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JP-7857365-B2 - Method for producing a carbonate hardened product, a carbonate hardened product, granulated aggregate made from a carbonate hardened product, and a concrete composition using the same.

JP7857365B2JP 7857365 B2JP7857365 B2JP 7857365B2JP-7857365-B2

Inventors

  • 上田 陽一
  • 横光 優
  • 野田 謙二
  • 丸屋 英二

Assignees

  • ＵＢＥ三菱セメント株式会社

Dates

Publication Date
20260512
Application Date
20240919

Claims (18)

  1. A method for producing a carbonate cured product, A carbonation step to obtain a composition containing carbon oxide by bringing a raw material containing a basic compound containing CaO and water into contact with a CO2- containing gas while stirring, The process includes a granulation step of obtaining a carbonate hardened product by stirring and granulating a mixture containing the aforementioned carbon oxide and an additive, The above raw material comprises 15 parts by mass or more of CaO and 30 parts by mass or more and 80 parts by mass or less of water per 100 parts by mass of dry weight, and is a method for producing a carbonate cured product.
  2. The method for producing a carbonate cured product according to claim 1, wherein, in the granulation step, the content of the composition containing the carbon dioxide is 35 to 70 parts by dry mass and the content of the additive is 30 to 65 parts by dry mass per 100 parts by dry mass of the mixture.
  3. A method for producing a carbonate cured product according to claim 1 or 2, wherein the composition containing the carbon oxide contains Ca(OH) 2 .
  4. A method for producing a carbonate hardened product according to claim 1 or 2, wherein the raw materials include at least one selected from the group consisting of lime calcination dust, cement clinker dust, and by-product slaked lime.
  5. A method for producing a carbonate cured product according to claim 1 or 2, wherein in the carbonation step, the time during which the raw material and the CO2- containing gas are in contact is 3 to 90 minutes.
  6. The method for producing a carbonate cured product according to claim 1 or 2, wherein in the granulation step, the amount of water is adjusted to 10 to 35 parts by mass per 100 parts by mass of the dry mass of the mixture, and the mixture is granulated while stirring.
  7. A method for producing a carbonate cured product according to claim 1 or 2, wherein the carbonation rate of the composition containing the carbon oxide is 30% by mass or more and less than 100% by mass.
  8. The method for producing a carbonate cured product according to claim 1 or 2, wherein the CO2 fixation rate in the carbonation step is 10 mol% or more.
  9. A method for producing a carbonate cured product according to claim 1 or 2, wherein the additive includes a latent hydraulic material.
  10. The method for producing a carbonate cured product according to claim 1 or 2, wherein the additive is at least one selected from the group consisting of blast furnace slag and pozzolanes.
  11. The method for producing a carbonate cured product according to claim 1 or 2, wherein the granulation step is adjusted so that the average particle size of the carbonate cured product is 0.4 mm or more.
  12. A carbonate hardened product containing carbonates and formed by granulation, The average breaking load measured in accordance with JIS Z 8841-1993 is 50 N or more. A carbonate cured product having a dry mass of 100 parts by mass, containing 10 to 60 parts by mass of CaCO3 and 5 to 20 parts by mass of SiO2 .
  13. A carbonate hardened product containing carbonates and formed by granulation, The amount of CO2 fixed relative to the dry mass of the carbonate cured product is 50 kg/t or more and less than 300 kg/t. A carbonate cured product having a dry mass of 100 parts by mass, containing 10 to 60 parts by mass of CaCO3 and 5 to 20 parts by mass of SiO2 .
  14. A carbonate hardened product containing carbonates and formed by granulation, The average breaking load measured in accordance with JIS Z 8841-1993 is 50 N or more. A cured carbonate product having a cumulative pore volume of 0.06 ml/g or more for pores with a diameter of 100 nm or less.
  15. A carbonate hardened product containing carbonates and formed by granulation, CO2 as a percentage of the dry mass of the carbonate cured product 2 The fixed amount is 50 kg/t or more and less than 300 kg/t. A cured carbonate product having a cumulative pore volume of 0.06 ml/g or more for pores with a diameter of 100 nm or less.
  16. Granulated aggregate comprising a carbonate hardened product according to any one of claims 12 to 15 .
  17. cement and Fine aggregate containing the granulated aggregate described in claim 16, Coarse aggregate and Water and, A concrete composition containing [the specified ingredient].
  18. A hardened product of the concrete composition according to claim 17.

