DE102008001176A1 - Moldings, especially molded panels, are produced from composition comprising cement, fly ash, aluminum oxide, iron oxide and anhydrite - Google Patents

Abstract

Moldings, especially molded panels, are produced from a composition comprising (wt%): cement 20 - 40; fly ash 40 - 70; aluminum oxide 5 - 15; iron oxide 0 - 5 and anhydrite 0 - 5. An independent claim is included for a method for making the moldings comprising: (A) mixing the components; (B) adding water before or during mixing; (C) adding a foam builder; (D) filling a mold with product; (E) keeping the mold at a specified temperature to produce a preform, removing it; and (F) heat-treating it to produce the final molding.

Description

The The present invention relates to a molded article, in particular a mold plate, made of cement, fly ash, alumina, iron oxide Anhydrite and a method for producing such Moldings.

in the Building materials sector and in the construction industry are getting higher Requirements placed on the components used. Especially made of concrete components are not just for load-bearing Structures that include reinforcing elements are used, but For example, serve as sound-absorbing elements for Noise barriers or similar walls.

Sound-absorbing components are for example from the DE 20 2006 008 233 U1 . DE 103 38 213 A1 . DE 100 20 955 A1 or off DE 39 16 299 A1 known. Often, in the use of absorbent components, expanded glass, expanded glass granules or bleach granules are used in order to achieve the best possible noise suppression.

Especially when using the known components as a plate-shaped Shaped body reduces its absorption capacity clear. In part, the current requirements to the sound absorption no longer or only in use be met by particularly thick absorption plates.

task It is therefore the object of the present invention to provide a shaped body, in particular a mold plate to provide their absorption capacity is significantly improved.

Solved the present object is achieved by a shaped body, in particular a mold plate, with the features of claim 1 and by a method for the production of moldings with the features of the claim 7. The retrospective dependent claims each have preferred embodiments of the molding or the manufacturing process on.

The molding according to the invention comprises the components cement, fly ash, aluminum oxide (Al ₂ O ₃ ), iron oxide (Fe ₂ O ₃ ) and anhydrite. According to the invention, the composition of the ingredients is such that 20% by weight (wt.%) To 40 wt.% Of cement is present. The proportion of fly ash is between 40 wt .-% and 70 wt .-%. Aluminum oxide is present at a level of from 5% to 15% by weight, while iron oxide has a proportion of from 0% to 5% by weight. The component anhydrite has a content of 0 wt .-% to 5 wt .-%. A molding with these components is referred to in the art as a hydrosilicate molding (or hydrosilicate plate) and is a conglomerate of hydrogranates and hydrosilicates.

Of the Shaped body according to the invention has a lot positive properties in terms of its absorption capacity on. He is not just for airborne sound insulation suitable but also has very good (air) sound absorbing properties. Therefore, it is particularly suitable for use in the form of a mold plate for Sound reduction to be used. The airborne sound is through not only dampened the mold plate according to the invention, but also absorbed. The hydrosilicate plate with the above Composition also has a very high resistance to aging, so that they self-over a period of several not changed for ten years.

In a particular embodiment, the proportion of cement in the shaped body in the range of 25 wt .-% to 35 wt .-%, preferably from 28% to 30% by weight. Particularly preferred is the Proportion of cement at 29% by weight for such a plate.

Also preferred is an absorption plate whose proportion of fly ash in the range from 45% to 65% by weight, preferably between 50% by weight and 55% by weight. Very much preferred is a content of 53.5% by weight. Fly ash.

In a further preferred embodiment of the shaped body, the proportion of aluminum oxide (Al ₂ O ₃ ) is in the range from 8% by weight to 13% by weight, preferably from 10 to 12% by weight. Particularly preferred are 11% by weight of Al ₂ O ₃ .

Likewise preferred is a molded article whose iron oxide content (Fe ₂ O ₃ ) is in the range from 1.5% by weight to 5% by weight, preferably from 2% by weight to 4% by weight. The proportion is particularly preferably 3.5% by weight.

Of the Proportion of anhydrite in the overall composition of the molding is preferably between 1.5% by weight and 5% by weight, preferably between 2 wt .-% and 4 wt .-%. Particularly preferred the proportion of anhydrite 3 wt .-%.

Especially preferred is an embodiment of the shaped body or the mold plate with the composition of 29 wt .-% cement, 53.5 wt .-% fly ash, 11 wt .-% wt .-%, 3.5 wt .-% iron oxide and 3 wt .-% anhydrite. Such a mold plate has very good properties in terms of the absorbency of sound and is very resistant to aging.

