Polyacrylic acid grinding aid for enhanced cement powder flowability

Patent metadata

Field	Value
Publication number	US-2024208862-A1
Application number	US-202318390613-A
Country	US
Kind code	A1
Filing date	Dec 20, 2023
Priority date	Dec 20, 2022
Publication date	Jun 27, 2024
Grant date	—

Abstract

A method for grinding cement clinker particles, comprising: introducing to a composition comprising dry cement clinker particles, in a ball mill or roller mill, whereby said particles are ground to have a finer average particle size, an aqueous grinding additive composition comprising: from about 0.1 to about 15% by weight of at least one polyacrylic acid or a salt thereof; and water; and grinding the dry composition comprising the cement clinker particles and the aqueous grinding additive composition to produce a cement product having a pack set index (PSI) greater than that obtained when the polyacrylic acid is not present in the grinding additive.

First claim

What is claimed is:

1 . A method for grinding cement clinker particles, comprising:
introducing an aqueous grinding additive to a dry composition comprising cement clinker particles, in a ball mill or roller mill, whereby said particles are ground to have a finer average particle size, wherein the aqueous grinding additive composition comprises:
from about 0.1 to about 15% by weight of at least one polyacrylic acid or a salt thereof, wherein the polyacrylic acid has a weight average molecular weight of from 1,500 to 75,000 g/mol; and
water; and
grinding the dry composition comprising the cement clinker particles and the aqueous grinding additive composition to produce a cement product having a pack set index (PSI) greater than that obtained when the polyacrylic acid is not present in the grinding additive.

2 . The method of claim 1 wherein the aqueous grinding additive further comprises from about 0.5 to about 60% of at least one polycarboxylate ether comb polymer.

3 . The method of claim 1 further comprising the steps of determining the PSI of ground cement powder after the cement powder was ground in the presence of a grinding aid that did not comprise a polyacrylic acid polymer and adding polyacrylic acid to the grinding aid in an amount effective to increase the PSI.

4 . The method of claim 1 wherein the particles being ground comprise cement clinker and at least one of fly ash, granulated blast furnace slag, limestone, calcined clay, or natural pozzolan.

5 . The method of claim 1 wherein the aqueous grinding additive composition further comprises at least one of a glycol, glycerol, a defoamer, sugar, salt, acetic acid or an acetate salt.

6 . The method of claim 5 wherein glycol is present and the glycol comprises at least one selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, and tripropylene glycol.

7 . The method of claim 1 wherein the aqueous grinding additive composition further comprises a grinding additive selected from the group consisting of triethanolamine, triisopropanolamine, diethanolisopropanolamine, diisopropanolethanolamine, tetrahyroxyethylthylene diamine, an acetic acid or salt thereof, or mixtures thereof.

8 . The method of claim 2 wherein the at least one polycarboxylate ether comb polymer has a structure represented by Formula (I) or Formula (II):

wherein each R 1 independently represents a hydrogen atom or a methyl group (—CH 3 group);
M represents hydrogen atom, an alkali metal or an alkaline earth metal cation, ammonium or organic amine groups or a mixture thereof;
Alk represents a C 2 -C 10 alkylene group;
p represents an integer of 0-1;
x represents an integer of 1-10;
y represents a number of 0-300;
z represents a number of 1-300:
R 2 represents a hydrogen atom or a hydrocarbon group having 1-10 carbon atoms; and
“a” and “b” are numerical values representing molar percentage of the polymer's structure, wherein “a” is 30-90 and b is 10-70.

9 . The method of claim 8 wherein the AlkO represents ethylene oxide (“EO”) and propylene oxide (“PO”), wherein the molar percentage ratio of EO:PO is 90:10 to 100:0.

10 . The method of claim 8 wherein R 2 in structure (II) represents hydrogen atom or a hydrocarbon group having 1-4 carbon atoms; x represents an integer of 1 to 4; y represents a number of 0; and z represents a number of 5-300.

