Composition for manufacturing component members

Abstract

The present invention relates to a composition for manufacturing a component, comprising a solid component containing at least one base material and metaclay, and an activating solution, wherein the activating solution contains more than 5% by mass of alkali silicate, the mass of the base material is 200% to 500% of the mass of the metaclay, and the ratio of the mass of the activating solution to the mass of the metaclay is greater than 1. The present invention further relates to a method for manufacturing a component, comprising: in a first step, manufacturing a mixture of the composition comprising a solid component containing at least one base material and metaclay, and an activating solution, wherein the activating solution contains more than 5% by mass of alkali silicate, the mass of the base material is 200% to 500% of the mass of the metaclay, and the ratio of the mass of the activating solution to the mass of the metaclay is greater than 1; and in a second step, molding the mixture into a component using an extruder.

Description

Technical Field

[0001] The present invention relates to a composition for manufacturing a component, which includes a solid component containing at least one base material and metakaolin, and an activating solution.

Background Art

[0002] Various compositions and processes for manufacturing components such as bricks and walls are known from the prior art. For example, wall stones can be cut directly from rocks, or mud bricks and clay bricks can be molded and fired to obtain sufficient strength values for wall structures.

[0003] As a well-known method for manufacturing components, there is a method of preparing a geopolymer composition and then forming the component by extruding it. A special composition or process for manufacturing geopolymer components is described in European Patent No. 2727894. In this process, metaalumina, clay, and an activating solution are first mixed with each other, then the resulting composition is extruded, and finally the formed component is dried. Clay having a mass in the range of 5% to 40% by mass of the mass of the metakaolin is added to the composition used. The ratio of the activating solution to the solid components, particularly metakaolin and clay, is 0.25 to 0.85. The activating solution also contains sodium or potassium silicate at a ratio of 0 to 20% by mass. Using this process, components having a strength of up to about 30 MPa can be manufactured.

[0004] The disadvantage of known processes or compositions for manufacturing geopolymer components is that the strength is significantly lower compared to, for example, the strength achievable with conventional fired bricks.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, an object of the present invention is to provide a composition that enables a finished component with higher strength. [Means for solving the problem]

[0006] According to the present invention, in the composition of the type described at the beginning, the activating solution contains an alkali silicate in a proportion of more than 5% by mass, the mass of the base material is 200% to 500% of the mass of the metaclay, and the ratio of the mass of the activating solution to the mass of the metaclay is greater than 1.

[0007] According to the present invention, the solid component therefore includes metaclay. The solid component also preferably includes a base material consisting of either clay (only) or sand (only), or clay and sand. Furthermore, the mass of the clay and / or sand is 200% to 500% of the mass of the metaclay. If the base material consists only of clay and no sand, the mass of the clay is 200% to 500% of the mass of the metaclay. If the base material consists only of sand and no clay, the mass of the sand is 200% to 500% of the mass of the metaclay. Preferably, the base material includes clay and sand, or consists of clay and sand. The ratio of the mass of clay to the mass of sand is particularly preferably 0.2:1 to 4:1, more preferably 0.5:1 to 2:1, particularly preferably 0.8:1 to 1.2:1, and particularly preferably about 1:1.

[0008] The compositions can be mixed to form a substantially homogeneous mass, which can then be used to form components. The mass provided by the composition is also preferably kneadable to ensure good moldability. The composition is preferably free of components other than those explicitly listed, particularly the base material, metaclay, and activation solution, with the exception of potentially small impurities.

[0009] Clay (or clay minerals) contains layered silicates, which have a layered crystalline structure composed of silicon and oxygen, as well as hydrogen and usually magnesium and aluminum. Silicate anions consist of layers of SiO4 tetrahedra connected at their corners. These include, for example, mica, chlorite, smectite, and kaolin. The clay may be dry or wet before being mixed with other components. It is preferable that the clay has not been thermally treated before being mixed with other components of the composition according to the present invention.

[0010] In the context of this invention, metaclay is understood to mean clay that has been treated at high temperatures (approximately 500°C to 900°C) to remove bound water and alter its structure or crystal lattice. Metaclay mainly consists of reactive silicon dioxide and aluminum oxide. A well-known example is metakaolin, which is kaolin treated at approximately 550°C to 850°C.

[0011] By mixing the composition according to the present invention, a geopolymer is formed by a chemical reaction between the solid component, particularly the metaclay, and the activation solution. The geopolymer according to the present invention exhibits high compressive strength (e.g., about 60 MPa (N / mm²)) after a curing time (about 14 days) following the molding of the constituent members. 2 It has the characteristic of having (possibly) a heat or pressure during curing. Furthermore, it is not necessary to actively apply heat or pressure during curing. Therefore, curing can be performed in ambient air. It is preferable to perform curing at an air temperature of at least 20°C and a humidity (rH; relative humidity) of at least 50%. It is particularly preferable to perform curing at an air temperature of 20°C to 30°C and a relative humidity of 50% to 90%, preferably 50% to 80%.

