Concrete mineral admixture prepared from waste incineration ash based on alkali activation-nano activation and preparation method of concrete mineral admixture

Abstract

The invention provides a concrete mineral admixture prepared from waste incineration ash based on alkali activation-nano activation and a preparation method of the concrete mineral admixture, and belongs to the technical field of concrete preparation. The concrete mineral admixture is prepared through the following steps that waste incineration ash is pretreated, and pretreated waste incineration ash is obtained; the pretreated waste incineration ash and a nanometer activating agent are subjected to first mixing, and activated waste incineration ash is obtained; mixing an alkali activator with water, and stirring to obtain an alkali activator solution; and performing secondary mixing on the alkali activator solution and the activated waste incineration ash, and stirring to obtain the concrete mineral admixture. The waste incineration ash in the obtained concrete mineral admixture is subjected to alkali excitation and nano activation treatment, the strength, durability and other performance of the concrete mineral admixture are remarkably improved, meanwhile, resource utilization of the waste incineration ash is achieved, and pollution is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of concrete preparation, and in particular to a concrete mineral admixture made from garbage incineration ash based on alkali excitation-nano activation and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization, waste incineration has become an important means of treating urban solid waste. However, the fly ash produced by waste incineration contains a large amount of heavy metals and is classified as hazardous solid waste. The traditional treatment method is mainly chemical stabilization and cement solidification followed by landfill, which not only occupies a large amount of land resources, but also may pose potential risks to the environment. In recent years, alkaline activation technology has been widely used in the preparation of civil engineering materials due to its excellent environmental friendliness and material properties. As an industrial by-product, the resource utilization of waste incineration ash has become an important way to solve the above problems.

[0003] As one of the most commonly used materials in modern construction, the performance of concrete directly affects the durability and safety of building structures. Mineral admixtures are an important component of concrete, which can improve the performance of concrete and enhance its durability and strength. At present, commonly used mineral admixtures include fly ash, slag powder, silica fume, etc. However, the resources of these mineral admixtures are limited, and the energy consumption and environmental pollution problems in their production process are prominent. At the same time, the use of the above-mentioned mineral admixtures to prepare concrete has limited improvement in the performance of concrete, and the compressive strength, durability and other properties of the obtained concrete have a large room for improvement.

[0004] Therefore, it is of great practical significance to provide a concrete mineral admixture with high strength and high durability obtained from waste incineration ash. Summary of the invention

[0005] The purpose of the present invention is to provide a concrete mineral admixture made from waste incineration ash based on alkali excitation-nano activation and a preparation method thereof, aiming to solve the technical problems in the prior art that concrete admixtures have poor improvement on the compressive strength, durability and other properties of concrete, and that waste incineration ash cannot be harmlessly treated.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a concrete mineral admixture made from waste incineration ash based on alkali excitation-nano activation, comprising the following components in parts by mass:

[0008] 40-50 parts of garbage incineration ash, 5-10 parts of nano activator, 5-10 parts of alkali activator, 20-30 parts of fly ash, and 3-5 parts of stabilizer.

[0009] Furthermore, the nano activator is one or more of nano silicon dioxide, nano calcium carbonate, nano calcium oxide or nano aluminum oxide; and the particle size of the nano activator is 1 to 100 nm.

[0010] Furthermore, the alkaline activator is one or more of sodium hydroxide, potassium hydroxide or sodium silicate.

[0011] Furthermore, the stabilizer is ethylene glycol.

[0012] The present invention also provides a method for preparing a concrete mineral admixture made from waste incineration ash based on alkali excitation-nano activation as described in the above technical solution, comprising the following steps:

[0013] Pre-treating the waste incineration ash to obtain pre-treated waste incineration ash;

[0014] The pretreated waste incineration ash is first mixed with a nano activator to obtain activated waste incineration ash;

[0015] mixing an alkali activator with water and stirring to obtain an alkali activator solution;

[0016] The alkali activator solution, activated waste incineration ash, stabilizer and fly ash are mixed for a second time and stirred to obtain the concrete mineral admixture.

