Differentiated blending mineralizer for gypsum slag cement and preparation method thereof

Abstract

The invention provides a differentially-blended mineralizing agent for gypsum slag cement and a preparation method of the differentially-blended mineralizing agent. The differentially-blended mineralizer is composed of a slag activation layer, a clinker promotion layer, a gypsum balance layer and an environment adaptation layer, and the functional layers are dynamically blended according to the specifications and / or dosage of slag, clinker and gypsum in cement components and the working environment temperature. The mineralizing agent prepared by the invention can realize layered precise regulation and cross-layer synergistic interaction under the conditions that the slag activity index is S75 grade, S95 grade or S105 grade, the clinker grade is 42.5 or 52.5, the gypsum dosage is 5-25% and the working environment temperature is 0-35 DEG C, effectively optimizes the generation of ettringite (AFt) and hydrated calcium silicate (C-S-H), improves the early and later strength, stabilizes the setting time, and reduces the production cost. The limitation of a traditional mineralizer with a fixed formula is broken through, and the raw material adaptability, environmental stability and performance reliability of the mineralizer to gypsum slag cement are remarkably improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cement additives, and particularly relates to a differentiated deployment mineralizer for a gypsum-slag hydraulic cement and a preparation method thereof. BACKGROUND

[0002] The gypsum-slag hydraulic cement is a key material in water conservancy construction, mainly composed of clinker, gypsum, slag and a small amount of admixture. Due to its wide raw material sources, relatively low cost and certain mechanical property advantages, it has been widely used in dam, channel and coastal defense engineering fields. However, its performance is significantly affected by the characteristics of raw materials and environmental conditions, and there are many limitations in the existing technology.

[0003] On the one hand, the difference in slag activity (28-day activity index S75 grade to S105 grade) has a great impact on the hydration performance. The low-activity S75 grade slag has a dense glass structure, and the Si-O bond is difficult to break, so the activity release is insufficient; the high-activity S105 grade slag is easy to produce expansion defects due to excessive excitation, and the existing mineralizer uses a fixed excitation formula, which cannot meet the needs of different activity slags, resulting in large fluctuations in strength.

[0004] On the other hand, in the gypsum-slag cement system with low clinker (0-5%), the hydration core driving force is insufficient, the existing mineralizer has no targeted design, and the high-clinker system formula is still used, resulting in a 3-day compressive strength of less than 15 MPa, which cannot meet the early strength requirements of construction.

[0005] In addition, the fluctuation of gypsum dosage (5-25%) and the change of operating environment temperature (0-35℃) further aggravate the instability of performance. As the main sulfur source, the fluctuation of gypsum dosage easily leads to sulfur deficiency or sulfur excess, directly resulting in low material strength or expansion cracking; the environmental temperature affects the hydration rate, leading to low-temperature retardation and high-temperature false condensation phenomena, and the existing mineralizer lacks precise control means, making it difficult to adapt to complex scenes in industrial production.

[0006] Therefore, it is of great significance to develop a mineralizer that can be dynamically deployed according to the activity of slag, the grade of clinker, the dosage of gypsum and the operating environment temperature. SUMMARY

[0007] The purpose of the present application is to provide a differentiated deployment mineralizer for a gypsum-slag cement, which is composed of a slag activation layer, a clinker promotion layer, a gypsum balancing layer and an environment adaptation layer, and each functional layer is dynamically deployed according to the specifications and / or dosage of slag, clinker and gypsum in the cement composition and the operating environment temperature.

[0008] Among them, the slag accounts for more than 75% in the cement composition, and the specifications are 28-day activity index S75 grade, S95 grade or S105 grade.

[0009] The cement component contains 0-5% of clinker, and the specification is 42.5 or 52.5;

[0010] The cement component contains 5-15% or 15-25% of gypsum;

[0011] The working environment temperature is 0-15℃, 15-25℃ or 25-35℃;

[0012] The raw material composition of each functional layer includes:

[0013] The slag activating layer is composed of one or more of slaked lime, sodium carbonate, sodium sulfate, and caustic soda;

[0014] The clinker promoting layer is composed of one or more of calcium aluminate, calcium chloride, triethanolamine, glycerol, and silica fume;

[0015] The gypsum balancing layer is composed of sodium sulfate and aluminum sulfate;

[0016] The environment adapting layer is composed of one or more of calcium formate, calcium nitrate, calcium chloride, sodium thiocyanate, sodium dodecyl methyl sulfonate, and citric acid.

[0017] In a preferred embodiment, the gypsum in the cement component includes one or more of desulfurization gypsum, fluorogypsum, phosphogypsum, and calcined gypsum, and the purity of calcium sulfate dihydrate in the gypsum is above 80%.

[0018] In a preferred embodiment, the differentiated mineralization agent accounts for 3.0-5.0% of the total mass of slag, clinker, and gypsum in the cement component.

[0019] In a preferred embodiment, the dynamic regulation rule of the slag activating layer is:

[0020] When the 28-day activity index of the slag is S75, the slag activating layer is composed of slaked lime, sodium carbonate, sodium sulfate, and caustic soda in a mass ratio of 1:(1.4-1.6):(1.7-1.9):(0.4-0.6), and the layer accounts for 28-35% of the total mass of the mineralization agent; preferably, the slag activating layer is composed of slaked lime, sodium carbonate, sodium sulfate, and caustic soda in a mass ratio of 1:1.5:1.8:0.5, and the layer accounts for 32% of the total mass of the mineralization agent.

