WO2011044604A1

WO2011044604A1 - Mineral foam

Info

Publication number: WO2011044604A1
Application number: PCT/AT2010/000387
Authority: WO
Inventors: Falco Ducia
Original assignee: Geolyth Mineral Technologie Gmbh
Priority date: 2009-10-15
Filing date: 2010-10-13
Publication date: 2011-04-21
Also published as: EP2488466A1; AT509011B1; AT509011A1

Abstract

The invention relates to a formulation for producing a self-hardening mineral foam, comprising a hydraulically setting binder, a pozzolanically setting binder, and a sulfate, wherein the hydraulically setting binder is formed by a sulfate-aluminate cement, comprising a sulfate component and an aluminum component, and is contained in a proportion of at least 50 weight percent.

Description

mineral foam

The invention relates to a formulation for the production of a self-hardening mineral aggregate comprising a hydraulically setting binder and a pozzolanic setting binder and a sulfate, a mineral foam having pores comprising a hydraulically setting component and a foam component, a component having a component body, a process for the production a self-hardening mineral foam according to the pulverulent constituents for the preparation of preceding formulation are mixed together in a mixer in a mixture to a mixture and this mixture water for

Forming of a slurry is added, and an apparatus for producing a self-curing mineral foam comprising a first mixing section for producing a slurry of powdered components and water. Mineral foams are already known from the prior art. Thus, for example, EP 0 628 523 A1 discloses a process for producing a thermal insulation material made of quartz powder having a BET specific surface area of at least about 3 m ² / g, hydrated lime, water, foam and a rapid cement containing reactive aluminates, in which the Thermal insulation material has a density of less than 250 kg / m ³ . From the raw materials, a pourable raw mixture is produced, which is poured into molds. The crude mixture becomes substantially stoichiometric depending on the total surface area of the solids at a weight ratio of water / solids (without foam) of at least about 1.25 to about 1.85 and a substantially complete conversion of the silica flour and the reactive aluminates Amount of hydrated lime having a BET surface area of at least about 15 m ² / g. The ingots cast in molds are removed from the mold after sufficient solidification to a mold bottom and autoclaved on the mold bottom. The foam used is a surfactant or a protein foam. Object of the present invention is to provide a self-curing mineral foam, which has a dry weight of at most 300 kg / m ³ . This object of the invention is in each case independently achieved by the formulation mentioned at the beginning, in which the hydraulically setting binder is formed on the basis of a sulfate aluminate cement (SAC) comprising a sulfate component and an aluminum component and is contained in a proportion of at least 50 parts by weight , By a mineral foam with this formulation, by a, the mineral foam exhibiting component, by the aforementioned method in which the slurry in a second mixing stage, a foam component is added and mixed into the slurry, and then the mineral foam is cured, and by the Device in which a second mixing section is arranged downstream of the first mixing section, for mixing the slurry with a foam component.

The advantage here is that the mineral foam can be produced without required autoclaving, whereby the process can be simplified and costs can be reduced. The use of said hydraulically setting binder additionally achieves the advantage that the mineral foam does not or does not substantially disappear during hardening. It is thus u.a. achieved that provided with the mineral foam components such. With this at least partially filled hollow brick, are easier to produce by not taking into account a Schwundmaß. It is thus the degree of filling of such devices can be improved, whereby the thermal insulation can be improved in total. In addition, it can be used to achieve a mineral foam that also has fire protection properties up to approx. 1150 ° C.

The proportion of the sulfate-aluminate cement in the formulation is preferably at least 60 parts by weight, in particular at least 70 parts by weight, whereby the properties of the mineral foam can be further improved.

The statement that the sulphate-aluminate cement contains a sulphate component and an aluminum component, does not necessarily mean in the context of the invention that these are discernible phases of the cement, but merely clarifies that in the sulphate-aluminate cement S0 ₄ or S0 ₃ and aluminum are included.

The sulfate component is preferably selected from a group comprising calcium sulfate, α- or β-hemihydrate or dihydrate of calcium sulfate, anhydrite, sodium sulfate, Ferrous sulfate, magnesium sulfate, and mixtures and derivatives thereof. Hydrate phases are thereby produced during the hardening of the mineral foam, which undergo a phase transformation over time, the strength increasing. The aluminum component is preferably selected from a group comprising aluminum oxide (Al ₂ O ₃ ), aluminum hydroxides, aluminum silicates, aluminates and mixtures and derivatives thereof. It can thus be positively influenced the solidification behavior and the setting time. The ratio of the sulfate component to the aluminum component can be selected according to one embodiment from a range with a lower limit of 4:10 and an upper limit of 20:30. It is thus achieved that the setting time of the slurry does not take so long that there is a risk that the added foam will collapse, thus reducing the porosity of the mineral foam. It is thus simplified by keeping the ratio of the two components in this area, the processing.

