Preparation method of modified steel slag powder applied to cold-mixed full-steel-slag asphalt mixture

Abstract

The invention relates to the technical field of modified steel slag powder, and discloses a preparation method of modified steel slag powder applied to a cold-mixed full-steel-slag asphalt mixture, which comprises the following preparation steps: 1) stirring and mixing 80-90 parts by mass of steel slag, 10-20 parts by mass of waste slurry powder particles and 1-2 parts by mass of triethanolamine in a stirring drum to form a mixture; 2) grinding the mixture in a ball mill for a set time to form powder; 3) drying the powder in a dryer to obtain modified steel slag powder; through the preparation steps, the activity, the particle distribution uniformity, the compatibility with the emulsified asphalt and the chemical stability of the modified steel slag powder are remarkably improved, so that a higher-quality material choice is provided for the application of the cold-mixed full-steel-slag asphalt mixture.

Description

Technical Field

[0001] The patent of this invention relates to the technical field of modified steel slag powder, specifically, to a method for preparing modified steel slag powder used in cold-mixed all-steel slag asphalt mixture. Background Art

[0002] Steel slag is a by-product of the steelmaking process. It has excellent physical and mechanical properties such as high hardness, high density, high strength, good wear resistance, and strong alkalinity. Its main application areas include cement concrete admixtures and highway construction materials.

[0003] However, the application of steel slag in highway construction materials is restricted. The main factor is that steel slag contains some free calcium oxide (CaO) and magnesium oxide (MgO). These two substances will react with water in the early stage of use, causing volume expansion. Therefore, whether used as an admixture for cement concrete or as an aggregate for asphalt mixture, steel slag has certain risks. Moreover, its research and application in asphalt mixtures are limited to hot-mix asphalt mixtures. Currently, there are very few reports on the preparation of steel slag asphalt mixtures using the cold mix method.

[0004] In the prior art, free calcium oxide (CaO) and magnesium oxide (MgO) in steel slag consume a large amount of water when reacting with water, resulting in insufficient activity in the subsequent modified steel slag powder. Furthermore, during the preparation process of the modified steel slag powder, additives that can effectively enhance its activity, such as triethanolamine, are not added. Therefore, its activity in cold-mix all-steel slag asphalt mixtures is relatively poor.

[0005] In addition, the hardness of steel slag is relatively high. After crushing and screening, the particle size distribution of the steel slag powder is uneven, and there are many large particles. These large particles will affect the uniformity and density of the cold-mixed all-steel slag asphalt mixture, thereby reducing the overall performance of the mixture.

[0006] In addition, the free calcium oxide (CaO) and magnesium oxide (MgO) in the steel slag react with the water used to demulsify the emulsified asphalt to generate alkaline products. These alkaline products will form an alkaline product-mortar transition bonding layer between the surface of the steel slag aggregate and the asphalt film. Although this bonding layer can solve the hazard of water expansion of the steel slag material, it can also lead to insufficient bonding between the steel slag aggregate and the asphalt film, affecting the overall performance of the mixture, and making the subsequent modified steel slag powder unable to meet the requirements in terms of compatibility with the emulsified asphalt. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for preparing modified steel slag powder for use in cold-mix all-steel slag asphalt mixture, aiming to solve the problem in the prior art that the modified steel slag powder has insufficient performance when used in cold-mix all-steel slag asphalt mixture.

[0008] The present invention is achieved by preparing a modified steel slag powder for use in a cold-mix all-steel slag asphalt mixture, comprising the following preparation steps:

[0009] 1) Place 80-90 parts of steel slag, 10-20 parts of waste pulp powder and 1-2 parts of triethanolamine in a mixing drum and stir to form a mixture;

[0010] 2) Grinding the mixed material in a ball mill for a set time to form a powder;

[0011] 3) The powder is placed in a dryer for drying to obtain modified steel slag powder.

[0012] Furthermore, in the preparation step 1), the particle size of the steel slag is between 0.1 mm and 0.3 mm.

[0013] Furthermore, in the preparation step 2), the mixed material is ground in a ball mill for 8 to 10 hours to form the powder.

[0014] Furthermore, in the preparation step 2), the powder has a fineness of 0.075 mm and a passing rate through a standard square hole sieve of 98% or more.

[0015] Furthermore, in the preparation step 3), the dryer has a drying chamber, the drying temperature of the drying chamber is between 90°C and 100°C, and the powder is placed in the drying chamber and dried for a set time to obtain the modified steel slag powder.

[0016] Furthermore, in the preparation step 3), the powder is dried in a drying chamber for 1 to 2 hours to form modified steel slag powder.

[0017] Furthermore, in the preparation step 1), the waste pulp particles are white mud at the bottom of a sedimentation tank in a paper mill, and the waste pulp particles contain calcium carbonate and pulping fibers.

[0018] Furthermore, in the preparation step 1), the waste pulp particles are placed in the mixing drum, and are first dried and crushed in sequence, and the crushed waste pulp particles are placed in the mixing drum.

[0019] Furthermore, in the preparation step 3), the dryer has a longitudinally arranged drying chamber, the drying chamber is provided with a plurality of powder filter plates, each having a plurality of powder filter holes; the plurality of powder filter plates are sequentially spaced along the height direction of the drying chamber to divide the drying chamber into a plurality of drying sections, and the plurality of drying sections are sequentially connected and arranged from top to bottom;

[0020] In the preparation step 3), after the drying chamber is heated to a set temperature, the air in the drying chamber becomes hot air; the powder is placed on the top of the drying chamber, and the powder falls from top to bottom in sequence, passes through multiple powder filter plates, and falls to the bottom of the drying chamber. The hot air in the drying chamber dries the powder that falls in the drying section.

