Biogas waste liquid cement grinding aid and preparation method thereof

Abstract

The application discloses a biogas waste liquid cement grinding aid and a preparation method thereof, and belongs to the technical field of cement grinding aids.The biogas waste liquid cement grinding aid comprises 100 parts of biogas waste liquid and 1-2 parts of sodium formate in terms of mass fraction.The preparation method comprises the following steps: adding sodium formate into the biogas waste liquid, and stirring to perform an activation reaction to obtain the biogas waste liquid cement grinding aid.The grinding aid realizes resource utilization of the biogas waste liquid, is energy-saving and environment-friendly, has the characteristics of non-toxicity, non-corrosion and non-side effect, and has no adverse effect on the durability of concrete.

Description

Technical Field

[0001] This invention belongs to the field of cement grinding aid technology, and particularly relates to a biogas waste liquid cement grinding aid and its preparation method. Background Technology

[0002] Cement grinding aids, as key chemical additives in the modern cement industry, are undergoing unprecedented technological innovation and scientific exploration. With the increasing global demands for green building and sustainable development, cement grinding aid technology has evolved from simply improving grinding efficiency to a comprehensive technological field integrating energy conservation, performance enhancement, and environmental emission reduction. Driving technological innovation and product upgrades in this field has become an important direction for the industry.

[0003] In the prior art, Chinese patent CN106587697A discloses a method for preparing a composite cement grinding aid based on biogas slurry. The biogas slurry used in this method is itself a bio-organic fertilizer with both fast and long-lasting effects, capable of completely replacing chemical fertilizers and serving as a high-quality waste material for organic food production. Biogas slurry is rich in nutrients such as nitrogen, phosphorus, and potassium, and also contains various amino acids, vitamins, proteins, gibberellins, auxins, sugars, nucleic acids, antibiotics, and active resistant substances such as butyric acid, indoleacetic acid, and vitamin B12, thus possessing the dual function of promoting crop growth and inhibiting disease occurrence. However, this patent requires the use of silica-supported nano-adsorption catalysts to remove heavy metals and other harmful components from the biogas slurry, resulting in a complex process and additional processing costs, thus limiting its convenience and economic viability for industrial application. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a biogas waste liquid cement grinding aid and its preparation method. The aim is to overcome the technical deficiency of existing cement grinding aids that cannot be directly produced using biogas waste liquid, while simultaneously improving the product stability, cement grinding efficiency, and cement strengthening effect of the biogas waste liquid cement grinding aid. This technology combines energy conservation, environmental protection, green emission reduction, and waste utilization, and is simple to process and convenient to produce, possessing significant market competitiveness and important promotional value for cement production and practical applications.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A biogas waste liquid cement grinding aid, by mass parts, comprises: 100 parts biogas waste liquid and 1-2 parts sodium formate.

[0007] The biogas waste liquid cement grinding aid provided by this invention is a functional material that improves cement grinding efficiency, reduces energy consumption, optimizes performance, and enhances strength through the synergistic effect of physical and chemical processes. Its core chemical action lies in adsorption and energy reduction, as well as grinding enhancement: as a surface-active substance, the grinding aid molecule possesses both hydrophilic groups (such as -OH, -COOH, -SO3H) and hydrophobic groups, enabling it to quickly adsorb onto the fresh surface, fracture surface, and cracks of cement particles. On the one hand, it neutralizes particle charge, significantly reduces surface energy, and weakens electrostatic attraction between particles, thereby preventing fine particles from adhering and agglomerating. Simultaneously, it reduces particle adhesion on grinding media and separators, effectively preventing clogging and ensuring continuous high efficiency in the grinding process. On the other hand, the molecules can penetrate into particle cracks through a splitting effect, forming splitting stress at the crack tip, promoting crack propagation, and making cement particles easier to break. At the physical level, its core mechanism focuses on regulating particle dispersibility: the grinding aid ions in biogas waste liquid alter the surface electrical properties of cement particles, promoting dispersion and electrostatic repulsion. These ionic grinding aid molecules react with sodium formate and adsorb onto the particle surface, ensuring all particles carry the same negative charge. This electrostatic repulsion maintains dispersion and inhibits agglomeration. Simultaneously, the polymer molecular layers formed by long molecular chains on the particle surface overlap and compress, generating physical repulsion and further consolidating the dispersion effect through steric hindrance. During the cement hydration stage, this grinding aid further promotes uniform dispersion of cement particles, accelerates cement mineral dissolution, and drives the formation of more dense CSH gel from hydration products. It also disrupts the inert protective layer on the surface of clinker admixtures, fully stimulating their potential activity and allowing them to participate more deeply in the secondary hydration reaction. Through the synergistic effect of these physical and chemical processes, it not only significantly promotes cement strength development and improves grinding efficiency but also enables the resource utilization of biogas waste liquid, achieving the dual benefits of energy conservation and environmental protection.

