阅读说明：本技术 超细改性磷渣粉及混凝土用超细复合掺合料 (Superfine modified phosphorus slag powder and superfine composite admixture for concrete ) 是由 纪宪坤 肖蓟 刘勇 王海龙 程福星 万鹏程 于 2020-05-13 设计创作，主要内容包括：本发明公开了一种超细改性磷渣粉及混凝土用超细复合掺合料,属于混凝土掺合料生产技术领域,所述超细改性磷渣粉由磷渣与改性剂按质量配比95～99：1～5混合粉磨至比表面积为600～650m<Sup>2</Sup>/kg,于干燥环境中均化并静置1d后所得；所述改性剂由消石灰粉、硫酸铝及异辛醇组成,所述消石灰粉、硫酸铝与异辛醇按质量配比计为1：1～4：0.05～0.2。本发明改性剂通过消石灰粉、硫酸铝和异辛醇协同作用,可有效固化磷渣中的可溶性P。经超细化及改性处理之后磷渣中的可溶性P降至0.5％以下,消除了磷渣的缓凝特性,并极大的提升磷渣的反应活性。使用该超细改性磷渣粉复合改性火山灰质材料、超细填充组分及激活剂与保水剂,能够制备适用于混凝土中的超细复合掺合料。(The invention discloses superfine modified phosphorus slag powder and a superfine composite admixture for concrete, belonging to the technical field of concrete admixture production, wherein the superfine modified phosphorus slag powder is prepared from phosphorus slag and a modifier according to the mass ratio of 95-99: 1-5 mixing and grinding until the specific surface area is 600-650 m 2 /kg, homogenizing in a dry environment and standing for 1 d; the modifier consists of slaked lime powder, aluminum sulfate and isooctyl alcohol, wherein the slaked lime powder, the aluminum sulfate and the isooctyl alcohol are 1: 1-4: 0.05 to 0.2. The modifier can effectively solidify the soluble P in the phosphorus slag through the synergistic effect of the slaked lime powder, the aluminum sulfate and the isooctyl alcohol. After the superfine treatment and the modification treatment, the soluble P in the phosphorus slag is reduced to be less than 0.5 percent, the delayed coagulation characteristic of the phosphorus slag is eliminated, and the reactivity of the phosphorus slag is greatly improved. Using the ultrafine modificationThe phosphorus slag powder composite modified pozzolanic material, the superfine filling component, the activator and the water-retaining agent can be used for preparing superfine composite admixture suitable for concrete.)

1. The superfine modified phosphorus slag powder is characterized by comprising 95-99 mass percent of phosphorus slag and a modifier: 1-5 mixing and grinding until the specific surface area is 600-650 m²/kg, homogenizing in a dry environment and standing for 1 d;

the modifier consists of slaked lime powder, aluminum sulfate and isooctyl alcohol, wherein the slaked lime powder, the aluminum sulfate and the isooctyl alcohol are 1: 1-4: 0.05 to 0.2.

2. The ultrafine modified phosphorus slag powder according to claim 1, wherein the phosphorus slag and the modifier are mixed and ground into powder with a specific surface area of 600-650 m according to a mass ratio of 97:3²/kg, homogenizing in a dry environment and standing for 1 d;

the modifier consists of slaked lime powder, aluminum sulfate and isooctyl alcohol, wherein the slaked lime powder, the aluminum sulfate and the isooctyl alcohol are 1: 2: 0.1.

3. the ultrafine composite admixture for concrete containing the ultrafine modified phosphorous slag powder as claimed in claim 1, which comprises the following components in parts by weight: 35-45 parts of superfine modified phosphorous slag powder, 45-55 parts of modified pozzolanic material, 3-6 parts of superfine filling component, 0-7.2 parts of activator and 0-1.8 parts of water-retaining agent.

4. The ultrafine composite admixture for concrete according to claim 3, comprising the following components in parts by weight: 40 parts of superfine modified phosphorous slag powder, 49 parts of modified volcanic ash material, 5 parts of superfine filling component, 4.8 parts of activator and 1.2 parts of water-retaining agent.

5. The ultrafine composite admixture for concrete according to claim 3, wherein the modified pozzolanic material is a mixture of slag and aluminum slag in a mass ratio of 9:1, and the mixture is ground to a specific surface area of more than 1000m²After the/kg, the material is obtained by surface modification by using titanate coupling agent accounting for 0.5 percent of the total mass of the pozzolanic material.

