EP3461271A1

EP3461271A1 - Admixture

Info

Publication number: EP3461271A1
Application number: EP17712146.4A
Authority: EP
Inventors: Dieter Honert; Thomas Müller; Matthias Dietrich
Original assignee: Sika Technology AG
Current assignee: Sika Technology AG
Priority date: 2016-03-22
Filing date: 2017-03-21
Publication date: 2019-04-03
Also published as: WO2017162698A1

Abstract

The invention relates to an admixture, in particular for activating clinker substitute materials, containing: a) an alkaline earth metal compound, in particular an alkaline calcium compound and b) a water-soluble carbonate.

Description

ADDITIONAL RESOURCES

TECHNICAL FIELD The invention relates to an additive, in particular for activating clinker substitutes and a composition prepared therefrom, in particular a mineral binder composition. Furthermore, the invention relates to methods for grinding mineral solids and uses of an additive as a cement additive in cement production and as a concrete additive.

State of the art

The production of cement generates a considerable amount

climate-relevant CO ₂ . To reduce the CO ₂ emission, can

Cement clinker in the cement production are partly replaced by clinker substitutes.

Cements based on cement clinker, clinker substitutes, and optionally sulfate carriers are referred to as "mixed cements". From

of particular interest in mixed cements is the use of

silicate-containing clinker substitutes, in particular slags, fly ash, silica fume and pozzolans. Such clinker substitutes have latent hydraulic and / or pozzolanic properties.

If a mortar or concrete is produced from mixed cements containing such clinker substitutes, the clinker substitutes react with water and possibly other components to form so-called

Hydrate phases and thus make an amount to harden the

Mixing cement.

However, the hydration of clinker substitutes is slower than that of cement clinker. Therefore, it is the endeavor of appropriate

Activation, the rate of hydration of clinker substitutes too increase. One possibility often described is the acceleration of the hydration of the cement clinker, which in turn causes the hydration of the cement

Clinker substitutes accelerated. However, the full potential of the clinker substitutes can not be exploited with this method.

Another possibility is the direct alkaline activation of the clinker substitutes, usually by NaOH. Here again there are application problems. Pure NaOH, in the form of pellets, powder, or similar. is highly hygroscopic and must be stored under special conditions. In dissolved form, NaOH can only be stored, transported and dosed under special safety precautions. Therefore, this application for cement works hardly in question.

WO 2012/126994 A1 (Sika Technology AG) describes in this

For example, special activator compositions with which, in particular, latent hydraulic and pozzolanic binders can be activated. These are based on compositions containing

Alkali metal or alkaline earth metal hydroxides, metal sulphates, optional

Accelerators and fillers. Concrete compositions contain e.g. Sodium hydroxide, calcium sulfate, calcium nitrate optional and

Calcium carbonate. In another example, calcium hydroxide is used in

Combination with calcium sulfate / sodium sulfate and calcium nitrate used. Although such compositions are quite effective, in certain cases they may adversely affect the level of sulfate carrier, which can lead to solidification defects in binder compositions.

There is therefore still the need for new and improved solutions which overcome the aforementioned disadvantages as possible. Presentation of the invention

The object of the present invention is therefore to provide solutions which use of clinker substitutes in blended cements or facilitate or improve mineral binder compositions. In particular, clinker substitutes should be better activated, so that the potential of clinker substitutes can be used as efficiently as possible in terms of strength development. In particular, the hardening of mineral binder compositions is to be accelerated by the use of clinker substitutes, in particular slags, fly ash, silica fume and natural pozzolans. As far as possible without influencing the content of sulphate carrier in the binder compositions and if possible without special safety precautions during storage, transport or use being necessary. In addition, should

appropriate methods and uses are provided which facilitate the achievement of these goals effectively.

Surprisingly, it has been found that the object according to the invention can be achieved by a composition according to claim 1.

The additive according to the invention, which is particularly suitable for activating clinker substitutes, accordingly comprises: a) an alkaline alkaline earth metal compound, in particular an alkaline calcium compound, and b) a water-soluble carbonate.

As it has been shown, can by the inventive combination of alkaline alkaline earth metal compound, in particular alkaline

Calcium compound, and water-soluble carbonate additives are produced, which effectively activate clinker substitutes

enable. The novel additives can be stored, transported and used without complex safety precautions. Due to the fact that the additives are essentially free of

Sulfates can be produced and used, the content of

Sulfate carrier in binder compositions hardly or not at all influenced. In particular, with the novel additives, the

Hardening of mineral binder compositions in the use of clinker substitutes, especially slags, fly ash, silica fume and natural Pozzolanen be greatly accelerated.

In particular, the compressive strengths of mineral

Binder compositions containing clinker substitutes and the inventive additives, in particular 4 - 8 hours after mixing, be significantly increased.

Furthermore, it is possible with the compositions according to the invention to specifically increase the compressive strengths of mineral binder compositions containing clinker substitutes at early times, in particular after 1 or days, and / or at late times, in particular after 28 days. In particular, both the compressive strengths at early times (1 or 2 days) and the compressive strengths at late times (28 days) can be increased.

