JP2006188399A - Method for production of unburned ceramic building material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method for unburned ceramic building material capable of efficiently removing volatile organic compounds (VOC) from a production raw material. <P>SOLUTION: This production method comprises pretreating with hot water, a non-alkaline production raw material containing volatile organic compounds (VOC) to remove VOC, and then blending an alkaline production raw material with the above VOC-removed raw material to obtain the unburned ceramic building material. The hot water treatment is preferably performed at a temperature of 50-105°C over 10 min, and the blowing of steam is further preferable. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a non-fired ceramic building material.

  Non-fired ceramic building materials are required to use raw materials that are inexpensive and can be supplied in large quantities to meet market demands. For this reason, it is desired to provide safe products for the living environment using natural raw materials, recycled resources, and industrial by-products. However, natural raw materials are associated with the risk of adsorption and mixing of volatile organic compounds (VOC) based on the natural environment, and contamination with fuel gas in the drying stage. On the other hand, recycling resources involve processing agents at the stage of recycling, and industrial by-products are likely to be contaminated and mixed in at the stage of production.

  According to the inventor's knowledge, when non-fired ceramic building materials such as cement-based building materials are produced without removing these contaminants, alkaline earth elements such as Ca and Mg and silicic acid hydrate have oxidation catalytic ability. In order to have, alcohol may produce insoluble partial oxidation substances, such as aldehyde, acetic acid, and formic acid. Then, alkaline earth elements and aldehyde oxides (formic acid, acetic acid, etc.) undergo a neutralization reaction in the production process at room temperature, and a salt is formed. In the production process, since water is used while being circulated, VOC and reaction product salts adhering to and adsorbing to the fine raw materials that could not be dissolved and collected in water are concentrated and circulated. Once salt is formed and mixed into the product, it decomposes little by little at room temperature to generate aldehyde. The surface of the product is thermally decomposed in the drying process, but the salt inside is in a sealed state where heat is difficult to transfer, and the saturated equilibrium state persists and the decomposition reaction does not proceed. In addition, VOCs such as unsaturated fatty acids and fats and oils form metal soap, which causes a drop in vapor pressure and is difficult to be discharged out of the system.

  The present invention has been accomplished through various investigations in order to find out a method capable of efficiently removing VOCs from manufacturing raw materials while overcoming the above-mentioned difficulties.

The present invention provides the following inventions in order to solve the above problems.
(1) When manufacturing non-fired ceramic building materials, non-alkaline production raw materials containing volatile organic compounds (VOC) are treated with hot water in advance to remove VOCs, and then the production raw materials from which VOCs have been removed are produced alkaline. A method for producing a non-fired ceramic building material comprising mixing with a raw material to produce a non-fired ceramic building material;
(2) The method for producing a non-fired ceramic building material according to (1), wherein the non-fired ceramic building material is cement-based or calcium silicate-based;
(3) Production of non-fired ceramic building materials according to (1) or (2), wherein the non-alkaline production raw material includes pulp, diatomaceous earth, zeolite, halloysite, wollastonite, sepiolite, attapulgite, vermiculite, calcium carbonate, talc or flash eye Method;
(4) The method for producing a non-fired ceramic building material according to (1) or (2), wherein the alkaline production raw material is cements and / or slaked lime;
(5) The method for producing a non-fired ceramic building material according to any one of (1) to (4), wherein the hot water treatment is performed at a temperature of 50 to 105 ° C;
(6) The method for producing a non-fired ceramic building material according to any one of (1) to (5), wherein the hot water treatment is steam blowing;
(7) Steam blowing is performed by introducing steam into the liquid from the bottom of the treatment tank and bubbling, and taking out VOCs scattered on the liquid surface out of the system. Method;
(8) The method for producing a non-fired ceramic building material according to (6) or (7), wherein the steam is saturated steam at 1 to 5 atm;
(9) When manufacturing non-fired ceramic building materials, the non-alkaline production raw material containing volatile organic compounds (VOC) is treated with hydrogen peroxide in advance to remove VOC, and then the production raw material from which VOC has been removed is made alkaline. A method for producing a non-fired ceramic building material comprising mixing with a production raw material to produce a non-fired ceramic building material;
(10) The method for producing an unfired ceramic building material according to (9), wherein the hydrogen peroxide treatment is performed in a solution containing 0.1 to 7 wt% of hydrogen peroxide;
(11) The method for producing a non-fired ceramic building material according to any one of (1) to (8), wherein 0.1 to 7 wt% of hydrogen peroxide is added during the hot water treatment;
(12) The method for producing a non-fired ceramic building material according to any one of (1) to (11), wherein the production raw material from which VOC has been removed is cooled, then mixed with an alkaline production raw material, further molded, and subjected to normal pressure curing. And (13) The production raw material from which VOC has been removed is mixed with an alkaline production raw material, then held at 50 to 90 ° C., cooled and molded, and further autoclaved (1) to (11) The manufacturing method of the non-fired ceramic industry building materials as described,
It is.

