CN111943554A - Fly ash and preparation method thereof - Google Patents

Abstract

The invention relates to a preparation method of fly ash, which comprises the steps of putting stone powder or a mixture of the stone powder and a grinding aid into a grinding machine for grinding to obtain ground stone powder with more than 325 meshes; and then sequentially putting the steel powder, the obtained ground stone powder, sodium carbonate, sodium sulfate and a water reducing agent into a powder machine, uniformly stirring, and subpackaging to obtain the fly ash. The invention utilizes the waste stone powder to replace the material for producing the fly ash, thereby not only realizing the comprehensive utilization of the waste stone powder, but also reducing the environmental pollution, improving the environment, reducing the preparation cost of the fly ash and reducing the labor cost. The fly ash is prepared from the waste stone powder, the preparation process is simple, and the prepared fly ash can reach the standard of secondary fly ash and has active substances.

Description

Fly ash and preparation method thereof

Technical Field

The invention relates to the field of building materials, in particular to fly ash and a preparation method thereof.

Background

The fly ash mainly refers to tiny ash particles discharged in a combustion process of fuel (mainly coal), the particle size of the tiny ash particles is generally 1-100 mu m, and the tiny solid particles in flue gas ash generated by fuel combustion, such as the tiny ash collected from flue gas of a coal-fired power plant or a thermal power plant, and the like. If the fly ash is not collected and treated, the fly ash causes atmospheric pollution and can foul the river channel when entering water.

Through development and research in China, the fly ash is widely applied to various departments such as construction, building materials, water conservancy and the like. The comprehensive utilization of the fly ash mainly has several aspects, such as conventional utilization of cement raw materials, cement mixed materials, large-scale hydro-junction engineering, pumped concrete and the like, and advanced utilization approaches such as large-volume concrete products, advanced fillers and the like. The fly ash is mainly used for producing fly ash cement, fly ash bricks, fly ash silicate building blocks, fly ash aerated concrete and other building materials, can also be used as agricultural fertilizer and soil conditioner, can be used for recycling industrial raw materials and can be used as environmental materials, and the annual consumption of the whole country exceeds 1 hundred million tons.

In recent years, with the implementation of energy conservation and emission reduction policies in China, the quantity of thermal power plants is less and less, so that the quantity of fly ash is reduced, and the price of fly ash rises.

In addition, in many stone enterprises in China, slurry generated by mixing with water in the stone cutting and processing process is collected, squeezed and dried to form stone powder. At present, a large amount of waste stone powder generated in the stone processing process is basically directly discharged into the environment, and great pollution is caused to the environment. If the waste stone powder can be used for preparing the fly ash, the environmental pollution can be reduced, and the cost of the fly ash can be reduced.

Disclosure of Invention

Therefore, the invention provides the fly ash prepared from waste stone powder, so that the cost of the fly ash is reduced, and the environmental pollution is reduced.

Different from the prior art, the technical scheme provides the fly ash which comprises the following components in parts by weight:

the water reducing agent is a commercially available product purchased from Shanghai Yunji New Material science and technology Limited, and the product brand is FDN-C.

Because the waste stone powder is added into the fly ash, the waste stone powder is fully utilized, the environmental pollution is reduced, and the production cost and the labor cost of the fly ash are reduced.

Meanwhile, the mesh number of the stone powder is more than 325 meshes, the stone powder is easy to dissolve by adding water, the workability of the prepared fly ash is improved, the prepared fly ash is not agglomerated, the performance of active substances can be well exerted, and the hardness and the bonding force of the prepared cement-based material are improved.

As the steel powder is added into the fly ash, the prepared fly ash can improve the fluidity of concrete, prolong the setting time of the concrete, reduce the hydration heat of cement and improve the impermeability and corrosion resistance of the cement.

As sodium carbonate and sodium sulfate are added into the fly ash, active substances in stone powder can be activated, and the hardness and the adhesive force of the prepared cement-based material are improved.

The water reducing agent is added into the fly ash, so that the workability of the fly ash can be improved, the water consumption for preparing cement in the later period is reduced, the compactness and hardness of the prepared cement-based material are improved, and the fluidity of the cement-based material is increased.