In addition, the novel additives with respect to the

Cost / performance ratio extremely interesting. It was further found that the novel additives with respect to unwanted

Ansteifverhalten of mineral binders or mineral

Binder compositions are less problematic. In addition, in the novel additives, if necessary, to potentially problematic substances such as sulfates, NaOH and

the like can be dispensed with. This without any significant loss of effect. Further aspects of the invention are the subject of further independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims. Ways to carry out the invention

In a first aspect, the invention relates to an additive which is particularly suitable for the activation of clinker substitutes and includes the following components: a) an alkaline alkaline earth metal compound, in particular an alkaline calcium compound, and b) a water-soluble carbonate. In a preferred embodiment, the additive consists of the two components mentioned.

Under an "alkaline earth alkali metal compound" is present in a

Understanding substance that contains alkaline earth metals or alkaline earth metals and is able to increase the pH of an aqueous solution or to form hydroxide ions. In other words, the alkaline earth alkaline metal compound is a basic one

Alkaline earth metal. The alkaline earth alkaline metal compound can also be mixtures of

contain different alkaline earth metals and / or there may be several different alkaline earth alkali metal compounds.

In particular, the alkaline earth metal compound is an alkaline earth metal oxide. When using alkaline earth metal oxides, a particularly effective activation of clinker substitutes can be achieved.

Preferably, the alkaline alkaline earth metal compound contains as alkaline earth metals calcium and / or magnesium, more preferably calcium. In these cases, the alkaline earth alkaline metal compound is an alkaline calcium compound and / or an alkaline magnesium compound. There may also be mixtures of an alkaline calcium compound and an alkaline magnesium compound.

More preferably, the alkaline earth alkaline metal compound comprises or consists of an alkaline calcium compound.

In particular, the alkaline calcium compound comprises at least one member selected from the group consisting of calcium oxide, calcium hydroxide, calcium acetate, calcium dihydrogen phosphate, calcium propionate and

Calcium formate or mixtures thereof. In particular, it is calcium oxide and / or calcium hydroxide. Especially advantageous is calcium oxide or CaO.

If present, an alkaline magnesium compound in the

Specifically, at least one member selected from the group consisting of magnesium oxide, magnesium hydroxide, magnesium acetate,

Magnesium dihydrogen phosphate, magnesium propionate and magnesium formate or mixtures thereof. In particular, it is magnesium oxide and / or magnesium hydroxide. Especially advantageous is magnesium oxide or MgO.

Especially preferred as alkaline alkaline earth metal compounds are demanch calcium oxide and / or magnesium oxide. The said calcium compound or magnesium compounds can also be present as mixed forms which contain both calcium and magnesium atoms. An example of such a hybrid is

Calcium magnesium acetate. Other mixed forms can be derived analogously. The alkaline alkaline earth metal compound, in particular the alkaline calcium compound, in particular calcium oxide, very particularly preferably has a specific surface area of 1 to 50 m ² / g, preferably 1 to 5 to 30 m ² / g, in particular 1 to 9 to 10 m ² / g on. The determination of the specific Surface is carried out in particular by the BET method (N ₂ adsorption, measured according to DIN ISO 9277: 2003-05). A high specific surface leads to an improvement of the activation effect. In order to achieve the same effect, proportionally less alkaline can be obtained compared with alkaline earth alkaline alkaline compounds having a low specific surface area

Alkaline earth metal compound can be used with high specific surface area.

The term "carbonate" in the present case salts and / or esters of

Carbonic acid (H2CO3) meant. In particular, they are salts. From the two-prote (dibasic) carbonic acid, two series of salts are derived: (i) the hydrogencarbonates, which are also called primary carbonates (MHCO3, based on the hydrogencarbonate anion HCO3 ^" ) and (ii) the secondary carbonates (M2CO3 based on the carbonate anion CO ₃ ^{2 "} ). "M" stands for a metal ion, an ammonium group which may optionally be substituted, or a mixture thereof. Different metal ions or metal ions and ammonium groups may be mixed. The ammonium group is in particular a group of the formula NH ₄ ⁺ . However, substituted ammonium groups such as alkyl and / or

Alkanol groups carrying ammonium groups, in particular with 1-10

Carbon atoms present. Corresponding to carbonates and / or Hyxrogencarbonate be used with deratigen ammonium groups. For example in the form of ethanol-ammonium carbonate and / or triethanolammonium hydrogencarbonate.

In the present context, secondary carbonates (M ₂ CO ₃ ) have been found to be preferred. Accordingly, the water-soluble carbonate is preferably a secondary carbonate or a compound of the formula M2CO3. A "water-soluble carbonate" in the present context stands for a carbonate which has a solubility of at least 10 g / l of water at 20 ° C. and a pressure of 101 .325 Pa. The solubility of the water-soluble carbonate in water is thus in the

Especially greater than the solubility of calcium carbonate in water.

The latter has a solubility of only 14 mg / l in water at 20 ° C.

The solubility of the water-soluble carbonate is preferably at least equal to 33 g / l of water, more preferably at least 100 g / l of water, more preferably at least 150 g / l of water, most preferably at least 200 g / l of water, in particular at least 300 g / l of water or at least equal to 500 g / l of water. The water-soluble carbonate advantageously comprises at least one member selected from the group consisting of alkali metal carbonates,

Alkali hydrogencarbonates, ammonium carbonates,

Ammonium hydrogencarbonates or mixtures thereof. The

Ammonium group is in particular a group of the formula NH ⁺ . In a further possible embodiment, the

Ammonium groups to substituted ammonium groups, in particular as described above. In particular, the water-soluble carbonate comprises an alkali metal or is in the form of an alkali metal carbonate. More preferably, the alkali metal is sodium and / or potassium.