  The present invention can provide a method for producing a non-fired ceramic building material capable of efficiently removing VOC from production raw materials.

  In the present invention, when manufacturing non-fired ceramic building materials, after the non-alkaline manufacturing raw material containing VOC is preliminarily hydrothermally treated to remove VOC, the manufacturing raw material from which VOC has been removed is mixed with the alkaline manufacturing raw material. To produce non-fired ceramic building materials. As the non-fired ceramic building material, cement-based or calcium silicate-based materials are preferably used.

  Non-alkaline production raw materials containing VOC include diatomaceous earth, zeolite, halloysite, wollastonite, sepiolite, attapulgite, unexpanded vermiculite, calcium carbonate, talc or flash eye. When alkaline production raw materials represented by cements and / or slaked lime are included in the non-alkaline production raw materials, the above-mentioned reaction products are formed with silicic acid in the non-alkaline production raw materials. Although it is preferable not to contain a raw material, the various compounding materials mentioned later may be included. Various VOCs are not particularly limited.

  The hot water treatment is preferably performed at a temperature of 50 to 105 ° C. for 10 minutes or more, more preferably steam blowing. In this case, steam blowing can be performed particularly efficiently by introducing and bubbling steam into the liquid from the bottom surface of the treatment tank, and taking out VOC diffused on the liquid surface from the system. It is industrially advantageous that the steam used is a saturated steam of 1 to 5 atm. The hot water treatment is preferably performed at a solid content concentration of 5 to 40 wt%. Further, by adding 0.1 to 7 wt%, preferably 1 to 4 wt% of hydrogen peroxide during the hydrothermal treatment, the effect of the hydrothermal treatment can be further improved by the oxidizing power of hydrogen peroxide.

  Further, in the method of the present invention, after the non-alkaline production raw material containing VOC is treated with hydrogen peroxide instead of hot water treatment to remove VOC, the production raw material from which VOC has been removed is mixed with the alkaline production raw material. It is also possible to produce non-fired ceramic building materials. This hydrogen peroxide treatment is preferably carried out in a solution containing 0.1 to 7 wt% hydrogen peroxide at less than 50 ° C., for example, at room temperature.

  The production raw material from which VOC has been removed in this manner is cooled, then mixed with an alkaline production raw material, further molded, and subjected to normal pressure curing to produce a non-fired ceramic building material. By this method, a product having a relatively large bulk specific gravity (for example, about 1.0 to 2.0) can be manufactured. Alternatively, in another embodiment, the production raw material from which VOC has been removed is mixed with an alkaline production raw material, then held at 50 to 90 ° C., cooled and molded, and further autoclave-cured to obtain a relatively high specific gravity. Small (for example, about 0.70 to 1.0) and high strength products can be manufactured.

  Examples of the alkaline production raw material include cements and / or slaked lime. Examples of cements include cements such as Portland cement, blast furnace cement, and fly ash cement. You may mix | blend aggregates, such as lightweight aggregates, such as fine aggregates or coarse aggregates, such as sand and gravel, and other expanded vermiculite, and pearlite, with these alkali manufacture raw materials. Further, reinforcing fibers may be included, and examples of the reinforcing fibers include short fibers such as vinylon for improving cement adhesion, rayon for improving toughness, and polypropylene for improving hydrophobicity. These compounding materials can be appropriately selected together with other admixtures according to the purpose of the cement product to be obtained, and the compounding amounts thereof can be determined by a conventional method.