[0021] Furthermore, the bottom of the drying chamber is covered with an elastic membrane layer, the periphery of the elastic membrane layer is fixedly arranged, and the middle portion of the elastic membrane layer is freely arranged, and an air-filled space is formed between the elastic membrane layer and the bottom of the drying chamber;

[0022] When the powder passes through the plurality of powder filter plates in sequence from top to bottom in the drying chamber, the air is inflated or inhaled into the air space by the air inflating and inhaling device, driving the elastic membrane layer to elastically bulge and deform back and forth, and the elastic membrane layer disturbs the falling powder.

[0023] Compared with the prior art, the method for preparing modified steel slag powder for cold-mixed all-steel slag asphalt mixture provided by the present invention has the following advantages:

[0024] 1) By using triethanolamine as an active additive, it can promote a more complete chemical reaction between the active components in the steel slag and the components in the emulsified asphalt, forming a more stable bonding layer, thereby improving the bonding strength and stability of the mixture and enhancing the overall performance of the mixture;

[0025] 2) The ball milling process can effectively refine the particles, making the particle distribution of the powder more uniform, improving the dispersibility of the modified steel slag powder in the cold mix all-steel slag asphalt mixture, thereby enhancing the density and uniformity of the mixture;

[0026] 3) The addition of waste slurry powder helps to improve the surface properties of modified steel slag powder, making it more compatible with emulsified asphalt, reducing the interfacial tension between steel slag powder and emulsified asphalt, enhancing the bonding force between the two, making it easier for steel slag powder to combine with emulsified asphalt, thereby improving the overall performance of the mixture. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic flow chart of a method for preparing modified steel slag powder for use in cold-mix all-steel slag asphalt mixtures provided by the present invention;

[0028] Figure 2 It is a cross-sectional schematic diagram of the drying machine provided by the present invention;

[0029] In the figure: dryer 100, drying chamber 101, powder filter plate 102, elastic membrane layer 103, and inflation space 104. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] The implementation of the present invention is described in detail below with reference to specific embodiments.

[0032] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0033] Reference Figure 1-2 The figure shows a preferred embodiment of the present invention.

[0034] The method for preparing modified steel slag powder used in cold-mix all-steel slag asphalt mixture comprises the following preparation steps:

[0035] 1) Place 80-90 parts of steel slag, 10-20 parts of waste pulp powder and 1-2 parts of triethanolamine in a mixing drum and stir to form a mixture;

[0036] 2) Place the mixed material in a ball mill and grind it for a set time to form a powder;

[0037] 3) The powder is placed in a dryer for drying to obtain modified steel slag powder.

[0038] The above-mentioned method for preparing modified steel slag powder for cold-mix all-steel slag asphalt mixture has the following advantages:

[0039] 1) By using triethanolamine as an active additive, it can promote a more complete chemical reaction between the active components in the steel slag and the components in the emulsified asphalt, forming a more stable bonding layer, thereby improving the bonding strength and stability of the mixture and enhancing the overall performance of the mixture;

[0040] 2) The ball milling process can effectively refine the particles, making the particle distribution of the powder more uniform, improving the dispersibility of the modified steel slag powder in the cold mix all-steel slag asphalt mixture, thereby enhancing the density and uniformity of the mixture;

[0041] 3) The addition of waste slurry powder helps to improve the surface properties of modified steel slag powder, making it more compatible with emulsified asphalt, reducing the interfacial tension between steel slag powder and emulsified asphalt, enhancing the bonding force between the two, making it easier for steel slag powder to combine with emulsified asphalt, thereby improving the overall performance of the mixture.

[0042] In this embodiment, in the preparation step 1), the particle size of the steel slag is between 0.1 mm and 0.3 mm; steel slag in this particle size range is more easily refined during the ball milling process, thereby improving the fineness and uniformity of the final powder. In addition, the smaller particle size helps to reduce the risk of volume expansion of the steel slag in the cold-mixed all-steel slag asphalt mixture, thereby improving the stability and durability of the mixture.

[0043] In this embodiment, in the preparation step 2), the mixed material is ground in a ball mill for 8 to 10 hours to form a powder.

[0044] Through a long grinding process, the fineness and uniformity of the powder can be significantly improved, and the presence of large particles can be reduced, thereby improving the dispersibility and compactness of the modified steel slag powder in the cold-mixed all-steel slag asphalt mixture.

[0045] In this embodiment, in the preparation step 2), the fineness of the powder is 0.075 mm and the pass rate of the standard square hole sieve is more than 98%; by controlling the fineness of the powder, it can be better dispersed in the cold mix all-steel slag asphalt mixture, thereby improving the density and uniformity of the mixture, thereby enhancing the overall performance of the mixture.

[0046] In this embodiment, in the preparation step 3), the dryer has a drying chamber, the drying temperature of the drying chamber is between 90°C and 100°C, and the powder is placed in the drying chamber and dried for a set time to obtain modified steel slag powder.

[0047] Through moderate drying temperature, the moisture in the powder can be effectively removed while maintaining the chemical stability and physical structure of the powder, thereby improving the quality and performance of the modified steel slag powder.

