JP4509269B2 - Artificial aggregate and method for producing the same - Google Patents
Artificial aggregate and method for producing the same Download PDFInfo
- Publication number
- JP4509269B2 JP4509269B2 JP34012499A JP34012499A JP4509269B2 JP 4509269 B2 JP4509269 B2 JP 4509269B2 JP 34012499 A JP34012499 A JP 34012499A JP 34012499 A JP34012499 A JP 34012499A JP 4509269 B2 JP4509269 B2 JP 4509269B2
- Authority
- JP
- Japan
- Prior art keywords
- less
- specific gravity
- coal ash
- artificial
- aggregate
- 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.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B18/02—Agglomerated materials, e.g. artificial aggregates
- C04B18/023—Fired or melted materials
-
- 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
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Civil Engineering (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Processing Of Solid Wastes (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、火力発電所や石炭焚きボイラーなどから排出される石炭灰(フライアッシュ)を主原料とする人工骨材について、石炭灰の特定成分を調整することにより、キルンで安定に焼成できるようにし、比較的密度が大きく高強度で低吸水率の人工骨材を安定に製造できる方法と、その人工骨材に関する。
【０００２】
【従来の技術】
石炭灰を主原料とした人工骨材とその製造方法が従来から数多く提案されている。その製造方法の多くは、原料の石炭灰を焼成時に発泡膨張させて内部に多数の気泡を含有させた多孔質の軽量骨材に関するものであるが、このような多孔質軽量骨材は一般に圧縮強度が弱く、また吸水率も大きいのでコンクリートの流動性が低下すると共に凍結融解性に対する耐久性も低く、用途が限定される問題があった。
【０００３】
そこで、吸水率が低く天然骨材に匹敵する強度を有する人工骨材が開発されており、例えば、特願平09-40445号には、骨材中の全鉄量に対する二価の鉄の割合を指標とし、これを一定水準以下に制御することにより発泡を抑制した緻密な人工骨材を製造することが開示されている。また、特開平08-259291号および特開平08-259292号には、焼成雰囲気を酸素濃度あるいは非酸化性雰囲気に制御することによって骨材の発泡を抑制する製造方法が記載されている。さらに、特開平07-206491号には石炭灰の粒度分布を調整することによって天然骨材に匹敵する人工骨材を製造することが記載されている。これらの人工骨材は何れも優れた特性を有し、幅広い用途での利用が期待される。
【０００４】
【発明が解決しようとする課題】
本発明はこれらの人工骨材についても適用できる製造方法に関し、キルンを用いた工業的な実施において、原料を安定に焼成でき、高品質の人工骨材を効率よく安定に製造できる方法およびその人工骨材を提供することを目的とする。
【０００５】
【課題を解決するための手段】
すなわち、本発明は、（１）比重調整材と共に粘結材を配合した石炭灰を用い、そのカルシウム含有量を酸化物換算で２０％以下および未燃炭素量を５％以下とし、これをキルンで焼成してなる非発泡質の人工骨材であって、粘結材として膨潤度１８〜３０cc/2gの粘土鉱物を５〜１０％配合し、かつ、比重調整材として、平均粒径２５μm以下の炭酸カルシウムを原料中のカルシウム含有量が酸化物換算で２０％以下となるように配合した石炭灰を用いたことを特徴とする人工骨材、に関する。
【０００６】
本発明の上記人工骨材は、好ましくは、（２）絶乾比重１．６以上、２４時間吸水率５％以下、および破砕荷重(BS10％)１５トン以上の人工骨材である。
【０００７】
また、本発明は、（３）石炭灰に粘結材を５〜１０％配合し、さらに炭酸カルシウムを原料中のカルシウム含有量が酸化物換算で２０％以下となるように配合し、さらに原料中の未燃炭素量を５％以下とし、これに水を加えて造粒ないし成形した後に、キルンで１２００〜１５００℃に焼成することにより非発泡質の人工骨材を製造する方法であって、粘結材として平均粒径３０μm以下および膨潤度１８〜３０cc/2gの粘土鉱物を用い、比重調整材として平均粒径２５μm以下の炭酸カルシウムを用いることを特徴とする人工骨材の製造方法に関する。
