TWI740176B - Manufacturing method of cement modifier and functional cement material containing the cement modifier - Google Patents

Abstract

A method for manufacturing a cement modifier, which is suitable for recycling the reduced ballast of an electric arc furnace to produce a cement modifier. The manufacturing method includes: providing the reduced ballast of the electric arc furnace; pulverizing the reduced ballast of the electric arc furnace into The first refined product with an average particle diameter of less than 20 mm; the iron content in the first crushed material is removed by a magnetic generator to obtain tailings; the tailings are further crushed into a secondary refined product with an average particle diameter of less than 5 mm ; Grind low-water content products into ^{cement modifiers with a fineness of 500 m 2} /kg or more. In addition, after mixing the cement modifier and Portland cement in a specific ratio, functional cement materials with different special properties can be obtained.

Description

Manufacturing method of cement modifier and functional cement material containing the cement modifier

The present invention relates to a resource utilization method of electric arc furnace reduction ballast, in particular to a method for manufacturing cement modifier by electric arc furnace reduction ballast and a functional cement material containing the cement modifier.

Steelmaking can be divided into blast furnace steelmaking, converter steelmaking and electric arc furnace steelmaking. The raw material for blast furnace steelmaking is iron ore. The hot air is passed through the coal by a blower to generate high temperature, and the iron content in the iron ore is extracted into iron. After the water and molten iron enter the converter, scrap iron is used as raw material to produce molten steel, which becomes steel after cooling. The converter steelmaking also uses iron ore as the raw material, while the electric arc furnace steelmaking raw material is mainly scrap iron. The electric current is passed through the graphite and scrap iron to generate an electric arc to melt the scrap iron.

Electric arc furnace steelmaking can be divided into five major stages: raw material collection, smelting pre-operation, melting period, oxidation period and reduction period. The raw material of electric arc furnace steelmaking is mainly scrap iron, which is derusted and impurity removed and is not suitable for smelting. The other metals can be used as raw materials for smelting, and then batching according to the properties of the desired steel to complete the pre-smelting operations. The raw materials are melted in the electric arc furnace through high-voltage energization to generate electric arcs, and a little slag will be produced during the melting period. In order to cover the molten steel and stabilize the arc, during the oxidation period, the ore containing high-valent iron oxide is added or pure oxygen is directly introduced. After being converted into low-valent iron oxide, the carbon and phosphorus in the molten steel will be oxidized, and oxide ballast will be generated at this time. , After removing the oxide ballast, it enters the reduction period. During the reduction period, calcium oxide (lime) is added to form thin ballast, and then carbon powder is added to perform deoxygenation and desulfurization to form reduced ballast.

The slag produced after electric arc furnace steelmaking is mainly in the oxidation period and reduction period. They are oxidized ballast and reduced ballast respectively. The shape of oxide ballast is similar to natural igneous rock. Powder. At present, the domestic electric arc furnace steelmaking plants produce about 1.2 million metric tons of oxide ballast and 400,000 metric tons of reduced ballast for every 10 million metric tons of steel produced. Oxidized ballast and reduced ballast are industrial wastes. According to the announcement of the Industrial Bureau of the Ministry of Economic Affairs, the reuse of ballast mainly includes the reuse of oxide ballast (stone): raw material for cement, raw material for asphalt concrete, and control for pipe trench backfilling. Low-strength backfill materials, raw materials for paving projects (roads, sidewalks, container yards, or parking lots) with granular materials for base or bottom gradation, raw materials for New Jersey guardrails, or ready-mixed concrete granules for non-structural objects after high-pressure steam treatment Raw materials, ready-mixed concrete raw materials for non-structural objects, aggregate raw materials for cement products or raw materials for concrete (floor) bricks, hollow bricks, cement tiles, cement slabs, curbs, concrete pipes, manholes, and trench covers; reduced ballast (stone) ) Recycling uses include cement raw materials, asphalt concrete pellet raw materials, paving engineering (roads, sidewalks, container yards or parking lots) base or bottom-level aggregate raw materials, New Jersey guardrail raw materials, or as non-productive materials after high-pressure steam treatment. Ready-mixed concrete aggregate raw materials for structures, ready-mixed concrete raw materials for non-structural objects, aggregate raw materials for cement products or concrete (floor) bricks, hollow bricks, cement tiles, cement slabs, curbs, concrete pipes, manholes, trench covers The raw materials.

In addition, among the above-mentioned applications, oxidation ballast and reduction ballast are used in paving engineering (roads, sidewalks, container yards or parking lots) for the base or bottom level granular materials, controllable low-strength backfill materials for pipe trench backfilling, etc. There are two main treatment methods. One is to treat the reduced ballast by steam curing to accelerate its stabilization or stabilization, and then use the stabilized reduced ballast as a paving project (roads, sidewalks, container yards or The base or bottom grade of the parking lot) is the raw material of granular materials; the second is to use stabilized reduction ballast and oxide ballast for non-structural materials for ready-mixed concrete or controllable low-strength backfill materials for pipe trench backfilling. However, the current reduction of ballast has yet to be handled by the operation of high-pressure health equipment.

In addition, in recent years, researches on using oxidized ballast and reduced ballast as concrete aggregates, making environmentally friendly cement, etc., and sintering flux have also emerged. For example, gypsum is added to reduced ballast and ground into cement, and then mixed with electric arc furnace air-cooled oxidation ballast (when coarse aggregate) and electric arc furnace water quenched oxidation ballast (when fine aggregate) is mixed to make U-shaped Cement building materials such as trenches, slabs, stones, culvert pipes, quay walls, cement bricks, landscape materials, wave-eliminating blocks and artificial reefs.