In particular, to further improve this behavior, the ratio of the sulfate component to the aluminum component may be selected from a range having a lower limit of 6:12 and an upper limit of 13:22, preferably a lower limit of 10:18 range and an upper one Limit of 12: 24.

To improve the mechanical properties, the formulation may additionally contain Si0 ₂ particles in a proportion of not more than 10 parts by weight. However, the proportion of Si0 ₂ particles is preferably not more than 7.5 parts by weight, in particular not more than 7.5 parts by weight.

According to another embodiment, the formulation contains special Si0 ₂ particles in the form of so-called silica fumed. This is a reactive Si0 ₂ , by which the fire resistance behavior of the mineral foam can be improved by the use of energy for reactions, the SiO? In particular, carbon-free Si0 ₂ particles with a purity of at least 97% are used. In one embodiment, it is provided that the Si0 ₂ particles have a BET surface area between 5 m ² / g and 35 m ² / g, in order to increase the reactivity. Preferably, the Si0 ₂ particles have a particle size of at most 45 μπι, wherein in particular the proportion of coarse grain is limited to a maximum of 2% and the rest of Si0 ₂ - particles have a particle size of at most 1 μπι, preferably at most 0.3 μιη ,

Preferably, the Si0 ₂ particles have a BET surface area between 10 m ² / g and 25 m ² / g, in particular between 16 m ² / g and 20 m ² / g. The formulation may further contain at least one so-called high conductivity liquefier to influence the rheological behavior of the slurry formed from the formulation, provided that the addition of silica fumed, which also has a liquefying effect due to the spherical shape of the particles, is not sufficient alone for this purpose , The proportion is limited to a maximum of 3 parts by weight. In particular, when silica fumed is included in the formulation, the proportion of the high-performance plasticizer is limited to a maximum of 0.5 parts by weight, preferably at most 0.3 parts by weight.

The high-performance liquefier is preferably a polycarboxylate ether or a derivative thereof in order to be able to reduce the water content of the slurry so that less water is available for setting and thus the desired phases are formed more reliably.

It is further possible that the formulation for stabilizing the slurry and thus for better processability of the slurry at least one thickener is added in a proportion of not more than 0.5 parts by weight. The thickener is preferably added in a proportion of not more than 0.25 parts by weight, in particular not more than 0.02 parts by weight.

The thickener is preferably selected from a group comprising hydroxymethylpropylcellulose, methylhydroxyethylcellulose and mixtures and derivatives thereof since it has been found within the scope of the tests carried out for the invention that these thickeners have better properties with regard to processing, for example rheology, dispersion the solids, or the water requirement and the water retention capacity. In view of the processability of the slurry was also found that improvements occur when the proportion of thickener is not more than 70% of the proportion of Hochleistungsver- liquid. It is further possible that the formulation fibers are added in a proportion of not more than 3 parts by weight, in particular not more than 1 parts by weight, preferably 0.3 parts by weight, in order to improve the flexural strength of the mineral foam. But it can also be used to stabilize the foam component. In addition, cellulose fibers, for example, can store water, which is needed in the setting process, whereby this physically "bound" water can be better controlled with regard to the hardening of the mineral foam Cellulose fibers can also be used as thickeners.

The fibers preferably have a maximum length of 50 mm, in particular a maximum of 30 mm, and are in particular selected from a group comprising cellulose fibers, mineral fibers, glass fibers, in particular alkali-resistant glass fibers, polypropylene fibers, and mixtures thereof.

Fibers of greater length, that is, for example, with a length between 3 mm and 50 mm, in particular between 3 mm and 30 mm, preferably between 3 mm and 12 mm, whose diameter preferably between 13 μπι and 25 μπι, preferably between 13 μπι and 18 μπι, are mainly added when the bending tensile strength is to be increased. Fibers up to a length of 0.1 mm, preferably up to 30 μπ, and in particular a diameter of up to 2 μπι, preferably up to 1.5 μπι, however, are preferably added for theological reasons.

