A grinding aid for producing cement clinker powder and a method of using the same

Abstract

The application discloses a grinding aid for producing cement clinker powder and a use method thereof. The grinding aid is composed of 20-27 parts by weight of a mixture of hydrogen peroxide and a polyol, 3-6 parts by weight of ethyl orthosilicate, 1.5-2.4 parts by weight of a solid calcium source, 0.5-0.75 parts by weight of a lignin sulfonate and 1-2 parts by weight of modified calcium stearate. The grinding aid is obtained by mixing the above raw materials and then rapidly stirring and dispersing them. The modified calcium stearate is obtained by mixing calcium stearate with an ethanol solution of a polycarboxylic acid water reducing agent and then performing grinding treatment. The use method comprises the following steps: uniformly spraying the grinding aid on cement clinker, standing, and then performing grinding. The grinding aid can not only reduce the energy consumption in the early stage of grinding and improve the grinding efficiency, but also help to improve the early strength of the prepared cement clinker.

Description

Technical Field

[0001] This invention relates to the field of grinding aid preparation technology, specifically to a grinding aid for producing cement clinker powder and its application method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] After firing, cement clinker needs to be ground to a suitable particle size to form a specific particle size distribution, increase the specific surface area, and thus increase the contact area between cement and water, making the hydration reaction of cement more rapid and complete. The grinding of cement clinker not only affects the performance and quality of cement but also directly impacts the mechanical properties and durability of the resulting cement-based materials. However, grinding cement clinker requires significant energy consumption. Adding grinding aids to cement clinker helps improve grinding efficiency, reduce energy consumption, and consequently lower production costs for enterprises.

[0004] Currently, commonly used grinding aids mainly include polyols and polyol amines, which can improve grinding efficiency. This is because during the grinding process, as cement clinker particles gradually become finer, their specific surface area increases. The breakage of bonds on the surface of cement particles leads to electrophoresis and agglomeration, resulting in decreased grinding efficiency and increased energy consumption. However, since cement clinker is obtained through solid-phase reactions of raw materials under high-temperature calcination before grinding, the resulting cement clinker is a relatively hard block. The aforementioned grinding aids generally exert their effects only after the blocky cement clinker has been ground into finer particles, making it difficult to reduce energy consumption and grinding efficiency in the early stages of grinding. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a grinding aid for producing cement clinker powder and its application method. This grinding aid not only reduces energy consumption in the early stages of grinding and improves grinding efficiency, but also helps to enhance the early strength of the prepared cement clinker. Specifically, the technical solution of this invention is as follows.

[0006] First, this invention discloses a grinding aid for producing cement clinker powder, comprising: 20-27 parts by weight of a mixture of hydrogen peroxide and polyol, 3-6 parts by weight of tetraethyl orthosilicate, 1.5-2.4 parts by weight of a solid calcium source, 0.5-0.75 parts by weight of lignin sulfonate, and 1-2 parts by weight of modified calcium stearate. The grinding aid is obtained by rapidly stirring and dispersing the above raw materials evenly.

[0007] Furthermore, the mass fraction of hydrogen peroxide solution in the mixture is 20-30%.

[0008] Furthermore, the polyol includes at least one of ethylene glycol, propylene glycol, and glycerol. The polyol helps reduce the surface energy of cement clinker particles, eliminates electrostatic effects, and accelerates the flowability of cement clinker particles, thereby improving grinding efficiency.

[0009] Further, the solid calcium source includes at least one of calcium oxide, calcium hydroxide, and carbide slag. Optionally, the particle size of the solid calcium source is not less than 400 mesh.

[0010] Furthermore, the lignin sulfonate includes at least one of sodium lignin sulfonate and calcium lignin sulfonate. The lignin sulfonate helps improve the dispersion of cement clinker particles and reduces the friction between cement clinker particles, thereby helping to improve grinding efficiency and reduce energy consumption.

[0011] Furthermore, the modified calcium stearate is obtained by mixing calcium stearate with an ethanol solution of polycarboxylate superplasticizer and then grinding the mixture.

[0012] Furthermore, the ratio of calcium stearate to polycarboxylate superplasticizer in ethanol is 1g:0.4~0.7ml.

[0013] Further, the mass fraction of polycarboxylate superplasticizer in the ethanol solution is 2-3.5%. The mass fraction of the ethanol solution is not less than 80%. Optionally, the particle size of the calcium stearate is not less than 400 mesh.

