New generation diethylene glycol monohexanoate and / or diethylene glycol dihexanoate based grinding aid with high grinding efficiency, strength enhancer

Abstract

The present invention relates to the grinding additive used in the cement industry, in the clinker grinding phase of cement production and in the preparation of cementitious systems. In particular, the present invention relates to a grinding aid consisting of diethylene glycol monohexanoate and / or diethylene glycol dihexanoate composition obtained by esterification reaction of diethylene glycol with hexanoic acid, and a method of synthesis.

Description

[0001] New Generation Diethylene Glycol Monohexanoate and / or Diethylene Glycol Dihexanoate Based Grinding Aid with High Grinding Efficiency, Strength Enhancer

[0002] Field of the Invention

[0003] The present invention relates to the grinding additive used in the cement industry, in the clinker grinding phase of cement production and in the preparation of cementitious systems. In particular, the present invention relates to a grinding aid consisting of diethylene glycol monohexanoate and / or diethylene glycol dihexanoate composition obtained by esterification reaction of diethylene glycol with hexanoic acid, and a method of synthesis.

[0004] State of the Art

[0005] Events such as greenhouse gas emissions, air pollution and climate change are among the main factors that cause global problems. In the process of solving these problems, issues such as developing alternatives to products that cause CO2 emissions during production, renewable energy sources and energy efficiency have gained importance.

[0006] The cement industry causes great damage to the environment in terms of energy, raw material consumption and CO2 emissions. The amount of electricity consumed in the cement industry constitutes 2% of the electricity used worldwide and 5% of the electricity used in industry. However, it accounts for 5-7% of global CO2 emissions. While approximately 1 ,2 tons of raw materials and 130 kWh of energy are consumed to produce one ton of cement, approximately 1 ton of CO2 is produced as a result. According to the Paris climate agreement, greenhouse gas emissions are expected to be reduced by 50% in 2030 and completely to zero in 2050. In this regard, energy efficiency is of great importance in the production processes of products that cause greenhouse gas emissions during production. In cement production, approximately 35% of the energy consumed is spent in the clinker grinding phase. In addition, a significant part of the energy consumed in the grinding stage is wasted by turning into heat, sound and vibration. As a result of the studies carried out to reduce both the energy consumption and cost in question and to reduce the amount of CO2 emitted to the environment, the use of grinding aid (GA) has come to the agenda.

[0007] GAs (grinding aid) are adsorbed on the surfaces of grains with the help of high polarity functional groups (-OH, -NH2, -COOR, -SO3 etc.) they contain. Adsorbed GAs neutralize the electrical charges on the surface, preventing the cracks formed in the clinker from closing, preventing the particles from coming together and sticking to the mill surface and / or balls, thus ensuring grinding efficiency.

[0008] It is known that the cement grains produced by the use of GA have different surface energy even though they have the same Blaine fineness value. This situation significantly affects the hydration reactions of cement and cement-additive compatibility. In addition, it has been explained that cements produced by GA consist of smaller and smoother / angular-free grains. This situation may bring with it some negativities.

[0009] In the present art, cement grinding aids are typically selected from the class containing glycols, amines, or amino alcohols, such as alkylene glycols. For example, the grinding additive mentioned in European patent EP3019455B1 comprises at least one aminoalcohol and at least one substance selected from chlorides, thiocyanates, nitrates, nitrites and hydroxides which accelerate cement hydration and the concrete admixture comprises a reaction product of at least one calcium compound with at least one silicon compound selected from a silicon dioxide compound, a silica compound and a silicate compound.

[0010] However, with the developing technology, it has been determined that the performances of the existing GAs are insufficient and there is a significant gap in their development. As a result due to the abovementioned disadvantages and the insufficiency of the current solutions regarding the subject matter, a development is required to be made in the relevant technical field.

[0011] Purpose of the Invention

[0012] The present invention aims to solve the abovementioned disadvantages by being inspired from the current conditions.

[0013] The purpose of the present invention is to provide a new grinding aid with improved grinding performance by changing one or two of the hydroxyl groups in the commercially widely used diethylene glycol additive as a result of esterification reaction with organic acid, forming an ester of higher polarity.