[0048] In this embodiment, in the preparation step 3), the powder is dried in the drying chamber for 1 to 2 hours to form modified steel slag powder.

[0049] By controlling the appropriate drying time, it is possible to ensure that the moisture in the powder is fully removed, while avoiding excessive drying that may lead to a decrease in powder performance, so that the powder can improve the stability and durability of the mixture.

[0050] In this embodiment, in the preparation step 1), the waste pulp particles are white mud at the bottom of the sedimentation tank of the paper mill, and the waste pulp particles contain calcium carbonate and pulping fibers.

[0051] In this way, calcium carbonate can improve the chemical stability and compressive strength of the powder, and pulping fiber can improve the dispersion of the powder and its compatibility with emulsified asphalt. This specific waste slurry powder component can significantly improve the performance of modified steel slag powder, making it more suitable for cold mix all-steel slag asphalt mixture.

[0052] In this embodiment, in the preparation step 1), the waste slurry particles are placed in the mixing drum, and are first dried and crushed in sequence, and the crushed waste slurry particles are placed in the mixing drum.

[0053] Through this pretreatment step, it is possible to ensure that the waste slurry powder particles are fully mixed with other raw materials during the stirring process, which not only improves the dispersibility and uniformity of the waste slurry powder particles, but also improves the overall performance of the modified steel slag powder.

[0054] In this embodiment, in preparation step 3), the dryer 100 includes a longitudinally arranged drying chamber 101, wherein a plurality of powder filter plates 102 are provided in the drying chamber 101, each of which has a plurality of powder filter holes. The plurality of powder filter plates 102 are sequentially spaced along the height direction of the drying chamber 101, dividing the drying chamber 101 into a plurality of drying sections, and the plurality of drying sections are sequentially connected and arranged from top to bottom.

[0055] In preparation step 3), after the drying chamber 101 is heated to a set temperature, the air in the drying chamber 101 becomes hot air; the powder is placed on the top of the drying chamber 101, and the powder falls from top to bottom in sequence, passes through multiple powder filter plates 102, and falls to the bottom of the drying chamber 101. The hot air in the drying chamber 101 dries the powder that falls in the drying section.

[0056] In this way, not only can the powder be evenly heated during the drying process, but the powder filter plate 102 can also screen the powder to ensure the fineness and uniformity of the powder, thereby improving the quality and performance of the powder.

[0057] In this embodiment, the bottom of the drying chamber 101 is covered with an elastic membrane layer 103. The outer periphery of the elastic membrane layer 103 is fixed, and the middle portion of the elastic membrane layer 103 is freely arranged, and the elastic membrane layer 103 and the bottom of the drying chamber 101 are enclosed to form an air-filled space 104.

[0058] When the powder passes through the plurality of powder filter plates 102 in the drying chamber 101 from top to bottom, the air is inflated or inhaled into the air space 104 by the air inflating and inhaling device, driving the elastic membrane layer 103 to elastically bulge and deform back and forth, thereby disturbing the falling powder.

[0059] By arranging the elastic film layer 103 at the bottom of the drying chamber 101 and the coordinated action of the air filling and suction equipment, the dispersion and uniformity of the powder are further improved, ensuring that the powder is fully heated during the drying process, thereby improving the quality and performance of the powder.

[0060] The following will be combined with the embodiments of the present invention to provide a specific, clear and complete description of the technical solutions in the embodiments of the present invention, so that the content of the method for preparing modified steel slag powder used in cold-mixed all-steel slag asphalt mixture is easier to understand:

[0061] 1) Raw materials include: crude steel slag, fine steel slag, modified steel slag powder, triethanolamine, polydimethylsiloxane, fly ash, hydrogen peroxide, emulsified asphalt, water-based epoxy resin, water-based curing agent, and defoaming agent;

[0062] The crude steel slag has a particle size of 4.75-10mm, an abrasion value of ≤30%, and a crushing value of ≤22%, and is derived from electric furnace steel slag tailings.

[0063] Among them, the fine steel slag particle size is 0.075-4.75mm; it comes from electric furnace steel slag tailings;

[0064] Among them, the modified steel slag powder has a particle size of 0-0.075mm and comes from electric furnace steel slag tailings.

[0065] 2) Further, the modified steel slag powder is prepared by uniformly mixing steel slag with a particle size of 0-0.30 mm, waste slurry powder with a particle size of 0-0.30 mm, and triethanolamine in a mass ratio of 80-90 parts: 10-20 parts: 1-2 parts, and then grinding in a ball mill for 8-10 hours until the obtained mixed powder has a fineness of 0.075 mm and a pass rate of 98% or more on a standard square hole sieve. The mixed powder is dried at 90° C. for 1-2 hours to obtain the modified steel slag powder;

[0066] Among them, waste pulp particles are white mud at the bottom of the paper mill sedimentation tank, the main component of which is CaCO3, mixed with a small amount of pulping fiber. Before use, it must be dried and crushed to the required particle size;

[0067] Among them, triethanolamine is a colorless oily liquid, soluble in water, and has the function of aiding grinding;

[0068] Among them, polydimethylsiloxane is non-toxic, colorless and odorless, with a viscosity of about 25mPa.S, has the function of bonding and defoaming, and is industrial grade;

[0069] Among them, the fly ash is secondary fly ash with a specific surface area of ​​4900-5300 cm2 / g and a loss on ignition of 6.9-8.4%;

[0070] Among them, hydrogen peroxide was diluted with a dilution ratio of 1:65 as before;

[0071] The emulsified asphalt is one of cationic medium-cracking emulsified asphalt and cationic slow-cracking emulsified asphalt;

[0072] Among them, the water-based epoxy resin model is E-44, light yellow, and comes from a chemical company;

[0073] Among them, the water-based curing agent is Shuangfenghuang 593 type, which is colorless and transparent, with a viscosity of 125mPa.S, and comes from a chemical company;

[0074] The defoaming agent is one of sodium tetrapropylene benzene sulfonate and sodium lauryl sulfate.