[0021] When the 28-day activity index of the slag is S95, the slag activating layer is composed of slaked lime, sodium carbonate, and sodium sulfate in a mass ratio of 1:(1.1-1.3):(1.4-1.6), and the layer accounts for 25-32% of the total mass of the mineralization agent; preferably, the slag activating layer is composed of slaked lime, sodium carbonate, and sodium sulfate in a mass ratio of 1:1.2:1.5, and the layer accounts for 28% of the total mass of the mineralization agent.

[0022] When the slag's 28-day activity index is S105, the slag activation layer is composed of hydrated lime, sodium carbonate, and sodium sulfate in a mass ratio of 1:(0.9-1.1):(1.1-1.3), and this layer accounts for 22-30% of the total mass of the mineralizer; preferably, the slag activation layer is composed of hydrated lime, sodium carbonate, and sodium sulfate in a mass ratio of 1:1.0:1.2, and this layer accounts for 25% of the total mass of the mineralizer.

[0023] In this invention, a slag activation layer is designed to disrupt the glassy structure of the slag, releasing active SiO2 and Al2O3 to provide a material basis for the formation of CSH and ettringite; at the same time, the pH value of the cement liquid phase is adjusted to 12.5-13.5 to create a highly alkaline hydration environment.

[0024] Regarding the specific raw material design, existing mineralizers use fixed activation formulas, which cannot be adapted to the characteristics of different active slags. Therefore, this invention designs a gradient activation system: for S75 grade slag, a strong activation system is constructed by a quaternary combination of hydrated lime, sodium carbonate, sodium sulfate, and caustic soda. The high OH- concentration of caustic soda is used to erode the glass structure, solving the problem of low-activity activation; for medium-activity S95 grade slag, the amount of activator is reduced, and the activation efficiency and stability are balanced by a ternary combination of hydrated lime, sodium carbonate, and sodium sulfate; for S105 grade high-activity slag, the proportion of activator is further reduced to avoid strength reduction caused by over-activation, achieving precise adaptation to different active slags.

[0025] In a preferred embodiment, the dynamic distribution rule of the clinker promoting layer is as follows:

[0026] When the clinker content is greater than 0 and the grade is 42.5, the clinker promoting layer is composed of calcium aluminate, calcium chloride, triethanolamine (TEA), glycerol, and silica fume in a mass ratio of 2:(1.1-1.3):(0.4-0.6):(0.4-0.6):(0.2-0.4), and this layer accounts for 18-25% of the total mass of the mineralizer; preferably, the clinker promoting layer is composed of calcium aluminate, calcium chloride, triethanolamine, glycerol, and silica fume in a mass ratio of 2:1.2:0.5:0.5:0.3, and this layer accounts for 22% of the total mass of the mineralizer;

[0027] When the clinker content is greater than 0 and the grade is 52.5, the clinker promoting layer is composed of calcium aluminate, calcium chloride, triethanolamine, glycerol, and silica fume in a mass ratio of 2:(0.9-1.1):(0.2-0.4):(0.4-0.6):(0.1-0.3), and this layer accounts for 15-22% of the total mass of the mineralizer; preferably, the clinker promoting layer is composed of calcium aluminate, calcium chloride, triethanolamine, glycerol, and silica fume in a mass ratio of 2:1:0.3:0.5:0.2, and this layer accounts for 18% of the total mass of the mineralizer;

[0028] When the clinker content is 0%, the clinker promoting layer is composed of calcium aluminate, glycerol, and silica fume in a mass ratio of 3:(0.9-1.1):(0.1-0.3), and this layer accounts for 12-20% of the total mass of the mineralizer; preferably, the clinker promoting layer is composed of calcium aluminate, glycerol, and silica fume in a mass ratio of 3:1:0.2, and this layer accounts for 15% of the total mass of the mineralizer.

[0029] In this invention, a clinker promoting layer is designed to enhance the hydration reaction of a low clinker (0-5%) system and supplement the Al required for ettringite formation. 3+ The dense structure required for CSH gel solves the technical bottlenecks such as insufficient hydration driving force and low early strength in traditional low clinker scenarios.

[0030] Regarding the specific raw material design, since the clinker content in gypsum slag cement is only 0-5%, the hydration core reaction is relatively weak. Therefore, this invention addresses the problem of slow Al2O3 release rate from slag in low clinker scenarios by designing the following raw material: calcium aluminate can rapidly provide Al. 3+ Triethanolamine is used as a molecular catalyst to activate the clinker surface, accelerating C3A hydration and C3S dissolution; silica fume fills the gaps between hydration products with ultrafine particles, improving structural density; glycerol forms hydrogen bonds with water molecules through hydroxyl groups, delaying water evaporation and avoiding early shrinkage cracking caused by low clinker system due to insufficient hydration products and poor water retention.

[0031] Furthermore, for different grades of clinker, 42.5 grade clinker has lower activity, requiring increased triethanolamine dosage to enhance catalysis; 52.5 grade clinker has higher activity, which can be addressed by reducing triethanolamine dosage to avoid concentrated heat of hydration; and in zero-clinker scenarios, calcium aluminate is used to replace clinker to provide Al. 3+ The core is to ensure the reaction continues.

