A preparation method of high-efficiency cement grinding aid

Abstract

The invention relates to the field of building materials, and more particularly to a method for preparing a high-efficiency cement grinding aid. The invention uses alkali lignin as a main raw material and improves its grinding aid and enhancement performance for cement clinker and mixed materials through chemical modification. The method of ammonium persulfate oxidation modification is adopted to reduce the relative molecular weight of the alkali lignin and increase the polar groups in the molecules to prepare the high-efficiency cement grinding aid. The grinding aid mechanism of the high-efficiency cement grinding aid prepared by the invention includes adsorption on the surface of new cement particles and charge shielding effects. Comprehensive performance measurements show that the high-efficiency cement grinding aid prepared by the invention has significantly better grinding aid performance than triethanolamine, and its effect on the later flexural and compressive strength of cement exceeds that of triethanolamine.

Description

Technical Field

[0001] The invention relates to the field of building materials, in particular to a method for preparing a high-efficiency cement grinding aid. Background Art

[0002] Cement grinding aids are a general term for chemical agents added to the system during the cement clinker grinding process. Primarily composed of surfactants, they adsorb onto the surfaces of solid particles during grinding, weakening the electrostatic repulsion, lowering the grinding surface energy, and reducing the tendency for fine particles to accumulate. This improves grinding efficiency, increases hourly output, and reduces grinding power consumption. With increasing demand for cement, the application of cement grinding aids is becoming increasingly widespread.

[0003] CN201110065852.5 discloses a modified alkali lignin and its preparation method. The cement grinding aid formulation, by weight, is: 200 parts alkali lignin, 10-20 parts oxidant, 10-20 parts activator, and 20-50 parts polar additive. The alkali lignin is acid-precipitated alkali lignin from bamboo or straw pulp papermaking black liquor, and has a solids content of 95% by weight. This preparation method uses alkali lignin as the primary raw material, adds an oxidant, an activator, and a polar additive, and produces a lignin-based, high-efficiency cement grinding aid through activation and oxidation reactions. The product, even at a low addition level of 0.1%, exhibits excellent grinding and strengthening properties for cement clinker and admixtures, with minimal impact on cement setting time. Its overall performance far surpasses that of conventional lignin sulfonate grinding aids, reaching the performance of triethanolamine grinding aids. The product, with its broad and inexpensive raw material source, simple process, and low production cost, is a new, green, and efficient cement grinding aid.

[0004] CN201310013199.7: Addressing the shortcomings of existing sodium lignin sulfonate and its synthesis methods as cement grinding aids in the prior art, a new method for preparing modified sodium lignin sulfonate is provided, and its application as a cement grinding aid has been shown to be effective. This method uses cellulose ethanol waste residue as raw material and obtains modified sodium lignin sulfonate through dissolution, sulfonation, and modification. The modified sodium lignin sulfonate obtained by the present invention has excellent grinding aid properties for cement at low addition levels. The product of the present invention is originally derived from discarded cellulose ethanol residue, which solves the problem of residue pollution. The production process is simple and feasible, and the product has better grinding aid effects as a cement aid than the prior art.

[0005] Although amine-based cement grinding aids are widely used and their performance is generally recognized by the market, their cost has been increasing with the rise in crude oil prices due to the fact that these products are derived from fossil raw materials. In order to reduce the cost of cement grinding aids, lignin derivatives have been widely used in the formulation of liquid cement grinding aids in recent years. The most widely used lignin derivatives are mainly lignin sulfonates, which are derived from acid-process papermaking wastewater. They include sodium, calcium, magnesium, and ammonium salts. They have complex sources, low sulfonic acid group content, and a wide range of relative molecular weight distribution. Due to the low adsorption capacity of lignin sulfonates on cement surfaces and the wide molecular weight distribution range, the molecular utilization efficiency of lignin sulfonates is low, and the adsorption coverage rate on the cement particle surface is also low. Therefore, these shortcomings of lignin sulfonates lead to their poor grinding performance in cement grinding, which also makes them difficult to promote and apply as high-performance cement grinding aids. Summary of the Invention

[0006] In a first aspect, the present invention provides a method for preparing a high-efficiency cement grinding aid, comprising:

[0007] According to weight, 180-200 parts of alkali lignin are weighed and mixed in water, sodium hydroxide is added to adjust the pH, then heated to 60-70°C and stirred to dissolve, 5-10 parts of dipropylene glycol are added, activation reaction is carried out at 60-70°C for 50-70 minutes, then the temperature is raised to 70-80°C, 2-5 parts of oxidant are added, and the reaction is carried out for 2-3 hours; finally, 10-20 parts of fatty alcohol additives are added, and the reaction is carried out at 70-80°C for 1.5-2 hours; after the reaction is completed, the mixture is cooled to room temperature to obtain a high-efficiency cement grinding aid.