[0012] The base material contains sand, preferably quartz sand, and the mass of the sand is preferably 10% to 500%, and particularly preferably 100% to 300%, of the mass of the metaclay. This further increases the strength of the composition when dry. The solid components, especially the clay and metaclay, and possibly the sand, are preferably in powder form when mixed with the activation solution. The sand may be dry or wet before being mixed with the other components.

[0013] Sand, especially quartz sand, has a particle size of 0.05 to 0.5 mm, particularly preferably 0.1 to 0.2 mm. It is preferable that it has

[0014] The water content of individual components, particularly clay and / or sand, can be measured before or during the production of the composition, and the composition's formulation can be adjusted as needed, for example, by adding more or less water to the activation solution.

[0015] The base material may be one or more of the following materials, or may contain them: ■ Wood (material), for example: ○ Single-ply strip ○ Remaining plywood ○ Wood shavings (preferably 100-200 mm in length, 10-50 mm in width, and 0.6-1.5 mm in thickness) ○ Wood chips (preferably 0.5-3 cm in length) ○ Wood chips, wood sticks, wood veneer ■ Plastic (leftover material), for example: ○ Finely ground plastic powder (preferably with a particle size of 0.15 to 0.50 mm) ○ Crushed or extruded plastic granules (preferably with a particle size of 1-5 mm) ○ Shredded plastic pieces ■ Recycled materials, for example: ○ Plastic ones ○ Building materials, ceramics, road surfaces, and / or metals ○ From mineral-based construction waste (preferably crushed to a particle size of 0.1 to 50 mm) ■ Light mineral fillers, such as: ○ Glass spheres ○ Polystyrene (e.g., expanded polystyrene EPS ("styrofoam") or extruded polystyrene XPS) ○ PU foam (waste) ○ Fillers for lightweight materials such as foam, expanded clay, expanded glass, expanded slate, expanded glass, perlite, vermiculite, cellulose fibers or flakes, and expanded plastics ■ Glass (waste), such as: ○ Crushed glass ○ Optical function elements such as glass spheres as reflectors ■ Fibers, such as: ○ Mineral wool, glass fibers, carbon fibers, wood wool, plant fibers, straw, hair ■ Waste from the food industry (preferably those difficult to compost), such as: ○ Seeds and husks

[0016] The activating solution is preferably liquid. This enables easy mixing with the solid part of the composition.

[0017] In addition to the alkali silicate, the activating solution preferably contains hydroxides, particularly preferably potassium hydroxide and / or sodium hydroxide, and / or rubidium hydroxide and / or cesium hydroxide.

[0018] Also, the alkali silicate is preferably sodium silicate and / or potassium silicate. Alternatively or additionally, the alkali silicate may also contain lithium silicate. The use of sodium silicate, potassium silicate and / or lithium silicate (water glass) in liquid form enables easy alkali activation of the solid components of the composition according to the invention. Lithium water glass has the best reactivity but is more expensive than sodium water glass and potassium water glass.

[0019] The activating solution is preferably made to contain potassium hydroxide and potassium silicate. The activating solution containing potassium hydroxide and potassium silicate preferably does not contain other hydroxides and other silicates. Also, the activating solution is preferably made to contain sodium hydroxide and sodium silicate. The activating solution containing sodium hydroxide and sodium silicate preferably does not contain other hydroxides and other silicates.

[0020] The activating solution preferably has an alkali silicate of 20% to 90% by mass, particularly preferably 40% to 80%, particularly about 50% to 70% by mass. Within these ranges, the strength of the final product that can be achieved, i.e., the component member, is maximized.

[0021] Also, the base material has clay, and the mass fraction of the clay is preferably 200% to 400%, particularly preferably 250% to 350% of the mass fraction of the metakaolin. This ratio of clay to metakaolin provides a suitable ratio of reactive material to filler for enabling the production of stable component members.

[0022] To further increase the strength of the formed component member, the ratio of the mass of the activating solution to the mass of the metakaolin is preferably 1.1 to 1.6, particularly preferably 1.25 to 1.35. In addition, this ratio has a positive effect on the fluidity of the composition, and thus favorably affects the ease of processing of the composition.

[0023] Also, the ratio of the mass of the activating solution to the mass of the solid component is preferably 0.2 to 0.4, particularly preferably 0.25 to 0.35. With this ratio, a composition with good kneadability can be obtained, thereby improving the workability into component members.

[0024] In a preferred embodiment, the metakaolin is made to contain metakaolin. It is particularly preferred that the metakaolin is metakaolin. Metakaolin is very suitable for use in geopolymers and has a track record.

