An iron aluminate cement clinker, a solid waste-based high-strength iron aluminate cement and a preparation method thereof

Abstract

The present invention discloses a ferroaluminate cement clinker, a solid waste-based high-strength ferroaluminate cement, and a preparation method. The ferroaluminate cement clinker is obtained by calcining and rapidly cooling modified phosphogypsum with solid waste materials such as limestone, tungsten tailings, and lepidolite smelting slag. The ferroaluminate cement clinker is then mixed with desulfurized gypsum, fly ash, and a cement admixture to obtain the solid waste-based high-strength ferroaluminate cement. The ferroaluminate cement, which uses various mining and smelting solid wastes as its primary raw materials, significantly reduces costs and exhibits high early strength, fast construction speed, and excellent resistance to chloride ion and sulfate corrosion. It can be widely used in rapid construction and repair projects for marine engineering or various concrete buildings, achieving efficient recycling of solid wastes. The cement has potential application value and significant economic and social benefits.

Description

Technical Field

[0001] The present invention relates to a ferroaluminate cement clinker and a preparation method thereof, and also relates to a solid waste-based high-strength ferroaluminate cement composed mainly of the ferroaluminate cement clinker and combined with desulfurized gypsum and fly ash, belonging to the technical field of comprehensive utilization of solid waste. Background Art

[0002] Currently, the concept of "carbon peak and carbon neutrality" is gradually permeating all aspects of current economic and social development. Efficiently and pragmatically implementing energy conservation, carbon reduction, and efficiency improvements is a key focus for building a circular economy and supporting carbon reduction initiatives. Exploring the comprehensive treatment of bulk solid waste materials, while ensuring safety and environmental protection, has become a current research hotspot. Within this context, bulk solid wastes such as smelting slag, industrial by-product gypsum, and mine dressing waste are being widely used in research areas such as soil improvement, underground backfill, and building materials.

[0003] Cement, especially specialty cement, is an indispensable raw material for concrete construction and marine resource development projects. For traditional Portland cement, sulfates and chlorides in seawater, among other substances, can erode its surface during long-term immersion. These salts can penetrate into structures through ion exchange, damaging the cement and concrete structures, reducing their durability and corrosion resistance.

[0004] The preparation of traditional marine cement mainly focuses on the processing and improvement of cement. Chinese invention patent CN 113698117A discloses a method for preparing a solid waste-based high-iron sulfoaluminate marine cementitious material, emphasizing the superiority of solid waste-based high-iron sulfoaluminate clinker, but the specific preparation method and effect of the clinker are not clearly described. Chinese invention patent CN116354680 A discloses a high-crack-resistant and high-corrosion-resistant marine concrete and its preparation method, which emphasizes the optimization and improvement of the added modified internal curing materials (internal curing agents, graphene nanosheets, adhesives, etc.) on composite cement (sulfoaluminate cement or ferroaluminate cement, etc.), which is only reflected in the optimization of the anti-corrosion ability of the composite cement itself. Chinese invention patent CN115448681 B discloses a ferroaluminate cement for repair and its preparation method, which mainly describes the rapid repair effect of ferroaluminate cement in marine engineering applications, and still focuses on the performance optimization of cement. Summary of the Invention

[0005] In response to the current technical problems of the difficulty in utilizing bulk solid waste and the high cost and high price of existing traditional marine engineering concrete, the present invention is based on solid waste materials and utilizes the self-mineralization effect between components contained in various solid wastes. While meeting the calcination conditions of ferroaluminate cement clinker, it also improves the performance of the clinker. A high-strength ferroaluminate cement based on solid waste materials has been developed to meet the needs of marine engineering repairs.

[0006] The first object of the present invention is to provide a ferroaluminate cement clinker, which can be combined with solid wastes such as desulfurized gypsum and fly ash to obtain ferroaluminate cement with high early strength, fast construction speed, and good resistance to chloride ion and sulfate corrosion.

[0007] The second object of the present invention is to provide a method for preparing ferroaluminate cement clinker, which uses a combination of solid wastes such as tungsten tailings, phosphogypsum, and lithium mica smelting slag as main raw materials. It can not only meet the internal control requirements of clinker burning, but also solve the problems of large-scale solid waste utilization and environmental pollution. At the same time, high-quality cement clinker that can be used in marine engineering or various concrete construction projects is obtained, which greatly saves resources and costs, and the preparation method is simple, meeting industrial production requirements.