[0008] As a further preferred embodiment of the present invention, the oxidant is potassium permanganate, ammonium persulfate or sodium hypochlorite.

[0009] As a further preferred embodiment of the present invention, the sodium hydroxide is used to adjust the pH to 11-12.

[0010] As a further preferred embodiment of the present invention, the fatty alcohol additive is C8-10 alcohol, C8-14 alcohol, C8-18 alcohol, C12-14 alcohol, C12-18 alcohol, or C14-16 alcohol.

[0011] Furthermore, a cerium-containing polyhydroxy oil-based polyacrylic acid polymer is provided to replace the fatty alcohol additive, and the preparation method thereof is as follows:

[0012] 0.03-0.2 parts of dioctadecylamine, 15-25 parts of oleylamine, 130-200 parts of N,N-dimethylethanolamine, 5-12 parts of polyhydroxy acrylate, 0.0005-0.002 parts of cerium methacrylate, and 3-7 parts of diethanolamine are added to a sealed reactor in parts by mass, nitrogen is introduced, and the mixture is stirred and reacted at 70-80°C for 1-3 hours. After the reaction is completed, 2-4 parts of benzoyl peroxide are added, and the mixture is reacted at 70-78°C for 60-180 minutes. The N,N-dimethylethanolamine is removed by distillation under reduced pressure to obtain a cerium-containing polyhydroxy oleyl polyacrylic acid polymer.

[0013] As a further preferred embodiment of the present invention, the polyhydroxy acrylate is at least one of U-1933R, U-1922, U-1908R, D-11, D-217, U-1907S, U-1906AD-5, U-845, U-2811S, U-2103, U-2108, U-2101N, U-2814-70, U-3100, and U-2815.

[0014] As a further preferred embodiment of the present invention, the polyhydroxy acrylate is at least one of U-1933R, D-11, U-845, U-2811S, and U-2103.

[0015] In a second aspect, the present invention provides a method for preparing cement, comprising:

[0016] According to weight, 150-200 parts of clinker and 5-10 parts of gypsum are weighed, crushed to a particle size of 1-2 cm, mixed evenly, added with 0.05-0.2 parts of a high-efficiency cement grinding aid, put into a grinder and grind for 10-20 minutes to obtain cement.

[0017] As a further preferred embodiment of the present invention, the compositions of the clinker are: 18-24% SiO2, 4.5-7.5% Al2O3, 3.2-4.8% Fe2O3, 62-74% CaO, 0.3-1.6% MgO, and 0.1-1.2% K2O.

[0018] Reaction mechanism:

[0019] Dioctadecylamine, oleylamine, polyhydroxy acrylate and cerium methacrylate are combined together through amino addition reaction to generate cerium-containing polyhydroxy oleyl polyacrylic acid polymer.

[0020] Technical effects:

[0021] The preparation method of a high-efficiency cement grinding aid of the present invention has the following technical effects compared with the prior art:

[0022] 1. The grinding aid effect of alkali lignin on cement increases with the decrease of its molecular weight. Oxidative degradation modification of alkali lignin can improve its grinding aid effect on cement. Alkali lignin oxidatively modified with ammonium persulfate has a better grinding aid effect.

