A cement raw material energy-saving additive, its preparation method and application

Abstract

This invention belongs to the field of cement production technology, specifically disclosing a cement raw meal energy-saving additive, its preparation method, and its application. The cement raw meal energy-saving additive comprises additive components and water, with the water accounting for 10-50% of the additive components by weight. The additive components include the following raw material components by weight: 10-60 parts of saponified waste alkali solution, 3-8 parts of sodium carbonate, 10-18 parts of organic acid salts, and 1-2 parts of regulator. When applied to cement production, this cement raw meal energy-saving additive can achieve good yield increases during the raw meal grinding stage and good energy-saving and quality-preserving effects during the calcination stage.

Description

Technical Field

[0001] This invention relates to the field of cement production technology, specifically to an energy-saving additive for cement raw materials, its preparation method, and its application. Background Technology

[0002] The cement production process is divided into three stages, referred to as "two grindings and one calcination". Specifically, the first stage is raw meal grinding, where calcareous raw materials, clayey raw materials, and a small amount of corrective materials are crushed or dried, then mixed and ground in a certain proportion to prepare raw meal with suitable composition and uniform quality. The second stage is raw meal calcination, where the ground raw meal is added to a cement kiln and calcined until partially melted to obtain cement clinker with calcium silicate as the main component. The third stage is clinker grinding, where an appropriate amount of gypsum is added to the clinker, and sometimes some mixed materials are also added, and they are ground together to obtain the final product, cement.

[0003] Cement production is an industry with low energy efficiency and high energy consumption. Therefore, reducing energy consumption while ensuring cement quality and production capacity is crucial for improving enterprise competitiveness, increasing economic benefits, and achieving sustainable development. Raw meal grinding is a vital step in cement production, and with the gradual improvement of grinding technology and mill structure, the performance requirements for cement admixtures in actual production applications are also gradually increasing. In recent years, some cement plants have begun to use energy-saving additives for cement raw meal, but research on these additives is currently limited. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems by providing a cement raw meal energy-saving additive, its preparation method, and its application. This cement raw meal energy-saving additive, when applied in cement production, can significantly increase production during the raw meal grinding stage and provide excellent energy-saving and quality-preserving effects during the calcination stage.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A cement raw material energy-saving additive, comprising additive components and water, wherein the mass of water is 10-50% of the mass of the additive components, and the additive components comprise the following raw material components in parts by weight: 10-60 parts of saponification waste alkali liquid, 3-8 parts of sodium carbonate, 10-18 parts of organic acid salts, and 1-2 parts of regulator.

[0007] Furthermore, the saponification waste alkali liquid is the saponification waste alkali liquid from cyclohexanone to caprolactam and / or the saponification waste alkali liquid from cyclohexane oxidation to cyclohexanone.

[0008] Furthermore, the organic acid salt is prepared by mixing sodium citrate and sodium formate in a mass ratio of 3:1.

[0009] Furthermore, the regulator is made by mixing sodium polystyrene sulfonate and carbonic acid, wherein the mass ratio of sodium polystyrene sulfonate to carbonic acid is 2:1.

[0010] Furthermore, the density of the cement raw material energy-saving additive is 1.22±0.03 g / cm³. 3 pH ≥ 10, solids content ≥ 36%.

[0011] The present invention also discloses a method for preparing the above-mentioned energy-saving additive for cement raw materials. The preparation method is as follows: the saponified waste alkali liquid, the sodium carbonate, the organic acid salt and the regulator are sequentially added to the water and stirred evenly.

[0012] The present invention also discloses a method for producing cement using the aforementioned cement raw meal energy-saving additive. The method involves incorporating the cement raw meal energy-saving additive into the cement raw meal for grinding, then calcining the ground raw meal to obtain clinker, and finally grinding the clinker.