[0032] In a preferred embodiment, the dynamic mixing rule of the gypsum balancing layer is as follows:

[0033] When the gypsum content is 5-15%, the gypsum balancing layer is composed of sodium sulfate and aluminum sulfate in a mass ratio of 2:(0.9-1.1), and this layer accounts for 20-35% of the total mass of the mineralizer; preferably, the gypsum balancing layer is composed of sodium sulfate and aluminum sulfate in a mass ratio of 2:1, and this layer accounts for 30% of the total mass of the mineralizer.

[0034] When the gypsum content is 15-25%, the gypsum balancing layer is composed of sodium sulfate and aluminum sulfate in a mass ratio of 1:(1.1-1.3), and this layer accounts for 20-30% of the total mass of the mineralizing agent; preferably, the gypsum balancing layer is composed of sodium sulfate and aluminum sulfate in a mass ratio of 1:1.2, and this layer accounts for 25% of the total mass of the mineralizing agent.

[0035] In this invention, a gypsum balancing layer is designed to precisely control SO4 in the cement system. 2- The concentration ensures that the CaO:Al2O3:CaSO4 generated from ettringite meets the molar ratio balance of 3:1:3, thus solving problems such as insufficient sulfur and low strength or excessive sulfur expansion caused by fluctuations in gypsum dosage.

[0036] In terms of specific raw material design, this invention achieves SO4 production through a sodium sulfate and aluminum sulfate system. 2- Dynamic regulation: Sodium sulfate has excellent water solubility and can rapidly release SO4. 2- This compensates for the sulfur deficiency in low-gypsum environments. If calcium sulfate is used instead, it will cause SO4 contamination. 2- Insufficient concentration leads to a reduction in the amount of ettringite formed.

[0037] After aluminum sulfate is hydrolyzed, it passes through Al 3+ with SO 45 2- The complexation process slowly releases SO4 2- At the same time, supplement Al 3+ To balance the risk of excessive sulfur in high gypsum environments, if aluminum sulfate is lacking, SO4... 2- An excessive amount can occur instantly, causing ettringite to form rapidly within 1-2 hours, leading to false coagulation.

[0038] In specific regulation, a high proportion of sodium sulfate is used for rapid sulfur replenishment in low gypsum scenarios; and the amount of aluminum sulfate is increased to enhance slow-release sulfur control in high gypsum scenarios.

[0039] In a preferred embodiment, the dynamic allocation rule of the environment adaptation layer is as follows:

[0040] When the ambient temperature is 0-15℃, the environmental adaptation layer is composed of calcium formate and calcium chloride in a mass ratio of (1.5-2.5):1, and this layer accounts for 5-25% of the total mass of the mineralizing agent; preferably, the environmental adaptation layer is composed of calcium formate and calcium chloride in a mass ratio of 2:1, and this layer accounts for 22% of the total mass of the mineralizing agent.

[0041] When the ambient temperature is 15-25℃, the environmental adaptation layer is composed solely of calcium nitrate, and this layer accounts for 5-25% of the total mass of the mineralizer; preferably, the environmental adaptation layer accounts for 18% of the total mass of the mineralizer.

[0042] When the ambient temperature is 25-35℃, the environmental adaptation layer is composed of sodium thiocyanate, sodium dodecanemethyl sulfonate, and citric acid in a mass ratio of (2-4):1:(0.2-0.4), and this layer accounts for 8-40% of the total mass of the mineralizer; preferably, the environmental adaptation layer is composed of sodium thiocyanate, sodium dodecanemethyl sulfonate, and citric acid in a mass ratio of 3:1:0.3, and this layer accounts for 22% of the total mass of the mineralizer.

[0043] In this invention, an environmental adaptation layer is designed to adjust the hydration rate at different operating temperatures (0-35℃), stabilize the setting time and strength development, and solve the defects of gypsum slag cement in high environmental sensitivity and poor temperature adaptability.

[0044] According to common knowledge in the art, operating temperature significantly affects the hydration rate. Low-temperature environments (0-15℃) reduce ion diffusion rates and delay hydration; high-temperature environments (25-35℃) accelerate gypsum dissolution and mineral hydration, easily leading to false setting or strength reduction. Existing mineralizers are not designed for temperature zones, resulting in significant performance differences under different environments. Therefore, this invention designs a specific adaptation scheme for temperature gradients: in low-temperature environments of 0-15℃, calcium formate reacts with Ca through carboxyl groups. 2+ The formation of complexes lowers the hydration activation energy and accelerates CSH formation; calcium chloride lowers the liquid phase freezing point and increases the Ca2+ level. 2+ Concentration, the two work synergistically to counteract low-temperature inhibition; in a normal temperature environment of 15-25℃, calcium nitrate alone can meet the requirements, and its Ca... 2+ It releases stable amounts of sodium thiocyanate, maintaining a balanced hydration rate and eliminating the risk of chloride ion corrosion, thus simplifying formulation while ensuring material performance. In high-temperature environments of 25-35℃, sodium thiocyanate reduces the dissolution rate by adsorbing SCN- onto the gypsum surface, while citric acid and Ca... 2+ Complexation reduces the supersaturation of the liquid phase, while sodium dodecanemethylsulfonate disperses and prevents agglomeration. The three work synergistically to prolong the setting time and avoid false coagulation.