[0023] 2. The high-efficiency cement grinding aid reinforced with cerium-containing polyhydroxy oil-based polyacrylic acid polymer prepared by the present invention has a significantly better effect on the late compressive strength of cement than triethanolamine;

[0024] 3. Oxidative modification increases the thickness of the adsorption layer of alkali lignin on the cement surface and improves the adsorption efficiency; after grinding, the high-efficiency cement grinding aid prepared by the present invention has a significantly increased density of high-energy active points but can exist stably, which is closely related to its adsorption on the surface of new particles and the charge shielding effect. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0026] Example 1

[0027] A method for preparing a high-efficiency cement grinding aid, comprising the following steps:

[0028] 180 kg of alkali lignin was weighed and mixed with water, sodium hydroxide was added to adjust the pH to 11, then heated to 60°C and stirred to dissolve, 5 kg of dipropylene glycol was added, and the activation reaction was carried out at 60°C for 50 minutes, then the temperature was raised to 70°C, 2 kg of oxidant was added, and the reaction was carried out for 2 hours; finally, 10 kg of fatty alcohol additive was added, and the reaction was carried out at 70°C for 1.5 hours; after the reaction was completed, it was cooled to room temperature to obtain a high-efficiency cement grinding aid.

[0029] The oxidant is potassium permanganate.

[0030] Provided is a cerium-containing polyhydroxy oil-based polyacrylic acid polymer to replace fatty alcohol additives, and its preparation method is as follows:

[0031] 0.03 kg of dioctadecylamine, 15 kg of oleylamine, 130 kg of N, N-dimethylethanolamine, 5 kg of polyhydroxy acrylate, 0.0005 kg of cerium methacrylate, and 3 kg of diethanolamine were added to a sealed reactor, nitrogen was introduced, and the mixture was stirred and reacted at 70°C for 1 hour. After the reaction was completed, 2 kg of benzoyl peroxide was added, and the mixture was reacted at 70°C for 60 minutes. N, N-dimethylethanolamine was removed by distillation under reduced pressure to obtain a cerium-containing polyhydroxy oil-based polyacrylic acid polymer.

[0032] The polyhydroxy acrylate is U-1933R.

[0033] 150 kg of clinker and 5 kg of gypsum were weighed, crushed to a particle size of 1 cm, mixed evenly, added with 0.05 kg of a high-efficiency cement grinding aid, and put into a grinder for grinding for 10 minutes to obtain cement.

[0034] The compositions of the clinker are: 22.10% SiO2, 5.27% Al2O3, 3.42% Fe2O3, 66.07% CaO, 1.39% MgO, and 0.70% K2O.

[0035] Example 2

[0036] A method for preparing a high-efficiency cement grinding aid, comprising the following steps:

[0037] 185 kg of alkali lignin was weighed and mixed with water, sodium hydroxide was added to adjust the pH to 11, then heated to 65 ° C and stirred to dissolve, 6 kg of dipropylene glycol was added, activated and reacted at 65 ° C for 55 minutes, then heated to 75 ° C, 3 kg of oxidant was added, and the reaction was continued for 2.5 hours; finally, 14 kg of fatty alcohol additive was added and the reaction was continued at 75 ° C for 1.5 hours; after the reaction was completed, it was cooled to room temperature to obtain a high-efficiency cement grinding aid.

[0038] The oxidant is ammonium persulfate.

[0039] Provided is a cerium-containing polyhydroxy oil-based polyacrylic acid polymer to replace fatty alcohol additives, and its preparation method is as follows:

[0040] 0.1 kg of dioctadecylamine, 18 kg of oleylamine, 150 kg of N, N-dimethylethanolamine, 7 kg of polyhydroxy acrylate, 0.001 kg of cerium methacrylate, and 4 kg of diethanolamine were added to a sealed reactor, nitrogen was introduced, and the mixture was stirred and reacted at 75°C for 2 hours. After the reaction was completed, 3 kg of benzoyl peroxide was added, and the mixture was reacted at 74°C for 90 minutes. N, N-dimethylethanolamine was removed by distillation under reduced pressure to obtain a cerium-containing polyhydroxy oil-based polyacrylic acid polymer.

[0041] The polyhydroxy acrylate is D-11.

[0042] 160 kg of clinker and 6 kg of gypsum were weighed, crushed to a particle size of 1 cm, mixed evenly, added with 0.1 kg of a high-efficiency cement grinding aid, and put into a grinder for grinding for 15 minutes to obtain cement.

[0043] The compositions of the clinker are: 22.10% SiO2, 5.27% Al2O3, 3.42% Fe2O3, 66.07% CaO, 1.39% MgO, and 0.70% K2O.