[0075] 3) According to the above, the method for preparing modified steel slag powder for cold mix all-steel slag asphalt mixture further comprises the following steps:

[0076] Add 100 parts by mass of crude steel slag and 40-60 parts by mass of fine steel slag into the asphalt mixing pot and stir for 60-90 seconds;

[0077] Then, 3-5 parts by mass of modified steel slag powder, 1-2 parts by mass of polydimethylsiloxane, 3-5 parts by mass of fly ash, and 1-1.5 parts by mass of hydrogen peroxide are sequentially added to the stirring pot of step 1) and stirred for 60-90 seconds. The mixture is then poured out and air-dried for 30 minutes for later use;

[0078] Add 2-6 parts of emulsified asphalt, 8-12 parts of water-based epoxy resin, 2-6 parts of water-based curing agent and 0.1-0.5 parts of defoaming agent into an empty asphalt mixing pot and stir for 30-60 seconds;

[0079] The mixture obtained in step 2) is added to the asphalt mixing pot in step 3) and stirred for 60-90 seconds; finally, 7-10 parts of modified steel slag powder are added and stirred for another 60-90 seconds to obtain a cold-mixed all-steel slag asphalt mixture.

[0080] Compared with the prior art, the modified steel slag powder preparation method used in the cold mix all-steel slag asphalt mixture of the present invention has the following advantages:

[0081] 1) By selecting steel slag of different particle sizes as aggregate, and taking advantage of its high density, high strength, high polishing value, and good angularity, cold-mix all-steel slag asphalt concrete is prepared. This not only opens up a new way for the resource utilization of industrial waste slag, but also has positive significance in improving the steel slag disposal rate, alleviating the pressure of high-quality stone mining, and promoting the healthy development of the ecological environment, with both significant economic and social benefits.

[0082] 2) The modified steel slag powder of the present invention has a simple preparation process, and papermaking mud is added as a modifier during the preparation process. The raw materials thereof are widely available and meet the requirements of environmental protection and economy. After the modified steel slag powder is used to replace the traditional limestone filler, the free calcium oxide (CaO) and magnesium oxide (MgO) in the steel slag can react with the water used to demulsify the emulsified asphalt. The generated alkaline products can enhance the interfacial adhesion between the steel slag aggregate and the asphalt-based material. At the same time, the hazards caused by the expansion of the steel slag when it comes into contact with water are effectively avoided. In addition, the low-temperature performance of the emulsified asphalt modified with the water-based epoxy resin is also significantly improved.

[0083] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0084] Example 1:

[0085] The invention discloses a preparation method of a cold-mixed all-steel slag asphalt mixture. The raw materials include: coarse steel slag, fine steel slag, modified steel slag powder, triethanolamine, polydimethylsiloxane, fly ash, hydrogen peroxide, emulsified asphalt, water-based epoxy resin, water-based curing agent, and defoaming agent.

[0086] The crude steel slag has a particle size of 4.75-10mm, an abrasion value of ≤30%, and a crushing value of ≤22%, and is derived from electric furnace steel slag tailings.

[0087] Among them, the fine steel slag particle size is 0.075-4.75mm; it comes from electric furnace steel slag tailings;

[0088] Among them, the modified steel slag powder has a particle size of 0-0.075mm and comes from electric furnace steel slag tailings.

[0089] Furthermore, the preparation steps of the modified steel slag powder are: steel slag with a particle size of 0-0.30 mm, waste slurry powder with a particle size of 0-0.30 mm, and triethanolamine are uniformly mixed in a mass ratio of 80 parts: 20 parts: 2 parts, and then placed in a ball mill and ground for 10 hours until the obtained mixed powder has a fineness of 0.075 mm and a standard square hole sieve pass rate of more than 98%. The mixed powder is dried at 90°C for 2 hours to obtain the modified steel slag powder.

[0090] Among them, waste pulp particles are white mud at the bottom of the paper mill sedimentation tank, the main component of which is CaCO3, mixed with a small amount of pulping fiber. Before use, it must be dried and crushed to the required particle size;

[0091] Among them, triethanolamine is a colorless oily liquid, soluble in water, and has the function of aiding grinding;

[0092] Among them, polydimethylsiloxane is non-toxic, colorless and odorless, with a viscosity of about 25mPa.S, has the function of bonding and defoaming, and is industrial grade;

[0093] Among them, the fly ash is secondary fly ash with a specific surface area of ​​4900-5300 cm2 / g and a loss on ignition of 6.9-8.4%;

[0094] Among them, hydrogen peroxide was diluted with a dilution ratio of 1:65 as before;

[0095] The emulsified asphalt is one of cationic medium-cracking emulsified asphalt and cationic slow-cracking emulsified asphalt;

[0096] Among them, the water-based epoxy resin model is E-44, light yellow, and comes from a chemical company;

[0097] Among them, the water-based curing agent is Shuangfenghuang 593 type, which is colorless and transparent, with a viscosity of 125mPa.S, and comes from a chemical company;

[0098] The defoaming agent is one of sodium tetrapropylene benzene sulfonate and sodium lauryl sulfate.

