Impurity inerting composition

• US 8,834,626 B2
• Filed: 09/21/2005
• Issued: 09/16/2014
• Est. Priority Date: 09/21/2004
• Status: Active Grant

• Current Assignee: Holcim Technology, Ltd. (Holcim Limited)
• Original Assignee: Lafarge SA (Holcim Limited)
• Inventors: Jacquet, Alain, Watt, Olivier, Villard, Emmanuel
• Primary Examiner(s): ABU ALI, SHUANGYI
• Application Number:
  US11/575,607
• Publication Number:
  US 20080060556A1
• Time in Patent Office: 3,282 Days
• Field of Search: 106/802, 524/650
• US Class Current: 106/802
• CPC Class Codes: C04B 14/06 Quartz; Sand
• CPC Class Codes: C04B 20/02 Treatment
• CPC Class Codes: C04B 20/023 Chemical treatment
• CPC Class Codes: C04B 20/1018 with organic materials pigments or dyes C04B20/1096
• CPC Class Codes: C04B 2201/10 for the viscosity
• CPC Class Codes: C04B 2201/20 for the density
• CPC Class Codes: C04B 24/2652 Nitrogen containing polymers, e.g. polyacrylamides, polyacrylonitriles
• CPC Class Codes: C04B 24/30 Condensation polymers of aldehydes or ketones
• CPC Class Codes: C08G 12/16 Dicyandiamides
• CPC Class Codes: C08G 73/0226 Quaternisation of polyalkylene(poly)amines

Abstract

A method for inerting clays in sands which are intended for the preparation of hydraulic compositions, the method including a step of adding to the hydraulic composition, or to one of the constituents thereof, a composition which may include at least 50% by weight of a cationic polymer which has a density of cationic charges which is greater than 0.5 meq/g and an intrinsic viscosity which is less than 1 dl/g as an active substance. The hydraulic composition may be a concrete or a mortar.

Claims

1. A method for inerting clays in sands used in the preparation of a hydraulic composition, comprising the steps of:

adding the sands to the hydraulic composition, the sands having a clay content of from 0.5 to 5% by weight, and adding a composition to the hydraulic composition, or to one of the constituents thereof, the composition comprising at least 50% by weight of a cationic polymer having a density of cationic charges greater than 0.5 meq/g and an intrinsic viscosity less than 1 dl/g as an active substance.

2. A method according to claim 1, wherein the hydraulic composition is a concrete or a mortar.

3. A method according to claim 1, wherein the hydraulic composition contains no superplasticiser.

4. A method according to claim 1, wherein the composition is added to the hydraulic composition or to one of the constituents thereof by spraying.

5. A method according to claim 1, wherein the composition is used in a quarry.

6. A method according to claim 1, wherein the composition is used in a concrete mixing plant.

7. A method according to claim 1, wherein the cationic polymer has a density of cationic charges greater than 2 meq/g.

8. A method according to claim 1, wherein the cationic polymer has an intrinsic viscosity less than 0.6 dl/g.

9. A method according to claim 1, wherein the composition further comprises an anionic polymer.

10. A method according to claim 9, wherein the composition comprises a maximum of 50% by weight of anionic polymer as an active substance.

11. A method according to claim 9, wherein at least one of the cationic and anionic polymers has a comb structure.

12. A method according to claim 1, wherein the cationic polymer is linear.

13. A method according to claim 1, wherein the cationic polymer comprises cationic groups of quarternary amine.

14. A method according to claim 1, wherein the cationic polymer is prepared by condensation of epichlorohydrin with a dialkylamine.

15. A method according to claim 14, wherein the dialkylamine is dimethylamine.

16. A method according to claim 9, wherein the anionic polymer contains carboxylic groups.

17. A method according to claim 9, wherein the anionic polymer further comprises polyether groups.

18. A method according to claim 1, wherein the polymer is obtainable by condensation of dicyandiamide with formaldehyde, in the presence of:

A) a polyalkylene glycol.

19. A method according to claim 1, wherein the polymer is obtainable by condensation of dicyandiamide with formaldehyde, in the presence of:

B) a polyalkoxylated polycarboxylate.

20. A method according to claim 1, wherein the polymer is obtainable by condensation of dicyandiamide with formaldehyde, in the presence of:

C) an ammonium derivative.

21. A method according to claim 1, wherein the polyalkylene glycol has the following formula (I):

R²—

O—

[R²—

O]_n—

R³

where;

R¹ is an alkyl group of C₁ to C₄;

R² and R³ are, independently of each other, a hydrogen atom or an alkyl group of C₁ to C₄; and

n is a number from 25 to 1000.

22. A method according to claim 1, wherein the molar ratio between formaldehyde and dicyandiamide is in the range of from 0.8:

1 to 4;

1.

23. A method according to claim 18, wherein the polyalkylene glycol is a polyethylene glycol.

24. A method according to claim 19, wherein the polyalkoxylated polycarboxylate has the following formula (II):

25. A method according to claim 19, wherein the polyalkoxylated polycarboxylate has an ester level of from 10 to 60%.

26. A method according to claim 20, wherein the ammonium ion of the ammonium derivative has the following formula (IV):

NH(R⁶)₃⁺

where;

the R⁶ groups are identical or different and represent H or an alkyl group of C₁ to C₆.

27. A method according to claim 20, wherein the ammonium derivative is ammonium chloride, ammonium sulphate, ammonium iodide, ammonium bromide, ammonium acetate.

28. A method according to claim 20, wherein the molar ratio between the compound C and the dicyandiamide is from 1 to 1.5.

29. A method according to claim 1, wherein the composition is in the form of an aqueous solution.