As fly ash is thereby formed in thermal power plants during combustion solid, disperse (particulate, particulate or dust-shaped) Backlog called. The particle size of the fly ash is approximately between 1 micrometer and 1 millimeter. Preference is given to high-quality fly ash, as it is known and used in the building materials industry.

In According to one embodiment, the shaped body is inner Capillary channels arising from single isotropic capillaries be formed. These preferred long-chain capillaries or capillary channels go through the entire molded body. Under capillary channels are preferably arbitrarily shaped, elongated recesses understood, preferably from a plurality of cavities whose connection is formed. The capillary channels are preferred open to the outside and (inside) connected. Such a molded body made of cellular concrete has due to its isotropic capillaries inside very good absorption properties. On the mold impacting airborne sound is in the Capillary channels initiated and absorbed by these. A reflection of airborne sound at the surface of the molding is thus significantly reduced. The biggest part the sound enters the molding and becomes quasi absorbed. Again emerging from the molding body sound is very much reduced and runs quasi in the connected Capillary channels dead. An escape of the sound or even a reflection of the sound at the plate takes place diffusely, so that already the impression of a sound reduction or insulation he follows. The sound absorption coefficient α of the shaped body is greater than 60% in the frequency range from 600 hertz, in the range between 800 and 1050 hertz larger 80% percent.

in the Within the scope of the invention, it has been found that the shaped body not only has very good sound-absorbing properties. Due to the Isotropic capillaries in the cell concrete is the shaped body also suitable for humidification and / or dehumidification. The capillary channels can absorb a large amount of moisture and give them slowly and delayed back to the environment from. The water absorption capacity of the molding according to the invention is about 600 liters per cubic meter. By the moisture absorption and the storage of moisture, for example, the plate for Humidification and dehumidification of rooms can be used. The molded body thus creates a very pleasant room climate. Possible applications of the material are therefore also the mold control.

in the Under the invention it has been found that in the case of a shaped body with about 6.5 kilograms of moisture content in the dry state 0.9 percent by volume. After storage at 23 degrees Celsius Room temperature and 80 percent relative humidity to the Constant mass results in a mean equilibrium moisture content of 1.7 volume percent.

in the In addition, it has been found that that the moldings also for hydroponics are suitable because they have a very high water absorption capacity.

Of the Shaped body according to the invention has it In addition the advantage that he has very good environmental compatibility having. In particular, it is very suitable for allergy sufferers, because no allergenic substances are used. The molded body is therefore particularly suitable for use in home construction for sound insulation or for dehumidifying cellar rooms.

Of the Shaped body is easy after use recycle because it contains no pollutants. In its Composition already corresponds to the cycle of economic and waste law, so that the moldings easy the recycling cycle can be supplied.

by virtue of the aforementioned properties of the fiber-free hydrosilicate plate is their field of application diverse. For example it is possible, shaped bodies in the area of the road, Railway and aviation use; they are great as Noise barriers.

About that In addition, they can be used as wall coverings for the Salt protection can be used. Further applications are in the Area of acoustic walls or acoustic ceilings. As a broadband absorber They can with slotted, perforated or raised surface structures be equipped to operate over a wide frequency range Absorb sound. Due to their material properties are They are also suitable to be used in exhaust mufflers (for example as a core material).

In a preferred embodiment of the molding, its density is between 100 and 400 kilograms per cubic meter, preferably between 200 and 300 kilograms per cubic meter. In a particularly preferred embodiment, the density is 230 to 270 kilograms per cubic meter. Its compressive strength is approximately in the range of 1.0 to 1.5 Newton per square millimeter (N / mm ² ), the bending strength is in the range of 0.5 to 1 N / mm ² .

at the use as building material is to be noted that the shaped body is not flammable and thus categorized into class A1.

Another advantage of the shaped body according to the invention is that, in particular, the absorption plates are very easy to process. The plates can be glued, depending on the application be screwed or poured. For example, because of their inherent stability, they can also be clamped between two holders, in particular if they are used as soundproof walls.

to Solution of the above object is an inventive Process for the production of moldings proposed. In particular, can thus be inventive Produce moldings or mold plates. The production the molded body takes place in several steps. The components Cement and fly ash are mixed in a mixer. The mixture Batchwise. Particularly preferred are as further components Added alumina, iron oxide and / or anhydrite added. The exact one Composition of the individual components depends on the Properties of the molding, but defines itself in the context of the above composition, the proportion of Fly ash dominates. Of course you can be included more components.

