KR101088183B1 - Synthetic method of portland cement by using the heat and elements of the fused blast furnace slag and portland cement manufactured with this - Google Patents

Abstract

The present invention relates to a portland cement manufacturing method using molten blast furnace slag and a portland cement produced by the same, which is a main component of the portland cement clinker contained in the hot molten blast furnace slag discharged in the process of manufacturing molten iron in a blast furnace (blast furnace). The present invention relates to a method for producing portland cement using components (CaO, SiO ₂ , Al ₂ O ₃ , Fe ₂ O _3, etc.) and hot sensible heat of molten blast furnace slag. To this end, the present invention is a Ca component (lime raw material) feed material that is insufficient in molten blast furnace slag generated in the molten iron manufacture of limestone, waste lime, cement kiln dust and Fe components (iron raw material) as a feed material such as steelmaking slag and iron ore Is added, and the energy for Portland cement clinker mineral synthesis is reacted for 5 ~ 60 minutes while maintaining the temperature above 1,400 ℃ by utilizing molten blast furnace slag sensible heat and external supply energy.C ₃ S, C ₂ S, C ₃ This is a method for synthesizing the main minerals of Portland cement clinker such as A, C ₄ AF. In addition, the sensible heat recovered when cooling the clinker is recycled to steel processes such as iron ore drying, and at least one gypsum selected from phosphate, titanium, desulfurized, and natural gypsum (CaSO _{4 ·} 2H) in the cooled Portland cement clinker. _It is comprised by the process of crushing by adding 2O).

Molten Blast Furnace Slag, Portland Cement, Clinker Minerals, Limestone, Steelmaking Slag

Description

Portland cement manufacturing method using molten blast furnace slag {SYNTHETIC METHOD OF PORTLAND CEMENT BY USING THE HEAT AND ELEMENTS OF THE FUSED BLAST FURNACE SLAG AND PORTLAND CEMENT MANUFACTURED WITH THIS}

The present invention relates to a method for manufacturing portland cement using molten blast furnace slag and to a portland cement produced therefrom. More specifically, the present invention relates to a portland cement clinker contained in a high temperature molten blast furnace slag discharged in the process of manufacturing molten iron in a blast furnace. constituents _{(CaO, SiO 2, Al 2} O 3, Fe 2 O 3 , etc.) and reduce the Portland cement manufacturing costs through reduction of by utilizing sensible heat energy and raw material for the high temperature and suppress the greenhouse gas CO ₂ (g) emission It relates to a portland cement manufacturing method using a molten blast furnace slag having an effect to and a portland cement produced through the same.

Due to the nature of the manufacturing process, the steel industry not only uses a large amount of raw materials and energy, but also generates various kinds of waste and Busan resources.

In other words, the steel process generates a large amount of by-products and wastes through a complex production system of raw materials, steelmaking, steelmaking, rolling and stainless steel, and slag is the most by-product.

Steel slag is generated from blast furnace slag generated from the iron making process of iron ore, coke and limestone in the blast furnace to produce pig iron, converter slag generated from the steelmaking process to produce steel from the converter and electric furnace using scrap iron as the main raw material. It can be divided into electric furnace slag and the like.

In the steel industry, raw material prices and energy prices have a huge impact on production costs. Many countries are making efforts to manage energy rationally in the steel industry. One of them is research and development to recover energy emitted from various processes. It is actively underway.

The energy emitted from the steel industry refers to the energy that is not reused in the thermal energy or pressure energy of each product or by-product of each unit process. However, much of the energy that can be recovered and recycled is being thrown away.

In the field of energy recovery technology, a representative field which has not been developed until the practical use stage is a technology for recovering sensible heat of blast furnace or converter slag.

When producing 1 ton of pig iron in the blast furnace, about 300 kg of blast furnace slag is generated. Its discharge temperature is about 1,400 ℃ and above, and it has enormous sensible heat of about 374 (solid) to 455 kcal (liquid) per kg of blast furnace slag. However, at present, molten blast furnace slag is slowly cooled to crystallize the blast furnace slag, which is crystallized and used as aggregate, or quenched slag quenched with water to be used as cement admixture, cement raw material, fertilizer, etc. For this reason, the enormous amount of sensible heat (about 374 kcal / kg) contained in the molten blast furnace slag is not recycled and is being discarded.