[0017] Furthermore, the pretreatment includes washing, crushing, screening and grinding the waste incineration ash.

[0018] Furthermore, the first mixing is specifically to use ultrasonic dispersion to coat the nano activator on the surface of the pretreated waste incineration ash.

[0019] Furthermore, the frequency of the ultrasonic dispersion is 80 to 120 kHz, and the time is 30 to 40 minutes.

[0020] Furthermore, the mass ratio of the alkaline activator to water is 1 to 2:10.

[0021] The present invention also provides the use of the concrete mineral admixture described in the above technical solution or the concrete mineral admixture obtained by the preparation method described in the above technical solution in concrete.

[0022] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0023] The present invention adopts an alkali activator to perform alkali activation on the waste incineration ash, and activates the waste incineration ash through a nano activator, thereby significantly improving the activity of the waste incineration ash, improving the strength, durability and other properties of the waste incineration ash as a concrete mineral admixture, reducing dependence on traditional mineral admixtures, and reducing production costs; the present invention utilizes the waste incineration ash to prepare the concrete mineral admixture, realizes the resource utilization of the waste incineration ash, and reduces the pollution of the waste incineration ash to the environment. DETAILED DESCRIPTION

[0024] The present invention provides a concrete mineral admixture made from waste incineration ash based on alkali excitation-nano activation, comprising the following components in parts by mass:

[0025] 40-50 parts of garbage incineration ash, 5-10 parts of nano activator, 5-10 parts of alkali activator, 20-30 parts of fly ash, and 3-5 parts of stabilizer.

[0026] In the present invention, the concrete mineral admixture made from waste incineration ash based on alkali activation and nano-activation preferably includes the following components in parts by weight: 40-45 parts of waste incineration ash, 5-8 parts of nano-activator, 5-8 parts of alkali activator, 20-25 parts of fly ash, and 3-4 parts of stabilizer, and further preferably includes 40-42 parts of waste incineration ash, 5-6 parts of nano-activator, 5-7 parts of alkali activator, 20-23 parts of fly ash, and 3-4 parts of stabilizer.

[0027] The invention uses the garbage incineration ash as the main component of the concrete mineral admixture, thus realizing the resource utilization of the garbage incineration ash and reducing pollution.

[0028] In the present invention, the nano activator is preferably one or more of nano silicon dioxide, nano calcium carbonate, nano calcium oxide or nano aluminum oxide; the particle size of the nano activator is preferably 1 to 100 nm, more preferably 10 to 80 nm, and more preferably 30 to 70 nm.

[0029] When the present invention uses multiple nano-activators, the ratio between the different nano-activators is not particularly limited.

[0030] In the present invention, the alkaline activator is one or more of sodium hydroxide, potassium hydroxide or sodium silicate.

[0031] In the present invention, the stabilizer is preferably ethylene glycol.

[0032] The present invention adopts a stabilizer to stabilize the properties of the concrete mineral admixture after the components are mixed.

[0033] The present invention also provides a method for preparing a concrete mineral admixture made from waste incineration ash based on alkali excitation-nano activation as described in the above technical solution, comprising the following steps:

[0034] Pre-treating the waste incineration ash to obtain pre-treated waste incineration ash;

[0035] The pretreated waste incineration ash is first mixed with a nano activator to obtain activated waste incineration ash;

[0036] mixing an alkali activator with water and stirring to obtain an alkali activator solution;

[0037] The alkali activator solution, activated waste incineration ash, stabilizer and fly ash are mixed for a second time and stirred to obtain the concrete mineral admixture.

[0038] Pre-treating the waste incineration ash to obtain pre-treated waste incineration ash;

[0039] In the present invention, the pretreatment includes washing the waste incineration ash with water and then crushing it.

[0040] The present invention uses water washing to remove soluble salts that may exist in the water, and removes other impurities at the same time, and then crushes, screens and grinds the waste incineration ash until the particle size of the waste incineration ash is less than 0.075 mm, which is convenient for coating the surface of the nano activator and mixing with other components to achieve a better mixing effect.