【０００８】
【発明の実施の形態】
以下、本発明を実施形態に即して詳細に説明する。なお、特に示さない限り％は質量％である。
【０００９】
本発明の人工骨材は、比重調整材と共に粘結材を配合した石炭灰を用い、そのカルシウム含有量を酸化物換算で２０％以下および未燃炭素量を５％以下とし、これをキルンで焼成してなる非発泡質の人工骨材であって、粘結材として膨潤度１８〜３０cc/2gの粘土鉱物を５〜１０％配合し、かつ、比重調整材として、平均粒径２５μm以下の炭酸カルシウムを原料中のカルシウム含有量が酸化物換算で２０％以下となるように配合した石炭灰を用いたことを特徴とするものである。
【００１０】
主原料の石炭灰は、火力発電所や石炭焚きボイラーなどから排出されるフライアッシュなどを用いる。この石炭灰の平均粒径は２５μm以下が好ましい。これより平均粒径の大きな石炭灰を用いると造粒した際に、造粒体の強度が低下し、そのためキルン内での転動による擦り減り、や割れが増加して炉内にコーティングが発生し、これが著しいとキルンの停止を頻発するので好ましくない。石炭灰には、必要に応じて、結合材や比重調整材の炭酸カルシウムを配合して用いることができる。
【００１１】
本発明は、焼成原料(石炭灰、または石炭灰と結合材および比重調整材)に含まれるカルシウム量を酸化物(CaO)換算で２０％以下、好ましくは１５％以下に調整して焼成する。酸化カルシウムがこれより過剰に存在すると、目的の物性を得るための焼成温度領域が狭くなり、キルンでの焼成が困難となる。一般にキルンによる焼成では炉内温度が目的の温度に対して±１０℃程度変動するので、目的の物性を得るには、焼成温度について２０℃以上の温度幅を確保する必要がある。この炉内温度が目的の焼成温度域より低いと原料の未焼成部分が多くなり、また炉内温度がこの焼成温度域より高いと焼成による原料粉末の液相部分が多くなり、原料どうしの融着範囲が増大して大きな焼結塊となり、目的の粒径と物性を有する骨材を得ることができない。
ここで、焼成原料中のカルシウム量が酸化物換算で２０％を上回るとこの温度領域が狭くなり、原料粉末どうしの融着または未焼成が頻発して目的の物性を備えた骨材が得られない。また、このカルシウム量が２０％を上回ると骨材の冷却時に熱歪みによる割れを助長したり、骨材にとって有害な水和膨張鉱物であるペリット、ゲーレナイトが生成するので好ましくない。
【００１２】
さらに、焼成原料中の未燃炭素量は５％以下、好ましくは３％以下に調整される。未燃炭素量が５％を超える石炭灰を用いると、キルン操作だけでは石炭灰が焼結軟化域に達するまでに５％以上の未燃炭素を燃焼を完結させるのが困難であるため、石炭灰の焼結温度域に達しても未燃炭素が残留し、この炭素によって鉄が還元され、この還元鉄(FeO)等によって軟化温度が低下して粒子どうしが溶融し、未燃炭素の燃焼によるガス(CO等)が外部に拡散し難くなり、骨材内部に発泡を生じて軽量化する。このため、絶乾比重１.６以上の緻密な骨材を得るのが困難になる。また内部気泡が多いために低強度となり、亀裂を生じ易くなる。
【００１３】
石炭灰に加える粘結材としてベントナイトなどの粘土鉱物を用いることができる。このベントナイトなどは膨潤度１８〜３０cc/2gのものが良く、また添加量は１０％以下が適当である。膨潤度が１８cc/2g未満であると造粒した際に造粒体の強度が低下し、擦減りや割れが増加してキルン内にコーティングが発生し易くなる。膨潤度の値はベントナイト等２ｇに吸収された水の容量である。なお、膨潤度の低いベントナイトでも添加量が多ければ造粒体の強度は向上するが、ベントナイトは水を吸水して糊状になるため、添加量が１０％より多いと造粒体の表面がベト付き、トラブルの原因になる。また添加量が多いとコスト高になる。膨潤度は１８cc/2g以上であれば良いが、膨潤度３０cc/2g以上のものは高価であるので１８〜３０cc/2g程度のものが適当である。
【００１４】
比重調整材として炭酸カルシウムを石炭灰に添加して用いる。炭酸カルシウムを添加することにより骨材の比重を増すことができる。この炭酸カルシウムの添加量は、焼成原料中のカルシウム量が酸化物換算で２０％以下、好ましくは１５％以下となる量である。既に述べたように、焼成原料中のこのカルシウム量が２０％より多いと、目的の物性を得るための焼成温度幅が狭くなり、キルンでの焼成が困難となる。また、焼成後の冷却時に熱歪みによる割れを助長したり、骨材にとって有害な水和膨張鉱物であるペリット、ゲーレナイトが生成するので好ましくない。
【００１５】
また、炭酸カルシウムは平均粒径２５μm以下のものが用いられる。炭酸カルシウムは、焼成下、石炭灰に含まれるシリカやアルミナと反応して焼成鉱物を生成するが、平均粒径が２５μmより大きい粗粒の炭酸カルシウム粒子は反応性が劣り、骨材中に遊離の酸化カルシウムとして残存し、これが水と反応して膨張を起こし、骨材の破壊を招く原因になる場合がある。また、炭酸カルシウム粉末もベントナイトと同様に造粒助材としての効果を有するが、粒度が粗いとバインダーとしての効果も低下する。
【００１６】
以上のように成分を調整した石炭灰を主体とする原料に水を加え、パン型造粒機や成形機によって所望の大きさのペレットに造粒ないし成形し、これをキルンに装入し、１２００〜１５００℃で焼成することにより、発泡を抑制した実質的に非発泡性の人工骨材を製造する。
【００１７】
