JPH08198648A - Production of coal ash material solidified matter - Google Patents
Production of coal ash material solidified matterInfo
- Publication number
- JPH08198648A JPH08198648A JP7006322A JP632295A JPH08198648A JP H08198648 A JPH08198648 A JP H08198648A JP 7006322 A JP7006322 A JP 7006322A JP 632295 A JP632295 A JP 632295A JP H08198648 A JPH08198648 A JP H08198648A
- Authority
- JP
- Japan
- Prior art keywords
- coal ash
- calcium
- strength
- weight
- curing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
Landscapes
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、石炭灰を主要成分とす
る固化物である石炭灰質固化物の製造方法に関し、特に
建築用パネル等の建材、道路路盤材・砕石等の土木材、
人工骨材等の製造方法を提供するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a coal ash solidified product which is a solidified product containing coal ash as a main component, and particularly to building materials such as building panels, earth and wood such as road roadbed materials and crushed stone,
The present invention provides a method for manufacturing an artificial aggregate or the like.
【０００２】[0002]
【従来の技術】エネルギー源として石炭を利用している
火力発電所や各種の工場では、フライアッシュ等の石炭
灰が大量に産出されている（約４００万トン／年）。こ
のうち、有効利用されるものは約４０％にすぎず、残り
の約６０％は埋め立て処分されているのが現状である。
しかしながら、石炭灰の埋め立て処分場を確保すること
は必ずしも容易ではなく、漁業権の保証やリサイクル法
の制定により埋め立て処分場の確保がますます困難にな
ってきている。従って、今後さらに増大するであろう石
炭灰の有効利用が緊急の課題となっている。2. Description of the Related Art A large amount of coal ash such as fly ash is produced (about 4 million tons / year) at thermal power plants and various factories that use coal as an energy source. Of these, only about 40% is effectively used, and the remaining about 60% is currently landfilled.
However, it is not always easy to secure a landfill disposal site for coal ash, and it is becoming increasingly difficult to secure a landfill disposal site due to the guarantee of fishing rights and the enactment of a recycling law. Therefore, effective use of coal ash, which will increase further in the future, has become an urgent issue.
【０００３】現在のところでは、石炭灰は特開昭６３−
１７２４７号公報および特開平４−３０５０４４号公報
に示されているように無機質系の建築材料の一原料とし
て提案され、または特開平３−１６１７６号公報に示さ
れているように多孔質の濾過助剤の一原料として提案さ
れている。また、特殊な例としては刊行物「日本工業新
聞：人工海底山脈を石炭灰で構築（平成５年２月２６日
発行）」に示されているように、人工魚礁の一原料とし
ても提案されている。これらの提案のうち建築材料、人
工魚礁の一原料として利用する場合には、石炭灰の大量
の利用が期待できる。At present, coal ash is disclosed in JP-A-63-
No. 17247 and Japanese Patent Application Laid-Open No. 4-305044, it is proposed as a raw material for an inorganic building material, or as disclosed in Japanese Patent Application Laid-Open No. 3-16176, a porous filter aid is used. It has been proposed as a raw material for agents. As a special example, it is proposed as a raw material for artificial fish reefs, as shown in the publication "Nippon Kogyo Shimbun: Constructing artificial seabed mountains from coal ash (issued February 26, 1993)". ing. Among these proposals, a large amount of coal ash can be expected when used as a building material or a raw material for artificial fish reefs.
【０００４】[0004]
【発明が解決しようとする課題】ところで、上記した石
炭灰を建築材料、人工魚礁の原料として利用する場合に
は、いずれもセメントと混合して使用されるが、一般に
セメントの水和反応を利用するため石炭灰を主要原料と
するとはいうものの、その混合比率は必ずしも高くな
く、また石炭灰の混合比率を５０重量％以上に高めよう
とする場合には、固化物の強度が低下するという問題が
あり、石炭灰の利用は多くとも４０重量％であった。ま
た、この場合にはセメントを多く使用しているため水に
対する寸法安定性も悪いという問題もあった。これは、
セメントクリンカー中のエーライト（３ＣａＯ・ＳｉＯ
2 ）およびビーライト（２ＣａＯ・ＳｉＯ2 ）等が含ま
れており、これらと石炭灰が水和反応によりカルシウム
シリケート ハイドレートゲル（Ｃ−Ｓ−Ｈ）および
水酸化カルシウムを生成するが、水和反応が遅いため、
固化物中に未反応のエーライトおよびビーライト等が多
く残存することによるものと理解される。また、水和反
応により水酸化カルシウムが多量に生成されるが、この
水和物も寸法安定性に悪影響を及ぼしているものと理解
される。ここで、水に対する寸法安定性が悪いとは、乾
燥−湿潤状態により固化物の体積変化が大きいことをい
う。When the above-mentioned coal ash is used as a raw material for building materials and artificial fish reefs, both are mixed with cement. Generally, the hydration reaction of cement is used. Therefore, although the coal ash is used as the main raw material, the mixing ratio is not necessarily high, and when the mixing ratio of the coal ash is increased to 50% by weight or more, the strength of the solidified product decreases. And the utilization of coal ash was at most 40% by weight. Further, in this case, since a large amount of cement is used, there is a problem that the dimensional stability against water is poor. this is,
Alite in cement clinker (3CaO ・ SiO
2 ) and belite (2CaO · SiO 2 ) are contained, and these and coal ash produce calcium silicate hydrate gel (C—S—H) and calcium hydroxide by hydration reaction. Because the reaction is slow,
It is understood that this is due to the large amount of unreacted alite, belite and the like remaining in the solidified product. Further, although a large amount of calcium hydroxide is produced by the hydration reaction, it is understood that this hydrate also adversely affects the dimensional stability. Here, dimensional stability with respect to water is poor means that the volume change of the solidified product is large due to the dry-wet state.
