Environment-friendly cement based on carbonaceous coal gangue and method for manufacturing the same
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGAN UNIV
- Filing Date
- 2024-11-12
- Publication Date
- 2026-06-23
Smart Images
Figure BDA0005130965700000071
Abstract
Description
Technical Field
[0001] This application relates to the field of cement, and more specifically, to an environmentally friendly cement based on carbonaceous coal gangue and a method for manufacturing the same. Background Technology
[0002] Coal gangue is a solid waste generated during coal mining and washing. It is a dark gray rock with a low carbon content and harder than coal, which is associated with coal seams during coal formation. It mainly includes gangue from tunnel excavation, gangue extracted from the roof, floor, and interlayers during mining, and gangue removed during coal washing. The main components of coal gangue are Al2O3 and SiO2, and it also contains varying amounts of Fe2O3, CaO, MgO, Na2O, K2O, P2O5, SO3, and trace amounts of rare elements (gallium, vanadium, titanium, cobalt).
[0003] In related technologies, the harmless treatment of coal gangue is mainly for its use as roadbed filling, thereby improving the stability and load-bearing capacity of the roadbed. However, the above-mentioned treatment scheme is essentially still a matter of stockpiling coal gangue, and it still does not effectively utilize the active substances in the coal gangue. Furthermore, harmful substances such as heavy metals and sulfides in coal gangue may seep into the ground, polluting groundwater and soil, and causing damage to the ecological environment. Summary of the Invention
[0004] To facilitate the rational and efficient utilization of coal gangue, this application provides an environmentally friendly cement based on carbonaceous coal gangue and its manufacturing method.
[0005] This application provides an environmentally friendly cement based on carbonaceous coal gangue, employing the following technical solution:
[0006] Environmentally friendly cement based on carbonaceous coal gangue comprises the following raw materials in parts by weight:
[0007] 60-80 parts of modified coal gangue powder;
[0008] 30-40 parts cement clinker;
[0009] 10-20 parts of slag powder;
[0010] 10-15 parts of desulfurized gypsum;
[0011] 5-10 parts tourmaline powder;
[0012] 5-10 parts of ammonium sulfate powder;
[0013] 3-7 parts sodium carboxymethyl cellulose;
[0014] The modified coal gangue powder is obtained by calcining and activating coal gangue powder and then enhancing it with β-alanine aqueous solution.
[0015] By adopting the above technical solutions, modified coal gangue powder and cement clinker are used as the main cementitious materials. The synergistic effect of modified coal gangue powder and cement clinker ensures that the cement has good cementitious properties and strength. Slag powder, as a filler material, can improve the density of the cementitious material. Desulfurized gypsum is used to regulate the setting time of the cement, so that the cement clinker can fully undergo the hydration reaction and exert its cementitious effect. The addition of ammonium sulfate powder helps to improve the early strength of the cement, thus maintaining good workability. The purpose of adding tourmaline powder is to utilize its good thermoelectric effect. When cement hydration releases heat, tourmaline powder generates a large number of negative ions due to temperature changes. The negative ions migrate between the slurry, which can promptly remove the heat inside the slurry, thereby reducing the heat of hydration inside the slurry and ensuring uniform temperature inside the cement slurry, thus improving the problem of easy cracking during the cement hardening process. The addition of sodium carboxymethyl cellulose can improve the consistency of the slurry, giving it better water retention properties, thereby improving the workability of cement concrete. This application uses coal gangue as one of the main raw materials and transforms it into high-value-added environmentally friendly cement through activation and enhancement treatment. This not only reduces dependence on natural resources but also realizes the reuse of waste resources and improves resource utilization.
[0016] Optionally, the modified coal gangue powder is obtained by the following method:
[0017] S1. Activated coal gangue powder is obtained by calcining coal gangue powder at 600-650℃ for 2-2.5h.
[0018] S2. Mix activated coal gangue powder with β-alanine aqueous solution, wherein the mass ratio of activated coal gangue powder to β-alanine is 1:3-5. Stir and react for 2-2.5 hours. After the reaction is completed, filter the mixture, dry the filter residue, and ball mill it to obtain modified coal gangue powder.