この製造方法によって、絶乾比重１.６以上、２４時間吸水率５％以下であって破砕荷重(BS10％)１５トン以上の高強度人工骨材を得ることができる。この人工骨材は吸水率が極めて低いので、生コンクリートの流動性が損なわれず、また凍結融解に対して優れた耐久性を有する。更に、絶乾比重が大きく緻密であって破砕荷重(BS10％)が１５トン以上の高強度骨材であるので、土木用コンクリートなどに用いることができる。因みに、現在、市販されている非造粒型軽量骨材のＢＳ１０％破砕荷重は８〜１３トン程度であり、本発明の人工骨材は軽量骨材の範疇に属するものでも１５トン以上の高強度を有している。
【００１８】
【実施例】
以下、本発明を実施例によって具体的に示す。
【００１９】
実施例１
火力発電所から排出された石炭灰(フライアッシュ：平均粒径14.2μm)に炭酸カルシウム(平均粒径6.2μm)とベントナイト(膨潤度21cc/2g)を、表１に示す割合になるように配合し、この混合粉末に水を加えて造粒し、平均粒径１３mmのペレットとした。これをロータリーキルンに入れ、１２４０℃の温度下で９０分間焼成して人工骨材を得た。この人工骨材の絶乾比重および２４時間吸水率を表１にまとめて示した。
表１に示すように、カルシウム含有量(全CaO量)および未燃炭素量を本発明に範囲に調整した試料(No.Ａ〜Ｆ)は何れも絶乾比重が１.７以上であって２４時間吸水率が３％以下、破砕荷重が１５トン以上の高強度人工骨材である。一方、カルシウム含有量ないし未燃炭素量が多い比較試料(No.Ｇ,Ｈ,Ｉ)の破砕荷重は１３トン以下と低く、本発明よりも脆い人工骨材である。
【００２０】
実施例２
火力発電所から排出された石炭灰(フライアッシュ：平均粒径12.9μm)に炭酸カルシウムとベントナイトを、表２、表３に示す割合になるように配合し、この混合粉末に水を加えて造粒し、平均粒径１３mmのペレットとした。これをロータリーキルンに入れ、１２６０℃の温度下で９０分間焼成して人工骨材を得た。この人工骨材の絶乾比重および２４時間吸水率をおのおの表２、表３に示した。この結果に示すように、ベントナイトの添加量と膨潤度が本発明の好適な範囲から外れる試料(NoＬ,NoＭ)は何れも破砕荷重が低く、同様に、炭酸カルシウムの添加量が多い試料(No.Ｐ)と平均粒径が本発明の好適な範囲から外れる試料(NoＱ)も破砕荷重が低い。一方、ベントナイトの添加量と膨潤度、炭酸カルシウムの添加量と平均粒径が本発明の好適な範囲に属する試料(No.Ｊ,Ｋ,Ｎ,Ｏ)は何れも高い破砕荷重と低吸水率を有する高比重の人工骨材である。
【００２１】
【表１】
【表２】
【表３】
【発明の効果】
本発明の製造方法によれば、絶乾比重１.６以上、２４時間吸水率５％以下であって破砕荷重(BS10％)１５トン以上の高強度人工骨材を製造する際に、キルンでの焼成温度の領域が広いので、目的の物性を有する人工骨材を安定に製造することができる。また、この製法によって得られた人工骨材は吸水率が低く、しかも破砕荷重が大きいので、土木等を含む幅広い用途に利用することができる。[0001]
BACKGROUND OF THE INVENTION
In the present invention, it is possible to stably fire in an kiln by adjusting specific components of coal ash for artificial aggregate mainly made of coal ash (fly ash) discharged from a thermal power plant or a coal-fired boiler. In addition, the present invention relates to a method capable of stably producing an artificial aggregate having a relatively large density, high strength, and low water absorption, and the artificial aggregate.
[0002]
[Prior art]
Many artificial aggregates using coal ash as the main raw material and methods for producing the same have been proposed. Many of the production methods are related to porous lightweight aggregates in which the raw coal ash is foamed and expanded during firing to contain a large number of bubbles inside, and such porous lightweight aggregates are generally compressed. Since the strength is weak and the water absorption rate is large, the fluidity of the concrete is lowered, and the durability against freeze-thaw is low.
