A fast-setting silico-aluminate phosphate composite cement without high-temperature curing and a preparation method thereof

Abstract

The application relates to a fast-setting silico-aluminate phosphate composite cement without high-temperature maintenance and a preparation method thereof, and relates to the field of civil engineering materials. The cement comprises main components and function-regulating components. The main components are measured as follows in percentage by mass: (1) silico-aluminate raw material 50-70%, (2) phosphate excitation raw material 20-30%, (3) calcium raw material 10-20%, and the sum of the three is 100%. In addition, the function-regulating components are additionally added according to the mass of the silico-aluminate raw material and the calcium raw material in the main components, and the dosages of the function-regulating components are as follows: (1) dissolving agent 4-8%, (2) polymerization accelerator 2-8%, and (3) early strength agent 4-12%. The preparation process comprises: ① raw material grinding and ② mixing. The silico-aluminate phosphate composite cement can be accelerated in the co-regulation of the function-regulating components, the co-regulation can accelerate the coagulation and hardening speed of the silico-aluminate phosphate composite cement, the high-temperature maintenance process is avoided, and the co-development of the coagulation and hardening and the mechanical properties of the silico-aluminate phosphate composite cement under room temperature conditions is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of civil engineering materials, and particularly relates to a fast-setting silicon-aluminum phosphate composite cement without high-temperature curing and a preparation method thereof. BACKGROUND

[0002] The silicon-aluminum phosphate composite cement is prepared by using silicon-aluminum materials as raw materials, under the action of phosphate excitation raw materials, through high-temperature driving to accelerate the depolymerization-polymerization reaction of minerals in the silicon-aluminum raw materials, and to form a three-dimensional network structure matrix. The material has high mechanical properties, high-temperature resistance, acid corrosion resistance, heavy metal solidification and other excellent properties, and has a wide potential application prospect in the fields of fireproofing and heat insulation, building, heavy metal solidification, nuclear waste sealing and the like.

[0003] However, the currently reported silicon-aluminum phosphate composite cement has a very slow setting and hardening rate at room temperature, and often needs high-temperature excitation, resulting in problems of increased carbon emission, high preparation energy consumption and high cost. Therefore, effective regulation and control of the setting and hardening of the silicon-aluminum phosphate composite cement at room temperature, and reduction of the preparation energy consumption and cost, are of great significance for the popularization and application of the silicon-aluminum phosphate composite cement. SUMMARY

[0004] In view of the above problems, the present application provides a fast-setting silicon-aluminum phosphate composite cement without high-temperature curing and a preparation method thereof. The present application uses silicon-aluminum materials and calcium materials as raw materials, under the action of phosphate excitation raw materials, through the heat released by the acid-base neutralization reaction between the phosphate excitation raw materials and the calcium raw materials to accelerate the dissolution of minerals in the silicon-aluminum raw materials, and under the mutual synergistic action of the functional regulation components, to accelerate the construction of the three-dimensional network of the matrix and the development of the mechanical properties, so as to solve the problems of long setting time and slow strength development of the silicon-aluminum phosphate composite cement at room temperature. The specific content of the present application is as follows:

[0005] A fast-setting silicon-aluminum phosphate composite cement without high-temperature curing and a preparation method thereof, characterized in that the fast-setting silicon-aluminum phosphate composite cement without high-temperature curing comprises main components and functional regulation components. The main components are measured as follows in terms of mass percentage: (1) silicon-aluminum raw materials 50%-70%, (2) phosphate excitation raw materials 20%-30%, (3) calcium raw materials 10%-20%, and the sum of the three is 100%. In addition, the functional regulation components are additionally added according to the mass of the silicon-aluminum raw materials and the calcium raw materials in the main components being 100%, and the dosages of the functional regulation components are as follows: (1) dissolution promoter 4%-8%, (2) polymerization promoter 2%-8%, (3) early strength agent 4%-12%.

