WO2014032132A1

WO2014032132A1 - Concentrated sugar additive as set retarder for cement preparations

Info

Publication number: WO2014032132A1
Application number: PCT/BR2012/000324
Authority: WO
Inventors: Helio Haruo USHIJIMA; Silvana MARQUEZ
Original assignee: Cargill Inc
Current assignee: Cargill Inc
Priority date: 2012-08-30
Filing date: 2012-08-30
Publication date: 2014-03-06
Anticipated expiration: 2015-02-28
Also published as: AR092393A1; BR112015004343A2

Description

CONCENTRATED SUGAR ADDITIVE AS SET RETARDER FOR CEMENT

PREPARATIONS

FIELD OF THE INVENTION

The present invention generally concerns a concentrated sugar additive comprising (a) raffinate derived from citric acid recovery industry and (b) a sugar- containing solution useful for delay setting time of cement preparations, such as cement paste, mortar, concrete, etc.

BACKGROUND OF THE INVENTION

- .. Portland cement is mainly composed by clinker, pozzolan and gypsum and acts as an active hydraulic binder that sets when mixed with water by way of a complex series of chemical reactions. The different constituents slowly crystallize and the interlocking of their crystals provides strength. Portland cement not only hardens by reacting with water but also forms a water-resistant final product. For this reason, it has been largely used for building as basic ingredient of cement preparations, e.g. concrete, mortar or cement paste.

Additives have been included in the cement preparations in order to modify the properties of final product and obtain higher quality, low-cost and efficient production .

The setting time of cement preparations is an important property to be adapted. Set retarder additives are useful to delay hydration of cement by forming a film around the cement compounds (e.g., by absorption), thereby preventing or slowing the reaction with water. The thickness of this film will dictate how much the rate of hydration is retarded. After a while, this film breaks down, and normal hydration proceeds.

Gypsum and calcium chloride are used to attempt regulation of setting time of such preparations. Other agents are specifically applied as additives for stopping fresh concrete from quickly drying out, providing reinforced products without cracking. In general, such additives are specific inorganic compounds or complex mixtures (e.g. the additives disclosed in US1859253; US3695906, US5925416, US5573588, WO9940041, and US5993531) .

Thus, there remains a need in the art for alternative environment friendly, low cost additive which effectively act as set retarder for cement preparations.

DESCRIPTION OF THE INVENTION

In order to provide an alternative and environment friendly low cost additive for cement preparations, such as concrete, mortar or cement paste, a specific concentrated sugar additive was developed to be used as set retarder, acting upon plasticity, water retention and adherence.

The additive according to the present invention comprises (a) raffinate and (b) a sugar-containing solution .

According to the present invention the raffinate

(a) is an aqueous solution effluent (for instance syrup or liquor) from fermentation processes (residuary or not) . Raffinate (a) is an aqueous solution comprising at least citric acid, inorganic matter (such as minerals) , proteic matter and sugar matter.

Typically, sugar matter includes carbohydrate selected from fructose, dextrose, maltose and/or polyol selected from arabitol, erythritol, or mixtures thereof. The inorganic matter is measured by analyzing ashes and typically includes nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, iron, manganese, copper, zinc, boron, sodium or mixtures thereof.

In a particular embodiment, raffinate (a) may be a by-product derived from the citric acid recovery process, for instance as disclosed in the patent US 4,994,609, assigned to Cargill Inc. (1991), incorporated herein as reference. The raffinate (a) ingredients ratio depends on the performance of the recovery industry. In this case, a by-product without commercial application is used as raw material to the manufacture of a commercial product, also avoiding cost with waste treatment.

The sugar-containing solution (b) may be obtained from several sources, for instance corn, sugar cane, cassava, potato, wheat, rice, etc. In a particular embodiment such a solution may be syrup, i.e. a viscous liquid with a sugar content. Such a component also includes enzymatic or acid conversion syrup, independently from the conversion grade.