Secondly, some technical studies have found that the reduction ballast has a good activity index and can improve the setting time of the cement paste. Therefore, it is recommended to use electric arc furnace ballast as a material to improve the compressive strength and shrinkage of the paste, and Reduce the amount of cement to achieve the goal of recycling.

In addition, academic reports pointed out that since the main component of reduced ballast is CaO, it can act as an alkali activator in cement and has the potential to replace limestone minerals in cement raw materials. For example, research has found that 10% of the reduced ballast from electric arc furnace steelmaking slag can replace part of the cement to mix concrete. The 28-day compressive strength meets the design strength requirements and can help improve its durability. Studies have also pointed out that 15% of the reduced ballast of electric arc furnace steelmaking slag can replace part of the cement without reducing its compressive strength.

In addition, studies have also pointed out that a mixture of electric arc furnace steelmaking ballast and gas converter ballast can be added to the cement raw materials in an appropriate proportion to modify the cement. For example, 77% limestone sludge, 19.51% stone sludge, 2.49% coal ash sludge mixture and 1% reduced ballast are sintered at a temperature of 1,400 ℃, and after holding the temperature for 2 hours, the fully-resourced environmentally friendly cement produced The CNS 61 gas transmission type IIIA cement specification value has the potential to be used as an emergency repair engineering material.

In addition, the Republic of China Patent No. I448556 discloses a pre-treatment method for electric arc furnace slag recycling, which includes providing an electric arc furnace slag containing reduced ballast, containing 15wt% to 30wt% of reduced ballast; performing a screening In the process, the electric arc furnace ballast containing reduced ballast is divided into a coarse material part and a fine material part; a crushing and washing process is carried out, and the coarse material part is washed into a fine particle part and a bottom mud Then, the bottom mud part is ground to form a reduced ballast powder, and a powder selection process is performed to select the reduced ballast powder that can be used in concrete instead of cement. However, the Republic of China Patent No. I448556 is at best a pretreatment method for electric arc furnace ballast recycling, and can only obtain reduced ballast fine powder ^{with a specific surface area of 300m 2} /kg to 500m ^{2 /kg.}

Therefore, it can be understood that there have been some preliminary academic research results on the use of reduced ballast to replace part of the cement raw materials, but there is still no appropriate resource treatment method for reduced ballast. The content of cement modifiers that are added to replace cement raw materials has not produced a high-performance cement that has been modified by adding the cement, and their manufacturing methods.

In view of this, the inventors of the present invention devote themselves to researching excellent methods and good countermeasures to solve the above-mentioned problems, and then research and develop methods that can recycle or recycle the reduced ballast. That is, the object of the present invention is to provide a method for producing a cement modifier and a cement modifier produced by the method. This manufacturing method is mainly to pulverize the reduction ballast of the electric arc furnace twice to form a pulverized material with a particle size of less than 5 mm, and then grind the pulverized material into ^{a cement modification with a fineness of more than 500m 2} /kg by the grinding process. Quality agent.

Furthermore, mixing the cement modifier and portland cement can not only replace part of the cement, but also obtain a functional cement material that can improve the time required for cement setting and the cementing activity. The functional cement material of the present invention is of special functionality, added in a small amount to cement, has permeability resistance, abrasion resistance, radiation resistance, low heat of hydration, corrosion resistance, expansion and contraction resistance, abrasion resistance, frost resistance, carbonization resistance, etc. Performance, if it is added more than 1:1, it can be used for a controlled low strength material (CLSM) cement material. It not only has high fluidity and low compressive strength, but also is very conducive to the need for repeated opening. The backfill material of the pipe trench project during excavation can therefore be used as a cement material for frequent construction areas.

Furthermore, in an embodiment of the present invention, the method for manufacturing the cement modifier preferably includes the following steps: a raw material crushing process, which at least includes a first crushing step of crushing the raw materials to obtain a first refined product; the raw material It belongs to steel ballast, which includes at least reduction ballast from an electric arc furnace; an iron separation process, which is at least equipped with a first magnetic separation step using magnetic force to tailings; the magnetic force comes from a magnetic force generating device; a secondary refinement process, which In order to have at least the secondary pulverization step of further pulverizing the tailings to obtain a secondary refined product, and for the secondary refined product, it can achieve a low-water content product with a moisture content of less than 5% (the pretreatment process can be Reduce moisture); The fine powdering process, which at least has the step of further finely grinding the low-water content product to obtain a cement modifier. In addition, the “tailings” referred to in the present invention refers to the low-iron content material left after the iron-containing components are removed from the first refined product of the reduced ballast.

Secondly, according to the technical idea of the present invention, the average particle size of the first refined product is less than 20 mm, and the average particle size of the second refined product is less than 5 mm. In addition, the cement modifier of the present invention has a fineness (specific surface area) of 500 m ² /kg or more as measured by the air permeability method, preferably the fineness of the cement modifier as measured by the air permeability method (Specific surface area) is 1000 m ² /kg or more; the better one is that the fineness (specific surface area) of the cement modifier measured by the air permeability method is less than 1500 m ² /kg, and the best one is the cement modification The fineness (specific surface area) of the quality agent is 1000 m ² /kg ~1500 m ² /kg.