[0099] According to the above, the method for preparing cold-mix all-steel slag asphalt mixture further comprises the following steps:

[0100] 1) Add 100 parts by mass of crude steel slag and 40 parts by mass of fine steel slag into an asphalt mixing pot and stir for 60 seconds;

[0101] 2) Then, 3 parts by mass of modified steel slag powder, 1 part of polydimethylsiloxane, 3 parts of fly ash, and 1 part of hydrogen peroxide were added to the stirring pot in step 1) and stirred for 60 seconds. The mixture was then air-dried for 30 minutes and then poured out for later use;

[0102] 3) Add 4 parts of emulsified asphalt, 8 parts of water-based epoxy resin, 3 parts of water-based curing agent and 0.1 parts of defoaming agent into the empty asphalt mixing pot and stir for 60 seconds;

[0103] 4) Add the mixture obtained in step 2) to the asphalt mixing pot in step 3) and stir for 90 seconds; finally, add 10 parts of modified steel slag powder and continue stirring for 90 seconds to obtain a cold-mixed all-steel slag asphalt mixture.

[0104] Example 2:

[0105] The invention discloses a preparation method of a cold-mixed all-steel slag asphalt mixture. The raw materials include: coarse steel slag, fine steel slag, modified steel slag powder, triethanolamine, polydimethylsiloxane, fly ash, hydrogen peroxide, emulsified asphalt, water-based epoxy resin, water-based curing agent, and defoaming agent.

[0106] The crude steel slag has a particle size of 4.75-10mm, an abrasion value of ≤30%, and a crushing value of ≤22%, and is derived from electric furnace steel slag tailings.

[0107] Among them, the fine steel slag particle size is 0.075-4.75mm; it comes from electric furnace steel slag tailings;

[0108] Among them, the modified steel slag powder has a particle size of 0-0.075mm and comes from electric furnace steel slag tailings.

[0109] Furthermore, the preparation steps of the modified steel slag powder are: steel slag with a particle size of 0-0.30 mm, waste slurry powder with a particle size of 0-0.30 mm, and triethanolamine are uniformly mixed in a mass ratio of 90 parts:10 parts:2 parts, and then placed in a ball mill and ground for 10 hours until the obtained mixed powder has a fineness of 0.075 mm and a standard square hole sieve pass rate of more than 98%. The mixed powder is dried at 90°C for 2 hours to obtain the modified steel slag powder.

[0110] Among them, waste pulp particles are white mud at the bottom of the paper mill sedimentation tank, the main component of which is CaCO3, mixed with a small amount of pulping fiber. Before use, it must be dried and crushed to the required particle size;

[0111] Among them, triethanolamine is a colorless oily liquid, soluble in water, and has the function of aiding grinding;

[0112] Among them, polydimethylsiloxane is non-toxic, colorless and odorless, with a viscosity of about 25mPa.S, has the function of bonding and defoaming, and is industrial grade;

[0113] Among them, the fly ash is secondary fly ash with a specific surface area of ​​4900-5300 cm2 / g and a loss on ignition of 6.9-8.4%;

[0114] Among them, hydrogen peroxide was diluted with a dilution ratio of 1:65 as before;

[0115] The emulsified asphalt is one of cationic medium-cracking emulsified asphalt and cationic slow-cracking emulsified asphalt;

[0116] Among them, the water-based epoxy resin model is E-44, light yellow, and comes from a chemical company;

[0117] Among them, the water-based curing agent is Shuangfenghuang 593 type, which is colorless and transparent, with a viscosity of 125mPa.S, and comes from a chemical company;

[0118] The defoaming agent is one of sodium tetrapropylene benzene sulfonate and sodium lauryl sulfate.

[0119] According to the above, the method for preparing cold-mix all-steel slag asphalt mixture further comprises the following steps:

[0120] 1) Add 100 parts by mass of crude steel slag and 60 parts by mass of fine steel slag into an asphalt mixing pot and stir for 90 seconds;

[0121] 2) Then, 5 parts by mass of modified steel slag powder, 2 parts by mass of polydimethylsiloxane, 5 parts by mass of fly ash, and 1 part by mass of hydrogen peroxide were added to the stirring pot of step 1) and stirred for 90 seconds. The mixture was then poured out and air-dried for 30 minutes for later use;

[0122] 3) Add 6 parts of emulsified asphalt, 8 parts of water-based epoxy resin, 2 parts of water-based curing agent and 0.1 parts of defoaming agent into the empty asphalt mixing pot and stir for 60 seconds;

[0123] 4) Add the mixture obtained in step 2) to the asphalt mixing pot in step 3) and stir for 90 seconds; finally, add 10 parts of modified steel slag powder and continue stirring for 90 seconds to obtain a cold-mixed all-steel slag asphalt mixture.

[0124] Example 3:

[0125] The invention discloses a preparation method of a cold-mixed all-steel slag asphalt mixture. The raw materials include: coarse steel slag, fine steel slag, modified steel slag powder, triethanolamine, polydimethylsiloxane, fly ash, hydrogen peroxide, emulsified asphalt, water-based epoxy resin, water-based curing agent, and defoaming agent.

[0126] The crude steel slag has a particle size of 4.75-10mm, an abrasion value of ≤30%, and a crushing value of ≤22%, and is derived from electric furnace steel slag tailings.