In particular, the at least one water-soluble carbonate comprises sodium carbonate (Na ₂ CO ₃ ) and / or potassium carbonate (K ₂ CO ₃ ). Very particular preference is given to sodium carbonate (Na ₂ CO ₃ ).

The alkaline alkaline earth metal compound, especially the alkaline one

Calcium compound, and the water-soluble carbonate are particularly selected so that, if added to an aqueous medium, in a Temperature of 20 ° C in an exothermic reaction form calcium carbonate (CaCOs).

In a particularly preferred embodiment, the additive contains a combination of an alkali metal carbonate and a mineral and / or inorganic calcium compound. Especially preferred are sodium carbonate and calcium oxide.

A molar ratio of the alkaline alkaline earth metal compound, in particular the alkaline calcium compound, to the water-soluble carbonate, based on the Erdalkaliatome, in particular calcium atoms, in the alkaline

Alkaline earth metal compound and based on the carbonate groups in

water-soluble carbonate, is advantageously in the range of 1: 2 - 2: 1,

in particular 1: 1 .5- 1 .5: 1, preferably 1: 1 .25 - 1 .25: 1, especially 1: 1 .1 - 1 .1: 1, particularly preferably 1: 1.

Specifically preferred are the following combinations of alkaline earth alkaline metal compounds and water soluble carbonates: a) an alkaline earth metal oxide in combination with a secondary carbonate; b) An alkaline calcium compound and / or an alkaline

Magnesium compound in combination with a secondary carbonate; c) calcium oxide and / or magnesium oxide in combination with a

secondary carbonate; d) calcium oxide and / or magnesium oxide in combination with sodium carbonate and / or potassium carbonate; e) calcium oxide in combination with sodium carbonate; f) calcium oxide in combination with potassium carbonate; g) magnesium oxide in combination with sodium carbonate; h) magnesium oxide in combination with potassium carbonate; In this case, the abovementioned molar ratios are advantageously realized.

The alkaline alkaline earth metal compound, which is in particular an alkaline calcium compound, and / or the water-soluble carbonate are advantageously present as a solid, in particular as a free-flowing solid. The solid may e.g. as powders, flakes, tablets, pellets and / or blocks. Most preferably, the additive is as a whole as a solid,

especially free-flowing solid, before. Particular preference is given to powders, flakes, tablets, pellets and / or blocks. Especially preferred are powders in each case.

If the alkaline alkaline earth metal compound, in particular the alkaline calcium compound and / or the water-soluble carbonate are present as a powder, an average particle size is in particular 0.01-100 μιτι, preferably 0.1-100 μιτι, special 1-50 μιτι. The particle size, their distribution or the average particle size can

in particular by laser diffraction, preferably in accordance with ISO standard

13320: 2009, to be determined. In particular, this is a device

Mastersizer 2000 with a dispersing unit Hydro 2000G and the software Mastersizer 2000 from Malvern Instruments GmbH (Germany) used. As measuring medium, e.g. Isopropanol suitable. The

average particle size here corresponds in particular to the D50 value (50% of the particles are smaller than the specified value, 50%

correspondingly larger).

A content of water in the additive, based on the total weight of the additive, is in particular less than 5 wt .-%, in particular less than 2 wt .-%, preferably less than 1 wt .-%, especially less than 0.5 wt .-% or less than 0.1% by weight. This is especially preferred

Additive essentially or completely anhydrous.

Based on the total weight of the additive, in a particular embodiment this contains less than 5% by weight, in particular less than 2 wt .-%, preferably less than 1 wt .-%, in particular less than 0.1 wt .-% alkali metal hydroxides, in particular NaOH and / or KOH.

Preferably, the additive contains, based on the total weight of the additive, less than 5 wt .-%, in particular less than 2 wt .-%, preferably less than 1 wt .-%, in particular less than 0.1 wt .-%, alkaline earth metal carbonates, in particular calcium carbonate (CaCO ₃ ). Particularly preferably, the additive is substantially free of such substances. These are in particular alkaline earth metal carbonates in solid form.

Advantageously, the additive contains, based on the total weight of the additive, less than 5 wt .-%, in particular less than 2 wt .-%, preferably less than 1 wt .-%, in particular less than 0.1 wt .-%, metal sulfates, especially calcium sulphate, in particular calcium sulfate

Hemihydrate or CaSO ₄ · 0.5 H ₂ O. the additive is substantially free of such substances particularly preferred.

In particular, the additive contains, based on the total weight of the additive, less than 5% by weight, in particular less than 2% by weight, preferably less than 1% by weight, in particular less than 0.1% by weight, of hydraulic Binders, in particular cement, in particular

Portland cement. Particularly preferably, the additive is substantially free of such substances.

A proportion of the alkaline earth alkaline metal compound, especially the alkaline calcium compound, and the water-soluble carbonate

in particular at least 50 wt .-%, preferably at least 75 wt .-%, in particular at least 90 wt .-%, in particular at least 95 wt .-% or 100 wt .-% together.

