DRY GRINDING OF CLAY MINERAL, GROUND CLAY MINERAL, AND ITS USE IN CONSTRUCTION MATERIALS

Abstract

The use of a grinding additive during the dry grinding of clay mineral, wherein the grinding additive is selected from the group consisting of alkanolamines, glycols, glycerol, sugars, sugar acids, carboxylic acids or their salts, superplasticizers, superabsorbent polymers, or mixtures thereof. Construction materials also include a ground clay mineral including the additives and the use of the ground clay mineral.

Claims

1-16. (canceled)

17. A method to increase the efficiency of dry grinding of clay mineral, the method comprising dry grinding the clay mineral together with an additive selected from triisopropanolamine (TIPA), triethanolamine (TEA), diethanolisopropanolamine (DEIPA), ethanoldiisopropanolamine (EDIPA), lactic acid, malonic acid, adipic acid, citric acid, galactose, glucose, lactose, maltose, sucrose, fructose, or mixtures thereof.

18. The method according to claim 17, wherein the clay mineral is a low-temperature calcined clay.

19. The method according to claim 17, wherein the additive is selected from triisopropanolamine (TIPA), triethanolamine (TEA), diethanolisopropanolamine (DEIPA), ethanoldiisopropanolamine (EDIPA), or mixtures of at least one of TIPA, TEA, DEIPA, and EDIPA with at least one of diethylene glycol, glycerol, carboxylic acid, and sugar.

20. The method according to claim 17, wherein the additive is selected from triisopropanolamine (TIPA), triethanolamine (TEA), diethanolisopropanolamine (DEIPA), or is a mixture of DEIPA with a sugar, or is a mixture of TIPA with a sugar, or is a mixture of DEIPA with a carboxylic acid, or is a mixture of TIPA with a carboxylic acid.

21. The method according to claim 17, wherein the additive is a mixture of DEIPA or TIPA with a sugar, and the weight ratio of DEIPA or TIPA:sugar is 1:1.

22. The method according to claim 17, wherein the additive is a mixture of DEIPA or TIPA with citric acid.

23. The method according to claim 17, wherein an amount of water present during grinding is not higher than 1 w %, relative to a total dry weight of the clay mineral.

24. The method as claimed in claim 17, wherein the additive is added to the clay mineral before and/or during grinding in a total amount of between 0.001-3 w %, in each case relative to a total dry weight of the clay mineral.

25. The method as claimed in claim 17, wherein the grinding is done in an attrition mill or a compressive grinder.

26. A ground clay mineral obtained by dry grinding a clay mineral in the presence of a grinding additive selected form the group consisting of alkanolamines, glycols, glycerol, sugars, sugar acids, carboxylic acids or their salts, superplasticizers, superabsorbent polymers, or mixtures thereof.

27. The ground clay mineral according to claim 26, wherein the clay mineral is a calcined clay, and the grinding additive is selected from triisopropanolamine (TIPA), triethanolamine (TEA), diethanolisopropanolamine (DEIPA), or is a mixture of DEIPA with a sugar, or is a mixture of TIPA with a sugar, or is a mixture of DEIPA with a carboxylic acid, or is a mixture of TIPA with a carboxylic acid.

28. A construction material comprising the ground clay mineral as claimed in claim 26.

29. The construction material as claimed in claim 28 comprising a) 5-95 w % of a ground clay mineral obtained by dry grinding a clay mineral in the presence of a grinding additive selected form the group consisting of alkanolamines, glycols, glycerol, sugars, sugar acids, carboxylic acids or their salts, superplasticizers, superabsorbent polymers, or mixtures thereof; b) 5-95 w % of at least one mineral binder selected from the group consisting of cement, gypsum, lime, latent hydraulic binders, pozzolanes, and geopolymers; c) optionally 15-85 w % of aggregates; d) optionally 0.1-10 w % of further additives; and e) optionally water in an amount to realize a mass ratio of water:mineral binder between 0.1-0.8.

30. A method to increase the early strength and/or final strength of a cementitious material comprising a ground clay mineral, the method comprising (i) providing the ground clay mineral as claimed in claim 26, (ii) intermixing the ground clay mineral with at least one mineral binder, (iii) optionally intermixing the mixture obtained in step (ii) with aggregates and further additives, and (iv) optionally intermixing the mixture obtained in step (ii) or (iii) with water.

