JP2008030974A - Carbonated solid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbonated solid in which a material other than an uncarbonated Ca-containing material is blended by a suitable amount as the raw material, thus the material is also made utilizable as the raw material. <P>SOLUTION: The carbonated solid is obtained by solidifying a raw material essentially consisting of a particulate uncarbonated Ca-containing material by carbonation reaction, and comprises a material originated from a living thing as part of the raw material. Since the material originated from a living thing is used as a part of the raw material, and it can be stably held, the material originated from a living thing disposed of as waste originally is made utilizable as the raw material, and further, the surface properties, components and internal structure of the carbonated solid according to the properties, form and constituents of the material originated from a living thing to be used can be obtained, various additional functions can be imparted to the carbonated solid as well. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention can be obtained by bringing a raw material mainly composed of powdered uncarbonated Ca-containing material such as steel slag into contact with carbon dioxide gas and solidifying calcium carbonate produced by a carbonation reaction as a main binder. It relates to a carbonate solidified body.

As one of the methods for making steel slag (slag generated in the steel manufacturing process), carbon dioxide using powdered slag using uncarbonated Ca (CaO and / or Ca (OH) ₂ ) contained therein A method for obtaining a carbonated solidified body (stone) by solidification is known (for example, Patent Documents 1 and 2). In this method, for example, powdery slag to which moisture is added is filled into a mold, and carbonation gas is blown into the slag filling layer to cause a carbonation reaction in uncarbonated Ca contained in the slag. The slag filling layer is consolidated using calcium carbonate produced by the crystallization reaction as a main binder to obtain a blocked carbonated solidified body. The carbonic acid solidified body thus obtained is used as a material for underwater sedimentation for algae reefs and fish reefs in Patent Document 1, and as a material for sedimentation of freshwater system water bodies such as rivers in Patent Document 2, respectively. Is.

This carbonated solid production technology is very useful from the viewpoint of resource recycling because slag and other waste materials containing CaO can be used as raw materials. In addition, when the carbonated solid produced is used as a material for submerging in water, it is found that it has superior performance compared to concrete products in terms of providing a favorable environment for seaweed growth and aquatic life. ing.
Japanese Patent No. 3175694 Japanese Patent No. 3175710

However, since the conventional manufacturing technology of carbonated solids is mainly intended to use uncarbonated Ca-containing material itself, the carbonated solidified material is blended with other raw materials in the uncarbonated Ca-containing material. There has been little research on the production of such other raw materials. Patent Documents 1 and 2 show that a powdery additive is added to an uncarbonated Ca-containing material. This is an iron source or soluble silica source for eluting iron and silicic acid into water. However, it is substantially the same as using a non-carbonated Ca-containing material as a raw material.
Therefore, an object of the present invention is a carbonate solidified body obtained by solidifying a raw material mainly composed of an uncarbonated Ca-containing material by a carbonation reaction, and contains an appropriate amount of a material other than the uncarbonated Ca-containing material as a raw material. Thus, an object of the present invention is to provide a carbonic acid solidified body that can also be used as a material.

In order to solve the above problems, the present invention has the following gist.
[1] A carbonate solid obtained by solidifying a raw material mainly composed of granular uncarbonated Ca-containing material by a carbonation reaction, characterized in that it includes a biological material as a part of the raw material. Carbonate solidified.
[2] The carbonate solidified body according to the above [1], wherein at least a part of the biological material is a shell.

  The carbonated solid of the present invention uses a biological material as a part of the raw material, and can stably hold it. For this reason, it has become possible to use biological materials that have been disposed of as waste (for example, incineration or landfill treatment), and depending on the properties, forms, and components of the biological materials used. Further, since the surface properties, contained components and internal structure of the carbonated solid are obtained, various additional functions can be imparted to the carbonated solid.

The carbonate solidified body of the present invention is a carbonate solidified body obtained by solidifying a raw material mainly composed of granular uncarbonated Ca-containing material by a carbonation reaction, and a biological material is used as a part of the raw material. Is included.
The uncarbonated Ca-containing material as the main raw material of the carbonated solid body may be any material as long as uncarbonated Ca (CaO and / or Ca (OH) ₂ ) is included as at least a part of the composition of the solid particles. In addition to CaO and Ca (OH) ₂ as minerals, 2CaO · SiO ₂ , 3CaO · SiO ₂ , glass and the like which are present in solid particles as part of the composition are also included.

  The uncarbonated Ca-containing material is not particularly limited as long as it contains uncarbonated Ca as at least a part of the composition as described above, but the content of uncarbonated Ca is high, and recycling of resources is also possible. Concrete such as steel slag (slag generated in the steel manufacturing process), waste concrete material and the like is particularly preferable in that it can be achieved. Generally, the CaO concentration of steel slag is about 13 to 55 mass%, the CaO concentration of concrete (for example, waste concrete) is about 5 to 15 mass% (CaO concentration in cement: 50 to 60 mass%), and these Can be said to be extremely suitable as an uncarbonated Ca-containing material. Therefore, it is preferable that the non-carbonated Ca-containing material is at least partly, desirably steel slag and / or concrete.

Steel slag includes blast furnace slag, blast furnace granulated slag, etc., decarburization slag, dephosphorization slag, desulfurization slag, desiliconization slag, casting slag generated in processes such as pretreatment, converter and casting. Such as steelmaking slag, ore reduction slag, electric furnace slag, etc. can be mentioned, but is not limited to these, and two or more slags can be mixed and used.
In addition, iron and steel slag contains a considerable amount of iron (iron such as granular iron). If such slag is used as it is, the CaO concentration in the raw material is reduced by this amount of iron. It is preferable to use slag that has undergone a metal (iron) recovery process.