[0008] The third object of the present invention is to provide a solid waste-based high-strength ferroaluminate cement, which uses a variety of mine dressing solid waste as the main raw material, greatly reducing the cost, and has the characteristics of high early strength, fast construction speed, and good resistance to chloride ion and sulfate corrosion. It can be widely used in marine engineering or various concrete buildings for rapid construction and repair projects, realizing the efficient recycling of solid waste, has potential application value, and significant economic and social benefits.

[0009] In order to achieve the above technical objectives, the present invention provides a method for preparing ferroaluminate cement clinker, which comprises the following steps:

[0010] 1) stirring and mixing phosphogypsum, calcium oxide and sodium methyl silicate, then adding sodium fatty alcohol ether carboxylate and coconut oil diethanolamide, continuing to stir and mix evenly, and aging to obtain modified phosphogypsum;

[0011] 2) The limestone is crushed and ground, and then mixed with modified phosphogypsum, tungsten tailings and lepidolite smelting slag. The resulting mixture is calcined and rapidly cooled to obtain ferroaluminate cement clinker.

[0012] The ferroaluminate cement clinker of the present invention uses selected tungsten tailings as a corrective material and phosphogypsum and lepidolite smelting slag as clinker raw materials. These materials are calcined with limestone, which not only meets the internal control requirements of cement clinker firing, but also can obtain cement clinker with strength, repair speed, durability, corrosion resistance, etc. that meet the application requirements of marine engineering or various concrete construction projects. At the same time, it consumes a large amount of solid waste, which can solve the problems of low solid waste utilization rate and environmental pollution. Among them, the selected tungsten tailings as the corrective material mainly contain calcium iron garnet (Ca3Fe2(SiO4)3), calcium aluminum garnet (Ca3Al2(SiO4)3), calcium iron pyroxene (CaFe[Si2O6]), fluorite (CaF2), pyrite (FeS2), etc. The total content of effective substances is greater than 85wt%. During the calcination process, a large amount of iron and aluminum phases can be generated. During the cement hydration process, iron glue can be formed, which can not only adsorb chloride ions, but also improve structural density. At the same time, it can accelerate the hydration reaction of cement and improve the early strength and corrosion resistance of cement. As clinker raw materials, phosphogypsum and lepidolite smelting slag contain not only conventional clinker components such as calcium, silicon and aluminum, but also a variety of beneficial mineral components. These mineral components play a significant mineralization effect in the calcination and melting process. At the same time, many elements can improve the burnability of the raw material during the calcination process. Through the "multi-element chemical doping" effect, the clinker mineral composition is optimized, the mineral crystal structure changes (lattice distortion), and the liquid phase composition is changed. For example, the fluorite contained in the selected tungsten tailings and lepidolite smelting slag can convert lithium into fluorite during the high-temperature calcination process. The F, S, P, and Zn trapped in the amorphous glass phase in mica smelting slag and phosphogypsum melt out, disrupting the three-dimensional spatial network structure of the glass phase and fracturing the Si-O and Al-O layers. This reduces the time required for glass melting, enhances elemental homogenization, and promotes mineralization. Furthermore, fine-grained tungsten tailings act as non-clinker seeds during clinker calcination. The high calcium ion content in these tailings, along with calcium ions from limestone, facilitates adsorption reactions with silicate, weakening the critical nucleation barrier during crystal growth and reducing the energy required for the reaction. These mineralization effects, at a macro level, impact process power consumption, kiln decomposition rate, kiln output, decomposition furnace temperature, and f-CaO in the clinker production process. Furthermore, they enhance pre-decomposition, reduce kiln calcination power consumption, lower f-CaO content in the clinker, and lower calcination temperature. The complex ion reaction mechanism enriches the elemental composition of the clinker, increasing the potential for enriched hydration products during cement hydration and thus improving clinker quality. In addition, by using phosphogypsum as an auxiliary material, it can replace ordinary dihydrate gypsum and desulfurized gypsum, which can not only save resources and reduce production costs, but also solve the problem of large-scale solid waste utilization.The composition of phosphogypsum is relatively complex. In addition to calcium sulfate, it also contains incompletely decomposed phosphate rock, residual phosphoric acid, fluoride, acid-insoluble matter, organic matter, etc. Through modification, it can be solidified and impurities can be removed, and the acidic properties of the material can be changed. The modified phosphogypsum can also enhance the corrosion resistance of cement clinker, prevent the dissolution of heavy metals, and improve the impermeability and durability of cement.