The formulation may be added to improve the rheology at least one processing aid from a group comprising an alkali metal carbonates, alkali metal sulfates, fruit acids, for example as a retarder. In order to reduce the proportion of sorption moisture in the finished mineral foam, it can be provided that at least one water repellent is added, in particular for the mass hydrophobization of the formulation. The proportion of the hydrophobizing agent on the Formulation may be up to 3 parts by weight, preferably up to 1 part by weight.

According to another embodiment variant of the formulation, it may be provided that it is free of aggregates, i. is filler-free, so contains no non-reactive constituents, whereby the density of the mineral foam could be further reduced.

Preferably, the foam component is formed by a protein foam and / or a surfactant foam. It can thus be better controlled the foaming behavior than in the method of direct foaming with a blowing agent. In particular, the pore size and the pore distribution can be influenced, and thus the heat conductivity or the sound absorption capacity of the mineral foam can be better adjusted.

Preferably, the proportion of the foam component per m ³ slurry between 30 kg / m ³ and 70 kg / m ³ , in particular between 40 kg / m ³ and 60 kg / m ³ , since thus an improvement in the properties of the mineral foam could be observed

To stabilize the foam during mixing in the slurry from the formulation with water, a surfactant may be added to the foam component.

According to a preferred embodiment, the mineral foam has a pore content of at least 70%, in particular between 80% and 95%. Due to this high proportion of pores, not only can the insulation behavior per se be improved, but it also makes it possible to achieve a lower volume weight of the mineral foam.

In this case, the pores preferably have a maximum diameter of 0.5 mm, in particular not more than 0.25 mm or not more than 0.1 mm, in order on the one hand to achieve a positive insulating behavior and on the other hand to improve the mechanical stability of the finished mineral foam.

It is also possible to add to the foam component air entraining agents, such as, for example, alkyl polyglycol ethers, alkyl sulfates or sulfonates, inter alia in order to improve the stability of the foam. According to one embodiment variant of the method, it is provided that the foam component is added to water and possibly processing aids before addition to the slurry in a foam generator, whereby its processability, in particular the stability of the foam during mixing with the slurry, can be improved. It can be arranged in the device for foaming the foam component, a foam generator, in which a protein mixed with water with a gas, in particular air, is foamed.

For a better understanding of the invention, this will be explained in more detail with reference to the following figure.

It shows in a schematically simplified representation:

Fig. 1 shows an apparatus for producing a self-curing mineral foam.

By way of introduction, it should be noted that the location information chosen in the description, such as the top, bottom, side, etc. related to the immediately described and illustrated figure and are to be transferred to the new situation mutatis mutandis when a change in position. 1 shows a device 1 for producing a self-hardening mineral foam 2.

One of the most significant advantages of the invention is that the mineral foam 2 need not be autoclaved, as is known in the art. For this purpose, the device 1 in the core of the invention has a first mixing section 3 and a second mixing section 4 disposed downstream of the latter in the direction of production. In the first mixing section 3 of powdered components of a formulation for producing the mineral foam 2, which can be kept in stock in storage containers 5, and which are fed via a conveyor 6, such as a screw conveyor, the first mixing section 3, with the addition of water accordingly Arrow 7, a so-called slurry, so a mixture of the solid components and water produced. Normally, normal tap water is used as water, it being understood that it is also possible to use distilled water. If appropriate, further additives for mixing with the pulverulent constituents can be introduced into the first mixing section 3, as indicated by a dashed arrow 8 in Fig. 1, wherein at least some of the additives can also be added in liquid or dispersed form.

It is possible that the mixing of the powdered components takes place before the addition of the water according to arrow 7, that is, that the main components of

Formulation for the preparation of the mineral foam 2 may already be added to these auxiliaries or processing aids and, if appropriate, these pulverulent components of the formulation can be premixed. The mixing section 3 is designed as a paddle mixer or plow blade mixer, although other types of mixers, such as free-fall mixer, can be used. However, the former mixer types have the advantage that less water has to be added - the goal is to use as little water as possible - and that the energy consumption per m ^{3 of} slurry is relatively low. In addition, the risk of the mixer sticking to these rounded shapes can be reduced. In particular, this mixing section 3 may comprise mixing elements 9, which are arranged offset in the radial direction on a mixing path shaft 10. It can be arranged in the mixing section 3 between 2 and 20 mixing elements 9.