[0006] The siliceous and aluminous raw material in the main component is one or two of fly ash, metakaolin and lithium slag, and the further preferred chemical composition of the siliceous and aluminous raw material has a content of SiO2 and Al2O3 greater than 30%.

[0007] The phosphate excitation raw material in the main component is one or two of aminotrimethylene phosphonic acid, disodium hydroxyethylidene diphosphate and sodium ethylenediamine tetramethylene phosphonate.

[0008] The calcareous raw material in the main component is one or two of steel slag, slag and quicklime, and the further preferred chemical composition of the calcareous raw material has a content of CaO greater than 30%.

[0009] The dissolution-promoting agent in the functional control component is one or two of ethyl carbamate, nicotinamide and polyoxyethylene sorbitan monostearate.

[0010] The polymerization accelerator in the functional control component is one or two of aluminum tert-butyl benzoate, dibenzyl sorbitol and phenolic ether phosphate potassium salt NP-4PK.

[0011] The early strength agent in the functional control component is one or two of calcium pantothenate, calcium hypophosphite and calcium metaphosphate.

[0012] The fast-setting siliceous and aluminous phosphate composite cement without high-temperature curing has the following preparation steps:

[0013] ① Raw material grinding: the siliceous and aluminous raw material and the calcareous raw material in the main component are placed in a ball mill according to the mass percentage, and the surface area of the obtained powder is controlled at 350m 2 / kg-550m 2 / kg.

[0014] ② Mixing: the powder obtained in step ① is placed in a mixer, and the phosphate excitation raw material is first added and mixed and stirred for 30 minutes according to the mass percentage; then the functional control component is added in addition according to the mass of the siliceous and aluminous raw material and the calcareous raw material in the main component being 100%, the addition sequence being: the dissolution-promoting agent is first added and stirred for 15 minutes, then the polymerization accelerator is added and stirred for 15 minutes, and finally the early strength agent is added and stirred for 30 minutes, to obtain the fast-setting siliceous and aluminous phosphate composite cement without high-temperature curing.

[0015] The present application aims at the problem that the setting and hardening performance and mechanical performance of the silico-aluminate phosphate composite cement under room temperature condition develop slowly at present. Through the introduction of calcium raw material and the synergistic effect of functional regulation components, the setting and hardening and mechanical performance of the silico-aluminate phosphate composite cement under room temperature condition are realized. The silico-aluminate phosphate composite cement prepared by the present application does not need high temperature maintenance, and its final setting time can be regulated to about 1.0 h under room temperature condition, the 3-day compressive strength can reach 35 MPa, and the 28-day compressive strength can reach 60 MPa. Specifically, under the action of the phosphate excitation raw material, the CaO in the introduced calcium raw material can react with the phosphate excitation raw material to release a large amount of heat, so as to accelerate the dissolution rate of the minerals in the silico-aluminate raw material. On the other hand, under the action of the functional regulation component, the dissolution rate of the minerals in the silico-aluminate raw material can be further accelerated, the content of the [SiO4] and [AlO4] oligomer structure units in the system can be increased, more effective components can be released to participate in the reaction, the reaction rate and the generation amount of the reaction product can be increased. Meanwhile, the used polymerization accelerator has strong binding capacity, can promote the polymerization of the oligomer structure units in the system, and accelerate the matrix network construction. On this basis, based on the salt effect of the early strength agent, the early strength agent can react with the phosphate excitation raw material, and can also participate in the construction of the silico-aluminate phosphate composite cement matrix network, improve the precipitation rate of the reaction product, accelerate the hydration process of the slurry, and promote the setting and hardening of the matrix. Through the synergistic promotion effect between the above components, the setting and hardening performance and the mechanical performance of the silico-aluminate phosphate composite cement under room temperature condition are realized.

