A method for preparing a solid cement grinding aid

Abstract

The application discloses a preparation method of a solid cement grinding aid, and belongs to the technical field of cement admixtures. Dust waste residue limestone powder in raw materials contains CaO and SiO2; waste residue magnesium aluminum silicate contains MgAl2SiO6; and the surface barrier of the three combined with hydrochloric acid can play a role of chemical modification and activation. The formed solid grinding aid plays a good role in grinding, yield increase and strength increase in cement production, so that activated solid grinding aid organic molecules are wrapped on the surfaces of cement clinker, pozzolana and gypsum particles, can directly contact the molecular film between the cement clinker, pozzolana and gypsum particles, and achieve the decomposition effect of the solid grinding aid on C3S and C3A in the cement in the cement grinding and hydration process. The solid grinding aid relatively adsorbed on the surfaces of C3S and C3A can further accelerate the hydration reaction, so that the yield, strength, compatibility, setting time and water demand of the cement and the like are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of cement admixture technology, and particularly relates to a method for preparing a solid cement grinding aid. Background Technology

[0002] In the cement production industry, grinding aids are widely used, playing a crucial role in improving cement grinding efficiency and enhancing cement performance. However, current grinding aid formulations often use triethanolamine as the main raw material, which brings numerous problems. In recent years, the market price of triethanolamine has continued to rise, directly leading to a significant increase in the cost of liquid grinding aids, which in turn increases the manufacturing cost of cement products for cement plants, placing considerable economic pressure on enterprises. Furthermore, liquid grinding aids themselves have significant drawbacks, such as high water content, which often results in poor performance in practical applications. When added to cement, the quality improvement effect is not obvious, and sometimes it can even interfere with the normal operation of the mill, reduce mill output, and affect the stability of cement quality. Therefore, the cement industry urgently needs to find a non-triethanolamine-based alternative to grinding aids to effectively reduce the cost of grinding aids and cement manufacturing, while ensuring high efficiency in the cement production process and stable product quality, thus promoting the sustainable development of the cement industry. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a method for preparing a solid cement grinding aid.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] This invention provides a solid cement grinding aid comprising the following raw materials by weight percentage: 85-90% limestone powder (dust and waste residue), 5-12% magnesium aluminum silicate (waste residue), and 3-5% hydrochloric acid.

[0006] Technical Principle: The raw materials of this invention contain limestone powder (dust and slag) with CaO and SiO2, and magnesium aluminum silicate (magnesium aluminum silicate) with MgAl2SiO6. Combined with hydrochloric acid, the surface layer of these three materials can play a role in chemical modification and activation. The resulting solid grinding aid plays a significant role in improving grinding efficiency, increasing production, and enhancing strength in cement production. The activated solid grinding aid's organic molecules are coated on the surface of cement clinker, volcanic ash, and gypsum particles, allowing direct contact with the molecular film between these particles. This enables the solid grinding aid to decompose C3S and C3A in cement during the cement grinding and hydration process. The solid grinding aid relatively adsorbed on the surface of C3S and C3A further accelerates their hydration reaction, effectively improving cement yield, strength, compatibility, setting time, and water requirement.

[0007] Furthermore, the mass content of CaO in the limestone powder of the dust waste residue is 18.61%, and the mass content of SiO2 is 16.52%.

[0008] Furthermore, the mass content of MgAl2SiO6 in the waste magnesium aluminum silicate is 76.31%.

[0009] Furthermore, the hydrochloric acid contains 36.5% HCl by mass.

[0010] Furthermore, the new mineral composition formed by the solid cement grinding aid contains 1.1-1.83% HCl by mass and 1-3% activated free water by mass.

[0011] Furthermore, the solid cement grinding aid comprises the following raw materials by weight percentage: 86-90% limestone powder (dust and waste residue), 5-10% magnesium aluminum silicate (waste residue), and 4-5% hydrochloric acid.

[0012] The present invention provides a method for preparing a solid cement grinding aid as described in the above technical solution, comprising the following steps: mixing limestone powder, magnesium aluminum silicate and hydrochloric acid, stirring and then activating by stacking to obtain the solid cement grinding aid.

[0013] Furthermore, the stirring speed is 125 r / min, and the stirring time is 3 min; and / or,

[0014] The temperature for the stacking activation is room temperature, and the stacking activation time is 24 hours.

[0015] The present invention also provides an application of the solid cement grinding aid as described in the above technical solution in cement production.

[0016] Furthermore, the amount of the solid cement grinding aid incorporated is 1-5% of the cement mass.

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

[0018] This invention utilizes a mixture of hydrochloric acid, dust-laden limestone powder, and magnesium aluminum silicate waste to activate and neutralize the mixture, thereby forming a novel solid cement grinding aid composed of minerals. This provides a pathway for the effective utilization of annually emitted dust-laden limestone powder, and offers a new product for the grinding aid industry. It also provides a high-performance grinding aid for the cement industry to increase production, save energy, improve product quality, and enhance economic benefits. This saves production costs for both grinding aid and cement companies, while increasing output and quality.