[0013] Furthermore, the dosage of the energy-saving additive for cement raw materials is 0.5-1.5‰.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0015] 1. The components of this cement raw material energy-saving additive work synergistically to effectively aid grinding during the raw material milling stage, increasing the hourly output of the mill while maintaining the fineness of the raw material. During the calcination stage, it promotes the thermal decomposition of CaCO3, fully utilizing the heat from coal combustion to achieve coal savings. Furthermore, it lowers the activation energy for clinker formation, allowing the liquid phase to appear earlier and enabling the rapid and abundant formation of C3S in the clinker at low temperatures, thus improving clinker quality. Simultaneously, the prepared clinker exhibits a lower tendency for compaction and agglomeration, reducing cement adhesion to the walls and facilitating cement loading and unloading.

[0016] 2. The preparation method of the energy-saving additive for cement raw materials of the present invention is simple, easy to operate, and easy to promote industrialization. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments.

[0018] In particular, all features disclosed in this specification, or all steps in all methods or processes disclosed, may be combined in any way, except for mutually exclusive features and / or steps.

[0019] Unless otherwise stated, each feature disclosed in this specification (including any appended claims and abstract) is merely one example of a series of equivalent or similar features.

[0020] Example 1

[0021] This embodiment is a preliminary experiment. Through long-term formulation research, the inventors discovered that using a compound of saponification waste alkali liquid, sodium carbonate, organic acid salts, and regulators can effectively increase the hourly output during the raw material grinding stage and reduce coal consumption during the calcination stage. To this end, the inventors conducted the following research experiments:

[0022] raw material:

[0023] ① Organic acid salts: Sodium citrate and sodium formate are mixed evenly in a mass ratio of 3:1.

[0024] ②Regulator: Mix sodium polystyrene sulfonate and carbonic acid at a mass ratio of 2:1 until homogeneous.

[0025] ③ Energy-saving additive for cement raw materials: By weight, add 10 parts of saponification waste alkali solution, 3 parts of sodium carbonate, 10 parts of organic acid salts, and 1 part of regulator to an appropriate amount of water, stir evenly, so that the solid content is 36% and the density is 1.22±0.03g / cm³. 3 With a pH ≥ 10, the energy-saving additive for cement raw materials is obtained.

[0026] ④ Raw materials: including limestone, clay, siltstone, and iron slag powder. The raw material ratio is limestone: clay: siltstone: iron slag powder = 80:10:6:4. Its chemical composition is shown in Table 1 below.

[0027] Table 1. Chemical composition of raw materials (%)

[0028]

[0029] Using the above-mentioned raw materials as cement raw materials, the following experimental groups of additives were added to the raw materials at a dosage of 1.2‰. The raw materials were then subjected to grinding, calcination and clinker grinding processes to obtain cement products. The hourly output of raw materials and coal consumption of each group were tested.

[0030] Experimental Group 1: The admixture was a cement raw material energy-saving admixture;

[0031] Experimental group 2: The additives were organic acid salts and water;

[0032] Experimental group 3: The admixture consisted of regulator and water;

[0033] Experimental group 4: The additives were saponification waste alkali liquid + water;

[0034] Experimental group 5: The additive was sodium carbonate + water;

[0035] Experimental group 6: Water was added as an additive.

[0036] Based on testing and statistics, the hourly output of cement production raw material grinding stage and the coal consumption of the calcination stage for each group are shown in Table 2 below:

[0037] Table 2. Hourly output of raw materials and coal consumption for calcination in different experimental groups.

[0038] Group Experimental group 1 Experimental group 2 Experimental group 3 Experimental group 4 Experimental group 5 Experimental group 6 Taiwan hourly output t / h 265.5 245.1 251 246.7 247.3 240.2 Standard coal consumption (kg / t) 91.18 94.88 98.42 95.89 95.37 98.65

[0039] As shown in Table 2, using a cement raw meal energy-saving additive, which is a compound of saponified waste alkali liquid, sodium carbonate, organic acid salts and regulators, to grind raw meal can effectively increase the hourly output of the raw meal mill and reduce the coal consumption of calcination.

