JPS5969462A - Manufacture of hardened body from coal ash - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a hardened material using coal ash emitted during coal combustion as a main raw material, and more specifically, a method for producing a hardened material using coal ash C as a raw material, and in particular, a method for producing a hardened material using coal ash C as a raw material. Mixed powder of water gypsum size/and ■ type water gypsum with M"j addition of 1.7 is kneaded with water, and by curing, a mechanically strong water phase hardened product is produced. It's about how to do it.

In recent years, in Japan, the development of energy sources has become a national issue in order to reduce dependence on oil, and coal energy has become one of the pillars of energy development.
I'm here. - One of the challenges in the practical application of coal utilization technology to cope with human consumption of coal as a secondary energy source is the treatment of multi-i [i] coal ash generated during coal combustion.

When burning coal, K (ri usually approximately 10 to 2
0 dj: Coal ash of 10% is generated. Normal pulverized coal combustion 1
The so-called pulverized coal combustion ash generated from boilers is classified into bottom ash, cinder ansh, and fly ash, depending on where it is generated, and fly ash accounts for the majority of the generated ash. Conventionally, in Japan, fly ash A portion of the waste is reused as cement mixture (4, cement) and raw materials, and the remainder is disposed of in landfills, etc.

However, with the current method of [1 utilization], it cannot be expected that there will be enough demand to meet the huge amount of coal ash Ti that will be generated in the future. Due to the tightening of environmental regulations, coal ash disposal sites are becoming more and more difficult to dispose of. Processing and effective utilization of all the coal ash generated by method 1 is the first step in the process of processing.In the examination of the coal ash processing technology, it was determined that there would be no environmental pollution. In addition, it is necessary to aim for the use of RL as much as possible.This is because in Japan, where domestically produced resources are scarce and the land is limited, it is essential to try to reuse coal ash as a resource instead of disposing of it in single pieces. This is Tanu.

In consideration of the points mentioned in 1., coal ash can be used for RF+J, soil reclamation, soil improvement work for soft ground, roadbed shrines for road construction, etc. The purpose of this project is to produce a hardened clay body with a large compressive strength as a raw material for stone 11 ingredients, in order to be used in the civil engineering department's large wax.
．． 50 to 94% by weight of coal ash, preferably 60 to 80% by weight, slaked lime d/ and quicklime (
(hereinafter abbreviated as slaked lime, etc.) 5 to 40 tons, preferably 15 to 30 tons, dihydrate gypsum, hemihydrate gypsum, or/and
116su) 1-40 weight tl1%, as desired Fi5-20
A mixed powder consisting of % by weight as a raw material and 1. When producing a cured body, a mixed area containing 10 to 60'rJi (powder 100
After kneading the raw material powder in seawater at an amount of I & weight% of added water based on the weight form, or adding 0 to 3 parts by weight of I.lium chloride to 100 parts by weight of the mixed powder. After adding and kneading water-soluble chlorides other than calcium salts such as potassium chloride and magnesium chloride, and 10 to 60% by weight of water, the kneaded product was mixed using a molding container. By subjecting it to temperature curing in a predetermined shape, the shredded or kneaded product is directly molded into viscera. Target 1: Provides a method for producing a hardened soil body with high compressive strength by putting it in one place and curing it at room temperature in an irregular shape.

Hereinafter, the configuration of the present invention will be explained in detail. In general, the typical properties of coal ash, such as components, composition, and particle size distribution, greatly depend on the coal's production area and combustion history. First of all, depending on the place of coal production, 5102, Al2O3, Cab
, Fe20s, Na2O, K2O, etc., and the coal ash currently generated in Japan is mainly pulverized coal combustion ash, and the particle size distribution differs depending on the location and collection method. For this reason, the first VC, which uses coal ash as its main raw material and produces a water-phase hardened material with high IEE shrinkage strength by curing at room temperature, is determined to determine the appropriateness of the water-phase hardened material depending on the composition and particle size distribution of coal ash. 2! The building conditions are slightly different. The reason for the large ratio of i-1:i′ in terms of manufacturing conditions is as follows:
These are the blending ratio of raw material powder, kneading time and kneading humidity, and room temperature curing time.

