Cement grinding aid prepared from ethylene carbonate rectification residue and its preparation method

Abstract

The application discloses a cement grinding aid prepared from ethylene carbonate rectification residual liquid and a preparation method thereof, and the cement grinding aid comprises the following raw materials in percentage by weight: 5-80% of a polyhydric alcohol mixed solution; 0-30% of an alcohol amine; 0-16% of an industrial salt; and the rest is water; the ethylene carbonate rectification residual liquid is all recycled and treated to be used as the raw material of the cement grinding aid, the cement grinding aid with excellent grinding aid effect is produced while the zero discharge of the ethylene carbonate rectification residual liquid is realized, and a new way is provided for the treatment of the ethylene carbonate rectification residual liquid.

Description

Technical Field

[0001] This invention belongs to the field of cement grinding aid technology, specifically relating to a cement grinding aid prepared using ethylene carbonate distillation residue and its preparation method. Background Technology

[0002] Ethylene carbonate (EC) is a high-performance organic solvent capable of dissolving a variety of polymers. It can also serve as an organic intermediate, replacing ethylene oxide in dioxylation reactions, and is a primary raw material for the transesterification production of dimethyl carbonate. Furthermore, it is used as a raw material for the synthesis of furazolidone, a water glass slurry, and a fiber finishing agent. In addition, it is applied in lithium-ion battery electrolytes. Ethylene carbonate can also be used as an active intermediate in the production of lubricating oils and greases.

[0003] Common methods for synthesizing ethylene carbonate include the phosgene process, transesterification, haloalcohol process, direct oxidation of ethylene with carbon dioxide, cycloaddition of ethylene oxide with carbon dioxide, and urea alcoholysis. Currently, the ethylene oxide-carbon dioxide addition process is the most prevalent ethylene carbonate production technology both domestically and internationally. The distillation residue, the bottom liquid remaining after ethylene carbonate (EC) purification in the distillation column and which cannot be recycled, is classified as hazardous chemical waste. The conventional practice for handling ethylene carbonate distillation residue is either recycling by a qualified company or incineration, both of which increase production costs for enterprises.

[0004] For example, CN 116239444 A discloses a waste liquid recovery device and method for an ethylene carbonate plant, including the following steps: S1, catalyst preparation section: First, solid catalyst is added to the catalyst preparation tank (1) through the catalyst feeding port, then fresh water is introduced, and then the stirrer of the catalyst preparation tank (1) is turned on for mixing. After the solid catalyst is completely dissolved in the fresh water, the catalyst mixture is added to the reactor (2); S2, reaction section: After all the catalyst mixture prepared in step S1 is added to the reactor (2), the stirring motor inside the reactor (2) is turned on, and the catalyst mixture is heated. Then, the reaction pressure of the reactor (2) is adjusted by injecting nitrogen. Then, the raw material waste liquid is pumped into the reactor (2) for reaction. The reaction time of the reactor (2) is controlled at 2-5 hours. During the reaction, the following steps are generated: The carbon dioxide waste gas enters the waste gas treatment system. After the reaction is completed, the waste liquid material is pumped into the thin film evaporator (3). S3, Evaporation section: After the waste liquid material is pumped into the thin film evaporator (3) after the reaction is completed in step S2, the thin film evaporator (3) is started to evaporate the waste liquid material. After evaporation, the gas phase enters the distillation column (5) and the liquid phase enters the evaporator feed tank (4). S4, Distillation section: After the gas phase obtained by evaporation in step S3 enters the distillation column (5), the light component at the top of the distillation column (5) is condensed by the top condenser (6) and part of it is returned to the distillation column (5), and part of it enters the catalyst preparation tank (1). The side-stream product is condensed by the product condenser (7) and sent to the ethylene glycol product tank. The heavy component at the bottom of the column enters the evaporator feed tank (4) as waste liquid treatment, and the other part is heated by the reboiler (8) and returned to the bottom of the distillation column (5). This patent requires multiple processes to recycle ethylene carbonate waste liquid, which results in high recycling costs. Furthermore, the recycling process can only reduce the discharge of waste liquid, but cannot achieve zero discharge of waste liquid. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a cement grinding aid prepared using ethylene carbonate distillation residue and its preparation method. By recovering and treating all ethylene carbonate distillation residue and using it as raw material for the cement grinding aid, zero discharge of ethylene carbonate distillation residue is achieved while producing a cement grinding aid with excellent grinding effect, providing a new approach for the treatment of ethylene carbonate distillation residue.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a cement grinding aid prepared using ethylene carbonate distillation residue, wherein the cement grinding aid comprises the following raw materials in weight percentages:

[0008] Polyol mixed solution: 5-80%;

[0009] Alkylamines: 0-30%;

[0010] Industrial salt: 0-16%;

[0011] The rest is water;

[0012] The preparation method of the polyol mixed solution is as follows: mix the distillation residue of ethylene carbonate with water, add a catalyst, react at 80-95℃ for 0.5-3h, filter to remove the precipitate, and the resulting filtrate is the polyol mixed solution.

[0013] The cement grinding aid preferably comprises the following raw materials in weight percentage:

[0014] Polyol mixed solution: 20-50%;

[0015] Alkylamine: 10-20%;

[0016] Industrial salt: 8-16%;

[0017] The rest is water.

[0018] The catalyst is at least one of potassium hydroxide, sodium hydroxide, sodium methoxide, and potassium methoxide.

[0019] The catalyst is used at a rate of 2-10% of the mass of the ethylene carbonate distillation residue.

[0020] The mass ratio of the distillation residue of ethylene carbonate to water is 3:1 to 1:3.

[0021] The alkanolamine is any one or more of triethanolamine, diethanol monoisopropanolamine, triisopropanolamine, or monoethanol diisopropanolamine.

[0022] The industrial salt is any one or more of calcium chloride, sodium chloride, sodium sulfate, sodium formate, and sodium nitrate.

[0023] The distillation residue of ethylene carbonate is the bottom liquid remaining after the ethylene carbonate is purified by a distillation column from the reaction liquid of ethylene oxide and carbon dioxide to prepare ethylene carbonate.

[0024] The present invention also provides a method for preparing a cement grinding aid using ethylene carbonate distillation residue, the method comprising the following steps: mixing ethylene carbonate distillation residue with water, adding a catalyst, reacting at 80-95℃ for 0.5-3h, filtering to remove precipitates, the resulting filtrate being a polyol mixed solution; mixing the polyol mixed solution with an alkanolamine, industrial salt and water uniformly to prepare the cement grinding aid.

[0025] The amounts of each raw material are as follows: polyol mixed solution: 5-80%; alkanolamine: 0-30%; industrial salt: 0-16%; the remainder is water; preferably: polyol mixed solution: 20-50%; alkanolamine: 10-20%; industrial salt: 8-16%; the remainder is water.

[0026] The cement grinding aid prepared using ethylene carbonate distillation residue provided by this invention utilizes a polyol mixed solution formed after chemical degradation and filtration of the ethylene carbonate distillation residue, combined with a certain amount of alkanolamine and industrial salt, to prepare the cement grinding aid, providing a new approach to the treatment of ethylene carbonate distillation residue. Through long-term practice, the applicant has discovered that liquid grinding aids for cement are mainly composed of organic and inorganic components such as alkanolamine, polymeric polyol, polymeric alkanolamine, ethylene glycol, propylene glycol, glycerol, sodium fatty acid, calcium chloride, sodium chloride, sodium acetate, aluminum sulfate, calcium formate, calcium lignosulfonate, and sodium lignosulfonate. The distillation residue of ethylene carbonate contains ethylene glycol, diethylene glycol, EC, triethylene glycol, tetraethylene glycol, polyols, and catalysts. This invention uses a chemical reaction to convert EC and water back into diols. The EC catalyst metal ions precipitate as hydroxides, and after filtration, a mixed solution is formed mainly composed of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oligomeric polyols. This mixed solution is then used as a dispersion component in cement grinding aids, providing a new approach for the treatment of distillation residues of ethylene carbonate.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) This invention utilizes a polyol mixed solution formed by chemical degradation and filtration of ethylene carbonate distillation residue, combined with a certain amount of alkanolamine and industrial salt, to prepare cement grinding aid, providing a new approach for the treatment of ethylene carbonate distillation residue.