On the other hand, Portland cement by Rotary Kiln was invented by Joseph Aspidin in 1824, and after World War II, as the reconstruction of the land and the economy grew rapidly, the demand for cement increased rapidly. Manufacturing methods have also changed in many ways to this day.

At first, dry short kilns equipped with thermal power generation facilities were the mainstream, but through wet long kilns and Lepol kilns, it has now become the era of dry SP (kip-spension preheater) kilns, which have low heat consumption and have high mass production effects. It is being converted to a new suspension preheater (NSP) kiln with a calciner.

The manufacture of Portland cement is roughly divided into three processes: raw material process, firing process and grinding process. The raw material process is a process in which limestone, clay, silica, iron oxide raw materials, etc. are dried, mixed at an appropriate ratio, finely pulverized in a raw material mill, and mixed uniformly. In the following firing process, the raw material mixture is supplied to a rotary kiln via a suspension preheater, fired at a high temperature of 1,400 ° C. or higher, and then quenched in a cooler to produce a portland cement clinker. The crushing process is a process for producing portland cement by pulverizing with a cement mill by adding an appropriate amount of gypsum to the Portland cement clinker as a coagulation delay agent. At this time, about 70% or more of the cement manufacturing cost is an energy cost in a cement plant, which is a typical energy-consuming industry like a blast furnace.

Table 1 shows the theoretical calories produced during the production of 1 kg of Portland cement clinker. The calories required to produce 1 kg of Portland cement clinker is about 420 kcal / kg clinker.

In actual Portland cement production, however, there are also heat losses through the exhaust gas and heat dissipation from the furnace, which is higher than the theoretical value. Total heat consumption (THC) actually consumed was about 1,300 to 1,400 kcal / kg · clinker in wet rotary kilns in the past, but in the current NSP kiln, heat is released by drying the raw materials and calcining limestone. The unit is being lowered to about 700kcal / kgclinker.

Table 1 Heat Balance of Portland Cement Clinker Formation Reaction

The present invention has been made to solve the above problems of the prior art, the problem of the prior art with respect to the production of the above-mentioned portland cement, namely the use of natural resources according to the use of enormous amounts of limestone, clay, silica, iron oxide, etc. Depletion and deterioration of nature, generation of CO ₂ (g) due to calcination of limestone, and the enormous amount of energy used in cement manufacturing processes such as raw material process, firing process, and grinding process, and thus CO ₂ (g) In order to improve the production of molten iron, by using the components and heat of the hot molten blast furnace slag generated as a by-product from the blast furnace in the production of portland cement, the raw material supply cost and energy cost of the Portland cement manufacturing process are reduced. Portland cement manufacturing method using molten blast furnace slag to find a solution and Portland cement manufactured therefrom Its purpose is to.

In particular, the manufacturing method of portland cement using molten blast furnace slag to reduce the generation of CO ₂ (g), which is currently considered as one of the biggest factors of global warming, through the reduction of limestone consumption, energy consumption reduction, recovery and recycling. And it is an object to provide a portland cement manufactured through this.

In order to achieve the above object, the present invention, the molten blast furnace slag discharged in the process of manufacturing molten iron in the blast furnace (blast furnace) of the steel manufacturing process, and the feed material of Ca and Fe blended so that the saturation degree 78 ~ 100 A compounding step; A clinker acquisition step of taking a cement clinker by injecting a compound that has undergone the blending step into a reactor and reacting at a temperature of 1,400 ° C. or more for 5 to 60 minutes; Characterized in that it comprises a crushing step of crushing and pulverizing by adding one or more of the phosphate gypsum, titanium gypsum, desulfurized gypsum, natural gypsum to the cement clinker obtained through the clinker acquisition step.

Ca feed material of the Ca and Fe feed material is limestone, waste lime or cement kiln dust, Fe feed material is steel slag, electric furnace slag or iron ore, the high temperature cement obtained between the clinker acquisition step and crushing step It is characterized in that it further comprises a sensible heat recovery step of cooling the clinker through the sensible heat recovery.

