Modified slag and preparation method thereof, and modified slag mortar building block and preparation method thereof

Abstract

The invention relates to the technical field of building material preparation, in particular to modified slag and a preparation method thereof, and a modified slag mortar building block and a preparation method thereof. The preparation method of the modified slag comprises the following steps: mixing and stirring fly ash, silica fume, mineral powder, carbide slag and mirabilite according to a mass ratio of (48-55): (17-20): (17-20): (1-5): (1-5) to obtain a geopolymer; geopolymer is used for spraying common slag, and then the modified slag is obtained through maintenance. According to the invention, industrial by-products such as fly ash, silica fume, mineral powder, carbide slag and mirabilite in a specific mass ratio are used as raw materials for spraying modification of the slag, so that the loose and porous characteristics of the slag can be improved, the cylinder compressive strength of the slag can be improved, and the water absorption rate can be reduced; and the modified slag obtained by the preparation method can be used for preparing high-strength mortar building blocks, and can be widely applied to building materials.

Description

Technical Field

[0001] The invention relates to the technical field of building material preparation, and in particular to modified slag and a preparation method thereof, and a modified slag mortar block and a preparation method thereof. Background Art

[0002] Slag is industrial solid waste, which is the waste residue from coal burning in thermal power plants, industrial and civil boilers and other equipment. It is also called coal slag or molten slag. The industrial slag output is huge, but the actual utilization rate is extremely low, which has caused pollution problems. How to effectively utilize slag is a difficult problem. At present, the utilization value of slag is still very low. Its main uses are brick making and paving. However, bricks mixed with slag are prone to cracking, and paving cannot utilize the chemical properties of slag, resulting in a waste of resources. Slag has the characteristics of hard texture, looseness, porosity, irregular shape, high output, large loss on ignition, and low utilization rate. When slag is used as aggregate to prepare mortar, its looseness, porosity and irregular shape are magnified, resulting in a significant decrease in the strength of the mortar. Therefore, the resource utilization of slag has become an urgent problem to be solved. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a modified slag and a preparation method, a modified slag mortar block and a preparation method, aiming to solve the problem of low strength of the mortar prepared from the existing slag.

[0004] The technical solution of the present invention is as follows:

[0005] A first aspect of the present invention provides a method for preparing modified slag, comprising:

[0006] Step S1, mixing fly ash, microsilica powder, mineral powder, carbide slag and thenardite, wherein the mass ratio of the fly ash, microsilica powder, mineral powder, carbide slag and thenardite is 48-55:17-20:17-20:1-5:1-5, to obtain a geopolymer;

[0007] Step S2: spraying the common slag with the geopolymer obtained in step S1, and then curing the slag to obtain the modified slag.

[0008] Optionally, the step S2 specifically includes:

[0009] The geopolymer obtained in step S1 is placed in a sprayer, and the common slag is placed in a granulator. The surface of the common slag is first soaked with a spray pot filled with water, and then the geopolymer is used to spray the common slag. When the surface of the common slag is coated with the geopolymer, water is sprayed. The operation of spraying water and geopolymer on the surface of the common slag is repeated many times. The whole process is controlled within 20 minutes to obtain the slag with the surface coated with the geopolymer, and then cured at 40-60° C. for 1-7 days to obtain the modified slag.

[0010] Optionally, the mass ratio of the geopolymer to the ordinary slag is 0.5-2:4-6, and the mass ratio of the geopolymer to the water is 1:0.15-0.35.

[0011] Optionally, the rotation speed of the granulator is 20-40 r / min, and the inclination angle is 40°-60°.

[0012] In the second aspect of the present invention, there is provided a modified slag prepared by using the preparation method of the modified slag described in the present invention.

[0013] In the third aspect of the present invention, there is provided a preparation method of a modified slag mortar block, which includes:

[0014] Step S11: Mix the modified slag prepared by using the preparation method of the modified slag described in the present invention and ordinary slag to obtain a mixed slag, and then add cement and water and mix and stir to obtain a mortar;

[0015] Step S12: Put the mortar obtained in step S11 into a mold for molding, and obtain the modified slag mortar block after curing and demolding.

[0016] Optionally, in step S11, the particle size of the modified slag is 1.18-4.75 mm.

[0017] Optionally, in step S11, the mass ratio of the mixed slag to the cement is 1-3:1, and the ratio of the total mass of the mixed slag and the cement to the mass of the water is 1:0.2-0.25.