11 . The method of claim 5 wherein the aqueous grinding additive comprises sugar at a concentration of from 0.1-50% by weight, salt at a concentration of from 0.1-50% by weight, the defoamer at a concentration of from 0.05-10% by weight, and acetic acid and/or acetate salt at a concentration of from 0.1-50% by weight.

12 . The method of claim 5 wherein sugar is present and the sugar is at least one selected from the group consisting of sucrose, gluconic acid and/or salt thereof, corn syrup, and molasses.

13 . The method of claim 5 wherein salt is present and the salt is at least one selected from the group consisting of sodium chloride, calcium chloride, sodium thiocyanate, and calcium nitrate.

14 . The method of claim 2 wherein the at least one polycarboxylate ether comb polymer comprises a hydrocarbon-containing main chain carrying carboxylic groups and polyalkyl chains and 0.01 to 4% by weight relative to the weight of the polymer of antioxidant groups grafted to the main chain, wherein the antioxidant groups comprise an aromatic amine having the following structural Formula (III):

wherein R 3 is hydrogen or a saturated or unsaturated, straight or branched hydrocarbon-based chain, or one or more optionally fused aromatic rings, comprising 1 to 100 carbon atoms optionally interrupted by one or more heteroatoms such as O, S, N or P;
R 4 is independently of each other selected from hydrogen or a straight or branched hydrocarbon chain, saturated or unsaturated, or one or more optionally fused aromatic rings, comprising 1 to 100 carbon atoms, optionally interrupted by one or several heteroatoms such as O, S, N or P, and/or optionally substituted by one or more amine, alcohol, ketone, halogenated derivative, isocyanate, acetoacetonate, silanol, carboxylic acid ester and alcohol, epoxide, carbonate or mercaptan, phosphate, phosphonate, sulfate, sulfonate or carboxylate; and
F is an amino group, an alcohol, a ketone, a halogenated derivative, isocyanate, acetoacetonate, silanol, a carboxylic acid ester, a carboxylic alcohol, an epoxide, a carbonate or a mercaptan linked to the aromatic ring optionally by a straight or branched hydrocarbon chain, saturated or unsaturated having up to 100 carbon atoms.

15 . The method of claim 1 wherein the cement product has a PSI of from 5 to 8.

16 . The method of claim 15 wherein the cement product has a PSI of from 5 to 7.

17 . The method of claim 5 wherein the defoamer is present and the defoamer is triisobutyl phosphate.

18 . A method for grinding cement clinker particles, comprising:
determining the PSI of ground cement powder after the cement powder was ground in the presence of a grinding aid that did not comprise a polyacrylic acid polymer and adding polyacrylic acid to the grinding aid in an amount effective to increase the PSI greater than that obtained when the polyacrylic acid is not present in the grinding additive; introducing an aqueous grinding additive to a dry composition comprising cement clinker particles, in a ball mill or roller mill, whereby said particles are ground to have a finer average particle size, wherein the aqueous grinding additive composition comprises:
from about 3 to about 5% by weight of at least one polyacrylic acid or a salt thereof, wherein the polyacrylic acid has a weight average molecular weight of from 1,500 to 25,000 g/mol; and
water; and
grinding the dry composition comprising the cement clinker particles and the aqueous grinding additive composition to produce a cement product having a pack set index (PSI) greater than that obtained when the polyacrylic acid is not present in the grinding additive.

19 . The method of claim 18 wherein the aqueous grinding additive further comprises from about 0.5 to about 60% of at least one polycarboxylate ether comb polymer.

20 . The method of claim 18 wherein the aqueous gr

Assignees

• Gcp Applied Tech Inc

Inventors

• Detellis Joshua
• Thomas Jeffrey S
• Cheung Josephine H

Classifications

• C04B2103/50

  Defoamers, air detrainers · CPC title

• C04B16/04

  Macromolecular compounds (C04B16/02 takes precedence) · CPC title

• C04B28/04

  Portland cements · CPC title

• C04B2103/52

  Grinding aids; Additives added during grinding · CPC title

• C04B7/52 Primary

  Grinding {; After-treatment of ground cement} · CPC title