[0019] By employing the above technical solution, calcining coal gangue powder at a high temperature of 600-650℃ can induce thermal decomposition and lattice reconstruction, increasing surface active sites and enhancing reactivity. β-Alanine can chemically react with the functional groups on the surface of activated coal gangue powder, improving its surface properties and increasing its compatibility and binding capacity with other cement components. Filtration and drying steps can remove unreacted β-alanine and other impurities, ensuring the purity and quality of the modified coal gangue powder. Cement prepared using the above method, when uniformly mixed with cement clinker, exhibits excellent cementitious properties and mechanical properties.
[0020] Optionally, the mass concentration of the β-alanine aqueous solution in S2 is 12-15%.
[0021] By employing the above technical solution, the mass concentration of the β-alanine aqueous solution directly affects the surface activity and reaction characteristics of activated coal gangue powder. When the concentration is too low, the reaction is incomplete, potentially leading to poor modification; when the concentration is too high, it may result in waste and increase production costs. Therefore, selecting an appropriate concentration of the β-alanine aqueous solution can reduce production costs and improve product quality while ensuring the reaction effect.
[0022] Optionally, the tourmaline powder is preferably magnesium tourmaline powder.
[0023] By adopting the above technical solution, magnesium tourmaline powder has a more significant thermoelectric effect due to the presence of metal ions, thus having a better heat conduction effect and reducing the problem of cement cracking caused by the heat release of cement hydration.
[0024] Optionally, the particle size of the magnesium tourmaline powder is 100-300 mesh.
[0025] Optionally, the ammonium sulfate powder has a particle size of 100-300 mesh.
[0026] By adopting the above technical solution, the particle size of tourmaline powder and ammonium sulfate powder can be controlled within the above range, which helps to improve the reactivity and mixing uniformity of the materials, thereby improving the performance of cement.
[0027] Optionally, the raw material may also include 3-5 parts of methacryloxysilane.
[0028] By adopting the above technical solution, the addition of silane coupling agents such as methacryloxysilane, which contain unsaturated double bonds, can react with the hydroxyl groups on the surface of tourmaline powder to form stable chemical bonds, thereby enhancing the interfacial bonding force between tourmaline powder and cement matrix. This makes the internal particles of cement more tightly bonded together, reducing internal microcracks and pores, and thus improving the overall strength of cement.
[0029] Secondly, this application provides a method for manufacturing environmentally friendly cement based on carbonaceous coal gangue, employing the following technical solution:
[0030] The method for manufacturing environmentally friendly cement based on carbonaceous coal gangue includes the following steps:
[0031] (1) Batching: Weigh each raw material according to the proportion, and put all raw materials except cement clinker into a mixer to mix them evenly.
[0032] (2) Add water: Add 150-200 parts of water to the mixer and continue mixing to form a uniform slurry;
[0033] (3) Drying: The slurry is dried at a temperature of 60-80℃ for 24-48 hours. After the dried slurry is ball-milled, it is mixed evenly with cement clinker and then packaged to obtain the finished product.
[0034] By adopting the above technical solution, the production process of this environmentally friendly cement is simple, the production cost is low, and it has good economic benefits. At the same time, it can make efficient and rational use of solid waste resources such as coal gangue and slag, effectively reducing the damage to the ecological environment caused by bulk solid waste.
[0035] In summary, this application has the following beneficial effects:
[0036] 1. Because this application uses modified coal gangue powder and cement clinker as the main cementitious materials, the synergistic effect of modified coal gangue powder and cement clinker can ensure that the cement has good cementitious properties and strength performance. Coal gangue is used as one of the main raw materials and, through activation and strengthening treatment, is transformed into high-value-added environmentally friendly cement. This not only reduces dependence on natural resources but also realizes the reuse of waste resources, improving resource utilization. By adding tourmaline powder, which has a good thermoelectric effect, when cement hydration releases heat, the tourmaline powder generates a large number of negative ions due to temperature changes. These negative ions displace freely between the slurry particles, allowing the heat inside the slurry to be transferred and carried away in a timely manner, thereby reducing the heat of hydration inside the slurry and promoting uniform temperature inside the cement slurry, thus improving the problem of easy cracking during cement hardening.