[0127] Among them, the fine steel slag particle size is 0.075-4.75mm; it comes from electric furnace steel slag tailings;

[0128] Among them, the modified steel slag powder has a particle size of 0-0.075mm and comes from electric furnace steel slag tailings.

[0129] Furthermore, the preparation steps of the modified steel slag powder are: steel slag with a particle size of 0-0.30 mm, waste slurry powder with a particle size of 0-0.30 mm, and triethanolamine are uniformly mixed in a mass ratio of 85 parts:15 parts:2 parts, and then placed in a ball mill and ground for 10 hours until the obtained mixed powder has a fineness of 0.075 mm and a standard square hole sieve pass rate of more than 98%. The mixed powder is dried at 90°C for 2 hours to obtain the modified steel slag powder.

[0130] Among them, waste pulp particles are white mud at the bottom of the paper mill sedimentation tank, the main component of which is CaCO3, mixed with a small amount of pulping fiber. Before use, it must be dried and crushed to the required particle size;

[0131] Among them, triethanolamine is a colorless oily liquid, soluble in water, and has the function of aiding grinding;

[0132] Among them, polydimethylsiloxane is non-toxic, colorless and odorless, with a viscosity of about 25mPa.S, has the function of bonding and defoaming, and is industrial grade;

[0133] Among them, the fly ash is secondary fly ash with a specific surface area of ​​4900-5300 cm2 / g and a loss on ignition of 6.9-8.4%;

[0134] Among them, hydrogen peroxide was diluted with a dilution ratio of 1:65 as before;

[0135] The emulsified asphalt is one of cationic medium-cracking emulsified asphalt and cationic slow-cracking emulsified asphalt;

[0136] Among them, the water-based epoxy resin model is E-44, light yellow, and comes from a chemical company;

[0137] Among them, the water-based curing agent is Shuangfenghuang 593 type, which is colorless and transparent, with a viscosity of 125mPa.S, and comes from a chemical company;

[0138] The defoaming agent is one of sodium tetrapropylene benzene sulfonate and sodium lauryl sulfate.

[0139] According to the above, the method for preparing cold-mix all-steel slag asphalt mixture further comprises the following steps:

[0140] 1) Add 100 parts by mass of crude steel slag and 50 parts by mass of fine steel slag into an asphalt mixing pot and stir for 60 seconds;

[0141] 2) Then, 4 parts by mass of modified steel slag powder, 2 parts by mass of polydimethylsiloxane, 5 parts by mass of fly ash, and 1.5 parts by mass of hydrogen peroxide were added to the stirring pot in step 1) and stirred for 90 seconds. The mixture was then poured out and air-dried for 30 minutes for later use;

[0142] 3) Add 6 parts of emulsified asphalt, 12 parts of water-based epoxy resin, 6 parts of water-based curing agent and 0.5 parts of defoaming agent into the empty asphalt mixing pot and stir for 60 seconds;

[0143] 4) Add the mixture obtained in step 2) to the asphalt mixing pot in step 3) and stir for 90 seconds; finally, add 8 parts of modified steel slag powder and continue stirring for 90 seconds to obtain a cold-mixed all-steel slag asphalt mixture.

[0144] Example 4:

[0145] The invention discloses a preparation method of a cold-mixed all-steel slag asphalt mixture. The raw materials include: coarse steel slag, fine steel slag, modified steel slag powder, triethanolamine, polydimethylsiloxane, fly ash, hydrogen peroxide, emulsified asphalt, water-based epoxy resin, water-based curing agent, and defoaming agent.

[0146] The crude steel slag has a particle size of 4.75-10mm, an abrasion value of ≤30%, and a crushing value of ≤22%, and is derived from electric furnace steel slag tailings.

[0147] Among them, the fine steel slag particle size is 0.075-4.75mm; it comes from electric furnace steel slag tailings;

[0148] Among them, the modified steel slag powder has a particle size of 0-0.075mm and comes from electric furnace steel slag tailings.

[0149] Furthermore, the modified steel slag powder is prepared by uniformly mixing steel slag with a particle size of 0-0.30 mm, waste slurry powder with a particle size of 0-0.30 mm, and triethanolamine in a mass ratio of 85 parts:15 parts:1 part, then grinding in a ball mill for 9 hours until the obtained mixed powder has a fineness of 0.075 mm and a pass rate of 98% or more through a standard square hole sieve, and drying the mixed powder at 90° C. for 2 hours to obtain the modified steel slag powder;

[0150] Among them, waste pulp particles are white mud at the bottom of the paper mill sedimentation tank, the main component of which is CaCO3, mixed with a small amount of pulping fiber. Before use, it must be dried and crushed to the required particle size;

[0151] Among them, triethanolamine is a colorless oily liquid, soluble in water, and has the function of aiding grinding;

[0152] Among them, polydimethylsiloxane is non-toxic, colorless and odorless, with a viscosity of about 25mPa.S, has the function of bonding and defoaming, and is industrial grade;

[0153] Among them, the fly ash is secondary fly ash with a specific surface area of ​​4900-5300 cm2 / g and a loss on ignition of 6.9-8.4%;

[0154] Among them, hydrogen peroxide was diluted with a dilution ratio of 1:65 as before;

[0155] The emulsified asphalt is one of cationic medium-cracking emulsified asphalt and cationic slow-cracking emulsified asphalt;

[0156] Among them, the water-based epoxy resin model is E-44, light yellow, and comes from a chemical company;

[0157] Among them, the water-based curing agent is Shuangfenghuang 593 type, which is colorless and transparent, with a viscosity of 125mPa.S, and comes from a chemical company;

[0158] The defoaming agent is one of sodium tetrapropylene benzene sulfonate and sodium lauryl sulfate.