31. The method as claimed in claim 30, wherein the ground clay mineral comprises an additive selected from selected from triisopropanolamine (TIPA), triethanolamine (TEA), diethanolisopropanolamine (DEIPA), ethanoldiisopropanolamine (EDIPA), or mixtures of at least one of TIPA, TEA, DEIPA, and EDIPA with at least one of diethylene glycol, glycerol, carboxylic acid, and sugar, or mixtures thereof, which additive was added to the clay mineral prior and/or during the grinding of the clay mineral.

Description

EXAMPLES

[0136] The following table 1 shoes an overview of the raw materials used.

TABLE-US-00001 TABLE 1 raw materials Clay Type 1 Low-temperature calcined clay (kaolinitc); 46.8% SiO.sub.2, 31.9% Al.sub.2O.sub.3, 5.6% Fe.sub.2O.sub.3, 2.1% TiO.sub.2, 0.4% MgO, 0.3% CaO, 0.1% K.sub.2O, 0.1% Na.sub.2O Clay Type 2 Low-temperature calcined clay (kaolinitc); 52.4% SiO.sub.2, 25.6% Al.sub.2O.sub.3, 9.7% Fe.sub.2O.sub.3, 1.4% TiO.sub.2, 1% K.sub.2O, 0.3% MgO, 0.2% CaO, 0.1% Na.sub.2O Clay Type 3 Low-temperature calcined clay (kaolinitc); 54.2% SiO.sub.2, 29.5% Al.sub.2O.sub.3, 3.4% Fe.sub.2O.sub.3, 1% TiO.sub.2, 0.6% K.sub.2O, 0.3% MgO, 0.2% CaO, 0.1% Na.sub.2O Clay Type 4 Low-temperature calcined clay (kaolinitc); 65.9% SiO.sub.2, 19.1% Al.sub.2O.sub.3, 3.9% Fe.sub.2O.sub.3, 2% TiO.sub.2, 0.7% MgO, 0.2% CaO, 0.1% K.sub.2O, 0.1% Na.sub.2O Clay Type 5 Calcined clay (kaolinitc); 50.8% SiO.sub.2, 45.9% Al.sub.2O.sub.3, 1.2% TiO.sub.2, 0.7% Fe.sub.2O.sub.3, 0.2% CaO, 0.15% K.sub.2O, 0.14% MgO, 0.1% Na.sub.2O Clay Type 6 Calcined clay (kaolinitc); 64.7% SiO.sub.2, 23.6% Al.sub.2O.sub.3, 5.8% Fe.sub.2O.sub.3, 2.9% K.sub.2O, 1% TiO.sub.2, 0.5% MgO, 0.2% CaO, 0.2% Na.sub.2O TIPA Triisopropanolamine, Sigma-Aldrich, 95% purity TEA Triethanolamine, Sigma-Aldrich, >99% purity DEIPA Diethanolisopropanolamine, Sigma-Aldrich, 94% purity Citric Acid Sigma-Aldrich, 99% purity Fructose D-(?)-Fructose, Sigma-Aldrich, >99% purity

[0137] Measurement of Blaine surface was done according to standard NF EN 196-6.

[0138] Sieve analysis was done according to standard ASTM C136/C136M.

[0139] Determination of amount of material sticking to balls and vessel was determined by weighing.

[0140] Compressive strength was measured according to EN 12190 on 4?4?4 cm prisms after curing at 23? C./50% r.h. of a mixture consisting of 50 w % clay milled as per the respective example, 50 w % of slaked lime and mixed with water in a weight ratio of water:powder of 0.64 for 7d and 28d respectively.

Example 1

[0141] 90 g of the respective clay material as indicated in below table 2 were heated to 100? C. and were then charged into a ball mill. 260 g of steel balls were then added (vessel and balls were pre-heated to 100? C.). Then the respective grinding additives as shown in the following table 2 were added in an amount of 0.015 w % relative to the weight of the clay. All grinding additives were diluted with water prior to addition in an amount to introduce 0.06 w % of water relative to the clay. In case where a mixture of two grinding additives was used, each of the grinding additives was introduced in an amount of 0.015 w % relative to the weight of the clay and the mixture was diluted in water prior to addition in an amount to introduce 0.06 w % of water relative to the clay.