[0037] 2. In this application, coal gangue powder is activated at high temperature, followed by surface treatment with an aqueous solution of β-alanine. Calcination of the coal gangue powder at 600-650℃ induces thermal decomposition and lattice reconstruction, increasing surface active sites and enhancing reactivity. β-alanine reacts chemically with functional groups on the surface of the activated coal gangue powder to form chemical bonds, thereby improving the surface properties of the coal gangue powder. This increases its compatibility and bonding ability with other cement components, ultimately improving the cementitious properties and strength of the cement.
[0038] 3. The method of this application has a simple production process, low production cost, and good economic benefits. At the same time, it can make efficient and rational use of solid waste resources such as coal gangue and slag, effectively reducing the damage to the ecological environment caused by large-scale solid waste. Detailed Implementation
[0039] The present application will be further described in detail below with reference to the embodiments.
[0040] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.
[0041] The coal gangue powder selected in this application has a loose bulk density of 1200-1400 kg / m3 and a crushing value of 10.0%; the cement clinker for 52.5 grade PI type silicate cement was purchased from Shandong Sanyi New Materials Co., Ltd.; the slag powder was purchased from Lingshou County Zhanxing Mineral Products Co., Ltd., item number 8828; the desulfurization gypsum was purchased from Zaozhuang Xinghao New Materials Co., Ltd., model 653; and the magnesium tourmaline powder was purchased from Lingshou County Yuanda Mica Factory, item number 0067-16.
[0042] Preparation example of modified coal gangue powder
[0043] Preparation Example 1
[0044] S1. Activated coal gangue powder is obtained by calcining coal gangue powder at 600℃ for 2.5h.
[0045] S2. Dissolve 30 kg of β-alanine in water to prepare a 12% β-alanine aqueous solution. Mix the solution with 10 kg of activated coal gangue powder and stir for 2 hours. After the reaction is complete, filter the solution and dry and ball-mill the filter residue to obtain modified coal gangue powder.
[0046] Preparation Example 2
[0047] S1. Activated coal gangue powder is obtained by calcining coal gangue powder at 630℃ for 2.5h.
[0048] S2. Dissolve 40 kg of β-alanine in water to prepare a 13% β-alanine aqueous solution. Mix the solution with 10 kg of activated coal gangue powder and stir for 2.5 h. After the reaction is complete, filter the solution and dry and ball-mill the filter residue to obtain modified coal gangue powder.
[0049] Preparation Example 3
[0050] S1. Activated coal gangue powder is obtained by calcining coal gangue powder at 650℃ for 2.5h.
[0051] S2. Dissolve 50 kg of β-alanine in water to prepare a 15% β-alanine aqueous solution. Mix the solution with 10 kg of activated coal gangue powder and stir for 2.5 h. After the reaction is complete, filter the solution and dry and ball-mill the filter residue to obtain modified coal gangue powder.
[0052] Preparation Example 4
[0053] S1. Activated coal gangue powder is obtained by calcining coal gangue powder at 650℃ for 2.5h.
[0054] S2. Dissolve 50 kg of β-alanine in water to prepare a β-alanine aqueous solution with a mass concentration of 30%. Mix the solution with 10 kg of activated coal gangue powder and stir for 2.5 h. After the reaction is completed, filter the solution, dry the filter residue, and ball mill it to obtain modified coal gangue powder.
[0055] Preparation Example 5
[0056] S1. Activated coal gangue powder is obtained by calcining coal gangue powder at 650℃ for 2.5h.
[0057] S2. Dissolve 50 kg of β-alanine in water to prepare a 5% β-alanine aqueous solution. Mix the solution with 10 kg of activated coal gangue powder and stir for 2.5 h. After the reaction is complete, filter the solution and dry and ball-mill the filter residue to obtain modified coal gangue powder.
[0058] Example
[0059] Example 1
[0060] The environmentally friendly cement based on carbonaceous coal gangue has the following raw material components and dosages as shown in Table 1. The modified coal gangue powder is the modified coal gangue powder prepared in Preparation Example 1, the tourmaline powder is magnesium tourmaline powder with a particle size of 100 mesh, and the ammonium sulfate powder has a particle size of 100 mesh.
[0061] Environmentally friendly cement based on carbonaceous coal gangue is prepared using the following method:
[0062] (1) Batching: Weigh each raw material according to the proportion, and put all raw materials except cement clinker into a mixer to mix them evenly.