[0019] The main raw materials of the solid cement grinding aid of this invention are dust waste limestone powder and waste magnesium aluminum silicate, which realizes the transformation of waste into treasure. Compared with liquid cement grinding aids made of 100% natural materials and other expensive products on the market, it significantly reduces manufacturing costs and can be widely used in cement products, achieving energy conservation and emission reduction, reducing the emission of harmful gases such as CO2 and CS2, and protecting the ecological environment.

[0020] The solid cement grinding aid product of this invention points the way for the efficient resource utilization and upgrading of the grinding aid industry, and is conducive to the development of the grinding aid industry. It can 100% replace traditional liquid grinding aids in cement products and has the advantages and characteristics of high grinding efficiency, high cement hydration strength, low water demand, normal to slightly fast setting time, low drying shrinkage, qualified stability, and high fluidity of cement mortar.

[0021] The quality technical indicators of the solid cement grinding aid provided by this invention are as follows: grinding effect: residue on a 45μm sieve: 6.5-10.0; standard consistency water requirement: 0.1-0.18%; initial setting time: 10-16 min; final setting time: 12-17 min; boiling safety: qualified; cement mortar fluidity: 103-115%; mortar shrinkage rate: 0.011-0.015% after 28 days; chloride ion content: 0.01%; pH value: 8.6-8.7; odor: qualified; cement mortar compressive strength: 108-117% after 3 days; 109-117% after 28 days. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to specific embodiments.

[0024] This invention provides a solid cement grinding aid comprising the following raw materials by weight percentage: 85-90% limestone powder, 5-12% magnesium aluminum silicate from waste residue, and 3-5% hydrochloric acid; more preferably: 86-90% limestone powder, 5-10% magnesium aluminum silicate from waste residue, and 4-5% hydrochloric acid.

[0025] In a preferred embodiment, the mass content of CaO in the dust waste limestone powder is 18.61%, and the mass content of SiO2 is 16.52%. The dust waste limestone powder in this invention originates from the waste residue discharged during dust collection in the limestone manufactured sand mining process. Using it in the preparation of solid cement grinding aids achieves comprehensive utilization and environmentally friendly disposal of the waste residue. This not only reduces the pressure of waste residue stockpiling and environmental risks but also realizes resource recycling and significantly reduces manufacturing costs.

[0026] In a preferred embodiment, the MgAl2SiO6 content in the waste magnesium aluminum silicate is 76.31%. The waste magnesium aluminum silicate in this invention originates from the waste residue discharged during the production of magnesium aluminum silicate products. Using it in the preparation of solid cement grinding aids achieves the transformation of waste into treasure, reduces the emission of harmful gases such as CO2 and CS2, and protects the ecological environment.

[0027] In a preferred embodiment, the hydrochloric acid contains 36.5% HCl by mass. This invention improves the cracking phenomenon in cement products caused by high alkali content in cement by using hydrochloric acid with a HCl content of 36.5% by mass.

[0028] In a preferred embodiment, the new mineral composition formed by the solid cement grinding aid has an HCl content of 1.1-1.83% and an activated free water content of 1-3%.

[0029] The present invention provides a method for preparing a solid cement grinding aid as described in the above technical solution, comprising the following steps: mixing limestone powder, magnesium aluminum silicate and hydrochloric acid, stirring and then activating by stacking to obtain the solid cement grinding aid.

[0030] In a preferred embodiment, the stirring speed is 125 r / min, and the stirring time is 3 min. The purpose of stirring in this invention is to enable a sufficient organic activation chemical reaction between the materials.

[0031] In a preferred embodiment, the stacking activation temperature is room temperature, and the stacking activation time is 24 hours. This invention facilitates the formation of new hydrated minerals and new activated free water through reactions between the stacked activated materials, thus contributing to the production of high-performance cement grinding aids.

[0032] The present invention also provides an application of the solid cement grinding aid as described in the above technical solution in cement production.

[0033] In a preferred embodiment, the cement is selected from silicate cement, ordinary cement, slag cement, fly ash cement, pozzolanic cement, or composite cement.

[0034] In a preferred embodiment, the amount of the solid cement grinding aid is 1-5% of the cement mass.

[0035] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased through commercial channels.

[0036] In the following examples and comparative examples, the limestone powder used for dust and waste residue was purchased from Xuyi County Mining Co., Ltd., the magnesium aluminum silicate waste residue was purchased from Huai'an Jingshen Co., Ltd., and the hydrochloric acid was purchased from Yixing Chemical Co., Ltd.

[0037] Example 1

[0038] A solid cement grinding aid is composed of the following raw materials in weight percentages: 85% limestone powder (from dust and waste residue), 12% magnesium aluminum silicate (from waste residue), and 3% hydrochloric acid; wherein the limestone powder contains 18.61% CaO and 16.52% SiO2; the magnesium aluminum silicate contains 76.31% MgAl2SiO6; and the hydrochloric acid contains 36.5% HCl.