【０００５】石炭灰とセメントとの組成物をオートクレ
ーブ養生する方法も考えられるが、石炭灰を４０重量％
以上混合した場合には、オートクレーブ養生でも固化物
の強度が十分に発現されないという問題がある。本発明
はこのような従来の問題点を解決して、石炭灰の混合比
率が高く、かつ高強度で、強度のばらつきが小さく、水
に対する寸法安定性が良好な固化物を提供することを目
的としている。A method of autoclave curing a composition of coal ash and cement can be considered, but 40% by weight of coal ash is used.
When mixed as described above, there is a problem that the strength of the solidified product is not sufficiently expressed even in autoclave curing. The present invention aims to solve such conventional problems and to provide a solidified product having a high mixing ratio of coal ash, high strength, little variation in strength, and good dimensional stability against water. I am trying.
【０００６】[0006]
【課題を解決するための手段】上記の課題を解決するた
めに、本発明者が鋭意研究を重ねた結果、石炭灰の品質
管理（嵩密度、平均粒径、及びアルミニウム含有量）、
石炭灰とカルシウム化合物との混合比率及び水熱処理に
より、従来のものに比べ格段に優れている固化物となる
ことを見いだした。すなわち、本発明の石炭灰質固化物
の製造方法は、嵩密度が小さくとも０．８ｇ／ｃｍ3 、
平均粒径が５〜４０μｍで、アルミニウム量がＡｌ2 Ｏ
3 換算で多くとも３５重量％の石炭灰と、カルシウム化
合物とを重量比を４０：６０〜９５：５に混合する工程
と、所定の形状に成形する工程と、１２０℃以上の温度
及び高圧下で水熱処理する工程を含むことを特徴とする
ものである。In order to solve the above problems, as a result of intensive studies by the present inventors, quality control of coal ash (bulk density, average particle size, and aluminum content),
It has been found that the solidified product is significantly superior to the conventional one by the mixing ratio of coal ash and calcium compound and hydrothermal treatment. That is, according to the method for producing a coal ash solidified product of the present invention, even if the bulk density is small, 0.8 g / cm 3 ,
The average particle size is 5 to 40 μm and the amount of aluminum is Al 2 O
A step of mixing coal ash of at most 35% by weight in terms of 3 and a calcium compound at a weight ratio of 40:60 to 95: 5, a step of molding into a predetermined shape, and a temperature of 120 ° C. or higher and under high pressure. The method is characterized in that it includes a step of performing hydrothermal treatment with.
【０００７】また、前記カルシウム化合物が、酸化カル
シウム、水酸化カルシウム、炭酸カルシウム、およびケ
イ酸カルシウムの少なくとも１種類以上のカルシウム化
合物が好適である。Further, the calcium compound is preferably at least one kind of calcium compound of calcium oxide, calcium hydroxide, calcium carbonate, and calcium silicate.
【０００８】また、前記水熱処理に先だって、３０〜１
００℃で養生することも好適である。Prior to the hydrothermal treatment, 30 to 1
Curing at 00 ° C is also suitable.
【０００９】前記嵩密度の測定は、ＪＩＳ Ｚ ２５０
４ の測定方法に準拠した。The bulk density is measured according to JIS Z 250.
It was based on the measuring method of 4.
【００１０】[0010]
【作用】石炭灰については、嵩密度が０．８ｇ／ｃｍ3
以上、好ましくは１．０ｇ／ｃｍ3 以上である。嵩密度
が０．８ｇ／ｃｍ3 未満では石炭灰質固化物の強度が十
分発現されず、また、強度のばらつきも大きくなるから
である。また、石炭灰の平均粒径は、５〜４０μｍ，好
ましくは１０〜３０μｍである。平均粒径が５μｍ未満
では固化物の強度が十分発現されず、また、平均粒径が
４０μｍを越える場合には強度が低下するとともに強度
のばらつきが大きくなるからである。これらの理由は定
かではないが石炭灰質固化物の強度に、石炭灰が骨材と
して関与しているものと推測される。したがって、嵩密
度の小さい石炭灰は粒子は中空状のものが多くなり、強
度の低下及び強度のばらつき増大をもたらすものと考え
られる。また、平均粒径５μｍ未満の石炭灰は、水熱処
理であるオートクレーブ養生後では、石炭灰粒子として
は残存しにくくなり、石炭灰が骨材として関与しないた
め、強度向上効果をもたらさないものと考えられる。一
方、平均粒径４０μｍを越える石炭灰は、オートクレー
ブ養生後でも石炭灰粒子としては残存するものの、粒径
が大きすぎて逆に欠陥として作用するものと考えられ
る。なお、石炭灰の粒度分布については、強度向上及び
強度のばらつき低減の点で平均粒径の１／４〜４倍に６
０％以上の粒子が入る分布が好ましい。石炭灰は強度の
点でフライアッシュが好ましいが、ボトムアッシュでも
粉砕処理することにより使用できる。[Function] For coal ash, the bulk density is 0.8 g / cm 3
Or more, preferably 1.0 g / cm 3 or more. This is because if the bulk density is less than 0.8 g / cm 3 , the strength of the coal ash solidified product is not sufficiently expressed, and the dispersion of the strength becomes large. The average particle size of coal ash is 5 to 40 μm, preferably 10 to 30 μm. This is because if the average particle size is less than 5 μm, the strength of the solidified product is not sufficiently exhibited, and if the average particle size exceeds 40 μm, the strength decreases and the dispersion of the strength increases. Although these reasons are not clear, it is presumed that coal ash is involved in the strength of the coal ash solidified product as an aggregate. Therefore, it is considered that the coal ash having a low bulk density has many hollow particles, resulting in a decrease in strength and an increase in strength variation. Further, coal ash having an average particle size of less than 5 μm is unlikely to remain as coal ash particles after autoclave curing, which is a hydrothermal treatment, and since coal ash does not participate as an aggregate, it is considered that it does not bring about a strength improving effect. To be On the other hand, although coal ash having an average particle size of more than 40 μm remains as coal ash particles even after curing in an autoclave, it is considered that the particle size is too large and conversely acts as a defect. Regarding the particle size distribution of coal ash, the average particle size is ¼ to 4 times the average particle size in order to improve the strength and reduce the variation in strength.