[0045] Another object of the present invention is to provide a method for preparing any one of the differentiated mineralizers for gypsum slag cement, comprising the following steps:

[0046] S1 Determine the raw material ratio of each layer: Test the specifications and / or dosage of slag, clinker and gypsum in the cement composition, and the working environment temperature, and determine the raw material composition and dosage ratio of the slag activation layer, clinker promotion layer, gypsum balancing layer and environmental adaptation layer according to the rules.

[0047] S2 layered mixing:

[0048] First, add the slag activation layer raw material to the twin-screw mixer and mix at a speed of 300-500 r / min for 6-10 minutes until the material is uniform;

[0049] Add the raw materials for the clinker accelerator to the mixer and mix for 4-6 minutes at a speed of 200-400 r / min;

[0050] Finally, add the gypsum balance layer material and the environmental adaptation layer material to the mixer and mix for 10-15 minutes at a speed of 100-300 r / min to obtain the differentiated mineralizer.

[0051] In a preferred embodiment, before the S2 layer mixing, the raw materials for each layer are further pretreated, specifically:

[0052] Pretreatment of raw materials for slag activation layer: quicklime, sodium carbonate, sodium sulfate, and caustic soda flakes are pulverized by air jet mill and passed through a 0.075mm sieve;

[0053] Clinker accelerator raw material pretreatment: calcium aluminate is crushed to a particle size of 0.045-0.06 mm, silica fume is passed through a 45 μm sieve, and calcium chloride is crushed to a particle size of ≤1 mm;

[0054] Pretreatment of raw materials for gypsum balancing layer: Sodium sulfate and aluminum sulfate are crushed to a particle size of 0.06-0.08 mm;

[0055] Environmental compatibility layer raw material pretreatment: calcium formate, calcium nitrate, and sodium thiocyanate are pulverized to a particle size of 0.03-0.05 mm, sodium dodecanemethyl sulfonate is pulverized to a particle size of 0.01-0.02 mm, and citric acid is ground to a particle size of ≤0.05 mm.

[0056] Another object of the present invention is to provide the application of any one of the mineralizers in gypsum slag cement.

[0057] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0058] 1. Existing mineralizers use fixed formulas, which cannot cope with complex working conditions such as differences in slag activity, fluctuations in clinker ratio, changes in gypsum dosage, and temperature differences, resulting in poor performance stability. This invention innovatively constructs a four-level functional layer synergistic system, with each layer dynamically adjusted for specific core parameters: the slag activation layer is designed with activation intensity according to S75, S95, and S105 activity gradients; the clinker promotion layer is adapted to different grades of clinker and zero-clinker scenarios; the gypsum balancing layer responds to 5-20% fluctuations in gypsum dosage; and the environmental adaptation layer matches temperature changes from 0-35℃, breaking through the limitations of traditional mineralizers.

[0059] 2. To address the insufficient hydration driving force in gypsum-slag cement systems with a clinker content of 0-5%, this invention employs a composite strategy involving aluminum source replenishment, catalytic enhancement, and density strengthening through a clinker promoting layer: calcium aluminate rapidly provides Al. 3+ Triethanolamine ensures the formation of ettringite, enhances clinker hydration efficiency, and silica fume optimizes structural density. Even in zero-clinker scenarios, the reaction can be maintained through a calcium aluminate substitution system, filling the performance control gap in low-clinker, high-slag cement.

[0060] 3. To address the issue of insufficient or excessive sulfur caused by fluctuations in gypsum dosage, this invention specifically designs a dynamic control system for sodium sulfate and aluminum sulfate. In low gypsum scenarios, sodium sulfate is used to quickly replenish sulfur, while in high gypsum scenarios, aluminum sulfate is used to control sulfur through complexation and slow release. This stabilizes the molar ratio of ettringite formation at approximately 3:1:3, thus avoiding the adverse effects of fluctuations in gypsum dosage.

[0061] 4. In addition, this invention addresses the impact of ambient temperature on the hydration rate by designing an environmentally adaptable layer based on temperature response. In low-temperature environments, the reaction is accelerated by composite early-strength components. In normal-temperature environments, balanced hydration is maintained by stable calcium-releasing components. In high-temperature environments, the reaction rate is controlled by a synergistic system of slowing and dispersing. Thus, high-performance materials can be prepared within the ambient temperature range of 0-35℃.

[0062] 5. In this invention, the functional layers also generate a synergistic mechanism. The highly alkaline environment of the slag activation layer can enhance the catalytic efficiency of the clinker promoting layer. The sulfur concentration of the gypsum balancing layer is precisely matched with the calcium and aluminum ions of other layers. The environmental adaptation layer dynamically regulates the hydration rhythm. This synergistic effect breaks through the limitations of traditional mineralizers with fixed formulations and passive adaptation, significantly improving the raw material compatibility, environmental stability, and performance reliability of gypsum slag cement. Detailed Implementation

[0063] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0064] Unless otherwise specified, the technical means used in this invention are conventional means well known to those skilled in the art. All raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared using existing methods. Unless otherwise specified, all reagents used in this invention are of analytical grade.

[0065] Performance testing methods used in embodiments of the present invention:

[0066] Compressive strength: According to GB / T17671-1999, with a water-cement ratio of 0.5, using 40mm×40mm×160mm test blocks, the strength was tested at 3d and 28d under standard curing (20±1℃, relative humidity ≥90%).