[0142] Milling was then effected for 5 minutes. After this time, a sample was taken for the analysis of Blaine surface and milling was continued for another 5 minutes. After the total milling time of 10 minutes, the Blaine surface of the resulting clay was measured, and the amount of material sticking to the balls and vessel was determined.

[0143] The following table 2 gives an overview of the results. Examples 1, 5, 9, 13, 17, and 24 are comparative examples not according to the invention.

TABLE-US-00002 TABLE 2 Results 1 2 3 4 5 6 7 8 Clay type 1 1 1 1 2 2 2 2 Grinding None TIPA DEIPA TEA None TIPA DEIPA TEA additive type Blaine @ 5 min 9000 9230 9360 9250 8030 9210 9550 9600 [g/cm.sup.2] Blaine @ 10 min 10000 11330 10540 10860 10000 10390 10700 10230 [g/cm.sup.2] Residue on 47 36 34 34 45 34 36 34 45 ?m sieve [%] Residue on 56 50 49 50 55 49 51 52 32 ?m sieve [%] Material 30.9 10.1 6.8 7.6 24.3 6.8 6.3 5.6 sticking.sup.*1 [%] Compressive 4 4.1 4.7 4.3 3.2 4.5 3.3 3.9 strength 7 d [MPa] Compressive 8.6 9.2 11.3 n.m. 8.9 12.6 11.3 11.3 strength 28 d [MPa] 9 10 11 12 13 14 15 16 Clay type 3 3 3 3 4 4 4 4 Grinding None TIPA DEIPA TEA None TIPA DEIPA TEA additive type Blaine @ 5 min 4760 6500 6250 6140 7320 8150 7960 7800 [g/cm.sup.2] Blaine @ 10 min 6690 8080 8110 8380 8920 9140 9390 9500 [g/cm.sup.2] Residue on 45 35 34 33 40 35 35 35 45 ?m sieve [%] Residue on 58 51 50 49 51 49 48 49 32 ?m sieve [%] Material 22.7 7 8.1 7.7 13.3 5.9 6.4 6.4 sticking.sup.*1 [%] Compressive 3.6 4.5 4.7 4.8 2.3 2.5 2.7 2.6 strength 7 d [MPa] Compressive 9.6 11.5 10.1 11.4 5.5 6.1 6.3 5.9 strength 28 d [MPa] 17 18 19 20 21 22 23 Clay type 5 5 5 5 5 5 5 Grinding None TIPA DEIPA TIPA & TIPA & DEIPA & DEIPA & additive type Citric Acid Fructose Citric Acid Fructose Blaine @ 5 min 3910 6870 8110 6610 7060 6350 7180 [g/cm.sup.2] Blaine @ 10 min 5370 11090 11640 10690 11280 10540 10320 [g/cm.sup.2] Residue on 57 30 33 28 25 34 23 45 ?m sieve [%] Residue on 76 59 58 59 57 59 54 32 ?m sieve [%] 24 25 26 27 28 29 30 Clay type 6 6 6 6 6 6 6 Grinding None TIPA DEIPA TIPA & TIPA & DEIPA & DEIPA & additive type Citric Acid Fructose Citric Acid Fructose Blaine @ 5 min n.m. 7830 7240 7470 7690 6970 7730 [g/cm.sup.2] Blaine @ 10 min 7670 9520 10230 9420 9530 9050 9140 [g/cm.sup.2] Residue on 17 13 13 14 16 15 12 45 ?m sieve [%] Residue on 40 n.m. 29 31 31 31 32 32 ?m sieve [%] n.m.: not measured

[0144] It can be seen from the above results that the various grinding additives tested are effective in increasing the fineness of clay minerals during grinding and/or reduce the grinding time needed to reach to a given fineness. The various grinding additives are also efficient in reducing the stickiness of material during grinding and/or of ground material. Finally, the various grinding additives tested are helpful to increase the compressive strength of a binder composition comprising the ground clay mineral and containing the respective grinding additive.