In a particularly preferred embodiment, the additive comprises: a) 10-90% by weight, in particular 25-75% by weight, preferably 30-50% by weight, of the alkaline earth-alkaline metal compound, in particular the alkaline calcium compound; b) 10-90% by weight, in particular 25-75% by weight, preferably 55-70% by weight, of the water-soluble carbonate, in each case based on the total weight of the additive.

Especially preferably, the admixture contains 30-40% by weight, in particular 34-36% by weight, calcium oxide and 60-70% by weight, 64-67% by weight.

Sodium.

According to a further advantageous embodiment, the

Inventive additive used together with at least one retarder or it contains this. In principle, a multiplicity of substances known to the person skilled in the art can be used here. However, the at least one retarder particularly advantageously comprises at least one hydroxycarboxylic acid and / or at least one carbohydrate. Hydroxycarboxylic acids are particularly advantageous. Preferably, the retarder is selected from the group comprising

Tartaric acid, citric acid, lactic acid, fructose, sucrose, glucose, lactose, mannose, ribose, galactose, fucose, rhamonose, lactulose, maltose, trehalose, melezitose, raffinose, molasses, caramel and

Umbelliferose or mixtures thereof. Particularly preferred are tartaric acid and / or citric acid.

As has been shown, the inventive additives are generally well compatible with such retarders. This allows, for example, a flexible adaptation to special uses.

In particular, a weight ratio of the at least one retarder to the alkaline alkaline earth metal compound, in particular the alkaline Calcium compound, in the range of 100: 1 - 1: 100, preferably 50: 1 - 1: 50, in particular 10: 1-1: 10 or 2: 1 - 1: 2.

Based on the binder content, the at least one retarder is preferably used in a proportion of 0.001-10 wt.%, In particular 0.01-5 wt.%, Especially 0.1-2 wt.%, In particular 0.5-1 wt. -%, used.

It may also be advantageous if the additive according to the invention is used in combination with a concrete additive and / or a mortar additive, and / or process chemicals. These include in particular a defoamer, a dye, a preservative, a flow agent, an air entraining agent, a Schwindreduzierer and / or a

Corrosion inhibitor or combinations thereof.

The inventive additive can be used as a carrier for the

Concrete additives and / or mortar additives act. This is particularly interesting if it is the concrete admixtures and / or

Mortar additives to substances, which due to their

Physicochemical properties are not usable in aqueous form. Specifically, these are, for example, highly hygroscopic, storage-unstable or sparingly soluble in water substances. With respect to known support, e.g. from inert carrier materials, are available are the places

according to the invention additives themselves active additives.

If the additive according to the invention is added to a mineral solid which can be activated by the additive, e.g.

Blast furnace slag, the mineral solid, in particular

Blast furnace slag used as a reactive carrier material for other concrete admixtures and / or mortar admixtures.

Advantageously, the inventive additive is used together with a flow agent or condenser or it contains such. When Examples of suitable flow agents are lignosulfonates, sulfonated naphthalene-formaldehyde condensates, sulfonated melamine-formaldehyde condensates, sulfonated vinyl copolymers, polycarboxylates or mixtures thereof.

The flow agent specifically includes a polycarboxylate, especially a polycarboxylate ether. In particular, the flow agent is a comb polymer comprising a polycarboxylate backbone attached thereto

Chain polyether sides. The side chains are bonded to the polycarboxylate backbone, in particular via ester, ether, imide and / or amide groups.

Advantageous flow agents are e.g. Copolymers of (meth) acrylic acid and / or maleic acid monomers and monomers selected from polyalkylene glycol vinyl ethers, polyalkylene glycol (meth) allyl ethers, or polyalkylene glycol isoprenyl ethers. Particularly suitable are e.g. Copolymers of maleic acid or derivatives thereof, allyl ethers, especially allyl-polyethylene glycols, and vinyl acetate. Corresponding copolymers and their preparation are described, for example, in EP 2 468 696 A1 (Sika Technology AG). Particularly suitable are e.g. are the copolymers P-1 to P-4 as described in paragraphs 0058 to 0061 and Table 1 of EP 2 468 696 A1.

Also suitable are, for example, copolymers of maleic acid or derivatives thereof, allyl ethers, in particular allyl polyethylene glycols, and (meth) acrylic acid. Such copolymers and their preparation are described in EP 2 522 680 A1 (Sika Technology AG). For example, the copolymers P-1 to P-4 as described in paragraphs 0063 to 0070 and table 1 of EP 2 522 680 A1 are advantageous. Furthermore, suitable polycarboxylate ethers and production processes are disclosed, for example, in EP 1 138 697 B1 on page 7 line 20 to page 8 line 50, and in its examples or in EP 1 061 089 B1 on page 4, line 54 to page 5 line 38 and in their examples. In a variety of it, as described in EP 1 348 729 A1 on page 3 to page 5 and in their examples, the comb polymer can be prepared in a solid state of aggregation. The disclosures of the patents mentioned in connection with the flow agents are hereby incorporated by reference in particular.

Corresponding comb polymers are also sold commercially by Sika Schweiz AG under the trade name series ViscoCrete®.