[0029] (2) This invention degrades ethylene carbonate into polyols through chemical degradation, which can be used in grinding aids; and precipitates the metal ions such as catalysts in the distillation residue of ethylene carbonate, which can be recycled after filtration. Attached Figure Description

[0030] Figure 1 The gas chromatogram is of the distillation residue of ethylene carbonate and a mixed solution of polyols.

[0031] Figure 2 Gas chromatographic data for the distillation residue of ethylene carbonate;

[0032] Figure 3 This is gas chromatographic data for a polyol mixture. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the embodiments.

[0034] Example 1

[0035] A cement grinding aid prepared using ethylene carbonate distillation residue is composed of the following raw materials by weight percentage: 23% polyol mixed solution, 14% sodium chloride, 20% diethanol monoisopropanolamine, and 43% water.

[0036] The preparation method of the polyol mixed solution is as follows: Ethylene carbonate distillation residue and water are mixed evenly at a mass ratio of 1:1. Potassium hydroxide (2% by mass of the ethylene carbonate distillation residue) is added, and the mixture is heated to 95°C and reacted at atmospheric pressure for 0.5 hours. The precipitate is removed by filtration, and the resulting filtrate is the polyol mixed solution. The gas chromatograms of the ethylene carbonate distillation residue and the polyol mixed solution are shown below. Figure 1 As shown, the gas chromatographic data of the distillation residue of ethylene carbonate are as follows: Figure 2 As shown, the gas chromatographic data of the polyol mixture solution are as follows: Figure 3 As shown, from Figures 1-3 As can be seen from the example, the preparation method provided in this embodiment converts EC in the distillation residue of ethylene carbonate into a diol.

[0037] Example 2

[0038] A cement grinding aid prepared using ethylene carbonate distillation residue is composed of the following raw materials by weight percentage: 25% polyol mixed solution, 14% sodium chloride, 5% sodium sulfate, 15% monoethanol diisopropanolamine, and 41% water.

[0039] The preparation method of the polyol mixed solution is as follows: the distillation residue of ethylene carbonate and water are mixed evenly at a mass ratio of 1:1, sodium hydroxide accounting for 5% of the mass of the distillation residue of ethylene carbonate is added, the mixture is heated to 85°C, reacted at normal pressure for 2 hours, and the precipitate is removed by filtration. The resulting filtrate is the polyol mixed solution.

[0040] Example 3

[0041] A cement grinding aid prepared using ethylene carbonate distillation residue is composed of the following raw materials in weight percentages: 29% polyol mixed solution, 16% calcium chloride, 7% sodium nitrate, 10% triethanolamine, 6% triisopropanolamine, and 32% water.

[0042] The preparation method of the polyol mixed solution is as follows: the distillation residue of ethylene carbonate and water are mixed evenly at a mass ratio of 1:2, sodium methoxide accounting for 7% of the mass of the distillation residue of ethylene carbonate is added, the mixture is heated to 80°C, reacted at normal pressure for 3 hours, and the precipitate is removed by filtration. The resulting filtrate is the polyol mixed solution.

[0043] Example 4

[0044] A cement grinding aid prepared using ethylene carbonate distillation residue is composed of the following raw materials by weight percentage: 40% polyol mixed solution, 10% sodium chloride, 10% sodium formate, 13% diethanolmonoisopropanolamine, and 27% water.

[0045] The preparation method of the polyol mixed solution is as follows: the distillation residue of ethylene carbonate and water are mixed evenly at a mass ratio of 1:3, potassium methoxide accounting for 10% of the mass of the distillation residue of ethylene carbonate is added, the mixture is heated to 90°C, reacted at normal pressure for 1 hour, and the precipitate is removed by filtration. The resulting filtrate is the polyol mixed solution.