This slurry is subsequently added with a protein foam and / or a surfactant foam as foam component, which is produced in a foam generator 11. Thus, the mineral foam 2 according to the invention is not foamed directly but the pore formation of the mineral foam 2 by the addition of a separate foam. The foam component used for this purpose is a protein foam and / or a surfactant foam. As protein 12, which can be kept in stock in a corresponding storage container 13, an animal or a vegetable protein or mixtures thereof is used. In particular, the protein 12 used is a keratin, preferably a hydrolysed keratin, or a soy-based protein, which is preferably alkali-resistant. The protein can be used in an amount of up to 5 parts by weight. In turn, water, in particular distilled or purified water, according to arrow 14, is added to this protein 12 and, in the foam generator 11, the protein foam is produced by blowing air in accordance with arrow 15. As shown by dashed lines in the region of the foam generator 11 in FIG. 1, processing aids, for example from a reservoir 16, can also be added to this foam component, it also being possible for a plurality of processing aids to be mixed in advance if these auxiliaries are mixed he follows.

In general, it should be noted that these processing aids for the addition of the foam component can be added in powder form or in dissolved or dispersed form.

The finished foam component is subsequently added according to arrow 17 to the slurry originating from the first mixing section 3 in accordance with arrow 18, the addition taking place in the second mixing section 4 or preferably in front of the second mixing section 4. For this purpose, this mixing section 4 can be a conveying device 19, e.g. a screw conveyor, upstream, in which case it is possible for the time being the foam is introduced into the conveyor 19 so that it is at least approximately completely filled with this, and then the slurry is added to the foam, in particular stepwise, also a plurality of filling openings for the slurry may be present in the conveying device 19. However, it is possible deviating or in addition to the fact that the slurry is added to the foam only in the second mixing section 4.

The second mixing section 4 is designed in particular as a paddle, screw, spiral mixer or static mixer or in the form of combinations thereof.

In the context of the invention, there is the possibility that the two mixing sections 3, 4 are combined in egg nem single mixer, where they are separated from each other in this case, that are formed one behind the other in this mixer.

There is also the possibility that the first and / or second mixing section 3, 4 consist of a separate conveyor device 6 and 19 and a separate mixer, the separation can only look so that they have separate drives to different speeds and thus enabling a better mixing result with the lowest possible energy input. As a result, the finished mixture of the slurry and the foam component from the second mixing section 4 is withdrawn via a corresponding conveyor 20 and this mixture can be filled into a corresponding shape to self-curing of the mineral foam 2 by the corresponding expiring, chemical reactions enable.

It should be noted that the mineral foam 2 according to the invention, for example in plate form, for subsequent application to be insulated structural parts, such as walls, may be formed, it is also possible that with the mixture components, in particular hollow brick, at least partially filled be so that so in insulated components, for example, provided with a thermal insulation bricks or stones can be produced. However, other forms and uses of mineral foam 2 are also possible, for example as fire protection material, for which higher chamber weights of mineral foam 2 are also advantageous, as granules for fillings or fillings, as building material in stone form, in particular as brick, as sound insulation material, in particular in combination with other materials, as an additive to a mortar, as a plaster base, generally as a building material, for the air conditioning of rooms, in or as fireplace in (en), etc .. Although not shown in Fig. 1, there is in the context of Invention, the possibility that appropriate control and / or control organs and / or measuring organs are present within the device 1 and these control and / or control organs and / or measuring organs can of course also be operated computer-assisted. There is also the possibility that other gases, such as N ₂ , C0 ₂ , etc., are used to produce the foam instead of air. Furthermore, there is the possibility that the protein, in particular alkaline, blowing agent is added, so that it can be dispensed with the addition of a separate gas for the foaming of the protein or the amount of gas can be reduced.

It should be noted at this point that the selected number of mixing elements 9 in the first mixing section 3, as stated above, has advantages with regard to the product properties of the mineral foam 2. Although can with a lower or higher number of Mixing rods 9 also a mineral foam 2, that is, a slurry, are produced, however, it was found in the context of testing the invention that the product properties of the mineral foam 2 are improved with a number of mixing elements 9 from the specified range. It should be noted that the number of mixing elements 9 is related to a certain size of the device 1, that is, to a certain volume output of mineral foam 2, which is up to 50 m ³ / h. It is therefore possible, although not yet tested, that a number deviating from the specified number of mixing elements 9 is advantageous in the case of another design of the system 1. Furthermore, it has been found within the scope of the invention that a circumferential speed is selected from a range with a lower limit of 4 m / s, in particular 5.5 m / s, and an upper limit of 12 m / s, in particular 11 m / s. with which the mixing path shaft 10 of the mixing section 3 is operated, for the specified production volume also has advantages in terms of the product properties of the mineral foam 2. In particular, it is advantageous if a number of 16 mixing elements 9 are arranged at a circumferential speed of 6 m / s and a number of 4 mixing elements 9 at a peripheral speed of 10 m / s of the mixing path shaft 10, these figures as the lower and upper limit a range for the number of mixing elements 9 with respect to the peripheral speed of the mixing path shaft 10 are to be understood.