  When producing non-fired ceramic building materials according to the present invention, as described above, after VOC is removed by previously hydrothermally treating a non-alkaline production raw material to remove VOC, the production raw material from which VOC has been removed is produced alkaline. It is necessary to mix with raw materials, but molding (for example, papermaking, pressing, etc.), curing, curing, and drying itself can be performed by conventional methods. For example, non-firing ceramics that can efficiently remove VOCs such as flexible boards Building materials can be manufactured easily.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples, unless the summary is exceeded.
Example 1
A non-alkaline production raw material having the following composition was blended and kneaded.
70 parts by weight of pulp;
240 parts by weight of fly ash;
Sepiolite 15 parts by mass; and hydrous halloysite 50 parts by mass Water is mixed with this composition to a solid content concentration of 30 wt%, and steam is introduced into the liquid from the bottom of the treatment tank by introducing saturated steam at about 3 atm. Then, bubbling was performed to remove VOCs scattered on the liquid surface out of the system. Next, 650 parts by weight of Portland cement, 100 parts by weight of pearlite, 10 parts by weight of vinylon and 70 parts by weight of expanded vermiculite were blended and held at about 70 ° C. for 15 minutes, and then added to about 35 ° C. (solid content concentration: about 5 wt%) ) Cooled and formed into a board (900 × 1820 × 9.6 mm) by papermaking. Subsequently, the autoclave was cured (180 ° C., 6 hours). The obtained board had a bulk specific gravity of 0.89, a bending strength of 130 kg, and contained substantially no VOC.
Comparative Example 1
In Example 1, all components were blended and autoclave curing was performed without steam blowing. The obtained board had a bulk specific gravity of 1.17 and a bending strength of 160 kg, and VOC was detected.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the non-baking ceramic industry building material which can remove VOC efficiently from manufacturing raw material can be provided.

Claims (13)

  When manufacturing non-fired ceramic building materials, after removing non-alkaline production raw materials containing volatile organic compounds (VOC) by hydrothermal treatment in advance, VOC is removed, and then the production raw materials from which VOC has been removed are mixed with alkaline production raw materials. And manufacturing a non-fired ceramic building material.   The method for producing a non-fired ceramic building material according to claim 1, wherein the non-fired ceramic building material is cement-based or calcium silicate-based.   The method for producing a non-fired ceramic building material according to claim 1 or 2, wherein the non-alkaline production raw material includes pulp, diatomaceous earth, zeolite, halloysite, wollastonite, sepiolite, attapulgite, vermiculite, calcium carbonate, talc or flash eye.   The method for producing a non-fired ceramic building material according to claim 1 or 2, wherein the alkaline production raw material is cements and / or slaked lime.   The method for producing a non-fired ceramic building material according to any one of claims 1 to 4, wherein the hot water treatment is performed at a temperature of 50 to 105 ° C.   The method for producing a non-fired ceramic building material according to any one of claims 1 to 5, wherein the hot water treatment is steam blowing.   The method for producing a non-fired ceramic building material according to claim 6, wherein the steam blowing is performed by introducing steam into the liquid from the bottom of the treatment tank and bubbling, and taking out VOC diffused on the liquid surface from the system.   The method for producing a non-fired ceramic building material according to claim 6 or 7, wherein the steam is saturated steam at 1 to 5 atm.   When manufacturing non-fired ceramic building materials, the non-alkaline production raw material containing volatile organic compounds (VOC) is treated with hydrogen peroxide in advance to remove VOC, and then the production raw material from which VOC has been removed is treated as an alkaline production raw material. A method for producing a non-fired ceramic building material comprising mixing and producing a non-fired ceramic building material.   The method for producing a non-fired ceramic building material according to claim 9, wherein the hydrogen peroxide treatment is performed in a solution containing 0.1 to 7 wt% of hydrogen peroxide.   The method for producing a non-fired ceramic building material according to any one of claims 1 to 8, wherein 0.1 to 7 wt% of hydrogen peroxide is added during the hot water treatment.   The method for producing a non-fired ceramic building material according to any one of claims 1 to 11, wherein the production raw material from which VOC has been removed is cooled, then mixed with an alkaline production raw material, further molded, and subjected to normal pressure curing.   The non-fired ceramic building material according to any one of claims 1 to 11, wherein the production raw material from which VOC has been removed is mixed with an alkaline production raw material, then held at 50 to 90 ° C, cooled and molded, and further autoclaved. Production method.