The main component of the hydrated hardened product produced by curing at room temperature is ethlinkite (3CaO-AI20a
+ 3CaSO4・32H20), various colored calcium silicate hydrates (xCaO・ysi(h・ZH20)
However, it is ettringite that contributes most to early strength development. Therefore, the blending ratio of the raw H powder is
-11 The most favorable material for the formation of ngite is suitable; the amount of slaked lime, etc. to be added rJ'i is 5 to 40% by weight, preferably 15 to 30% by weight + T1%, and the amount of dihydrate gypsum, etc. to be added is 1 to 40% by weight. , preferably limited to 5 to 20% by weight. Furthermore, the curing period at room temperature is mainly due to the spooning time.

In regular fliA curing, work 1. ．． Normally, it takes 2.3F1 to 1 week to generate IJ ringite and achieve a compressive strength of 2.3 F1 or higher for normal civil engineering knee V11: ff.

The particle size distribution of coal ash also has a large effect on the properties of the hydrated hardened material. Generally, as the particle size of coal ash becomes smaller, that is, as the specific surface area becomes larger, the aqueous phase hardened material tends to achieve a predetermined strength V,': with a shorter curing time. This is the production reaction of Ettringai 1- through solution reaction (through 5olut).
ion reaction), and the dissolution rate 1i of alumina (Al2O3) contained in coal ash is significantly smaller than that of slaked lime-dihydrate gypsum, and it is estimated that the formation rate of ettrinkite depends on the dissolution rate of alumina. This is because it is possible. In this way, the properties of the aqueous phase hardened product are determined by the manufacturing conditions, such as the components and composition of the coal ash, the amount of other raw material powders added, the amount of water mixed, the kneading method and kneading time, and the room temperature curing period. It is necessary to appropriately select each manufacturing condition according to the requirements of the hydrated and cured product.

``The end of the process'' is achieved by simultaneously kneading the mixed powder and seawater at the appropriate blending ratio of each raw material powder. By simultaneously kneading, the hydrated hardened material with high initial strength can be made into a jade by a simple kneading process and curing at room temperature for 1 liter of kneading time. This is what I did.

In the present invention, the amount of mixed water is limited to 10 to 60 tons, but if the amount of mixed water is reduced, the strength will increase to 75 (higher), but the formability will deteriorate, and if the amount of mixed water is less than 1%, it will not be possible to form one piece. ., If you increase the amount of mixed water, it will flow!Ijl,I
However, in the present invention, the water content is limited to about 60% by weight.
The desirable amount of water to be mixed is 30 to 50 tons.

one! In the present invention, by using seawater or an aqueous solution similar to this as mixed pure water, the aqueous phase cured product can be cured (91).
It has an i:1 ratio of increasing strength and shortening the curing period at room temperature. The discovery of the strength of this hydrated hardened material was due to the raw material of NaCL KC.
The presence of a salt such as l-MgCh increases the production rate of ettringite and increases the strength of the aqueous phase cured product.

Examples and comparative examples will be explained below.

The raw material coal ash in Examples and Comparative Examples is commercially available fly ash, and the composition and properties are shown in Table 1. (blank below) Test methods for coal ash and aqueous phase hardened products are shown below.

The plain specific surface area measurement was performed using a powder specific surface area measuring instrument SS-100 manufactured by Takafusa Seisakusho, and was carried out by an air permeation method. The bending strength test uses 20 x 20 x 80 as a test piece.
(rnm) was used, and a 20x20x20 (home) test piece was used as a test piece for the compressive strength test, and a universal test-bell machine manufactured by Instron was used as the test device.

The test method was the constant deflection method. In Examples and Comparative Examples, room temperature curing was carried out indoors without direct sunlight. Details of Examples and Comparative Examples are shown in Table 2.

Example 1 85 parts of coal ash, 10 parts of slaked lime, 5 parts of dihydrate gypsum, 71+
40 parts of water were simultaneously kneaded to obtain a slurry and (-1).The slurry was cured indoors at room temperature for 7 days to obtain a water-phase cured product.The properties of the water-phase cured product were as shown in Table 2.