In addition, the cement modifier of the present invention contains substances such as silica, alumina, iron oxide, calcium oxide, etc., and can be used as a material for the Bu Zuolan reaction. For example, in an embodiment of the present invention, the calcium oxide content in the cement modifier is 55% to 57%, the aluminum oxide content is 10.7% to 11.1%, and the silicon dioxide content is 16% to 18%. , Magnesium oxide content is 8%-9%.

In another embodiment of the present invention, the calcium oxide content of the cement modifier is 55%~57%, the aluminum oxide content is 10.7%~11.1%, the silicon dioxide content is 16%~18%, and the oxidation The magnesium content is 8%-9%.

In another embodiment of the present invention, the lower limit of alkalinity of the cement modifier of the present invention is preferably 1.5 or more, and the lower limit of alkalinity of the cement modifier is more preferably 1.6 or more. The best lower limit of the alkalinity of the agent is 1.8 or more. Furthermore, the upper limit of the alkalinity of the cement modifier of the present invention is preferably 3.5 or less, the upper limit of the alkalinity of the cement modifier is more preferably 3.4 or less, and the upper limit of the alkalinity of the cement modifier is the best Those are less than 3.3. In addition, the ideal alkalinity of the cement modifier is in the range of 1.5 to 3.5. Moreover, the alkalinity refers to the ratio of the calcium oxide content (CaO%) in the cement modifier to the sum of the silica content (SiO ₂ %) and the phosphorus pentoxide content (P ₂ O ₅ %): Alk = (CaO%) / [(SiO ₂ %) + (P ₂ O ₅ %)].

In another embodiment of the present invention, the _{content of dicalcium silicate (C 2} S) of the cement modifier is 30%-40%, and _{the content of tricalcium silicate (C 3} S) is 11%-14% , The content of tricalcium aluminate (C ₃ A) is 26%~27%.

In other embodiments of the present invention, the grinding process is performed by a roller type vertical milling device.

In addition, another object of the present invention is to provide a functional cement material, which is obtained by uniformly mixing the above-mentioned cement modifier and Portland cement at a specific mixing ratio; wherein the furnace in the Portland cement The total content of stone, fly ash and lime is less than 5%, and the blending ratio of the cement modifier and the portland cement is in the range of 1:10-10:1. In addition, according to the technical idea of the present invention, the blending ratio of the cement modifier and the Portland cement is preferably in the range of 1:8 to 8:1; more preferably in the range of 1:5 to 5:1 ; The best is in the range of 1:4~3:5.

In addition, in another embodiment of the present invention, the activity coefficient of the functional cement material is higher than 75% on the 28th day.

Hereinafter, various specific embodiments are listed and explained in more detail in order to make the spirit and content of the present invention more complete and easy to understand; however, those with ordinary knowledge in this art should It is understood that the present invention is of course not limited to these examples, and other same or equal functions and sequence of steps can also be used to achieve the present invention.

In this article, the scientific and technical terms used here have the same meanings as understood and used by those with ordinary knowledge in the technical field to which the present invention belongs. In addition, without conflict with the context, the singular nouns used in this specification cover the plural nouns; and the plural nouns used also cover the singular nouns.

In this article, the numerical values and parameters used to define the scope of the present invention inevitably contain standard deviations due to individual test methods, so they are mostly expressed as approximate quantitative values. However, in specific embodiments, Relevant values presented as accurately as possible. In this context, "about" generally depends on the considerations of those with ordinary knowledge in the technical field to which the present invention belongs, and generally means that the actual value falls within the acceptable standard error of the average value. For example, the actual value is within an acceptable standard error of the average value. Within ±10%, ±5%, ±1%, or ±0.5% of a specific value or range.

Please refer to FIG. 1 and FIG. 2, which are a standard flow chart and a schematic diagram of the manufacturing system architecture of the manufacturing method of the cement modifier of the present invention. The manufacturing method of the cement modifier of the present invention is to pulverize the reduced ballast of the electric arc furnace, usually after two pulverization processes, and then further pulverized by a grinding equipment to obtain the cement modifier. The specific manufacturing steps generally include: a raw material crushing process S1, an iron separation process S2, a secondary refinement process S3, and a micronization process S4.

More specifically, first, the raw material crushing process S1 is described. According to the technical idea of the present invention, in the raw material crushing process S1, the reduced ballast Sb from the electric arc furnace is transported to a first crushing unit 10 for crushing, and the crushed particles are sieved by a sieving machine with a mesh size of less than 20 mm. Finally, coarse particles with an average particle size greater than 20 mm and fine particles with an average particle size of less than 20 mm are obtained, and fine particles with an average particle size of less than 20 mm are taken as the first refined product Sc. In an embodiment of the present invention, the first crushing unit 10 may be a jaw crusher, a rod mill or a cone crusher for coarse crushing.

Next, the iron separation process S2 will be described. According to the technical idea of the present invention, in the iron separation process S2, the first refined product Sc is passed through a magnetic separation unit 20 to separate the iron-containing substance F in the first refined product Sc to remove the first refined product The iron-containing substance F in Sc is obtained tailings Sd, and then enters the secondary refinement process S3. Furthermore, in an embodiment of the present invention, the magnetic separation unit 20 may be a magnetic force generating device, such as a cylindrical magnetic separator or a plane conveying magnetic separator.