Furthermore, the mesh number of the steel powder is 325-350 meshes, so that the prepared fly ash has good solubility and is not easy to agglomerate, and the performance of active substances can be well exerted.

Further, the fly ash also comprises 4-8 parts by weight of grinding aid. The grinding efficiency of the stone powder can be improved by the aid of the grinding aid, and meanwhile, in the fine grinding process of the stone powder, particles are gradually refined, the specific surface area is increased, the surfaces of the particles are charged due to bond breakage, the particles are mutually adsorbed and agglomerated, and the grinding efficiency is reduced. The grinding aid is added, so that the stone powder particles can be prevented from agglomerating, and the flowability of the stone powder is improved, thereby improving the ball milling efficiency and shortening the grinding time.

Further, the grinding aid is triethanolamine or ammonium acetate.

Preferably, the fly ash comprises the following components in parts by weight:

the invention also discloses a preparation method of the fly ash, which comprises the following steps:

1) putting the stone powder or the mixture of the stone powder and a grinding aid into a grinding machine for grinding to obtain ground stone powder with more than 325 meshes;

2) and (2) sequentially putting steel powder, the grinding stone powder obtained in the step 1), sodium carbonate, sodium sulfate and a water reducing agent into a powder machine, uniformly stirring, and subpackaging to obtain the fly ash.

The invention has the beneficial effects that:

1. the waste stone powder is used for replacing the material for producing the fly ash, so that the comprehensive utilization of the waste stone powder is realized, the environmental pollution can be reduced, and the environment is improved.

2. At present, the fly ash can be obtained from flue gas of a coal-fired power plant or a thermal power plant through operations such as collection, separation and the like, the process is more, a large amount of manpower and material resources are needed, and the preparation cost of the fly ash is high. The fly ash is prepared from the waste stone powder, the preparation process is simple, the preparation cost of the fly ash can be reduced, and the labor cost is reduced.

3. The fly ash prepared by the raw materials of stone powder, steel powder and the like can reach the standard of secondary fly ash and has active substances. The fly ash of the invention is particularly suitable for preparing pump concrete, large-volume concrete, impervious structural concrete, sulfate-resistant concrete and soft water erosion-resistant concrete, underground and underwater engineering concrete, mud jacking concrete and roller compacted concrete.

4. The fly ash of the invention reaches the standard of secondary fly ash, can be used as an admixture of mortar or concrete, and the fly ash is added into the concrete to replace part of cement or fine aggregate, thereby not only reducing the cost, but also improving the workability of the concrete, improving the impermeability, gas property, sulfate resistance and chemical corrosion resistance, reducing the hydration heat, improving the high temperature resistance of the concrete, reducing the phenomena of particle separation and water precipitation, reducing the shrinkage and cracking of the concrete and inhibiting the corrosion of stray current to reinforcing steel bars in the concrete.

Detailed Description

In order to explain technical contents, structural features, and objects and effects of the technical means in detail, the following detailed description is given with reference to specific embodiments.

Example 1

Step 1, weighing the following components in parts by weight:

the mesh number of the steel powder is 325-350 meshes;

step 2: putting the stone powder into a grinder for grinding to obtain ground stone powder with more than 325 meshes;

and step 3: and (3) sequentially putting the steel powder, the grinding stone powder obtained in the step (2), sodium carbonate, sodium sulfate and a water reducing agent into a powder machine, uniformly stirring, and subpackaging to obtain the fly ash.

Example 2

Step 1, weighing the following components in parts by weight:

the mesh number of the steel powder is 325-350 meshes.

Step 2: putting the stone powder into a grinder for grinding to obtain ground stone powder with more than 325 meshes;

and step 3: and (3) sequentially putting the steel powder, the grinding stone powder obtained in the step (2), sodium carbonate, sodium sulfate and a water reducing agent into a powder machine, uniformly stirring, and subpackaging to obtain the fly ash.

Example 3

Step 1, weighing the following components in parts by weight:

the mesh number of the steel powder is 325-350 meshes, and the grinding aid is triethanolamine.

