperature by 100 占 폚 to the crystallization temperature, and the sub-annealing temperature is within the range from the glass transition temperature to the glass transition temperature by 20 to 50 占 폚 higher than the glass transition temperature. At this time, when the annealing is carried out at a crystallization temperature or higher, the strength of the product may become weak due to overgrowth of crystals. In addition, when annealing is performed at a temperature lower than the glass transition temperature, the possibility that a large amount of glassy material is formed in the structure increases, and the strength of the product may become weak.

As such, the Fusion-CAST method can be used as the annealing step annealing method, and the glass ceramics method can be used as the annealing step and the annealing step annealing method.

On the other hand, the thermal analysis of the pipe making composition was performed as shown in FIG. Thermogravimetry (TG) and differential thermal analytical (DTA) were performed by thermal analysis. That is, the glass transition temperature and the crystallization temperature as shown in FIG. 4 can be observed by observing the change of the temperature with time while measuring the temperature of the composition.

Referring to Figure 4, by way of example, the glass transition temperature of the composition is about 730 ° C and the crystallization temperature is about 930 ° C. The glass transition temperature (glass transition temperature) means the center of a temperature region where an amorphous solid changes from a loose state such as glass to a viscous state, and a crystallization temperature Tc is a peak at which the rate at which crystal is generated becomes maximum Quot; means the temperature at the pole of.

The heat treatment process will be described in detail with reference to FIGS. 5 and 6. FIG. Referring to Figure 5, graphs of the Glass ceramics method and the Fusion-CAST method are shown, respectively.

In the Fusion-CAST method, a completely molten melt and molds of various shapes are held in a heat treatment furnace at a temperature lower than the crystallization temperature for 1 to 6 hours, and then heat-treated at a temperature of 0.5 to 1 DEG C per minute to 200 DEG C It proceeds. For example, the heat treatment may be performed in a heat treatment furnace at a temperature of 830 ° C for 1 to 6 hours and then cooled to 200 ° C at a temperature of 0.5 to 1 ° C or less per minute. This means that there is no sub-annealing temperature and the annealing process proceeds only with the annealing temperature.

In the glass ceramics method, the completely melted melts and the molds of various shapes are kept at the glass transition temperature for 1 hour, then heated to the temperature below the crystallization temperature, held for 1 to 6 hours, Lt; RTI ID = 0.0 > 200 C. < / RTI > For example, the temperature may be maintained at 750 to 780 占 폚 for 1 hour, then raised to 830 占 폚, held for 1 to 6 hours, and then cooled to 0.5 to 1 占 폚 per minute to 200 占 폚. That is, the annealing process proceeds at a sub-annealing temperature and an annealing temperature.

Further, the time at which the temperature is maintained at a temperature near the crystallization temperature is proportional to the thickness of the pipe to be manufactured. For example, if the thickness is 20 mm, the holding time can be determined to be about 3 hours.

When the heat treatment is completed as described above, the pipe is taken out from the heat treatment furnace 500 at a temperature of 100 DEG C or lower. It is preferable that the temperature is lower than the above temperature in order to suppress or prevent the change of the physical properties of the pipe due to the rapid temperature change. The pipe can then be surface-polished with a diamond grinder. Referring to FIG. 6, a table comparing the compression strength and the wear rate of the finally produced pipe with the existing barbed pipe can be seen. At this time, the compressive strength means the maximum compressive stress that the material can withstand without being broken.

In general, the bar-sheath pipe has a compressive strength of 300 MPa, and the wear rate shows a value close to 1.0%. Meanwhile, the compressive strength of the pipe according to the embodiment of the present invention shows a compressive strength of 320 to 400 MPa and a wear rate of 0.3 to 0.8%.

Thus, it can be seen that the pipe shown in FIG. 7 produced by using slag and fly ash exhibits a compressive strength similar to or higher than that of the existing barbed pipe, and the abrasion rate is lower than that of the barbed pipe.

As described above, in the method of manufacturing pipes and pipes according to the embodiment of the present invention, slag generated during the steel production process and fly ash, which is an industrial by-product, are used to have a crystal phase of a pyroxene system similar to that of a conventional bar- Can be replaced with a bar-taff pipe.

