Preparation method of environment-friendly shield tunneling machine special foaming agent based on agricultural byproduct extract

Abstract

The invention relates to the technical field of preparation of an environment-friendly foaming agent for a large shield tunneling machine, and particularly discloses a preparation method of an environment-friendly foaming agent special for a shield tunneling machine based on an agricultural byproduct extract. And keeping the reaction system in a boiling state for a plurality of time, taking supernate as foaming agent mother liquor through a solid-liquid separation device, and compounding and blending the foaming agent mother liquor with a foam stabilizer and a fluidity improver. The invention provides a modified foaming agent which is more suitable for shield soil residues of a shield tunneling machine, and has the main innovation points that a special environment-friendly foaming agent (the degradable rate is greater than 95%) for shield tunneling is invented, the flow dynamic state of the shield soil residues is greatly optimized (the fluidity is improved by 31.2%), and the foaming stability of the foaming agent is further enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of large-scale shield machine foaming agent preparation, and in particular to an environmentally friendly disposal method and application of agricultural by-products. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] The comprehensive performance indicators of domestic shield foaming agents are comparable to those of imported products, and some indicators even exceed those of imported products. Moreover, the price is only 30% to 60% of that of imported products, which has been recognized by construction units. However, the main raw materials of shield foaming agent products commonly used on the market are all derived from petroleum derivatives, which are fossil energy materials and cannot be degraded. They affect the normal growth of vegetation in shield slag and cause "secondary pollution" to the environment. Therefore, in recent years, the slag produced during shield construction has gradually become a new type of solid by-product, which has attracted the attention of national environmental protection departments. With the national ecological civilization construction and the "dual carbon" policy, government departments have put forward the requirement that "shield foaming agents should not harm the surrounding environment." However, most of the plant protein foaming agents currently sold on the market are foaming agents for foamed concrete, and various properties rely on the performance research and development of foamed concrete, which is difficult to meet the performance requirements of shield soil foaming agents. The present invention fills the gap in the field of environmentally friendly and degradable foaming agents for large shield machines in China. Summary of the invention

[0004] The present invention provides a method and application for preparing an environmentally friendly and degradable large shield machine foaming agent using bulk agricultural by-products. The method prepares bulk agricultural by-products into an environmentally friendly large shield machine foaming agent with excellent stability and a degradability rate of more than 95% (100% harmlessness of degradation products). The product involved in the invention can not only solve the problem of agricultural by-product disposal, but also has environmental protection and degradability, avoiding the pollution of shield soil residue caused by the use of non-degradable fossil material foaming agents. In addition, the present invention provides a method for using admixtures to compound and specifically improve the compatibility of traditional plant protein foaming agents in shield soil residue foams. To achieve the above purpose, the present invention uses the technical scheme described below.

[0005] First, the present invention discloses a method for preparing a large shield machine foaming agent using bulk agricultural byproducts, comprising the following steps: (1) The bulk agricultural by-product containing plant protein is placed in a blast drying oven for drying, crushed by a crushing device and then sieved; then the crushed powder is mixed with a reaction enzyme and water and stirred for reaction under heating conditions, and the reaction product is freeze-dried to obtain a protein extract containing modified agricultural by-products; the reaction enzyme is a composite reaction enzyme; (2) grinding the freeze-dried protein extract, adding an alkaline surfactant, performing ultrasonic dispersion treatment, and then placing it in a heating device for heating to accelerate protein dissolution; after the reaction is completed, the extract is allowed to stand, and the supernatant is taken out as a mother liquor through a solid-liquid separation device for standby use; (3) The prepared foaming agent mother liquid, foam stabilizer, and shield soil fluidity improver are mixed and stirred evenly using a stirrer to achieve the best performance requirements for the foaming agent that is more suitable for shield machines, and finally an environmentally friendly and degradable large shield machine foaming agent is prepared using bulk agricultural by-products. In this step, the fluidity improver has the functions of improving the fluidity of the shield soil and maintaining the stability of the foam.

[0006] Furthermore, in step (1), the ratio of the agricultural by-product, the reaction enzyme, and water is 10-30 parts by weight; 0.0002-0.0003 parts by weight; and 50-100 parts by weight.