Description

This disclosure relates to a method for producing a carbonate cured product from exhaust gas containing CO2 , a carbonate cured product, a granulated aggregate consisting of the carbonate cured product, and a concrete composition containing the granulated aggregate. Technologies for the storage and sequestration of carbon dioxide ( CO2 ) are attracting attention as we work towards realizing a carbon-neutral society. If CO2 can be fixed as carbonate and then used as a construction material such as concrete, it is expected that a large amount of CO2 can be fixed, and therefore there is a strong desire to establish a practical and versatile technology. When using carbonates as concrete materials, the appropriate mixing ratio and required properties differ depending on whether they are used as a powdered mixer or as aggregate. Since the majority of concrete components are aggregates (fine or coarse aggregates), if the carbonates can be used as aggregates, their contribution to CO2 sequestration can increase in proportion to the amount used. Furthermore, in order to promote the widespread use of such aggregates and contribute to a decarbonized society, it is desirable that they be used not only in ordinary concrete but also widely in concrete for special applications and secondary products. Regarding techniques for producing carbonates that can be used as aggregates, Patent Document 1 describes a method for producing a carbonated solidified material, characterized by granulating a water-containing, uncarbonated Ca-containing raw material in the presence of carbon dioxide, and solidifying the raw material during granulation through a carbonation reaction to obtain a carbonated solidified granule. Patent Document 2 describes calcium aluminate materials such as blast furnace slag and compositions containing calcium carbonate. Japanese Patent Publication No. 2006-188368Japanese Patent Application Publication No. 8-040762 This graph shows the relationship between the pore size of the aggregate and the cumulative pore volume.This graph shows the relationship between the pore size of the aggregate and the log differential pore volume. The following describes embodiments of this disclosure. However, these embodiments are illustrative examples for illustrating this disclosure and are not intended to limit this disclosure to the following. In the following description, "X to Y" (where X and Y are arbitrary numbers) means "X or greater and Y or less" unless otherwise specified. Unless otherwise specified, the materials exemplified herein may be used individually or in combination of two or more. In compositions such as mixtures, the content of each component refers to the total amount of any multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component exist in the composition. <Method for manufacturing hardened carbonate products> One embodiment of the method for producing a carbonate cured product in this disclosure is: A carbonation step to obtain a composition containing carbon oxide by bringing a raw material containing a basic compound containing CaO and water into contact with a CO2- containing gas while stirring, The method comprises a granulation step of obtaining a carbonate hardened product by stirring and granulating a mixture containing the carbon oxide and an additive. In a preferred embodiment, the raw materials contain 15 parts by mass or more of CaO and 30 parts by mass or more and 80 parts by mass or less of water per 100 parts by mass by dry weight. (Carbonation process) In the carbonation process, a raw material containing a basic compound containing CaO and water is brought into contact with a CO2- containing gas while being stirred to obtain a composition containing carbon oxide. The raw material in the carbonation process contains a basic compound containing calcium oxide (CaO) and water. The CaO content is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 25 parts by mass or more, per 100 parts by mass of the dry mass of the raw material. The upper limit is not limited and may be 100 parts by mass, but may be, for example, 90 parts by mass or less, 85 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less. In this specification, "dry mass of raw material" means the mass after drying the raw material at 105°C for 24 hours to remove any adhering water. Multiple basic compounds containing CaO may be present in the raw materials. Examples of basic compounds other than CaO include basic compounds (excluding CaO) that have alkaline earth metals as constituent elements, with Mg and Ca being preferred as alkaline earth metals, and Ca being particularly preferred. Examples of basic compounds having calcium (Ca) as a constituent element include calcium hydroxide (Ca(OH) ₂ ), calcium silicate ( CaSiO₃ , Ca₂SiO₄ , Ca₃