[0067] Setting time: According to GB / T1346-2011, the initial setting time (when the test needle sinks to 4±1 mm from the bottom plate) and the final setting time were determined using a Vicat apparatus.

[0068] pH value: After stirring cement paste (water-cement ratio 0.5) for 3 minutes, take the supernatant and measure it with a pH meter;

[0069] Volume stability: The expansion rate after 28 days shall be determined by the Le Chatelier clamp method according to GB / T750-1992. A value greater than 0.5% is considered unqualified.

[0070] The pretreatment method for each layer of raw materials in this embodiment of the invention is as follows:

[0071] Raw material processing for slag activation layer: quicklime, sodium carbonate, sodium sulfate, and caustic soda flakes are pulverized by air jet mill and passed through a 0.075mm sieve;

[0072] Raw material processing for clinker accelerator layer: calcium aluminate is crushed to a particle size of 0.045-0.06 mm, silica fume is passed through a 45 μm sieve, and calcium chloride is crushed to a particle size of ≤1 mm;

[0073] Gypsum balancing layer raw material processing: Sodium sulfate and aluminum sulfate are crushed to a particle size of 0.06-0.08mm;

[0074] Environmental adaptation layer raw material processing: calcium formate, calcium nitrate, and sodium thiocyanate are crushed to a particle size of 0.03-0.05 mm, sodium dodecanemethyl sulfonate is crushed to a particle size of 0.01-0.02 mm, and citric acid is ground to a particle size of ≤0.05 mm.

[0075] Example 1

[0076] A differentiated mineralizer for gypsum slag cement, the preparation method of which includes:

[0077] (1) Test the specifications and dosage of slag, clinker and gypsum in cement composition, and the working environment temperature: S75 grade slag 85% (CaO 30%, Al2O3 18%), 42.5 grade clinker 5% (CaO 65%, Al2O3 8%), desulfurized gypsum 10% (calcium sulfate dihydrate purity 85%); the working environment temperature is 8℃.

[0078] The mineralizer accounts for 5% of the total cement mass, and the specific formula and proportions for each layer are as follows:

[0079] Slag activation layer (35%): hydrated lime: sodium carbonate: sodium sulfate: caustic soda = 1:1.5:1.8:0.5;

[0080] Clinker accelerator layer (25%): Calcium aluminate: Calcium chloride: TEA: Glycerol: Silica fume = 2:1.2:0.5:0.5:0.3;

[0081] Gypsum balancing layer (35%): Sodium sulfate: Aluminum sulfate = 2:1;

[0082] Environmental adaptation layer (5%): calcium formate: calcium chloride = 2:1.

[0083] (2) Layered mixing:

[0084] First, add the raw material of the slag activation layer to the twin-screw mixer and mix at 300 r / min for 80 minutes until the material is uniform;

[0085] Add the raw materials for the clinker accelerator to the mixer and mix for 6 minutes at 200 r / min.

[0086] Finally, add the gypsum balance layer material and environmental adaptation layer material to the mixer and mix for 12 minutes at 200 r / min to obtain the final product.

[0087] (3) The obtained mineralizer was added to the cement components in proportion and mixed thoroughly. Then, specimens were prepared for performance testing. The results were: 3-day compressive strength 27.5 MPa, 28-day strength 50.3 MPa, initial setting time 220 min, final setting time 335 min, ettringite molar ratio 3:1:3.0, and 28-day expansion rate 0.22%. This embodiment solved the problem of hydration lag of low-activity slag at low temperature through strong activation and low temperature adaptation design.

[0088] Example 2

[0089] A differentiated mineralizer for gypsum slag cement, the preparation method of which includes:

[0090] (1) Test the specifications and dosage of slag, clinker and gypsum in cement composition, and the working environment temperature: S95 grade slag 80% (CaO 32%, Al2O3 20%), 52.5 grade clinker 5% (CaO 68%, Al2O3 10%), phosphogypsum 15% (calcium sulfate dihydrate purity 82%); the working environment temperature is 20℃.

[0091] The mineralizer accounts for 4% of the total cement mass, and the specific formula and proportions for each layer are as follows:

[0092] Slag activation layer (30%): hydrated lime: sodium carbonate: sodium sulfate = 1:1.2:1.5;

[0093] Clinker accelerator layer (20%): Calcium aluminate: Calcium chloride: TEA: Glycerol: Silica fume = 2:1:0.3:0.5:0.2;

[0094] Gypsum balancing layer (30%): Sodium sulfate: Aluminum sulfate = 2:1;

[0095] Environmental adaptation layer (20%): calcium nitrate.

[0096] (2) The layered mixing process is the same as in Example 1.

[0097] (3) The obtained mineralizer was added to the cement components in proportion and mixed thoroughly. Then, specimens were prepared for performance testing. The results were: 3-day strength 25.2 MPa, 28-day strength 48.5 MPa, initial setting time 210 min, final setting time 315 min, ettringite molar ratio 3:1:2.9, expansion rate 0.21%. The medium strength activation system designed in this embodiment is adapted to the hydration requirements of medium-active slag, and the sulfur balance design avoids strength fluctuations.

[0098] Example 3

[0099] A differentiated mineralizer for gypsum slag cement, the preparation method of which includes:

[0100] (1) Test the specifications and dosage of slag, clinker and gypsum in cement composition, and the working environment temperature: S105 grade slag 80% (CaO 35%, Al2O3 22%), clinker 0%, fluorogypsum 20% (calcium sulfate dihydrate purity 80%); the working environment temperature is 32℃.