[0007] Furthermore, in step (1), the solid by-product includes but is not limited to at least one of agricultural by-products such as straw, rice husk, melon seed shell, soybean meal, etc. The main components of these solid by-products are plant fiber, tea saponin, and plant protein, and the effective component is plant protein. After the alkaline surface modifier and the reaction enzyme are used to extract the protein and modify it, the material can be dissolved in water and the surface is modified, which is convenient for further modification.

[0008] Furthermore, in step (1), the ratio of the reaction enzyme is 0.0002-0.0003 parts by weight, and the reaction enzyme is a composite reaction enzyme with a composite ratio of pectinase:cellulase of 2:3.

[0009] Furthermore, in step (1), the drying temperature ranges from 65 to 90° C., and the reaction time is from 10 to 14 hours.

[0010] Furthermore, in step (1), the sieving mesh size is 100-150 meshes.

[0011] Furthermore, in step (1), the heating and stirring temperature range is 60-85° C., the stirring rate is 650-900 rpm, and the stirring time is 40-60 min.

[0012] Furthermore, in step (1), the freeze-drying temperature of the freeze-drying treatment is -20 to -40°C, and the freeze-drying time is 12 to 24 hours.

[0013] Furthermore, in step (2), the proportion of the alkaline surfactant is 3 to 5 parts by weight: Optionally, the alkaline substance includes at least one of ammonium stearate, tritetradecylmethyltri(2-hydroxyethyl)ammonium oxide, dodecyldimethylbenzyl ammonium chloride, etc.

[0014] Furthermore, in step (2), the ultrasonic dispersion time is 10-30 min, and the ultrasonic power is 200-400 kHz.

[0015] Furthermore, in step (2), the heating temperature is 60-100° C., and the heating time is 2-6 hours.

[0016] Furthermore, in step (2), the ratio of the protein extract, the alkaline surface modifier and water is 5-15 parts by weight, 3-5 parts by weight, or 50-100 parts by weight.

[0017] Furthermore, in step (2), the solid-liquid separation device is one of a cyclone screening machine, a vacuum filter, and a compression filter.

[0018] Furthermore, in step (3), the ratio of the foam stabilizer is 0.2-0.5: Optionally, the foam stabilizer includes at least one of gelatin, gum arabic, hydroxypropyl methylcellulose ether, etc. In the present invention, the main function of the stabilizer is to stabilize the volume stability of the foaming agent during the foaming process.

[0019] Furthermore, in step (3), the ratio of the fluidity improver of the shield soil is 0.2-0.5: Optionally, the fluidity improver includes at least one of naphthalenesulfonate formaldehyde condensate, wood calcium, methyl allyl polyoxyethylene ether, polyoxyethylene ether, etc. In the present invention, the function of the fluidity improver is to improve the fluidity of the slag after mixing with the shield soil slag.

[0020] Compared with the prior art, the present invention has at least the following beneficial technical effects: This technology provides a more efficient and environmentally friendly foaming agent option for large shield machine shield soil residue foaming agents. For traditional plant protein foaming agents, their foam stability is often based on the reduction of foam fluidity. The essential reason is that the foam stability is directly related to the fluidity of the water film in the foam gap. This often leads to a contradiction between foam stability and shield soil residue fluidity, making it difficult to achieve rapid transfer of shield soil residue in a stable state, which greatly reduces the shield advancement rate of the shield machine. On the basis of traditional plant protein foaming agents, the present invention provides a modification scheme that is more suitable for use in shield soil residue of shield machines, among which the main innovations are: a single environmentally friendly foaming agent achieves a significant optimization of the flow state of shield soil residue, and the foaming stability of the foaming agent is further enhanced. Its main principle is to extract the mother liquor of foaming components through physical and chemical treatment of agricultural by-products. In the composite preparation process, a fluidity improver that is compatible with the mother liquor of the foaming agent or can improve the foaming performance is used to significantly improve the stability and fluidity of the foam. The fluidity improver of the present invention has the function of improving the stability of the foam. At the same time, after foaming and mixing with the shield soil, it can be quickly adsorbed on the surface of the shield soil slag particles to form an interface film structure, effectively reducing the friction between the shield soil slag particles and improving its fluidity. Finally, the present invention realizes the efficient application of a single environmentally friendly and degradable foaming agent in shield operations, which not only improves the fluidity of the shield soil slag, but also ensures the long-term stability of the foam. This innovative foaming agent solution not only meets the requirements of shield construction, but also takes into account environmental protection, providing a new solution for the sustainable development of underground engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein: Figure 1 and Figure 2 is a test diagram of the foaming agent prepared in the following Example 1; Figure 3 and Figure 4 The following is a test chart of the foaming agent prepared in Example 4. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with specific embodiments. These embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. The preferred implementation methods and materials described herein are only for demonstration purposes. The present invention is described in detail below in conjunction with specific implementation methods. Example 1