[0013] As a preferred solution, the mass ratio of the phosphogypsum to the calcium oxide and the sodium methyl silicate is 500: (110-200): (45-65). Since phosphogypsum is acidic and contains harmful substances such as fluorine and heavy metals, it is difficult to be directly used in the preparation of ferroaluminate cement clinker. The present invention introduces an appropriate amount of calcium oxide for reaction, which not only neutralizes the acid therein to make it neutral or alkaline, but also converts harmful impurities, such as fluorine into calcium fluoride, and heavy metals are stabilized under alkaline conditions and converted into harmless substances. Sodium methyl silicate is mainly used as a waterproof and hydrophobic component. It achieves a waterproof effect by forming a water-repellent organic film (polysiloxane film) on the surface of the matrix. Sodium methyl silicate-modified phosphogypsum can produce a water-repellent polysiloxane film on the surface and pores of the system, effectively preventing the intrusion of external moisture, weakening the hygroscopic and acidifying properties of the system, and further preventing external moisture from entering to dissolve free ions, thereby improving the curing effect.

[0014] As a preferred embodiment, the mass ratio of the phosphogypsum to the sodium fatty alcohol ether carboxylate and the coconut oil diethanolamide is 500:(15-32):(40-55). The combined use of the two surfactants, sodium fatty alcohol ether carboxylate and coconut oil diethanolamide, can convert the phosphogypsum into hemihydrate gypsum during the phosphogypsum modification process, thereby increasing the purity of the gypsum in the phosphogypsum.

[0015] As a preferred solution, the mass ratio of the limestone to the tungsten tailings, the modified phosphogypsum, and the lepidolite smelting slag is 30-50:10-25:25-35:5-20. The ratio values are calculated based on the main components contained in the solid wastes of limestone, tungsten tailings, modified phosphogypsum, and lepidolite smelting slag, and the proportions of each main component. Controlling the proportions of each solid waste within a preferred range not only meets the internal control requirements for clinker firing, but also produces a more active ferroaluminate cement clinker.

[0016] As a more preferred solution, the limestone is crushed and ground to control the particle size to meet the sieve residue of 80μm≤18wt%.The main components of the limestone are: CaO>45wt%, calcination>40wt%.

[0017] As a more preferred solution, the main components of the tungsten tailings are: SiO2+Al2O3>40wt%, CaO>25wt%, Fe2O3>20wt%.

[0018] As a more preferred solution, the main components of the lepidolite smelting slag are: SiO2+Al2O3>60wt%, CaO>10wt%, CaF2>7wt%, the lepidolite smelting slag particles have an 80μm sieve residue of ≤5wt%, and the moisture content is 10±1%.

[0019] As a more preferred solution, the main chemical components of the phosphogypsum are: CaSO4·2H2O, CaSO4>85wt%, and the leachate after adding distilled water is weakly acidic and has a water content of 8-10%.

[0020] As a preferred solution, the calcination and quenching treatment conditions are: first, at a temperature of 1250-1350°C, holding for 30-50 minutes, and then air cooling. Under the preferred calcination temperature and time, mineral reconstruction can be achieved to convert it into active components of cement clinker.

[0021] The present invention also provides a ferroaluminate cement clinker obtained by the preparation method.

[0022] The present invention also provides a solid waste-based high-strength ferroaluminate cement, which comprises the ferroaluminate cement clinker, desulfurized gypsum, fly ash and cement admixture.