[0159] According to the above, the method for preparing cold-mix all-steel slag asphalt mixture further comprises the following steps:

[0160] 1) Add 100 parts by mass of crude steel slag and 60 parts by mass of fine steel slag into an asphalt mixing pot and stir for 90 seconds;

[0161] 2) Then, 5 parts by mass of modified steel slag powder, 2 parts by mass of polydimethylsiloxane, 3 parts by mass of fly ash, and 1 part by mass of hydrogen peroxide were added to the stirring pot of step 1) and stirred for 90 seconds. The mixture was then poured out and air-dried for 30 minutes for later use;

[0162] 3) Add 6 parts of emulsified asphalt, 10 parts of water-based epoxy resin, 6 parts of water-based curing agent and 0.3 parts of defoaming agent into the empty asphalt mixing pot and stir for 60 seconds;

[0163] 4) Add the mixture obtained in step 2) to the asphalt mixing pot in step 3) and stir for 60 seconds; finally, add 8 parts of modified steel slag powder and continue stirring for 90 seconds to obtain a cold-mixed all-steel slag asphalt mixture.

[0164] Example 5:

[0165] The invention discloses a preparation method of a cold-mixed all-steel slag asphalt mixture. The raw materials include: coarse steel slag, fine steel slag, modified steel slag powder, triethanolamine, polydimethylsiloxane, fly ash, hydrogen peroxide, emulsified asphalt, water-based epoxy resin, water-based curing agent, and defoaming agent.

[0166] The crude steel slag has a particle size of 4.75-10mm, an abrasion value of ≤30%, and a crushing value of ≤22%, and is derived from electric furnace steel slag tailings.

[0167] Among them, the fine steel slag particle size is 0.075-4.75mm; it comes from electric furnace steel slag tailings;

[0168] Among them, the modified steel slag powder has a particle size of 0-0.075mm and comes from electric furnace steel slag tailings;

[0169] Furthermore, the preparation steps of the modified steel slag powder are: steel slag with a particle size of 0-0.30 mm, waste slurry powder with a particle size of 0-0.30 mm, and triethanolamine are uniformly mixed in a mass ratio of 80 parts: 15 parts: 1.5 parts, and then placed in a ball mill and ground for 10 hours until the obtained mixed powder has a fineness of 0.075 mm and a standard square hole sieve pass rate of more than 98%. The mixed powder is dried at 90°C for 1.5 hours to obtain the modified steel slag powder.

[0170] Among them, waste pulp particles are white mud at the bottom of the paper mill sedimentation tank, the main component of which is CaCO3, mixed with a small amount of pulping fiber. Before use, it must be dried and crushed to the required particle size;

[0171] Among them, triethanolamine is a colorless oily liquid, soluble in water, and has the function of aiding grinding;

[0172] Among them, polydimethylsiloxane is non-toxic, colorless and odorless, with a viscosity of about 25mPa.S, has the function of bonding and defoaming, and is industrial grade;

[0173] Among them, the fly ash is secondary fly ash with a specific surface area of ​​4900-5300 cm2 / g and a loss on ignition of 6.9-8.4%;

[0174] Among them, hydrogen peroxide was diluted with a dilution ratio of 1:65 as before;

[0175] The emulsified asphalt is one of cationic medium-cracking emulsified asphalt and cationic slow-cracking emulsified asphalt;

[0176] Among them, the water-based epoxy resin model is E-44, light yellow, and comes from a chemical company;

[0177] Among them, the water-based curing agent is Shuangfenghuang 593 type, which is colorless and transparent, with a viscosity of 125mPa.S, and comes from a chemical company;

[0178] The defoaming agent is one of sodium tetrapropylene benzene sulfonate and sodium lauryl sulfate.

[0179] According to the above, the method for preparing cold-mix all-steel slag asphalt mixture further comprises the following steps:

[0180] 1) Add 100 parts by mass of crude steel slag and 55 parts by mass of fine steel slag into an asphalt mixing pot and stir for 80 seconds;

[0181] 2) Then, 4 parts by mass of modified steel slag powder, 1.5 parts by mass of polydimethylsiloxane, 4 parts by mass of fly ash, and 1.2 parts by mass of hydrogen peroxide were added to the stirring pot in step 1) and stirred for 80 seconds. The mixture was then poured out and air-dried for 30 minutes for later use;

[0182] 3) Add 4 parts of emulsified asphalt, 9 parts of water-based epoxy resin, 3 parts of water-based curing agent and 0.5 parts of defoaming agent into the empty asphalt mixing pot and stir for 60 seconds;

[0183] 4) Add the mixture obtained in step 2) to the asphalt mixing pot in step 3) and stir for 80 seconds; finally, add 10 parts of modified steel slag powder and continue stirring for 80 seconds to obtain a cold-mixed all-steel slag asphalt mixture.