In the clinker acquisition step, the hot gas discharged when the compound is reacted in the reactor capable of self-heating is supplied to a gas heater, and the hot air further heated by the gas heater prevents preheating of the Ca and Fe feed materials. Used to reduce the self-heating load of the reactor, wherein the gas heater heats the outside air to supply the reactor when the reactor is not heated and only the hot air when the reactor is heated. It is characterized in that the mixture is bubbling by feeding to the reactor, wherein the hot gas is supplied to the heat accumulator and the heat energy stored in the heat accumulator is used in the steel manufacturing process.

On the other hand, the hot gas discharged when the compound is reacted in the reactor in the clinker acquisition step is supplied to a preheating furnace into which the Ca and Fe feed materials are fed, and thus the preheated Ca and Fe feed materials are supplied to the reactor. And the exhaust gas discharged from the preheating furnace is reheated to a higher temperature through a gas heater to be introduced into a lower portion of the reactor, wherein the gas heater heats external air when the reactor is not heated to the reactor. It is characterized in that for supplying to the reactor and when the reactor is heated to supply only the exhaust gas to the reactor so that the compound is bubbled, the exhaust gas is supplied to the heat accumulator and the heat energy stored in the heat accumulator is used in the steel manufacturing process It features.

In addition, the sensible heat recovered through the sensible heat recovery unit is supplied to the heat storage unit and the heat energy stored in the heat storage unit is used in the steel manufacturing process.

As described above, the Portland cement manufacturing method using the molten blast furnace slag according to the present invention and the Portland cement produced through the high heat content of the molten hot blast furnace slag of 1,400 ℃ or more generated as a by-product when producing molten iron for steelmaking ( 455 kcal / kg) and its components to reduce raw materials, such as limestone, silica, clay and iron ore, natural resources compared to conventional portland cement, and their crushing and drying, heating, dehydration, pyrolysis and decomposition products of limestone To reduce the energy required for heating.

In addition, the reduction of the amount of CO ₂ (g) which is a greenhouse gas caused by the reduction of the use of natural resources limestone and energy and the reduction of energy by recovering the heat contained in cooling the molten Portland cement clinker and recycling it in the steel process It can be expected to have various effects, such as the reduction of energy costs, the suppression of CO ₂ (g) generation, and the reduction of the amount of calcareous raw materials, due to the use of thermal energy contained in molten blast furnace slag, compared to the conventional Portland cement manufacturing process. Various effects can be achieved, including the reduction of CO ₂ (g), a gas, the supply and demand for manufacturing raw materials, and the cost of crushing raw materials.

Hereinafter, with reference to the drawings will be described a portland cement manufacturing method using the blast furnace slag according to the present invention and the portland cement produced through this.

1 is a process chart showing a portland cement manufacturing method using a molten blast furnace slag according to the first embodiment of the present invention, Figure 2 is a portland cement manufacturing method using a molten blast furnace slag according to a second embodiment of the present invention One process chart.

Portland cement manufacturing method using molten blast furnace slag according to the present invention is basically the blast furnace slag of the molten state discharged during the manufacturing of molten iron in the blast furnace (blast furnace) of the steel manufacturing process, and the supply material of Ca and Fe lime saturation degree 78 To a clinker obtaining step of mixing the compounding step to obtain a cement clinker by incorporating the compounding step, the compound having undergone the compounding step into the reactor and reacting at a temperature of 1,400 ° C. or more for 5 minutes or more, and the cement clinker obtained through the clinker obtaining step. It consists of a crushing step of crushing and pulverizing by adding at least one of phosphate, titanium, desulfurized gypsum, natural gypsum, and between the clinker acquisition step and the crushing step through the sensible heat recovery unit A sensible heat recovery step of cooling is further included.

In general, Portland cement is manufactured by grinding limestone, clay, silica, iron ore, and then pulverizing mixed raw minerals in the rotary kiln at the maximum temperature of 1,450 ℃ to produce clinker minerals, and then grinding by adding gypsum as a coagulant retardant. do.