[0023] As a preferred embodiment, the solid waste-based high-strength ferroaluminate cement comprises the following components by weight: 80-90 parts of ferroaluminate cement clinker, 5-15 parts of desulfurized gypsum, 5-15 parts of fly ash, and 0.01-0.015 parts of cement admixture. Preferably, the solid waste-based high-strength ferroaluminate cement comprises the following chemical composition (measured in mass percentage): SiO2 2-10%, Al2O3 45-55%, CaO 40-55%, Fe2O3 12-25%, SO3 4-10%, C4A3 45-60%, C2S 3-15%, C3A 8-15%, and C4AF 20-40%.

[0024] As a more preferred solution, the desulfurization gypsum is of industrial grade, and its main component is CaSO4>90wt%.

[0025] As a more preferred solution, the fly ash is secondary fly ash, the main components of which are: SiO2>50wt%, Al2O3>30wt%.

[0026] As a preferred embodiment, the cement admixture is prepared by the following method: sodium aluminate, zero-hydrate sodium silicate, sodium hydroxide and water are mixed to obtain a pre-reaction liquid, sodium formate, monoethanol diisopropanolamine and polymerized aluminum are added to the pre-reaction liquid and stirred to obtain the cement admixture.

[0027] As a preferred solution, the mixing reaction is carried out at a temperature of 50 to 60° C. for 30 to 45 minutes.

[0028] As a preferred solution, the stirring reaction conditions are: at a temperature of 40 to 50° C. and for 2 to 35 minutes.

[0029] As a preferred solution, the mass ratio of the sodium aluminate to the sodium silicate anhydrous, the sodium hydroxide, and the water is (5-12):(3-15):(1.5-7.5):(45-70).

[0030] As a preferred solution, the mass ratio of the sodium formate to the monoethanol diisopropanolamine and the polymerized aluminum is (0.8-1.6): (8-24): (10-20).

[0031] As a preferred solution, the ratio of the mass of the pre-reaction liquid to the total mass of the sodium formate, the monoethanol diisopropanolamine and the polymerized aluminum is (0.25-1):1.

[0032] The cement admixture provided by the present invention is a high-quality activator, wherein sodium formate and monoethanol diisopropanolamine can play a strength-enhancing effect in the cement system, which is manifested in the early strength effect of sodium formate and the later strength guarantee effect of monoethanol diisopropanolamine. The alkaline system (sodium aluminate, sodium silicate, sodium hydroxide) of the admixture reacts with cement clinker to change the particle surface structure of the admixture by first depolymerizing and then condensing, forming units composed of [SiO4] and [AlO4] tetrahedral structures. The units are linked and bonded through shared oxygen atoms and participate in the hydration reaction together with C4A3, C2S, C3A, C4A, etc. in the cement, thereby forming a complex polyferroaluminate hydration product system with a three-dimensional spatial network structure. The formed cementitious system has a unique structure and rich and diverse hydration products, so that it has better working performance than ordinary silicate and aluminate cements, including higher mechanical properties, chemical corrosion resistance, heat resistance, rapid setting and heavy metal ion solidification.

[0033] Compared with the existing technology, the technical solution of the present invention brings the following beneficial technical effects:

[0034] The ferroaluminate cement clinker of the present invention uses selected tungsten tailings as a corrective material and solid wastes such as phosphogypsum and lepidolite smelting slag as main clinker raw materials. It can not only meet the internal control requirements of clinker firing, but also solve the problems of large-scale solid waste utilization and environmental pollution, and at the same time meet the use requirements of special cements such as marine engineering or various concrete construction projects.

[0035] The preparation method of the ferroaluminate cement clinker of the present invention can largely consume solid waste resources, save costs, and has a simple preparation process, thus meeting industrial production requirements.

[0036] The ferroaluminate cement clinker of the present invention is combined with desulfurized gypsum, fly ash and cement admixtures to obtain high-strength ferroaluminate cement, which has the characteristics of high early strength, fast construction speed, good resistance to chloride ion and sulfate corrosion, and can be applied to the rapid construction and repair projects of marine engineering or various concrete buildings, realizing the recycling of solid waste resources, has high application value, and generates significant economic and social benefits. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the claims of the present invention is not limited thereto.

[0038] The raw materials involved in the following specific embodiments are all conventional commercially available raw materials in the prior art, or conventional solid waste.