6. The ultrafine composite admixture for concrete according to claim 3 wherein the ultrafine filler component is nano-active calcium carbonate having a maximum particle size of <0.1 μm.

7. The ultrafine composite admixture for concrete according to claim 3, wherein the activator is phosphogypsum, and the phosphogypsum is washed with water and calcined at 500 ℃ for 30min and then ground into powder with specific surface area of more than 300m²/kg。

8. The ultrafine composite admixture for concrete as claimed in claim 3, wherein said water-retaining agent is sodium polyacrylate.

9. The method for preparing the ultrafine composite admixture for concrete according to any one of claims 3 to 8, comprising the steps of:

s1, mixing the phosphorus slag, the slaked lime powder and the aluminum sulfate, dripping isooctanol into the mixture, and grinding the mixture until the specific surface area is not less than 300m²And/kg, then transferring the mixture into an air flow mill until the specific surface area is 600-650 m²/kg, homogenizing and standing for 1d to obtain superfine powderModifying phosphorus slag powder;

s2, washing the activator with water, calcining at 500 ℃ for 30min, and grinding to a specific surface area of more than 300m²/kg, then mixing with a water-retaining agent to obtain a mixture of the water-retaining agent and an activating agent;

s3, uniformly mixing the superfine modified phosphorous slag powder, the modified pozzolanic material, the superfine filling component, the water-retaining agent and the activator according to the mass ratio to obtain the superfine composite admixture.

10. The method of preparing an ultra-fine composite admixture for concrete according to claim 9, wherein the modified pozzolanic material is prepared by: grinding the pozzolanic material to a specific surface area of not less than 300m²/kg, then transferring into a jet mill until the specific surface area is not less than 1000m²And/kg, adding titanate coupling agent accounting for 0.5 percent of the total mass of the pozzolanic material for surface modification to obtain the modified pozzolanic material.

Technical Field

The invention relates to the technical field of concrete admixture production, in particular to superfine modified phosphorus slag powder and a superfine composite admixture for concrete.

Background

In recent years, with the rapid development of the nation and the society, the quantity and quality requirements of various civil and industrial buildings and municipal works are gradually improved, and the performance requirements of various construction requirements and construction environments on concrete are also gradually complicated, so that it is necessary to improve the concrete production technology to match the gradually complicated performance requirements. The concrete admixture is used for improving the performance of concrete, saving water, adjusting the strength grade of the concrete, and adding natural or artificial powdery mineral substances capable of improving the performance of the concrete during the mixing of the concrete. At present, high-quality mineral admixtures in China mainly comprise I-grade and II-grade fly ash, S95-grade mineral powder and silica fume, but the application of the admixtures in concrete has defects, such as low activity of the fly ash in the early stage of hydration, low early strength of the concrete, easy carbonization, easy peeling off of the surface skin in a freeze-thaw environment and the like; the mineral powder is easy to make concrete mixture bleed, and simultaneously, the shrinkage and cracking risks of the concrete are increased; the silica fume has high hydration heat and large water demand, and the risk of concrete cracking is increased; other materials such as steel slag, lithium slag, stone powder, phosphorous slag and the like have different defects of poor grinding degree, poor stability, high water demand, low activity, delayed coagulation and the like, and have lower utilization rate and utilization amount in admixture.

The Chinese patent No. CN201910626467.X discloses a titanium slag powder-phosphorus slag powder composite admixture, a preparation method and an application method thereof, wherein the composite admixture comprises the following components in percentage by mass: 10-30 parts of slag powder, 10-30 parts of titanium-containing slag powder, 20-40 parts of phosphorus slag powder, 15-40 parts of silica fume and 1-5 parts of excitant; the slag powder is water-quenched blast furnace slag powder; the phosphorus slag powder is granulated electric furnace phosphorus slag powder. However, the admixture contains phosphorus slag, and after the phosphorus slag is ground, a large amount of soluble P is released, so that the phosphorus slag can easily react with surrounding calcium ions to form a calcium phosphate-like structure, a hydroxyapatite structure is formed on the surface of phosphorus slag particles, so that the hydration is hindered, the slow setting is caused, and the early strength of the concrete is slightly low due to the prolonged setting time, so that the admixture can achieve higher strength in a longer time.