[0025] The activation solution preferably contains water (H2O). This is particularly useful in improving the miscibility and bonding of the individual components of the composition during mixing.

[0026] The composition preferably contains, based on the total mass of the composition, 50% to 70% by mass of a base material, 5% to 20% by mass of metaclay, 5% to 20% by mass of alkali silicate, 0% to 10% by mass of hydroxide, and 0% to 25% by mass of water.

[0027] The present invention further relates to a method for manufacturing a component, the method comprising: in the first step, a mixture of the composition comprising a solid component having at least one base material and metaclay, and an activating solution, wherein the activating solution contains more than 5% by mass of alkali silicate, the mass of the base material is 200% to 500% of the mass of the metaclay, and the ratio of the mass of the activating solution to the mass of the metaclay is greater than 1; and in the second step, the mixture is molded into a component using an extruder.

[0028] The composition according to the present invention is first prepared and mixed to create a substantially homogeneous mixture. To remove air bubbles from the composition, it is preferable to subject the composition to vibration and / or negative pressure after mixing. The composition is then formed into a desired shape using an extruder (or extrusion press). For example, an extruder is used to form a brick-like component with an infinitely long profile, which is then cut at regular intervals to form individual bricks.

[0029] After forming the components, it is preferable to cure the components in a third step following the second step. Curing is preferably carried out in ambient air, i.e., without applying heat or pressure. This makes it particularly easy to manufacture components such as bricks that also have high compressive strength. Curing is preferably carried out at an air temperature of at least 20°C and a humidity (rH; relative humidity) of at least 50%. It is particularly preferable to carry out curing 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, curing is rapid, cost-effective, and cracking of the components is avoided.

[0030] The mixing in the first step of the process is preferably carried out as follows: First, the alkali silicate is mixed with water. Then, the hydroxide is dissolved in the alkali silicate-water mixture to obtain an activated solution.

[0031] Furthermore, the solid components, i.e., the base materials, particularly clay and sand and metaclay, are mixed until a substantially homogeneous mass of solid components is formed. This step may be performed simultaneously with the preparation of the activation solution, or after or before the preparation of the activation solution.

[0032] After preparing the activation solution and solid components, the activation solution is added to the solid components and mixed until a substantially homogeneous, kneadable mass is formed. This mass can then be used to manufacture the components.

[0033] Alternatively, to obtain a substantially homogeneous mass, the individual components of the composition may be mixed with each other in a different order. [Brief explanation of the drawing]

[0034] The present invention will be described in detail below using exemplary embodiments schematically shown in the drawings. [Figure 1] Figure 1 shows a schematic diagram of the method according to the present invention, which is essentially the same for all manufacturing processes of the three embodiments. [Modes for carrying out the invention]

[0035] Figure 1 schematically shows a flow of a method for producing a composition according to the present invention. In Section 1, an activation solution is prepared. In Section 2, the solid components are prepared. The mixing of the activation solution (Section 1) and the solid components (Section 2) can be done simultaneously or at different times, for example, sequentially. The activation solution from Section 1 and the solid components from Section 2 are then combined in Section 3. In Section 4, a molded product is formed from the composition formed in Section 3, for example, using a mold or extruder. The molded product is then cured in Section 5.

[0036] Three examples of this process are described below.

[0037] Example 1 In Section 1, 1.535 kg of potassium silicate was mixed with 0.768 kg of water. Then, 1.075 kg of potassium hydroxide was dissolved in the potassium silicate-water mixture to obtain an activated solution. This activated solution contained approximately 45% by mass of alkali silicate in the form of potassium silicate.

[0038] Furthermore, in Section 2, the solid components, namely 2.205 kg of metakaolin, 5.066 kg of clay, and 5.066 kg of quartz sand, were mixed, for example, in a forced mixer, until a substantially homogeneous mass was produced. The mass of the clay and sand (quartz sand) was approximately 460% of the mass of the metaclay in the form of metakaolin.

[0039] Next, in Section 3, the activation solution was added to the solid component and mixed until a substantially homogeneous, kneadable mass was formed (First Process Step). The ratio of the mass of the activation solution (3.378 kg) to the mass of the metaclay in the form of metakaolin (2.205 kg) was approximately 1.53. The ratio of the mass of the activation solution (3.378 kg) to the mass of the solid component (12.337 kg) was approximately 0.27.

[0040] This kneadable mass was then made available for use in manufacturing components. In this embodiment, in Section 4, the mass was fed into the feed section of the extruder (Second Process Step). The mass was degassed in the vacuum chamber of the extruder, the strand was extruded through the extruder's die, and after exiting the extruder, it was cut into small components such as bricks.

[0041] The resulting components were then cured in Section 5 at a temperature of at least 20°C and at least 50% rH (relative humidity) (third process step). After 28 days, the compressive strength was measured to be approximately 60 MPa.