In particular, a weight ratio of the at least one flow agent to the alkaline alkaline earth metal compound, in particular the alkaline calcium compound, is in the range from 100: 1-1: 100, preferably 50: 1-1: 50, in particular 10: 1-1: 10 or 2: 1. 1: 2.

Based on the binder content, the flow agent is preferably used in a proportion of 0.001-10 wt%, in particular 0.01-5 wt%, especially 0.1-2 wt%, in particular 0.5-1 wt%. used. Thus, good liquefaction effects can be achieved with effective activation of clinker substitutes at the same time. The solvent affects the effect of the additive barely or not at all.

The additive according to the invention can basically be present in a wide variety of forms. In particular, the individual components of the

Additive as individual components spatially next to each other, especially as a so-called "kit of parts". But it is also possible to premix one or all components of the additive in solid and / or liquid form.

Particularly preferably, the additive is present as a one-component additive. Advantageously, all components of the additive in solid Form, in particular in free-flowing form, especially preferably in powder form, mixed before.

In a further aspect, the present invention relates to a

Composition, in particular a binder composition containing an additive as described above and a mineral solid.

The composition may e.g. in dry or liquid form or as a fluid or starched with mixing water

Binder composition are present. Also, the composition may be used as a cured binder composition, e.g. as a shaped body. In the present context, a "mineral solid" is in particular an inorganic solid The solid may in principle be present in coarse form, for example as (unground) clinker, and / or already partly ground, in particular a silicate-containing mineral solid in that the mineral solids contain or consist of silicates.

Preferably, the solid is an inorganic substance for construction,

For example, a component of cement, mortar and / or

Concrete compositions. Preferably, the solid is a mineral binder, an additive for a mineral binder and / or

Aggregate.

A "mineral binder" is in particular a binder, in particular an inorganic binder, which reacts in the presence of water in a hydration reaction to solid hydrates or hydrate phases. This can be, for example, a hydraulic binder (eg cement or hydraulic lime), a latent hydraulic binder (eg slag or granulated slag), a pozzolanic binder (eg fly ash, trass or Rice husk ash) and / or a non-hydraulic binder (gypsum or white lime). It is also possible to mix the various binders. A "mineral binder composition" is accordingly a composition containing at least one mineral binder.

The mineral solid comprises in particular a cement clinker, a clinker substitute, sand and / or mixtures thereof. Particularly preferred is a cement clinker, a clinker substitute, and / or mixtures thereof. Particularly preferred is a clinker substitute.

The mineral solid contains, based on the total weight of the mineral solid, in particular at least 5 wt .-%, preferably at least 10 wt .-%, in particular at least 30 wt .-%, in particular at least 50 wt .-%, more preferably at least 60 wt % or at least 80% by weight of a clinker substitute. In particular, is the

Proportion of the clinker substitute at least 95% by weight, at least 99% by weight or 100% by weight. In particular, the mineral solid is made up of unavoidable impurities exclusively from a clinker substitute. Bes

The cement clinker is in particular a Portland cement clinker or a

Cement clinker type CEM I according to EN 197-1: 2014-07.

In the present case, "clinker substitutes" are understood in particular to be substances of type I and type II in accordance with standards DIN EN 206-1: 2014-07 and DIN 1045-2: 2014-08.

The mineral solid or the clinker substitutes preferably comprise pozzolanic and / or latent hydraulic additives. These can also be referred to as additives of type II according to standards DIN EN 206-1: 2014-07 and DIN 1045-2: 2014-08. In a particular embodiment, the mineral solid consists exclusively of pozzolanic and / or latent hydraulic additives. Particularly preferred as clinker substitutes are blast furnace slag,

Blastfurnace slag, silica fume, fly ash and / or pozzolans. In particular, it is blast furnace slag.

A proportion of the additive based on the mineral solid, in particular the clinker substitute, is advantageously in the range from 0.1 to 40% by weight, preferably 1 to 30% by weight, in particular 2 to 20% by weight, especially preferably 3 - 15 wt .-%, most preferably 5 - 10 wt .-%.

The present invention also relates to a method, in particular for producing a mineral binder composition, wherein an additive according to the invention is mixed with a mineral solid. In particular, the additive becomes a mineral

Binders and / or aggregates added. A mineral

Binder composition is in particular a concrete and / or

Mortar composition. Aggregates are to be understood in particular as sand, gravel and / or aggregates.

The individual components of the additive can be added separately or together with the mineral solid.

When a mineral binder composition is prepared, the addition of the additive may occur before, during and / or after the addition of the make-up water. In a preferred embodiment, the addition of the additive takes place before the addition of the mixing water. An additional aspect of the present invention relates to a molded article which is obtainable by curing a composition as described above comprising at least one mineral binder and an additive according to the invention after addition of

Water. The molded body produced in this way can be virtually any desired Form and, for example, be part of a building, such as a building, a masonry or a bridge.

Another aspect of the present invention relates to a method for grinding mineral solids, in particular cement clinker and / or clinker substitutes, wherein an additive as described above with a mineral solid, in particular a

silicate-containing mineral solid, preferably cement clinker,

Klinkerersatzstoffen and / or sand is ground. The substances mentioned are defined as described above.