[0023] A method for producing an environmentally friendly foaming agent for a shield machine using bulk agricultural byproducts comprises the following steps: 1. Preparation of foaming agent mother solution: (1) Prepare the following raw material components: 10 parts by weight of soybean meal, 3 parts by weight of ammonium stearate, 0.0002 parts by weight of composite reaction enzyme, and 50 parts by weight of water.

[0024] (2) The soybean meal was placed in a forced air drying oven at 85°C and dried for 12 hours, and then crushed using a crushing device and passed through a 100-mesh sieve; the crushed powder was then mixed with a composite reaction enzyme and water, and stirred for reaction at 95°C and 650 rpm for 60 minutes, and the reaction product was freeze-dried at -20°C for 24 hours to obtain a protein extract containing modified agricultural by-products.

[0025] (3) After grinding the freeze-dried protein extract, add ammonium stearate and perform ultrasonic dispersion treatment at 240 kHz for 30 min. Then place it in a heating device and heat it at 85°C for 2 h to accelerate protein dissolution. After the reaction is completed, let it stand and remove the supernatant as the mother liquor through a solid-liquid separation device for later use.

[0026] 2. Foaming agent compounding process: (1) Prepare the following raw material components: 0.5 parts by weight of gelatin and 0.2 parts by weight of naphthalenesulfonate formaldehyde condensate.

[0027] (2) The foaming agent mother solution prepared in this example is compounded with gelatin and naphthalenesulfonate formaldehyde condensate to achieve the best performance requirements of the foaming agent more suitable for shield machine, thus obtaining the foaming agent. Example 2

[0028] A method for producing an environmentally friendly foaming agent for a shield machine using bulk agricultural byproducts comprises the following steps: 1. Preparation of foaming agent mother solution: (1) Prepare the following raw material components: 25 parts by weight of sunflower seed hulls, 5 parts by weight of dodecyldimethylbenzyl ammonium chloride, 0.00028 parts by weight of composite reaction enzyme, and 60 parts by weight of water.

[0029] (2) The sunflower seed shells were placed in a forced air drying oven at 95°C and dried for 10 h. The shells were crushed using a crushing device and then passed through a 150-mesh sieve. The crushed powder was then mixed with a composite reaction enzyme and water and stirred for reaction at 60°C and 800 rpm for 50 min. The reaction product was freeze-dried at -40°C for 12 h to obtain a protein extract containing modified agricultural by-products.

[0030] (3) After grinding the freeze-dried protein extract, add dodecyl dimethyl benzyl ammonium chloride and perform ultrasonic dispersion treatment at 300 kHz for 15 min. Then place it in a heating device and heat it at 65°C for 4 h to accelerate protein dissolution. After the reaction is completed, let it stand and take out the supernatant as the mother liquor through a solid-liquid separation device for later use.

[0031] 2. Foaming agent compounding process: (1) Prepare the following raw material components: 0.3 parts by weight of gum arabic and 0.4 parts by weight of methyl allyl polyoxyethylene ether.

[0032] (2) The foaming agent mother solution prepared in this example is compounded with gum arabic and methyl allyl polyoxyethylene ether to achieve the best performance requirements of the foaming agent more suitable for shield machine, thereby obtaining the foaming agent. Example 3

[0033] A method for producing an environmentally friendly foaming agent for a shield machine using bulk agricultural byproducts comprises the following steps: 1. Preparation of foaming agent mother solution: (1) Prepare the following raw material components: 15 parts by weight of sunflower seed hulls, 4 parts by weight of dodecyldimethylbenzyl ammonium chloride, 0.0003 parts by weight of composite reaction enzyme, and 70 parts by weight of water.