Moreover, as concrete, the waste concrete etc. which were produced by the demolition of a building or a civil engineering structure etc. can be used, for example.
Examples of the non-carbonated Ca-containing material include mortar, glass, alumina cement, CaO-containing refractories, in addition to the steel slag and concrete, and one or more of these may be used alone or in combination. It can also be used by mixing with steel slag and / or concrete.
These materials are crushed into fine particles as necessary and used as raw materials.

The particle size of the uncarbonated Ca-containing material is not particularly limited, but it is preferable that the particle size is fine to some extent in order to secure the contact area with CO ₂ and increase the reactivity. In addition, if the particle size of the uncarbonated Ca-containing material is too large, Ca that cannot be carbonated remains inside the raw material particles, so that the raw material particles in the produced carbonized solidified body expand and collapse, causing cracks and the like. In some cases. In view of the above, the uncarbonated Ca-containing material has a particle size of substantially 10 mm or less, more desirably 5 mm or less, and particularly desirably 3 mm or less, substantially (i.e., excluding unavoidably large solid particles included). preferable.

If the biological material mix | blended with a non-carbonated Ca containing material is a biological material, there will be no restriction | limiting in particular. Examples of biological materials include shells, dead corals, bones, wood, cereal shells, organic sediments, compost, pruning materials and leaves of plants, sawdust, plant or animal fibers (yarns, woven fabrics, etc.), foods or beverages Examples include raw rice squeeze (for example, sugar cane and fruit squeeze), and one or more of these can be used.
Since these biological materials are stably held as a part of the solidified carbonic acid, they can be used as raw materials for the solidified carbonic acid even if they are originally discarded as waste. can do. Furthermore, since the surface properties, components, and internal structure of the carbonated solid according to the properties, forms, and constituents of the biological material used can be obtained, various additional functions can be imparted to the carbonated solid. it can.

For example, when the biological material is shells, dead corals, and wood (wood chips, etc.), the surface of the carbonate solidified body is provided with irregularities and roughness, and the carbonized solidified body is used as a biological settlement base or fishing reef. When deposited in water, the adhesion of organisms such as seaweed and corals is improved. In addition, when the biological material is organic sediment, compost, etc., the component that is effective for the growth of seaweed etc. from the biological material when the carbonate solidified body is submerged as a biological settlement base or fishing reef. Elutes in water. That is, countless fine through pores exist inside the carbonized solid, and the fine through pores of the carbonized solid set in the water are filled with water, so that the active ingredient contained in organic deposits and compost Elutes into water through fine through-pores.
Furthermore, depending on the type of biological material, the internal structure of the carbonate solidified body such as the internal porosity also changes. By adjusting the type of biological material and its blending ratio, the specific gravity and active ingredients of the carbonized solidified body are adjusted. Can be freely controlled.

Even when the biological material is a solid material such as a shell or wood, there is no particular restriction on the size thereof, but if it is too large, it becomes unsuitable as a raw material for carbonated solids, and the particle size is less than 100 mm, preferably Less than about 10 mm is appropriate. Therefore, it is preferable that the biological material is crushed, pulverized or shredded to the above particle size as necessary.
Moreover, there is no special restriction | limiting in the mixing | blending rate of the biological origin material in a raw material, What is necessary is just to mix | blend in the limit which does not cause the remarkable strength fall of a carbonization solidified body, Usually, the uncarbonated Ca containing material which is a main raw material 5 to 50% by mass, preferably about 5 to 30% by mass is suitable.

In addition, you may mix | blend solid particles other than an uncarbonated Ca containing material and biological material with the limit which does not cause the remarkable strength fall of a carbonate solidified body to the carbonate solidified body of this invention. Examples of such solid particles include natural stone, sand, soluble silica, metal (for example, metallic iron, iron oxide) and the like.
The carbonate solidified body of the present invention is suitable for underwater subsidence use such as a biological settlement base and a fishing reef for growing a living organism such as seaweed and coral, but is not limited to this. Or it can be used for any application on land.

A general method for producing a carbonated solid body of the present invention is to mix a biological material into a powdery uncarbonated Ca-containing material as a main raw material, and further add an appropriate amount of water to a raw material containing other materials as necessary. Then, a raw material filled layer is formed by filling a mold or the like, and carbon dioxide gas (or a carbon dioxide-containing gas) is blown into the raw material filled layer to solidify the raw material filled layer. Usually, the water content of the raw material packed bed is 3 to 12 mass%, preferably about 5 to 10 mass%. The carbon dioxide gas passing through the raw material packed bed reacts with Ca ions eluted from the raw material particles into the surface adhering water, and CaCO ₃ precipitates on the surface of the raw material particles, which acts as a binder to solidify the raw material packed bed. proceed.
After supplying the carbon dioxide gas for a predetermined time, the solidified raw material packed layer is removed from the mold, and the solidified carbonate is taken out.

Examples of the carbon dioxide gas or carbon dioxide-containing gas used include, for example, exhaust gas from a calcined lime factory (usually around CO ₂ : 25 vol%) and furnace exhaust gas (usually CO ₂ : 6.5 vol%) that are discharged within an integrated steelworks. Before and after) is preferable, but not limited thereto. In addition, if the CO ₂ concentration in the gas is too low, there arises a problem that the processing efficiency is lowered, but other problems are not exceptional. Therefore, the CO ₂ concentration is not particularly limited, but it is preferable to set the CO ₂ concentration to 3 vol% or more for efficient treatment.

Claims (2)

  A carbonate solidified product obtained by solidifying a raw material mainly composed of granular uncarbonated Ca-containing material by a carbonation reaction, characterized by containing a biological material as a part of the raw material. body.   The carbonated solidified body according to claim 1, wherein at least a part of the biological material is a shell.