[0039] In the following specific examples and comparative examples, the cement admixture is prepared by the following method: sodium aluminate, zero-hydrate sodium silicate, sodium hydroxide, and deionized water are mixed in a mass ratio of 10:5:2.5:50 and added to a conical flask container, and the mixture is kept warm at 50°C for 30 minutes to obtain a pre-reaction liquid, and then a solid mixture of sodium formate, monoethanol diisopropanolamine, and polymerized aluminum is added, stirred and dissolved for 25 minutes to obtain a cement admixture; wherein the mass ratio of the pre-reaction liquid and the solid mixture is 1:1; the mass ratio of sodium formate, monoethanol diisopropanolamine, and polymerized aluminum is 1.5:10:10.

[0040] In the following specific examples and comparative examples, modified phosphogypsum is prepared by the following method: in a planetary mixer, phosphogypsum, calcium oxide and sodium methyl silicate are added in sequence at a mass ratio of 500:150:50, and stirred and mixed evenly for 25 minutes. Then, sodium fatty alcohol ether carboxylate and coconut oil diethanolamide are added at a mass ratio of 500:25:50 compared with phosphogypsum, and stirring and mixing is continued for 45 minutes. After mixed contact, the mixture is placed in a sealing tape and aged for 12 hours to obtain modified phosphogypsum.

[0041] In the following specific examples, calcium oxide, sodium methyl silicate, sodium metaaluminate, and sodium hydroxide were all analytical grade. Sodium fatty alcohol ether carboxylate, coconut diethanolamide, sodium formate, monoethanol diisopropanolamine, and polymerized aluminum were all industrial grade and commercially available.

[0042] Example 1

[0043] The raw materials of solid waste-based high-strength ferroaluminate cement are shown in Table 4.

[0044] The raw materials of ferroaluminate cement clinker are shown in Tables 1 and 2.

[0045] The preparation method of solid waste material-based high-strength ferroaluminate cement comprises the following steps:

[0046] (1) Preparation of ferroaluminate cement clinker: limestone is crushed and ground to a sieve residue of 80 μm ≤ 18%, and mixed with modified phosphogypsum, tungsten tailings, and lepidolite slag. The mixture is then calcined at a temperature of 1225° C. for 35 minutes and rapidly cooled by air to obtain ferroaluminate cement clinker.

[0047] (2) The ferroaluminate cement clinker, desulfurized gypsum and fly ash prepared above were mixed in a preset mass ratio, placed in a 5 kg cement test mill, and a set mass of cement admixture was added to grind together, and the specific surface area of the obtained ferroaluminate cement was controlled to be 360 ± 10 m 2 / kg, which is high-strength ferroaluminate cement based on solid waste materials.

[0048] Example 2

[0049] The raw materials of solid waste-based high-strength ferroaluminate cement are shown in Table 4.

[0050] The raw materials of ferroaluminate cement clinker are shown in Tables 1 and 2.

[0051] The preparation method of solid waste material-based high-strength ferroaluminate cement is shown in Example 1.

[0052] Example 3

[0053] The raw materials of solid waste-based high-strength ferroaluminate cement are shown in Table 4.

[0054] The raw materials of ferroaluminate cement clinker are shown in Tables 1 and 2.

[0055] The preparation method of solid waste material-based high-strength ferroaluminate cement comprises the following steps:

[0056] (1) Preparation of ferroaluminate cement clinker: limestone is crushed and ground to a sieve residue of 80 μm ≤ 18%, and mixed with modified phosphogypsum, tungsten tailings, and lepidolite slag. The mixture is then calcined at a temperature of 1350° C. for 40 minutes and rapidly cooled by air to obtain ferroaluminate cement clinker.

[0057] (2) The ferroaluminate cement clinker, desulfurized gypsum and fly ash prepared above were mixed in a preset mass ratio, placed in a 5 kg cement test mill, and a set mass of cement admixture was added to grind together, and the specific surface area of the obtained ferroaluminate cement was controlled to be 360 ± 10 m 2 / kg, which is high-strength ferroaluminate cement based on solid waste materials.

[0058] Example 4

[0059] The raw materials of solid waste-based high-strength ferroaluminate cement are shown in Table 4.

[0060] The raw materials of ferroaluminate cement clinker are shown in Tables 1 and 2.