[0040] Example 2

[0041] As can be seen from the research conclusions of Example 1, the use of a cement raw meal energy-saving additive formulated from saponification waste alkali liquid, sodium carbonate, organic acid salts, and regulators can increase the hourly output of the raw meal mill and reduce the coal consumption for calcination. Therefore, the inventors studied the composition of organic acid salts in the raw meal cement additive, as follows:

[0042] raw material:

[0043] ① Cement raw material energy-saving additive one: By weight, add 45 parts of saponification waste alkali solution, 5 parts of sodium carbonate, 13 parts of organic acid salts, and 1.5 parts of regulator to an appropriate amount of water, stir evenly, and make the density 1.22±0.03g / cm³. 3 The cement raw material energy-saving additive is obtained by having a pH ≥ 10 and a solid content of 40%. The saponification waste alkali solution is the saponification waste alkali solution from the oxidation of cyclohexane to prepare cyclohexanone; the organic acid salt is prepared by mixing sodium citrate and sodium formate in a mass ratio of 3:1; and the regulator is prepared by mixing sodium polystyrene sulfonate and carbonic acid in a mass ratio of 2:1.

[0044] ② Cement raw material energy-saving additive II: Its composition is basically the same as that of cement raw material energy-saving additive I. The difference is that the organic acid salt is different. Its organic acid salt composition is: it is made by mixing sodium citrate and sodium acetate in a mass ratio of 3:1.

[0045] ③ Cement raw material energy-saving additive three: Its composition is basically the same as that of cement raw material energy-saving additive one. The difference is that the organic acid salt is different. Its organic acid salt composition is: it is made by mixing calcium sulfonate and sodium acetate in a mass ratio of 3:1.

[0046] ④ Cement raw material energy-saving additive four: Its composition is basically the same as that of cement raw material energy-saving additive one, the difference being that the organic acid salt is different. Its organic acid salt composition is: made only of sodium citrate.

[0047] ⑤ Energy-saving additive for cement raw materials: Its composition is basically the same as that of energy-saving additive for cement raw materials, except that the organic acid salts are different. Its organic acid salts are made only of sodium formate.

[0048] ⑥ Energy-saving additive for cement raw materials: Its composition is basically the same as that of energy-saving additive for cement raw materials, except that it does not contain organic acid salts.

[0049] Using the raw meal in Example 1 as cement raw material, cement raw meal energy-saving additives one to six as described above were added to the raw meal at a dosage of 1.2‰. The raw meal grinding, calcination and clinker grinding processes were carried out in sequence to obtain cement finished products. The raw meal hourly output, coal consumption and limestone decomposition temperature of each group were tested.

[0050] Based on the test statistics, the hourly output of cement production raw material grinding stage, the coal consumption of calcination stage, and the limestone decomposition temperature of each group are shown in Table 3 below:

[0051] Table 3. Hourly output of raw materials and coal consumption for calcination in different experimental groups

[0052] Group Additive 1 Additive 2 Additive 3 Additive 4 Additive 5 Additive 6 Taiwan hourly output t / h 266.8 263.7 254.3 257.2 252.7 253.7 Standard coal consumption (kg / t) 90.64 94.41 93.25 95.21 94.15 95.28 Decomposition temperature ℃ 842 849 851 850 854 855

[0053] As shown in Table 3, using sodium citrate and sodium formate as a compound organic acid salt can effectively promote the grinding effect of raw materials and the thermal decomposition of CaCO3, making full use of the heat of coal combustion, thereby achieving the effect of coal saving.

[0054] Example 3

[0055] The research conclusions of Example 2 show that adding an organic acid salt composed of sodium citrate and sodium formate to the cement raw meal energy-saving additive can increase the hourly output of the raw meal mill and reduce the coal consumption of calcination. Therefore, the inventors added organic acid salts made of sodium citrate and sodium formate in different mass ratios to the cement raw meal energy-saving additive in Example 2, and applied them to the raw meal in Example 1 for cement production. The effects of different proportions of organic acid salts made of sodium citrate and sodium formate on the hourly output and coal consumption of the raw meal were tested. The specific results are shown in Table 4:

[0056] Table 4. Raw material hourly output and calcination coal consumption for different proportions of organic acid salts.