A distribution in which 0% or more of particles are contained is preferable. Fly ash is preferable as the coal ash in terms of strength, but bottom ash can also be used by pulverizing.
【００１１】また、石炭灰の組成に関しては、アルミニ
ウム量がAl2O3 換算で３５重量％以下、好ましくは３０
重量％以下である。アルミニウム量がAl2O3 換算で３５
重量％を越えると固化物の強度の低下及び強度のばらつ
き増大をもたらす。これは、オートクレーブ養生により
石炭灰質固化物中にハイドロガーネットが生成しやすく
なり、これが欠陥として作用するものと考えられる。石
炭灰のその他の組成については、Ｓｉ成分は、SiO2に換
算して３０〜８０重量％、Ｆｅ成分は、Fe2O3に換算し
て１５重量％以下が強度特性上好ましく、未燃炭素量が
５重量％以上であっても何等問題はない。なお、石炭灰
は一般に発生する微粉炭石炭灰のみならず常圧ないし加
圧流動床燃焼発電システムより発生する石炭灰にも使用
できる。With respect to the composition of coal ash, the amount of aluminum is 35% by weight or less, preferably 30% in terms of Al 2 O 3.
% By weight or less. The amount of aluminum is 35 in terms of Al 2 O 3.
When the content exceeds the weight%, the strength of the solidified product is lowered and the variation in strength is increased. It is considered that this is because hydrogarnet is easily generated in the coal ash solidified product due to autoclave curing, and this acts as a defect. Regarding the other composition of the coal ash, the Si component is preferably 30 to 80% by weight in terms of SiO 2 , and the Fe component is preferably 15% by weight or less in terms of Fe 2 O 3 in terms of strength characteristics. There is no problem even if the amount is 5% by weight or more. The coal ash can be used not only for pulverized coal ash generally generated, but also for coal ash generated from a normal pressure or pressurized fluidized bed combustion power generation system.
【００１２】また、石炭灰の混合比率が４０重量％未満
の場合には石炭灰質固化物の強度及び寸法安定性が低
く、９５重量％を越えると固化しにくく石炭灰質固化物
としての強固な形態を保持しえない。したがって、石炭
灰の混合比は、４０〜９５重量％、好ましくは７０〜９
０重量％である。When the mixing ratio of coal ash is less than 40% by weight, the strength and dimensional stability of the solidified material of coal ash is low, and when it exceeds 95% by weight, it is hard to solidify and has a strong form as a solidified material of coal ash. Can't hold. Therefore, the mixing ratio of coal ash is 40 to 95% by weight, preferably 70 to 9%.
0% by weight.
【００１３】しかして、本発明において採用できるカル
シウム化合物としては、酸化カルシウム、水酸化カルシ
ウム、ケイ酸カルシウム、炭酸カルシウム等を挙げるこ
とができ、使用に際してはこれらの各化合物を単独でま
たは２種以上のものを併用することができる。強度特性
上、平均粒径５００μｍ以下の粉体が好ましい。ここ
で、ケイ酸カルシウムはエーライト、ビーライト等を挙
げることができ、これらを含む普通ポルトランドセメン
ト等の各種ポルトランドセメントも用いることができ
る。これらの各化合物のうちでは、作用効果の点からい
えば、特に酸化カルシウム、水酸化カルシウム、ケイ酸
カルシウムが好適である。なお、貝の焼却灰は酸化カル
シウム含むため用いることができる。また、石膏等の硫
酸カルシウムは、トバモライト以外の生成物ができるた
めに不適当である。The calcium compounds that can be used in the present invention include calcium oxide, calcium hydroxide, calcium silicate, calcium carbonate and the like. In use, these compounds may be used alone or in combination of two or more. Can be used together. In terms of strength characteristics, powder having an average particle size of 500 μm or less is preferable. Here, examples of calcium silicate include alite and belite, and various portland cements such as ordinary portland cement containing these can also be used. Among these compounds, calcium oxide, calcium hydroxide and calcium silicate are particularly preferable from the viewpoint of action and effect. The incineration ash of shellfish can be used because it contains calcium oxide. Further, calcium sulfate such as gypsum is unsuitable because it produces products other than tobermorite.