[0018] Optionally, in step S12, the curing conditions include: temperature 20-30 °C, humidity 94%-99%, and time 1-28 days.

[0019] In the fourth aspect of the present invention, there is provided a modified slag mortar block prepared by using the preparation method of the modified slag mortar block described in the present invention.

[0020] Beneficial effects: The present invention sprays and modifies the slag by using industrial by-products such as fly ash, microsilica powder, mineral powder, carbide slag and sodium sulfate with a specific mass ratio as the modification raw materials. On the one hand, carbide slag and sodium sulfate can complexly activate fly ash, microsilica powder and mineral powder to form a geopolymer, and the geopolymer forms a film on the surface of the slag, which can improve the loose and porous characteristics of the slag, is beneficial to improving the cylinder compressive strength of the slag, and reducing the water absorption rate; on the other hand, using the industrial by-products as the modification raw materials can save resources, reduce costs, and is green and environmentally friendly. The modified slag obtained by the preparation method of the present invention can be used to prepare high-strength mortar blocks and can be widely used in building materials. Brief Description of the Drawings

[0021] Figure 1 It is a flowchart of a preparation method of a modified slag provided by the present invention.

[0022] Figure 2 It is a flowchart of a preparation method of a modified slag mortar block provided by the present invention. Detailed Embodiments

[0023] The present invention provides a modified slag and a preparation method thereof, a modified slag mortar block and a preparation method thereof. To make the objectives, technical solutions and effects of the present invention clearer and more definite, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] As Figure 1 shown, an embodiment of the present invention provides a preparation method of a modified slag, which includes:

[0025] Step S1: Mix and stir fly ash, microsilica powder, mineral powder, carbide slag and sodium sulfate. The mass ratio of the fly ash, microsilica powder, mineral powder, carbide slag and sodium sulfate is 48-55:17-20:17-20:1-5:1-5 to obtain a geopolymer;

[0026] Step S2: Spray the ordinary slag with the geopolymer obtained in Step S1, and then cure to obtain the modified slag.

[0027] In the embodiment of the present invention, industrial by-products such as fly ash, microsilica powder, mineral powder, carbide slag and sodium sulfate with a specific mass ratio are first used as modification raw materials. Among them, carbide slag and sodium sulfate can complexly activate fly ash, microsilica powder and mineral powder to form a geopolymer, and then the geopolymer is used to spray and modify the surface of the slag. The geopolymer forms a protective shell on the surface of the slag, which can improve the characteristics of the slag being loose and porous, is beneficial to improving the cylinder compressive strength of the slag, and reducing the water absorption rate; and in the embodiment of the present invention, using the industrial by-products as modification raw materials can save resources, reduce costs, and is environmentally friendly.

[0028] In the embodiments of the present invention, the principle of using carbide slag and sodium sulfate to compound and activate fly ash, microsilica powder and mineral powder to form geopolymers for slag modification is as follows: Carbide slag and sodium sulfate act as compound activators to react with fly ash, microsilica powder and mineral powder to produce a synergistic mechanism. The NaOH generated by the reaction of carbide slag and sodium sulfate in the slurry has strong alkalinity. Under such strong alkaline conditions, the oxide minerals in fly ash, microsilica powder and mineral powder decompose into monomers, and the monomers formed by dissolving the oxide minerals will condense and polymerize to form polysialic acid long chains with different silicon-aluminum ratios. The polysialic acid long chains crosslink and polymerize with each other to form a three-dimensional aluminosilicate gel structure, which is a disordered alkaline aluminosilicate gel mainly composed of -Al-O- tetrahedrons and -Si-O- octahedrons, that is, geopolymers. The formation of this gel material is beneficial to the progress of the reaction, and the generated CaSO4 is the upstream raw material for the formation of ettringite, which is beneficial to the strength development of the cementitious material, thereby improving the cylinder compressive strength of the modified slag. And by spraying the geopolymer on the surface of the slag, the characteristics of the slag being loose and porous are improved, thereby reducing the water absorption rate of the slag. Using the said geopolymer to modify the slag can form a protective shell on the surface of the slag, which can improve the characteristics of the slag being loose and porous, is beneficial to improving the cylinder compressive strength of the slag, and reducing the water absorption rate.

[0029] The preparation method of a modified slag provided by the embodiments of the present invention has the following technical advantages:

[0030] (1) Different from the existing slag resource utilization technologies, the raw material pretreatment of this product only needs to be screened after air drying or drying in the natural state, which can significantly reduce production costs while reducing carbon emissions and accelerating the production rhythm.