[0057] Experimental Number Raw material mass ratio Taiwan hourly output t / h Standard coal consumption (kg / t) 1 Sodium citrate : sodium formate = 1:1 261.8 91.48 2 Sodium citrate : sodium formate = 2 : 1 263.7 92.05 3 Sodium citrate:sodium formate = 3:1 266.8 90.64 4 Sodium citrate:sodium formate = 4:1 262.7 91.88

[0058] As shown in Table 4, when sodium citrate and sodium formate are mixed in a mass ratio of 3:1, the thermal decomposition of CaCO3 is maximized, resulting in the best coal-saving effect.

[0059] Example 4

[0060] As can be seen from the research conclusions of Example 1, the use of a cement raw meal energy-saving additive formulated from saponification waste alkali liquid, sodium carbonate, organic acid salts, and regulators can increase the hourly output of the raw meal mill and reduce the coal consumption for calcination. Therefore, the inventors studied the composition of the regulators in the raw meal cement additive, as follows:

[0061] raw material:

[0062] ① Cement raw material energy-saving additive one: By weight, add 60 parts of saponification waste alkali solution, 8 parts of sodium carbonate, 18 parts of organic acid salts, and 2 parts of regulator to an appropriate amount of water, stir evenly, and make the density 1.22±0.03g / cm³. 3 The cement raw material energy-saving additive is obtained by having a pH ≥ 10 and a solid content of 42%. The saponification waste alkali liquid is the saponification waste alkali liquid from the oxidation of cyclohexane to prepare cyclohexanone; the organic acid salt is prepared by mixing sodium citrate and sodium formate in a mass ratio of 3:1; and the regulator is prepared by mixing sodium polystyrene sulfonate and carbonic acid in a mass ratio of 2:1.

[0063] ② Cement raw material energy-saving additive II: Its composition is basically the same as that of cement raw material energy-saving additive I, the difference being the regulator. Its regulator is composed of sodium polystyrene sulfonate and carbonic acid mixed in a mass ratio of 2:3.

[0064] ③ Energy-saving additive for cement raw materials III: Its composition is basically the same as that of energy-saving additive for cement raw materials I. The difference is that the regulator is different. Its regulator is made only of sodium polystyrene sulfonate.

[0065] ④ Cement raw meal energy-saving additive four: Its composition is basically the same as that of cement raw meal energy-saving additive one, the difference being that the regulator is different. Its regulator is made only of carbonic acid.

[0066] ⑤ Energy-saving additive for cement raw materials: Its composition is basically the same as that of energy-saving additive for cement raw materials, except that it does not contain regulators.

[0067] Using the raw meal in Example 1 as cement raw material, cement raw meal energy-saving additives one to five as described above were added to the raw meal at a dosage of 1.2‰. The raw meal was then ground to obtain raw meal powder. Each raw meal powder sample was vibrated with a shaking sieve for 10 minutes, weighed, and retained to one decimal place. The data are shown in Table 5 below.

[0068] Table 5 Comparison of raw material sieve residue in each group

[0069]

[0070] As shown in Table 5, the addition of a modifier made of sodium polystyrene sulfonate and carbonic acid significantly increased the amount of raw meal with a particle size ≤75μm (200 mesh) obtained by grinding, indicating that the grinding aid effect of the additive was significant.

[0071] Example 5

[0072] As can be seen from the research conclusions of Example 4, adding a regulator composed of polyethylene glycol and butanediol to the cement raw meal energy-saving additive can increase the hourly output of the raw meal mill and reduce the free calcium content after calcination. Therefore, the inventors added regulators made of polyethylene glycol and butanediol in different mass ratios to the cement raw meal energy-saving additive one in Example 2, and applied it to the raw meal in Example 1 for cement production. The effects of different proportions of regulators made of polyethylene glycol and butanediol on the hourly output and free calcium content of the raw meal were tested. The specific results are shown in Table 6:

[0073] Table 6. Raw material hourly output and calcination coal consumption for different proportions of organic acid salts.