In front or during the mixing of the dry components water is added to the mixture. Preferably, the Proportion of water at about 2/3 of the mass of the mixture from the dry Individual components. The proportion of water is preferably between 50 and 75 weight percent to the sum of the individual components.

in the further process step, a foaming agent is added. This is preferably done in a (horizontal) agitator, which preferably comprises a screw mixer with a worm wheel.

Of the Foaming agent is preferably a sugar-based synthetic product, which is added slowly. The foaming agent thus comprises glucose derivatives and is preferably hydrophobic. For example, the foaming agent based on an oleic acid and has in part a protein base, so includes proteins. The dosage of the Foaming agent takes place depending on the desired density. The use of a foaming agent makes the formation of individual promoted and supported (gas or) air-containing cells (pores).

Either the component water as well as the foaming agent are used as long added until a desired volume is reached becomes. Once a homogeneous mixing and the desired Volume is present, the mixture is poured into a mold and then at a predefined preheating temperature tempered until the mixture forms a dimensionally stable blank. In a further step, the blank is removed from the mold and a heat treatment at a predetermined process temperature and a predetermined process pressure over a defined one Time exposed to form a molding. The finished molding can then be processed further.

By the method according to the invention makes it possible to form moldings from the above-mentioned components, which have large cell capillaries in open cells. The isotropic capillaries formed during production in a cellular concrete form the basis for the very good absorption properties that allow both sound absorb as well as absorb large amounts of moisture and slowly give them back to their surroundings.

According to the invention the open-celled structure of the finished material is formed by that the manufacturing process takes place in several stages. To the formation of the mixture and filling into a mold is preferred in a first process stage through the use of ferrite-containing raw materials formed a stable chain of hydrogranates. In this process stage, which takes place before tempering is the mixture filled in a mold for at least 30 minutes, preferably at least 45 minutes, and more preferably stored for at least 60 minutes at a predetermined temperature. Very preferred is an intermediate storage of at least 90 minutes. The Storage at temperatures between 20 to 40 degrees Celsius can be done in a special heat chamber or take place in a warehouse. In special cases, the intermediate storage should no longer be take as 90 minutes. In terms of an economic Process flow is the storage temperature depending on to choose and optimize the composition of the components.

In a second stage after storage is filled into molds Tempered mixture. The temperature control preferably takes place in a heating chamber instead, whose temperature is about 10 to 50 degrees Celsius warmer is than the mixture introduced into the heating chamber. Prefers the temperature of the heating chamber is 10 to 30 degrees Celsius warmer than the mixture in the mold, too is called green body. The process of Tempering preferably takes place at a humidity of 50 up to 80 percent instead, which is favored by a regulation of the heat chamber is kept constant.

The process step of tempering lasts at least 12 hours, preferably at least 24 hours, and most preferably at least 36 hours. In a particularly preferred embodiment of the method, the mixture is introduced into the heating chamber for at least 48 hours. Within the heat chamber, more are formed in the mixture during the tempering process Hydrogranates that get harder. By hardening the cement (for example in the form of tobermorite), the cells in the mixture increase by about 7 to 25 volume percent. The warming increases the air trapped in the individual cells (pores), which tries to evaporate. The individual cell walls are broken up; capillaries form. In this process step, the air is heated in the large number of existing pores, which expands and the cells connects and opens. As a result, an extreme capillary structure is formed with preferably long-chain capillaries. At the same time, during the process stage of tempering, the actual mass of the mixture is solidified in a natural strength process. The mixture becomes a dimensionally stable blank.

In a preferred third stage of the invention Manufacturing process is the blank of a heat treatment undergone in an autoclave (hardening kettle). The heat treatment is preferably carried out at a pressure of approx. 8 to 20 bar performed. Particularly preferred is the Pressure between 10 and 14 bar. By the pressure in the autoclave becomes promoted the breaking up of individual cells, so that the networking of the cells into a capillary structure and several Cavities is supported. The individual cavities are while gas-containing, preferably containing air.

In In a preferred embodiment, this third stage of the manufacturing process include two sections in each of which a temperature change with different rates of change can be provided.

In front the heat treatment of the blank and after tempering The blanks are made from the molds used for the manufacturing process tempering were necessary, turned off. For production of Molded panels are cut the moldings accordingly.