【００１４】また、オートクレーブ養生温度は１２０℃
以上、好ましくは１３０〜２５０℃、養生時間は２時間
以上が好ましい。なお、飽和蒸気温度１２０℃のときの
絶対圧力は、約２Ｋｇ／ｃｍ2 である。オートクレーブ
養生温度が１２０℃未満では、石炭灰質固化物の強度が
十分発現されず、また、水に対する寸法安定性も悪化す
るからである。１２０℃未満のオートクレーブ養生で
は、強度向上効果のあるトバモライトの生成が少なく、
また、寸法安定性に悪影響を及ぼす水酸化カルシウム、
ケイ酸カルシウムが多く残存するためと考えられる。な
お、寸法安定性の悪化については、この他、Ｃ−Ｓ−Ｈ
ゲルも影響を及ぼしていると考えられる。１２０℃未満
のオートクレーブ養生では、トバモライトの生成が不十
分なため、Ｃ−Ｓ−Ｈゲルが多く残り、このＣ−Ｓ−Ｈ
ゲルの水は乾燥−湿潤状態により大きく変化する。その
結果、固化物の体積は、この水の出入りに伴い大きく変
化し、寸法安定性が悪化するものと推察する。石炭灰の
混合比が４０重量％未満の場合でも寸法安定性が悪化し
たが、この場合も水酸化カルシウム、ケイ酸カルシウム
の他、Ｃ−Ｓ−Ｈゲルも悪影響を及ぼしているものと考
えられる。なお、水中に浸漬した状態でのオートクレー
ブ養生は好ましくない。The autoclave curing temperature is 120 ° C.
As described above, preferably 130 to 250 ° C., and the curing time is preferably 2 hours or more. The absolute pressure at a saturated steam temperature of 120 ° C. is about 2 Kg / cm 2 . This is because if the autoclave curing temperature is lower than 120 ° C, the strength of the coal ash solidified product is not sufficiently expressed, and the dimensional stability against water is deteriorated. In autoclave curing below 120 ° C, the generation of tobermorite, which has the effect of improving strength, is small,
In addition, calcium hydroxide, which adversely affects dimensional stability,
It is considered that a large amount of calcium silicate remains. Regarding deterioration of dimensional stability, in addition to this, C-S-H
The gel is also thought to have an effect. In autoclave curing at less than 120 ° C, the production of tobermorite is insufficient, so a large amount of C-S-H gel remains, and this C-S-H
The water of the gel changes greatly depending on the dry-wet condition. As a result, it is assumed that the volume of the solidified substance changes greatly with the inflow and outflow of water, and the dimensional stability deteriorates. The dimensional stability deteriorated even when the mixing ratio of coal ash was less than 40% by weight, but in this case as well, calcium hydroxide, calcium silicate, and C-S-H gel are considered to have an adverse effect. . Note that autoclave curing in a state of being immersed in water is not preferable.
【００１５】石炭灰質原料を所定の形状に成形する際に
は、同原料に水を所定量添加することが強度向上の上で
好ましい。このように調製された原料を使用して、プレ
ス成形、押し出し成形、流し込み成形、締め固め成形又
は遠心力締め固め成形等により所定の形状に成形する。
添加水分量は固形分に対して、プレス成形では１〜２５
重量％、押し出し成形では、１５〜３０重量％、流し込
み成形では２０〜４５重量％、締め固め成形では１５〜
４０重量％が好ましい。この場合、バインダー、減水
剤、保水剤、防水剤、流動化剤、収縮低減剤等の混和剤
を添加してもよく、また石炭灰質固化物の強度の向上、
比重の調整、コストの低減などのために、珪砂、火成
岩、高炉スラグ、パーライト、ＡＬＣの屑、グラスファ
イバー、繊維、パルプ等を添加することもできる。バイ
ンダーとしては、メチルセルロース、エチルセルロー
ス、カルボキシメチルセルロース、ヒドロキシエチルセ
ルロース、ポリビニルアルコール等が挙げられる。混和
剤としては、アルキルアリルスルホン酸、ナフタリンス
ルホン酸ホルマリン高縮合物、ナフタリンスルホン酸と
リグニンスルホン酸の共縮合物、アルキルアリルスルホ
ネートポリマー、アルキルアリルスルホネート、ジエチ
ルナフタリンのホルマリン縮合物、オレフィン／無水マ
レイン酸共縮合物、ポリカルボン酸塩、変性メチロール
メラミン縮合物等が挙げられる。When the coal ash material is molded into a predetermined shape, it is preferable to add a predetermined amount of water to the material in order to improve the strength. Using the raw material thus prepared, it is molded into a predetermined shape by press molding, extrusion molding, cast molding, compaction molding, centrifugal compaction molding or the like.
The amount of added water is 1 to 25 in press molding with respect to the solid content.
% By weight, 15-30% by weight for extrusion molding, 20-45% by weight for cast molding, 15-% for compaction molding
40% by weight is preferred. In this case, a binder, a water reducing agent, a water retention agent, a waterproofing agent, a fluidizing agent, an admixture such as a shrinkage reducing agent may be added, and the strength of the coal ash solidified product is improved,
Silica sand, igneous rock, blast furnace slag, perlite, ALC scraps, glass fibers, fibers, pulp and the like can be added to adjust the specific gravity and reduce the cost. Examples of the binder include methyl cellulose, ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol and the like. As the admixture, alkyl allyl sulfonic acid, naphthalene sulfonic acid formalin high condensation product, naphthalene sulfonic acid and lignin sulfonic acid co-condensation product, alkyl allyl sulfonate polymer, alkyl allyl sulfonate, diethyl naphthalene formalin condensation product, olefin / maleic anhydride Examples thereof include acid cocondensates, polycarboxylic acid salts, and modified methylolmelamine condensates.