[0014] Secondly, the method of using the grinding aid for producing cement clinker powder according to the present invention includes the following steps: spraying the grinding aid evenly onto the cement clinker and letting it stand, and then grinding it after completion.

[0015] Furthermore, the grinding aid is added to the cement clinker at a rate of 0.2% to 0.4% of its mass. Optionally, the settling time is 1 to 2 minutes.

[0016] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0017] The cement clinker grinding aid of this invention uses a mixture of hydrogen peroxide and polyol as the mother liquor, and adds functional components such as tetraethyl orthosilicate, solid calcium source, and modified calcium stearate. This not only reduces energy consumption in the early stage of grinding and improves grinding efficiency, but also helps to improve the early strength of the prepared cement clinker. This is because: First, during the grinding process after the mother liquor and tetraethyl orthosilicate penetrate into the cement clinker, hydrogen peroxide decomposes under the heat generated by grinding to produce oxygen and water. Tetraethyl orthosilicate, upon contact with water, hydrolyzes in the alkaline environment of the cement clinker to form nano-silica and ethanol. On one hand, the mixture of ethanol and oxygen inside the cement clinker expands in volume under the heat of grinding, causing cracking and increasing the number of cracks in the cement clinker, thus accelerating its fracture under grinding. On the other hand, the localized high temperature generated by grinding causes a micro-explosion effect in the mixture, thereby accelerating the fracture of the cement clinker and improving grinding efficiency. The above process effectively improves the grinding efficiency of cement clinker in the early stage of grinding and reduces energy consumption. Secondly, the nano-silica particles formed by the hydrolysis of tetraethyl orthosilicate have high reactivity. Together with the solid calcium source, they can effectively improve the early strength of the cement clinker prepared by this invention. This is because when preparing cement-based materials using the cement clinker, the nano-silica particles and solid calcium source can rapidly hydrate under the action of mixing water during the early hydration stage of the cement clinker to form hydrated calcium silicate cementitious components. This not only increases the content of cementitious components in the early hardening stage of the cement-based material, but also acts as nucleation centers to help induce the hydration reaction, thereby improving early strength. Thirdly, the modified calcium stearate can effectively improve the grinding efficiency of cement clinker. This invention first utilizes the complexation effect of the calcium stearate and polycarboxylate superplasticizer to load the polycarboxylate superplasticizer onto the calcium stearate. When this modified calcium stearate is added to cement clinker, it can complex with the calcium ions on the cement clinker particles through the carboxyl groups of the polycarboxylate superplasticizer, thereby connecting the calcium stearate to the surface of the cement clinker particles and grinding them simultaneously. This reduces the attraction between cement clinker particles, reduces agglomeration, improves dispersibility, and thus improves grinding efficiency. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 The image shows a sample of a mixture of hydrogen peroxide and ethylene glycol prepared in Example 1 below.

[0020] Figure 2 The image shows a sample of modified calcium stearate powder prepared in Example 1 below. Detailed Implementation

[0021] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0022] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as those skilled in the art. All reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they shall be used in accordance with conventional methods in the art or as per the product instructions.

[0023] Furthermore, any methods and materials similar to or equivalent to those described herein can be applied to the method of this invention. The preferred embodiments and materials described in this invention are for illustrative purposes only. The technical solution of this invention will now be further described in conjunction with specific embodiments.

[0024] Example 1

[0025] The preparation of a grinding aid for producing cement clinker powder includes the following steps:

[0026] (1) Mix hydrogen peroxide and ethylene glycol and stir until homogeneous to form a mixture with a hydrogen peroxide solution mass fraction of 25% (e.g., Figure 1 (As shown), for later use.

[0027] (2) The polycarboxylate superplasticizer was mixed with 92% ethanol to form a modified solution with a superplasticizer mass fraction of 2.5%. Then, 500-mesh calcium stearate powder was mixed with the modified solution at a ratio of 1g:0.6ml and stirred evenly. Then, it was mechanically ground until the ethanol solution was completely evaporated to obtain modified calcium stearate powder (e.g., Figure 2 (As shown).

[0028] (3) Take the following raw materials: 24 parts by weight of the mixture described in this embodiment, 5 parts by weight of tetraethyl orthosilicate, 2 parts by weight of 500-mesh calcium hydroxide powder, 0.65 parts by weight of calcium lignosulfonate, and 1.7 parts by weight of the modified calcium stearate described in this embodiment. Mix the above raw materials and stir quickly to disperse them evenly to obtain the grinding aid.