The molded article produced by the production process according to the invention or the molding plate is distinguished by the fact that a solid solution is formed between four different compounds which, for example, are preferably hydrogranates. A fixed position solution is a grid structure in which the individual components always have the same position and neighborhood. The four compounds of the fixed solution are:
C ₃ FH ₆
C ₃ FS ₃ (Andradite)
C ₃ AH ₆
C ₃ AF ₃ (Grossular, Grosulartrit)

Here, the placeholder C stands for calcium (Ca), A for aluminum ₂ (Al ₂ ), H for water (H ₂ O), F for iron ₂ (Fe ₂ ) and S for a silicon oxide (Si ₃ O ₄ ). For example, for Andradit the formula: Ca ₃ Fe ₂ Si ₃ O ₁₂ results, for Grosulartrit (CA ₃ Al ₂ Si ₃ O ₁₂ ).

The Invention will be described below with reference to those in the figures preferred embodiments explained in more detail. The peculiarities shown therein can be individual or used in combination to further preferred embodiments to provide the invention. The described embodiments do not restrict the generality of the in the Claims defined subject matter or method dar demonstrate:

1 a schematic diagram of the method according to the invention; and

2 additional optional process steps.

1 shows the process flow of the manufacturing method according to the invention. In one with 1 designated filling station, the components of cement, fly ash, alumina, iron oxide and anhydrite in a container 2 filled. About a pipeline 3 Water is added to the ingredients. In the container 2 is a stirrer 4 arranged, by means of which a matrix mixture of the components and water is produced. The mixture is placed in a vertical mixer 5 with a vertical worm wheel 6 filled from formed stirrer, which is operated by a motor. A foaming agent is via a foam gun 7 the vertical mixer 5 fed. The mixture is mixed in the vertical mixer until the volume of the mixture has reached a certain, predetermined volume. The foaming agent and water can be replenished as needed to increase the volume.

In a filling station 8th the mixture is filled into individual molds that are stored in a storage station 9 be stored. The storage takes place at temperatures between 20 and 40 degrees Celsius for preferably 45 to 90 minutes. From the storage station 9 become the filled molds with the mixture in a preheat chamber 10 in which the mixture is stored for at least 12 hours. The preheat chamber can be heated and operated with a predetermined humidity, which is between 50 and 95 degrees of humidity, more preferably 80 degrees does not exceed atmospheric humidity. The air within the preheat chamber is recirculated to provide constant temperature and humidity conditions.

In the preheating chamber, the Vo increases during the preheating process (tempering) lumen within the cells of the mixture by 7 to 25 volume percent. At the end of the tempering process, a dimensionally stable blank has emerged from the mixture, which is in a stripping station 11 is turned off from the molds. The blanks are placed in an intermediate processing station 12 processed in an intermediate processing step, for example, a block-like molded body is cut into sheets of desired thickness and size. Preferably, the plates have a thickness of 20 to 40 millimeters.

Subsequently, the plates are stored at a distance on a rack or stacked on top of each other. The usually mobile frame is in an autoclave together with the spaced plates in a next processing step 13 introduced, in which a heat treatment of the processed blank takes place. The individual plates are exposed at a pressure of 10 to 14 bar a temperature between 140 and 200 degrees Celsius (° C). The hydrothermal heat treatment in the autoclave preferably takes place in two process sections:
In the first process section, the temperature (preferably starting from room temperature) is increased by about 20 ° C. per hour until a temperature of about 140 ° C. is reached. During this phase of the temperature rise further hydrogrencates and capillaries are formed in the blank. Individual cells literally burst and connect with each other to form long-chained channels.

In a second portion of the heat treatment becomes a temperature increase with a temperature change between 23 ° C per Hour and 30 ° C per hour, preferably with a temperature change held at 25 ° C per hour. The temperature will stay that way increased until a final temperature of at least 170 ° C, preferably at least 180 ° C and more preferably at least 190 ° C is reached. Preferably, the final temperature is below 200 ° C, preferably below 195 ° C.

in the first process section is preferably a final temperature (intermediate end temperature) of at least 120 ° C and at most 150 ° C, preferably reached at most 140 ° C.

To the second process section of the heat treatment has the Material achieves its desired strength and can be used.

2 shows further optional manufacturing steps or stations: In a further step is in a drying station 14 The shaped body is dried before being stored 17 is stored for delivery.

Optionally, the molding after drying in the drying station 14 in a kiln 15 at a temperature between 1000 ° C and 1400 ° C for a predetermined time, preferably several hours, fired. Due to the firing process, a ceramic product can be formed from the shaped body.