【００１６】また、得られた成形物をオートクレーブ養
生する際、特にカルシウム化合物として炭酸カルシウム
を使用した場合、アルカリを包含させた状態でオートク
レーブ養生を行うと耐凍結融解性が良好になる。この理
由は定かではないが、アルカリの存在により石炭灰とカ
ルシウム化合物の反応が助長され、固化物中の気孔が一
層減少するとともに、反応生成物が強固に固着した状態
になることによるものと推測される。アルカリとしては
アルカリ金属の水酸化物（ＮａＯＨ、ＫＯＨ等）、アル
カリ金属炭酸塩（Ｎａ2 ＣＯ3 等）、およびアンモニア
等を挙げることができる。これらの各化合物のうちで
は、作用効果の点からいえばアルカリ金属の水酸化物、
アンモニア、アルカリ金属炭酸塩の順であり、これらの
うちアルカリ金属の水酸化物が好ましく、中でも水酸化
ナトリウムがより好ましい。成形物中のアルカリの含有
量については、成形物中の石炭灰に対して重量比で０．
００１〜２０％の範囲が好ましく、より好ましくは０．
１〜１０％であって、この範囲においては、強度および
寸法安定性とともに耐凍結融解性の良好な固化物を得る
ことができる。アルカリを成形物中に包含させる手段と
しては、アルカリを石炭灰およびカルシウム化合物の混
合物である石炭灰質原料中に粉末または水溶液の状態で
添加する手段、成形物に水溶液の状態で含浸させる手段
等があり、特にアルカリを水溶液の状態で包含させる手
段が好ましい。When the obtained molded product is autoclaved, particularly when calcium carbonate is used as the calcium compound, the freeze-thaw resistance becomes good when the autoclave is cured with an alkali contained. The reason for this is not clear, but it is presumed that the presence of alkali promotes the reaction between the coal ash and the calcium compound, further reducing the pores in the solidified product, and the reaction product becomes firmly fixed. To be done. Examples of the alkali include alkali metal hydroxides (NaOH, KOH, etc.), alkali metal carbonates (Na 2 CO 3, etc.), and ammonia. Among these compounds, in terms of action and effect, alkali metal hydroxide,
Ammonia and alkali metal carbonates are listed in this order, of which alkali metal hydroxides are preferred, and sodium hydroxide is more preferred. Regarding the content of alkali in the molded product, the weight ratio to the coal ash in the molded product was 0.
It is preferably in the range of 001 to 20%, more preferably 0.
It is from 1 to 10%, and in this range, a solidified product having excellent strength and dimensional stability and freeze-thaw resistance can be obtained. Examples of means for incorporating an alkali in a molded product include a means for adding the alkali in a powder or aqueous solution state to a coal ash raw material which is a mixture of coal ash and a calcium compound, a means for impregnating the molded product in an aqueous solution state, and the like. In particular, a means of incorporating an alkali in the form of an aqueous solution is preferable.
【００１７】また、得られた成形物を、オートクレーブ
養生に先立って、養生温度３０〜１００℃、より好まし
くは４０〜９０℃で、養生時間２時間以上、より好まし
くは５時間以上養生すると、固化物の強度向上の上で好
ましい。養生には、湿潤養生、湛水養生、散水養生、被
膜養生等が挙げられるが、湿潤養生、湛水養生がより好
ましい。If the obtained molded product is cured at a curing temperature of 30 to 100 ° C., more preferably 40 to 90 ° C. for a curing time of 2 hours or more, more preferably 5 hours or more, prior to autoclave curing, it solidifies. It is preferable for improving the strength of the product. Examples of the curing include wet curing, flooding curing, sprinkling curing, film curing and the like, but wet curing and flooding curing are more preferable.
【００１８】なお、流し込み及び締め固め成形では、成
形の際、振動を加えることは巻き込み気泡が除去でき、
強度向上及び保形性の点で好ましい。振動は振幅０．１
〜５ｍｍ，振動数５００〜５０Ｈｚが好ましい。また、
流し込み、締め固め及びプレス成形では、型枠への泥漿
及び粒体の供給を数回に分けることにより成分等の異な
る層が多層形成される多層構造を作製することも可能と
なる。この多層構造を利用することにより表面の着色が
可能となり外観が重要視される道路用歩道板及び建材に
は好適である。また、骨材の添加量あるいは気孔率を連
続的に変化させることもでき、傾斜機能を持つ材料が作
製できる。また、流し込みでは鉄筋等の補強材も導入で
きる。また、石炭灰質固化物を通常用いられているロー
ルクラッシャ、ジョークラッシャ等で所定の粒径に粉砕
した場合には採石、人工骨材、道路用路盤材として用い
ることができる。In the casting and compaction molding, it is possible to remove entrained air bubbles by applying vibration during molding.