Next, the second refinement process S3 is explained. According to the technical idea of the present invention, in the secondary refinement process S3, the tailings Sd is transported to the second crushing unit 30 for the secondary refinement process, that is, the process of re-pulverization is performed, and the crushed particles are smaller than the mesh size. Sieved by a 5 mm sieving machine, and finally obtained coarse particles with an average particle size greater than 5 mm and fine particles with an average particle size of less than 5 mm. The fine particles with an average particle size of less than 5 mm are used as the secondary refined product Sf, and then Enter the micronization process S4. In an embodiment of the present invention, the second crushing unit 30 may be a cone crusher, hammer crusher or impact crusher for ongoing crushing. In addition, after the tailings Sd undergoes the aforementioned raw material crushing process S1, iron separation process S2, and secondary refinement process S3 to form a secondary refined product Sf, its water content has been reduced to below 5%.

Then, the micronization process S4 will be described. In the micronizing process S4, the secondary refined product Sf is transported to a grinding unit 50 for grinding, so that it becomes a cement modifier Sg with ^{a fineness of 1000 m 2} /kg to 1500 m ^{2 /kg.} In this embodiment, the grinding unit 50 can be a roller type vertical mill device, which integrates crushing, grinding, and powder selection. It has low power consumption, good sealing performance, 30-50db lower noise than a ball mill, and can be deployed in the open air. , Small footprint, simple process, etc. The required fineness and particle size distribution can be obtained by adjusting the speed of the separator, the air flow rate of the mill and the grinding pressure, and combining with the appropriate height of the retaining ring. After meeting the fineness requirements of the grinding and reducing the iron content in the steel ballast, the advantages of the roller vertical mill device are immediately evident: its output is high, the power consumption is low, and the allowable water content can be as high as 20%, and the specific surface area of the finished product is easy. It can reach above 450～500m ² /kg, which is beneficial to the large-scale production of steel ballast powder. As shown in Figure 3, the roller type vertical mill device includes a grinding disc 51 at the bottom. A plurality of rollers 52 are arranged on the grinding disc 51. The grinding disc 51 and the rollers 52 can rotate relatively. The grinding unit 50 obtains the cement modifier Sg through the grinding of the grinding disc 51 and the roller 52, and the gas blown in from the bottom raises the cement modifier Sg and is discharged from the discharge port 54 for collection. Furthermore, according to the technical idea of the present invention, the number of rollers 52 is preferably 28 or less, and the rotation speed of the grinding disc 51 is greater than 180 rpm.

Furthermore, in another embodiment of the present invention, a secondary iron separation process may be further included between the secondary refinement process S3 and the micronization process S4, which is to re-refine the iron content in the secondary refinement Sf. The substance F is separated to ensure that the secondary refined product Sf before entering the micronization process S4 does not contain the iron substance F. Furthermore, in an embodiment of the present invention, the secondary magnetic separation unit may be a magnetic force generating device, such as a cylindrical magnetic separator or a plane conveying magnetic separator.

In an embodiment of the present invention, the cement modifier obtained by the present invention can be further uniformly mixed with Portland cement P to form a functional cement material. According to the technical idea of the present invention, the mixing ratio of the cement modifier and the Portland cement is generally in the range of 1:10-10:1; preferably in the range of 1:8-8:1; more preferably It is in the range of 1:5~5:1; the best is in the range of 1:4~3:5.

The cement modifier Sg after grinding can be used as the material for Bu Zuolan reaction. The so-called Bu Zuolan reaction refers to the cementation produced by the hydration of silica and aluminum oxide with cement, which can fill the tiny gaps in concrete, so that water in the air will not easily penetrate into the concrete materials and corrode the steel bars. The cement modifier Sg is mixed with Portland cement, which can partially replace the cement material used to produce the Portland reaction in Portland cement. In this embodiment, the content of blast furnace stone powder, fly ash and lime contained in Portland cement P may be less than 5%.

In addition, according to the "Earc Furnace Reduction Ballast Stabilization Technical Manual" published by the Industrial Bureau of the Ministry of Economic Affairs, cement modifier Sg ground to a very fine level can also produce a stabilizing effect at the same time, that is, the free oxidation in the arc furnace reduction ballast Magnesium and calcium oxide will be stable without swelling. "Examples" (Examples 1 to 4) Preparation of cement modifier

In Examples 1 to 4, the above-mentioned method for producing the cement modifier of the present invention was ground to produce cement modification through a raw material powdering process, an iron separation process, a secondary refining process, and a fine powdering process. Agent.

Specifically, in Examples 1 to 4, first, in the raw material pulverization process, a rod mill or a cone crusher was used to pulverize the reduced ballast taken from the electric arc furnace steelmaking and be separated by a sieving machine to obtain an average particle size. Coarse debris with a diameter of less than 20 mm (ie, the first refined product). Then, in the iron separation process, use magnetic separation equipment (for example, a magnetic force generator) to remove the iron-containing components in the first refined product to obtain tailings; then, the tailings are further refined in the secondary refinement process Finely pulverized and separated by a sieving machine to obtain finely divided products with an average particle diameter of less than 5 mm (ie, secondary refined products). Finally, in the fine powdering process, the low water content product obtained above is further finely ground to obtain cement modifier Sg1, cement modifier Sg2, and cement ^{with a fineness of 1000m 2} /kg ~1500m ^{2 /kg} Modifier Sg3, and cement modifier Sg4.

