阅读说明：本技术 一种用于磨细粉煤灰的粉体改性激发剂及其制备方法 (Powder modification excitant for pulverized coal ash and preparation method thereof ) 是由 刘炜峰 赵云鹏 于 2021-01-26 设计创作，主要内容包括：本发明属于激发剂及其制备领域,公开了一种用于磨细粉煤灰的粉体改性激发剂及其制备方法,该粉体改性激发剂包括以下制备原料：改性剂、牺牲剂、增强激发剂和硬石膏；其中,改性剂包含木质素磺酸盐、六偏磷酸钠和三聚磷酸钠；该粉体改性激发剂能够充分发挥磨细粉煤灰火山灰效应的潜力,使制备的磨细粉煤灰强度和综合性能有大幅提升,降低磨细粉煤灰的需水量,增强磨细粉煤灰的填充效应,扩大磨细粉煤灰的应用范围和领域,提高磨细粉煤灰生产制备的台时产量,降低磨细粉煤灰制备生产电耗；其制备方法简单,易操作实施。(The invention belongs to the field of excitants and preparation thereof, and discloses a powder modification excitant for pulverized coal ash and a preparation method thereof, wherein the powder modification excitant comprises the following preparation raw materials: modifiers, sacrificial agents, reinforcing excitants and anhydrite; wherein the modifier comprises lignosulfonate, sodium hexametaphosphate and sodium tripolyphosphate; the powder modification excitant can fully exert the potential of the volcanic ash effect of the milled fly ash, greatly improve the strength and the comprehensive performance of the prepared milled fly ash, reduce the water requirement of the milled fly ash, enhance the filling effect of the milled fly ash, expand the application range and the field of the milled fly ash, improve the hourly output of the production and the power consumption of the preparation of the milled fly ash; the preparation method is simple and easy to operate and implement.)

1. A powder modification excitant for pulverized coal ash is characterized by comprising the following preparation raw materials: modifiers, sacrificial agents, reinforcing excitants and anhydrite.

2. The powder modification stimulant for milled fly ash according to claim 1, wherein the modifier comprises lignosulfonate, sodium hexametaphosphate and sodium tripolyphosphate.

3. The powder modification stimulant for milled fly ash according to claim 2, wherein the lignosulfonate is calcium lignosulfonate; the molecular weight of the lignosulfonate is 800-10000, and the reducing sugar is less than or equal to 30%.

4. The powder modification excitant for milled fly ash according to claim 1, wherein the sacrificial agent is sodium thiosulfate.

5. The powder modification excitant for milled fly ash according to claim 1, wherein the reinforcing excitant is anhydrous sodium sulphate.

6. The powder modification excitant for ground fly ash according to claim 2, wherein the sodium hexametaphosphate is technical grade, P₂O₅Not less than 68 percent; the sodium tripolyphosphate is of industrial grade, and the content is more than or equal to 96 percent.

7. The powder modifying excitant for ground fly ash according to claim 1, wherein 0.045mm screen residue of anhydrite is 20% to 40%, SO₃More than or equal to 50 percent and less than or equal to 4 percent of crystal water, which is one or two of natural anhydrite or industrial byproduct gypsum.

8. The powder modification excitant for milled fly ash according to claim 2, wherein the amount of the raw materials is: 6.2-15.5% of modifier, 10-20% of sacrificial agent, 20-30% of reinforcing excitant and 34.5-63.8% of anhydrite.

9. The powder modification excitant for pulverized coal ash as claimed in claim 8, wherein the modifier comprises 1-5% of lignosulfonate, 5-10% of sodium hexametaphosphate and 0.2-0.5% of sodium tripolyphosphate.

10. A preparation method of a powder modification excitant for milled fly ash is characterized in that the powder modification excitant for milled fly ash based on claim 2 comprises the following steps:

step 1, mixing and grinding a sacrificial agent, an enhanced excitant, sodium hexametaphosphate, sodium tripolyphosphate and anhydrite to obtain a mixture with the surface area of 260-320 m²A mixture of/kg;

and 2, fully mixing and uniformly stirring the mixture and the lignosulfonate to obtain the composite material.

Technical Field

The invention relates to an excitant and the preparation field thereof, in particular to a powder modification excitant for pulverized coal ash and a preparation method thereof.