[0031] (2) Using fly ash, microsilica powder, mineral powder, and the compound activator is carbide slag and sodium sulfate, all of which are industrial by-products. It not only has low cost but also can consume solid waste, and has the advantages of environmental protection and low cost. In addition, in the preparation method of the present invention, there is no need to add other substances to adjust the strong alkaline environment required for the reaction. The compound activator used in the present invention is carbide slag and sodium sulfate, and the NaOH generated by the reaction in the slurry directly provides a strong alkaline environment for the reaction.

[0032] (3) Using industrial by-products such as fly ash, microsilica powder, mineral powder, carbide slag and sodium sulfate to mix and form geopolymers. The geopolymers form a protective shell on the surface of the slag, which can improve the characteristics of the slag being loose and porous, is beneficial to improving the cylinder compressive strength of the slag, and reducing the water absorption rate.

[0033] In some embodiments, the mass ratio of the fly ash, microsilica powder, mineral powder, carbide slag and sodium sulfate is 48-55:17-20:17-20:1-5:1-5. The raw material dosage within this range can better improve the cylinder compressive strength of the modified slag.

[0034] In some embodiments, step S2 specifically includes:

[0035] Put the geopolymers obtained in step S1 into a spraying machine, and put the ordinary slag into a granulating machine. First, wet the surface of the ordinary slag with a watering can filled with water, and then spray the geopolymers on the ordinary slag. After the surface of the ordinary slag is wrapped with geopolymers, spray water. Repeat the operations of spraying water and geopolymers on the surface of the ordinary slag in sequence for multiple times. The whole process is controlled within 20 minutes to obtain slag with geopolymers wrapped on the surface, and then cure it at 40-60 °C for 1-7 days to obtain modified slag.

[0036] In this embodiment, spraying the ordinary slag with geopolymers makes the raw materials of the geopolymers and the slag wrap more tightly and not easy to fall off, forming a thin film of geopolymers on the surface of the slag to obtain modified slag.

[0037] In some embodiments, the mass ratio of the geopolymers to the ordinary slag is 0.5-2:4-6, and the mass ratio of the geopolymers to the water (referring to the total water consumption in step S2) is 1:0.15-0.35.

[0038] In some embodiments, the rotational speed of the granulating machine is 20-40 r / min, and the inclination angle is 40°-60°.

[0039] In some embodiments, the particle size of the ordinary slag in step S2 is 1.18-4.75 mm. The oxide content in the ordinary slag is calculated by mass fraction, which is SiO2: 40%-50%, Al2O3: 10%-15%, Fe2O3: 8%-10%, CaO: 80%-10%, MgO: 3%-4%, Na2O: 2%-3%.

[0040] The embodiment of the present invention provides modified slag prepared by using the preparation method of modified slag described in any of the foregoing embodiments. The modified slag obtained by the preparation method of the present invention has high cylinder compressive strength and low water absorption rate, and has strength support whether it is used to prepare high-strength concrete or masonry mortar in the later stage, and has a wide application range.

[0041] As Figure 2 shown, the embodiment of the present invention provides a preparation method of a modified slag mortar block, which includes:

[0042] Step S11: Mix the modified slag prepared by using the preparation method of modified slag described in any of the foregoing embodiments of the present invention and ordinary slag to obtain mixed slag, and then add cement and water and mix and stir to obtain mortar;

[0043] Step S12: Put the mortar obtained in step S11 into a mold for molding, and after curing and demolding, the modified slag mortar block is obtained.

[0044] In the embodiment of the present invention, the modified slag obtained by using the preparation method described in the foregoing embodiment of the present invention is mixed with ordinary slag, and then cement and water are added and mixed and stirred to obtain high-strength modified slag mortar. After steps such as molding and curing, high-strength mortar blocks are obtained.

[0045] In some embodiments, in step S11, the particle size of the modified slag is 1.18 - 4.75 mm.

[0046] In some embodiments, in step S11, by mass, the gradation of the mixed slag (referring to the particle size distribution of the slag in the mixed slag) is 4.75 - 2.36 mm: 0 - 10 parts, 2.36 - 1.18 mm: 10 - 15 parts, 1.18 - 0.6 mm: 10 - 25 parts, 0.6 - 0.3 mm: 20 - 31 parts, 0.3 - 0.15 mm: 20 - 30 parts, <0.15 mm: 5 - 15 parts. The particle size of the modified slag used is 1.18 - 4.75 mm, and the slag with other particle sizes uses unmodified slag. The slag with a particle size below 1.18 mm is small in particle size and water needs to be added during the modification process. The slag with a small particle size is prone to agglomeration and caking by itself, affecting the treatment effect. The slag with a particle size above 1.18 mm is easier to be modified, and the effect on improving the cylinder compressive strength of the slag is more obvious.