At this time, the heat source unit input to the firing process of the Portland cement clinker manufacturing process requires about 700 kcal / kg clinker per kg of clinker, and this heat source unit accounts for about 70% of the cost of manufacturing Portland cement. In addition, a large amount of limestone, clay, silica, iron ore, which are used as raw materials for portland cement manufacturing, are inherently obtained from nature, and thus consume natural resources and destroy the environment. Energy is consumed, and large amounts of greenhouse gas CO ₂ (g) are inevitably generated due to calcination of limestone and energy use.

However, the present invention is a Ca component (lime raw material) feed material lacking in molten blast furnace slag of 1,400 ℃ or more generated in the manufacturing of molten iron in the blast furnace, such as limestone, waste lime, cement kiln dust and Fe (iron raw material) feed steelmaking slag, electric furnace further added to the slag, iron ore, etc., and energy for the Portland cement clinker minerals synthesized by reacting for 5 to 60 minutes while utilizing the molten slag sensible heat and the external supply of energy remains above 1,400 ℃ temperature of C ₃ S, C ₂ After synthesizing the main minerals of Portland cement clinker such as S, C ₃ A and C ₄ AF, the sensible heat recovered when cooling the clinker is recycled to steel process such as iron ore drying and phosphate gypsum is transferred to the cooled Portland cement clinker. It consists of a process of crushing by adding at least one gypsum (CaSO ₄ · 2H ₂ O) selected from titanium gypsum, desulfurized gypsum, natural gypsum, etc. All.

The amount of slag generated in 2006 in the steel industry is shown in Table 2. As shown in Table 2, about 20 million tons of slag was generated annually, among which blast furnace slag generated about 9 million tons per year and steelmaking slag generated about 6 million tons.

Table 3 shows the chemical composition of the slag of the steel industry, and consists of CaO, SiO ₂ , Al ₂ O ₃ , Fe ₂ O _3, etc., which are the main components of the Portland cement clinker mineral.

The amount of these four components is about 89% in the case of blast furnace slag, and steelmaking slag is 71-91%, although it varies slightly depending on the steel manufacturing process.

(Table 2) Generation of Slag in the Steel Industry (2006)

(Table 3) Chemical composition of steel industry slag

In addition, blast furnace slag exists in a highly reactive amorphous form, and in the case of converter slag, it is a mineral phase such as Metal Fe, FeO, 2CaO · Fe ₂ O ₃ , 3CaO · SiO ₂ , 2CaOSiO ₂ , CaO, present in Metal Fe, Wustite (FeO), Magnetite (Fe 3 O 4) Gehlenite (2CaO · Al 2 O 3 · SiO 2) Monticellite (CaO · MgO · SiO 2) or the like.

Referring to Table 3, the alumina component for making the optimum Portland cement clinker compound in the blast furnace slag was found to be large, but the calcium oxide and iron oxide components were found to be somewhat insufficient. However, steel slag that is recovered from existing iron and recycled as aggregate is composed of a large amount of remaining iron oxide component and cement clinker compound, so it can be used as a source of Ca and Si components as well as iron source lacking in blast furnace slag. Therefore, using a relatively small amount of limestone and steelmaking slag as a by-product of the steelmaking process makes it possible to produce Portland cement clinker sufficiently.

Since 1 ton blast furnace slag can produce about 1.56 tons of Portland cement clinker, it is possible to produce about 15 million tons of Portland cement with 9 million tons of blast furnace slag generated in the domestic steel industry. This amount can replace 30% of the annual production of about 50 million tons of domestic cement.

Therefore, if the production and production of Portland cement through the present invention will be able to significantly reduce the various problems that occur in the cement company, that is, the use of large amounts of natural resources and energy and the generation of CO ₂ (g).