[0101] The mineralizer accounts for 3% of the total cement mass, and the specific formula and proportions for each layer are as follows:

[0102] Slag activation layer (22%): hydrated lime: sodium carbonate: sodium sulfate = 1:1.0:1.2;

[0103] Clinker accelerator layer (20%): Calcium aluminate: Glycerol: Silica fume = 3:1:0.2;

[0104] Gypsum balancing layer (20%): Sodium sulfate: Aluminum sulfate = 1:1.2;

[0105] Environmental compatibility layer (38%): Sodium thiocyanate: Sodium dodecanemethylsulfonate: Citric acid = 3:1:0.3.

[0106] (2) The layered mixing process is the same as in Example 1.

[0107] (3) The obtained mineralizer was added to the cement components in proportion, and after thorough mixing, specimens were prepared for performance testing. The results were as follows: 3-day strength 24.0 MPa, 28-day strength 47.2 MPa, initial setting time 225 min, final setting time 315 min, ettringite molar ratio 3:1:3.1, and expansion rate 0.23%. In this embodiment, calcium aluminate was used to replace clinker Al. 3+ With its high-temperature slow-setting design, it achieves a balance between strength and stability in zero-clinker scenarios.

[0108] Example 4

[0109] A differentiated mineralizer for gypsum slag cement, the preparation method of which includes:

[0110] (1) Test the specifications and dosage of slag, clinker and gypsum in cement composition, and the working environment temperature: S75 grade slag 88%, clinker 0%, calcined gypsum 12% (CaSO4 purity 90%); the working environment temperature is 18℃.

[0111] The mineralizer accounts for 5% of the total cement mass, and the specific formula and proportions for each layer are as follows:

[0112] Slag activation layer (32%): hydrated lime: sodium carbonate: sodium sulfate: caustic soda = 1:1.6:1.9:0.6;

[0113] Clinker accelerator layer (20%): Calcium aluminate: Glycerol: Silica fume = 3:1:0.3;

[0114] Gypsum balancing layer (30%): Sodium sulfate: Aluminum sulfate = 2:1.1;

[0115] Environmental adaptation layer (18%): calcium nitrate.

[0116] (2) The layered mixing process is the same as in Example 1.

[0117] (3) The obtained mineralizer was added to the cement components in proportion and mixed thoroughly. Then, specimens were prepared for performance testing. The results were: 3d strength 26.0 MPa, 28d strength 49.0 MPa, initial setting 205 min, final setting 320 min, ettringite molar ratio 3:1:2.9, expansion rate 0.22%. In this embodiment, the strong activation system and aluminum supplementation design compensated for the insufficient activity under zero clinker, and the sulfur balance regulation ensured the stable development of strength.

[0118] Example 5

[0119] A differentiated mineralizer for gypsum slag cement, the preparation method of which includes:

[0120] (1) Test the specifications and dosage of slag, clinker and gypsum in cement composition, and the ambient temperature of operation: 77% of S95 grade slag, 5% of 42.5 grade clinker and 18% of desulfurized gypsum; the ambient temperature of operation is 30℃.

[0121] The mineralizer accounts for 4.5% of the total cement mass. The specific formula and proportions for each layer are as follows:

[0122] Slag activation layer (28%): hydrated lime: sodium carbonate: sodium sulfate = 1:1.3:1.6;

[0123] Clinker accelerator layer (22%): Calcium aluminate: Calcium chloride: TEA: Glycerol: Silica fume = 2:1.3:0.6:0.6:0.4;

[0124] Gypsum balancing layer (25%): Sodium sulfate: Aluminum sulfate = 1:1.2;

[0125] Environmental compatibility layer (25%): Sodium thiocyanate: Sodium dodecanemethylsulfonate: Citric acid = 4:1:0.4.

[0126] (2) The layered mixing process is the same as in Example 1.

[0127] (3) The obtained mineralizer was added to the cement components in proportion and mixed thoroughly. Then, test specimens were prepared for performance testing. The results were: 3d strength 24.8MPa, 28d strength 48.0MPa, initial setting 215min, final setting 325min, ettringite molar ratio 3:1:3.0, and expansion rate 0.23%. In this embodiment, the expansion risk in high gypsum scenarios was avoided by high-temperature slow setting and high sulfur compatibility design.

[0128] Comparative Example 1: Fixed Formulation Mineralizer

[0129] The mineralizer accounts for 5% of the total cement mass and uses a general formula: 10% hydrated lime, 15% sodium sulfate, 5% calcium aluminate, 5% calcium nitrate, and 65% quartz sand. The application scenarios of Examples 1-5 were tested using the same formula.

[0130] The results were as follows: when the mineralizer of Comparative Example 1 with the fixed formulation was replaced with the mineralizer of Example 1, the 3-day strength was only 16.3 MPa (27.5 MPa in Example 1), the initial setting time was 470 min (220 min in Example 1), and the molar ratio of ettringite was 3:1:2.0.

[0131] When the mineralizer of Comparative Example 1 with a fixed formulation was used to replace the mineralizer of Example 3, the initial setting time was only 88 minutes (false setting) and the expansion rate was 0.73% (unqualified) after 28 days because there was no high-temperature retarding component.