The term "milling" or "grinding process" is in particular a

Process understood in which an average grain size of a solid or a mixture of different solids is reduced. This is done, for example, in a mill. As a mill, e.g. a

Mahlkörpermühle, in particular a ball mill can be used. In grinding media millbases and freely moving media are circulated in a process chamber. This results in shocks between the grinding media, the walls of the process chamber and the regrind. The comminution of the ground material takes place in particular by fragmentation and not by a rollover process. Also possible is the grinding in a roller mill. A "roller mill" is a mill in which at least one milling tool is arranged on a substantially horizontally rotatable grinding plate or grinding bowl unrollable. The term "roller mill" in the present case also includes "roller mills", "vertical mills" and "vertical roller mills".

Typically, the mineral solid, in particular cement clinker and / or clinker substitutes, when grinding to a Blaine value of at least 500 cm ² / g, in particular at least 1 Ό00 cm ² / g, preferably at least 2Ό00 cm ² / g, more preferably at least 2 '500 cm ² / g, ground. In particular, the mineral solid comprises during grinding

Includes or consists of clinker substitutes. Blast furnace slag, blastfurnace slag, silica fume, fly ash and / or pozzolans, in particular blast furnace slag, are particularly preferred.

In a particular embodiment, moist clinker substitutes are ground with an additive according to the invention. The wet ones

Clinker substitutes contain, based on the total weight of the moist clinker substitutes, in particular 0.1 to 20 wt .-%, especially 1 to 15 wt .-%, in particular 5 to 12 wt .-% or 10 wt .-%, moisture in the form of Water. The moisture can be known to those skilled in the art

For example, be determined gravimetrically

As it has been shown, with the additive added according to the invention, the existing residual moisture can be largely removed. This due to the reaction of the alkaline earth alkaline metal compound,

in particular the alkaline calcium compound, with the water-soluble carbonate in the humid environment. For example, calcium oxide reacts with sodium carbonate in the presence of water to calcium carbonate and

Sodium hydroxide. Water is eliminated in this process, while the products (calcium carbonate and sodium hydroxide) accumulate in dry form on the surface of the clinker substitutes and are available, for example, for the later activation of the clinker substitutes. Accordingly, with the additive according to the invention or the process carried out with it, additional measures for drying the clinker substitutes, which are usually in moist form, can be dispensed with, or the drying effort can be at least greatly reduced. This saves energy and time in particular.

In addition, the additive according to the invention can act as a grinding aid during the grinding process. In this case, additives can facilitate the comminution of mineral solids in the mills and / or the To prevent agglomeration of the resulting pul deformed particles. This can cause a large reduction in the grinding time and the energy required for grinding. According to a particularly preferred method, clinker substitutes are ground in a first step with an additive according to the invention and in a subsequent second step with a

Cement clinker and / or ground cement mixed. In the first step, there is advantageously no cement clinker present. As a result, different mixed cements can be produced in a flexible manner, which contain additives according to the invention adapted to the contained clinker substitutes in a suitable amount. These methods are characterized by a high degree of flexibility. In another advantageous method, clinker substitutes and cement clinker are ground together with an additive according to the invention. In this case, can be in a single grinding process

Produce mixed cements. The process is therefore particularly fast and efficient.

Furthermore, the present invention relates to various uses of the inventive additive.

In particular, the additive can be used as a cement additive in cement production.

It is also possible, the inventive additive as a concrete and / or mortar additive in the production of a mineral

Binder composition, in particular a concrete and / or

Mortar composition, to use.

The admixture can be used in particular for the activation of

Use clinker substitutes, especially for the activation of latent hydraulic and / or pozzolanic additives. Particularly preferred are blast furnace slags, fly ash, silica fume and / or pozzolans, in particular blast furnace slags. Furthermore, the additive can be used to increase the compressive strength of mineral binder compositions.

In particular, the additive is used to increase the compressive strength after 6 hours, 1 day, 2 days and / or 28 days. Most preferably, the additive is used to increase the compressive strength after 6 hours, 1 day, 2 days and 28 days at the same time.

Also possible is the use of the inventive additive for the activation of silica and / or sand. Such activated sand can be used, for example, as a clinker substitute or as a cement substitute (SCM;

"supplementary / cementitious material"). The activation is based in particular on an alkali-aggregate reaction.

Furthermore, the additive according to the invention can be used for drying clinker substitutes.

Also possible is the use of the additive according to the invention as a grinding aid in the grinding of mineral solids,

in particular of silicate-containing mineral solids, preferably of cement clinker, clinker substitutes and / or sand.

Also possible is the use of the inventive additive as a carrier material for other concrete admixtures and / or mortar additives.

The following embodiments further illustrate the invention.

embodiments

Test series A Additional medium:

An additive Z consisting of 34.6% by weight of powdered calcium oxide (CaO) and 65.4% by weight of powdered sodium carbonate (Na 2 CO 3) was prepared. The substances are available from various suppliers in pure form (purity> 97%).

grinding:

The additive Z was then used in a conventional ball mill with a proportion of 8 wt .-% in the grinding of wet blast furnace slag and ground to a fineness Blaine of about 3'500 cm ² / g. Additional measures for drying were not required. The blast furnace slag thus obtained is hereinafter referred to as H1.