[0047] In some embodiments, in step S11, the mass ratio of the mixed slag to the cement is 1 - 3:1, and the ratio of the total mass of the mixed slag and the cement to the mass of the water is 1:0.2 - 0.25.

[0048] In some embodiments, the curing conditions include: temperature is 20 - 30 °C, humidity is 94% - 99%, and time is 1 - 28 days.

[0049] The preparation method of a modified slag mortar block provided by the embodiment of the present invention specifically includes:

[0050] Step S21: Mix and stir fly ash, microsilica, mineral powder, carbide slag and sodium sulfate. The mass ratio of fly ash, microsilica, mineral powder, carbide slag and sodium sulfate is 48 - 55:17 - 20:17 - 20:1 - 5:1 - 5 to obtain geopolymers.

[0051] Step S22: Spray the ordinary slag with the geopolymers obtained in step S21, and then obtain modified slag after curing.

[0052] Step S23: Mix the modified slag obtained in step S22 with ordinary slag to obtain a mixed slag, and then add cement and water and mix and stir to obtain mortar.

[0053] Step S24: Put the mortar obtained in step S23 into a mold for molding, and after curing and demolding, obtain the modified slag mortar block.

[0054] In this article, the cement used is P.O.42.5 cement, which complies with the General Portland Cement Standard GB175-2007; the fly ash used is Class II ash, which complies with the standard GB1596-91; the microsilica powder, mineral powder, carbide slag and sodium sulfate used are solid wastes generated industrially, and all are obtained through procurement to ensure that their quality complies with relevant standards.

[0055] An embodiment of the present invention provides a modified slag mortar block prepared by using the preparation method of the modified slag mortar block described in any one of the foregoing embodiments of the present invention.

[0056] The present invention will be further described below through specific embodiments.

[0057] Example 1

[0058] This embodiment provides a preparation method of a modified slag mortar block, which specifically includes the following steps:

[0059] Step 1: Weigh fly ash, microsilica powder, mineral powder, carbide slag, and sodium sulfate in a mass ratio of 54:18:18:5:5, and directly put them into a cement mortar mixer for mixing and stirring to obtain geopolymers after uniform stirring.

[0060] Step 2: Put the obtained geopolymers into a powder spraying machine, and put ordinary slag into a granulator. The particle size of the ordinary slag used is 1.18 - 4.75 mm. The mass ratio of geopolymers to ordinary slag is 1:5. Control the rotation speed of the granulator at 30 r / min and the inclination angle at 50°. First, wet the surface of the slag with a watering can filled with water, and then spray the geopolymers on the ordinary slag. After the surface of the ordinary slag is coated with geopolymers, spray water again. Repeat the operations of spraying water and geopolymers on the surface of the ordinary slag in this way for many times. Control the mass ratio of geopolymers to water at 1:0.3, and control the entire test time within 20 minutes to obtain modified slag. Put the modified slag into a curing box at 40 - 60 °C for one day of curing.

[0061] Step 3: After well-curing the modified slag with a particle size of 1.18 - 4.75 mm and ordinary slag with other particle sizes according to a certain gradation, a mixed slag is obtained. The gradation of the mixed slag is as follows: 4.75 - 2.36 mm: 10 parts, 2.36 - 1.18 mm: 5 parts, 1.18 - 0.6 mm: 10 parts, 0.6 - 0.3 mm: 15 parts, 0.3 - 0.15 mm: 45 parts, <0.15 mm: 15 parts. Take the prepared mixed slag as the aggregate, add cement and stir in a cement mortar mixer for 180 s, wherein the mass ratio of the mixed slag to the cement is controlled to be 1:3. Then add water and stir for 600 s until the slurry is evenly mixed, wherein the ratio of the total mass of the mixed slag and the cement to the mass of water is controlled to be 1:0.25 to obtain the mortar.

[0062] Step 4: Pour the obtained well-stirred mortar into a mold of 40×40×160 mm 3 , vibrate on a vibrating table for 120 s, scrape the surface flat, cover it with a plastic wrap, and then place it in a curing box at a temperature of 20 °C and a humidity of 98% for 28 days to obtain the modified slag mortar block.