Next, for the cement modifier Sg1, cement modifier Sg2, cement modifier Sg3, and cement modifier Sg4 obtained in Examples 1 to 4, each fineness (ie, Specific surface area, m ² /kg), the fineness of cement modifier Sg1 is 1079m ² /kg, and the fineness of cement modifier Sg2 is 1356 m ² /kg at the minimum and 1420 m ² /kg at the maximum. The fineness of the cement modifier Sg3 was 500 m ² /kg, and the fineness of Sg4 was 800 m ² /kg, and the obtained analysis results are described in Table 1.

In addition, for the commercially available Portland cement of Comparative Example 1, the fineness (ie, specific surface area, m ² /kg) was also measured according to the air permeability method to obtain a fineness of 390 m ² /kg. The obtained analysis results are shown in Table 1.

Therefore, it can be confirmed that the fineness of the cement modifier Sg1, cement modifier Sg2, cement modifier Sg3, and cement modifier Sg4 obtained in Examples to 4 of the present invention is significantly better than that of the commercially available cement modifier Sg4 of Comparative Example 1. Portland Cement. Therefore, when the cement modifier Sg1, cement modifier Sg2, cement modifier Sg3, and cement modifier Sg4 obtained in Examples 1 to 4 of the present invention are added to commercially available cement, it can be effective Enhance the activity of performing Bu Zuolan reaction.

Then, referring to the CNS specification, the cement modifier Sg1, the cement modifier Sg2, the cement modifier Sg3, and the cement modifier Sg4 obtained in Examples 1 to 4 were subjected to silica SiO ₂ (%) , Aluminum oxide Al ₂ O ₃ (%), iron oxide Fe ₂ O ₃ (%), calcium oxide CaO (%), magnesium oxide MgO (%), sulfur trioxide SO ₃ (%), loss on ignition LOI (%), insoluble residue IR (%), sulfide S (%), titanium dioxide TiO ₂ (%), phosphorus pentoxide P ₂ O ₅ (%), sodium oxide Na ₂ O (%), potassium oxide K ₂ O (%), free calcium oxide f-CaO (%), chlorine Cl (%), alkalinity, dicalcium silicate C ₂ S (%), dicalcium aluminate C ₃ A (%), three silicate Calcium C ₃ S (%), _{tetracalcium aluminoferrite C 4} AF (%), C ₄ AF+2C ₃ A, C ₃ S+4.75C ₃ A and other component analysis, and the obtained analysis results are recorded in Table 1 . Among them, the alkalinity is defined as the ratio of the percentage of calcium oxide to the sum of the percentage of silicon dioxide and the percentage of phosphorus pentoxide, that is, alkalinity = CaO%/(SiO ₂ %+P ₂ O ₅ %) .

In addition, refer to CNS specifications for _{silicon dioxide SiO 2} (%), aluminum oxide Al ₂ O ₃ (%), iron oxide Fe ₂ O ₃ (%), calcium oxide CaO (%), magnesium oxide MgO (%) , Sulfur trioxide SO ₃ (%), loss on ignition LOI (%), insoluble residue IR (%), titanium dioxide TiO ₂ (%), phosphorus pentoxide P ₂ O ₅ (%), alkalinity, silicic acid Dicalcium C ₂ S (%), dicalcium aluminate C ₃ A (%), tricalcium silicate C ₃ S (%), tetracalcium _{aluminate ferrite C 4} AF (%) and other components are analyzed, and the obtained The results of the analysis are shown in Table 1. 【Table 1】 Comparative example 1 Example 1 Example 2 Example 3 Example 4 project Portland Cement Cement modifier Sg1 Cement modifier Sg2 Cement modifier Sg3 Cement modifier Sg4 Fineness (specific surface area) (air permeability method) (m ² /kg) 390 1079 Minimum value 1356 Maximum value 1420 500 800 Silicon dioxide SiO ₂ (%) 20.5 17.4 16.5 17.0 17.2 Aluminum oxide Al ₂ O ₃ (%) 4.6 11.1 10.7 10.8 11.0 Iron oxide Fe ₂ O ₃ (%) 3.59 1.4 3.7 1.5 2.0 Calcium oxide CaO (%) 63.1 56.5 55.8 56.0 56.2 Magnesium oxide MgO (%) 2.1 8.9 8.3 8.5 8.6 Sulfur trioxide SO ₃ (%) 2.49 0.94 1.27 1.02 1.10 Loss on ignition LOI (%) 2.0 8.3 6.9 7.2 7.4 Insoluble residue IR(%) 0.19 2.45 2.54 2,48 2.50 Sulfide S(%) - 0.47 0.33 0.40 0.38 Titanium dioxide TiO ₂ (%) 0.30 0.25 0.29 0.26 0.28 Phosphorus pentoxide P ₂ O ₅ (%) 0.09 0.03 0.05 0.03 0.04 Sodium oxide Na ₂ O (%) - 0.16 0.17 0.15 0.16 Potassium oxide K ₂ O (%) - 0.08 0.09 0.08 0.08 Free calcium oxide f-CaO(%) - 0.81 0.82 0.80 0.81 Chlorine Cl (%) - 0.007 0.066 0.008 0.007 Alkalinity 3.06 3.24 3.37 3.26 3.28 Dicalcium silicate C ₂ S(%) 15 39.1 31.4 38.0 36.4 Tricalcium aluminate C ₃ A(%) 6.1 26.9 22.0 25.0 24.2 Tricalcium silicate C ₃ S(%) 58 14.2 11.4 12.6 13.2 Tetracalcium Aluminoferrate C ₄ AF (%) 10.9 4.4 21.0 8.4 10.2 C ₄ AF+2C ₃ A - 58.2 55.3 56.2 57.2 C ₃ S+4.75C ₃ A - 142.1 125.4 136.2 130.0

It can be seen from the above Table 1 that the cement modifiers Sg1, Sg2, Sg3, and Sg4 obtained in Examples 1 to 4 of the present invention have the same properties in terms of silica, iron oxide, calcium oxide, and alkalinity. The commercially available Portland cement of Comparative Example 1 has similar content, composition, and characteristics.