[0016] The present application provides a fast-setting silico-aluminate phosphate composite cement without high temperature maintenance and a preparation method thereof, avoids the high temperature excitation link in the preparation process of the existing silico-aluminate phosphate composite cement, realizes the low energy consumption and low cost preparation of the silico-aluminate phosphate composite cement. Meanwhile, the realization of the setting and hardening performance and the mechanical performance of the silico-aluminate phosphate composite cement under room temperature condition realizes the application scenarios of the silico-aluminate phosphate composite cement. DETAILED DESCRIPTION

[0017] To further embody the effect brought by the present application, the technical effect of the present application is further explained below in combination with specific examples. The siliceous and aluminous raw material, the phosphate excitation raw material and the calcareous raw material in the main components of the listed examples are respectively represented by fly ash, disodium ethylidene bisphosphonate and steel slag, wherein the sum of the content of SiO2 and Al2O3 in the fly ash used is 35.7% to 50.4%, and the content of CaO in the steel slag used is 40.3% to 55.6%. According to the mass of the siliceous and aluminous raw material and the calcareous raw material in the main components being 100%, the functional control components are represented by polyoxyethylene sorbitan monostearate, phenolic ether phosphate potassium salt NP-4PK and calcium pantothenate. The specific details and technical effects of each case are described as follows.

[0018] Example 1

[0019] According to the mass percentage, the raw materials in the main components are weighed, wherein the functional control components are additionally added according to the mass of the siliceous and aluminous raw material and the calcareous raw material in the main components being 100%, and the details are as follows:

[0020] Main components: fly ash 50%, disodium ethylidene bisphosphonate 30%, steel slag 20%, and the sum of the three is 100%. The sum of the content of SiO2 and Al2O3 in the fly ash used in this example is 50.4%, and the content of CaO in the steel slag used is 55.6%.

[0021] Functional control components (added additionally according to the mass percentage of the siliceous and aluminous raw material fly ash and the calcareous raw material steel slag in the main components): polyoxyethylene sorbitan monostearate 8%, phenolic ether phosphate potassium salt NP-4PK 8%, and calcium pantothenate 12%.

[0022] ① Raw material grinding: 5 kg of fly ash and steel slag are accurately weighed according to the mass percentage of the main components and placed in a ball mill for grinding, so that the surface area of the obtained powder is controlled at 350m 2 / kg to 400m 2 / kg.

[0023] ② Mixing: the powder obtained in step ① is placed in a mixer, and the phosphate excitation raw material disodium ethylidene bisphosphonate is first added and mixed and stirred for 30 min according to the mass percentage; then the functional control components are added additionally according to the mass of the siliceous and aluminous raw material fly ash and the calcareous raw material steel slag in the main components being 100%, and the addition sequence is: first, the dissolution accelerator polyoxyethylene sorbitan monostearate is added and stirred for 15 min, then the polymerization accelerator phenolic ether phosphate potassium salt NP-4PK is added and stirred for 15 min, and finally the early strength agent calcium pantothenate is added and stirred for 30 min, to obtain the fast-setting siliceous and aluminous phosphate composite cement which does not require high-temperature curing.

[0024] Example 2

[0025] The main components are as follows in terms of mass percentage: fly ash 60%, hydroxyethylidene diphosphonic acid disodium 26%, and steel slag 14%, with the total of the three being 100%. The content of SiO2 and Al2O3 in the fly ash used in this example is 45.8%, and the content of CaO in the steel slag used is 47.2%.

[0026] The main components are as follows in terms of mass percentage: fly ash 60%, hydroxyethylidene diphosphonic acid disodium 26%, and steel slag 14%, with the total of the three being 100%. The content of SiO2 and Al2O3 in the fly ash used in this example is 45.8%, and the content of CaO in the steel slag used is 47.2%.

[0027] The functional control components (added additionally in terms of mass percentage of the main components, i.e., the mass percentage of the siliceous and calcareous raw materials) are as follows: polyoxyethylene sorbitan monostearate 7%, phenolic ether phosphate potassium salt NP-4PK 6%, and calcium pantothenate 8%.