Sugar, according to the present invention, is selected from carbohydrates or saccharides in general, including monosaccharides, disaccharides , oligosaccharides, polysaccharides, or mixture thereof. For instance, the solution (b) comprises monosaccharide such as glucose (dextrose), fructose (levulose), galactose, xylose or ribose; disaccharides such as sucrose, maltose or lactose; oligosaccharides such as raffinose or stachyose; polysaccharides such as or starch, amylose, amylopectin, cellulose, chitin; hydrolysates (for instance inverted sugar), derivatives or mixtures thereof.

According to the present invention the sugar- containing solution (b) may be a viscous concentrated solution of sugar, in water or other liquids (for instance alcohols) . Such a solution may also include other ingredients such as coloring agents, flavors or thickening agents .

In a particular embodiment component (b) contains about 40% equivalent dextrose in relation to about 80% total solids. For instance, such an ingredient is commercialized as Glucogill 40/82 by the Cargill group in Brazil .

The concentrated sugar additive useful as set retarder comprises:

(a) from about 10 to about 90%, preferably about 40% raffinate from a citric acid recovery process, and

(b) from about 10 to about 90%, preferably about 60% glucose syrup.

As a second aspect, the present invention also concerns a process for manufacturing a set retarder comprising the following steps of:

(i) evaporation of raffinate component (a) up to about 65% solids;

(ii) mixing sugar-containing solution (b) until complete homogenization;

The resulting set retarder according to the present invention presents % Brix (sugar parameter) from about 70 to about 75.

The % Brix is analyzed by a refractometer . The viscosity is measured by cooling the sample at 25 °C and 20 rpm in a Brookfield viscometer DV I.

Due to the characteristics of the additive according to the present invention, especially with respect to controlled concentrations of sugar, as well as physical characteristics, it is possible to obtain an improved additive able to delay hydration of cement, i.e. for delay setting time of any kind of cement preparation, such as concrete, mortar, cement paste, etc.

The concentrated sugar additive according to the present invention may also comprise other ingredients well known in the art, such as surfactants, biocides, pH adjusters, thickeners, etc.

The present invention also concerns the use of the additive as described above as set retarder for cement preparations, as well as a method for setting the time of such preparations that comprise applying an acceptable amount of an additive as described above. This method is particularly useful for producing cement preparations having improved characteristics, e.g. plasticity, hardening, non-cracking and non-shrinkage.

The following examples are provided for illustration purposes only, and are not intended as a limitation to the scope of the present invention, other than what is described in the attached claims.

EXAMPLES OBTAINING OF RAFFINATE

A raffinate sample was obtained from the citric acid recovery process disclosed in the patent US 4,994,609, assigned to Cargill Inc. (1991).

Such an ingredient was evaluated in order to identify organic and mineral contents.

One of the tests was carried out to verify the mineral ingredients contained in the raffinate (a) . Therefore, ashes without organic elements (i.e. water, citric acid, raw protein and sugar not converted) were evaluated and the following composition was identified:

Table 1 - Raffinate characteristics: inorganic elements

(<1.0%)

Ingredient Amount

Nitrogen 0.58%

Phosphorus 0.12%

Potassium 35.0 ppm

Calcium 148.0 ppm

Magnesium 25.0 ppm

Sulphur 0.25 ppm

iron 1.0 ppm

iinate characteristics: orga

Ingredient Amount

Citric acid 5%

Fructose 1%

Dextrose 2%

Maltose 4%

Arabitol 0.6%

Erythritol 2.2%

The analyzed sample also contains solids (15%) and trace ingredients (<100ppm) . C/N ratio = 19 and pH = 3.

PREPARATION OF THE SET RETARDER

A sample of the set retarder was prepared by:

(a) evaporation of a raffinate stream according to a process disclosed in the patent US 4,994,609 up to 65% solids ;

(b) mixing 6 kg of the raffinate obtained in the step (a) with 4 kg of a glucose syrup, commercialized as Glucogill 40/82, until complete homogenization.