In addition, in the cement modifiers Sg1, Sg2, Sg3, and Sg4 obtained in Examples 1 to 4 of the present invention, the content of aluminum oxide is 11.1%, 10.7%, 10.8%, and 11.0%, respectively, which is obviously It is higher than the commercially available Portland cement of Comparative Example 1, so it can be confirmed that the cement modifiers Sg1, Sg2, Sg3, and Sg4 of the present invention are very suitable as materials for the Portland reaction. "Liquidity Analysis"

Furthermore, as shown in Table 1 above, the content of dicalcium silicate in the cement modifiers Sg1, Sg2, Sg3, and Sg4 obtained in Examples 1 to 4 of the present invention are 39.1%, 31.4%, 38.0% and 36.4%. The content of dicalcium silicate in the commercially available Portland cement of Comparative Example 1 is 15%. Therefore, it can be confirmed that in terms of dicalcium silicate, the cement modifiers Sg1, Sg2, Sg3, and Sg4 of the present invention have a content of dicalcium silicate that is significantly higher than that of the commercially available portland cement of Comparative Example 1. Dicalcium content.

Secondly, as shown in Table 1 above, the tricalcium silicate in the cement modifiers Sg1, Sg2, Sg3, and Sg4 obtained in Examples 1 to 4 of the present invention were 14.2%, 11.4%, 12.6%, respectively. And 13.2%, while the commercial Portland cement in Comparative Example 1 has a dicalcium silicate content of 58%. Therefore, it can be confirmed that in terms of tricalcium silicate, the cement modifiers Sg1, Sg2, Sg3, and Sg4 of the present invention have a content of tricalcium silicate that is significantly lower than that of the commercially available portland cement of Comparative Example 1. Tricalcium content.

Since the hydration rate of dicalcium silicate is much slower than that of tricalcium silicate, when the content of dicalcium silicate in cement is higher, the cement can maintain better fluidity in the early stage of construction; When the content of tricalcium silicate is low, the strength of cement will decrease. "Material Activity Coefficient Analysis"

Portland cement, cement modifier Sg1, cement modifier Sg2, sand and water were mixed in the proportions shown in Table 2 to obtain concrete samples AS1, and AS2 respectively, and CNS10896 Portland cement concrete was used. The 28-day activity coefficient is obtained by sampling and inspection method of fly ash or natural Bozuolan mineral admixture. The activity coefficient is the percentage of the compressive strength ratio of the sample to the control group (pure portland cement mortar test body). When the activity coefficient is higher , Which means that the more it can accelerate the reaction of Bozuolan, accelerate the hydration of cement, and shorten the hardening time. Finally, record the results obtained in Table 2. 【Table 2】 Composition Control group (pure portland cement mortar specimen) Test group AS1 Test group AS2 Portland cement (g) 500 400 400 Cement modifier Sg1(g) 0 100 0 Cement modifier Sg2(g) 0 0 100 Sand (g) 1375 1375 1375 Water (g) 242 242 242 28-day activity coefficient (%) - 96.1 113.8

It can be seen from the results in Table 2 that when the cement modifier Sg1 and cement modifier Sg2 of the present invention are added to commercially available Portland cement, the activity indexes are 96.1% and 113.8%, respectively, which are far higher than the standard value of 75. %, which shows that by adding the cement modifier of the present invention to commercially available cement, a material that can significantly increase the activity coefficient, accelerate the progress of the Bozulan reaction, and accelerate the hydration of cement (Example 5~Example 7) Preparation of functional cement (performance test)

Next, in Example 5 to Example 7, the cement modifier Sg2 was mixed with Portland cement according to the mixing ratio shown in Table 3 to obtain functional cement materials AS3, AS4, and AS5. Among them, the content of cement modifier in functional cement material AS3 is 20%, the content of cement modifier in functional cement material AS4 is 40%, and the content of cement modifier in functional cement material AS5 is 60%.

Then, for the functional cement materials AS3, AS4, and AS5, measure various physical properties specified by CNS15286, for example, measure at least the sieve residue (%) (CNS11273) and fineness (air permeability method, m ² /kg) ( CNS2924), air content% CNS787), thermal compression expansion% (CNS1258), density (g/cm ³ ) (CNS11272), initial setting and final setting (min) (CNS786), 3 days, 7 days, 28 days of resistance Compressive strength (MPa) (CNS1010), 7 days and 28 days heat of hydration (kJ/kg) (CNS2248), 14 days, 56 days, 91 days cement mortar expansion (%) (CNS13619), etc. Then, the results are described in Table 3. 【table 3】 Pilot projects experiment method Example 5 ( AS3 ) Example 6 ( AS4 ) Example 7 (AS5) Cement modifier 20% 40% 60% Portland Cement 80% 60% 40% Sieve residue*% CNS11273 3.6 2.9 2.0 Fineness (air permeability method) (m ² /kg) CNS2924 471 560 863 Air content% CNS787 5.98 3.88 4.49 Thermal compression expansion% CNS1258 +0.07 +0.05 +0.05 Density (g/cm ³ ) CNS11272 3.06 2.98 2.82 Setting time test ( Fischer needle method ) Initial setting (min) CNS786 110 80 5 Final setting (min) 225 180 60 Compressive strength (MPa) 3 days CNS1010 23.4 1.62 1.23 7 days 33.2 16.48 10.01 28 days 40.6 26.47 19.27 Heat of Hydration (kJ/kg) 7 days CNS2248 227.7 228.5 196.8 28 days 316.6 260.2 230.6 Expansion of cement mortar (%) 14 days CNS13619 0.001 0.013 0.007 56 days 0.005 0.014 0.011 91 days 0.008 0.015 0.012 *The sieve allowance is obtained from the wet sieve test of the test sieve 0.045mm and CNS386 specification.