[0029] The grinding aid prepared in this embodiment was uniformly sprayed at 0.35% by weight onto ordinary silicate cement clinker, and then allowed to stand for 1 minute. After that, it was ground in a ball mill for 30 minutes to obtain cement clinker powder. Then, the 45μm sieve residue and specific surface area of ​​the cement clinker powder were tested according to GB / T26748-2011 "Cement Grinding Aids" to measure the grinding aid effect. In addition, the 3-day compressive strength of the above cement clinker powder was tested according to GBT 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" to measure its early strength. The test results are shown in the table below:

[0030] .

[0031] Example 2

[0032] The preparation of a grinding aid for producing cement clinker powder includes the following steps:

[0033] (1) Mix hydrogen peroxide and propylene glycol and stir until homogeneous to form a mixture with a hydrogen peroxide solution mass fraction of 20%, and set aside.

[0034] (2) The polycarboxylate superplasticizer was mixed with 80% ethanol solution to form a modified solution with a superplasticizer mass fraction of 3.5%. Then, 600-mesh calcium stearate powder was mixed with the modified solution at a ratio of 1g:0.4ml and stirred evenly. Then, it was mechanically ground until the ethanol solution was completely evaporated to obtain modified calcium stearate powder.

[0035] (3) Take the following raw materials: 27 parts by weight of the mixture described in this embodiment, 6 parts by weight of tetraethyl orthosilicate, 2.4 parts by weight of 600-mesh calcium oxide powder, 0.75 parts by weight of sodium lignosulfonate, and 2 parts by weight of the modified calcium stearate described in this embodiment. Mix the above raw materials and stir quickly to disperse them evenly to obtain the grinding aid.

[0036] The grinding aid prepared in this embodiment was uniformly sprayed at 0.2% by weight onto ordinary silicate cement clinker, and then allowed to stand for 1 minute. After that, it was ground in a ball mill for 30 minutes to obtain cement clinker powder. Then, the 45μm sieve residue and specific surface area of ​​the cement clinker powder were tested according to GB / T26748-2011 "Cement Grinding Aids" to measure the grinding aid effect. In addition, the 3-day compressive strength of the above cement clinker powder was tested according to GBT 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" to measure its early strength. The test results are shown in the table below:

[0037] .

[0038] Example 3

[0039] The preparation of a grinding aid for producing cement clinker powder includes the following steps:

[0040] (1) Mix hydrogen peroxide and ethylene glycol and stir until homogeneous to form a mixture with a hydrogen peroxide solution mass fraction of 30%, and set aside.

[0041] (2) The polycarboxylate superplasticizer was mixed with 95% ethanol to form a modified liquid with a superplasticizer mass fraction of 2%. Then, 400-mesh calcium stearate powder was mixed with the modified liquid at a ratio of 1g:0.7ml and stirred evenly. Then, it was mechanically ground until the ethanol was completely evaporated to obtain modified calcium stearate powder.

[0042] (3) Take the following raw materials: 20 parts by weight of the mixture described in this embodiment, 3 parts by weight of tetraethyl orthosilicate, 1.5 parts by weight of 400-mesh calcium carbide slag powder, 0.5 parts by weight of sodium lignosulfonate, and 1 part by weight of the modified calcium stearate described in this embodiment. Mix the above raw materials and stir quickly to disperse them evenly to obtain the grinding aid.

[0043] The grinding aid prepared in this embodiment was uniformly sprayed at 0.4% by weight onto ordinary silicate cement clinker, and then allowed to stand for 1 minute. After that, it was ground in a ball mill for 25 minutes to obtain cement clinker powder. Then, the 45μm sieve residue and specific surface area of ​​the cement clinker powder were tested according to GB / T26748-2011 "Cement Grinding Aids" to measure the grinding aid effect. In addition, the 3-day compressive strength of the above cement clinker powder was tested according to GBT 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" to measure its early strength. The test results are shown in the table below:

[0044] .

[0045] Example 4

[0046] The preparation of a grinding aid for producing cement clinker powder includes the following steps:

[0047] (1) The polycarboxylate superplasticizer was mixed with 92% ethanol to form a modified liquid with a superplasticizer mass fraction of 2.5%. Then, 500-mesh calcium stearate powder was mixed with the modified liquid at a ratio of 1g:0.6ml and stirred evenly. Then, it was mechanically ground until the ethanol was completely evaporated to obtain modified calcium stearate powder.

