Composition for producing components

Abstract

According to the invention, there is provided a composition for producing a component, comprising a solid component comprising at least one base material and metaclay, and an activation solution comprising more than 5% by mass of an alkali metal silicate, the mass of the base material being between 200% and 500% by mass of the metaclay, the mass of the metaclay being between 200% and 500% by mass of the base material, and the mass of the metaclay being between 200% and 500% by mass of the metaclay. And the ratio of the mass of the activating solution to the mass of the partial clay is greater than 1. Furthermore, a method for producing a component is provided in which, in a first step, a mixture of compositions comprising a solid component comprising at least one base material and metaclay and an activation solution is prepared, characterized in that the activation solution comprises more than 5% by mass of an alkali metal silicate, the mass of the base material is between 200% and 500% of the mass of the metaclay, and the ratio between the mass of the activation solution and the mass of the metaclay is greater than 1, in a second step, the mixture is formed into a component using an extruder.

Description

Technical Field

[0001] The present invention relates to a composition for producing components, comprising a solid component and an activating liquid, wherein the solid component comprises at least one base material and meta-Tonerde clay. Background Technology

[0002] Various compositions and methods for producing components (such as bricks or walls) are known from the prior art. Wall blocks can be, for example, chiseled directly from rock, or formed into mud bricks or clay bricks and fired to obtain sufficient strength for wall construction.

[0003] A known method for producing geopolymer components is to prepare a geopolymer composition and then extrude it to form the component. EP2727894B1 describes a specific composition or method for producing geopolymer components. In this method, a clay, clay, and an activating liquid are first mixed together, then the resulting composition is extruded, and finally the shaped component is dried. Clay is added to the composition used, at a mass ratio of 5% to 40% of the clay by weight. The ratio of the activating liquid to the solid components (especially the clay and clay) is between 0.25 and 0.85. The activating liquid also contains sodium silicate or potassium silicate at a mass ratio between 0% and 20%. This method can be used to produce components with strengths up to about 30 MPa.

[0004] A drawback of known methods or compositions for producing geopolymer components is their low strength, which is far lower than that achievable with, for example, conventionally fired bricks. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a composition that enables the creation of a final component with higher strength.

[0006] According to the present invention, in the composition of the type mentioned at the beginning of this document, the activating liquid contains more than 5% by mass of alkali metal silicate, the mass of the base material is 200% to 500% of the mass of the clay, and the ratio between the mass of the activating liquid and the mass of the clay is greater than 1.

[0007] According to the invention, the solid component therefore comprises clay. Furthermore, the solid component comprises a base material, which is preferably composed (only) of clay, (only) of sand, or of both clay and sand. Moreover, the mass of clay and / or sand is 200% to 500% of the mass of the clay. If the base material contains only clay and no sand, the mass of clay is 200% to 500% of the mass of the clay. If the base material contains only sand and no clay, the mass of sand is 200% to 500% of the mass of the clay. Preferably, the base material comprises clay and sand or is composed of both. Particularly preferred is the mass ratio of clay to sand between 0.2:1 and 4:1, preferably between 0.5:1 and 2:1, particularly preferably between 0.8:1 and 1.2:1, and especially about 1:1.

[0008] The composition can be mixed to form a substantially homogeneous substance, which is then used to form components. The substance provided by the composition is also preferably kneadable to ensure good formability. The composition preferably contains no other components besides the explicitly listed components (particularly the base material, clay, and activating liquid), except for possibly small amounts of impurities.

[0009] Clay (or clay minerals) comprises layered silicates having a layered crystal structure composed of silicon and oxygen, as well as hydrogen and conventional magnesium and aluminum. The silicate anions consist of layers of corner-connected SiO4 tetrahedra. Examples include, for instance, mica, chlorite, montmorillonite, and kaolin. The clay may be dry or wetted before being mixed with other components. Preferably, the clay is not heat-treated before being mixed with the other components of the composition according to the invention.