The sugar content of the resulting mixture was then analyzed: % Brix (sugar parameter) from about 70 to about 75. COMPARATIVE TESTS

Set time

Table 3 - Comparative test (with or without set retarder)

Cement: CP II F 32

Protocol: ABNT NBR NM 65

The result shows that the set retarder according to the present invention presents improved performance when comparing a set time. The set retarder according to the present invention has a 60-minute time to delay the cement set compared to the cement without such a retarder.

Perlimax test

Figure 1 shows that one obtained a better passage of the liquor by perlimax with the amount of 0.01% enzyme in the first and second tests. It was noted that with 0.04%, the passage through perlimax was less effective than the liquor without enzyme. The information contained in the foregoing, as well as in the examples, allows a person skilled in the art to perform alternative embodiments not expressly described, but which perform the functions taught herein with the results revealed herein. Such equivalent embodiments are encompassed by the scope of the invention and are therefore covered by the claims presented further on.

Claims

1. SET RETARDER FOR CEMENT PREPARATIONS comprising a mixture of (a) raffinate and (b) a sugar- containing solution.

2. SET RETARDER, according to claim 1, wherein raffinate (a) is a by-product derived from the citric acid recovery process.

3. SET RETARDER, according to one of claims 1 or 2, wherein raffinate (a) is an aqueous solution comprising at least at., least citric acid, inorganic matter, proteic matter and sugar matter.

4. SET RETARDER, according to claim 3, wherein sugar matter comprises carbohydrate selected from fructose, dextrose, maltose and/or polyol selected from arabitol, erythritol, or mixtures thereof.

5. SET RETARDER, according to claim 3, wherein inorganic matter includes nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, iron, manganese, copper, zinc, boron, sodium, or mixtures thereof.

6. SET RETARDER, according to one of claims 1 to

5, comprising from about 10 to about 90% raffinate.

7. SET RETARDER, according to one of claims 1 to

6, comprising about 40% raffinate.

8. SET RETARDER, according to claim 1, wherein said sugar-containing solution (b) comprises monosaccharide, disaccharide, · oligosaccharide, polysaccharide; or mixture thereof.

9. SET RETARDER, according to one of claims 1 or 8, wherein said sugar-containing solution (b) comprises glucose, fructose, galactose, xylose, ribose, sucrose, maltose, lactose, raffinose, stachyose, starch, amylose, amylopectin, cellulose, chitin, hydrolysates , derivatives or mixtures thereof.

10. SET RETARDER, according to one of claims 1, 8 or 9, wherein said sugar-containing solution (b) is Glucogill 40/82.

11. SET RETARDER, according to one of claims 1 or 8 to 10, comprising from about 10 to about 90% of said sugar-containing solution (b) .

12. SET RETARDER, according to one of claims 1 or 8 to 11, comprising about 60% of said sugar-containing solution (b) .

13. SET RETARDER, according to one of claims 1 or

8 to 12, wherein said sugar-containing solution (b) contains about 40% equivalent dextrose in relation to about 80% total solids.

14. SET RETARDER, according to one of claims 1 or 8 to 13, wherein said sugar-containing solution (b) is derived from corn.

15. SET RETARDER, according to one of claims 1 to 14, presenting %Brix from about 70 to about 75.

16. PROCESS FOR MANUFACTURING THE SET RETARDER according to one of claims 1 to 15 comprising the steps of:

(a) evaporation of raffinate component (a) up to about 65% solids; and

(b) mixing sugar-containing solution (b) until complete homogenization .

17. USE OF THE SET RETARDER according to one of claims 1 to 15 for the control of setting time of cement preparations, such as concrete, mortar or cement paste.

18. METHOD FOR PREPARING CEMENT PREPARATIONS comprising applying an acceptable amount of a set retarder according to one of claims 1 to 15.