Referring to Figure 1 portland cement manufacturing process according to a first embodiment of the present invention will be described, the cement clinker compound using a raw material or industrial by-products containing Ca and Fe components in the molten blast furnace slag generated in the blast furnace After mixing so as to generate the component ratio, the Portland cement clinker is manufactured in a reactor (1-1) capable of using self-heating or externally supplied thermal energy for the clinker reaction, and recovers the sensible heat generated at this time for use in the steelmaking process. In the clinker acquisition step, the hot gas discharged when the mixture of molten blast furnace slag and Ca and Fe feed material is reacted in the reactor 1-1 is supplied to the self-heating gas heater 3 and the gas heater 3 Hot air further heated by) is used to preheat Ca and Fe feedstock or to reduce the self-heating load of reactor (1-1). The hot gas is supplied to the heat storage unit 4 and the thermal energy stored in the heat storage unit 4 is reused in the steel manufacturing process. In addition, the sensible heat recovered through the sensible heat recovery unit 2 is supplied to the heat storage unit 4 and the thermal energy stored in the heat storage unit 4 is also used in the steel manufacturing process. In other words, the molten blast furnace slag generated in the blast furnace is introduced into a self-heating reactor (1-1) together with raw materials or industrial by-products containing Ca and Fe components, and homogeneous mixing of the compound in the reactor (1-1) and this In order to recycle the heat generated from the reactor, the hot gas generated in the reactor 1-1 is collected and flowed back into the reactor 1-1 to bubbling the reactants, that is, the compound in the reactor 1-1. In this case, the heating gas is additionally heated by using the gas heater 3 to maintain the temperature of the air introduced into the reactor 1-1 at a higher temperature, thereby causing the self-heating load of the reactor 1-1. May be reduced. As another method for reducing the exothermic load of the reactor 1-1, Ca and Fe-containing raw materials are connected to the hot gas added from the gas heater 3 to preheat the raw materials, and then the preheated raw materials and gases are transferred to the reactor. It is also possible to add a mixture at the same time (A). In addition, at the beginning of the process, the external air is supplied to the gas heater (3), heated, and then introduced into the reactor (1-1). The hot air that has been cooled and recovered through the sensible heat recovery unit 2 is supplied to the heat storage unit 4 to be regenerated and recycled to the steel process. By crushing the cooled Portland cement clinker and adding gypsum thereto, it is crushed. Finally it becomes Portland cement. In the Portland cement manufacturing process of the present invention, when the process is operated in the Steady State, the gas is introduced into the reactor 1-1 through the gas heater 3 for the flow of material in the hot gas generated from the reactor 1-1. The remaining excess gas (excess gas obtained by the decarbonation reaction of the calcined raw material, etc.) is transferred to the heat storage unit 4 and recycled in the steel process.

On the other hand, referring to Figure 2 portland cement manufacturing process according to a second embodiment of the present invention, pre-heating the raw materials or industrial by-products containing the added Ca and Fe components with sensible heat recovered in the process and generated The exhaust gas is heated to a high temperature to be introduced into the molten blast furnace slag clinker reactor to maintain the reaction temperature in the reactor 1-2 and to mix the input raw materials uniformly. In the clinker acquisition step, the compound is mixed in the reactor 1-2. The hot gas discharged during the reaction is supplied to the preheating furnace 5 into which the Ca and Fe feed materials are added, and the exhaust gas discharged to the preheating furnace 5 is fed into the reactor and the preheated Ca and Fe feed materials are supplied to the reactor. Reheated to a higher temperature via a gas heater (3) for heating the air and introduced into the lower part of the reactor (1-2), the exhaust gas is supplied to the heat storage unit (4) and stored in this heat storage unit (4) The thermal energy is reused in the steel making process. In addition, the sensible heat recovered through the sensible heat recovery unit 2 is supplied to the heat storage unit 4, the thermal energy stored in the heat storage unit 4 is used in the steel manufacturing process. In other words, the molten blast furnace slag generated in the blast furnace is introduced into the reactor (1-2) and the raw material or industrial by-products containing Ca and Fe components preheated to high temperature through the raw material preheating furnace (5). ), And at this time, the hot gas generated from the reactor (1-2) is introduced into the raw material preheating furnace (5), and the flue gas generated during the raw material preheating is collected, and some of them are more than that of the gas heater (3). By reheating to a high temperature, the reactor is introduced from the lower part into the reactor 1-2, and the mixtures are uniformly mixed by bubbling and flowing the reactants inside the reactor as described above, and the temperature inside the reactor 1-2 is adjusted to an appropriate reaction temperature. Will be maintained. In addition, in the initial process start step, the external air is supplied to the gas heater (3), heated and then introduced into the reactor (1-2). The Portland cement clinker in which the reaction was completed in the reactor (1-2) was quenched through the sensible heat recovery unit (2), and the high temperature sensible heat recovered through the sensible heat recovery unit (2) was supplied to the heat storage unit (4) and regenerated. Is recycled to the steel process. The quenched Portland cement clinker is crushed and crushed with the addition of gypsum to finally become Portland cement. According to the Portland cement manufacturing process according to the present invention, a part of the hot exhaust gas generated from the raw material preheating furnace 5 is reheated in the gas heater 3 for the flow of the material, and is introduced into the reactor 1-2, and the remaining excess gas is supplied to the reactor 1-2. Gas (excess gas obtained by decarbonation reaction of the calcined raw material, etc.) is transferred to the heat storage unit 4 and recycled to the steel process. In the Portland cement manufacturing process of the present invention, a raw material preheated to a high temperature and a high temperature gas may be added to the reactor 1-2 in a mixed state (B).