[0042] Example 2 In Section 1, 1.520 kg of sodium silicate was mixed with 0.520 kg of water. Then, 0.200 kg of sodium hydroxide was dissolved in the sodium silicate-water mixture to obtain an activated solution. This activated solution contained approximately 68% by mass of alkali silicate in the form of sodium silicate.

[0043] Furthermore, in Section 2, the solid components, namely 1,800 kg of metakaolin, 3,600 kg of clay, and 0,900 kg of quartz sand (particle size 0.1-0.2 mm), were mixed, for example, in a forced mixer, until a substantially homogeneous mass was produced. The mass of the clay and sand (quartz sand) was approximately 270% of the mass of the metaclay in the form of metakaolin.

[0044] Next, in Section 3, the activation solution was added to the solid components and mixed until a substantially homogeneous, kneadable mass was formed (First Process Step). The ratio of the mass of the activation solution (2.240 kg) to the mass of the metaclay in the form of metakaolin (1.800 kg) was approximately 1.24. The ratio of the mass of the activation solution (2.240 kg) to the mass of the solid components (6.300 kg) was approximately 0.36.

[0045] This kneadable mass was then ready for use in the manufacture of components. In this embodiment, in Section 4, the mass was fed into the feed section of the extruder (Second Process Step). The mass was degassed in the vacuum chamber of the extruder, the strand was extruded through the extruder's die, and after exiting the extruder, it was cut into small components such as bricks.

[0046] The resulting components were then cured in Section 5 at a temperature of at least 20°C and at least 50% rH (relative humidity) (third process step). After 28 days, the compressive strength was measured to be approximately 55 MPa.

[0047] Example 3 In Section 1, 3.700 kg of potassium silicate was mixed with 0.700 kg of water. Then, 0.500 kg of potassium hydroxide was dissolved in the potassium silicate-water mixture to obtain an activated solution. This activated solution contained approximately 76% by mass of alkali silicate in the form of potassium silicate.

[0048] Furthermore, in Section 2, the solid portion, namely 4,500 kg of metakaolin and 13,500 kg of quartz sand (particle size 0.1-0.2 mm), was mixed, for example, in a forced mixer until a substantially homogeneous mass was produced. The mass of the quartz sand was approximately 300% of the mass of the metaclay in the form of metakaolin.

[0049] Next, in Section 3, the activation solution was added to the solid portion and mixed until a substantially homogeneous, kneadable mass was formed (First Process Step). The ratio of the mass of the activation solution (4.900 kg) to the mass of the metaclay in the form of metakaolin (4.500 kg) was approximately 1.09. The ratio of the mass of the activation solution (4.900 kg) to the mass of the solid component (18.000 kg) was approximately 0.27.

[0050] This kneadable mass is now ready for use in the manufacture of components. In this embodiment, in Section 4, the mass is weighed and placed into, for example, a mold for bricks, and compressed and degassed on a vibrating table (Second Process Step).

[0051] The resulting components were then cured in Section 5 at a temperature of at least 20°C and at least 50% rH (relative humidity) (third process step). After 28 days, the compressive strength was measured to be approximately 65 MPa.

Claims

1. A composition for manufacturing a component, comprising a solid component containing at least one base material and metaclay, and an activating solution, wherein the activating solution contains more than 5% by mass of alkali silicate, the mass of the base material is 200% to 500% of the mass of the metaclay, and the ratio of the mass of the activating solution to the mass of the metaclay is greater than 1.

2. The composition according to claim 1, wherein the base material contains sand, and the mass of the sand is preferably 10% to 500% of the mass of the metaclay.

3. The composition according to claim 1 or claim 2, wherein the alkali silicate is sodium silicate and / or potassium silicate.

4. The composition according to any one of claims 1 to 3, wherein the activation solution contains 20% to 90% by mass, particularly preferably 30% to 50% by mass, of the alkali silicate.

5. The composition according to any one of claims 1 to 4, wherein the base material contains clay, and the mass fraction of the clay is preferably 200% to 400% of the mass fraction of the metaclay.

6. The composition according to any one of claims 1 to 5, wherein the ratio of the mass of the activating solution to the mass of the metaclay is 1.1 to 1.6, particularly preferably 1.25 to 1.

35.

7. The composition according to any one of claims 1 to 6, wherein the metaclay comprises metakaolin.

8. A method for manufacturing a component, In the first step, a mixture of the composition is produced, comprising a solid component having at least one base material and metaclay, and an activating solution, wherein the activating solution contains more than 5% by mass of alkali silicate, the mass of the base material is 200% to 500% of the mass of the metaclay, and the ratio of the mass of the activating solution to the mass of the metaclay is greater than 1. A method comprising, in the second step, molding the mixture into constituent members using an extruder.

9. The method according to claim 8, wherein in a third step following the second step, the constituent members are hardened.

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