[0010] In this invention, meta-kaolin can be understood as clay that has been treated at high temperatures (approximately 500°C to 900°C) to remove bound water and whose structure or lattice has been altered. Meta-kaolin is primarily composed of reactive silica and alumina. A well-known example is metakaolin, which is kaolin treated at approximately 550°C to 850°C.

[0011] By mixing the compositions according to the invention, a geopolymer is formed due to a chemical reaction between the solid components (particularly clay) and the activating liquid. The geopolymer according to the invention has the following properties: after a curing period (approximately 14 days) following the formation of the component, it exhibits a high compressive strength, for example, approximately 60 MPa (N / mm²). Furthermore, no active application of heat or pressure is required during curing. Therefore, curing can be carried out in ambient air. Preferably, curing is carried out at an air temperature of at least 20°C and a humidity (rH, relative humidity). Curing is particularly preferably carried out at an air temperature of 20°C to 30°C and an air relative humidity of 50% to 90%, preferably 50% to 80%.

[0012] Preferably, the base material comprises sand, preferably quartz sand, wherein the mass of the sand is preferably 10% to 500% of the mass of the clay, particularly preferably 100% to 300% of the mass of the clay. This further improves the strength of the composition upon drying. The solid components (especially clay and clayey material, and possibly sand) are preferably in powder form when mixed with the activating liquid. The sand can be dry or wet before being mixed with other components.

[0013] The sand (especially quartz sand) preferably has a particle size of 0.05 to 0.5 mm, particularly preferably 0.1 to 0.2 mm.

[0014] The moisture content of each component (especially clay and / or sand) can be determined before or during the preparation of the composition. If necessary, the formulation of the composition can be adjusted, for example by adding more or less water to the activating solution.

[0015] The base material may also be or include one or more of the following materials: ■ Wood (materials), for example ○ Single-layer strip ○ Single-layer veneer scraps ○ Wood shavings (preferably 100 to 200 mm in length, 10 to 50 mm in width, and 0.6 to 1.5 mm in thickness) ○ Wood chips (preferably 0.5 to 3 cm in length) Wood chips, wood strips, wood veneer ■ Plastic (scrap), for example ○ Finely ground plastic powder (preferably with a particle size of 0.15 to 0.50 mm) ○ Grinded or extruded plastic granules (preferably with a particle size of 1 to 5 mm) ○ Shredded plastic pieces ■ Recycled materials, such as ○ Made of plastic ○ Made of building materials, ceramics, paving materials and / or metals ○ Derived from mineral construction waste (preferably ground to a particle size of 0.1 to 50 mm) ■ Lightweight mineral fillers, such as ○ Glass ball ○ Polystyrene, such as expanded polystyrene EPS (“foamed plastic”) or extruded polystyrene XPS ○PU foam (scrap material) ○ Lightweight filler materials, such as foam, expanded clay, expanded glass, expanded shale, foamed glass, perlite, vermiculite, cellulose fibers or sheets, and foamed plastics. ■ Glass (scrap), for example Broken glass ○ Optical functional elements, such as glass spheres used as reflectors ■ Fibers, for example ○ Mineral wool, glass fiber, carbon fiber, wood fiber, plant fiber, straw, hair ■ Waste from the food industry (preferably difficult to compost), such as ○ Core and shell The activating solution is preferably a liquid. This allows for easy mixing with the solid components of the composition.

[0016] In addition to alkali metal silicates, the activating solution preferably contains hydroxides, and particularly preferably contains potassium hydroxide and / or sodium hydroxide and / or rubidium hydroxide and / or cesium hydroxide.

[0017] Furthermore, it is preferably specified that the alkali metal silicate is sodium silicate and / or potassium silicate. Alternatively or additionally, the alkali metal silicate may also include lithium silicate. The solid components of the compositions according to the invention can be readily alkali-activated using liquid forms of sodium silicate, potassium silicate, and / or lithium silicate (water glass). Although lithium water glass has the best reactivity, it is more expensive than sodium water glass and potassium water glass.

[0018] Preferably, the activation solution comprises potassium hydroxide and potassium silicate. The activation solution comprising potassium hydroxide and potassium silicate preferably does not contain other hydroxides and silicates. Furthermore, it is preferably specified that the activation solution comprises sodium hydroxide and sodium silicate. The activation solution comprising sodium hydroxide and sodium silicate preferably does not contain other hydroxides and silicates.