Background

The method has the advantages of dissolving the industrial waste residue, realizing the resource utilization of the industrial waste residue, realizing green development, developing the application value of the pulverized coal ash by grinding the pulverized coal ash, and improving the technical level of the application of the pulverized coal ash. The pulverized coal ash is used as important inorganic non-metal raw material for cement, high-performance and ultrahigh-performance concrete and other special engineering. The pulverized coal ash can fully exert the potential of the volcanic ash effect of the pulverized coal ash, improve the strength of concrete, enhance the micro aggregate filling effect of the pulverized coal ash, improve the workability of the concrete, save the cost and realize the purposes of energy conservation, consumption reduction and green low-carbon development.

The low activity and early strength of the original fly ash result in limited use of fly ash in large quantities. The original fly ash has low economic added value, and the fly ash prepared by grinding and added with the modified excitant has greatly improved volcanic ash performance, filling performance, surface performance and the like, becomes a high-strength high-performance mineral admixture and mineral admixture, improves the added value of the original fly ash, and greatly improves the resource utilization of the original fly ash.

The powder modification excitant can improve the activity of the milled fly ash and increase the early and later strength of the milled fly ash by participating in the preparation of the milled fly ash and adding the milled fly ash into the milled fly ash; the water demand of the pulverized coal ash is reduced; the filling effect of the pulverized fly ash is enhanced; the application range and the field of the pulverized coal ash are expanded; the machine hour yield of the production of the milled fly ash is improved, and the power consumption of the production of the milled fly ash is reduced. According to the principle of usability, constructability and economy of the pulverized fly ash, the powder modification excitant meeting the requirements of the high-strength high-performance pulverized fly ash is researched and developed by modifying and exciting the pulverized fly ash, and has significant meaning. Therefore, it is an urgent technical problem to develop a modifying activator capable of improving the activity and comprehensive performance of the pulverized coal ash, and reducing the comprehensive cost of concrete.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a powder modification excitant for pulverized coal ash and a preparation method thereof, wherein the powder modification excitant can fully exert the potential of the volcanic ash effect of the pulverized coal ash, greatly improve the strength and the comprehensive performance of the prepared pulverized coal ash, reduce the water demand of the pulverized coal ash, enhance the filling effect of the pulverized coal ash, expand the application range and the field of the pulverized coal ash, improve the hourly output of the production and the preparation of the pulverized coal ash, and reduce the power consumption of the preparation and the production of the pulverized coal ash; the preparation method is simple and easy to operate and implement.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme.

The powder modification excitant for the milled fly ash comprises the following preparation raw materials: modifiers, sacrificial agents, reinforcing excitants and anhydrite.

Preferably, the modifier comprises lignosulfonate, sodium hexametaphosphate and sodium tripolyphosphate.

Further preferably, the lignosulfonate is calcium lignosulfonate.

Further preferably, the molecular weight of the lignosulfonate is 800-10000, and the reducing sugar is less than or equal to 30%.

Preferably, the sacrificial agent is sodium thiosulfate.

Further preferably, the sodium thiosulfate is industrial grade, contains 5 crystal waters and has a content of not less than 95%.

Preferably, the enhancer activator is anhydrous sodium sulphate.

Further preferably, the anhydrous sodium sulphate is in industrial grade, and the content is more than or equal to 99%.

Preferably, the sodium hexametaphosphate is technical grade, P₂O₅Not less than 68 percent; the sodium tripolyphosphate is of industrial grade, and the content is more than or equal to 96 percent.

Preferably, the 0.045mm screen residue of the anhydrite is 20 to 40 percent, and the SO₃More than or equal to 50 percent and less than or equal to 4 percent of crystal water, which is one or two of natural anhydrite or industrial byproduct gypsum.

Preferably, the raw materials are used in the following amounts: 6.2-15.5% of modifier, 10-20% of sacrificial agent, 20-30% of reinforcing excitant and 34.5-63.8% of anhydrite.

Further preferably, the modifier comprises 1-5% of lignosulfonate, 5-10% of sodium hexametaphosphate and 0.2-0.5% of sodium tripolyphosphate.

(II) a preparation method of a powder modification excitant for fine fly ash grinding, which comprises the following steps:

step 1, mixing and grinding a sacrificial agent, an enhanced excitant, sodium hexametaphosphate, sodium tripolyphosphate and anhydrite to obtain a mixture with the surface area of 260-320 m²A mixture of/kg;

and 2, fully mixing and uniformly stirring the mixture and the lignosulfonate to obtain the composite material.