[0048] (2) Take the following raw materials: 24 parts by weight of ethylene glycol, 5 parts by weight of tetraethyl orthosilicate, 2 parts by weight of 500-mesh calcium hydroxide powder, 0.65 parts by weight of calcium lignosulfonate, and 1.7 parts by weight of the modified calcium stearate described in this embodiment. Mix the above raw materials and stir quickly to disperse them evenly to obtain the grinding aid.

[0049] The grinding aid prepared in this embodiment was uniformly sprayed at 0.35% by weight onto ordinary silicate cement clinker, and then allowed to stand for 1 minute. After that, it was ground in a ball mill for 30 minutes to obtain cement clinker powder. Then, the 45μm sieve residue and specific surface area of ​​the cement clinker powder were tested according to GB / T26748-2011 "Cement Grinding Aids" to measure the grinding aid effect. In addition, the 3-day compressive strength of the above cement clinker powder was tested according to GBT 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" to measure its early strength. The test results are shown in the table below:

[0050] .

[0051] Example 5

[0052] The preparation of a grinding aid for producing cement clinker powder includes the following steps:

[0053] (1) Mix hydrogen peroxide and ethylene glycol and stir until homogeneous to form a mixture with a hydrogen peroxide solution mass fraction of 30%, and set aside.

[0054] (2) The polycarboxylate superplasticizer was mixed with 95% ethanol to form a modified liquid with a superplasticizer mass fraction of 2%. Then, 400-mesh calcium stearate powder was mixed with the modified liquid at a ratio of 1g:0.7ml and stirred evenly. Then, it was mechanically ground until the ethanol was completely evaporated to obtain modified calcium stearate powder.

[0055] (3) Take the following raw materials: 20 parts by weight of the mixture described in this embodiment, 1.5 parts by weight of 400-mesh calcium carbide slag powder, 0.5 parts by weight of sodium lignosulfonate, and 1 part by weight of the modified calcium stearate described in this embodiment. Mix the above raw materials and stir quickly to disperse them evenly to obtain the grinding aid.

[0056] The grinding aid prepared in this embodiment was uniformly sprayed at 0.4% by weight onto ordinary silicate cement clinker, and then allowed to stand for 1 minute. After that, it was ground in a ball mill for 25 minutes to obtain cement clinker powder. Then, the 45μm sieve residue and specific surface area of ​​the cement clinker powder were tested according to GB / T26748-2011 "Cement Grinding Aids" to measure the grinding aid effect. In addition, the 3-day compressive strength of the above cement clinker powder was tested according to GBT 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" to measure its early strength. The test results are shown in the table below:

[0057] .

[0058] Example 6

[0059] The preparation of a grinding aid for producing cement clinker powder includes the following steps:

[0060] (1) Mix hydrogen peroxide and ethylene glycol and stir until homogeneous to form a mixture with a hydrogen peroxide solution mass fraction of 25%, and set aside.

[0061] (2) The polycarboxylate superplasticizer was mixed with 92% ethanol to form a modified liquid with a superplasticizer mass fraction of 2.5%. Then, 500-mesh calcium stearate powder was mixed with the modified liquid at a ratio of 1g:0.6ml and stirred evenly. Then, it was mechanically ground until the ethanol was completely evaporated to obtain modified calcium stearate powder.

[0062] (3) Take the following raw materials: 24 parts by weight of the mixture described in this embodiment, 5 parts by weight of tetraethyl orthosilicate, 0.65 parts by weight of calcium lignosulfonate, and 1.7 parts by weight of the modified calcium stearate described in this embodiment. Mix the above raw materials and stir quickly to disperse them evenly to obtain the grinding aid.

[0063] The grinding aid prepared in this embodiment was uniformly sprayed at 0.35% by weight onto ordinary silicate cement clinker, and then allowed to stand for 1 minute. After that, it was ground in a ball mill for 30 minutes to obtain cement clinker powder. Then, the 45μm sieve residue and specific surface area of ​​the cement clinker powder were tested according to GB / T26748-2011 "Cement Grinding Aids" to measure the grinding aid effect. In addition, the 3-day compressive strength of the above cement clinker powder was tested according to GBT 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" to measure its early strength. The test results are shown in the table below:

[0064] .

[0065] Example 7

[0066] The preparation of a grinding aid for producing cement clinker powder includes the following steps:

[0067] (1) Mix hydrogen peroxide and propylene glycol and stir until homogeneous to form a mixture with a hydrogen peroxide solution mass fraction of 20%, and set aside.