[0014] Another purpose of the invention is to increase the grinding performance and cementitious system properties of the DEG used as a GA while reducing the additive cost thanks to the grinding aid containing diethylene glycol monohexanoate and / or diethylene glycol dihexanoate obtained as a result of the esterification reaction of diethylene glycol with hexanoic acid.

[0015] In order to fulfill the aforementioned purposes, the invention is a new generation grinding aid with high grinding efficiency, strength enhancer, and comprises diethylene glycol monohexanoate and / or diethylene glycol dihexanoate obtained by esterification reaction of diethylene glycol with hexanoic acid.

[0016] According to one embodiment of the invention comprises diethylene glycol dihexanoate: diethylene glycol mono hexanoate in a ratio of 1 :1 to 1 :2 by weight.

[0017] According to one embodiment of the invention also comprises diethylene glycol and / or hexanoic acid.

[0018] According to one embodiment of the invention may comprise 15% diethylene glycol, 12% hexanoic acid, 37% diethylene glycol mono hexanoate, 36% diethylene glycol dihexanoate by weight.

[0019] In order to fulfill the purposes described above, the invention is a new generation grinding aid synthesis method with high grinding efficiency, strength enhancer, characterized by comprising the following process steps; i. Evaporating of its water by heating of diethylene glycol; ii. Lowering the temperature of the heated Diethylene glycol to 50-60 degrees Celsius and adding half of the hexanoic acid dropwise; iii. Then, heating again and adding catalyst before the temperature reaches 80 degrees Celsius; iv. Adding the remaining hexanoic acid dropwise; v. Continuing the reaction at approximately 105-115 degrees Celsius and removing the water formed with the ester by applying vacuum repeatedly after the second hour.

[0020] According to an embodiment of the invention, 45-55% Diethylene glycol, 45-55% Hexanoic acid and 1 -3% catalyst by weight can be used in the synthesis method.

[0021] According to an embodiment of the invention, 49% Diethylene glycol, 49% Hexanoic acid and 2% catalyst by weight can be used.

[0022] According to one embodiment of the invention, sulfuric acid can be used as the catalyst.

[0023] According to one embodiment of the invention, the reaction can be continued at about 1 10 degrees Celsius.

[0024] According to one embodiment of the invention, the reaction can be continued for 3 hours.

[0025] According to an embodiment of the invention, after the second hour of the reaction, vacuum is applied every 15 minutes and the water formed with the ester is removed.

[0026] The structural and characteristic features of the present invention will be understood clearly by the following figures and the detailed description made with reference to these figures and therefore the evaluation shall be made by taking these figures and the detailed description into consideration.

[0027] Figures to Help Understanding the Invention

[0028] Figure 1 .a. DEG, 1 b. theoretical modeling of the M-DEG of the present invention. Figure 2. FTIR analysis result graph of M-DEG of the present invention.

[0029] Figure 3. GC-MS chromatogram of the M-DEG molecules of the present invention and the DEG .

[0030] Figure 4.13C NMR spectrum of the M-DEG molecule of the present invention.

[0031] Figure 5.13C NMR spectrum of hexanoic acid suggested by the chemdraw program.

[0032] Figure 6.13C NMR spectrum of DEG molecule suggested by the chemdraw program.

[0033] Figure 7. Relative grinding efficiencies graph of DEG and M-DEG of the present invention.

[0034] Figure 8. Relative flow and consistency retention performance graph.

[0035] Detailed Description of the Invention

[0036] In this detailed description, the inventive modified DEG-containing grinding additive and preferred embodiments thereof are described only for a better understanding of the subject matter.

[0037] The invention relates to a new generation, diethylene glycol monohexaonate and / or diethylene glycol dihexaonate based grinding aid with high grinding efficiency, strength enhancer and synthesis method, which is obtained as a result of esterification reaction of diethylene glycol with hexanoic acid.