It should again be noted in this connection that, in particular for the first mixing section 3, but also for the second mixing section 4, combinations of different types of mixing devices 9 can be used, for example 5 stator bars and 4 paddle bars as a rotor. In general, a combination of stator and rotor bars in the mixing sections 3, 4 can be used.

For a flow rate between 5 kg / min, in particular 15 kg / min, and 50 kg / min, in particular 35 kg / min, of the powdered constituents for the preparation of the slurry, a water volume between 150 1 / h, in particular 300 1 / h and 10001 / h, in particular 500 1 / h, the first mixing section 3 fed. Again, an interaction with the number of mixing elements 9 in the first mixing section 3 with respect to the product properties of the mineral foam 2 could be observed. It is particularly advantageous if, in the case of a number of 6 mixing elements 9, a volume flow rate of 250 l / h of water and at a number of 18 mixing elements 9 a volume flow of 8001 / h water is added to the powdered constituents of the formulation for the preparation of the slurry, whereby this information again as the lower and upper limit of a range for the number of mixing elements 9 with respect to the water volume flow to understand.

For the addition of the water to the pulverulent components in the first mixing section 3, it is advantageous if the water is distributed over several areas of the mixing section 3, in particular via spray nozzles. For example, can be arranged distributed over the circumference of the first mixing section 3 between 2 and 10, in particular between 3 and 6, spray nozzles.

For a flow rate between 7 kg / min and 40 kg / min of slurry, a volume flow of 80 l / min to 140 l / min foam component from the foam generator 11 in the second mixing section 4 is applied, for example, for 25 kg min slurry 1001 / min foam component te, so that the foam component, for example, takes a share between 40 kg and 60 kg per m ^{3 of} wet slurry on the slurry / foam mixture. Preferably, the foam component has a density selected from a range having a lower limit of 35 kg / m ³ and an upper limit of 60 kg / m ³ . The peripheral speed with which the second mixing section 4 is operated is preferably smaller than that of the first mixing section 3 in the above-described production volume and with regard to the volume flow of added foam component. The mixing elements of the second mixing section 4 are arranged such that a Homogeneous mixing within the mixing section 4 between the slurry and the foam component takes place and the foam component is gently mixed with the slurry.

It can be produced with the device 1 according to the invention and the method according to the invention, a mineral foam 2, which has a density of max. 300 kg / m, in particular a density between 100 kg / m ³ and 250 kg / m ³ . In this case, this specification refers to the completely dried mineral foam 2. The density of the volume can also be adjusted, for example, via the densities of the slurry and the foam component. The formulation from which the slurry is prepared in the first mixing section 3 consists in the simplest case of a hydraulically setting binder, a pozzolanic setting binder and a sulfate, wherein the hydraulically setting binder by a sulfate-aluminate cement (a sulfo-aluminate Cement) comprising a sulfate component and an aluminate component and contained in a proportion of at least 50 parts by weight in the powdered formulation. The proportion by weight of the sulfate-aluminate cement in the formulation is preferably at least 60 parts by weight, in particular at least 70 parts by weight. A preferred range in which the sulfate-aluminate cement is incorporated in the formulation is between 65 parts by weight and 75 parts by weight.

The pozzolanic setting binder may be a natural or, in particular, a synthetic pozzolan, for example, trass, blast furnace slag, LD slag, metakaolin. Basalt, or mixtures thereof may be formed. The proportion of the pozzolanic binder in the formulation is up to 40 parts by weight. A preferred range of pozzolanic bonding binder is between 10 parts by weight and 30 parts by weight.