[0041] The pretreated waste incineration ash is first mixed with a nano activator to obtain activated waste incineration ash;

[0042] In the present invention, the first mixing is specifically to use ultrasonic dispersion to coat the nano activator on the surface of the pretreated waste incineration ash.

[0043] The present invention adopts ultrasonic dispersion to coat the nano activator on the surface of waste incineration ash, improves the activation effect by limiting the frequency and time of ultrasonic dispersion, and helps to improve the comprehensive performance of waste incineration ash as concrete mineral admixture, such as strength and durability.

[0044] In the present invention, the frequency of the ultrasonic dispersion is preferably 80-120 khz, more preferably 80-100 khz, and more preferably 80-90 khz; the time is preferably 30-40 minutes, more preferably 30-38 minutes, and more preferably 30-35 minutes.

[0045] mixing an alkali activator with water and stirring to obtain an alkali activator solution;

[0046] The present invention adopts an alkali activator to activate the garbage incineration ash, thereby increasing the activity of the garbage incineration ash and further improving its comprehensive performance as a concrete mineral admixture.

[0047] In the present invention, the mass ratio of the alkaline activator to water is preferably 1 to 2:10, and more preferably 1 to 5:10.

[0048] The alkali activator solution, activated waste incineration ash, stabilizer and fly ash are mixed for a second time and stirred to obtain the concrete mineral admixture.

[0049] Finally, the alkaline activator solution, activated waste incineration ash, stabilizer and fly ash obtained above are mixed, and after mixing evenly, the concrete mineral admixture can be obtained.

[0050] The present invention also provides the use of the concrete mineral admixture described in the above technical solution or the concrete mineral admixture obtained by the preparation method described in the above technical solution in concrete.

[0051] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0052] Example 1

[0053] (1) 40 parts of waste incineration ash are placed in water for washing to remove soluble chloride salts and other impurities that may be present in the waste incineration ash, and then the washed waste incineration ash is crushed, screened and ground to a particle size of less than 0.075 mm, and then dried and stored for later use;

[0054] (2) mixing the dried waste incineration ash with 5 parts of nano calcium oxide with a particle size of 10 nm, and ultrasonically dispersing the mixture at a frequency of 80 kHz for 30 minutes to obtain activated waste incineration ash;

[0055] (3) mixing 5 parts of sodium hydroxide with 50 parts of water to obtain an alkaline activator solution;

[0056] (4) Mix the alkaline activator solution, activated waste incineration ash, 3 parts of ethylene glycol and 20 parts of fly ash, stir, and obtain a concrete mineral admixture after stirring evenly.

[0057] Example 2

[0058] (1) 50 parts of waste incineration ash are placed in water for washing to remove soluble chloride salts and other impurities that may be present in the waste incineration ash, and then the washed waste incineration ash is crushed, screened and ground to a particle size of less than 0.075 mm, and then dried and stored for later use;

[0059] (2) mixing the dried waste incineration ash with 10 parts of nano-silicon dioxide having a particle size of 30 nm, and dispersing the mixture by ultrasonication at a frequency of 120 kHz for 40 minutes to obtain activated waste incineration ash;

[0060] (3) mixing 10 parts of sodium hydroxide with 50 parts of water to obtain an alkaline activator solution;

[0061] (4) Mix the alkali activator solution, activated waste incineration ash, 5 parts of ethylene glycol and 30 parts of fly ash, stir, and obtain a concrete mineral admixture after stirring evenly.

[0062] Example 3

[0063] (1) 45 parts of waste incineration ash are placed in water for washing to remove soluble chloride salts and other impurities that may be present in the waste incineration ash, and then the washed waste incineration ash is crushed, sieved and ground to a particle size of less than 0.075 mm, and then dried and stored for later use;

[0064] (2) mixing the dried waste incineration ash with 8 parts of nano-alumina with a particle size of 70 nm, and dispersing them ultrasonically at a frequency of 100 kHz for 38 minutes to obtain activated waste incineration ash;

[0065] (3) mixing 7 parts of potassium hydroxide with 70 parts of water to obtain an alkaline activator solution;

[0066] (4) Mix the alkaline activator solution, activated waste incineration ash, 4 parts of ethylene glycol and 25 parts of fly ash, stir, and obtain a concrete mineral admixture after stirring evenly.