Step 2: putting the stone powder and a grinding aid into a grinder for grinding to obtain ground stone powder with more than 325 meshes;

and step 3: and (3) sequentially putting the steel powder, the grinding stone powder obtained in the step (2), sodium carbonate, sodium sulfate and a water reducing agent into a powder machine, uniformly stirring, and subpackaging to obtain the fly ash.

Example 4

Step 1, weighing the following components in parts by weight:

the mesh number of the steel powder is 325-350 meshes, and the grinding aid is triethanolamine.

Step 2: putting the stone powder and a grinding aid into a grinder for grinding to obtain ground stone powder with more than 325 meshes;

and step 3: and (3) sequentially putting the steel powder, the grinding stone powder obtained in the step (2), sodium carbonate, sodium sulfate and a water reducing agent into a powder machine, uniformly stirring, and subpackaging to obtain the fly ash.

Example 5

Step 1, weighing the following components in parts by weight:

the mesh number of the steel powder is 325-350 meshes, and the grinding aid is ammonium acetate.

Step 2: putting the stone powder and a grinding aid into a grinder for grinding to obtain ground stone powder with more than 325 meshes;

and step 3: and (3) sequentially putting the steel powder, the grinding stone powder obtained in the step (2), sodium carbonate, sodium sulfate and a water reducing agent into a powder machine, uniformly stirring, and subpackaging to obtain the fly ash.

Example 6

Step 1, weighing the following components in parts by weight:

the mesh number of the steel powder is 325-350 meshes, and the grinding aid is ammonium acetate.

Step 2: putting the stone powder and a grinding aid into a grinder for grinding to obtain ground stone powder with more than 325 meshes;

and step 3: and (3) sequentially putting the steel powder, the grinding stone powder obtained in the step (2), sodium carbonate, sodium sulfate and a water reducing agent into a powder machine, uniformly stirring, and subpackaging to obtain the fly ash.

The fly ash prepared in the examples 1 to 6 is detected according to the national standard of the technical specification for the application of fly ash concrete (GB/T50146-2014), and specific detection data are shown in the following table 1.

Table 1 examples 1-6 performance test data

TABLE 2 national Standard class I-III fly ash Performance requirements

According to the detection results in the table 1 and the national standard in the table 2, the fly ash prepared by the invention has a screen residue smaller than 24% after passing through a 45-micron sieve, a loss on ignition smaller than 7.5%, a water demand ratio smaller than 102%, does not contain sulfur trioxide, and has the performance reaching the standard of national standard secondary fly ash.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrases "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article, or terminal that comprises the element. Further, herein, "greater than," "less than," "more than," and the like are understood to exclude the present numbers; the terms "above", "below", "within" and the like are to be understood as including the number.

It should be noted that, although the above embodiments have been described herein, the invention is not limited thereto. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by making changes and modifications to the embodiments described herein or by using equivalent structures or equivalent processes performed in the present specification, and are included in the scope of the present invention.

Claims (7)

1. A fly ash, which is characterized in that: the fly ash comprises the following components in parts by weight:

2. a fly ash as claimed in claim 1, wherein: the mesh number of the steel powder is 325-350 meshes.

3. A fly ash as claimed in claim 1, wherein: the mesh number of the stone powder is more than 325 meshes.

4. A fly ash as claimed in claim 1, wherein: the fly ash also comprises 4-8 parts by weight of grinding aid.

5. A fly ash as claimed in claim 4, wherein: the grinding aid is triethanolamine or ammonium acetate.

6. A fly ash as claimed in claim 2, wherein: the fly ash comprises the following components in parts by weight:

7. a method of producing fly ash as claimed in any one of claims 1 to 6, wherein: which comprises the following steps:

1) putting the stone powder or the mixture of the stone powder and a grinding aid into a grinding machine for grinding to obtain ground stone powder with more than 325 meshes;

2) and (2) sequentially putting steel powder, the grinding stone powder obtained in the step 1), sodium carbonate, sodium sulfate and a water reducing agent into a powder machine, uniformly stirring, and subpackaging to obtain the fly ash.