阅读说明：本技术 一种高效粉煤灰活化剂及其制备方法 (High-efficiency fly ash activator and preparation method thereof ) 是由 张延年 崔长青 顾晓薇 海洪 王亭 张于于 康楠 王铁源 闫明程 于洋 李志军 于 2020-05-08 设计创作，主要内容包括：一种高效粉煤灰活化剂及其制备方法,属于建筑材料技术领域。所述高效粉煤活化剂的制备方法,包括以下步骤：(1)将高效减水剂、氟硅酸钠、三乙醇胺和纤维素醚按照各自的质量分数比例加入到,并在预设条件下进行反应,同时开始进行搅拌,制得混合物；(2)将脱硫石膏和氧化钙分别进行粉磨,使得研磨粒径达到标准；(3)将粉磨好的脱硫石膏,氧化钙和粉状速溶硅酸按照各自的质量分数加入到水中,再加入由步骤(1)制得的混合物进行混合搅拌,持续30分钟后,制得活化剂。本发明能够消耗大量固废,使得化学石膏与粉煤灰反应能够减少混凝土后期的收缩,且粉状速溶硅酸钠能够解决粉煤灰混凝土早期强度过低的问题。(An efficient fly ash activator and a preparation method thereof, belonging to the technical field of building materials. The preparation method of the high-efficiency powdered coal activator comprises the following steps: (1) adding a high-efficiency water reducing agent, sodium fluosilicate, triethanolamine and cellulose ether according to respective mass fraction proportion, reacting under a preset condition, and simultaneously starting stirring to prepare a mixture; (2) respectively grinding the desulfurized gypsum and the calcium oxide to enable the grinding particle size to reach the standard; (3) adding the ground desulfurized gypsum, calcium oxide and powdery instant silicic acid into water according to respective mass fractions, adding the mixture prepared in the step (1), mixing and stirring for 30 minutes to prepare the activating agent. The invention can consume a large amount of solid waste, so that the reaction of the chemical gypsum and the fly ash can reduce the later-stage shrinkage of concrete, and the powdery instant sodium silicate can solve the problem of low early strength of the fly ash concrete.)

1. A high-efficiency powdered coal activator is characterized in that: the high-efficiency powdered coal activator is a mixture consisting of desulfurized gypsum, calcium oxide, powdery instant sodium silicate, a high-efficiency water reducing agent, sodium fluosilicate, triethanolamine, cellulose ether and water.

2. The high-efficiency pulverized coal activator according to claim 1, wherein the mass fraction ratio of the desulfurized gypsum, the calcium oxide, the powdery instant sodium silicate, the high-efficiency water reducing agent, the sodium fluosilicate, the triethanolamine, the cellulose ether and the water is as follows: 25% -40%: 15% -25%: 10% -20%: 7% -15%: 5% -10%: 0.02% -0.05%: 0.1% -0.3%: 15 to 30 percent.

3. The high-efficiency pulverized coal activator according to claim 2, wherein the high-efficiency water reducing agent is selected from the group consisting of naphthalene-based high-efficiency water reducing agents, sulfamate-based high-efficiency water reducing agents, and polycarboxylate-based high-efficiency water reducing agents.

4. The high efficiency pulverized coal activator according to claim 3, wherein the cellulose ether is composed of hydroxyethyl cellulose, carboxymethyl hydroxyethyl cellulose, ethyl cellulose, and carboxymethyl cellulose.

5. The high-efficiency pulverized coal activator according to claim 4, wherein the mass fraction ratio of the hydroxyethyl cellulose, the carboxymethyl hydroxyethyl cellulose, the ethyl cellulose and the carboxymethyl cellulose is as follows: 1-2: 0.5-1: 0.1-0.5: 1-2.

6. The method for preparing the high-efficiency powdered coal activator according to claim 6, which comprises the following steps:

(1) adding a high-efficiency water reducing agent, sodium fluosilicate, triethanolamine and cellulose ether according to respective mass fraction proportion, reacting under a preset condition, and simultaneously starting stirring to prepare a mixture;

(2) respectively grinding the desulfurized gypsum and the calcium oxide to enable the grinding particle size to reach the standard;

(3) adding the ground desulfurized gypsum, calcium oxide and powdery instant silicic acid into water according to respective mass fractions, adding the mixture prepared in the step (1), mixing and stirring for 30 minutes to prepare the activating agent.

7. The preparation method of the high-efficiency pulverized coal activator according to claim 6, wherein the preset conditions in the step (1) are that the preset pressure value is 4MPa, the preset temperature is 50 ℃, and the stirring time is two hours.

8. The preparation method of the high-efficiency pulverized coal activator according to claim 6, wherein the standard in the step (2) is specifically that the grinding grain size is less than 7 mm.