In order to improve the activity of the phosphorus slag and eliminate the influence of harmful components in the phosphorus slag, a great deal of research is carried out in the last decade. Chinese patent No. CN201610873506.2 discloses a modified activated phosphorus slag, a preparation method thereof, and modified activated phosphorus slag cement and concrete modified activated phosphorus slag, which comprises the following components: an active agent and phosphorous slag; the mass ratio of the active agent to the phosphorous slag is 0.5-1: 10; the water content in the phosphorous slag is less than 2 percent of the weight of the phosphorous slag; the weight ratio of the active agent components is as follows: 50-70 parts of carbide slag, and aluminum sulfate slag: 0-40 parts of red mud: 0-40 parts of high-alumina fly ash: 0-30, gypsum: 20-30 parts of anhydrous calcium sulphoaluminate mineral: 0 to 30 parts. The invention eliminates P to a certain extent₂O₅But only P on the surface of the slag₂O₅For P in the interior of the phosphorus slag particles₂O₅The removal effect is limited; secondly, raw materials of the modified activated phosphorus slag, such as the raw materials of the carbide slag, the red mud and the like, contain a large amount of calcium oxide, so that certain hidden trouble is brought to the volume stability of the concrete, and the later strength of the concrete is inhibited from increasing.

Disclosure of Invention

The invention aims at the existing technical problems, develops an ultrafine modified phosphorus slag powder and provides an ultrafine composite admixture for concrete containing the ultrafine modified phosphorus slag powder; the invention can effectively solidify the soluble P in the phosphorus slag through the synergistic effect of the slaked lime powder, the aluminum sulfate and the isooctanol, and the soluble P in the phosphorus slag after the modification treatment is reduced to be less than 0.5 percent, thereby eliminating the delayed coagulation property of the phosphorus slag and greatly improving the reaction activity of the phosphorus slag; so that the superfine modified phosphorus slag powder can be used for preparing superfine composite admixture for concrete with better performance.

The technical purpose of the invention is realized by the following technical scheme:

the superfine modified phosphorus slag powder is prepared from phosphorus slag and a modifier according to the mass ratio of 95-99: 1-5 mixing and grinding until the specific surface area is 600-650 m²/kg，Homogenizing in dry environment and standing for 1 d;

the modifier consists of slaked lime powder, aluminum sulfate and isooctyl alcohol, wherein the slaked lime powder, the aluminum sulfate and the isooctyl alcohol are 1: 1-4: 0.05 to 0.2.

Adopt above-mentioned technical scheme: the process of superfine grinding can lead Si-O, Al-O bonds in a large amount of glass bodies contained in the phosphorus slag to be broken, so that the phosphorus slag has higher reaction activity, can promote the hydration process and improve the gelling activity of the phosphorus slag; however, although the activity (especially the later activity) of the phosphorus slag is greatly improved after the ultrafine grinding, a large amount of soluble P (P) can be released along with the crushing of powder particles₂O₅) And the substances have strong retarding effect on the cement-based materials, and finally result in the low initial activity of the superfine phosphorus slag admixture. Therefore, the P in the phosphorous slag needs to be solidified by using a modifier₂O₅. When slaked lime powder, aluminum sulfate and phosphorus slag in the modifier are ground together, soluble P on the surface layer of the superfine phosphorus slag powder₂O₅Calcium phosphate, aluminum phosphate and the like are generated by solidification, so that the delayed coagulation effect of the soluble P on the cement-based material is greatly reduced; the isooctanol permeates into the micropores of the powder in the process of co-grinding, and is not solidified with the P in the powder under the high-temperature environment of grinding₂O₅The esterification is generated by the reaction, so that the phosphorus fixation efficiency of the modifier is further improved, and the content of soluble P in the phosphorus slag is reduced to be less than 0.5%. Namely, the retarding property of the phosphorous slag is eliminated through grinding and treatment by the modifier, the early hydrolysis of the superfine modified phosphorous slag powder can be promoted, and the gelling activity of the phosphorous slag is improved.

Further, the phosphorus slag and the modifier are mixed and ground into powder according to the mass ratio of 97:3 until the specific surface area is 600-650 m²/kg, homogenizing in a dry environment and standing for 1 d;

the modifier consists of slaked lime powder, aluminum sulfate and isooctyl alcohol, wherein the slaked lime powder, the aluminum sulfate and the isooctyl alcohol are 1: 2: 0.1.