[0034] (2) The sunflower seed shells were placed in a forced air drying oven at 90°C and dried for 12 hours, and then crushed using a crushing device and passed through a 120-mesh sieve; the crushed powder was then mixed with a composite reaction enzyme and water, and stirred for reaction at 80°C and 700 rpm for 45 minutes; the reaction product was freeze-dried at -25°C for 12 hours to obtain a protein extract containing modified agricultural by-products.

[0035] (3) After grinding the freeze-dried protein extract, add ammonium stearate and perform ultrasonic dispersion treatment at 280 kHz for 25 min. Then place it in a heating device and heat it at 75°C for 3 h to accelerate protein dissolution. After the reaction is completed, let it stand and remove the supernatant as the mother liquor through a solid-liquid separation device for later use.

[0036] 2. Foaming agent compounding process: (1) Prepare the following raw material components: 0.2 parts by weight of gelatin and 0.5 parts by weight of polyoxyethylene ether.

[0037] (2) The foaming agent mother solution prepared in this example is compounded with gelatin and polyoxyethylene ether to achieve the best performance requirements of the foaming agent more suitable for shield machines, thereby obtaining a foaming agent. Example 4

[0038] A method for producing an environmentally friendly foaming agent for a shield machine using bulk agricultural byproducts comprises the following steps: 1. Preparation of foaming agent mother solution: (1) Prepare the following raw material components: 10 parts by weight of soybean meal, 3 parts by weight of tritetradecylmethyltri(2-hydroxyethyl)ammonium oxide, 0.0002 parts by weight of composite reaction enzyme, and 50 parts by weight of water.

[0039] (2) The soybean meal was placed in a forced air drying oven at 80°C and dried for 13 hours. The soybean meal was crushed using a crushing device and then passed through a 115-mesh sieve. The crushed powder was then mixed with a composite reaction enzyme and water and stirred for reaction at 70°C and 7500 rpm for 50 minutes. The reaction product was freeze-dried at -35°C for 18 hours to obtain a protein extract containing modified agricultural by-products.

[0040] (3) After grinding the freeze-dried protein extract, add tritetradecylmethyltri(2-hydroxyethyl)ammonium oxide and perform ultrasonic dispersion treatment at 320 kHz for 15 min. Then, place it in a heating device and heat it at 65°C for 5 h to accelerate protein dissolution. After the reaction is completed, let it stand and remove the supernatant as the mother liquor through a solid-liquid separation device for later use.

[0041] 2. Foaming agent compounding process: (1) Prepare the following raw material components: 0.4 parts by weight of gelatin and 0.3 parts by weight of wood calcium.

[0042] (2) The foaming agent mother solution prepared in this example is compounded with gelatin and wood calcium to achieve the best performance requirements of the foaming agent more suitable for shield machine, thus obtaining the foaming agent. Example 5

[0043] A method for producing an environmentally friendly foaming agent for a shield machine using bulk agricultural byproducts comprises the following steps: 1. Preparation of foaming agent mother solution: (1) Prepare the following raw material components: 18 parts by weight of straw, 3 parts by weight of ammonium stearate, 0.00025 parts by weight of composite reaction enzyme, and 100 parts by weight of water.

[0044] (2) The straw was placed in a forced air drying oven at 70°C and dried for 12 h. The straw was crushed using a crushing device and then passed through a 130-mesh sieve. The crushed powder was then mixed with a composite reaction enzyme and water and stirred for reaction at 75°C and 850 rpm for 30 min. The reaction product was freeze-dried at -20°C for 15 h to obtain a protein extract containing modified agricultural by-products.

[0045] (3) After grinding the freeze-dried protein extract, ammonium stearate was added and ultrasonic dispersion was performed at 400 kHz for 12 min. The extract was then placed in a heating device and heated at 60°C for 6 h to accelerate protein dissolution. After the reaction was completed, the extract was allowed to stand and the supernatant was taken out as the mother liquor through a solid-liquid separation device for later use.