[0067] Example 4

[0068] (1) 42 parts of waste incineration ash are placed in water for washing to remove soluble chloride salts and other impurities that may be present in the waste incineration ash, and then the washed waste incineration ash is crushed, sieved and ground to a particle size of less than 0.075 mm, and then dried and stored for later use;

[0069] (2) mixing the dried waste incineration ash with 6 parts of nano calcium carbonate with a particle size of 100 nm, and dispersing them ultrasonically at a frequency of 90 kHz for 35 minutes to obtain activated waste incineration ash;

[0070] (3) mixing 5 parts of sodium silicate with 50 parts of water to obtain an alkaline activator solution;

[0071] (4) Alkaline activator solution, activated waste incineration ash, 5 parts of ethylene glycol and 23 parts of fly ash are mixed and stirred to obtain a concrete mineral admixture after stirring evenly.

[0072] Performance and testing

[0073] The concrete mineral admixture obtained in Example 1, water and cement were mixed in a mass ratio of 3:1:2 to obtain concrete test example 1; it was determined that concrete test example 1 had the following characteristics: 7d strength activity reached 80%, and 28d strength activity could reach 95%; the expansion rate reached 0.010%, which is equivalent to the expansion level of ordinary cement, and the strength is greatly improved compared to ordinary concrete.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A concrete mineral admixture made from waste incineration ash based on alkali activation and nano-activation, characterized in that: The composition includes the following components in parts by weight: 40-50 parts of garbage incineration ash, 5-10 parts of nano activator, 5-10 parts of alkali activator, 20-30 parts of fly ash, and 3-5 parts of stabilizer.

2. The concrete mineral admixture made from alkali-activated-nano-activated garbage incineration ash according to claim 1, characterized in that: The nano activator is one or more of nano silicon dioxide, nano calcium carbonate, nano calcium oxide or nano aluminum oxide; the particle size of the nano activator is 1-100 nm.

3. The concrete mineral admixture made from alkali-activated-nano-activated garbage incineration ash according to claim 1, characterized in that: The alkaline activator is one or more of sodium hydroxide, potassium hydroxide or sodium silicate.

4. The concrete mineral admixture made from alkali-activated-nano activated garbage incineration ash according to claim 1, characterized in that: The stabilizer is ethylene glycol.

5. A method for preparing concrete mineral admixture made from waste incineration ash based on alkali excitation-nano activation according to any one of claims 1 to 4, characterized in that: The following steps are involved: Pre-treating the waste incineration ash to obtain pre-treated waste incineration ash; The pretreated waste incineration ash is first mixed with a nano activator to obtain activated waste incineration ash; mixing an alkali activator with water and stirring to obtain an alkali activator solution; The alkali activator solution, activated waste incineration ash, stabilizer and fly ash are mixed for a second time and stirred to obtain the concrete mineral admixture.

6. The preparation method according to claim 5, characterized in that: The pretreatment includes washing, crushing, screening and grinding the waste incineration ash.

7. The preparation method according to claim 5, characterized in that: The first mixing specifically involves using ultrasonic dispersion to coat the nano activator on the surface of the pretreated waste incineration ash.

8. The preparation method according to claim 7, characterized in that: The frequency of the ultrasonic dispersion is 80-120 khz, and the time is 30-40 minutes.

9. The preparation method according to claim 5, characterized in that: The mass ratio of the alkaline activator to water is 1 to 2:

10.

10. Use of the concrete mineral admixture according to any one of claims 1 to 4 or the concrete mineral admixture obtained by the preparation method according to any one of claims 5 to 9 in concrete.