[0038] The diethylene glycol mono and dihexaonate based grinding facilitating additive production method of the invention comprises the process steps of; i. Evaporating of its water by heating diethylene glycol; ii. Lowering the temperature of the heated Diethylene glycol to 50-60 degrees Celsius and adding half of the hexanoic acid dropwise; iii. Then, heating again and adding catalyst before the temperature reaches 80 degrees Celsius; iv. Adding the remaining hexanoic acid dropwise; v. Continuing the reaction at 105-115 degrees Celsius and removing the water formed with the ester by applying vacuum repeatedly after the second hour.

[0039] In the method of the invention, the presence of process step (i) is necessary to increase the degree of realization of the reaction. Since water is formed as a result of esterification, the presence of water in the environment affects the degree and speed of the reaction. DEG boiling point is 245C. Heating up to 100 C can be done to remove water.

[0040] In the method of the invention, if hexanoic acid is suddenly added in the process step (ii), a titration reaction may occur. That's why it should be added slowly.

[0041] In the method of the invention, the highest efficiency was achieved when sulfuric acid was used as the catalyst in the process step (iii). In order for sulfuric acid to function as a catalyst, the temperature should not exceed 80 degrees at the time of addition.

[0042] In the process step (iv) of the method of the invention, the remainder of the hexanoic acid is added slowly in order for the esterification reaction to occur successfully. Hexanoic acid should not be added when the temperature of DEG is above 80 degrees. Chemicals added to the reactor should be added dropwise.

[0043] In the process step (v) of the method of the invention, reaction time and reaction temperature are the parameters that must be taken into consideration for the formation of reaction products. In the method of the present invention, the highest efficiency was achieved by continuing the reaction at about 110 C for 3 hours and vacuuming every 15 minutes after the second hour to remove the water formed with the ester.

[0044] In order to achieve an efficient reaction within the scope of the invention, 45-55% Diethylene glycol, 45-55% Hexanoic acid, 1 -3% Sulfuric acid by weight are used in the total input composition.

[0045] In a preferred embodiment of the invention, 49% Diethylene glycol, 49% Hexanoic acid, 2% Sulfuric acid by weight are used in the total input composition.

[0046] Diethylene glycol is widely used as GA. DEG comprises 2 OH groups. Since the carboxyl group contained in acetic acid has a higher polarity than the OH group, modified DEG is synthesized by replacing the saddle with the OH group in the esterification reaction. Preliminary tests were carried out to ensure suitable conditions for the synthesis to occur, and it was determined that the temperature should be kept around 110 degrees and sulfuric acid should be used as a catalyst. DEG mono hexanoate (2-(2-hydroxyethoxy) ethyl hexanoate) and modified DEG products comprising DEG dihexanoate (oxybis(ethane-2,1-dihyl) dihexanoate) formed as a result of DEG esterification reaction were carried out via the synthesis scheme shown below.

[0047] 2-(2-hydroxyethoxy)ethyl hexaonate oxybis(ethane-2,1 -diyl)dihexaonate

[0048] In alternative applications, esters with higher polarity can be created by modifying the functional groups of GAs comprising hydroxyl groups with this method. Experimental Studies

[0049] First of all, 1 :1 molar DEG:Hexanoic acid and 2% of the total mass of sulfuric acid were weighed. First, the water contained in the DEG solution was separated. Then, the temperature of the DEG was expected to drop to 50-60 degrees. When the temperature reached the desired level, half of the hexanoic acid was added to the DEG and the temperature began to be increased while the mixing process continued with the help of a magnetic fish. Sulfuric acid was added dropwise before the temperature reached 80 degrees. After the reaction continued for a while, the remaining hexanoic acid was added dropwise. The temperature was fixed at 110 degrees and the reaction was continued for 3 hours. At the end of 2 hours, the water resulting from the ester formed was removed from the environment by vacuuming. The reaction was terminated when no water was seen coming out of the vacuum after 3 hours.

[0050] Analysis Results

[0051] The structures of DEG and M-DEG molecules were modeled, and the electron densities of the molecules and the charge values of the electronegative atoms were calculated. By establishing a connection between these calculations and the adsorption power, the grinding aiding powers of the obtained materials were evaluated, and it was aimed to theoretically support the experimental results obtained.