[0046] 2. Foaming agent compounding process: (1) Prepare the following raw material components: 0.2 parts by weight of gelatin and 0.5 parts by weight of naphthalenesulfonate formaldehyde condensate.

[0047] (2) The foaming agent mother solution prepared in this example is compounded with gelatin and naphthalenesulfonate formaldehyde condensate to achieve the best performance requirements of the foaming agent more suitable for shield machine, thus obtaining the foaming agent. Example 6

[0048] A method for producing an environmentally friendly foaming agent for a shield machine using bulk agricultural byproducts comprises the following steps: 1. Preparation of foaming agent mother solution: (1) Prepare the following raw material components: 10 parts by weight of rice husk, 3 parts by weight of tritriadecylmethyltri(2-hydroxyethyl)ammonium oxide, 0.0003 parts by weight of composite reaction enzyme, and 80 parts by weight of water.

[0049] (2) The rice husks were placed in a forced air drying oven at 90°C and dried for 10 h. The husks were crushed using a crushing device and passed through a 140-mesh sieve. The crushed powder was then mixed with a composite reaction enzyme and water and stirred for reaction at 85°C and 850 rpm for 55 min. The reaction product was freeze-dried at -40°C for 12 h to obtain a protein extract containing modified agricultural by-products.

[0050] (3) After grinding the freeze-dried protein extract, add tritetradecylmethyltri(2-hydroxyethyl)ammonium oxide and perform ultrasonic dispersion treatment at 340 kHz for 55 min. Then, place it in a heating device and heat it at 80°C for 3 h to accelerate protein dissolution. After the reaction is completed, let it stand and remove the supernatant as the mother liquor through a solid-liquid separation device for later use.

[0051] 2. Foaming agent compounding process: (1) Prepare the following raw material components: 0.5 parts by weight of hydroxypropyl methylcellulose ether and 0.4 parts by weight of calcium carbonate.

[0052] (2) The foaming agent mother liquor prepared in this example is compounded with hydroxypropyl methylcellulose ether and wood calcium to achieve the best performance requirements for the foaming agent suitable for shield machines.

[0053] The properties of the above foaming agents after air compression and foaming are shown in the following table: The test plan is as follows: (1) Foaming ratio The test was carried out in accordance with the requirements of GB / T 7462-94 "Determination of the foaming power of surfactants - Improved Ross-Miles method".

[0054] (2) Volume half-life After using an air compression foaming machine to generate bubbles, the time it takes for the foam to decay from its original volume to half of its original volume is the volume half-life of the foaming agent.

[0055] (3) Drainage half-life After using an air compression foaming machine to generate bubbles, the time it takes for the foam drainage volume to reach half of the original liquid volume is the foam drainage half-life.

[0056] (4) Fluidity of mixed shield soil residue The prepared foaming agent was foamed using a standard foaming machine and mixed with shield slag at a volume ratio of 20% to form foamed mud. The fluidity of the mixed slurry was tested using a standard fluidity measuring cylinder with an inner diameter of 80 mm and a height of 80 mm.

[0057] (5) Degradability The test was carried out in accordance with the requirements of GB / T 15818-2018 “Test method for biodegradability of surfactants”.

[0058] Table 1 Foam performance index of different implementation cases

[0059] From the above test results, it can be seen that the plant protein foaming agent prepared using the present technical solution has high stability and foaming ratio, and the foam fluidity is greatly improved, which can effectively improve the transmission and transfer rate of shield soil slag.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing an environmentally friendly shield machine foaming agent based on agricultural by-product extracts, characterized in that: The steps include: (1) The bulk agricultural by-product containing plant protein is placed in a blast drying oven for drying, crushed by a crushing device and then sieved; then the crushed powder is mixed with a reaction enzyme and water and stirred for reaction under heating conditions, and the reaction product is freeze-dried to obtain a protein extract containing modified agricultural by-products; the reaction enzyme is a composite reaction enzyme; (2) grinding the freeze-dried protein extract, adding an alkaline surfactant, performing ultrasonic dispersion treatment, and then placing it in a heating device for heating to accelerate protein dissolution; after the reaction is completed, the extract is allowed to stand, and the supernatant is taken out as a mother liquor through a solid-liquid separation device for standby use; (3) The prepared foaming agent mother liquor, foam stabilizer and shield soil fluidity improver are mixed and stirred evenly using a stirrer to achieve the best performance requirements for the foaming agent suitable for shield machines, and finally an environmentally friendly and degradable large shield machine foaming agent is prepared using bulk agricultural by-products; the fluidity improver in this step has the functions of improving the fluidity of shield soil and maintaining foam stability.