[0044] Example 3

[0045] A method for preparing a high-efficiency cement grinding aid, comprising the following steps:

[0046] 195 kg of alkali lignin was weighed and mixed with water, sodium hydroxide was added to adjust the pH to 12, then heated to 65 ° C and stirred to dissolve, 9 kg of dipropylene glycol was added, activated and reacted at 65 ° C for 65 minutes, then heated to 75 ° C, 4 kg of oxidant was added, and the reaction was continued for 2.5 hours; finally, 18 kg of fatty alcohol additive was added and the reaction was continued at 75 ° C for 2 hours; after the reaction was completed, it was cooled to room temperature to obtain a high-efficiency cement grinding aid.

[0047] The oxidant is ammonium persulfate.

[0048] Provided is a cerium-containing polyhydroxy oil-based polyacrylic acid polymer to replace fatty alcohol additives, and its preparation method is as follows:

[0049] 0.15 kg of dioctadecylamine, 22 kg of oleylamine, 180 kg of N, N-dimethylethanolamine, 10 kg of polyhydroxy acrylate, 0.0015 kg of cerium methacrylate, and 6 kg of diethanolamine were added to a sealed reactor, nitrogen was introduced, and the mixture was stirred and reacted at 75°C for 2 hours. After the reaction was completed, 3 kg of benzoyl peroxide was added, and the mixture was reacted at 75°C for 120 minutes. N, N-dimethylethanolamine was removed by distillation under reduced pressure to obtain a cerium-containing polyhydroxy oil-based polyacrylic acid polymer.

[0050] The polyhydroxy acrylate is U-845.

[0051] 180 kg of clinker and 9 kg of gypsum were weighed, crushed to a particle size of 2 cm, mixed evenly, added with 0.15 kg of a high-efficiency cement grinding aid, and put into a grinder for grinding for 15 minutes to obtain cement.

[0052] The compositions of the clinker are: 22.10% SiO2, 5.27% Al2O3, 3.42% Fe2O3, 66.07% CaO, 1.39% MgO, and 0.70% K2O.

[0053] Example 4

[0054] A method for preparing a high-efficiency cement grinding aid, comprising the following steps:

[0055] 200 kg of alkali lignin was weighed and mixed in water, sodium hydroxide was added to adjust the pH to 12, then heated to 70°C and stirred to dissolve, 10 kg of dipropylene glycol was added, and the activation reaction was carried out at 70°C for 70 minutes, then the temperature was raised to 80°C, 5 kg of oxidant was added, and the reaction was carried out for 3 hours; finally, 20 kg of fatty alcohol additive was added, and the reaction was carried out at 80°C for 2 hours; after the reaction was completed, it was cooled to room temperature to obtain a high-efficiency cement grinding aid.

[0056] The oxidant is sodium hypochlorite.

[0057] Provided is a cerium-containing polyhydroxy oil-based polyacrylic acid polymer to replace fatty alcohol additives, and its preparation method is as follows:

[0058] 0.2 kg of dioctadecylamine, 25 kg of oleylamine, 200 kg of N,N-dimethylethanolamine, 12 kg of polyhydroxy acrylate, 0.002 kg of cerium methacrylate, and 7 kg of diethanolamine were added to a sealed reactor, nitrogen was introduced, and the mixture was stirred and reacted at 80°C for 3 hours. After the reaction was completed, 4 kg of benzoyl peroxide was added, and the mixture was reacted at 78°C for 180 minutes. N,N-dimethylethanolamine was removed by distillation under reduced pressure to obtain a cerium-containing polyhydroxy oil-based polyacrylic acid polymer.

[0059] The polyhydroxy acrylate is U-2811S.

[0060] 200 kg of clinker and 10 kg of gypsum were weighed, crushed to a particle size of 2 cm, mixed evenly, added with 0.2 kg of a high-efficiency cement grinding aid, and put into a grinder for grinding for 20 minutes to obtain cement.

[0061] The compositions of the clinker are: 22.10% SiO2, 5.27% Al2O3, 3.42% Fe2O3, 66.07% CaO, 1.39% MgO, and 0.70% K2O.