[0052] In this context, the Gaussian 09 program, which has been used extensively by chemists in recent years, was used. The optimizations of the molecules were made in the gas phase environment using the DFT / B3LYP method and the 6-311 ++G(d,p) basis set. Additionally, nbo loads were calculated using the pop=nbo keyword. The optimized structures of the resulting molecules are given in Figure 1 . As can be seen from the figure, the Modified DEG molecule subject to the invention has a higher electronegativity value.

[0053] Various analyzes were carried out to prove that the synthesized contribution was successfully synthesized. The results and comments of the analyzes are given below.

[0054] Fourier Transform Infrared Spectroscopy (FTIR) Analysis The pH value of the synthesized M-DEG contribution was measured as 5,32 by pH meter. The FTIR analysis result of the synthesized additive is shown in Figure 2.

[0055] The fact that the carbonyl stretching vibration observed around 1700 cm-1in hexanoic acid and the diffuse OH band observed around 3300 cm-1in the spectrum of the DEG molecule were observed simultaneously in the FTIR spectrum of the M-DEG molecule supports the formation of the M-DEG molecule as a result of the synthesis.

[0056] Gas chromatography mass spectrometry (GC-MS) Analysis

[0057] In order to confirm that the synthesis product was realized, GC-MS spectra of DEG and M-DEG molecules were taken. A method suitable for similar molecules has been determined in the literature. The resulting GC-MS chromatogram is given in Figure 3. The black chromatogram given in Figure 3 belongs to the DEG molecule, and the red chromatogram belongs to the product. When the black chromatogram is scanned in the device library, it is seen that it belongs to DEG. However, no equivalent of the chromatogram of the product was found in the library. However, when both chromatograms were compared, a new peak was observed at the 18th and 25th minute. It was determined that in this peak environment, there was a product other than DEG with a larger molecular weight than DEG. The percentages of the product obtained are shown in Table 2.

[0058] Table 2. Percentages of the products formed and the minutes visible in the GC-MS analysis

[0059] These results support that the modified ester molecule is formed in both 1 :1 and 1 :2 ratios (Table 2). Nuclear Magnetic Resonance Spectroscopy (NMR) Analysis

[0060] Finally,13C-NMR analysis was performed on the product to support that the product obtained as a result of the reaction was M-DEG. The obtained13C NMR spectrum is shown in Figure 4.

[0061] The13C NMR spectra obtained by theoretical modeling of the13C NMR spectra of the starting materials hexanoic acid and DEG molecules and the product M-DEG molecule are also shown in Figure 5-6. When the spectra of the modeled molecules are examined, it is expected that the carbon peak of hexanoic acid will be observed only at a value of approximately 178 ppm. However, two carbon peaks at 175 and 178 ppm were observed in the experimental spectrum in Figure 5. These results support that the M-DEG molecule was obtained. According to the low peak observed at 178 ppm in the spectrum, it is thought that the molecule with a DEG:hexanoic acid ratio of 1 :2 is present in the environment.

[0062] Grinding Performance of Modified DEG

[0063] The grinding performance of the modified DEG according to dosage is given in Table 2. The relative grinding efficiencies of DEG and Modified DEG compared to the control cement without GA are shown in Figure 7.

[0064] Table 2. Grinding performance of modified DEG

[0065] Number of Grinding Energy Relative

[0066] Blaine revolutions Time (min) Spent (kWh) Energy fineness required for for target Efficiency value target Blaine Blaine (%)

[0067] (cm2 / g) fineness fineness

[0068] Control 3950 8830 126.1 52.96

[0069] DEG-0.025 3852 8400 120.0 50.38 4.87

[0070] DEG-0.05 3910 8210 117.3 49.24 7.02

[0071] DEG-0.1 3824 8200 117.1 49.18 7.13

[0072] M-DEG-0.025 3922 7750 110.7 46.48 12.23

[0073] M-DEG-0.05 3865 7600 108.6 45.58 13.93

[0074] M-DEG-0.1 3820 7800 111.4 46.78 11.66

[0075] As can be seen from the table and figure, the modification process applied to the DEG increased the grinding efficiency by approximately 100% compared to DEG.