[0061] The preparation method of solid waste material-based high-strength ferroaluminate cement comprises the following steps:

[0062] (1) Preparation of ferroaluminate cement clinker: limestone is crushed and ground to a sieve residue of 80 μm ≤ 18%, and mixed with modified phosphogypsum, tungsten tailings, and lepidolite slag. The mixture is then calcined at a temperature of 1300° C. for 45 minutes and rapidly cooled by air to obtain ferroaluminate cement clinker.

[0063] (2) The ferroaluminate cement clinker, desulfurized gypsum and fly ash prepared above were mixed in a preset mass ratio, placed in a 5 kg cement test mill, and a set mass of cement admixture was added to grind together, and the specific surface area of the obtained ferroaluminate cement was controlled to be 360 ± 10 m 2 / kg, which is high-strength ferroaluminate cement based on solid waste materials.

[0064] Comparative Example 1

[0065] Compared with Example 1, the differences are: modified phosphogypsum is replaced by desulfurized gypsum, tungsten tailings are selected to replace iron tailings, and lepidolite smelting slag is replaced by high-alumina clay. The remaining raw materials and specific preparation methods are the same as in Example 1.

[0066] The main chemical components of the desulfurized gypsum are CaSO4·H2O, CaSO4 89.74%.

[0067] The iron tailings contain 45.91% SiO2, 5.40% Al2O3 and 37.69% Fe2O3.

[0068] The high-alumina clay contains 48.46% SiO2, 24.15% Al2O3, 4.78% CaO and 9.21% Fe2O3.

[0069] Comparative Example 2

[0070] Compared with Example 1, the difference is that the phosphogypsum used is not modified, and the original phosphogypsum is used to prepare the calcined clinker. The remaining raw materials and specific preparation methods are shown in Example 1.

[0071] Comparative Example 3

[0072] Compared with Example 3, the difference is that the phosphogypsum used is not modified, and the original phosphogypsum is used to prepare the fired clinker. The remaining raw materials and specific preparation methods are shown in Example 3.

[0073] Comparative Example 4

[0074] Compared with Example 4, the difference is that no admixture is used in the preparation process of ferroaluminate cement, and the remaining raw materials and specific preparation method are the same as those in Example 4.

[0075] Comparative Example 5

[0076] Ordinary 42.5 rapid hardening cement available on the market.

[0077] Table 1 Chemical composition of ferroaluminate cement clinker raw materials in Examples 1 to 4 (unit: parts)

[0078]

[0079] Table 2 Composition of raw materials of ferroaluminate cement clinker (unit: part)

[0080] name limestone Modified phosphogypsum Tungsten tailings Lepidolite smelting slag Calcination temperature Holding time Example 1 46.5 29.94 14.54 9.02 1250℃ 35min Example 2 37.5 28.55 20.45 13.5 1250℃ 30min Example 3 43.1 30.88 11.52 14.5 1350℃ 40min Example 4 40.66 27.75 13.77 17.82 1300℃ 45min

[0081] Table 3 Comparative Example Ferroaluminate Cement Clinker Raw Material Composition (Unit: part)

[0082] name limestone Desulfurization gypsum Iron tailings High alumina clay Calcination temperature Holding time Comparative Example 1 45 31 9.2 14.8 1250℃ 35min name limestone Unmodified phosphogypsum Tungsten tailings Lepidolite smelting slag Calcination temperature Holding time Comparative Example 2 46.5 29.94 14.54 9.02 1250℃ 35min Comparative Example 3 42.47 31.88 10.2 15.45 1350℃ 40min name limestone Modified phosphogypsum Tungsten tailings Lepidolite smelting slag Calcination temperature Holding time Comparative Example 4 40.66 27.75 13.77 17.82 1300℃ 45min

[0083] Table 4 Composition of ferroaluminate cement raw materials (unit: part)

[0084] name clinker Desulfurization gypsum fly ash admixtures Example 1 80 11 9 0.01 Example 2 85 6 9 0.01 Example 3 88 5 7 0.012 Example 4 82 5.5 12.5 0.012 Comparative Example 1 81 10.5 8.5 0.01 Comparative Example 2 81.5 10 8.5 0.01 Comparative Example 3 85 5 10 0.01 Comparative Example 4 82 5.5 12.5 0

[0085] Performance Testing

[0086] The ferroaluminate cements of Examples 1 to 4 and Comparative Examples 1 to 5 were tested for setting time, compressive strength, chloride ion corrosion, and sulfate corrosion resistance, respectively. The testing methods were conducted in accordance with the requirements of GB / T20100972-T-609 and GB / T 31289-2014. The test results are shown in Table 5 below.

