阅读说明：本技术 无碱液体速凝剂及其制备方法 (Alkali-free liquid accelerator and preparation method thereof ) 是由 付光跃 郭松 盛东林 周来 谭志强 于 2020-05-15 设计创作，主要内容包括：本发明公开了一种无碱液体速凝剂及其制备方法,按重量份计包括如下组分：聚合硫酸铝30-50份、硫酸亚铁5-10份、草酸0.1-2份、三异丙醇胺1-5份、氟化钠1-4份、聚丙烯酰胺0.1-2份及试剂载体,以期望解决常见的液体速凝剂的碱性较强、成本较高,不易于保存的问题。(The invention discloses an alkali-free liquid accelerator and a preparation method thereof, wherein the alkali-free liquid accelerator comprises the following components in parts by weight: 30-50 parts of polyaluminium sulfate, 5-10 parts of ferrous sulfate, 0.1-2 parts of oxalic acid, 1-5 parts of triisopropanolamine, 1-4 parts of sodium fluoride, 0.1-2 parts of polyacrylamide and a reagent carrier, so as to solve the problems of strong alkalinity, high cost and difficult storage of common liquid accelerators.)

1. The alkali-free liquid accelerator is characterized by comprising the following components in parts by weight: 30-50 parts of polyaluminium sulfate, 5-10 parts of ferrous sulfate, 0.1-2 parts of oxalic acid, 1-5 parts of triisopropanolamine, 1-4 parts of sodium fluoride, 0.1-2 parts of polyacrylamide and a reagent carrier.

2. The alkali-free liquid accelerator according to claim 1, wherein: the coating comprises the following components in parts by weight: 35-50 parts of polyaluminium sulfate, 6-10 parts of ferrous sulfate, 0.5-2 parts of oxalic acid, 2-5 parts of triisopropanolamine, 2-4 parts of sodium fluoride, 0.5-2 parts of polyacrylamide and a reagent carrier.

3. The alkali-free liquid accelerator according to claim 1, wherein: the coating comprises the following components in parts by weight: 35-40 parts of polyaluminium sulfate, 6-7 parts of ferrous sulfate, 0.5-1 part of oxalic acid, 2-3 parts of triisopropanolamine, 2-3 parts of sodium fluoride, 0.5-1 part of polyacrylamide and a reagent carrier.

4. The alkali-free liquid accelerator according to claims 1 to 3, characterized in that: the reagent carrier is water.

5. A method for producing an alkali-free liquid accelerator according to any one of claims 1 to 4, comprising the steps of:

step A, weighing polyaluminium sulfate, ferrous sulfate, oxalic acid, triisopropanolamine, sodium fluoride, polyacrylamide and deionized water according to a proportion for later use;

b, dissolving polyaluminium sulfate, adding the polyaluminium sulfate and deionized water into a container, heating in a water bath until the polyaluminium sulfate and the deionized water are completely dissolved, and adding oxalic acid into the container to stir to obtain a solution I;

d, dissolving ferrous sulfate, supplementing deionized water into the solution I, adding ferrous sulfate, and heating in a water bath until the ferrous sulfate is dissolved to obtain a solution II;

e, dissolving sodium fluoride, namely putting the sodium fluoride into the solution II to carry out water bath heating, and dissolving the sodium fluoride to obtain a solution III;

and step F, complexing, namely adding triisopropanolamine and polyacrylamide into the solution III, uniformly stirring, and cooling the container to room temperature to obtain the finished product of the alkali-free liquid accelerator.

6. The method for producing an alkali-free liquid accelerator according to claim 5, characterized in that: the water bath heating temperature for dissolving the polyaluminium sulfate is 50-80 ℃, the stirring speed of the water bath heating is 200-300 r/min, the stirring time after the oxalic acid is added is 30-60 minutes, and the concentration of the obtained polyaluminium sulfate is 50%.

7. The method for producing an alkali-free liquid accelerator according to claim 5, characterized in that: the heating temperature of the water bath for dissolving the ferrous sulfate is 60-80 ℃, and the stirring speed is 200-300 r/min.

8. The method for producing a liquid admixture according to claim 5, wherein: the water bath heating temperature for dissolving the sodium fluoride is 60-80 ℃, and the stirring speed is 200-300 r/min.

Technical Field

The invention relates to a concrete spraying process, in particular to an alkali-free liquid accelerator and a preparation method thereof.

Background

The sprayed concrete is generally formed by using a construction method of spraying and pouring fine stone concrete by using a pressure spray gun, and filling prepared cement, sand, stones, water and a certain amount of additives into a spraying machine, conveying the mixture to a spray head and an accelerating agent by using high-pressure air, mixing, and spraying the mixture to the surface of rock or concrete at a high speed.