As the sulfate, calcium sulfate is preferably used as the anhydrite, dihydrate and / or α-hemihydrate, but other sulfates such as β-hemihydrate of calcium sulfate as well as magnesium sulfate or sodium sulfate may be used. Optionally, mixtures and derivatives thereof can be used. The proportion of sulfate in the formulation is between 5 parts by weight and 25 parts by weight. A preferred range is between 10 parts by weight and 15 parts by weight. The added sulfate functions inter alia as a grinding aid for the formulation, in particular if it is ground before being fed to the first mixing section 3, or as an accelerator. It also improves the green strength of the slurry / foam mixture.

The sulfate component of the sulfate-aluminate cement is preferably selected from a group comprising calcium sulfate, α- or β-hemihydrate or dihydrate of calcium sulfate, anhydrite, sodium sulfate, iron (II) sulfate, magnesium sulfate, and mixtures and derivatives thereof. The proportion of the sulfate component in the sulfate aluminate cement is up to 20 parts by weight. The aluminum component of the sulfate-alumi- nated cement may be selected from a group comprising alumina, aluminum hydroxides, aluminum silicates, aluminates and mixtures and derivatives thereof. The proportion of the aluminum component in the sulfate-aluminate cement is preferably up to 30 parts by weight.

In the course of the test carried out for the invention, it was found that a ratio of the sulfate component to the aluminate component selected from a range with a lower limit of 4:10 and an upper limit of 20:30 has advantageous effects with regard to the thermal insulation behavior of the mineral foam 2. By adhering to these conditions, the green strength of the not yet hardened mineral foam 2 could be improved, whereby the processing of the mineral foam 2 can be simplified.

The pulverulent constituents of the formulation, that is to say the hydraulically setting binder, the pozzolanically setting binder and the sulfate, have in the main amount preferably a particle size of up to 40 μm and a maximum of 17% larger particles. By adhering to this freeness of the pulverulent main constituents of the formulation, the production of the slurry can be improved; in particular, this can also positively influence the porosity and the volume fraction of the pores in the mineral foam 2.

In addition to these main constituents of the formulation, that is to say the hydraulically setting binder, the pozzolanic setting binder, which is also used, inter alia, as a replacement for a proportion of the sulfate-aluminate cement, and of the sulfate, it is possible within the scope of the invention to that this formulation further, especially powdery, additives and excipients are added, but in the preferred embodiment, this formulation contains no non-reactive fillers, so all the components are reactive. As an additional ingredient, the formulation may contain Si0 ₂ particles in a proportion of not more than 10 parts by weight. In particular, a so-called silca fumed is used as Si0 ₂ , wherein in the preferred embodiment of this Si0 ₂ a BET Surface between 10 m ² / g, preferably 16 m ² / g, and 30 m ² / g, preferably 20 m ² / g.

The pozzolanic binder preferably has a Blaine value of between 3000, in particular 4000, and 6000, in particular 5400.

The sulphate-aluminate cement preferably has a Blaine value between 4000, in particular 5000, and 7000, in particular 6000. With regard to the modes of action or the reasons for the addition of these auxiliaries or processing aids, reference is generally made to the above statements.

The formulation may further comprise, in particular for the reduction of the water content, at least one high-performance liquefier in a proportion of at most 1 part by weight, with this high-performance liquefier preferably being a polycarboxylate ether.

Furthermore, the formulation may contain at least one thickener in a proportion by weight of max. 0.5 parts by weight may be added, this thickener is preferably selected from a group comprising hydroxymethylpropylcellulose, methylhydroxyethylcellulose, and mixtures and derivatives thereof.

According to a preferred embodiment, the proportion of the thickener is at most 70% of the proportion of the high-performance liquefier. Furthermore, rheology-enhancing adjuncts, such as e.g. Means of reducing the

Viscosity, be added to avoid a decrease of the solid components in the slurry.

It is also possible that the formulation fibers are added in a proportion of at most 3 part by weight, these fibers in a preferred embodiment, when used to improve the Theological properties, may have a maximum length of 200 μπι and in particular be selected may be selected from a group comprising cellulose fibers, basalt fibers, glass fibers, in particular alkali-resistant glass fibers, polypropylene fibers, and mixtures thereof. Fibers to improve the Biegezugfestigkeit be added, however, have a length of up to 50 mm, in particular between 3 mm and 12 mm.

To avoid repetitions, it should be noted at this point that reference is generally also made to the above statements with regard to the individual components of the formulation or of the slurry, of the foam component or of the slurry / foam component mixture.

Other processing aids are alkali metal carbonates, such as Li ₂ C0 ₃ , alkali metal sulfates, fruit acids such as citric acid, or tartaric acid, which may each be contained in a proportion of up to 2 parts by weight.