[0046] Test case

[0047] 95% clinker and 5% desulfurized gypsum were mixed with blank (without grinding aid) and grinding aid samples obtained in Examples 1-4, respectively, and then ground. The grinding aid dosage was 0.1% of the cement clinker mass. After grinding for 30 minutes, the performance of the cement powder was tested, and the results are shown in Table 1.

[0048] The specific surface area of ​​cement powder with grinding aid was tested according to GB / T 8074-2008 "Determination of Specific Surface Area of ​​Cement - Blaine Method", the 45μm sieve analysis test was performed on the cement powder with grinding aid according to GB / T 1345-2005 "Test Method for Fineness of Cement - Sieve Analysis Method", and the strength of cement mortar was determined according to GB / T 26748-2011 "Cement Grinding Aids".

[0049] Table 1 Evaluation Results of Cement Grinding Aids

[0050]

[0051] As can be seen from the table above, the cement grinding aid prepared by using the technical solution of the present invention with ethylene carbonate distillation residue has a significant grinding aid effect and can significantly improve the 3-day and 28-day strength of cement.

[0052] The above-described detailed description of a cement grinding aid prepared using ethylene carbonate distillation residue and its preparation method is illustrative rather than limiting. Several embodiments may be listed within the defined scope. Therefore, variations and modifications that do not depart from the overall concept of the present invention should be within the protection scope of the present invention.

Claims

1. A cement grinding aid prepared from ethylene carbonate rectification raffinate, characterized in that, The cement grinding aid comprises the following raw materials in percentage by weight: polyhydric alcohol mixed solution: 5-80%; alcohol amine: 0-30%; industrial salt: 0-16%; the rest is water; the alcohol amine and the industrial salt are not 0 in amount; the preparation method of the polyhydric alcohol mixed solution is as follows: mixing the ethylene carbonate distillation residue with water, adding a catalyst, reacting at 80-95℃ for 0.5-3h, removing the precipitate by filtration, and the obtained filtrate is the polyhydric alcohol mixed solution; the catalyst is at least one of potassium hydroxide, sodium hydroxide, sodium methoxide and potassium methoxide; the ethylene carbonate distillation residue is the bottom liquid of a distillation column after purifying ethylene carbonate from a reaction liquid of ethylene oxide and carbon dioxide.

2. The cement grinding aid prepared from the ethylene carbonate rectification residue according to claim 1, characterized in that, The cement grinding aid comprises the following raw materials in percentage by weight: polyhydric alcohol mixed solution: 20-50%; alcohol amine: 10-20%; industrial salt: 8-16%; the rest is water.

3. The cement grinding aid prepared from the ethylene carbonate rectification residue according to claim 1, characterized in that, the catalyst is in an amount of 2-10% of the mass of the ethylene carbonate distillation residue.

4. The cement grinding aid prepared from ethylene carbonate rectification residue according to claim 1, characterized in that, the mass ratio of the ethylene carbonate distillation residue to water is 3:1-1:

3.

5. The cement grinding aid prepared from the ethylene carbonate rectification residue according to any one of claims 1-4, characterized in that, the alcohol amine is any one or more of triethanolamine, diethanol mono-isopropanolamine, tri-isopropanolamine or mono-ethanol di-isopropanolamine.

6. The cement grinding aid prepared from the ethylene carbonate rectification residue according to any one of claims 1 to 4, characterized in that, the industrial salt is any one or more of calcium chloride, sodium chloride, sodium sulfate, sodium formate and sodium nitrate.

7. The method of claim 1 to 6, wherein the cement grinding aid is prepared by using the ethylene carbonate rectification residue, and the method is characterized by, the preparation method comprises the following steps: mixing the ethylene carbonate distillation residue with water, adding a catalyst, reacting at 80-95℃ for 0.5-3h, removing the precipitate by filtration, and the obtained filtrate is the polyhydric alcohol mixed solution; mixing the polyhydric alcohol mixed solution with the alcohol amine, the industrial salt and water uniformly to prepare the cement grinding aid. ​

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