[0019] Preferably, the activating solution contains between 20% and 90% by mass, particularly preferably between 40% and 80%, and especially about 50% to 70% alkali metal silicates. Within these ranges, the strength of the final product (i.e., the component) is the highest.

[0020] Furthermore, it is preferably specified that the base material comprises clay, and the mass fraction of the clay is preferably 200% to 400% of the mass fraction of the clay, particularly preferably 250% to 350%. This ratio between clay and clay provides a favorable ratio between the reactive material and the filler, enabling the production of stable components.

[0021] To further improve the strength of the formed component, it is preferably specified that the ratio of the mass of the activating liquid to the mass of the clay is between 1.1 and 1.6, and particularly preferably between 1.25 and 1.35. Furthermore, such a ratio has a positive impact on the flowability and processability of the composition.

[0022] Furthermore, it is preferably specified that the ratio of the mass of the activating liquid to the mass of the solid component is between 0.2 and 0.4, and particularly preferably between 0.25 and 0.35. Such a ratio achieves good kneadability of the composition, which improves its processability when shaped into components.

[0023] In a preferred embodiment, the clay is specified to comprise metakaolin. Particularly preferred is metakaolin. Metakaolin has been proven and is very suitable for use in geopolymers.

[0024] The activating solution preferably contains water (H2O). It is particularly useful for improving the miscibility and binding of the individual components of the composition during mixing.

[0025] Based on the total mass of the composition, the composition preferably comprises 50% to 70% by mass of base material, 5% to 20% by mass of clay, 5% to 20% by mass of alkali metal silicate, 0% to 10% by mass of hydroxide and 0% to 25% by mass of water.

[0026] The present invention also relates to a method for producing a component, wherein, in a first step, a mixture comprising a solid component and an activating liquid is prepared, the solid component comprising a clay and at least one base material, the activating liquid comprising more than 5% by mass of an alkali metal silicate, the base material comprising 200% to 500% by mass of the clay, and the ratio between the mass of the activating liquid and the mass of the clay being greater than 1; in a second step, the mixture is formed into a component using an extruder.

[0027] First, the compositions according to the invention are brought together and mixed to form a substantially homogeneous mixture. To remove air bubbles from the composition, it is preferably specified that the composition is subjected to vibration and / or negative pressure after mixing. The composition is then shaped into the desired form using an extruder (or press). For example, an extruder is used to form a continuous profile of a component (e.g., a brick), which is then cut at fixed intervals to form individual bricks.

[0028] After the component is formed, it is preferably specified that the component be hardened in a third step following the second step. Hardening is preferably carried out in ambient air, i.e., without heating or pressurization. This makes it particularly easy to produce components with high compressive strength (e.g., bricks). It is preferably specified that hardening is carried out at an air temperature of at least 20°C and a humidity of at least 50% (rH, relative humidity). Particularly preferred is hardening at an air temperature of 20°C to 30°C and a relative humidity of 50% to 90%, preferably 50% to 80%. Under these conditions, hardening is rapid, cost-effective, and prevents component cracking.

[0029] Preferably, the mixing in the first step of the method is carried out as follows: First, the alkali metal silicate is mixed with water. Then, the hydroxide is dissolved in the alkali metal silicate-water mixture to obtain an activated solution.

[0030] In addition, the solid components (i.e., the base materials, especially clay and sand) are mixed with the clay until a substance of substantially homogeneous solid components is formed. This step can be carried out simultaneously with the preparation of the activation solution, before or after the preparation of the activation solution.

[0031] After providing the activating liquid and solid components, the activating liquid is added to the solid components and mixed until a substantially homogeneous and kneadable substance is formed. This substance is then used to produce components.