It is preferable in terms of strength improvement and shape retention. Vibration has an amplitude of 0.1
-5 mm and a frequency of 500-50 Hz are preferable. Also,
In pouring, compaction and press molding, it is also possible to produce a multilayer structure in which layers having different components are formed in multiple layers by dividing the supply of sludge and granules to the mold several times. The use of this multilayer structure makes it possible to color the surface and is suitable for road sidewalk boards and building materials where appearance is important. Further, the amount of aggregate added or the porosity can be continuously changed, and a material having a gradient function can be produced. In addition, reinforcing materials such as reinforcing bars can be introduced by pouring. Further, when the coal ash solidified product is crushed to a predetermined particle size by a commonly used roll crusher, jaw crusher, etc., it can be used as a quarry, an artificial aggregate, and a roadbed material.
【００１９】本発明に係る製造方法によれば、固化物は
水熱処理であるオ−トクレ−ブ養生以前の成形物の状態
では、原料成分の各微粒子が互いに密に充填した状態を
呈しており、その後のオ−トクレ−ブ養生により各微粒
子間及び微粒子表面に、石炭灰中のＳｉＯ2,Ａｌ2 Ｏ3,
Ｆｅ2 Ｏ3 等と、ＣａＯ等のカルシウム化合物の各成分
が反応して、主としてトバモライト（５ＣａＯ・６Ｓｉ
Ｏ2 ・５Ｈ2 Ｏ）、その他のＣ−Ｓ−Ｈゲル（カルシウ
ム シリケ─ト ハイドレ─トゲル）が生成される。こ
の結果、固化物を構成する各微粒子は、主に石炭灰粒
子、トバモライト結晶、その他のＣ−Ｓ−Ｈゲルとな
り、互いに強固に固着した状態で気孔率の小さい硬化体
となって，高強度で，強度のばらつきも小さく水に対す
る寸法安定性に優れた固化物を得ることができる。According to the production method of the present invention, the solidified product is in the state of the molded product before the autoclave curing, which is a hydrothermal treatment, in which the respective fine particles of the raw material components are closely packed with each other. Then, SiO 2 and Al 2 O 3 in the coal ash were formed between the respective fine particles and on the surface of the fine particles by the subsequent autoclave curing .
Fe 2 O 3 etc. reacts with each component of the calcium compound such as CaO, mainly tobermorite (5CaO ・ 6Si).
O 2 .5H 2 O) and other C—S—H gels (calcium silicate hydrate gels) are produced. As a result, the fine particles constituting the solidified product mainly become coal ash particles, tobermorite crystals, and other C-S-H gels, and become a hardened product having a small porosity in a state where they are firmly fixed to each other and have high strength. Thus, it is possible to obtain a solidified product with small strength variations and excellent dimensional stability against water.
【００２０】したがって、得られる石炭灰質固化物は、
圧縮強度が例えば４００ｋｇ／ｃｍ2 以上という高強度
で強度のばらつきも小さいものとなり、コンクリートパ
ネル、コンクリート杭等の高強度のコンクリート製品へ
の適用が可能であるとともに、水に対する寸法安定性が
良好なため水場での使用が可能である。このため、本発
明の製造方法で製造された石炭灰質固化物は、建築用コ
ンクリートパネル等の建材、道路路盤材・砕石等の土木
材、人工骨材等広い分野で大量に利用することができる
とともに、当該石炭灰質固化物の原料中の石炭灰の混合
比が高いことから、石炭灰の大量利用が可能となる。Therefore, the obtained coal ash solidified product is
High compressive strength of, for example, 400 kg / cm 2 or more and small variation in strength, making it applicable to high-strength concrete products such as concrete panels and concrete piles, and having good dimensional stability against water. Therefore, it can be used in water. Therefore, the coal ash solidified product produced by the production method of the present invention can be used in large amounts in a wide range of fields such as building materials such as concrete panels for construction, earth and timber such as road roadbed materials and crushed stone, and artificial aggregates. At the same time, since the mixing ratio of the coal ash in the raw material of the coal ash solidified product is high, it is possible to use the coal ash in a large amount.
【００２１】[0021]
【実施例】次に、本発明を実施例に基づき説明する。 （実施例）石炭灰として嵩密度０．８〜１．４ｇ／ｃｍ
3 、平均粒子径５〜４０μｍのフライアッシュ（成分:
SiO2 ３０〜８０重量％，Al2O3 １８〜３５重量％，Fe
2O3 １５重量％以下）を使用するとともに，カルシウム
化合物として，平均粒径１〜１００μｍの酸化カルシウ
ム、水酸化カルシウム、炭酸カルシウム、普通ポルトラ
ンドセメントの４種類を使用し，これらを適宜の重量混
合するとともに、１０〜３０重量％の水と、減水剤を添
加して混合し，各種の石炭灰質原料を調製した。プレス
成形はプレス圧５０Ｋｇ／ｃｍ2 で成形し、６０℃２０
時間湿潤状態で養生を行い、円板状の固化物素地（直径
１２０ｍｍ，厚さ５０ｍｍ）を得た。流し込み成形は金
型に石炭灰質原料泥漿を流し込み、６０℃２０時間湿潤
状態で養生を行い、円板状の固化物素地（直径１２０ｍ
ｍ，厚さ５０ｍｍ）を得た。次いで、１２０〜２７０℃
の温度条件で２０時間オ─トクレ─ブ養生を行った。EXAMPLES Next, the present invention will be explained based on examples. (Example) Bulk density of 0.8 to 1.4 g / cm as coal ash
3 , fly ash with an average particle size of 5-40 μm (component:
SiO 2 30 to 80 wt%, Al 2 O 3 18~35 wt%, Fe
2 O 3 15% by weight or less) and four kinds of calcium compounds having an average particle diameter of 1 to 100 μm, that is, calcium oxide, calcium hydroxide, calcium carbonate, and ordinary Portland cement are used, and these are appropriately mixed by weight. In addition, 10 to 30% by weight of water and a water reducing agent were added and mixed to prepare various coal ash raw materials. Press molding is carried out at a pressing pressure of 50 Kg / cm 2 and 60 ° C. for 20 minutes.