[0063] Example 2

[0064] The preparation method of Example 2 is the same as that of Example 1, except that the mass ratio of fly ash, microsilica, mineral powder, carbide slag, and sodium sulfate in Step 1 is adjusted to 54:19:17:5:5.

[0065] Example 3

[0066] The preparation method of Example 3 is the same as that of Example 1, except that the mass ratio of fly ash, microsilica, mineral powder, carbide slag, and sodium sulfate in Step 1 is adjusted to 54:19:19:4:4.

[0067] Example 4

[0068] The preparation method of Example 4 is the same as that of Example 1, except that the mass ratio of fly ash, microsilica, mineral powder, carbide slag, and sodium sulfate in Step 1 is adjusted to 54:20:20:3:3.

[0069] Example 5

[0070] The preparation method of Example 5 is the same as that of Example 1, except that the mass ratio of fly ash, microsilica, mineral powder, carbide slag, and sodium sulfate in Step 1 is adjusted to 50:20:20:5:5.

[0071] Comparative Example 1

[0072] The preparation method of Comparative Example 1 is the same as that of Example 1, except that the mass ratio of fly ash, microsilica, mineral powder, carbide slag, and sodium sulfate in Step 1 is adjusted to 54:18:18:6:4.

[0073] Comparative Example 2

[0074] The preparation method of Comparative Example 2 is the same as that of Example 1, except that the mass ratio of fly ash, microsilica powder, slag powder, carbide slag, and sodium sulfate in Step 1 is adjusted to 54:18:18:4:6.

[0075] Comparative Example 3

[0076] The preparation method of Comparative Example 3 is the same as that of Example 1, except that the mass ratio of fly ash, microsilica powder, slag powder, carbide slag, and sodium sulfate in Step 1 is adjusted to 54:15:23:4:4.

[0077] Comparative Example 4

[0078] The preparation method of Comparative Example 4 is the same as that of Example 1, except that the mass ratio of fly ash, microsilica powder, slag powder, carbide slag, and sodium sulfate in Step 1 is adjusted to 54:24:16:3:3.

[0079] For the modified slag obtained through Step 1 and Step 2 in the above Examples 1 - 5 and Comparative Examples 1 - 4, performance tests of cylinder compressive strength and water absorption were carried out. The test methods are as follows:

[0080] Cylinder compressive strength (using the arithmetic mean of three measured values as the test result): Take 15L - 20L of slag, place it in a drying oven and dry it to equilibrium, divide it into two parts for standby. Use a sampling spoon to evenly pour the sample from 50 mm above the container mouth, allowing the sample to fall naturally without colliding with the measuring cylinder. After filling, make the sample above the measuring cylinder mouth form a cone. Use a bearing cylinder with a bottom to load the sample until it is higher than the cylinder mouth, place it on a concrete test vibrating table and vibrate for 3 s, then load the sample again until it is higher than the cylinder mouth, place it on the vibrating table and vibrate for 5 s, scrape (or supplement) the sample even with the cylinder mouth. Install the guiding cylinder and the stamping die. Align the lower scale line of the stamping die with the upper edge of the guiding cylinder. Place the bearing cylinder on the lower platen of the press, align it with the center of the platen, and apply a load uniformly at a speed of 300N - 500N per second. When the stamping die is pressed into a depth of 20 mm, record the pressure value. Calculation formula: Fa = (p1 + p2) / F, where Fa is the cylinder compressive strength of the coarse aggregate (MPa), p1 is the pressure value (N) when the pressing depth is 20 mm; p2 is the mass of the stamping die (N), and F is the bearing area (i.e., the area of the stamping die F = 10000 mm 2 )

[0081] Water absorption rate (the arithmetic mean of three measurement values is taken as the test result): Take 4L of the specimen, dry it to a constant weight, and set it aside. Divide the specimen into three equal parts, weigh them separately, and then place them in a container filled with water (if there are particles floating on the water surface, they should be pressed into the water). After the specimen is immersed in water for 1h (if there are particles floating on the water surface, a round metal plate with a handle should be used to press them into the water), take it out, pour it onto a 1.18mm sieve, and filter the water for 1min - 2min. Then pour it onto a wrung-out wet towel, hold both ends of the towel with water to make it in a trough shape, let the aggregate roll back and forth on the towel 8 - 10 times, then pour it into an enamel tray, make the specimen surface dry and saturated, and then weigh it. The water absorption rate is calculated according to the following formula, and the calculation is accurate to 0.1%.