[0132] When the mineralizer of Comparative Example 1 with a fixed formulation was used to replace the mineralizer of Example 5, the 28-day strength was 35.5 MPa (48.0 MPa in Example 5). It can be seen that the fixed formulation of the mineralizer cannot be adapted to different slag activity, gypsum ratio and temperature conditions.

[0133] Comparative Example 2

[0134] The only difference from Example 2 is that the gypsum balancing layer in the mineralizer formulation is replaced with an equal amount of quartz sand, while the other raw materials, dosages and methods are completely the same as in Example 2.

[0135] The results were as follows: 3-day strength 17.0 MPa (25.2 MPa in Example 2), 28-day strength 36.8 MPa (48.5 MPa in Example 2), initial setting time 290 min (slow setting), and ettringite molar ratio 3:1:1.7. In this comparative example, due to the lack of a sulfur regulation system of sodium sulfate and aluminum sulfate, the insufficient supply of sulfate ions led to a low amount of ettringite formation and a significant decrease in strength.

[0136] Comparative Example 3

[0137] The only difference from Example 3 is that the environmental adaptation layer in the mineralizer formulation is replaced with an equal amount of quartz sand, while the other raw materials, dosages and methods are completely the same as in Example 3.

[0138] The results were: initial setting time of 92 minutes (false setting under high temperature conditions, 225 minutes in Example 3), and expansion rate of 0.70% after 28 days (unqualified). This comparative example lacked the high-temperature retarding components of sodium thiocyanate and citric acid, resulting in concentrated heat release during cement hydration, a loose structure, and excessive expansion. This demonstrates the importance of the environmental adaptability layer of this invention in high-temperature conditions.

[0139] Comparative Example 4

[0140] The only difference from Example 1 is that the gypsum balancing layer in the mineralizer formulation contains only sodium sulfate and no aluminum sulfate, accounting for 35% of the mineralizer. The remaining raw materials, dosages, and methods are completely consistent with Example 1.

[0141] The results were as follows: 3-day strength 21.3 MPa (27.5 MPa in Example 1), 28-day expansion rate 0.66% (unqualified). In this comparative example, the rapid release of sulfate led to excessive sulfur in the early stage and insufficient sulfur in the later stage. The molar ratio of ettringite was 3:1:4.3. It can be seen that the slow-release sulfur control function of aluminum sulfate in this invention is of great significance.

[0142] Comparative Example 5

[0143] The only difference from Example 2 is that the mineralizer accounts for 2% of the total mass of cement, while the remaining raw materials, dosages and methods are completely the same as in Example 2.

[0144] The results were: 3-day strength 19.0 MPa (25.2 MPa in Example 2), 28-day strength 40.2 MPa (48.5 MPa in Example 2), ettringite molar ratio 3:1:2.6. In this comparative example, due to insufficient mineralizer dosage, CaO activation and Al... 3+ Inadequate replenishment and sulfur regulation led to incomplete reaction and low intensity.

[0145] In summary, through the four-layer synergistic design of the slag activation layer, clinker promotion layer, gypsum balancing layer and environmental adaptation layer, embodiments 1-5 of the present invention achieve a balance of 3:1:3 molar ratio of ettringite in different application scenarios at a low dosage of 3-5%. The strength, setting time and expansion rate of the resulting materials are all superior to those of the comparative examples, which fully demonstrates the important significance of the dynamic formulation of the present invention and solves the technical bottleneck of poor compatibility and unstable performance of traditional mineralizers.

[0146] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A differentiated mineralizer for gypsum slag cement, characterized in that, The differentiated mineralizer consists of a slag activation layer, a clinker promotion layer, a gypsum balancing layer, and an environmental adaptation layer. Each functional layer is dynamically adjusted according to the specifications and / or dosage of slag, clinker, and gypsum in the cement composition and the ambient temperature of the working environment. Among them, the cement composition contains more than 75% slag, and the specifications are 28-day activity index S75, S95 or S105. The cement composition contains clinker at a ratio of 0-5%, with a grade of 42.5 or 52.

5. The cement composition contains 5-15% or 15-25% gypsum. The operating environment temperature is 0-15℃, 15-25℃, or 25-35℃. The raw material composition of each functional layer includes: The slag activation layer is composed of one or more of quicklime, sodium carbonate, sodium sulfate, and caustic soda. The clinker promoting layer is composed of one or more of calcium aluminate, calcium chloride, triethanolamine, glycerol, and silica fume. The gypsum balancing layer is composed of sodium sulfate and aluminum sulfate; The environmental adaptation layer is composed of one or more of the following: calcium formate, calcium nitrate, calcium chloride, sodium thiocyanate, sodium dodecanemethyl sulfonate, and citric acid.

2. The differentiated mineralizer for gypsum slag cement as described in claim 1, characterized in that, The cement composition includes gypsum comprising one or more of desulfurized gypsum, fluorogypsum, phosphogypsum, and calcined gypsum, and the calcium sulfate dihydrate in the gypsum has a purity of over 80%.

3. The differentiated mineralizer for gypsum slag cement as described in claim 1, characterized in that, The differentiated mineralizer accounts for 3.0-5.0% of the total mass of slag, clinker and gypsum in the cement composition.