In addition, the standards for IS (<70), IS (70), and IP mixed cements regulated by CNS 15286 are shown in Table 4. 【Table 4】 Pilot projects experiment method CNS15286 specification (IS type/IP type) Sieve residue*% CNS11273 20.0 Fineness (air permeability method) (m ² /kg) CNS2924 - Air content% CNS787 12 Thermal compression expansion% CNS1258 0.8 Density (g/cm ³ ) CNS11272 - Setting time test ( Fischer needle method ) Initial setting (min) CNS786 ≥45 Final setting (min) ≤420 Compressive strength (MPa) 3 days CNS1010 ≥13.0 7 days ≥20.0 28 days ≥25.0 Heat of Hydration (kJ/kg) 7 days CNS2248 ≤290 28 days ≤330 Expansion of cement mortar (%) 14 days CNS13619 ≤0.020 56 days ≤0.060 91 days ≤0.050

From the data recorded in Table 3 and Table 4 above, it is clear that the compressive strength of the functional cement material AS3 of Example 5 was 23.4 Mpa and 33.2 Mpa on the 3rd, 7th, and 28th days, respectively , And 40.6 Mpa, which are in compliance with the general cement specification standard of CNS15286, and are suitable for use as cement with special functions such as hydraulic cement; the compressive strength of the functional cement material AS4 of Example 6 is on the 3rd and 7th days They are 1.62Mpa and 16.48Mpa, which are obviously lower than the general cement specification standard of CNS15286, but the compressive strength at the 28th day is 26.4Mpa, which can meet the hydraulic cement standard, so it is suitable for use as hydraulic cement; The compressive strength of the functional cement material AS5 of Example 7 was 1.23Mpa, 10.01Mpa, and 19.27Mpa on the 3rd, 7th, and 28th days, respectively, which were all slightly lower than the hydraulic cement standard of CNS15286 , But the 28th day strength is higher than 0.9 Mpa required for domestic controlled low-strength backfill materials, so it is suitable for cement materials used as controlled low-strength backfill materials.

Therefore, the cement modifier system of the present invention is very suitable for use as a functional cement material. When a small amount is added, it can exert performances such as permeability resistance, abrasion resistance, radiation resistance, low heat of hydration, corrosion resistance, expansion and contraction resistance, abrasion resistance, frost resistance, and carbonization resistance. In particular, in terms of setting time and compressive strength, the higher the amount of cement modifier added to the functional cement material, the lower the setting time and the lower the compressive strength, but it can meet this standard. High content The functional cement material of the cement modifier of the present invention is suitable for use as a controllable low-strength cement material.

Next, the functional cement materials AS30, AS4, and AS5 of Example 5 to Example 7 were measured for various constituents, for example, the maximum value of MgO%, the maximum value of SO ₃ %, the maximum value of S%, and the% of insoluble residue were measured. Maximum value, maximum ignition loss %, SiO ₂ %, Al ₂ O ₃ %, CaO%, Na ₂ O%, K ₂ O%, alkalis, (Na ₂ O%+0.658 K ₂ O%), etc., And the results are recorded in Table 5. In addition, the reference standard values for the IS (<70) type, IS (70) type, and IP type regulated by CNS 15286 are also listed in Table 5. 【table 5】 CNS 15286 Example 5 (AS3) Example 6 (AS4) Example 7 (AS5) project IS(＜70) IS(≥70) IP MgO% max - - ≤6.0 4.8 5.5 6.0 SO ₃ % max ≤3.0 ≤4.0 ≤4.0 2.4 1.9 1.8 S% max ≤2.0 ≤2.0 - 0.1 0.1 0.2 Insoluble residue% maximum ≤1.0 ≤1.0 ≤1.0 0.6 0.9 2.0 Ignition loss% maximum ≤3.0 ≤4.0 ≤5.0 3.1 4.7 8.9 SiO ₂ % - - - 22.4 22.7 19.7 Al ₂ O ₃ % - - - 5.6 6.5 8.1 CaO% - - - 59.4 57.5 58.4 Na ₂ O% - - - 0.25 0.21 0.21 K ₂ O% - - - 0.44 0.34 0.26 Alkali (Na ₂ O%+0.658 K ₂ O%) - - - 0.53 0.44 0.38

From the data recorded in Table 5 above, it can be clearly known that the various constituents of the functional cement materials AS3, AS4, and AS5 of Example 5 to Example 7 are in line with or close to the IS (<70) type specified by CNS 15286, respectively. The reference standard value of IS(70) type and IP type. Therefore, it can be considered that the functional cement material to which the cement modifier of the present invention is added is suitable for use as a material for hydraulic cement.