Compared with the prior art, the invention has the beneficial effects that:

1) the powder modification excitant can improve the activity of the milled fly ash and increase the early and later strength of the milled fly ash by participating in the production preparation of the milled fly ash and adding the milled fly ash into the milled fly ash; the water demand of the pulverized coal ash is reduced; the filling effect of the pulverized fly ash is enhanced; the application range and the field of the pulverized coal ash are expanded; the machine hour yield of the production and preparation of the pulverized fly ash is improved, and the power consumption of the production and preparation of the pulverized fly ash is reduced.

2) The strength of concrete prepared by using the pulverized fly ash which is added with the powder modification excitant and participates in the grinding preparation is improved; under the condition of ensuring that the state of the fresh concrete mixture is not changed, the water consumption of single concrete is reduced; the concrete has excellent working performance, pumping performance and construction performance; the powder modification excitant has good adaptability with polycarboxylic acid and naphthalene additives; the concrete prepared by the pulverized fly ash ground by the modified excitant has better durability and microcosmic performance.

Drawings

The invention is described in further detail below with reference to the figures and specific embodiments.

FIG. 1 is a cumulative distribution diagram of the particle size of the pulverized fly ash obtained by using the powder modifying excitant of example 3.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.

Example 1

A powder modification excitant for pulverized coal ash comprises the following raw materials by mass percent: 7.2 percent of modifier, 25 percent of sacrificial agent, 10 percent of reinforcing excitant and 57.8 percent of anhydrite carrier. Wherein the modifier comprises 2% of lignosulfonate, 5% of phosphate 1# and 0.2% of phosphate 2 #; the reinforcing excitant is anhydrous sodium sulphate, and the sacrificial agent is sodium thiosulfate; the anhydrite carrier is anhydrite.

Wherein the lignosulfonate is calcium lignosulfonate, has a molecular weight of 1000-8000, and contains reducing sugar 20%. Phosphate 1# is sodium hexametaphosphate, technical grade, P₂O₅The content was 70%. The phosphate No. 2 is sodium tripolyphosphate, is of industrial grade, and has a content of 98%. The anhydrous sodium sulphate is of industrial grade, and the content is more than or equal to 99.2 percent. The sodium thiosulfate is industrial grade and contains 5 crystal waters with a content of 96%. 30% of anhydrite with 0.045mm screen residue and SO₃The content is 52 percent, the crystal water is 3 percent, and the gypsum is natural anhydrite.

The preparation method of the powder modification excitant for the pulverized coal ash comprises the following steps:

step 1, mixing the anhydrous sodium sulphate, the sodium thiosulfate, the phosphate 1#, the phosphate 2# and the anhydrite according to the formula dosage, and grinding the mixture in a grinding machine until the specific surface area is 260-320 m²Kg, to give a mixture.

And 2, fully mixing and uniformly stirring the mixture and lignosulfonate according to the formula dosage to obtain the powder modification excitant FJF1 for the pulverized coal ash.

Example 2

A powder modification excitant for pulverized coal ash comprises the following raw materials by mass percent: 8.3 percent of modifier, 20 percent of sacrificial agent, 15 percent of reinforcing excitant and 56.7 percent of anhydrite carrier. Wherein the modifier comprises 1% of lignosulfonate, 7% of phosphate 1# and 0.3% of phosphate 2 #; the reinforcing excitant is anhydrous sodium sulphate, and the sacrificial agent is sodium thiosulfate; the anhydrite carrier is anhydrite.

Wherein the lignosulfonate is calcium lignosulfonate, has a molecular weight of 1000-5000 and contains reducing sugar 25%. Phosphate 1# is sodium hexametaphosphate, technical grade, P₂O₅The content was found to be 75%. The phosphate No. 2 is sodium tripolyphosphate, is of industrial grade, and has a content of 97%. The anhydrous sodium sulphate is of industrial grade, and the content is more than or equal to 99.5 percent. The sodium thiosulfate is industrial grade, contains 5 crystal water and has a content of 97 percent. 20% of anhydrite with 0.045mm screen residue and SO₃The content is 50 percent, the crystal water is 2 percent, and the gypsum is natural anhydrite.

The preparation method of the powder modification excitant for the pulverized coal ash comprises the following steps:

step 1, mixing the anhydrous sodium sulphate, the sodium thiosulfate, the phosphate 1#, the phosphate 2# and the anhydrite according to the formula dosage, and grinding the mixture in a grinding machine until the specific surface area is 260-320 m²Kg, to give a mixture.