[0032] Alternatively, the components of the composition can be mixed together in different orders to obtain a substantially homogeneous substance. Attached Figure Description

[0033] The present invention will now be described in more detail with reference to exemplary embodiments schematically illustrated in the accompanying drawings. Figure 1 A schematic diagram of the method according to the invention is shown, which is substantially the same for producing all three examples. Detailed Implementation

[0034] Figure 1 The diagram schematically illustrates the sequence of the method according to the invention for producing the composition according to the invention. In section 1, an activating liquid is prepared. In section 2, a solid component is prepared. The mixing of the activating liquid (section 1) and the mixing of the solid component (section 2) can be carried out simultaneously or at different times, for example, one after the other. The activating liquid from section 1 and the solid component from section 2 are then combined in section 3. In section 4, the composition formed in section 3 is molded into a molded article, for example using a die or extruder. The molded article is then hardened in section 5.

[0035] The following describes three examples of this method.

[0036] Example 1 In section 1, 1.535 kg of potassium silicate is mixed with 0.768 kg of water. Then, 1.075 kg of potassium hydroxide is dissolved in the potassium silicate-water mixture to obtain an activation solution. The activation solution contains approximately 45% by mass of alkali metal silicates in the form of potassium silicate.

[0037] Furthermore, in the second section 2, the solid components (i.e., 2.205 kg metakaolin, 5.066 kg clay, and 5.066 kg quartz sand) are mixed together, for example, in a forced mixer, until a substantially homogeneous material is formed. The mass of the clay and sand (quartz sand) is approximately 460% of the mass of the metakaolin-clay mixture.

[0038] Then, in section 3, the activating liquid is added to the solid components and mixed until a substantially homogeneous and kneadable substance is formed (first method step). The ratio between the mass of the activating liquid (3.378 kg) and the mass of the metakaolin-form metaclay (2.205 kg) is approximately 1.53. The ratio between the mass of the activating liquid (3.378 kg) and the mass of the solid components (12.337 kg) is approximately 0.27.

[0039] This kneadable material can now be used to produce components. In this example, in section 4 (second method step), the material is fed into the feeder of an extruder. In the vacuum chamber of the extruder, the material is vented and extruded into strips through the nozzle of the extruder, and then cut into smaller components, such as bricks, after leaving the extruder.

[0040] In section 5 (third method step), the resulting component is finally hardened at at least 20°C and at least 50% rH (relative humidity). The compressive strength is measured after 28 days and is approximately 60 MPa.

[0041] Example 2 In section 1, 1.520 kg of sodium silicate is mixed with 0.520 kg of water. Then, 0.200 kg of sodium hydroxide is dissolved in the sodium silicate-water mixture to obtain an activation solution. The activation solution contains approximately 68% by mass of alkali metal silicates in the form of sodium silicate.

[0042] Furthermore, in the second section 2, the solid components (i.e., 1,800 kg metakaolin, 3,600 kg clay, and 0,900 kg silica sand (particle size 0.1 to 0.2 mm)) are mixed together, for example, in a forced mixer, until a substantially homogeneous material is formed. The mass of the clay and sand (silica sand) is approximately 270% of the mass of the metakaolin-clay mixture.

[0043] Then, in section 3, the activating liquid is added to the solid components and mixed until a substantially homogeneous and kneadable substance is formed (first method step). The ratio between the mass of the activating liquid (2.240 kg) and the mass of the metakaolin clay (1.800 kg) is approximately 1.24. The ratio between the mass of the activating liquid (2.240 kg) and the mass of the solid components (6.300 kg) is approximately 0.36.

[0044] This kneadable material can now be used to produce components. In this example, in section 4 (second method step), the material is fed into the feeder of an extruder. In the vacuum chamber of the extruder, the material is vented and extruded through the nozzle of the extruder into strips, which are then cut into smaller components, such as bricks.

[0045] In section 5 (third method step), the resulting component is finally hardened at at least 20°C and at at least 50% rH (relative humidity). The compressive strength is measured after 28 days and is approximately 55 MPa.

[0046] Example 3 In the first section 1, 3.700 kg of potassium silicate is mixed with 0.700 kg of water. Then, 0.500 kg of potassium hydroxide is dissolved in the potassium silicate-water mixture to obtain an activation solution. The activation solution contains approximately 76% by mass of alkali metal silicates in the form of potassium silicate.