Technical Field

The invention belongs to the technical field of building materials, and particularly relates to a high-efficiency fly ash activating agent and a preparation method thereof.

Background

With the global rise of the construction industry, a great deal of research on construction materials has been generated. At the same time, industrial solid waste is also increasing in quantity. As the amount of industrial solid waste accumulated is increased and the amount of non-renewable resources for construction is decreased, the demand for application of industrial solid waste to construction materials is also increased.

The main sources of industrial solid wastes in daily production and life are as follows: coal gangue produced in coal industry; blast furnace slag, steel slag, red mud and the like produced in the metallurgical industry; fly ash and slag produced by fuel power plants and urban central heating systems; chemical gypsum, carbide slag, caustic sludge, and the like produced in the chemical industry and other industries; waste rock and tailings generated by mining metal ores, and the like.

The resources are increasingly in shortage and the energy is in shortage. The storage amount of non-renewable resources such as coal, petroleum, natural gas and the like in China is limited, and most of the non-renewable resources are exploited as main energy; the land desertification is becoming more and more serious, and the per capita land resources are less and less.

There is an ever increasing demand for building materials. The industrialization and urbanization process of China is accelerated continuously, large-scale infrastructure needs a large amount of building materials, particularly wall materials, and about hundred million standard bricks are needed every year.

Advantageous conditions of application of industrial solid wastes to building materials industrial solid materials are widely applied to the field of building materials, and have the following characteristics: the method has the advantages that the method has a large variety, large yield and wide distribution, is uniformly discharged all year round, and can be used as a stable available resource; and secondly, the phase composition is relatively stable, the chemical components are similar to those of the building material raw materials, and the building material has potential activity and is suitable for being used as the raw materials of the building material. In a word, through scientific identification, most industrial solid wastes have the potential of producing building materials, and the industrial solid wastes can save the cost, create higher economic benefit, change waste into valuables and realize the recycling of limited resources as raw materials of the building materials.

At present, in the prior art, the fly ash in the industrial solid waste is usually added into the concrete to replace the cement, but the defect is that the early strength growth speed of the concrete is too low. The mixing amount is particularly remarkable when the mixing amount is high, and the concentration of a pore solution and ions in a fly ash-CaO-water system is low, so that the early hydration of the fly ash is very slow.

Disclosure of Invention

In order to solve the technical problem that the early strength increasing speed of concrete is too low in partial cement clinker replacement, the invention provides a fly ash-CaO-alkali solution system which is used for obviously improving the early hydration degree of fly ash, and the fly ash concrete prepared by adding an activating agent into the cement is used for reducing the using amount of the cement, relieving the problem of non-renewable resources, enhancing the compression resistance of the concrete and obviously improving the mechanical property of the concrete.

The invention provides a high-efficiency powdered coal activator which is a mixture consisting of desulfurized gypsum, calcium oxide, powdery instant sodium silicate, a high-efficiency water reducing agent, sodium fluosilicate, triethanolamine, cellulose ether and water.

Further, the high-efficiency pulverized coal activator according to claim 1, wherein the mass fraction ratio of the desulfurized gypsum, the calcium oxide, the powdery instant sodium silicate, the high-efficiency water reducing agent, the sodium fluosilicate, the triethanolamine, the cellulose ether and the water is as follows: 25% -40%: 15% -25%: 10% -20%: 7% -15%: 5% -10%: 0.02% -0.05%: 0.1% -0.3%: 15 to 30 percent.

Further, the high-efficiency water reducing agent can be a naphthalene high-efficiency water reducing agent, a sulfamate high-efficiency water reducing agent and a polycarboxylate high-efficiency water reducing agent.

Further, the cellulose ether is composed of hydroxyethyl cellulose, carboxymethyl hydroxyethyl cellulose, ethyl cellulose and carboxymethyl cellulose.

Further, the mass fraction ratio of the hydroxyethyl cellulose, the carboxymethyl hydroxyethyl cellulose, the ethyl cellulose and the carboxymethyl cellulose is as follows: 1-2: 0.5-1: 0.1-0.5: 1-2.

A preparation method of a high-efficiency powdered coal activator comprises the following steps:

(1) adding a high-efficiency water reducing agent, sodium fluosilicate, triethanolamine and cellulose ether according to respective mass fraction proportion, reacting under a preset condition, and simultaneously starting stirring to prepare a mixture;

(2) respectively grinding the desulfurized gypsum and the calcium oxide to enable the grinding particle size to reach the standard;

(3) adding the ground desulfurized gypsum, calcium oxide and powdery instant silicic acid into water according to respective mass fractions, adding the mixture prepared in the step (1), mixing and stirring for 30 minutes to prepare the activating agent.