Preferably, the formulation also has a hydrophobizing agent in a proportion of at most 1 part by weight in order to reduce the water absorption of the finished mineral foam 2, so that thus a smaller reduction of the thermal insulation behavior, ie the thermal conductivity, can be achieved by water absorption.

The foam component may also be admixed with a surfactant to improve the service life of the foam, the proportion of the surfactant in the foam component preferably being at most 10 parts by weight.

Wetting agents known from the prior art, in particular in a proportion of up to 0.2 parts by weight, and highly viscous stabilizers, in particular in an amount of up to 0.02 parts by weight, may also be added to the foam component in order to improve the mixing with the slurry.

The mineral foam 2 produced by the process according to the invention has pores which have a diameter of at most 1 mm and may be present in a proportion of the mineral foam of 80%.

In the course of tests carried out, the following exemplified compositions of the formulation according to the invention for the slurry according to Table 1 were prepared. This was as a pozzolanic setting binder metakaolin for Examples 1 to 7 and Basalt used for Examples 8 to 15. As sulfate, α-hemihydrate of calcium sulfate was used for Examples 1 to 9 and the dihydrate of calcium sulfate for Examples 10 to 15. The foam component was compounded as described in Table 2 using protein hydrolyzed keratin for Examples 1-15. Subsequently, the slurry / foam compositions were prepared according to Table 3, where the number corresponding to the number of Examples in Tables 1 and 2 respectively. All information on the compositions in the tables are to be understood as parts by weight based on the total formulation (Table 1) or based on the slurry / foam mixture (Table 2).

It should be noted that in the context of the invention, compositions were also prepared with the other substances mentioned above. The values obtained for the measured properties of the mineral foam 2 are in the range of the specified values according to Table 3, so that the representation of these examples is omitted, since this would go beyond the scope of this description.

Of these compositions, the thermal conductivity was measured according to EN 1946-2, as well as the compressive strength at a stress of the mineral foam 2 with 0.1 MPa to 0.5 MPa and the corresponding values are given in Table 3.

Table 1: Slurry composition

No SAC Puzzolan sulfate auxiliaries water

1 40 40 25 5 35

2 50 40 25 5 35

3 50 30 15 2 25

4 50 30 15 2 35

5 55 20 10 5 35

6 60 20 10 5 30

7 70 20 15 8 30

8 70 20 12 6 30

9 70 15 10 6 25

10 70 15 10 7 25 11 70 10 10 7 20

12 75 10 10 8 20

13 75 10 15 8 20

14 75 5 10 9 20

15 80 5 10 10 18

Table 2: Foam composition

No protein water auxiliaries

1 1 60 0

2 1 55 0.2

3 1 50 0.2

4 1 45 0.2

5 1 40 0.2

6 2 60 0.2

7 2 40 0.2

8 2 20 0.5

9 3 60 0.5

10 3 50 0.5

11 3 40 0.5

12 3 30 0.5

13 3 20 1

14 4 60 1

Table 3: Slurry / foam composition

With regard to the auxiliaries used, reference is made to the above statements.

In addition, it should be noted that the addition of the foam component to the slurry in addition to the described and preferred continuous procedure can also be carried out batchwise.

The embodiment shows a possible embodiment of the device 1, wherein it should be noted at this point that the invention is not limited to the specifically illustrated embodiment of the same. For the sake of order, it should finally be pointed out that, for better understanding of the structure of the device 1, these or their components have been shown partially unevenly and / or enlarged and / or reduced in size.

REFERENCE NUMBERS

1 device

2 mineral foam

3 mixing section

4 mixing section

5 storage containers

6 conveyor

7 arrow

8 arrow

9 mixing organ

10 mixing shaft

11 foam generator

12 protein

13 storage tank

14 arrow

15 arrow

16 reservoir

17 arrow

18 arrow

19 conveyor

20 conveyor

Claims

Patent claims

A formulation for producing a self-curing mineral foam, comprising a hydraulically setting and a pozzolanic setting binder and a sulfate, characterized in that the hydraulically setting binder is formed by a sulfate-aluminate cement, comprising a sulfate component and an aluminum component, and in one Share of at least 50 parts by weight is included.