2. The method for preparing an environmentally friendly shield machine foaming agent based on agricultural by-product extracts according to claim 1, characterized in that: In step (1), the ratio of the agricultural byproduct, the reaction enzyme, and water is 10 to 30 parts by weight; 0.0002 to 0.0003 parts by weight; 50 to 100 parts by weight; Wherein, in step (1), the solid by-product includes but is not limited to at least one of agricultural by-products such as straw, rice husk, melon seed shell, soybean meal, etc.; the main components of these solid by-products are plant fiber, tea saponin, plant protein, and the effective component is plant protein; after the protein is extracted and modified by the alkaline surface modifier and the reaction enzyme, it can be dissolved in water and surface modified, which is convenient for further modification treatment; Wherein, in step (1), the ratio of the reaction enzyme is 0.0002-0.0003 parts by weight, and the reaction enzyme is a composite reaction enzyme with a composite ratio of pectinase:cellulase of 2:

3.

3. The method for preparing an environmentally friendly shield machine foaming agent based on agricultural by-product extracts according to claim 1, characterized in that: In step (1), the drying temperature ranges from 65 to 90°C, and the reaction time is 10 to 14 hours; Wherein, in step (1), the sieving mesh size is 100-150 mesh; Wherein, in step (1), the heating and stirring temperature range is 60-85°C, the stirring rate is 650-900 rpm, and the stirring time is 40-60 min; Wherein, in step (1), the freeze-drying temperature of the freeze-drying treatment is -20 to -40°C, and the freeze-drying time is 12 to 24 hours.

4. The method for preparing an environmentally friendly shield machine-specific foaming agent based on agricultural by-product extracts according to claim 1, characterized in that: In step (2), the ratio of the protein extract, the alkaline surface modifier and water is 5-15 parts by weight, 3-5 parts by weight, and 50-100 parts by weight; Wherein, in step (2), the proportion of the alkaline surfactant is 3 to 5 parts by weight: Optionally, the alkaline substance includes at least one of ammonium stearate, tritetradecylmethyltri(2-hydroxyethyl)ammonium oxide, dodecyldimethylbenzyl ammonium chloride, etc.

5. The method for preparing an environmentally friendly shield machine foaming agent based on agricultural by-product extracts according to claim 1, characterized in that: In step (2), the solid-liquid separation device is one of a cyclone screening machine, a vacuum filter, and a compression filter; Wherein, in step (2), the ultrasonic dispersion time is 10-30 min, and the ultrasonic power is 200-400 kHz; Wherein, in step (2), the heating temperature is 60-100° C. and the heating time is 2-6 hours.

6. The method for preparing an environmentally friendly shield machine foaming agent based on agricultural by-product extracts according to claim 1, characterized in that: In step (3), the stabilizer includes at least one of gelatin, gum arabic, hydroxypropyl methylcellulose ether, etc.; wherein the main function of the stabilizer is to stabilize the volume stability of the foaming agent during the foaming process; Wherein, in step (3), the ratio of the foam stabilizer is 0.2~0.

5.

7. The method for preparing an environmentally friendly shield machine foaming agent based on agricultural by-product extracts according to claim 1, characterized in that: In step (3), the fluidity improver includes at least one of naphthalene sulfonate formaldehyde condensate, wood calcium, methyl allyl polyoxyethylene ether, polyoxyethylene ether, etc.; the function of the fluidity improver is to improve the fluidity of the slag after mixing with the shield soil slag; Wherein, in step (3), the ratio of the shield soil fluidity improver is 0.2~0.

5.

8. Application of the aqueous foam prepared by the method for preparing an environmentally friendly shield machine-specific foaming agent based on agricultural by-product extracts according to any one of claims 1 to 7 in a large shield machine, characterized in that: The foaming agent is generally diluted 30 to 80 times.

Images