[0184] The performance tests of various parameters of the cold-mixed all-steel slag asphalt mixtures prepared in Examples 1 to 5 refer to the following standards, and the parameter values ​​are shown in Table 1:

[0185] Rutting test, measuring dynamic stability at 60°C and 70°C: "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" JTG·E20-2011 (T0719-2011);

[0186] Water stability test, testing the water-immersion Marshall residual stability and freeze-thaw splitting strength ratio: "Test Procedure for Asphalt and Asphalt Mixtures for Highway Engineering" JTG·E20-2011 (T0709-2011, T0729-2000);

[0187] Low-temperature bending test, testing the ultimate bending strain at -10°C: "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG·E20-2011 (T 0715-2011);

[0188] Shear strength: The uniaxial penetration test conducted by Bi Yufeng of Tongji University was used. Test conditions: ① Specimen shape: Φ100mm×100mm; ② Test temperature: 60℃, holding temperature for 6h; ③ Loading rate: 1mm / min;

[0189] Expansiveness: Tested with reference to the experimental method in the master's thesis of Wuhan University of Technology "Preparation and Performance Research of Steel Slag Asphalt Mastic Mixture".

[0190] Table 1, performance test of embodiment:

[0191] Performance parameters Example 1 Example 2 Example 3 Example 4 Example 5 60℃ dynamic stability (times / mm) 7250 7620 7845 7960 8250 70℃ dynamic stability (times / mm) 5230 5500 5786 5860 6012 Marshall residual stability after immersion in water 91.2 91.5 92.2 91.7 91.6 Freeze-thaw splitting strength ratio (%) 89.2 89.5 90.2 89.6 90.5 -10℃ bending strain (μξ) 2452 2563 2580 2563 2604 Shear strength (MPa) 1.05 1.12 1.26 1.34 1.40 Expansion (%) 0.82 0.80 0.78 0.74 0.72

[0192] The raw materials listed in the present invention, as well as the upper and lower limits, interval values ​​of the raw materials, and the upper and lower limits of the process parameters can all realize the present invention.

[0193] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing modified steel slag powder for cold-mixed all-steel slag asphalt mixture, characterized in that: The method comprises the following preparation steps: 1) Place 80-90 parts of steel slag, 10-20 parts of waste pulp powder and 1-2 parts of triethanolamine in a mixing drum and stir to form a mixture; 2) Grinding the mixed material in a ball mill for a set time to form a powder; 3) The powder is placed in a dryer for drying to obtain modified steel slag powder.

2. The method for preparing modified steel slag powder for cold mix all-steel slag asphalt mixture according to claim 1, characterized in that: In the preparation step 1), the particle size of the steel slag is between 0.1 mm and 0.3 mm.

3. The method for preparing modified steel slag powder for cold mix all-steel slag asphalt mixture according to claim 1, characterized in that: In the preparation step 2), the mixed material is ground in a ball mill for 8 to 10 hours to form the powder.

4. The method for preparing modified steel slag powder for cold mix all-steel slag asphalt mixture according to claim 1, wherein: In the preparation step 2), the powder has a fineness of 0.075 mm and a passing rate of 98% or more through a standard square hole sieve.

5. The method for preparing modified steel slag powder for cold mix all-steel slag asphalt mixture according to claim 1, characterized in that: In the preparation step 3), the dryer has a drying chamber, the drying temperature of the drying chamber is between 90° C. and 100° C., and the powder is placed in the drying chamber and dried for a set time to obtain the modified steel slag powder.

6. The method for preparing modified steel slag powder for cold mix all-steel slag asphalt mixture according to claim 1, characterized in that: In the preparation step 3), the powder is dried in a drying chamber for 1 to 2 hours to form modified steel slag powder.

7. The method for preparing modified steel slag powder for cold-mixed all-steel slag asphalt mixture according to claim 1, wherein: In the preparation step 1), the waste pulp powder particles are white mud at the bottom of the sedimentation tank of the paper mill, and the waste pulp powder particles contain calcium carbonate and pulping fibers.

8. The method for preparing modified steel slag powder for cold mix all-steel slag asphalt mixture according to claim 1, characterized in that: In the preparation step 1), the waste pulp particles are placed in the mixing drum, dried and crushed in sequence, and the crushed waste pulp particles are placed in the mixing drum.

9. The method for preparing modified steel slag powder for cold mix all-steel slag asphalt mixture according to any one of claims 1 to 8, characterized in that: In the preparation step 3), the dryer comprises a longitudinally arranged drying chamber, wherein a plurality of powder filter plates are provided in the drying chamber, each of the powder filter plates having a plurality of powder filter holes; the plurality of powder filter plates are sequentially spaced along the height direction of the drying chamber to divide the drying chamber into a plurality of drying sections, and the plurality of drying sections are sequentially connected and arranged from top to bottom; In the preparation step 3), after the drying chamber is heated to a set temperature, the air in the drying chamber becomes hot air; the powder is placed on the top of the drying chamber, and the powder falls from top to bottom in sequence, passes through multiple powder filter plates, and falls to the bottom of the drying chamber. The hot air in the drying chamber dries the powder that falls in the drying section.

10. The method for preparing modified steel slag powder for cold-mixed all-steel slag asphalt mixture according to claim 9, characterized in that: The bottom of the drying chamber is covered with an elastic film layer, the outer periphery of the elastic film layer is fixedly arranged, and the middle portion of the elastic film layer is freely arranged, and an air-filled space is formed between the elastic film layer and the bottom of the drying chamber; When the powder passes through the plurality of powder filter plates in sequence from top to bottom in the drying chamber, the air is inflated or inhaled into the air space by the air inflating and inhaling device, driving the elastic membrane layer to elastically bulge and deform back and forth, and the elastic membrane layer disturbs the falling powder.

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