[0028] ① Raw material grinding: 5 kg of fly ash and steel slag are accurately weighed according to the mass percentage of the main components and placed in a ball mill for grinding, so that the surface area of the obtained powder is controlled at 400 m 2 / kg-450 m 2 / kg.

[0029] ② Mixing: the powder obtained in step ① is placed in a mixer, and phosphate activating raw material hydroxyethylidene diphosphonic acid disodium is first added and mixed and stirred for 30 min; then the functional control components are added additionally, with the mass of the siliceous and calcareous raw materials in the main components being 100%, and the addition sequence being as follows: polyoxyethylene sorbitan monostearate, a dissolving promoter, is first added and stirred for 15 min, then polymeric promoter phenolic ether phosphate potassium salt NP-4PK is added and stirred for 15 min, and finally early strength agent calcium pantothenate is added and stirred for 30 min, to obtain the fast-setting siliceous and calcareous phosphate composite cement that does not require high-temperature curing.

[0030] Example 3

[0031] The main components are as follows in terms of mass percentage: fly ash 60%, hydroxyethylidene diphosphonic acid disodium 26%, and steel slag 14%, with the total of the three being 100%. The content of SiO2 and Al2O3 in the fly ash used in this example is 45.8%, and the content of CaO in the steel slag used is 47.2%.

[0032] The main components are as follows in terms of mass percentage: fly ash 60%, hydroxyethylidene diphosphonic acid disodium 26%, and steel slag 14%, with the total of the three being 100%. The content of SiO2 and Al2O3 in the fly ash used in this example is 45.8%, and the content of CaO in the steel slag used is 47.2%.

[0033] The functional control components (added additionally in terms of mass percentage of the main components, i.e., the mass percentage of the siliceous and calcareous raw materials) are as follows: polyoxyethylene sorbitan monostearate 7%, phenolic ether phosphate potassium salt NP-4PK 6%, and calcium pantothenate 8%.

[0034] ① Raw material grinding: 5 kg of fly ash and steel slag are accurately weighed according to the mass percentage of the main components and placed in a ball mill for grinding, so that the surface area of the obtained powder is controlled at 450 m 2 / kg-500 m 2 / kg.

[0035] ② Mixing: the powder obtained in step ① is placed in a mixer, and the phosphate-based excitation raw material hydroxyethylenediphosphonic acid disodium is first added and mixed for 30 min according to the mass percentage; then, the functional control components are added in addition to the mass of the siliceous and calcareous raw materials fly ash and steel slag in the main components, which is 100%, the addition sequence is: first, the dissolution promoter polyoxyethylene sorbitan monostearate is added and stirred for 15 min, then the polymerization promoter phenolic ether phosphate potassium salt NP-4PK is added and stirred for 15 min, and finally the early strength agent calcium pantothenate is added and stirred for 30 min, to obtain the fast-setting siliceous and alumina phosphate composite cement without high-temperature curing.

[0036] Example 4

[0037] The main components are weighed according to the mass percentage, and the functional control components are added in addition to the mass of the siliceous and calcareous raw materials in the main components, which is 100%, as follows:

[0038] Main components: fly ash 70%, hydroxyethylenediphosphonic acid disodium 20%, steel slag 10%, and the sum of the three is 100%. The content of SiO2 and Al2O3 in the fly ash used in this example is 35.7%, and the content of CaO in the steel slag used is 40.3%.

[0039] Functional control components (added in addition to the mass percentage of the siliceous and calcareous raw materials fly ash and steel slag in the main components): polyoxyethylene sorbitan monostearate 4%, phenolic ether phosphate potassium salt NP-4PK 2%, calcium pantothenate 4%.

[0040] ① Raw material grinding: 5 kg of fly ash and steel slag are accurately weighed according to the mass percentage of the main components and placed in a ball mill for grinding, so that the surface area of the obtained powder is controlled at 450 m 2 / kg-500 m 2 / kg.