4. The differentiated mineralizer for gypsum slag cement as described in claim 1, characterized in that, The dynamic allocation rules for the slag activation layer are as follows: When the slag activity index is S75 after 28 days, the slag activation layer is composed of quicklime, sodium carbonate, sodium sulfate and caustic soda in a mass ratio of 1:(1.4-1.6):(1.7-1.9):(0.4-0.6), and this layer accounts for 28-35% of the total mass of the mineralizer. When the slag activity index is S95 after 28 days, the slag activation layer is composed of quicklime, sodium carbonate, and sodium sulfate in a mass ratio of 1:(1.1-1.3):(1.4-1.6), and this layer accounts for 25-32% of the total mass of the mineralizer. When the slag activity index is S105 after 28 days, the slag activation layer is composed of quicklime, sodium carbonate, and sodium sulfate in a mass ratio of 1:(0.9-1.1):(1.1-1.3), and this layer accounts for 22-30% of the total mass of the mineralizer.

5. The differentiated mineralizer for gypsum slag cement as described in claim 1, characterized in that, The dynamic allocation rule for the clinker promoting layer is as follows: When the clinker content is greater than 0 and the grade is 42.5, the clinker promoting layer is composed of calcium aluminate, calcium chloride, triethanolamine, glycerol, and silica fume in a mass ratio of 2:(1.1-1.3):(0.4-0.6):(0.4-0.6):(0.2-0.4), and this layer accounts for 18-25% of the total mass of the mineralizer; When the clinker dosage ratio is >0 and the grade is 52.5, the clinker promoting layer is composed of calcium aluminate, calcium chloride, triethanolamine, glycerol, and silica fume in a mass ratio of 2:(0.9-1.1):(0.2-0.4):(0.4-0.6):(0.1-0.3), and this layer accounts for 15-22% of the total mass of the mineralizer; When the clinker content is 0%, the clinker promoting layer is composed of calcium aluminate, glycerol, and silica fume in a mass ratio of 3:(0.9-1.1):(0.1-0.3), and this layer accounts for 12-20% of the total mass of the mineralizer.

6. The differentiated mineralizer for gypsum slag cement as described in claim 1, characterized in that, The dynamic adjustment rules for the gypsum balancing layer are as follows: When the gypsum content is 5-15%, the gypsum balancing layer is composed of sodium sulfate and aluminum sulfate in a mass ratio of 2:(0.9-1.1), and this layer accounts for 20-35% of the total mass of the mineralizer. When the gypsum content is 15-25%, the gypsum balancing layer is composed of sodium sulfate and aluminum sulfate in a mass ratio of 1:(1.1-1.3), and this layer accounts for 20-30% of the total mass of the mineralizing agent.

7. The differentiated mineralizer for gypsum slag cement as described in claim 1, characterized in that, The dynamic allocation rules for the environment adaptation layer are as follows: When the ambient temperature is 0-15℃, the environmental adaptation layer is composed of calcium formate and calcium chloride in a mass ratio of (1.5-2.5):1, and this layer accounts for 5-25% of the total mass of the mineralizing agent. When the ambient temperature is 15-25℃, the environmental adaptation layer is composed of calcium nitrate alone, and this layer accounts for 5-25% of the total mass of the mineralizer; When the ambient temperature is 25-35℃, the environmental adaptation layer is composed of sodium thiocyanate, sodium dodecanemethyl sulfonate, and citric acid in a mass ratio of (2-4):1:(0.2-0.4), and this layer accounts for 8-40% of the total mass of the mineralizer.

8. The method for preparing the differentiated mineralizer for gypsum slag cement as described in any one of claims 1-7, characterized in that, Includes the following steps: S1 Determine the raw material ratio of each layer: Detect the specifications and / or dosage of slag, clinker and gypsum in the cement composition, and the operating environment temperature, and determine the raw material composition and dosage ratio of the slag activation layer, clinker promotion layer, gypsum balancing layer and environmental adaptation layer according to the rules of claims 1-7. S2 layered mixing: First, add the slag activation layer raw material to the twin-screw mixer and mix at a speed of 300-500 r / min for 6-10 minutes until the material is uniform; Add the raw materials for the clinker accelerator to the mixer and mix for 4-6 minutes at a speed of 200-400 r / min; Finally, add the gypsum balance layer material and the environmental adaptation layer material to the mixer and mix for 10-15 minutes at a speed of 100-300 r / min to obtain the differentiated mineralizer.

9. The preparation method of the differentiated mineralizer for gypsum slag cement as described in claim 8, characterized in that, Before the S2 layered mixing, the raw materials for each layer are pretreated. The specific method is as follows: Pretreatment of raw materials for slag activation layer: quicklime, sodium carbonate, sodium sulfate, and caustic soda flakes are pulverized by air jet mill and passed through a 0.075mm sieve; Clinker accelerator raw material pretreatment: calcium aluminate is crushed to a particle size of 0.045-0.06 mm, silica fume is passed through a 45 μm sieve, and calcium chloride is crushed to a particle size of ≤1 mm; Pretreatment of raw materials for gypsum balancing layer: Sodium sulfate and aluminum sulfate are crushed to a particle size of 0.06-0.08 mm; Environmental compatibility layer raw material pretreatment: calcium formate, calcium nitrate, and sodium thiocyanate are pulverized to a particle size of 0.03-0.05 mm, sodium dodecanemethyl sulfonate is pulverized to a particle size of 0.01-0.02 mm, and citric acid is ground to a particle size of ≤0.05 mm.

10. The application of the mineralizer as described in any one of claims 1-7 in gypsum slag cement.