2. Formulation according to claim 1, characterized in that the sulfate component is selected from a group comprising calcium sulfate, α- or β-hemihydrate or

Dihydrate of calcium sulfate, anhydrite, sodium sulfate, ferrous sulfate, magnesium sulfate and mixtures and derivatives thereof.

3. Formulation according to claim 1 or 2, characterized in that the aluminum component is selected from a group comprising alumina, aluminum hydroxides, aluminum silicates, aluminates and mixtures and derivatives thereof.

4. A formulation according to any one of claims 1 to 3, characterized in that a ratio of the sulfate component to the aluminum component is selected from a range with a lower limit of 4:10 and an upper limit of 20:30.

5. A formulation according to any one of claims 1 to 4, characterized in that it contains Si0 ₂ particles in a proportion of not more than 10 parts by weight.

6. Formulation according to claim 5, characterized in that the Si0 ₂ is fumed a sili- ca.

7. Formulation according to claim 5 or 6, characterized in that the Si0 _{2 has} a BET surface area between 5 m ² / g and 30 m ² / g.

8. A formulation according to any one of claims 1 to 7, characterized in that it contains at least one Hochleitstungsverflüssiger in a proportion of not more than 3 parts by weight.

9. Formulation according to claim 8, characterized in that the high-performance liquefier is a polycarboxylate ether or a derivative thereof.

10. A formulation according to any one of claims 1 to 9, characterized in that it contains at least one thickener in a proportion of not more than 0.5 parts by weight.

11. Formulation according to claim 10, characterized in that the thickener is selected from a group comprising hydroxymethylpropylcellulose, methylhydroxyethylcellulose, and mixtures and derivatives thereof.

12. A formulation according to claim 10 or 11, characterized in that the proportion of the thickener is at most 70% of the proportion of high-performance liquefier.

13. A formulation according to any one of claims 1 to 12, characterized in that it contains fibers in a proportion of not more than 3 parts by weight.

14. A formulation according to claim 13, characterized in that the fibers have a maximum length of 50 mm.

15. A formulation according to claim 14, characterized in that the fibers are selected from a group comprising cellulose fibers, basalt fibers, glass fibers, in particular alkali-resistant glass fibers, polypropylene fibers, and mixtures thereof.

16. A formulation according to any one of claims 1 to 15, characterized in that at least one substance from a group comprising an alkali metal carbonates, alkali metal sulfates, fruit acids, is included.

17. A formulation according to any one of claims 1 to 16, characterized in that at least one hydrophobizing agent is included.

18. A formulation according to any one of claims 1 to 17, characterized in that it is free of additives.

19. Mineral foam comprising a hydraulically setting component and a

Foam component, characterized in that the hydraulically setting component is formed by a formulation according to one of the preceding claims.

20. Mineral foam according to claim 19, characterized in that the foam component is formed by a protein foam and / or a surfactant foam.

21. Mineral foam according to claim 19 or 20, characterized in that the proportion of the foam component per m ³ slurry between 30 kg / m ³ and 70 kg / m ³ , in particular between 40 kg / m ³ and 60 kg / m ³ .

22. Mineral foam according to one of claims 19 to 21, characterized in that the foam component contains a surfactant.

23. Mineral foam according to one of claims 19 to 22, characterized in that a proportion of the pores is at least 70%.

24. Mineral foam according to one of claims 19 to 23, characterized in that the pores have a diameter of not more than 0.5 mm.

25. Component with a component body, characterized in that on a surface of the component body and / or within the component body, a mineral foam according to one of claims 19 to 24 is arranged.

26. A method for producing a self-curing mineral foam according to the pulverulent constituents for producing a formulation according to any one of claims 1 to 18 in a first mixing section (3) are mixed together to form a mixture and this mixture is added to form a water slurry, characterized in that a foam component is added to the slurry in a second mixing section (4) and mixed into the slurry, and then the mineral foam is hardened.

27. The method according to claim 26, characterized in that the foam component is added before adding to the slurry in a foam generator with water and optionally processing aids.

28. The method according to claim 26 or 27, characterized in that the proportion of the foam component per m ³ slurry between 30 kg / m ³ and 70 kg / m ³ ,

29. Device (1) for producing a self-hardening mineral foam comprising a first mixing section (3) for producing a slurry of pulverulent components and water, characterized in that a second mixing section (4) is arranged downstream of the first mixing section (3) Mixing the slurry with a foam component.

30. The device according to claim 29, characterized in that for foaming the foam component, a foam generator (11) is arranged, in which a protein mixed with water is foamed with a gas.