[0041] ②Mixing: the powder obtained in step ① is placed in a mixer, and the phosphate excitation raw material hydroxyethylidene diphosphonic acid disodium is first added and mixed for 30 min according to the mass percentage; then, according to the mass of the silico-alumina raw material fly ash and the calcium raw material steel slag being 100%, the functional control component is additionally added, the addition sequence is: first, the dissolution promoter polyoxyethylene sorbitan monostearate is added and stirred for 15 min, then the polymerization promoter phenolic ether phosphate potassium salt NP-4PK is added and stirred for 15 min, and finally the early strength agent calcium pantothenate is added and stirred for 30 min, to obtain the fast-setting silico-alumina phosphate composite cement without high-temperature curing.

[0042] Comparative Example 1

[0043] In this comparative example, the dissolution promoter polyoxyethylene sorbitan monostearate is not added, and the rest is the same as Example 1.

[0044] Comparative Example 2

[0045] In this comparative example, the polymerization promoter phenolic ether phosphate potassium salt NP-4PK is not added, and the rest is the same as Example 2.

[0046] Comparative Example 3

[0047] In this comparative example, the early strength agent calcium pantothenate is not added, and the rest is the same as Example 3.

[0048] Comparative Example 4

[0049] In this comparative example, the functional control component is not added, and the rest is the same as Example 1.

[0050] Comparative Example 5

[0051] In this comparative example, the calcium raw material steel slag is completely replaced by the silico-alumina raw material fly ash, and the rest is the same as Example 1.

[0052] Comparative Example 6

[0053] In this comparative example, the calcium raw material steel slag is completely replaced by the silico-alumina raw material fly ash, and the functional control component is not added, and the rest is the same as Example 1.

[0054] The setting time of each example and comparative example is tested according to GB / T 1346-2019 "Cement Standard Consistency, Setting Time, and Stability Test Method"; the 3-day and 28-day compressive strength of each example and comparative example is tested according to GB / T 17671-2021 "Cement Mortar Strength Test Method (ISO Method)". The test results of each example and comparative example are shown in Table 1.

[0055] Table 1 Setting time and compressive strength of fast-setting silico-alumina phosphate composite cement without high-temperature curing

[0056]

[0057] As shown in Table 1, Comparative Example 6, lacking the addition of calcareous raw materials and functional regulating components, exhibited very slow setting and hardening of its prepared aluminosilicate phosphate composite cement, with a final setting time as long as 48.4 hours. Furthermore, its 3-day and 28-day compressive strengths were both low. In contrast, this invention, through the introduction of calcareous raw materials and the synergistic effect of functional regulating components, significantly shortened the setting time and substantially improved the strength of the aluminosilicate phosphate composite cements in Examples 1-4, achieving a synergistic development of the setting and hardening performance and mechanical properties of aluminosilicate phosphate composite cement under room temperature conditions.

[0058] Compared with Example 1, Comparative Example 1, due to the lack of a prosolvent in the functional regulating component, reduced the disintegration rate of minerals in the silicoaluminate raw material, resulting in a decrease in the content of oligomeric structural units such as [SiO4] and [AlO4], which are the effective components participating in the reaction in the system. This leads to a decrease in the reaction rate and the amount of reaction products generated, causing a slight extension of the matrix solidification time and a significant decrease in strength.

[0059] Compared with Example 2, Comparative Example 2, due to the lack of polymerization accelerator in the functional regulating component, reduced the degree of polymerization of oligomeric structural units in the matrix, resulting in a longer solidification time and a significant decrease in strength of the matrix.

[0060] Compared with Example 3, Comparative Example 3, due to the lack of early strength agent in the functional regulating component, reduced the precipitation rate of the reaction product and the hydration process of the slurry, which in turn led to a longer setting time of the matrix and a decrease in strength.

[0061] Compared with Example 1, Comparative Example 4, due to the absence of functional regulating components such as the solvent, polymerization accelerator and early strength agent, reduced the disintegration rate and reaction rate of the siliceous aluminate minerals and the precipitation rate and amount of products, resulting in a significant extension of the matrix solidification time and a substantial reduction in strength.