Comparative Example 1 85 parts of coal ash, 10 parts of slaked lime, 5 parts of dihydrate gypsum, and 40 parts of tap water were simultaneously kneaded to form a slurry, and this slurry was cured at room temperature for 7 days to obtain a hydrated hardened product. The properties of the hydrated and cured product were as shown in Table 2.

Example 2 85 parts of coal ash, 10 parts of slaked lime, 5 parts of dihydrate gypsum, NaC
11.0 parts and 40 parts of tap water were simultaneously kneaded to form a slurry, and this slurry was cured indoors at room temperature for 7 days to obtain a water phase cured product. The properties of the hydrated hardened product were as shown in Table 2.

Example 3 85 parts of coal ash, 10 parts of slaked lime, 5 parts of dihydrate gypsum, MgC
1.0 part of h and 40 parts of tap water were simultaneously kneaded to form a slurry, and this slurry was cured at room temperature for 7 days to obtain a hydrated hardened product. The properties of the aqueous phase cured product were as shown in Table 2.

Comparative Example 2 85 parts of coal ash - 10 parts of slaked lime, 5 parts of dihydrate gypsum, CaC
1.0 part of Iz and 40 parts of tap water were simultaneously kneaded to form a slurry, and this slurry was cured indoors at room temperature for 7 days to obtain a water phase cured product. The properties of the aqueous phase cured product were as shown in Table 2.

(Left below) From Table 2, after kneading the raw material powder and seawater at the same time,
It can be seen that by curing i:', a water-phase hardened body with high initial strength can be obtained [7].

Above theory r-j1. According to the uninvented invention, coal ash, which is a product of JJ1 when burning coal, slaked lime, which is an inexpensive raw material, and/or quicklime, dihydrate gypsum, hemihydrate gypsum, and type 11. After using anhydrous gypsum and kneading with ifG water or a similar aqueous solution,
By applying l'L curing, it is possible to easily and inexpensively produce a hydrated VC with high compressive strength,
The uninvented method is useful as a technology that makes effective use of coal ash and contributes to the production of materials for reclamation, land reclamation, road construction, etc. in the fields of civil engineering and construction. Since the raw material powder and seawater or a similar aqueous solution are kneaded simultaneously, the process is extremely purified, and the mixing time is reduced, making it possible to produce aqueous phase cured products at lower cost. It has the effect of being able to

Claims (1)

[Claims] 1. 50 to 94% by weight of coal ash discharged during coal combustion,
When producing a hardened product using a mixed powder consisting of slaked lime size or/and quicklime 5 to 40 tons ITi type, dihydrate gypsum 1' water gypsum or/and 11 type anhydrous gypsum 1 to 40 tons 1im 1% as a raw material and 12 , 1 to 3 parts of O per 100 parts of the mixed powder (parts of sodium chloride, potassium chloride,
Water-soluble pairs other than calcium salts such as magnesium a-chloride 1. [Kneading the compound and 1 liter of water containing 10 to 60% water, and then molding the kneaded product using a container or a container, and then 1 liter of water. A method for producing a hardened material mainly made of coal ash, characterized by curing with ii'. 2 50-94% by weight of coal ash emitted during coal combustion,
Slaked lime or/and quicklime 5 to 40 h (%, dihydrate gypsum, hemihydrate gypsum or/and ■ type water gypsum 1 to 4
When producing a cured product using a mixed powder containing 0% by weight as a raw material, 100 parts by weight of the mixed powder are mixed with π (1 to 3 parts by weight) of calcium salts such as sodium chloride, magnesium chloride, etc. water-soluble chlorides other than 1
The main raw material is coal ash, which is characterized by adding and kneading 0 to 60 wt/h1% of water at the end of the mixed water, and then curing the kneaded product at room temperature without shaping it into a specific shape. Method for producing a cured product. 3 Water-soluble chlorides other than calcium salts such as sodium chloride, potassium chloride, magnesium chloride, etc. in an amount of 01 to 3 parts by weight per 100 parts of the mixed powder, and 10 to 6 parts by weight
A method for producing a hardened material having coal ash as the main group 1, as set forth in claim 1 and claim 2, in which seawater is used as the water in the 0% by weight mixed water column.