[0008] Furthermore, the biogas waste liquid is the liquid remaining after the livestock waste residue has undergone anaerobic fermentation to produce biogas.

[0009] Furthermore, the liquid contains sodium and has a pH value of 6-8.

[0010] The present invention also provides a method for preparing a biogas waste liquid cement grinding aid, comprising the following steps: adding sodium formate to biogas waste liquid, stirring to carry out an activation reaction, and obtaining a biogas waste liquid cement grinding aid.

[0011] Furthermore, the activation reaction takes 3 minutes.

[0012] The activation time is limited in this invention because a time less than 3 minutes will result in incomplete reaction of the raw materials.

[0013] Furthermore, the activation reaction is carried out at a temperature of -3 to 39°C.

[0014] This invention also provides an application of biogas waste liquid cement grinding aid in cement production.

[0015] Furthermore, the dosage of the biogas waste liquid cement grinding aid is 0.1% of the mass of the grinding material.

[0016] Furthermore, the grinding material is a mixture of cement clinker and gypsum.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] The biogas waste liquid-based cement grinding aid provided by this invention has excellent comprehensive performance, with the following core advantages: it can increase the grinding efficiency of cement production by 20-24%, while reducing the power consumption per ton of cement by 4.5-5.0 kWh, significantly improving grinding efficiency and energy saving; in terms of mechanical properties, it can effectively enhance cement strength, increasing the 3-day compressive strength by 4.5-6.5 MPa and the 28-day compressive strength by 6.4-8.6 MPa; in terms of raw material compatibility, it can increase the amount of admixtures, achieving a 10-15% reduction in clinker usage and lowering production costs; in terms of physical properties, it can improve the physical properties of cement such as fluidity and reduce cement caking; in terms of environmental protection and safety, this grinding aid realizes the resource utilization of biogas waste liquid, which is both energy-saving and environmentally friendly, and has the characteristics of being non-toxic, non-corrosive, and without side effects, and has no adverse effects on the durability of concrete, fully complying with the requirements of GB / T26748-2011 cement grinding aid standard. Detailed Implementation

[0019] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0022] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0023] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0024] This invention provides a method for preparing and applying a biogas waste liquid cement grinding aid, comprising the following steps:

[0025] I. Preparation of Experimental Materials

[0026] 1. Accurately weigh the raw materials according to the following mass proportions: 100 parts of biogas waste liquid and 1-2 parts of sodium formate (for example, 1 part, 1.5 parts or 2 parts of sodium formate).

[0027] 2. Confirmation of raw material specifications: The waste liquid discharged from a large poultry farm in Xuyi is used as the raw material for biogas waste liquid of this invention after being activated into biogas in a digester. The waste liquid contains trace element sodium and has a pH value of 6-8; industrial grade commercially available sodium formate is selected.