[0062] Comparative Example 1

[0063] A method for preparing a high-efficiency cement grinding aid, comprising the following steps:

[0064] 180 kg of alkali lignin was weighed and mixed with water, sodium hydroxide was added to adjust the pH to 11, then heated to 60°C and stirred to dissolve, 5 kg of dipropylene glycol was added, and the reaction was activated at 60°C for 50 minutes, then the temperature was raised to 70°C, 2 kg of oxidant was added, and the reaction was carried out for 2 hours; after the reaction was completed, it was cooled to room temperature to obtain a high-efficiency cement grinding aid.

[0065] The oxidant is potassium permanganate.

[0066] 150 kg of clinker and 5 kg of gypsum were weighed, crushed to a particle size of 1 cm, mixed evenly, added with 0.05 kg of a high-efficiency cement grinding aid, and put into a grinder for grinding for 10 minutes to obtain cement.

[0067] The compositions of the clinker are: 22.10% SiO2, 5.27% Al2O3, 3.42% Fe2O3, 66.07% CaO, 1.39% MgO, and 0.70% K2O.

[0068] Comparative Example 2

[0069] A method for preparing a high-efficiency cement grinding aid, comprising the following steps:

[0070] 180 kg of alkali lignin was weighed and mixed with water, sodium hydroxide was added to adjust the pH to 11, then heated to 60°C and stirred to dissolve, 5 kg of dipropylene glycol was added, and the activation reaction was carried out at 60°C for 50 minutes, then the temperature was raised to 70°C, 2 kg of oxidant was added, and the reaction was carried out for 2 hours; finally, 10 kg of fatty alcohol additive was added, and the reaction was carried out at 70°C for 1.5 hours; after the reaction was completed, it was cooled to room temperature to obtain a high-efficiency cement grinding aid.

[0071] The oxidant is potassium permanganate.

[0072] Provided is a cerium-containing polyhydroxy oil-based polyacrylic acid polymer to replace fatty alcohol additives, and its preparation method is as follows:

[0073] 15 kg of oleylamine, 130 kg of N, N-dimethylethanolamine, 5 kg of polyhydroxy acrylate, 0.0005 kg of cerium methacrylate, and 3 kg of diethanolamine were added to a sealed reactor, nitrogen was introduced, and the mixture was stirred and reacted at 70° C. for 1 hour. After the reaction was completed, 2 kg of benzoyl peroxide was added, and the mixture was reacted at 70° C. for 60 minutes. N, N-dimethylethanolamine was removed by distillation under reduced pressure to obtain a cerium-containing polyhydroxy oleyl polyacrylic acid polymer.

[0074] The polyhydroxy acrylate is U-1933R.

[0075] 150 kg of clinker and 5 kg of gypsum were weighed, crushed to a particle size of 1 cm, mixed evenly, added with 0.05 kg of a high-efficiency cement grinding aid, and put into a grinder for grinding for 10 minutes to obtain cement.

[0076] The compositions of the clinker are: 22.10% SiO2, 5.27% Al2O3, 3.42% Fe2O3, 66.07% CaO, 1.39% MgO, and 0.70% K2O.

[0077] Comparative Example 3

[0078] A method for preparing a high-efficiency cement grinding aid, comprising the following steps:

[0079] 180 kg of alkali lignin was weighed and mixed with water, sodium hydroxide was added to adjust the pH to 11, then heated to 60°C and stirred to dissolve, 5 kg of dipropylene glycol was added, and the activation reaction was carried out at 60°C for 50 minutes, then the temperature was raised to 70°C, 2 kg of oxidant was added, and the reaction was carried out for 2 hours; finally, 10 kg of fatty alcohol additive was added, and the reaction was carried out at 70°C for 1.5 hours; after the reaction was completed, it was cooled to room temperature to obtain a high-efficiency cement grinding aid.

[0080] The oxidant is potassium permanganate.