[0062] Compared with Example 1, Comparative Example 5 had a significant reduction in the heat released during the reaction due to the lack of calcium raw materials, which in turn significantly reduced the dissolution rate of minerals in the aluminosilicate raw materials. Even under the action of functional regulating components, the solidification, hardening and strength development of the matrix were still very slow.

[0063] In summary, it can be seen that the combined use of calcium-based raw materials and functional regulating components is an effective means to achieve the synergistic development of the setting and hardening performance and mechanical properties of silica-alumina phosphate composite cement at room temperature. The absence of any component will have an adverse effect on the performance of silica-alumina phosphate composite cement.

[0064] The above embodiments are only used for explaining the present application and do not constitute limitation to the scope of claims. Other alternative means that can be thought by those skilled in the art according to the content of the present application should be within the protection scope of the claims of the present application.

Claims

1. A rapid-setting silico-aluminate phosphate composite cement which does not require high-temperature curing, characterized in that, The fast-setting silico-aluminate phosphate composite cement without high-temperature curing comprises main components and function regulating components; wherein, the main components are measured as follows in percentage by mass: (1) silico-aluminate raw material 50%-70%, (2) phosphate excitation raw material 20%-30%, (3) calcareous raw material 10%-20%, and the sum of the three is 100%; in addition, the function regulating components are additionally added according to the mass of the silico-aluminate raw material and the calcareous raw material in the main components being 100%, and the dosages of the function regulating components are as follows: (1) dissolving agent 4%-8%, (2) polymerization accelerator 2%-8%, (3) early strength agent 4%-12%. The silico-aluminate raw material in the main components is one or two of fly ash, metakaolin and lithium slag, and the sum of the mass percentage contents of SiO2 and Al2O3 in the chemical composition of the silico-aluminate raw material is greater than 30%; the phosphate excitation raw material in the main components is one or two of aminotrimethylene phosphonic acid, hydroxyethylidene diphosphonic acid disodium and ethylenediamine tetramethylene phosphonic acid sodium; the calcareous raw material in the main components is one or two of steel slag, slag and quicklime, and the mass percentage content of CaO in the chemical composition of the calcareous raw material is greater than 30%. The dissolving agent in the function regulating components is one or two of ethyl carbamate, nicotinamide and polyoxyethylene sorbitan monostearate; the polymerization accelerator in the function regulating components is one or two of aluminum tert-butyl benzoate, dibenzyl sorbitol and phenolic ether phosphate potassium salt NP-4PK; and the early strength agent in the function regulating components is one or two of calcium pantothenate, calcium hypophosphite and calcium metaphosphate.

2. A process for the production of a fast-setting silico-aluminous phosphate composite cement without high temperature curing as claimed in claim 1, characterized in that The steps are as follows: 1) Raw material grinding: The siliceous raw material and the calcareous raw material in the main components are placed in a ball mill according to the mass percentage, and ground, so that the surface area of the obtained powder is controlled at 350 m 2 / kg-550 m 2 / kg; 2) Mixing: The ground raw material is mixed with the auxiliary components, and the mixture is mixed for 30 minutes to 2 hours by a ball mill or a pot mill, so that the mixture is uniformly mixed. 3) Pressing: The mixture obtained in the above step 2) is pressed into a green body having 2) mixing: the powder obtained in step 1) is placed in a mixer, and the phosphate excitation raw material is first added and mixed and stirred for 30 min; then, the function regulating components are additionally added according to the mass of the silico-aluminate raw material and the calcareous raw material in the main components being 100%, and the addition sequence is as follows: the dissolving agent is first added and stirred for 15 min, then the polymerization accelerator is added and stirred for 15 min, and finally the early strength agent is added and continuously stirred for 30 min, to obtain the fast-setting silico-aluminate phosphate composite cement without high-temperature curing.

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