[0082] Wa = (m0 - m1) / m1 × 100, where Wa is the water absorption rate in 1h (%), m0 is the mass of the immersed specimen (g), and m1 is the mass of the dried specimen (g).

[0083] For the modified slag mortar blocks finally prepared in the above Examples 1 - 5 and Comparative Examples 1 - 4, performance testing of the block strength was carried out. The testing method for the block strength is as follows: The compressive strength test is carried out on the side surface of a semi - prism through a pressure testing instrument. The difference between the center of the semi - prism and the center of the pressure plate of the press should be within ±0.5mm, and the part of the prism exposed outside the press plate is about 10mm. During the entire loading process, the load is uniformly applied at a rate of 2400N / s ± 200N / s until failure. The compressive strength Rc is in units of newtons per square millimeter (MPa) and is calculated according to the following formula:

[0084] Rc = Fc / A, where: Fc is the maximum load at failure, N; A is the area of the compressed part, mm 2 (40mm ± 40mm ± 1600mm 2 )。

[0085] The specific performance data are shown in Table 1.

[0086] Table 1

[0087]

[0088]

[0089] It can be seen from the data in Table 1 that compared with Comparative Examples 1 - 4, using geopolymers formed from fly ash, microsilica, slag powder, carbide slag, and sodium sulfate with specific mass ratios in the preparation method of the present invention to spray - modify ordinary slag, the modified slag obtained has higher cylinder compressive strength and lower water absorption rate, and the mortar blocks made of the said modified slag also have higher strength.

[0090] In summary, by using industrial by-products such as fly ash, microsilica powder, slag powder, carbide slag, and sodium sulfate with a specific mass ratio as the modification raw materials to spray-modify the slag, the present invention can improve the cylinder compressive strength of the slag, reduce the water absorption rate, and the modified slag obtained by the preparation method of the present invention can be used to prepare high-strength mortar blocks, which can be widely applied to building materials.

[0091] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for preparing modified slag, characterized in that: include: Step S1, mixing fly ash, microsilica powder, mineral powder, carbide slag and thenardite, wherein the mass ratio of the fly ash, microsilica powder, mineral powder, carbide slag and thenardite is 48-55:17-20:17-20:1-5:1-5, to obtain a geopolymer; Step S2: spraying the common slag with the geopolymer obtained in step S1, and then curing the slag to obtain the modified slag.

2. The method for preparing modified slag according to claim 1, characterized in that: The step S2 specifically includes: The geopolymer obtained in step S1 is placed in a sprayer, and the common slag is placed in a granulator. The surface of the common slag is first soaked with a spray pot filled with water, and then the geopolymer is used to spray the common slag. When the surface of the common slag is coated with the geopolymer, water is sprayed. The operation of spraying water and geopolymer on the surface of the common slag is repeated many times. The whole process is controlled within 20 minutes to obtain the slag with the surface coated with the geopolymer, and then cured at 40-60° C. for 1-7 days to obtain the modified slag.

3. The method for preparing modified slag according to claim 2, characterized in that: The mass ratio of the geopolymer to the common slag is 0.5-2:4-6, and the mass ratio of the geopolymer to the water is 1:0.15-0.

35.

4. The method for preparing modified slag according to claim 2, characterized in that: The rotation speed of the granulator is 20-40 r / min, and the inclination angle is 40°-60°.

5. A modified slag prepared by the method for preparing modified slag according to any one of claims 1 to 4.

6. A method for preparing a modified slag mortar block, characterized in that: include: Step S11, mixing the modified slag prepared by the method for preparing the modified slag according to any one of claims 1 to 4 with ordinary slag to obtain mixed slag, and then adding cement and water to mix and stir to obtain mortar; Step S12, placing the mortar obtained in step S11 into a mold for molding, and obtaining the modified slag mortar block after curing and demoulding.

7. The method for preparing the modified slag mortar block according to claim 6, characterized in that: In the step S11, the particle size of the modified slag is 1.18-4.75 mm.

8. The method for preparing the modified slag mortar block according to claim 6, characterized in that: In the step S11, the mass ratio of the mixed slag to the cement is 1-3:1, and the ratio of the total mass of the mixed slag and the cement to the mass of the water is 1:0.2-0.

25.

9. The method for preparing the modified slag mortar block according to claim 6, characterized in that: In the step S12, the curing conditions include: a temperature of 20 to 30°C, a humidity of 94% to 99%, and a time of 1 to 28 days.

10. A modified slag mortar block prepared by the method for preparing a modified slag mortar block according to any one of claims 6 to 9.

Images