in the modifier, the content of slaked lime powder and aluminum sulfate is too high, on one hand, calcium phosphate, aluminum phosphate and the like generated by reaction in the grinding process are deposited on the surface of the superfine phosphorus slag powder and can block micropores of the superfine phosphorus slag powder, so that the solidification of soluble P in the superfine phosphorus slag powder is influenced, and the solidification efficiency is reduced, on the other hand, the improvement of the phosphorus-fixing component tends to reduce the content of the active component phosphorus slag powder, so that the hydration activity of the superfine modified phosphorus slag powder and the superfine composite admixture is reduced. And the content of the modifier is too low, which causes incomplete reaction of soluble P on the surface layer of the superfine phosphorus slag powder and reduces the curing efficiency, so that the preferred mass ratio of the slaked lime powder, the aluminum sulfate and the isooctyl alcohol is 1: 1-2: 0.05-0.2, wherein within the mass ratio range, the soluble P on the surface layer and inside the superfine modified phosphorous slag powder can be well solidified, and more preferably, the mass ratio of the slaked lime powder, the aluminum sulfate and the isooctyl alcohol is 1: 2: 0.1.

an ultrafine composite admixture for concrete comprises the following components in parts by weight: 35-45 parts of superfine modified phosphorous slag powder, 45-55 parts of modified pozzolanic material, 3-6 parts of superfine filling component, 0-7.2 parts of activator and 0-1.8 parts of water-retaining agent.

Adopt above-mentioned technical scheme: the phosphorus slag has a large amount of amorphous glass bodies, can be secondarily hydrated with calcium hydroxide generated by hydration of cement in a cement-based material to generate a gel hydration product, provides higher strength for hardening cement stone, can greatly improve the later stage hydration activity of the hardened cement stone through superfine treatment, removes soluble P to the maximum extent through modification treatment, effectively improves the retarding effect of superfine phosphorus slag powder, and can be used as a high-activity admixture.

The pozzolanic material has a certain pozzolanic activity, and can be mixed with cement hydration products Ca (OH)₂The reaction generates hydration products such as C-S-H gel and the like. And is subjected to ultra-fine grinding to 1000m²After the concentration is higher than the concentration of the superfine modified phosphorous slag powder, the gelling activity is greatly improved, and the superfine modified phosphorous slag powder can provide strength guarantee for cement-based materials.

The superfine filling component nano active calcium carbonate is doped, so that the filling and compacting effects can be exerted, the performance of a concrete mixture is improved, and the compaction degree of the concrete is increased; simultaneously, the cement mineral C can also play an accelerating effect and promote the cement mineral C₃The initial hydration of S increases the early strength of the cement-based material.

After washing and high-temperature calcining, the activator phosphogypsum has a greatly weakened retarding effect on cement-based materials, and gypsum components in the activator can excite the gelling activity of phosphorous slag and pozzolanic materials, so that the effect of enhancing the strength of the cement-based materials is achieved.

The water-retaining agent sodium polyacrylate is a powdery chemical product with good water-retaining property, and can reduce the loss of water in concrete by being mixed into admixture, thereby providing better initial-stage maintenance effect for the concrete.

Further, the paint comprises the following components in parts by weight: 40 parts of superfine modified phosphorous slag powder, 49 parts of modified volcanic ash material, 5 parts of superfine filling component, 4.8 parts of activator and 1.2 parts of water-retaining agent.

Further, the modified pozzolanic material is prepared by mixing and grinding slag and aluminum slag according to the mass ratio of 9:1 until the specific surface area is more than 1000m²After the/kg, the material is obtained by surface modification by using titanate coupling agent accounting for 0.5 percent of the total mass of the pozzolanic material. The volcanic ash material is obtained by mixing and grinding slag and aluminum slag which are slightly weak in activity and low in price and are easy to obtain, the activity of the material is slightly weak, and the activity of the volcanic ash is greatly improved through the slag and the aluminum slag which are subjected to ultrafine grinding. On one hand, the specific surface area of the raw material is increased, the contact area of the powder and water can be increased, and the reaction rate is increased; on the other hand, the superfine grinding can promote the distortion of the primary crystal lattice of the powder material, so that Si-O bonds and Al-O bonds are broken, and the reaction degree is improved. After grinding, the particle size of the pozzolanic material is small and easy to agglomerate; therefore, the 0.5% titanate coupling agent is doped into the pozzolanic material, and the powder stirrer is used for stirring for half an hour to modify the surface of the powder, so that the agglomeration phenomenon of the pozzolanic material with high specific surface area can be eliminated, the dispersion degree of the pozzolanic material in concrete is improved, and the activity of the modified pozzolanic material is further improved.

Further, the superfine filling component is nano active calcium carbonate, wherein the maximum grain size is less than 0.1 μm.