However, the above are only preferred embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention, that is, simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the description of the invention , Are still within the scope of the invention patent.

S1: Raw material crushing process S2: Iron separation process S3: Secondary refinement process S4: Micro powdering process 10: The first crushing unit 20: Magnetic separation unit 30: The second crushing unit 50: Grinding unit 51: Grinding Disc 52: Roller 53: Inlet 54: Outlet F: Iron material Sb: reduction ballast Sc: first refinement Sd: tailings Sf: secondary refinement Sg: cement modifier

Figure 1 is a standard flow chart showing the manufacturing method of the cement modifier of the present invention. 2 is a schematic diagram showing the structure of the manufacturing system of the cement modifier of the present invention. Fig. 3 is a schematic diagram of the structure of the grinding unit in the manufacturing system of the cement modifier of the present invention.

S1: Raw material crushing process

S2: Iron separation process

S3: Secondary refinement process

S4: Micro powdering process

Claims (10)

A method for manufacturing a cement modifier, which is suitable for recycling the reduced ballast of an electric arc furnace to produce a cement modifier. The first crushing step of the chemical product; the raw material belongs to steel ballast, and at least contains the reduced ballast from the electric arc furnace. The average particle size of the first refined product is less than 20 mm; the iron separation process is at least capable of using magnetic force to remove The first step of refining the iron-containing components in the product to obtain the first magnetic separation step of the tailings, the magnetic force is derived from a magnetic force generating device; the second refining process, which is obtained by at least further refining and pulverizing the tailings The secondary pulverization step of the secondary refined product, the average particle size of the secondary refined product is less than 5 mm; and the fine powdering process, which is at least capable of further finely grinding the secondary refined product into reduced ballast micro Powder to obtain a fine powdering step of cement modifier; wherein the content of calcium oxide in the cement modifier is 55%~57%, the content of aluminum oxide is 10.7%~11.1%, and the content of silicon dioxide is 16% ~18%, the magnesium oxide content is 8%~9%. The method for manufacturing a cement modifier according to claim 1, wherein the alkalinity of the cement modifier is in the range of 1.5 to 3.5; the alkalinity (Alk) refers to the calcium oxide content in the cement modifier The ratio of (CaO%) to the sum of silicon dioxide content (SiO ₂ %) and phosphorus pentoxide content (P ₂ O ₅ %): Alk=(CaO%)/〔(SiO ₂ %)+(P ₂ O ₅ %)]. The method for manufacturing a cement modifier according to claim 1, wherein the _{content of dicalcium silicate (C 2} S) of the cement modifier is 30%-40%, and the content of tricalcium silicate (C ₃ S) The content is 11% to 14%, and the content of tricalcium aluminate (C ₃ A) is 26% to 27%. The method for manufacturing a cement modifier according to claim 1, wherein the fineness (specific surface area) of the cement modifier measured by the air permeability method is 500 m ² /kg or more. A method for manufacturing a functional cement material, which includes uniformly mixing a cement modifier prepared by the manufacturing method described in any one of claims 1 to 3 and Portland cement at a specific mixing ratio. Obtain functional cement; wherein the blending ratio of the cement modifier and the portland cement is in the range of 1:10-10:1; the total content of the furnace stone, fly ash and lime in the portland cement Is less than 5%; the calcium oxide content in the cement modifier is 55%~57%, the aluminum oxide content is 10.7%~11.1%, the silicon dioxide content is 16%~18%, and the magnesium oxide content is 8%~9%; alkalinity is 3.2~3.4; the _{content of dicalcium silicate (C 2} S) of the cement modifier is 30%~40%, and _{the content of tricalcium silicate (C 3} S) is 11 %~14%, _{the content of tricalcium aluminate (C 3} A) is 26%~27%; and the activity coefficient of this functional cement is higher than 75% on the 28th day. The method for manufacturing functional cement according to claim 5, wherein the blending ratio of the cement modifier and the Portland cement is in the range of 1:8-8:1. The method for producing functional cement according to claim 5, wherein the fineness (specific surface area) of the cement modifier measured by the air permeability method is 500 m ² /kg or more. A functional cement material, which is obtained by the manufacturing method according to any one of claims 5 to 7, or the cement modifier according to any one of claims 1 to 3 in a specific blending ratio It is blended with Portland cement; wherein the fineness (specific surface area) of the cement modifier measured by the air permeability tester is above 500m ² /kg; the cement modifier contains two silicates The content of calcium (C ₂ S) is 30% to 40%, the content of tricalcium silicate (C ₃ S) is 11% to 15%, and the content of tricalcium aluminate (C ₃ A) is 22% to 27% ; And the alkalinity of the cement modifier is in the range of 1.5~3.5; the alkalinity (Alk) refers to the calcium oxide content (CaO%) in the cement modifier relative to the silica content (SiO ₂ % The ratio of) to the sum of phosphorus pentoxide content (P ₂ O ₅ %): Alk=(CaO%)/[(SiO ₂ %)+(P ₂ O ₅ %)]. The functional cement material described in claim 8, wherein the content of calcium oxide in the cement modifier is 55%~57%, the content of aluminum oxide is 10.5%~11.5%, and the content of silicon dioxide is 16%~ 18%, the magnesium oxide content is 8%-9%. The functional cement material according to claim 8, wherein the fineness (specific surface area) of the cement modifier measured by the air permeability meter method is 1000 m ² /kg or more.

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