JPH0442849A - Production of inorganic article - Google Patents

Abstract

PURPOSE:To obtain an inorganic article without problem of strength by effectively utilizing fly ash by mixing a fly ash having a specific quality with other fly ash, silica fume, cement and other adding material and then molding. CONSTITUTION:In a cement mixing using a fly ash having the quality corresponding to JIS (<=5wt.% weight loss under strong heating) as a silica source, the mixing is adopted as follows. Namely, a part of said fly ash having quality corresponding to JIS is substituted with a fly ash having >=5wt.% weight loss under strong heating according to a method other than JIS and silica fume in an amount corresponding to 1/5-1/4 of the substituted fly ash and having the quality corresponding to JIS is added. Resultant mixture is mixed with cement and other adding material as a silica source and molded to afford the objective article. An adding amount of said silica fume is restricted to 1/5-1/4 because in a case of <=1/5, improvement of strength is not expected and in a case of >=1/4, improvement of strength is not expected again in spite of the increased adding amount and becomes uneconomical.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing an inorganic product, and more particularly, to a method for manufacturing an inorganic product that makes effective use of flyanche, which is industrial waste.

[Conventional technology]

BACKGROUND ART Conventionally, products such as building materials have been widely molded using cement mixtures.

A silica source is essential for improving the strength of cement products, and silica sand and the like have been commonly used as the silica source.

By the way, SiO is also used in fly ash, which is industrial waste.
It has long been known that fly ash can be used as a silica source because it contains a large amount of fly ash, and various methods for producing inorganic products using these fly ash have been proposed, along with the effective use of industrial waste.

[Problems with conventional technology]

Incidentally, fly ash has a difference in loss on ignition depending on the conditions of the generating furnace, and if this loss on ignition is too large, there is a drawback that strength development is low.

Therefore, for products that require strength such as building materials, fly ash used as a silica source must be of a quality with a loss on ignition of 5% or less, and fly ash with a loss on ignition of more than 5%, for example, % or more, it was unsuitable as a raw material and was simply disposed of in a landfill.

[Problem to be solved by the invention]

In view of the above, this invention aims to effectively utilize fly ash, which has a high loss on ignition, and which was conventionally simply discarded.
This was done with the aim of providing a method for manufacturing inorganic products that does not have problems in terms of strength.

[Technology that led to solving the problem]

That is, the method for producing an inorganic product of the present invention uses JIS #Ik quality fly ash (ignition loss 5) as a silica source.
% or less), a part of the JIS-compliant fly ash is replaced with fly ash other than JIS-compliant quality with an ignition loss of 5% or more, and the substituted JIS-compliant fly ash is 175~1/4
This method is characterized by adding an amount of silica hume corresponding to the amount of silica, mixing this as a silica source with cement and other additives, and molding according to a conventional method.

[Effect]

The cement composition assumed in this invention is a composition using fly ash as a silica source, for example, 754772140% by weight with an ignition loss of 5% or less, 40% by weight of cement, and other raw materials such as PA reinforcing fibers and fine aggregate. This refers to a formulation in which the following ingredients are added to make a total of 100% by weight.

In this invention, a part of the above-mentioned fly ash having a loss on ignition of 5% or less is replaced with fly ash having a loss on ignition of 5% or more other than JIS-compliant quality.

This substitution reduces the quality of the silica source and the bonding strength of the cement matrix, but this reduction can be reduced by 1% of the amount of substitution.
This is supplemented by the addition of an amount of silica hume corresponding to 75 to 1/4.

The amount of silica hume added is 115 to 1/
The reason why it is limited to 4 is because if it is less than 115, no improvement in strength can be expected, and even if it is more than 1/4, no improvement in strength can be expected considering the amount of addition, which is uneconomical.

Despite the addition of fly ash, which has a large loss on ignition, the bonding strength of the cement matrix is sufficiently increased by the addition of silica hume, making it possible to mold an inorganic product with no practical problems.

In addition, in the present invention, it is desirable to cure the molded article at high temperature and high pressure in an autoclave in order to develop strength.

〔Example〕

Next, the present invention will be explained in detail.

JIS applicable fly ash 40% by weight, cement 4
2% by weight, 8% by weight of bulb fibers as reinforcing fibers, and 5410% by weight of bars as lightweight aggregate, and a part of the above 754772140% by weight was added to Table 1.
As shown in Figure 2, fly ash of non-JIS applicable quality with an ignition loss of 20 yen or more is substituted, and at the same time, 4.5 yen of the replacement amount is used.
A minute amount of silica fume was added, and a test plate having a thickness of 200 mm and a length and width of 300 mm was then molded according to a conventional method, and the plate was cured in an autoclave at 150°C.

When the bending strength of each test piece was measured, the results were shown in the lower column of Table 1.

As is clear from Table 1, it was found that the examples in which silica hume was added had the strength in the gaps and the like as compared to the basic composition.

Table 1 (Note $1 indicates the basic composition 0 bending strength in kg/cd, and % in the table indicates weight %.) [Effect] As is clear from the above, J
Even fly ash that does not fall under IS can now be effectively used as a silica source for cement products without reducing product strength.

Claims (1)

[Claims] (1) In cement formulations that use JIS quality fly ash (ignition loss 5% or less) as a silica source, a portion of the JIS quality fly ash is used as a silica source to Replaced with fly ash and substituted JIS applicable quality fly ash 1
Adding an amount of silica fume equivalent to /5 to 1/4,
A method for producing an inorganic product, which comprises mixing this as a silica source with cement and other additives and molding it according to a conventional method.