Further, in the step (1), the preset conditions are that the preset pressure value is 4MPa, the preset temperature is 50 ℃, and the stirring time is two hours.

Further, the standard in the step (2) is specifically that the grinding particle size is less than 7 mm.

Has the advantages that: the high-efficiency pulverized coal activator provided by the invention can be activated with fly ash in a large-dosage cementing material to replace 50-60% of cement, and simultaneously, the fly ash concrete prepared by doping 7.5% of activator into 50% of fly ash in the cement is used to replace the cement, the cement material of each concrete is reduced by at least 50%, so that the use of the cement can be greatly reduced, and the sulfate erosion resistance and the chloride ion erosion resistance of the concrete can be greatly improved. After a proper amount of the high-efficiency powdered coal activator provided by the invention is mixed into the powdered coal ash, the components in the chemical gypsum and the powdered coal ash can be combined to form hydrated calcium sulphoaluminate, thereby the concrete expands in the early stage, the later contraction can be reduced, the volume stability of the concrete is increased, the lower neutral ion concentration of the pore solution in the fly ash-CaO-alkali solution system is obviously increased, the early hydration degree of the fly ash is obviously improved, a large amount of solid waste can be consumed, the chemical gypsum and the fly ash can react to reduce the later shrinkage of concrete, the powdered instant sodium silicate can solve the problem of low early strength of the fly ash concrete, and the addition of the high-efficiency powdered coal activator provided by the invention can further improve the stability of the concrete under the conditions of good workability and pumpability.

Detailed Description

The invention provides a high-efficiency pulverized coal activator which is a mixture consisting of desulfurized gypsum, calcium oxide, powdery instant sodium silicate, a high-efficiency water reducing agent, sodium fluosilicate, triethanolamine, cellulose ether and water, wherein the sodium fluosilicate can solve the problem that the concrete solidification early strength is too slow after a large amount of fly ash is doped, and the problem that the concrete solidification early strength is low after the fly ash is doped into cement is solved. In addition, the powdery instant sodium silicate is strong alkali weak acid salt, after rapid hydrolysis, the solution can contain higher concentration of hydroxide ions and weak acid ions, so that partial Si-O, Al-O bonds in the original glassy network with higher polymerization degree are broken to form unsaturated active bonds to accelerate the reaction with calcium hydroxide, and hydrates with better gelling properties, such as calcium silicate hydrate, calcium aluminate hydrate, ettringite and the like, are generated, thereby being beneficial to the gelling and pressure resistance of concrete.

As a further improvement of the invention, the mass fraction ratio of the desulfurized gypsum, the calcium oxide, the powdery instant sodium silicate, the high-efficiency water reducing agent, the sodium fluosilicate, the triethanolamine, the cellulose ether and the water is as follows: 25% -40%: 15% -25%: 10% -20%: 7% -15%: 5% -10%: 0.02% -0.05%: 0.1% -0.3%: 15 to 30 percent.

As a further improvement of the invention, the high-efficiency water reducing agent can be specifically a naphthalene-based high-efficiency water reducing agent, a sulfamate-based high-efficiency water reducing agent and a polycarboxylate-based high-efficiency water reducing agent, the high-efficiency water reducing agent increases the fluidity of concrete, and after the fly ash is added to the concrete, the high-efficiency water reducing agent can reduce the using amount of water and enhance the strength of the concrete without increasing the using amount of cement.

As a further improvement of the invention, the cellulose ether is composed of hydroxyethyl cellulose, carboxymethyl hydroxyethyl cellulose, ethyl cellulose and carboxymethyl cellulose.

As a further improvement of the invention, the mass fraction ratio of the hydroxyethyl cellulose, the carboxymethyl hydroxyethyl cellulose, the ethyl cellulose and the carboxymethyl cellulose is as follows: 1-2: 0.5-1: 0.1-0.5: 1-2.

A preparation method of a high-efficiency powdered coal activator comprises the following steps:

(1) adding a high-efficiency water reducing agent, sodium fluosilicate, triethanolamine and cellulose ether according to respective mass fraction proportion, reacting under a preset condition, and simultaneously starting stirring to prepare a mixture;

(2) respectively grinding the desulfurized gypsum and the calcium oxide to enable the grinding particle size to reach the standard;

(3) adding the ground desulfurized gypsum, calcium oxide and powdery instant silicic acid into water according to respective mass fractions, adding the mixture prepared in the step (1), mixing and stirring for 30 minutes to prepare the activating agent.

As a further improvement of the invention, in the step (1), the preset conditions are that the preset pressure value is 4MPa, the preset temperature is 50 ℃, and the stirring time is two hours.

As a further improvement of the invention, the standard in the step (2) is specifically that the grain size of the ground powder is less than 7 mm.

The following are specific examples.