Therefore, it is possible to protect the basalt by preventing the use of the basalt, which is a natural ore used in the production of the basalt pipe, and to reduce the burden on the raw materials of the imported high strength pipe.

Although the present invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the present invention is not limited thereto but is limited by the following claims. Accordingly, those skilled in the art will appreciate that various modifications and changes may be made thereto without departing from the spirit of the following claims.

P: pipe 100: melting furnace
200: thermal insulation furnace 300: ladle
400: Centrifugal casting machine 500: Heat treatment furnace

Claims (19)

As a pipe,
The pipe body is manufactured by mixing slag and industrial by-products generated during the steel production process,
Wherein the pipe body comprises 45 to 50 wt% silicon dioxide (SiO ₂ ), 10 to 15 wt% iron oxide (Fe ₂ O ₃ ), 7 to 12 wt% aluminum oxide (Al ₂ O ₃ ) Pipes containing calcium oxide (CaO) in weight percent and major components of 15 to 20 weight percent magnesium oxide (MgO) and other inevitably mixed impurities. The method according to claim 1,
Wherein the slag comprises a ferronickel slag and a converter slag, and the industrial by-product comprises fly ash. The method of claim 2,
The ratio of the ferronickel slag to the converter slag and the fly ash is, by weight,
45 to 55% by weight, 10 to 20% by weight and 30 to 40% by weight, respectively. The method according to at least one of claims 1 to 3,
Wherein the pipe body has a basicity ((CaO + MgO) / SiO ₂ ) of 0.45 to 0.55 or less. The method of claim 4,
Wherein the pipe body comprises a crystalline phase of a pyroxene system. The method of claim 5,
Wherein the pipe body comprises an augite or enstatite crystalline phase. A pipe manufacturing method,
The process of preparing slag and industrial byproducts generated during the steel production process;
Measuring the slag and the byproducts and controlling the composition ratio;
Mixing the slag and the by-product;
Melting the composition;
The process of keeping the melt warm;
A process of centrifugally casting the melt into a pipe shape; And
And heat treating the molded product. The method of claim 7,
Wherein the slag comprises a ferronickel slag and a converter slag, the by-product comprising fly ash,
Wherein the composition is used in combination with the ferronickel slag, the converter slag, and the fly ash. The method of claim 7,
The process of controlling the composition ratio may include controlling the composition ratio of silicon dioxide (SiO ₂ ) of 45 to 50 wt%, iron oxide (Fe ₂ O ₃ ) of 10 to 15 wt%, aluminum oxide (Al ₂ O ₃ ) of 7 to 12 wt% (CaO) and 15 to 20% by weight of magnesium oxide (MgO). The method of claim 9,
Wherein the basicity ((CaO + MgO) / SiO ₂ ) of the composition is maintained in the range of 0.45 to 0.55 or less. The method of claim 7,
Wherein the step of inserting the melt is performed in the range of 1200 to 1250 占 폚. The method of claim 7,
Wherein the centrifugal casting process comprises injecting the melt into a mold, and preheating the mold prior to injecting the melt. The method of claim 12,
Wherein the preheating temperature range of the mold is 300-400 占 폚. The method of claim 7,
Wherein the centrifugal casting process includes cooling the inside of the mold during the casting process. The method according to at least one of claims 7, 12 and 14,
Wherein the centrifugal casting process includes the step of withdrawing the shaped material from the centrifugal casting machine at a temperature in the range of 900 to 1100 占 폚. The method of claim 7,
Wherein the step of heat-treating the molded product comprises an annealing step of keeping the molded product at a temperature lower than the crystallization temperature. 18. The method of claim 16,
Wherein the annealing step comprises a sub-annealing step for maintaining the shaped article at a temperature above the glass transition temperature before the annealing step. The method according to claim 16 or 17,
A step of cooling the formed product after the heat treatment,
Wherein the molding is cooled at a rate of 0.5 to 1.0 DEG C per minute. 18. The method of claim 17,
Wherein the annealing temperature is within a range from a temperature lower than the crystallization temperature by 100 占 폚 to the crystallization temperature,
Wherein the sub-annealing temperature is within a range from a temperature 20 占 폚 higher than the glass transition temperature to a temperature 50 占 폚 higher than the glass transition temperature.

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