Further, the activating agent is phosphogypsum, and the phosphogypsum is washed by water, calcined at 500 ℃ for 30min and then ground into powder with the specific surface area larger than 300m²In terms of/kg. Calcined phosphogypsum not only canThe compound can eliminate the retarding effect and can be used as a sulfate excitant to improve the reaction activity of the superfine composite admixture.

Further, the water-retaining agent is sodium polyacrylate.

The preparation method of the superfine composite admixture for concrete comprises the following steps:

s1, mixing the phosphorus slag, the slaked lime powder and the aluminum sulfate, dripping isooctanol into the mixture, and grinding the mixture until the specific surface area is not less than 300m²And/kg, then transferring the mixture into an air flow mill until the specific surface area is 600-650 m²Homogenizing and standing for 1d to obtain superfine modified phosphorus slag powder;

s2, washing the activator with water, calcining at 500 ℃ for 30min, and grinding to a specific surface area of more than 300m²/kg, then mixing with a water-retaining agent to obtain a mixture of the water-retaining agent and an activating agent;

s3, uniformly mixing the superfine modified phosphorous slag powder, the modified pozzolanic material, the superfine filling component, the water-retaining agent and the activator according to the mass ratio to obtain the superfine composite admixture.

Further, the preparation method of the modified pozzolanic material comprises the following steps: grinding the pozzolanic material to a specific surface area of not less than 300m²/kg, then transferring into a jet mill until the specific surface area is not less than 1000m²And/kg, adding a titanate coupling agent accounting for 0.5 percent of the total mass of the pozzolanic material for surface modification to obtain the modified pozzolanic material.

By adopting the technical scheme, the grain size distribution of the obtained superfine powder is concentrated by adopting a small grinding mill and then adopting an air flow mill after test, and the grain size of most of the powder is in the range of 0.5-15 mu m, which is a grain size area with the largest contribution to the activity of the admixture; grinding the superfine modified phosphorus slag powder to 600-650 m of specific surface area²/kg (D97 ═ 14.26 μm), modified pozzolanic material milled to specific surface area of not less than 1000m²Per kg (D97 ═ 8.13 μm), with an ultrafine filler component of nano activated carbonic acid (maximum particle size)<0.1 mu m) is mixed according to a specific proportion, and after the mixture is mixed into concrete, the mixture can be matched with cement particles to achieve 'full gradation' in a powder micron interval, so that the most probable pore diameter and the accumulated porosity of a cement-based material are as small as possible, and further, better quality is obtainedSlurry pore structure and higher compactness of concrete. Namely, the superfine composite admixture for concrete with better mechanical property can be obtained by reasonably matching the superfine powder with different grain diameters.

Compared with the prior art, the invention has the following advantages:

1. when the slaked lime powder, the aluminum sulfate and the phosphorus slag in the modifier are ground together, P in the surface layer of the superfine phosphorus slag powder can be ground₂O₅Solidifying to generate calcium phosphate, aluminium phosphate, etc., and the isooctanol is permeated into the micropores of the powder during the process of grinding together and is mixed with the uncured P in the powder under the high-temperature environment of grinding₂O₅The esterification is generated by the reaction, and the phosphorus fixation efficiency of the modifier is further improved. Therefore, the soluble P in the phosphorus slag can be effectively solidified through the synergistic effect of the slaked lime powder, the aluminum sulfate and the isooctanol, so that the soluble P in the phosphorus slag is reduced to be less than 0.5 percent, the delayed coagulation property of the phosphorus slag is eliminated, and the early reaction activity of the phosphorus slag is greatly improved.

2. The modified phosphorus slag powder, the pozzolanic material and the superfine filling component are reasonably matched in particle size, the particle size of most of the modified phosphorus slag powder and the pozzolanic material is in a range of 0.5-15 mu m, the range below 0.1 mu m is supplemented by the doping of the superfine filling component, namely nano calcium carbonate, the raw materials can be matched with cement particles to achieve 'full-graded distribution' in a powder micron range, so that the most possible pore diameter and the accumulated porosity of the cement-based material are as small as possible, further, the concrete with a better slurry pore structure and higher compactness is obtained, and the strength of the concrete is high.

3. The superfine composite admixture obtained by the invention takes industrial solid waste as a main body, is compounded by a plurality of functional materials, has better performance, is suitable for popularization and application, can improve the utilization amount and the utilization rate of the solid waste with lower utilization rate originally, can promote the further development of the admixture technology, reduces the production cost of the admixture, and has great economic benefit.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.