[0076] The presence of both DEG contribution, mono ester and diester in the product obtained as a result of synthesis can be seen from the analysis results. It has been observed that the chemicals present in the resulting product show an unpredictable synergistic effect, causing an increase in performance. It has been determined that the obtained additives give positive results not only in grinding performance but also in flow and mechanical performances. The flow performance of the resulting product is shown in Table 3.

[0077] Table 3. Flow performances of the additives flow values at a constant PCE dosage (cm)

[0078] PCE Requirement for 20 40 60

[0079] 0 min

[0080] Target Flow (%) min min min

[0081] Control 0.12 24.0 19.5 20 16.8

[0082] DEG-0.025 0.12 21.4 18.2 15.7 15.3

[0083] DEG-0.05 0.13 21.6 16.9 14.9 13.7

[0084] DEG-0.1 0.14 21.3 16.7 14.6 13.2 M-DEG-0.025 0.09 22.9 19.8 16.0 13.7

[0085] M-DEG-0.05 0.07 20.3 17.8 15.8 14.2

[0086] M-DEG-0.1 0.08 21.0 19.3 18.1 16.7

[0087] As seen in Figure 8 and Table 3, the fact that the modified additive causes less PCE (Polycarboxylate ether) requirement for the target flow value and positively affects the thickening performance is thought to be due to the synergistic effect of the additive ingredients.

[0088] In Table 4, the 28-day compressive strength of the additives and their relative values compared to the control mixture are given. Table 4. 28-day compressive strength values of mixtures

[0089] Relative

[0090] Compressive

[0091] Compressive

[0092] Strength (MPa)

[0093] Strength (%)

[0094] Control 43.15 100

[0095] DEG-0.025 43.55 100.9

[0096] DEG-0.05 40.8 94.6

[0097] DEG-0.1 39.75 92.1

[0098] M-DEG-0.025 46.25 107.2

[0099] M-DEG-0.05 49.4 114.5

[0100] M-DEG-0.1 43.5 100.8

Claims

CLAIMS1. A new generation grinding aid with high grinding efficiency, strength enhancer, characterized by comprising; diethylene glycol monohexanoate and / or diethylene glycol dihexanoate obtained by esterification reaction of diethylene glycol with hexanoic acid.

2. The grinding aid according to claim 1 , characterized by comprising; diethylene glycol dihexanoate: diethylene glycol mono hexaonate in a ratio of 1 :1 to 1 :2 by weight.

3. The grinding aid according to claim 1 , characterized by comprising; diethylene glycol and / or hexanoic acid.

4. The grinding aid according to claim 3, characterized by comprising; 15% diethylene glycol, 12% hexanoic acid, 37% diethylene glycol mono hexanoate, 36% diethylene glycol dihexanoate by weight.

5. A new generation grinding aid synthesis method with high grinding efficiency, strength enhancer, characterized by comprising the following process steps; i. Evaporating of its water by heating diethylene glycol; ii. Lowering the temperature of the heated Diethylene glycol to 50-60 degrees Celsius and adding half of the hexanoic acid dropwise; iii. Then, heating again and adding catalyst before the temperature reaches 80 degrees Celsius; iv. Adding the remaining hexanoic acid dropwise; v. Continuing the reaction at approximately 105-115 degrees Celsius and removing the water formed with the ester by applying vacuum repeatedly after the second hour.

6. The method according to claim 5, characterized in that; 45-55% Diethylene glycol, 45-55% Hexanoic acid, 1-3% catalyst by weight are used.

7. The method according to claim 5, characterized in that; 49% Diethylene glycol, 49% Hexanoic acid, 2% catalyst by weight are used.

8. The method according to claim 5, characterized in that; sulfuric acid is used as catalyst.

9. The method according to claim 5, characterized in that; the reaction is continued at about 110 ‘C.

10. The method according to claim 5, characterized in that; the reaction is continued for 3 hours.

11. The method according to claim 5, characterized in that; the water formed together with the ester is drawn off by vacuuming every 15 minutes after the second hour of the reaction.

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