[0028] II. Preparation of Cement Grinding Aid for Biogas Waste Liquid

[0029] 1. Add 100 portions of the weighed biogas waste liquid to the mixing tank, adjust the ambient temperature to -3 to 39℃ (indoor natural conditions are sufficient), and start the mixing equipment for pre-mixing.

[0030] 2. Slowly add 1-2 parts of sodium formate to the stirred biogas waste liquid, keep stirring to carry out the activation reaction, continue stirring for 3 minutes to ensure that the raw materials are fully mixed and activated, and obtain the finished biogas waste liquid cement grinding aid.

[0031] III. Application of biogas waste liquid as a cement grinding aid

[0032] 1. Application: Cement grinding aid.

[0033] 2. Addition of grinding aid: Accurately measure 0.1% of the prepared biogas waste liquid cement grinding aid by mass of the grinding material, and add it to the grinding system together with the grinding material. The grinding material is cement clinker and a mixture, in which the mass ratio of cement clinker is 65-75% (e.g., 65%, 70% or 75%).

[0034] 3. Grinding and Testing: Start the grinding equipment for normal grinding operations. After grinding, test the fineness, specific surface area, setting time, fluidity, compressive strength and other performance indicators of the cement in accordance with the national standards GB / T26748 "Cement Grinding Aids" and GB / T17671 "Test Method for Strength of Cement Mortar".

[0035] Unless otherwise specified, the term "parts" in this invention refers to parts by weight.

[0036] All raw materials used in this invention were purchased from the market.

[0037] The technical solution of the present invention will be further illustrated by the following embodiments.

[0038] Example 1

[0039] A method for preparing a cement grinding aid from biogas waste liquid, comprising the following steps:

[0040] Under natural indoor conditions, 100 parts of biogas waste liquid were poured into a mixing tank and stirred. One part of sodium formate was added, and stirring was continued for 3 minutes to obtain biogas waste liquid cement grinding aid.

[0041] Example 2

[0042] A method for preparing a cement grinding aid from biogas waste liquid, comprising the following steps:

[0043] At room temperature, 100 parts of biogas waste liquid were poured into a mixing tank and stirred. 1.5 parts of sodium formate were added and stirred for another 3 minutes to obtain biogas waste liquid cement grinding aid.

[0044] Example 3

[0045] A method for preparing a cement grinding aid from biogas waste liquid, comprising the following steps:

[0046] At room temperature, 100 parts of biogas waste liquid were poured into a mixing tank and stirred. 2 parts of sodium formate were added, and stirring was continued for 3 minutes to obtain biogas waste liquid cement grinding aid.

[0047] Comparative Example 1

[0048] Examples 1-3 compare the products with the blank. According to the national standards GB / T26748 "Cement Grinding Aids" and GB / T17671 "Test Method for Strength of Cement Mortar", the fineness, specific surface area, setting time, fluidity and compressive strength of cement were tested. The results are shown in Table 1 (Table 0 indicates no grinding aid was added, which serves as the control group).

[0049] Table 1 Performance test results of Examples 1-3 and the control group

[0050]

[0051] The following conclusions can be drawn from Table 1:

[0052] 1) Grinding Efficiency: During the application of Examples 1-3, the hourly outputs were 295t / h, 310t / h, 255t / h, 295t / h, 310t / h, 255t / h, 295t / h, 310t / h, and 255t / h, respectively. Compared with the state before using biogas waste cement grinding aid, the hourly output increased by 50t / h, 60t / h, and 50t / h, respectively, while the 45μm sieve residue decreased by 2.0%, 2.2%, 2.4%, 2.1%, 2.1%, 2.3%, 2.2%, 2.5%, and 2.1%. The grinding efficiency increased by 20%, 24%, and 21%, respectively. Power consumption decreased by 4.5kWh, 5.0kWh, and 4.5kWh, respectively. This represents a 20-30% increase in grinding efficiency and a 4.5-10kWh reduction in power consumption.