[0063] (2) Add water: Add 150kg of water to the mixer and continue mixing to form a uniform slurry;
[0064] (3) Drying: The slurry is dried at a temperature of 60°C for 48 hours. After the dried slurry is ball-milled, it is mixed evenly with cement clinker and then packaged to obtain the finished product.
[0065] Example 2
[0066] The environmentally friendly cement based on carbonaceous coal gangue has the following raw material components and dosages as shown in Table 1. The modified coal gangue powder is the modified coal gangue powder prepared in Preparation Example 2, the tourmaline powder is magnesium tourmaline powder with a particle size of 200 mesh, and the ammonium sulfate powder has a particle size of 200 mesh.
[0067] Environmentally friendly cement based on carbonaceous coal gangue is prepared using the following method:
[0068] (1) Batching: Weigh each raw material according to the proportion, and put all raw materials except cement clinker into a mixer to mix them evenly.
[0069] (2) Add water: Add 170 kg of water to the mixer and continue mixing to form a uniform slurry;
[0070] (3) Drying: The slurry is dried at a temperature of 70°C for 36 hours. After the dried slurry is ball-milled, it is mixed evenly with cement clinker and then packaged to obtain the finished product.
[0071] Example 3
[0072] The environmentally friendly cement based on carbonaceous coal gangue has the following raw material components and dosages as shown in Table 1. The modified coal gangue powder is the modified coal gangue powder prepared in Preparation Example 3, the tourmaline powder is magnesium tourmaline powder with a particle size of 300 mesh, and the ammonium sulfate powder has a particle size of 300 mesh.
[0073] Environmentally friendly cement based on carbonaceous coal gangue is prepared using the following method:
[0074] (1) Batching: Weigh each raw material according to the proportion, and put all raw materials except cement clinker into a mixer to mix them evenly.
[0075] (2) Add water: Add 200 kg of water to the mixer and continue mixing to form a uniform slurry;
[0076] (3) Drying: The slurry is dried at a temperature of 80°C for 24 hours. After the dried slurry is ball-milled, it is mixed evenly with cement clinker and then packaged to obtain the finished product.
[0077] Table 1. Raw material components and dosage (kg) of cement in Examples 1-3
[0078] Example 1 Example 2 Example 3 Modified coal gangue powder 60 70 80 cement clinker 40 30 20 Slag powder 10 15 20 Desulfurized gypsum 10 13 15 Magnesium tourmaline powder 5 8 10 Ammonium sulfate powder 5 7 10 Sodium hydroxymethylcellulose 3 5 7
[0079] Example 4
[0080] The environmentally friendly cement based on carbonaceous coal gangue differs from Example 3 in that the modified coal gangue powder used in this example is the modified coal gangue powder prepared in Preparation Example 4.
[0081] Example 5
[0082] The environmentally friendly cement based on carbonaceous coal gangue differs from Example 3 in that the modified coal gangue powder used in this example is the modified coal gangue powder prepared in Preparation Example 5.
[0083] Example 6
[0084] The environmentally friendly cement based on carbonaceous coal gangue differs from Example 3 in that lithium tourmaline powder is used as the raw material in this example.
[0085] Example 7
[0086] The environmentally friendly cement based on carbonaceous coal gangue differs from Example 3 in that 3 kg of methacryloyloxypropyltrimethoxysilane is added to the raw materials in this example.
[0087] Example 8
[0088] The environmentally friendly cement based on carbonaceous coal gangue differs from Example 3 in that 5 kg of methacryloyloxypropyltrimethoxysilane is added to the raw materials in this example.
[0089] Comparative Example
[0090] Comparative Example 1
[0091] The environmentally friendly cement based on carbonaceous coal gangue differs from Example 3 in that an equal amount of cement clinker is used instead of modified coal gangue powder in this comparative example.
[0092] Comparative Example 2
[0093] The environmentally friendly cement based on carbonaceous coal gangue differs from Example 3 in that an equal amount of unmodified coal gangue powder is used instead of modified coal gangue powder in the raw materials of this comparative example.
[0094] Comparative Example 3
[0095] The environmentally friendly cement based on carbonaceous coal gangue differs from Example 3 in that an equal amount of cement clinker is used instead of magnesium tourmaline powder in the raw materials of this comparative example.