The sprayed concrete can generate larger dust which has larger harm to human bodies, the mixing uniformity is poorer in the spraying process, the quality of the sprayed concrete is seriously influenced, and meanwhile, the traditional sprayed concrete has larger rebound quantity, so that huge material waste is easily caused and certain influence is caused on the engineering quality and the natural environment; the dry spray process is gradually replaced by the wet spray process.

The wet spraying process mainly adopts a liquid accelerator, the common liquid accelerator has strong alkalinity, is easy to generate alkali aggregate reaction, influences the durability of concrete, has large strength loss in the long-term use process, and is generally used with caution in projects with higher durability requirements; although some liquid accelerators in the market are non-alkaline, the production cost is high, and the liquid accelerators are easy to crystallize and precipitate after being stored for a long time; therefore, it is worth studying how to make the liquid accelerator alkaline, stable in properties, and maintain low production cost.

Disclosure of Invention

The invention aims to provide an alkali-free liquid accelerator and a preparation method thereof, aiming at solving the problems of strong alkalinity, high cost and difficult storage of common liquid accelerators.

In order to solve the technical problems, the invention adopts the following technical scheme:

an alkali-free liquid accelerator comprises the following components in parts by weight: 30-50 parts of polyaluminium sulfate, 5-10 parts of ferrous sulfate, 0.1-2 parts of oxalic acid, 1-5 parts of triisopropanolamine, 1-4 parts of sodium fluoride, 0.1-2 parts of polyacrylamide and a reagent carrier.

The further technical scheme is that the coating comprises the following components in parts by weight: 35-50 parts of polyaluminium sulfate, 6-10 parts of ferrous sulfate, 0.5-2 parts of oxalic acid, 2-5 parts of triisopropanolamine, 2-4 parts of sodium fluoride, 0.5-2 parts of polyacrylamide and a reagent carrier.

The further technical scheme is that the coating comprises the following components in parts by weight: 35-40 parts of polyaluminium sulfate, 6-7 parts of ferrous sulfate, 0.5-1 part of oxalic acid, 2-3 parts of triisopropanolamine, 2-3 parts of sodium fluoride, 0.5-1 part of polyacrylamide and a reagent carrier.

The further technical proposal is that the reagent carrier is water.

The invention also provides a preparation method of the alkali-free liquid accelerator, and the preparation method of the alkali-free liquid accelerator comprises the following steps: weighing polyaluminium sulfate, ferrous sulfate, oxalic acid, triisopropanolamine, sodium fluoride, polyacrylamide and deionized water according to the proportion for later use.

Dissolving polyaluminium sulfate, adding the polyaluminium sulfate and deionized water into a container, heating in a water bath until the polyaluminium sulfate and the deionized water are completely dissolved, and adding oxalic acid into the container to stir to obtain a solution I.

Dissolving ferrous sulfate, supplementing deionized water into the solution I, and adding ferrous sulfate to carry out water bath heating until the ferrous sulfate is dissolved, thereby obtaining a solution II.

And (3) dissolving sodium fluoride, putting the sodium fluoride into the solution II for water bath heating, and dissolving the sodium fluoride to obtain a solution III.

And (3) complexing, namely adding triisopropanolamine and polyacrylamide into the solution III, uniformly stirring, and cooling the container to room temperature to obtain the finished product of the alkali-free liquid accelerator.

Preferably, the water bath heating temperature for dissolving the polyaluminium sulfate is 50-80 ℃, the stirring speed for water bath heating is 200-300 r/min, the stirring time after oxalic acid is added is 30-60 minutes, and the concentration of the obtained polyaluminium sulfate is 50%.

Preferably, the heating temperature of the water bath for dissolving the ferrous sulfate is 60-80 ℃, and the stirring speed is 200-300 r/min.

Preferably, the heating temperature of the water bath for dissolving the sodium fluoride is 60-80 ℃, and the stirring speed is 200-300 r/min.

Compared with the prior art, the invention has the beneficial effects of at least one of the following:

the invention takes polyaluminium sulfate as the main component of accelerating coagulation; besides the coagulation promoting effect, the ferrous sulfate and the sodium fluoride can also improve the early strength of the concrete; the oxalic acid is used for adjusting the pH value of the system and is also a complexing agent of aluminum ions, so that the stability of the solution system is improved; triisopropanolamine ensures the later strength of the concrete; the polyacrylamide increases the consistency of the accelerator liquid, further improves the stability of the alkali-free liquid accelerator, and simultaneously can reduce the rebound quantity of sprayed concrete, so that the alkali-free liquid accelerator formed by the formula has the advantages of low cost, no alkali, good stability and easy storage.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.