And 2, fully mixing and uniformly stirring the mixture and lignosulfonate according to the formula dosage to obtain the powder modification excitant FJF2 for the pulverized coal ash.

Example 3

A powder modification excitant for pulverized coal ash comprises the following raw materials by mass percent: 15.5% of modifier, 30% of sacrificial agent, 20% of reinforcing excitant and 34.5% of anhydrite carrier. Wherein, the modifier comprises 5 percent of lignosulfonate, 10 percent of phosphate 1# and 0.5 percent of phosphate 2 #; the reinforcing excitant is anhydrous sodium sulphate, and the sacrificial agent is sodium thiosulfate; the anhydrite carrier is anhydrite.

Wherein the lignosulfonate is calcium lignosulfonate, has a molecular weight of 1000-10000 and contains reducing sugar of 30%. Phosphate 1# is sodium hexametaphosphate, technical grade, P₂O₅The content was 78%. The phosphate No. 2 is sodium tripolyphosphate, is of industrial grade, and has a content of 99%. The anhydrous sodium sulphate is of industrial grade, and the content is more than or equal to 99.5 percent. The sodium thiosulfate is industrial grade, contains 5 crystal waters and has a content of 98%. 0.045mm of anhydrite with the screen residue of 40 percent and SO₃The content of the gypsum is 54 percent, the crystal water is 4 percent, and the gypsum is natural anhydrite.

The preparation method of the powder modification excitant for the pulverized coal ash comprises the following steps:

step 1, mixing the anhydrous sodium sulphate, the sodium thiosulfate, the phosphate 1#, the phosphate 2# and the anhydrite according to the formula dosage, and grinding the mixture in a grinding machine until the specific surface area is 260-320 m²Kg, to give a mixture.

And 2, fully mixing and uniformly stirring the mixture and lignosulfonate according to the formula dosage to obtain the powder modification excitant FJF3 for the pulverized coal ash.

The specific functions of the raw materials in the powder modification excitant for the pulverized fly ash are as follows:

the anhydrous sodium sulphate is added into the pulverized fly ash and participates in the preparation of the fly ash, so that the early strength of the pulverized fly ash can be improved; the activity of the fly ash is improved, the filling effect of the fly ash is enhanced, the hydration of crystal nuclei can be promoted in the early stage, the drying shrinkage can be reduced in the later stage, and the compactness and the mechanical property of the concrete are improved.

The sodium thiosulfate is added into the ground fine coal powder and participates in the preparation of the coal ash, so that the adsorption of cement particles to an additive can be reduced, the unit water consumption is reduced, the fluidity of a mixture is improved, and the early strength of concrete is improved; the filling effect is exerted to reduce the porosity of the concrete and improve the fluidity of the concrete.

The lignosulfonate is added into the pulverized coal ash, so that the grinding efficiency of the pulverized coal ash can be improved, the particle composition of the pulverized coal ash is improved, the dispersibility of the pulverized coal ash in concrete is enhanced, the viscosity of the concrete is reduced, and the early and later strength of the concrete is improved.

The phosphate 1# is added into the pulverized coal ash and participates in the preparation of the pulverized coal ash, so that the grinding efficiency of the pulverized coal ash is improved, and the later strength of the concrete is improved.

The phosphate 2# is added into the pulverized coal ash and participates in the preparation of the pulverized coal ash, so that the grinding efficiency of the pulverized coal ash is improved, the fluidity of the mixture is improved, and the later strength of the concrete is improved.

The anhydrite can keep the better dispersibility of the modifying excitant, improve the dispersion uniformity of the ground fly ash, improve the fluidity of the concrete, accelerate the hydration process of the concrete and improve the early strength and the durability of the concrete.

Test 1

The powder modification accelerators for fly ash obtained in examples 1 to 3 were subjected to performance tests, and the results are shown in table 1.

TABLE 1 table of the performance test results of the powder modifying excitant used for grinding fly ash

Test 2

The powder modification excitant for grinding the fly ash prepared in the above embodiments 1 to 3 is added to the fly ash grinding process from the grinding head of the mill process system according to the mixing amount of 1.5% of the mass of the fly ash, and the fly ash is ground by a phi 4.2 × 13m ball mill to prepare the ground fly ash. The specific surface area, the water demand ratio and the activity index of 3 kinds of the prepared fly ash to which the powder modification excitant of the present invention was applied and the fly ash to which the powder modification excitant of the present invention was not applied (comparative example 1) were respectively tested, and the test results are shown in table 2; the indexes such as activity index, water demand ratio, specific surface area and the like of the pulverized coal ash are tested by referring to GB/T1596-2017 fly ash for cement and concrete and GB/T18736-2017 mineral admixture for high-strength and high-performance concrete.