Hereinafter, the present invention will be described in more detail with reference to the following examples.

Portland cement component minerals (C ₃ S, C ₂ S, C ₃ A, C ₄ ) are reacted at high temperature by the main raw materials (CaO, SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ ) of Portland cement clinker Design and mix Modulus (LSF, SM, IM) values according to the type and grade of raw materials to produce AF).

Here, LSF (Lime Saturation Factor) shows the reactivity of CaO component with SiO ₂ , Al ₂ O ₃ and Fe ₂ O ₃ component, and SM (Silica Modulus, silicic acid rate) shows that SiO ₂ component is Al ₂ Reactivity with O ₃ and Fe ₂ O ₃ components, IM (Iron Modulus, iron ratio) is a criterion that represents the melt phase characteristics as the ratio of the Al ₂ O ₃ component and Fe ₂ O ₃ component.

Figure 3 is a graph showing the raw material mixture ratio of blast furnace slag and limestone according to the change of lime saturation (LSF) in the two-component raw material of blast furnace slag and limestone having the chemical composition as shown in Table 1.

4 is a graph showing the change of C ₃ S and C ₂ S mineral content according to the change of lime saturation (LSF) in the two-component raw material of blast furnace slag and limestone.

Referring to Figures 3 and 4, the value of lime saturation is in the range of 78 ~ 100 blast furnace slag 47 ~ 35%, limestone can be blended raw materials in the range of 53 ~ 65%, within this range Portland cement The content of calcium silicate minerals (C ₃ S and C ₂ S), which are the main constituent minerals of the clinker, can be adjusted, and the value of the degree of lime saturation is 84 to 96.

If the value of lime saturation is less than 84, the C ₃ S content is less than 22% level, the C ₂ S content is increased to 49% level, the initial strength expression may be delayed, and conversely, Exceeding 96 increases the C ₃ S content by more than 55%, leading to a decrease in plasticity of the Portland cement clinker.

On the other hand the two-component material of blast furnace slag and limestone, alumina of blast furnace slag (Al ₂ O ₃₎ because the components are increased to rise the C ₃ A content of Portland cement clinker, part of the gap to be (C ₃ A and C ₄ AF) adjusting the content In order to do so, the use of iron raw materials is required.

5 is a graph showing the change of C ₃ A and C ₄ AF mineral content according to the content of steelmaking slag when the value of saturation degree of 94 in the three-component raw material using steelmaking slag as blast furnace slag, limestone and iron raw material.

5, the range of the content of steelmaking slag is preferably 5 to 20% in order to smooth the clinker reaction in the melt phase of the Portland cement clinker.

If the steel slag content is less than 5%, the C ₃ A content is increased to 16% or more, and the viscosity of the melt increases, whereas if it exceeds 20%, the C ₄ AF content is 26% or more and the C ₃ A content is 5%. Less than% will increase the melt content and delay the development of initial strength of Portland cement.

(Example 1)

The raw material mixture was designed to have a lime saturation value of 88.0 in the two-component raw material of blast furnace slag and limestone.

The molten blast furnace slag was changed from 1,300 ° C. to 1,450 ° C. at 50 ° C., and then limestone was added to the molten blast furnace slag, followed by reacting while maintaining the melting temperature for 5 to 60 minutes.