[0039] The specific steps of the preparation method of the above-mentioned solid cement grinding aid are as follows: put the dust waste limestone powder, waste magnesium aluminum silicate and hydrochloric acid into a mixer and stir at 125 r / min for 3 min to make fine particles of solid cement grinding aid. Then, stack them at room temperature for 24 h to activate them, and obtain a new solid cement grinding aid with a HCl mass content of 1.1% and an activated free water mass content of 1.1% in the mineral composition.

[0040] The solid cement grinding aid from Example 1 was used at an addition rate of 1% in the production of silicate cement, ordinary cement, slag cement, fly ash cement, pozzolanic cement, and composite cement. The results were then tested according to the technical requirements in the national standard GB / T26748-2011 for cement grinding aids. The test results are shown in Table 1.

[0041] Table 1

[0042]

[0043]

[0044] Example 2

[0045] A solid cement grinding aid is composed of the following raw materials by weight percentage: 86% limestone powder (from dust and waste residue), 10% magnesium aluminum silicate (from waste residue), and 4% hydrochloric acid; wherein the limestone powder contains 18.61% CaO and 16.52% SiO2; the magnesium aluminum silicate contains 76.31% MgAl2SiO6; and the hydrochloric acid contains 36.5% HCl.

[0046] The specific steps of the preparation method of the above-mentioned solid cement grinding aid are as follows: put the dust waste limestone powder, waste magnesium aluminum silicate and hydrochloric acid into a mixer and stir at 125 r / min for 3 min to make fine particles of solid cement grinding aid. Then, stack them at room temperature for 24 h to activate them, and obtain a new solid cement grinding aid with a HCl mass content of 1.46% and an activated free water mass content of 1.9% in the mineral composition.

[0047] The solid cement grinding aid from Example 2 was used at a dosage of 3% in the production of silicate cement, ordinary cement, slag cement, fly ash cement, pozzolanic cement, and composite cement. The results were then tested according to the technical requirements in the national standard GB / T26748-2011 for cement grinding aids. The test results are shown in Table 2.

[0048] Table 2

[0049]

[0050]

[0051] Example 3

[0052] A solid cement grinding aid is composed of the following raw materials in weight percentages: 90% limestone powder (from dust and waste residue), 5% magnesium aluminum silicate (from waste residue), and 5% hydrochloric acid; wherein the limestone powder contains 18.61% CaO and 16.52% SiO2; the magnesium aluminum silicate contains 76.31% MgAl2SiO6; and the hydrochloric acid contains 36.5% HCl.

[0053] The specific steps of the preparation method of the above-mentioned solid cement grinding aid are as follows: put the dust waste limestone powder, waste magnesium aluminum silicate and hydrochloric acid into a mixing mixer, stir at 125 r / min for 3 min to make fine particles of solid cement grinding aid, and stack them at room temperature for 24 h to obtain a new solid cement grinding aid with a HCl mass content of 1.83% and an activated free water mass content of 2.9% in the mineral composition.

[0054] The solid cement grinding aid from Example 3 was used at a dosage of 5% in the production of silicate cement, ordinary cement, slag cement, fly ash cement, pozzolanic cement, and composite cement. The results were then tested according to the technical requirements in the national standard GB / T26748-2011 for cement grinding aids. The test results are shown in Table 3.

[0055] Table 3

[0056]

[0057]

[0058] As shown in Tables 1-3, the solid cement grinding aid provided by this invention can replace the liquid grinding aids on the market for cement production. It has good grinding effect, high cement strength, low water demand, normal to slightly fast setting time, high fluidity, low drying shrinkage rate, and its quality exceeds the national standard technical requirements for grinding aids.

[0059] 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.

Claims

1. A solid cement grinding aid, characterized in that, The raw materials include the following weight percentages: 85-90% limestone powder, 5-12% magnesium aluminum silicate, and 3-5% hydrochloric acid; The mass content of MgAl2SiO6 in the waste magnesium aluminum silicate is 76.31%; The new mineral composition formed by the solid cement grinding aid has an HCl content of 1.1-1.83% and an activated free water content of 1-3%. The preparation method of the solid cement grinding aid includes the following steps: mixing limestone powder, magnesium aluminum silicate and hydrochloric acid, stirring and then activating by stacking to obtain the solid cement grinding aid; the stacking activation temperature is room temperature and the stacking activation time is 24 hours. The limestone powder in the dust waste residue contains 18.61% CaO and 16.52% SiO2 by mass.

2. The solid cement grinding aid according to claim 1, characterized in that, The hydrochloric acid contains 36.5% HCl by mass.

3. The solid cement grinding aid according to claim 1, characterized in that, The solid cement grinding aid comprises the following raw materials by weight percentage: 86-90% limestone powder (dust and waste residue), 5-10% magnesium aluminum silicate (waste residue), and 4-5% hydrochloric acid.

4. The solid cement grinding aid according to claim 1, characterized in that, The stirring speed is 125 r / min, and the stirring time is 3 min.

5. The application of the solid cement grinding aid as described in any one of claims 1 to 4 in cement production.

6. The application according to claim 5, characterized in that, The amount of the solid cement grinding aid added is 1 to 5% of the cement mass.

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