Table 2 table of physical property test results of applying powder modifying excitant to grinding for preparing pulverized coal ash

Numbering	Specific surface area (m)2/kg)	Water demand ratio (%)	Activity index (%)
				Comparative example 1	490	102	84
FJF 1-doped pulverized coal ash	495	95	90
				FJF 2-doped pulverized coal ash	518	95	90
FJF 3-doped pulverized coal ash	510	93	92

As can be seen from Table 2, the specific surface area of examples 1 to 3 is increased as compared with comparative example 1, the water demand ratio is significantly reduced, and the activity index is improved.

Test 3

According to the concrete mixing ratio designed and specified in table 3, 3 kinds of pulverized coal ash prepared in the test 2 by applying the powder modification excitant of the invention are respectively mixed with gravels (crushed stones, machine-made sands and river sands), cement, an additive (a naphthalene additive with the solid content of 40-45 percent, wherein the solid content of the additive comprises 38-42 percent of high-efficiency water reducing agent, 0.02-0.04 percent of air entraining agent, 2.0-2.5 percent of sodium gluconate and 55.5-59.0 percent of water) and water, the mixing is completed, the slump and the expansion degree of fresh concrete are measured, the slump and the expansion degree are measured after the mixture is placed for 1h, then the setting time and the like are measured, the rest concrete is molded into 100 × 100 × 100 test blocks, the compressive strength of 7d and 28d is measured, and the test results are shown in table 4; the concrete setting time of the fresh concrete material in the embodiment is tested by referring to GB/T51003-2014 mineral admixture application technical Specification and GB/T50080-2002 common concrete mixture performance test method Standard; the fresh concrete material of the embodiment is subjected to concrete compressive strength test by referring to GB/T50081-2002 Standard test method for mechanical properties of ordinary concrete.

TABLE 3 concrete mixing proportion materials consumption Scale kg/m³

In table 3, the water usage was adjusted according to the workability of freshly mixed concrete.

TABLE 4 Performance test results of concrete with different fly ashes

As can be seen from table 4, the concrete strength of the pulverized fly ash prepared by using the powder modified activator in examples 1 to 3 after being used in concrete is greatly improved in 7d and 28 days compared with that of the standard (pulverized fly ash prepared by not using the activator), the state of a concrete mixture is better than that of the standard concrete, and the setting time is shorter than that of the standard concrete; compared with the comparative example (the commercially available pulverized fly ash, the pulverized fly ash after the use of the market excitant), the concrete strength of the examples 1-3 is greatly improved in 7d and 28 days, and the setting time is obviously shortened compared with that of the comparative example concrete.

Test 4

The powder modification excitant prepared in example 3 is added into the fly ash grinding process from a grinding head of a mill process system according to the mixing amount of 1.5% of the mass of the fly ash, and is ground by a phi 4.2 x 13m ball mill to prepare the ground fly ash, wherein the sieve residue of a 45-micron square-hole sieve is less than 12%, and the particle size distribution curve is shown in figure 1.

In fig. 1, the results of the particle size distribution of the pulverized fly ash are: d10 ═ 1.8 μm, D50 ═ 10.5 μm, D90 ═ 28.5 μm, and the content of not more than 3 μm was 17.1%, and the range of particle size distribution was satisfactory for the pulverized coal ash after the use of the powder modifying activator.

In conclusion, the powder modification excitant for the milled fly ash, which is disclosed by the invention, has the following seven characteristic advantages: (1) the strength of the concrete prepared by the pulverized fly ash added with the powder modification excitant is improved by 12-15% compared with that of the standard concrete; (2) under the condition of ensuring that the state of the fresh concrete mixture is not changed, the water consumption of single concrete is reduced by 8-10 kg/m³(ii) a (3) The concrete has excellent working performance, pumping performance and construction performance; (4) the powder modification excitant and the additive have good adaptability; (5) the concrete prepared by the pulverized fly ash added with the powder modification excitant has better durability and microcosmic performance; (6) the application range and the field of the pulverized coal ash can be enlarged; (7) the machine hour yield of the production of the milled fly ash can be improved, and the power consumption of the production of the milled fly ash can be reduced.

Although the present invention has been described in detail in this specification with reference to specific embodiments and illustrative embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made thereto based on the present invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.