FIG. 6 is an X-ray diffractogram of the Portland cement clinker produced by melting at 1,300, 1,350, 1,400 and 1,450 ° C. by the reaction.

Even at 1,300 ℃, C ₃ S, C ₂ S, C ₃ A and C ₄ AF, which are the main minerals of the main Portland cement clinker, were produced, but unreacted CaO (Free-CaO) remained due to the low firing temperature.

However, non-reacted, depending on the temperature of the melt is increased to more than 1,400 ℃ CaO FIG C ₂ S reacts with the main mineral of a typical Portland cement clinker forms a _{C 3 S C 3 S, C} 2 S, C 3 A, C 4 It appeared only with AF and the like.

7 is a result of quantitative analysis of the mineral content of the Portland cement clinker synthesized in the reactor at 1,450 ℃ of the raw material mixture and reaction conditions as shown in FIG.

As a result of quantitative analysis of the constituent minerals of the Portland cement clinker as shown in Figure 7, C ₃ S: 38.5%, C ₂ S: 40.0%, C ₃ A: 14.6%, C ₄ AF: 0.3%, MgO (Periclase): The composition ratio of C ₃ S and C ₂ S showed that the composition ratio of Portland cement clinker was similar to that of the four cements. However, the content of C ₃ A was rather high and the content of C ₄ AF was very small.

(Example 2)

In the same manner as in Example 1, in the two-component raw material of molten blast furnace slag and limestone, the composition was designed so that the values of lime saturation were 92.0, 94.0, and 96.0, respectively, and then the blast furnace slag was put into a carbon container and melted at 1,450 ° C. in the melting furnace. After the blast furnace slag was prepared, limestone was added to the molten blast furnace slag and reacted while maintaining the melting temperature for 5 to 60 minutes, followed by quenching in air.

8 is an X-ray diffractogram of a Portland cement clinker produced by mixing raw materials with lime saturation values of 92.0, 94.0 and 96.0 by melting at 1,450 ° C. by the above reaction.

In Figure 8 it can be seen that the main components of Portland cement clinker (C ₃ S, C ₂ S, C ₃ A, C ₄ AF) is well developed, the calcium silicate minerals (C ₃ S and C) produced at this time ₂ S) content was 73%, and interstitial minerals (C ₃ A and C ₄ AF) were 22%.

(Example 3)

In the same manner as in Example 1, the mixing amount of steelmaking slag in the three-component raw material of molten blast furnace slag, limestone and steelmaking slag was fixed at 5.0% and 15.0%, respectively, and the mixing design was made so that the value of lime saturation was 94.0. Was added to a carbon container, made of blast furnace slag melted at 1,450 ° C. in a melting furnace, and then added limestone and steelmaking slag to the molten blast furnace slag and reacted while maintaining the melting temperature for 5 to 60 minutes, followed by quenching in air.

9 and 10 show the results of quantitative analysis of the constituent mineral content of the Portland cement clinker produced under the raw material blending and melting conditions when the blending amount of steelmaking slag was 5.0% and 15.0%, respectively, by the above reaction.

As a result of quantitative analysis of the constituent minerals of the Portland cement clinker by Q-XRD as shown in FIGS. 9 and 10, when 5.0% of steelmaking slag was mixed, C ₃ S: 55.0%, C ₂ S: 20.8%, and C ₃ A: 7.3 %, C ₄ AF: 8.7%, 15.0% of steelmaking slag C ₃ S: 53.5%, C ₂ S: 24.9%, C ₃ A: 1.4%, C ₄ AF: 12.5% It shows the composition ratio of typical ordinary Portland cement clinker compound.

1 is a process chart showing a portland cement manufacturing method using a molten blast furnace slag according to a first embodiment of the present invention.

Figure 2 is a process diagram showing a portland cement manufacturing method using a molten blast furnace slag according to a second embodiment of the present invention.

Figure 3 is a graph showing the raw material mixture ratio of blast furnace slag and limestone according to the change of lime saturation (LSF) in the two-component raw material of blast furnace slag and limestone according to the present invention.

Figure 4 is a graph showing the change of C ₃ S and C ₂ S mineral content according to the lime saturation (LSF) change in the two-component raw material of blast furnace slag and limestone according to the present invention.