[0047] Furthermore, in the second section 2, the solid components (i.e., 4,500 kg of metakaolin and 13,500 kg of quartz sand (particle size 0.1 to 0.2 mm)) are mixed together, for example, in a forced mixer, until a substantially homogeneous material is formed. The mass of the quartz sand is approximately 300% of the mass of the metakaolin-clay mixture.

[0048] Then, in section 3, the activating liquid is added to the solid components and mixed until a substantially homogeneous and kneadable material is formed (first method step). The ratio between the mass of the activating liquid (4.900 kg) and the mass of the metakaolin clay (4.500 kg) is approximately 1.09. The ratio between the mass of the activating liquid (4.900 kg) and the mass of the solid components (18.000 kg) is approximately 0.27.

[0049] This kneadable material can now be used to produce components. In this example, in section 4 (second method step), the material is quantified into molded articles, such as bricks, and compacted and degassed on a vibrating table.

[0050] In section 5 (third method step), the resulting component is finally hardened at at least 20°C and at least 50% rH (relative humidity). The compressive strength is measured after 28 days and is approximately 65 MPa.

Claims

1. A composition for producing a structural member, comprising a solid component and an activating liquid, the solid component comprising at least one base material and a metakaolin, characterized in that, The activation liquid comprises more than 5% by mass of alkali metal silicate, the mass of the base material is 200% to 500% of the mass of the metakaolin, the ratio between the mass of the activation liquid and the mass of the metakaolin is greater than 1.

2. The composition of claim 1, wherein, The base material comprises sand, wherein the mass of the sand is preferably 10% to 500% of the mass of the metakaolin.

3. The composition according to claim 1 or 2, characterized in that, The alkali metal silicate is sodium silicate and / or potassium silicate.

4. The composition according to claim 1, 2 or 3, characterized in that, The activation liquid comprises between 20% and 90% by mass, particularly preferably between 30% and 50% by mass, of alkali metal silicate.

5. The composition according to any one of claims 1 to 4, characterized in that, The base material comprises clay, the mass fraction of the clay is preferably 200% to 400% of the mass fraction of the metakaolin.

6. The composition according to any one of claims 1 to 5, characterized in that, The ratio between the mass of the activation liquid and the mass of the metakaolin is between 1.1 and 1.6, particularly preferably between 1.25 and 1.

35.

7. The composition according to any one of claims 1 to 6, characterized in that, The metakaolin comprises metakaolin.

8. A method for producing a component, wherein In a first step, a mixture of a composition comprising a solid component and an activation liquid is prepared, the solid component comprising at least one base material and metakaolin, characterized in that the activation liquid comprises more than 5% by mass of alkali metal silicate, the mass of the base material is 200% to 500% of the mass of the metakaolin, the ratio between the mass of the activation liquid and the mass of the metakaolin is greater than 1, and in a second step, the mixture is formed into a component using an extruder.

9. The method of claim 8, wherein, The component is hardened in a third step after the second step. The base material comprises sand, wherein the mass of the sand is preferably 10% to 500% of the mass of the metakaolin. The alkali metal silicate is sodium silicate and / or potassium silicate. The activation liquid comprises between 20% and 90% by mass, particularly preferably between 30% and 50% by mass, of alkali metal silicate. The base material comprises clay, the mass fraction of the clay is preferably 200% to 400% of the mass fraction of the metakaolin. The ratio between the mass of the activation liquid and the mass of the metakaolin is between 1.1 and 1.6, particularly preferably between 1.25 and 1.

35. The metakaolin comprises metakaolin. In a first step, a mixture of a composition comprising a solid component and an activation liquid is prepared, the solid component comprising at least one base material and metakaolin, characterized in that the activation liquid comprises more than 5% by mass of alkali metal silicate, the mass of the base material is 200% to 500% of the mass of the metakaolin, the ratio between the mass of the activation liquid and the mass of the metakaolin is greater than 1, and in a second step, the mixture is formed into a component using an extruder. The component is hardened in a third step after the second step.

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