[0081] Provided is a cerium-containing polyhydroxy oil-based polyacrylic acid polymer to replace fatty alcohol additives, and its preparation method is as follows:

[0082] 0.03 kg of dioctadecylamine, 15 kg of oleylamine, 130 kg of N, N-dimethylethanolamine, 0.0005 kg of cerium methacrylate, and 3 kg of diethanolamine were added to a sealed reactor, nitrogen was introduced, and the mixture was stirred and reacted at 70° C. for 1 hour. After the reaction was completed, 2 kg of benzoyl peroxide was added, and the mixture was reacted at 70° C. for 60 minutes. N, N-dimethylethanolamine was removed by distillation under reduced pressure to obtain a cerium-containing polyhydroxy oil-based polyacrylic acid polymer.

[0083] 150 kg of clinker and 5 kg of gypsum were weighed, crushed to a particle size of 1 cm, mixed evenly, added with 0.05 kg of a high-efficiency cement grinding aid, and put into a grinder for grinding for 10 minutes to obtain cement.

[0084] The compositions of the clinker are: 22.10% SiO2, 5.27% Al2O3, 3.42% Fe2O3, 66.07% CaO, 1.39% MgO, and 0.70% K2O.

[0085] The cement grinding aids prepared in the above examples and comparative examples were added to cement clinker at a ratio of 250 g / ton of cement clinker. The test results of cement grinding aids according to GB / T 26748-2011 are shown in the following table:

[0086] 28d flexural strength / MPa 28d compressive strength / MPa Example 1 6.1 33.3 Example 2 6.2 33.8 Example 3 6.3 34.7 Example 4 6.2 34.1 Comparative Example 1 4.8 26.2 Comparative Example 2 5.1 28.3 Comparative Example 3 5.4 29.5

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a high-efficiency cement grinding aid, comprising the following steps: 180-200 parts of alkali lignin are weighed by weight and mixed with water. Sodium hydroxide is added to adjust the pH value, and then the mixture is heated to 60-70°C and stirred to dissolve. 5-10 parts of dipropylene glycol are added, and the mixture is activated and reacted at 60-70°C for 50-70 minutes. The mixture is then heated to 70-80°C, 2-5 parts of an oxidant are added, and the mixture is reacted for 2-3 hours. Finally, 10-20 parts of a cerium-containing polyhydroxy oil-based polyacrylic acid polymer are added, and the mixture is reacted at 70-80°C for 1.5-2 hours. After the reaction is completed, the mixture is cooled to room temperature to obtain a high-efficiency cement grinding aid. The preparation method of the cerium-containing polyhydroxy oil-based polyacrylic acid polymer is as follows: Add 0.03-0.2 parts of dioctadecylamine, 15-25 parts of oleylamine, 130-200 parts of N,N-dimethylethanolamine, 5-12 parts of polyhydroxy acrylate, 0.0005-0.002 parts of cerium methacrylate, and 3-7 parts of diethanolamine to a sealed reaction kettle, introduce nitrogen, and stir to react at 70-80° C. for 1-3 hours. After the reaction is completed, add 2-4 parts of benzoyl peroxide, react at 70-78° C. for 60-180 minutes, and remove N,N-dimethylethanolamine by distillation under reduced pressure to obtain a cerium-containing polyhydroxy oleyl polyacrylic acid polymer; The polyhydroxy acrylate is at least one of U-1933R, U-1922, U-1908R, D-11, D-217, U-1907S, U-1906AD-5, U-845, U-2811S, U-2103, U-2108, U-2101N, U-2814-70, U-3100, and U-2815.

2. The method for preparing a high-efficiency cement grinding aid according to claim 1, wherein: The oxidant is potassium permanganate, ammonium persulfate or sodium hypochlorite.

3. The method for preparing a high-efficiency cement grinding aid according to claim 1, wherein: The sodium hydroxide adjusts the pH to 11-12.

4. The method for preparing a high-efficiency cement grinding aid according to claim 1, wherein: Cement preparation: According to weight, 150-200 parts of clinker and 5-10 parts of gypsum are weighed, crushed to a particle size of 1-2 cm, mixed evenly, added with 0.05-0.2 parts of a high-efficiency cement grinding aid, put into a grinder and grind for 10-20 minutes to obtain cement.

5. The method for preparing a high-efficiency cement grinding aid according to claim 4, wherein: The compositions of the clinker are: 18-24% SiO2, 4.5-7.5% Al2O3, 3.2-4.8% Fe2O3, 62-74% CaO, 0.3-1.6% MgO, and 0.1-1.2% K2O.