[0096] Performance testing
[0097] Detection methods / test methods
[0098] The cements prepared in Examples 1-8 and Comparative Examples 1-3 were used as test samples. The standard consistency water requirement, setting time, and soundness were determined according to GB / T1346-2001. The mortar strength was determined according to GB / T17671-1999. The results are shown in Table 2.
[0099] Table 2 shows the test results of Examples 1-6 and Comparative Examples 1-4.
[0100]
[0101] As can be seen from Examples 1-3 and Comparative Example 1 and Table 2, in this example, modified coal gangue was used to replace part of the cement clinker. The cement prepared in this way had qualified stability and the setting time met the cement design requirements. Moreover, compared with cement that used cement clinker completely, its flexural strength and compressive strength were well maintained. Therefore, the modified coal gangue powder of this application can play a better role in cementitious properties and strength performance.
[0102] As can be seen from Examples 3-5 and Table 2, the concentration of the β-alanine aqueous solution during the preparation of modified coal gangue has a significant impact on the performance of the modified coal gangue powder, and thus has a significant impact on the compressive strength of cement. The β-alanine aqueous solution with a mass concentration of 12-15% provided in this application can maintain good compressive strength of cement after modifying coal gangue powder.
[0103] As can be seen from Examples 3 and 7-8 and Table 2, the addition of methacryloyloxysilanes to the raw materials can react with the hydroxyl groups on the surface of tourmaline powder to form stable chemical bonds, thereby improving the interfacial bonding force between tourmaline powder and cement matrix, and thus improving the overall strength of cement.
[0104] Combining Examples 3 and 6, and referring to Table 2, it can be seen that the compressive strength of the cement prepared by using lithium tourmaline powder as a raw material is lower than that of magnesium tourmaline powder.
[0105] Based on Example 3 and Comparative Example 2, and referring to Table 2, it can be seen that the cement mortar prepared using unmodified coal gangue powder showed varying degrees of strength loss compared to that prepared using modified coal gangue powder. This indicates that modified coal gangue has a good promoting effect on maintaining cement performance.
[0106] Combining Example 3 and Comparative Example 3, and referring to Table 2, it can be seen that in Comparative Example 3, since magnesium tourmaline powder was not used, the flexural strength of the cement mortar prepared was not significantly reduced, but the compressive strength was greatly affected, ultimately resulting in a significant loss in compressive strength.
[0107] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. An environmentally friendly cement based on carbonaceous coal gangue, characterized in that, The ingredients include the following parts by weight: 60-80 parts of modified coal gangue powder; 30-40 parts cement clinker; 10-20 parts of slag powder; 10-15 parts of desulfurized gypsum; 5-10 parts of magnesium tourmaline powder; 5-10 parts of ammonium sulfate powder; 3-7 parts sodium carboxymethyl cellulose; 3-5 parts of methacryloyloxysilanes; The modified coal gangue powder is obtained by the following method: S1. Activated coal gangue powder is obtained by calcining coal gangue powder at 600-650℃ for 2-2.5h. S2. Mix activated coal gangue powder with an aqueous solution of β-alanine, wherein the mass ratio of activated coal gangue powder to β-alanine is... The ratio is 1:3-5, the reaction is stirred for 2-2.5 hours, after the reaction is completed, the mixture is filtered, the filter residue is dried and ball-milled to obtain modified coal gangue powder; the mass concentration of the β-alanine aqueous solution in S2 is 12-15%.
2. The environmentally friendly cement based on carbonaceous coal gangue according to claim 1, characterized in that: The magnesium tourmaline powder The particle size is 100-300 mesh.
3. The environmentally friendly cement based on carbonaceous coal gangue according to claim 1, characterized in that: The ammonium sulfate powder The particle size is 100-300 mesh.
4. The method for manufacturing environmentally friendly cement based on carbonaceous coal gangue as described in any one of claims 1-3, characterized in that... The process includes the following steps: (1) Batching: Weigh each raw material according to the proportion, and put all raw materials except cement clinker into the mixer and mix them evenly; (2) Add water: Add 150-200 parts of water to the mixer and continue mixing to form a uniform slurry; (3) Drying: The slurry is dried at a temperature of 60-80℃ for 24-48 hours. After the dried slurry is ball-milled, it is mixed evenly with cement clinker and then packaged to obtain the finished product.