[0074] Experimental Number Raw material mass ratio Taiwan hourly output t / h f-CaO% 1 Polyethylene glycol:butanediol = 2:1 263.8 0.997 2 Polyethylene glycol:butanediol = 2:2 264.5 1.012 3 Polyethylene glycol:butanediol = 2:3 265.1 0.954 4 Polyethylene glycol:butanediol = 2:4 262.7 0.976

[0075] As shown in Table 6, when the mass ratio of polyethylene glycol to butanediol is 2:3, the free calcium value is the lowest and the clinker firing quality is the best.

[0076] Example 6

[0077] As shown in the research conclusions of Example 1, the use of a cement raw meal energy-saving additive formulated from saponified waste alkali liquid, sodium carbonate, organic acid salts, and regulators can increase the hourly output of the raw meal mill and reduce the coal consumption for calcination. Therefore, the inventors studied the dosage of the raw meal cement additive, adding different dosages to the raw meal of Example 1 for cement production, and testing the effects of different dosages on limestone decomposition rate and clinker strength. Specific test results are shown in Table 7.

[0078] Table 7. Effects of different admixture amounts of energy-saving additives in cement raw materials on cement production.

[0079] Dosage per ‰ Limestone decomposition rate % Clinker 28-day compressive strength (MPa, ℃) 0.3 93.8 49.3 0.5 96.9 50.8 1.2 97.3 51.4 1.5 97.5 51.5 1.8 96.5 50.1 2.0 96.3 49.8

[0080] As shown in Table 7, when the cement additive dosage is 0.5-1.5‰, the decomposition rate of limestone during calcination and the compressive strength of clinker are optimal.

[0081] Furthermore, the cement clinker prepared using the cement raw meal additive of this invention was released from the cement silo after 9-11 days of storage. A total of 5 batches were released, and the silo walls were inspected after each release, with no cement lumps adhering to the walls. This indicates that the cement raw meal additive of this invention can reduce the compaction and agglomeration tendency of clinker, reduce cement adhesion to the walls, facilitate cement loading and unloading, improve the utilization rate of cement silos, greatly reduce silo cleaning operations, and keep the cement storage and release system in a good operating state.

[0082] The above description is a detailed description of the embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A cement raw material energy-saving additive, characterized in that, The energy-saving cement raw material additive includes additive components and water, wherein the mass of water is 10-50% of the mass of the additive components, and the additive components include the following raw material components in parts by weight: 10-60 parts of saponification waste alkali liquid, 3-8 parts of sodium carbonate, 10-18 parts of organic acid salts, and 1-2 parts of regulator; the organic acid salts are prepared by mixing sodium citrate and sodium formate in a mass ratio of 3:1; the regulator is prepared by mixing sodium polystyrene sulfonate and carbonic acid in a mass ratio of 2:

1.

2. The energy-saving additive for cement raw materials according to claim 1, characterized in that, The saponification waste alkali liquid is the saponification waste alkali liquid from the preparation of caprolactam from cyclohexanone and / or the saponification waste alkali liquid from the oxidation of cyclohexane to prepare cyclohexanone.

3. The energy-saving additive for cement raw materials according to claim 1, characterized in that, The density of the cement raw material energy-saving additive is 1.22±0.03 g / cm³. 3 pH ≥ 10, solid content ≥ 36%.

4. A method for preparing a cement raw meal energy-saving additive according to any one of claims 1-3, characterized in that, The preparation method is as follows: the saponification waste alkali solution, the sodium carbonate, the organic acid salt and the regulator are sequentially added to the water and stirred evenly.

5. A method for producing cement using the cement raw meal energy-saving additive as described in any one of claims 1-3, characterized in that, The method involves adding the cement raw meal energy-saving additive into the cement raw meal, grinding the raw meal, calcining the ground raw meal to obtain clinker, and finally grinding the clinker.

6. The method for producing cement using energy-saving additives for cement raw materials according to claim 5, characterized in that: The dosage of the energy-saving additive for cement raw materials is 0.5-1.5‰.

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