[0053] 2) Strength Performance: In production applications, under the condition of unchanged clinker ratio, the 3-day compressive strength of cement in Examples 1-3 increased from 29.3 MPa to 35.5 MPa (an increase of 6.2 MPa), 27.5 MPa to 32.8 MPa (an increase of 5.3 MPa), and 25.6 MPa to 30.9 MPa (an increase of 5.3 MPa); 29.1 MPa to 35.6 MPa (an increase of 6.5 MPa), 27.2 MPa to 33.6 MPa (an increase of 6.4 MPa), and 25.1 MPa to 30.5 MPa (an increase of 5.4 MPa); 29.1 MPa to 35.6 MPa (an increase of 6.5 MPa), 27.1 MPa to 33.4 MPa (an increase of 6.3 MPa), and 25.1 MPa to 30.9 MPa (an increase of 5.3 MPa), respectively. The 28-day compressive strength increased from 52.5 MPa to 59.6 MPa (an increase of 7.1 MPa), 51.5 MPa to 58.6 MPa (an increase of 7.1 MPa), 50.1 MPa to 56.5 MPa (an increase of 6.4 MPa), 52.6 MPa to 59.9 MPa (an increase of 7.3 MPa), 51.9 MPa to 60.5 MPa (an increase of 8.6 MPa), 50.5 MPa to 58.1 MPa (an increase of 7.6 MPa), 52.6 MPa to 60.5 MPa (an increase of 7.9 MPa), 51.0 MPa to 59.5 MPa (an increase of 8.5 MPa), and 50.6 MPa to 57.1 MPa (an increase of 6.5 MPa).

[0054] 3) Energy saving and clinker reduction: In production applications, Examples 1-3 show that the original clinker ratio is 75%, and the clinker usage is reduced by 10%. If P.C42.5 cement is produced, the 3-day and 28-day strengths are increased by 6.0 MPa and 8.0 MPa respectively compared to before the addition of biogas waste liquid cement grinding aid. This achieves the goal of replacing 10-15% of the clinker.

[0055] 4) Stability and Adaptability: The biogas waste liquid cement grinding aids in Examples 1-3, when applied to cement production, produce cement with stable quality performance, minimal fluctuations, small errors, and no clogging phenomenon. It is adaptable to different varieties and batches of clinker and blended materials. Therefore, the grinding aid of this invention can achieve a 20-24% increase in grinding efficiency, a 4.5-6.5 MPa increase in 3-day compressive strength, a 6.4-8.6 MPa increase in 28-day compressive strength, a 10-15% reduction in clinker usage, a 4.5-5.0 kWh reduction in power consumption, and improved cement fluidity and other properties, resulting in significant overall benefits.

[0056] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cement grinding aid made from biogas waste liquid, characterized in that, The raw materials, by mass, include: 100 parts of biogas waste liquid and 1-2 parts of sodium formate; the biogas waste liquid cement grinding aid is prepared by stirring and activating biogas waste liquid and sodium formate at -3 to 39°C for 3 minutes.

2. The biogas waste liquid cement grinding aid according to claim 1, characterized in that, The biogas waste liquid is the liquid remaining after the aquaculture waste residue is anaerobically fermented to produce biogas.

3. The biogas waste liquid cement grinding aid according to claim 2, characterized in that, The liquid contains sodium and has a pH of 6-8.

4. A method for preparing a biogas waste liquid cement grinding aid as described in any one of claims 1-3, characterized in that, Includes the following steps: Sodium formate is added to biogas waste liquid and stirred to carry out an activation reaction, thereby obtaining biogas waste liquid cement grinding aid; the activation reaction time is 3 minutes; the activation reaction temperature is -3 to 39℃.

5. The application of the biogas waste liquid cement grinding aid as described in any one of claims 1-3 in cement production.

6. The application according to claim 5, characterized in that, The dosage of the biogas waste liquid cement grinding aid is 0.1% of the mass of the grinding material.

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