Figure 5 is a graph showing the change of C ₃ A and C ₄ AF mineral content according to the content of steelmaking slag when the value of saturation degree of 94 in the three-component raw material using the steelmaking slag as blast furnace slag, limestone and iron raw material according to the present invention Degree.

6 is an X-ray diffractogram of a Portland cement clinker produced by melting at 1,300, 1,350, 1,400 and 1,450 ° C. in accordance with the present invention.

Figure 7 is the result of quantitative analysis of the mineral content of the Portland cement clinker synthesized in the melting furnace of 1,450 ℃ of the raw material mixture and reaction conditions according to the present invention.

8 is an X-ray diffraction diagram of the Portland cement clinker produced by melting at 1,450 ° C. by mixing raw materials with lime saturation values of 92.0, 94.0 and 96.0, respectively.

Figure 9 is the result of quantitative analysis of the constituent minerals of Portland cement clinker in the case of mixing 5.0% raw steel slag according to the present invention by Q-XRD.

10 is a result of quantitative analysis of the constituent minerals of Portland cement clinker in the case of mixing 15.0% of steelmaking slag according to the present invention with Q-XRD.

Claims (9)

delete delete A blending step of blending the molten blast furnace slag discharged in the process of manufacturing molten iron in a blast furnace (blast furnace) and a feed material of Ca and Fe so as to have a saturation degree of 78 to 100; A clinker acquisition step of taking a cement clinker by injecting a compound that has undergone the blending step into a reactor (1-1, 1-2) for 5 to 60 minutes at a temperature of 1,400 ° C. or more; Consists of crushing and grinding by adding one or more of phosphate, gypsum, titanium gypsum, desulfurized gypsum, natural gypsum to the cement clinker obtained through the clinker acquisition step; Ca feed material of the Ca and Fe feed material is limestone, waste lime or cement kiln dust, Fe feed material is steel slag, electric furnace slag or iron ore, Between the clinker acquisition step and crushing step Portland cement manufacturing method using a molten blast furnace slag characterized in that it further comprises a sensible heat recovery step of cooling the obtained high temperature cement clinker through the sensible heat recovery unit (2). The method of claim 3, The hot gas discharged when the compound is reacted in the reactor 1-1 capable of self-heating in the clinker acquiring step is supplied to the gas heater 3, and the hot air further heated by the gas heater 3. Is used to preheat the feed of Ca and Fe or to reduce the self-heating load of the reactor (1-1), the gas heater (3) when the reactor (1-1) is not heated The outside air is heated to the reactor 1-1, and when the reactor 1-1 is heated, only the hot air passing through the gas heater 3 is supplied to the reactor 1-1. Portland cement manufacturing method using a blast furnace slag characterized in that the compound is bubbling (bubbling). The method of claim 3, In the clinker acquisition step, the hot gas discharged when the compound is reacted in the reactor (1-2) is supplied to a preheating furnace into which the Ca and Fe feed material is added, thereby preheating the Ca and Fe feed material. The exhaust gas discharged from the preheating furnace (5) is reheated to a higher temperature through the gas heater (3) and introduced into the lower portion of the reactor (1-2). The gas heater 3 heats external air to supply the reactor 1-2 when the reactor 1-2 is not heated, and only exhaust gas when the reactor 1-2 is heated. Method for producing a portland cement using a molten blast furnace slag characterized in that the feed to the reactor (1-2) so that the compound is bubbled. The method according to claim 4, The hot gas is supplied to the heat accumulator (4), the thermal energy stored in the heat accumulator (4) is used in the steel manufacturing process Portland cement manufacturing method using molten blast furnace slag. The method according to claim 5, Part of the exhaust gas discharged from the preliminary heating furnace (5) is supplied to the heat storage unit (4), the heat energy stored in the heat storage unit (4) Portland cement using molten blast furnace slag, characterized in that used in the steel manufacturing process Manufacturing method. The method according to claim 6 or 7, The sensible heat recovered through the sensible heat recovery unit 2 is supplied to the heat storage unit 4 and the thermal energy stored in the heat storage unit 4 is used in the steel manufacturing process Portland cement manufacturing method using molten blast furnace slag . delete

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