[0087] Table 5 Performance test results

[0088]

[0089] Test results demonstrate that the solid waste-based high-strength ferroaluminate cement of the present invention exhibits rapid setting, high early compressive strength, and a strong late-stage strength development trend. Chloride ion and sulfate corrosion tests also demonstrate its strong corrosion resistance. The solid waste-based high-strength ferroaluminate cement of the present invention not only meets the requirements of rapid construction, high-strength repairs, and marine engineering for cement concrete construction, but also utilizes a wide range of solid waste from mining and smelting, optimizing the performance of the cement while also meeting the requirements of energy conservation, consumption reduction, and green mining development.

[0090] It should be noted that the above embodiments are only some of the preferred embodiments of the present invention, and not all of them. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

Claims

1. A method for preparing ferroaluminate cement clinker, characterized in that: The following steps are involved: 1) stirring and mixing phosphogypsum, calcium oxide, and sodium methyl silicate, then adding sodium fatty alcohol ether carboxylate and coconut oil diethanolamide, continuing to stir and mix evenly, and aging to obtain modified phosphogypsum; the mass ratio of the phosphogypsum to the calcium oxide and the sodium methyl silicate is 500:(110-200):(45-65); the mass ratio of the phosphogypsum to the sodium fatty alcohol ether carboxylate and the coconut oil diethanolamide is 500:(15-32):(40-55); 2) crushing and grinding limestone, mixing it with modified phosphogypsum, tungsten tailings, and lepidolite smelting slag, and calcining and quenching the resulting mixture to obtain ferroaluminate cement clinker; wherein the mass ratio of the limestone to the tungsten tailings, the modified phosphogypsum, and the lepidolite smelting slag is 30-50:10-25:25-35:5-20.

2. The method for preparing ferroaluminate cement clinker according to claim 1, wherein: The conditions of the calcination and rapid cooling treatment are: first, at a temperature of 1250-1350° C., keeping the temperature for 30-50 minutes, and then using air cooling treatment.

3. A ferroaluminate cement clinker, characterized in that: Obtained by the preparation method according to claim 1 or 2.

4. A solid waste-based high-strength ferroaluminate cement, characterized by: The invention comprises the ferroaluminate cement clinker as claimed in claim 3, desulfurized gypsum, fly ash and cement admixture.

5. The solid waste-based high-strength ferroaluminate cement according to claim 4, characterized in that: The invention comprises the following components by weight: 80-90 parts of ferroaluminate cement clinker, 5-15 parts of desulfurized gypsum, 5-15 parts of fly ash and 0.01-0.015 parts of cement admixture.

6. The solid waste-based high-strength ferroaluminate cement according to claim 4 or 5, characterized in that: The cement admixture is prepared by the following method: sodium aluminate, zero-hydrate sodium silicate, sodium hydroxide and water are mixed to obtain a pre-reaction liquid, and sodium formate, monoethanol diisopropanolamine and polymerized aluminum are added to the pre-reaction liquid for stirring and reaction to obtain the cement admixture.

7. The solid waste-based high-strength ferroaluminate cement according to claim 6, characterized in that: The mixing reaction conditions are: at a temperature of 50-60° C., for 30-45 minutes; The stirring reaction conditions are: at a temperature of 40-50° C. and a reaction time of 25-35 min.

8. The solid waste-based high-strength ferroaluminate cement according to claim 6, characterized in that: The mass ratio of the sodium aluminate to the sodium silicate anhydrous, the sodium hydroxide, and the water is (5-12): (3-15): (1.5-7.5): (45-70); The mass ratio of the sodium formate to the monoethanol diisopropanolamine and the polymerized aluminum is (0.8-1.6): (8-24): (10-20); The ratio of the mass of the pre-reaction liquid to the total mass of the sodium formate, the monoethanol diisopropanolamine and the polymerized aluminum is (0.25-1):1.

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