Another process step may be a finishing station 16 include, in which the individual moldings or mold plates are aftertreated. This may include, for example, aging as well as finishing or special treatment such as coating or grinding or the like. Also, the moldings present as blocks can be shrunk. In the finishing station 16 or in the storage station 17 The mold plates are provided with special brackets so that they can be installed on site without unnecessary assembly steps.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 202006008233 U1 [0003]
• - DE 10338213 A1 [0003]
• DE 10020955 A1 [0003]
• - DE 3916299 A1 [0003]

Claims (16)

Shaped body, in particular a molding plate, comprising the constituents cement, fly ash, aluminum oxide (AL ₂ O ₃ ), iron oxide (Fe ₂ O ₃ ) and anhydrite, the constituents having the following composition: 20-40% by weight of cement, 40-70% by weight Fly ash, 5-15% by weight of alumina, 0-5% by weight of iron oxide and 0-5% by weight of anhydrite. Shaped body according to claim 1, characterized the proportion of cement ranges from 25% by weight to 35% by weight, preferably from 28% by weight to 30% by weight, very preferably 29% by weight and / or the proportion of fly ash in the range of 45% by weight to 65 wt .-%, preferably from 50 wt .-% to 55 wt .-%, very preferred 53.5 wt .-% is. Shaped body according to claim 1 or 2, characterized the proportion of alumina ranges from 8% by weight to 13% Wt .-%, preferably from 10 wt .-% to 12 wt .-%, more preferably 11 wt .-% is and / or the proportion of iron oxide in the range from 1.5% by weight to 5% by weight, preferably from 2% by weight to 4% by weight, particularly preferably 3.5% by weight, and / or the proportion of Anhydrite in the range of 1.5 wt .-% to 5 wt .-%, preferably from 2 Wt .-% to 4 wt .-%, more preferably 3 wt .-% is. Shaped body according to one of the preceding claims, characterized in that it has inner, preferably long-chain capillary channels having. Shaped body according to one of the preceding claims, characterized in that its density is between 100 and 400 kilograms per cubic meter, preferably from 200 to 300 kilograms per cubic meter and more preferably between 230 and 270 kilograms per cubic meter is. Shaped body according to one of the preceding claims, characterized in that a firm solution between the following compounds is formed: Ca ₃ Fe ₂ (H ₂ O) ₆ Ca ₃ Fe ₂ (Si ₃ O ₄ ) ₃ Ca ₃ Al ₂ (H ₂ O ) ₆ Ca ₃ Al ₂ (Fe ₂ ) ₃ Process for the production of moldings, in particular mold plates comprising the components cement, alumina, Iron oxide, fly ash and water with the following steps: by mixing the components cement, alumina, iron oxide and fly ash in a mixer to form a mixture; Add of water before or during mixing; Add a foaming agent to the mixture; Filling in the Mixture into a mold; Tempering the filled in the mold Mixture at a predefined preheating temperature, until the mixture forms a dimensionally stable blank; Removal of the Blanks from the mold; Heat treatment of the blank with a predetermined process temperature and a predetermined one Process pressure over a defined process time, around a molded part to build; Method according to claim 7, characterized by further step: Mix the components until a predetermined density arises. A method according to claim 7 or 8, characterized through the following step: Burning the molding with a Firing temperature between 900 and 1,400 degrees Celsius to manufacture a ceramic molding. Method according to one of claims 7 to 9, characterized by the following step: dry out the moldings for a predefined time at room temperature, preferably for at least 24 hours. Method according to one of claims 7 to 10, characterized in that the mixture of the components in one Agitator is mixed with the foaming agent, with preference the agitator a screw mixer with a worm wheel includes. Method according to one of claims 7 to 11, characterized in that the temperature control with a preheating temperature takes place in a heating chamber whose temperature is 10-30 Celsius is warmer than the temperature of the introduced mold and / or wherein the preheating time is at least 12 hours, preferably at least 24 hours, more preferably at least 36 or more preferably at least 48 hours. Method according to one of the preceding claims 7 to 12, characterized in that before the tempering with a Preheating the filled in a mold mixture for at least 30 minutes, preferably at least 45 minutes, more preferably at least 60 minutes, and most preferably at least 90 minutes at a temperature between 20 and 40 degrees Celsius is stored. Method according to one of claims 7 to 13, characterized in that the heat treatment of the blank in an autoclave at egg nem pressure of 8-20 bar, preferably is carried out at a pressure of 10-14 bar. Method according to claim 14, characterized in that that the heat treatment of the blank is a first process phase includes, in which a temperature increase of 20 degrees Celsius per Hour to a final temperature of at least 120 degrees and at most 150 degrees Celsius, preferably at most 140 degrees Celsius, is carried out. Method according to claim 15, characterized in that that the heat treatment of the blank a second process phase includes, in which the temperature rises to 25 degrees Celsius per hour at least 170 degrees Celsius, preferably at least 180 degrees, especially preferably at least 190 degrees Celsius, is increased.