Further, another batch of wet blast furnace slag under similar conditions on the same mill but without the addition of the

Additive Z also ground to a Blaine fineness of about 3,500 cm ² / g. Here, measures had to be taken to dry. The blast furnace slag thus obtained is hereinafter referred to as H2

Production of mixed cements:

The blast furnace slag H1 was mixed with already ground Portland cement (type CEM I) to form a mixed cement M1. The proportion of cement was 60 wt .-% and the proportion of blast furnace slag H1 40 wt .-%.

An analogous mixed cement M2 was prepared using blast furnace slag H2. Mortar compositions:

With the mixed cements M1 and M2, sand (maximum particle size 8 mm), polycarboxylate flow agents and water-processable mortar mixtures (MM1, MM2) were mixed in with equal proportions.

In a further experiment, a mortar mixture MM3 was prepared essentially analogously to the mortar mixture MM2. Before the addition of the

However, mixing water Z was admixed with additive Z (8% by weight, based on the content of slag in the mortar mixture).

The following list gives an overview of the mortar compositions:

No mixed cement remarks

Mill MM1 M1 slag with additive Z

MM2 M2 no additive Z available

MM3 M2 addition of additive Z when applying

Mortar Tests: In order to investigate the effect of the additive Z in the mortar compositions, the compressive strengths of the mortar mixtures were determined in each case 6 hours after mixing the mortar mixtures. The exam The compressive strength (in N / mm ² ) was determined on prisms (40 x 40 x 160 mm) in accordance with the standards EN 12390-1 to 12390-4.

It has been found that the compressive strength of the mortar mixture MM1 and MM3 (containing additive Z) is significantly higher than that of mortar mixture MM2 (without additive Z).

Series B For Series B, various admixtures based on different alkaline earth metal compounds and different carbonates were prepared. The respective compositions (Z10 - Z15, Z20 - Z27 and Z30 - Z34) are shown in the following tables, wherein the additives each consisted of equimolar amounts of the water-soluble carbonate and the alkaline alkaline earth metal compound. For comparison purposes, experiments without additives (Experiments No. R1, R2 and R4) and experiments with NaOH instead of an inventive mixture of carbonate and alkaline earth metal compound were tested (experiment no. R3).

The effect of the additives was in slag-based mortar mixtures consisting of 900 g of slag and 2700 g of sand (standard sand),

Additive and water (w / c = 0.5) tested. The additives were used in a proportion of 10% by weight, based on the weight of the slag

used.

Then, the compressive strengths of the mortar blends were each 1 day (1 day), 2 days (2 days) and 28 days (28 days) after dressing

Mortar mixtures determined. The test for determining the compressive strength (in N / mm ² ) was carried out on prisms (40 x 40 x 160 mm) in accordance with the standards EN 12390-1 to 12390-4. The slump (ABM) of the slag-based mortar mixtures was measured according to standard EN 1015-3 immediately after mixing.

Table 1

All of the additive compositions tested in Table 1 exhibit significant increases in strength over the reference at least at one of the test times after 1d, 2d or 28d. The compositions Z10 (Na ₂ CO 3 and CaO) as well as Z 12 (K 2 CO 3 and CaO) cut off particularly well, which increase the strengths especially strongly at all times.

Table 2

No. Carbonate Alkaline earth metalM ADMIVI Pressure resistance [MPa] bond [mm] 1d 2d 28d

R2 - - 231 0.4 1 .3 18.3

R3 NaOH (for comparison) 21 1 4.1 6.4 13.1

Z20 Na ₂ CO ₃ CaO 177 8.7 12.6 24.8

Z21 Na ₂ CO ₃ Ca (OH) ₂ 120 9.6 1 1 .1 18.4

Z22 Na ₂ CO ₃ MgO 198 6.9 15.3 34.8

Z23 Na ₂ CO ₃ Mg (OH) ₂ 21 1 0.5 4.4 29.1

Z24 Na ₂ CO ₃ CaHPO ₄ 199 0.5 4.6 33.5

Z25 Na ₂ CO ₃ Ca formate 231 - 0.3 28.2

Z26 Na ₂ CO ₃ Ca acetate 231 - - 24.3 Z27 Na ₂ CO ₃ Ca-propionate 253 - - 19.4

It is noteworthy in relation to the experiments in Table 2, among other things, that with the mixtures according to the invention at late times (28d) better values can be achieved in each case than with the problematic NaOH (experiment R3). Also, the compositions of the present invention are somewhat surprising in terms of strength at earlier times (see, for example, experiment Z20-Z22). Particularly noteworthy are in particular the experiments Z20 (Na ₂ CO ₃ with CaO) and Z22 (Na ₂ CO ₃ with MgO), which cause a remarkable increase in strength both at early times and at late times.

Table 3

Significant increases in strength were also observed with the compositions presented in Table 3. Particularly advantageous are the compositions Z30 (Na ₂ CO ₃ and MgO) and Z32 (K ₂ CO ₃ and MgO), which particularly increase the strengths at all times. Especially good is composition Z32 (K ₂ CO ₃ and MgO). The present experiments prove that with inventive

Compositions significant increases in strength in mortar compositions containing clinker substitutes can be achieved. Depending on

Composition can specifically increase the strengths too early (especially after 1 d, 2 d), later times (28 d) or at all times (1 d to 28 d) become. In addition, the compositions perform better than

conventional activating agents such as e.g. NaOH, which, as explained above, are also unfavorable for many applications for process-related reasons.