Curing was performed in a wet state for a period of time to obtain a disk-shaped solidified body (diameter 120 mm, thickness 50 mm). The casting is performed by pouring the coal ash raw material slurry into a mold, curing at 60 ° C. for 20 hours in a wet state, and a disk-shaped solidified material base (diameter 120 m
m, thickness 50 mm) was obtained. Then 120-270 ° C
The autoclave was cured for 20 hours under the above temperature conditions.
【００２２】次に、表１に基づき実施例について詳細に
説明する。実施例１は、嵩密度１．１ｇ／ｃｍ3 、平均
粒径１３μｍ、アルミニウム量がAl2O3 換算で２１重量
％の石炭灰９５重量％と酸化カルシウム２重量％と水酸
化カルシウム３重量％の石炭灰質原料を用い、１６０℃
でオートクレーブ養生した。実施例２は、嵩密度１．３
ｇ／ｃｍ3 、平均粒径２２μｍ、アルミニウム量がAl2O
3 換算で３０重量％の石炭灰９０重量％と酸化カルシウ
ム１０重量％の石炭灰質原料を用い、１８０℃でオート
クレーブ養生した。以下表１の通りである。なお、実施
例１及び１３は、湿潤状態での養生を行わないでオート
クレーブ養生した。Next, examples will be described in detail with reference to Table 1. In Example 1, 95% by weight of coal ash having a bulk density of 1.1 g / cm 3 , an average particle size of 13 μm, and an aluminum amount of 21% by weight in terms of Al 2 O 3 , 2% by weight of calcium oxide, and 3% by weight of calcium hydroxide. 160 ℃ using the coal ash raw material
Autoclaved in. Example 2 has a bulk density of 1.3.
g / cm 3 , average particle size 22 μm, aluminum content is Al 2 O
Autoclave curing was performed at 180 ° C. using a coal ash raw material containing 90% by weight of 30% by weight of coal ash and 10% by weight of calcium oxide in terms of 3 . It is as shown in Table 1 below. In addition, in Examples 1 and 13, autoclave curing was performed without performing curing in a wet state.
【００２３】こうして得られた石炭灰質固化物について
外観を観察するとともに，圧縮強度及び水に対する寸法
安定性を測定して，これらの結果を表１に示す。ただ
し，石炭灰質固化物の外観の観察では固化物における亀
裂などの損傷の有無，形態保持性の強弱を判定し，良好
なものを○印，不良なものを×印で表示している。ま
た，圧縮強度の測定については，円板面上下に直径５０
ｍｍの金属板をのせ、これに圧力をかける方法で、その
他はＪＩＳ Ａ １１０８ に従いオートグラフにより
行い、１０個の試料の平均を圧縮強度とし、その標準偏
差をばらつきとした。寸法安定性は、得られた石炭灰質
固化物を切り出し、４０×５０×１００ｍｍの測定試料
を作製し、この試料を乾燥器に入れ６０℃２４時間乾燥
後、デシケータで常温まで冷却し、常温の水中に２４時
間浸漬後の寸法変化率（％）で示した。寸法変化率は、
ＪＩＳ Ａ ５４１８の測定方法にしたがった。 （比較例）表２に示す通り、石炭灰として嵩密度０．５
〜１．２ｇ／ｃｍ3 、平均粒子径１〜６０μｍのフライ
アッシュ（成分: SiO2 ３０〜８０重量％，Al2O3 １８
〜４０重量％，Fe2O3 １５重量％以下）を使用するとと
もに，カルシウム化合物として，平均粒径１〜１００μ
ｍの酸化カルシウム、水酸化カルシウム、普通ポルトラ
ンドセメント、石膏の４種類を使用した。その他は、実
施例と同様とした。なお、比較例２４は、オ─トクレ─
ブ養生せずに、６０℃２０時間蒸気養生した。The appearance of the coal ash solidified product thus obtained was observed, and the compressive strength and dimensional stability against water were measured. The results are shown in Table 1. However, by observing the appearance of the coal ash solidified product, the presence or absence of damage such as cracks in the solidified product and the strength of shape retention were judged, and good ones were marked with a circle, and bad ones were marked with a cross. For the measurement of compressive strength, the diameter of 50
A metal plate of mm was placed on the plate, and pressure was applied to the plate. Others were performed by an autograph according to JIS A 1108. The average of 10 samples was taken as the compressive strength, and the standard deviation thereof was taken as the variation. For dimensional stability, the obtained coal ash solidified product is cut out to prepare a measurement sample of 40 × 50 × 100 mm, which is put in a drier and dried at 60 ° C. for 24 hours, then cooled to room temperature with a desiccator, The dimensional change rate (%) after immersion in water for 24 hours is shown. The dimensional change rate is
According to the measurement method of JIS A 5418. (Comparative Example) As shown in Table 2, coal ash has a bulk density of 0.5.