[0068] (2) Take the following raw materials: 27 parts by weight of the mixture described in this embodiment, 6 parts by weight of tetraethyl orthosilicate, 2.4 parts by weight of 600-mesh calcium oxide powder, 0.75 parts by weight of sodium lignosulfonate, and 2 parts by weight of 600-mesh calcium stearate powder. Mix the above raw materials and stir quickly to disperse them evenly to obtain the grinding aid.

[0069] The grinding aid prepared in this embodiment was uniformly sprayed at 0.2% by weight onto ordinary silicate cement clinker, and then allowed to stand for 1 minute. After that, it was ground in a ball mill for 30 minutes to obtain cement clinker powder. Then, the 45μm sieve residue and specific surface area of ​​the cement clinker powder were tested according to GB / T26748-2011 "Cement Grinding Aids" to measure the grinding aid effect. In addition, the 3-day compressive strength of the above cement clinker powder was tested according to GBT 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" to measure its early strength. The test results are shown in the table below:

[0070] .

[0071] Example 8

[0072] The preparation of a grinding aid for producing cement clinker powder includes the following steps:

[0073] Take the following raw materials: 10 parts by weight of ethylene glycol, 10 parts by weight of triethanolamine, 3 parts by weight of tetraethyl orthosilicate, 1.5 parts by weight of 400-mesh calcium carbide slag powder, 0.5 parts by weight of sodium lignosulfonate, and 1 part by weight of 400-mesh calcium stearate powder. Mix the above raw materials and stir rapidly to disperse them evenly to obtain the grinding aid.

[0074] The grinding aid prepared in this embodiment was uniformly sprayed at 0.4% by weight onto ordinary silicate cement clinker, and then allowed to stand for 1 minute. After that, it was ground in a ball mill for 25 minutes to obtain cement clinker powder. Then, the 45μm sieve residue and specific surface area of ​​the cement clinker powder were tested according to GB / T26748-2011 "Cement Grinding Aids" to measure the grinding aid effect. In addition, the 3-day compressive strength of the above cement clinker powder was tested according to GBT 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" to measure its early strength. The test results are shown in the table below:

[0075] .

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A grinding aid for producing cement clinker powder, characterized in that, The grinding aid consists of: 20-27 parts by weight of a mixture of hydrogen peroxide and polyol, 3-6 parts by weight of tetraethyl orthosilicate, 1.5-2.4 parts by weight of solid calcium source, 0.5-0.75 parts by weight of lignin sulfonate, and 1-2 parts by weight of modified calcium stearate.

2. The grinding aid for producing cement clinker powder according to claim 1, characterized in that, The polyol includes at least one of ethylene glycol, propylene glycol, and glycerol.

3. The grinding aid for producing cement clinker powder according to claim 1, characterized in that, The solid calcium source includes at least one of calcium oxide, calcium hydroxide, and carbide slag.

4. The grinding aid for producing cement clinker powder according to claim 1, characterized in that, The particle size of the solid calcium source is not less than 400 mesh.

5. The grinding aid for producing cement clinker powder according to claim 1, characterized in that, The lignin sulfonate includes at least one of sodium lignin sulfonate and calcium lignin sulfonate.

6. The grinding aid for producing cement clinker powder according to claim 1, characterized in that, The modified calcium stearate is obtained by mixing calcium stearate with an ethanol solution of polycarboxylate superplasticizer and then grinding the mixture.

7. The grinding aid for producing cement clinker powder according to claim 6, characterized in that, The ratio of calcium stearate to polycarboxylate superplasticizer in ethanol solution is 1g:0.4~0.7ml.

8. The grinding aid for producing cement clinker powder according to claim 7, characterized in that, The mass fraction of polycarboxylate superplasticizer in the ethanol solution is 2-3.5%; the mass fraction of the ethanol solution is not less than 80%.

9. The grinding aid for producing cement clinker powder according to claim 6, characterized in that, The particle size of the calcium stearate is not less than 400 mesh.

10. The grinding aid for producing cement clinker powder according to any one of claims 1-9, characterized in that, The mass fraction of hydrogen peroxide solution in the mixture is 20-30%.

11. The method of using the grinding aid for producing cement clinker powder according to any one of claims 1-9, characterized in that, The process includes the following steps: spraying the grinding aid evenly onto the cement clinker and letting it stand until it is ready, then grinding can be carried out.

12. The method of using the grinding aid for producing cement clinker powder according to claim 11, characterized in that, The grinding aid is added to the cement clinker at a rate of 0.2 to 0.4% of its mass.

13. The method of using the grinding aid for producing cement clinker powder according to claim 11, characterized in that, The settling time is 1 to 2 minutes.

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