However, the embodiments described above are to be understood merely as illustrative examples, which may be modified as desired within the scope of the invention. In particular, other than those mentioned herein may be water-soluble

Carbonates and / or alkaline alkaline earth metal compounds are used.

For example, in the experiments shown in Table 1, other carbonates may also be used, e.g. Propylene carbonate and / or

Ammonium carbonate [(NH ₄₎ ₂ CO _3] and / or ammonium

[(NH) HCO3]. Accordingly, the additive can then consist of propylene carbonate and CaO, ammonium carbonate and CaO and / or ammonium bicarbonate and CaO.

Likewise, in the experiments shown in Table 2, but also in all other experiments, the alkaline earth metal compounds, for example

exchanged or supplemented by other representatives of these

Substance classes. For example, as the alkaline earth metal compound

Magnesium acetate can be used. Accordingly, an additive in this case consists, for example, of magnesium acetate and Na ₂ CO ₃ .

In addition, instead of the mentioned slag mortar and mortar can be used, which in addition to or instead of slag other

Clinker substitutes and / or binders, e.g. hydraulic binders, especially cement.

Claims

Zusatzm ittel, in particular for the activation of clinker substitutes, containing: a) an alkaline alkaline earth metal compound, in particular a

alkaline calcium compound, and b) a water-soluble carbonate.

Additive according to claim 1, characterized in that the alkaline alkaline earth metal compound and the water-soluble carbonate are present as a solid, in particular as a powder.

Additive according to at least one of the preceding claims, wherein the alkaline earth alkaline metal compound is an alkaline

Calcium compound comprising at least one member selected from the group consisting of calcium oxide, calcium hydroxide, calcium acetate, calcium dihydrogen phosphate, calcium propionate and calcium formate or mixtures thereof.

Additive according to at least one of the preceding claims, wherein the water-soluble carbonate comprises at least one member selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, ammonium carbonates, ammonium bicarbonates or mixtures thereof.

An additive according to at least one of the preceding claims, wherein the water-soluble carbonate comprises sodium carbonate (Na ₂ CO ₃ ) and / or potassium carbonate (K ₂ CO ₃ ), preferably sodium carbonate (Na ₂ CO ₃ ).

The additive of at least one of the preceding claims wherein the alkaline earth alkaline metal compound comprises calcium oxide and the water soluble carbonate comprises sodium carbonate (Na ₂ CO ₃ ).

7. Additive according to at least one of the preceding claims, wherein a molar ratio of the alkaline alkaline earth metal compound, in particular the alkaline calcium compound, to the water-soluble carbonate, based on the Erdalkaliatome, in particular based on the calcium atoms in the alkaline earth alkali metal compound and based on the carbonate groups in the water-soluble carbonate, in the range from 1: 2 to 2: 1, in particular 1: 1 to 5: 1: 5: 1, preferably 1: 1: 25 to 1: 25: 1, especially 1: 1: 1 to 1: 1: 1, particularly preferably 1: 1.

8. Additive according to at least one of the preceding claims, containing, based on the total weight of the additive, less than 5 wt .-%, in particular less than 2 wt .-%, preferably less than 1 wt .-%, in particular less than 0.1 % By weight, metal sulphates, especially calcium sulphate, in particular calcium sulphate hemihydrate or CaSO ₄ .0.5 H ₂ O. 9. Additive according to at least one of the preceding claims

comprising: a) 10-90% by weight, in particular 25-75% by weight, preferably 35-65% by weight, of the alkaline earth-alkaline metal compound, in particular the alkaline calcium compound; b) 10-90% by weight, in particular 25-75% by weight, preferably 35-65

Wt .-%, de water-soluble carbonate, each based on the total weight of the additive.

10. Additive according to at least one of the preceding claims, additionally containing a retarder, preferably at least one hydroxycarboxylic acid and / or at least one carbohydrate.

1 1 composition, in particular a binder composition containing an additive according to at least one of the preceding claims and a mineral solid, in particular a silicate-containing mineral solid, preferably cement clinker,

Clinker substitutes and / or sand.

12. The composition of claim 1 1, wherein a proportion of the additive based on the mineral solid, in particular the

Clinker substitute, in the range of 0.1 to 40 wt.%, Preferably 1 to 30 wt.%, In particular 2 to 20 wt.%, More preferably 3 to 15 wt.%, Very particularly preferably 5 to 10 wt. -%, lies.

13. A method for grinding mineral solids, in particular cement clinker and / or clinker substitutes, characterized in that an additive according to one of claims 1 - 10 with a mineral solid, in particular a silicate-containing mineral solid, preferably cement clinker, clinker substitutes and / or sand is ground ,

14. Use of an additive according to any one of claims 1 - 10 as a cement additive in cement production and / or as a concrete and / or mortar additive in the production of a mineral binder composition, in particular a concrete and / or mortar composition.

15. Use of an additive according to any one of claims 1 - 10 for the activation of clinker substitutes and / or for the drying of

Clinker substitutes.