To 1.2 g / cm 3, fly ash (component having an average particle size of 1~60μm: SiO 2 30~80 wt%, Al 2 O 3 18
-40% by weight, Fe 2 O 3 15% by weight or less), and a calcium compound having an average particle size of 1 to 100 μm.
m of calcium oxide, calcium hydroxide, ordinary Portland cement, and gypsum were used. Others were the same as in the example. In addition, Comparative Example 24 is an automatic
Steam curing was performed at 60 ° C. for 20 hours without curing.
【００２４】[0024]
【表１】 [Table 1]
【００２５】[0025]
【表２】 [Table 2]
【００２６】[0026]
【発明の効果】以上説明からも明らかなように、本発明
によると石炭灰混合比率が高く、高強度で、強度ばらつ
きが小さく、水に対する寸法安定性の良好な石炭灰固化
物が得られ、建材、土木材、人工骨材等広い分野に適用
できるため、従来から苦慮していた産業廃棄物である石
炭灰を有効に大量利用が実現でき、本発明の効果は極め
て多大である。As is apparent from the above description, according to the present invention, a coal ash solidified product having a high coal ash mixing ratio, high strength, small strength variation, and good dimensional stability against water can be obtained. Since it can be applied to a wide range of fields such as building materials, earth and timber, artificial aggregates, etc., it is possible to effectively use a large amount of coal ash, which has been a difficult industrial waste, and the effect of the present invention is extremely great.
Claims (3)
平均粒径が５〜４０μｍで、アルミニウム量がＡｌ2 Ｏ
3 換算で多くとも３５重量％の石炭灰と、カルシウム化
合物とを重量比を４０：６０〜９５：５に混合する工程
と、成形する工程と、１２０℃以上の温度及び高圧下で
水熱処理する工程を含むことを特徴とする石炭灰質固化
物の製造方法。1. A bulk density of at least 0.8 g / cm 3 ,
The average particle size is 5 to 40 μm and the amount of aluminum is Al 2 O
A step of mixing coal ash of at most 35% by weight in terms of 3 and a calcium compound in a weight ratio of 40:60 to 95: 5, a step of molding, and a hydrothermal treatment at a temperature of 120 ° C. or higher and under high pressure. A method for producing a coal ash solidified product, which comprises a step.
ム、水酸化カルシウム、炭酸カルシウム、およびケイ酸
カルシウムの少なくとも１種類以上のカルシウム化合物
である請求項１に記載の石炭灰質固化物の製造方法。2. The method for producing a coal ash solidified product according to claim 1, wherein the calcium compound is at least one calcium compound of calcium oxide, calcium hydroxide, calcium carbonate, and calcium silicate.
℃で養生する工程を含む請求項１に記載の石炭灰質固化
物の製造方法。3. 30 to 100 prior to the hydrothermal treatment
The method for producing a coal ash solidified product according to claim 1, including a step of curing at ℃.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7006322A JP2843520B2 (en) | 1995-01-19 | 1995-01-19 | Method for producing coal ash solidified material |
| US08/400,972 US5584895A (en) | 1994-04-18 | 1995-03-08 | Process for preparing solidified material containing coal ash |
| EP19950301626 EP0678488B1 (en) | 1994-04-18 | 1995-03-13 | Process for preparing solidified material containing coal ash |
| DE1995604562 DE69504562T2 (en) | 1994-04-18 | 1995-03-13 | Process for the preparation of a solid containing coal ash |
| KR1019950005952A KR0132739B1 (en) | 1994-04-18 | 1995-03-21 | Process for preparing solidified material containing coal ash |
| CN95104373A CN1117032A (en) | 1994-04-18 | 1995-04-10 | Process for preparing solidified material containing coal ash |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7006322A JP2843520B2 (en) | 1995-01-19 | 1995-01-19 | Method for producing coal ash solidified material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08198648A true JPH08198648A (en) | 1996-08-06 |
| JP2843520B2 JP2843520B2 (en) | 1999-01-06 |
Family
ID=11635139
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7006322A Expired - Lifetime JP2843520B2 (en) | 1994-04-18 | 1995-01-19 | Method for producing coal ash solidified material |
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| Country | Link |
|---|---|
| JP (1) | JP2843520B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008013919A (en) * | 2006-07-03 | 2008-01-24 | Tsuneo Takaishi | Rising foundation member for wall base |
| JP2015117161A (en) * | 2013-12-19 | 2015-06-25 | 太平洋マテリアル株式会社 | Mortar composition for molding |
| WO2017131330A1 (en) * | 2016-01-29 | 2017-08-03 | 경상대학교 산학협력단 | Solidifying agent including oyster shells treated with sulfuric acid, and construction method using same |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104016624B (en) * | 2014-05-09 | 2016-01-20 | 太仓市金锚新材料科技有限公司 | High-strength low-density flame retardant inorganic wall heat insulation material and preparation method thereof |
-
1995
- 1995-01-19 JP JP7006322A patent/JP2843520B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008013919A (en) * | 2006-07-03 | 2008-01-24 | Tsuneo Takaishi | Rising foundation member for wall base |
| JP2015117161A (en) * | 2013-12-19 | 2015-06-25 | 太平洋マテリアル株式会社 | Mortar composition for molding |
| WO2017131330A1 (en) * | 2016-01-29 | 2017-08-03 | 경상대학교 산학협력단 | Solidifying agent including oyster shells treated with sulfuric acid, and construction method using same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2843520B2 (en) | 1999-01-06 |
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