[0003]
Therefore, artificial aggregates with low water absorption and strength comparable to natural aggregates have been developed.For example, in Japanese Patent Application No. 09-40445, the ratio of divalent iron to the total iron content in aggregates It is disclosed to manufacture a dense artificial bone material in which foaming is suppressed by controlling it to a certain level or less. Japanese Patent Application Laid-Open No. 08-259291 and Japanese Patent Application Laid-Open No. 08-259292 describe a manufacturing method that suppresses foaming of aggregates by controlling the firing atmosphere to an oxygen concentration or a non-oxidizing atmosphere. Further, Japanese Patent Application Laid-Open No. 07-206491 describes that an artificial aggregate comparable to natural aggregate is produced by adjusting the particle size distribution of coal ash. All of these artificial aggregates have excellent characteristics and are expected to be used in a wide range of applications.
[0004]
[Problems to be solved by the invention]
The present invention relates to a production method that can also be applied to these artificial aggregates, and in industrial implementation using a kiln, the raw material can be stably fired, and a high-quality artificial aggregate can be produced efficiently and stably, and the artificial The purpose is to provide aggregate.
[0005]
[Means for Solving the Problems]
That is, the present invention uses (1) coal ash blended with a binder with a specific gravity adjusting material, the calcium content is 20% or less in terms of oxide and the unburned carbon content is 5% or less. A non-foamed artificial aggregate obtained by firing at 5 to 10% of a clay mineral having a swelling degree of 18 to 30 cc / 2 g as a binder , and an average particle size of 25 μm or less as a specific gravity adjusting material. It is related with the artificial aggregate characterized by using the coal ash which mix | blended calcium carbonate in the raw material so that the calcium content in a raw material might be 20% or less in conversion of an oxide .
[0006]
The artificial aggregate of the present invention is preferably an artificial aggregate having (2) an absolute dry specific gravity of 1.6 or more, a 24-hour water absorption rate of 5% or less, and a crushing load (BS 10%) of 15 tons or more.
[0007]
Moreover, this invention mix | blends 5-10% of caking additive to ( 3 ) coal ash, and also mix | blends calcium carbonate so that the calcium content in a raw material may be 20% or less in conversion of an oxide, and also a raw material. A method for producing non-foamed artificial aggregate by setting unburned carbon content in the interior to 5% or less, adding water to this to granulate or form, and then firing at 1200 to 1500 ° C. in a kiln. Further, the present invention relates to a method for producing an artificial bone material, wherein a clay mineral having an average particle size of 30 μm or less and a swelling degree of 18 to 30 cc / 2 g is used as a binder, and calcium carbonate having an average particle size of 25 μm or less is used as a specific gravity adjusting material. .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail according to embodiments. Unless otherwise indicated,% is mass%.
[0009]
The artificial aggregate of the present invention uses coal ash containing a caking additive together with a specific gravity adjusting material, the calcium content is 20% or less in terms of oxide, and the unburned carbon content is 5% or less. A non-foamed artificial aggregate obtained by firing, containing 5 to 10% of clay mineral having a swelling degree of 18 to 30 cc / 2 g as a binder , and having an average particle size of 25 μm or less as a specific gravity adjusting material. Coal ash containing calcium carbonate so that the calcium content in the raw material is 20% or less in terms of oxide is used.
[0010]
As the main raw material coal ash, fly ash discharged from thermal power plants or coal-fired boilers is used. The average particle diameter of the coal ash is preferably 25 μm or less. If coal ash with a larger average particle size is used, the strength of the granulated material will be reduced when granulated, so it will be worn away by rolling in the kiln, and cracks will increase, resulting in coating in the furnace. However, if this is significant, the kiln stops frequently, which is not preferable. Coal ash can be used by blending calcium carbonate, which is a binder or specific gravity adjusting material, as necessary.
[0011]
In the present invention, the amount of calcium contained in the firing raw material (coal ash or coal ash and binder and specific gravity adjusting material) is adjusted to 20% or less, preferably 15% or less in terms of oxide (CaO), and fired. If calcium oxide is present in an excessive amount, the firing temperature range for obtaining the desired physical properties becomes narrow, and firing in the kiln becomes difficult. In general, in the kiln firing, the furnace temperature fluctuates by about ± 10 ° C. with respect to the target temperature. Therefore, in order to obtain the desired physical properties, it is necessary to secure a temperature range of 20 ° C. or higher for the firing temperature. If this furnace temperature is lower than the target firing temperature range, there will be more unfired parts of the raw material, and if the furnace temperature is higher than this firing temperature range, the liquid phase part of the raw material powder will be increased due to firing, and the raw materials will melt. The wearing range is increased to form a large sintered mass, and an aggregate having the desired particle size and physical properties cannot be obtained.
Here, when the amount of calcium in the fired raw material exceeds 20% in terms of oxide, this temperature range becomes narrower, and fusion or unfired of the raw material powders frequently occurs to obtain an aggregate having the desired physical properties. Absent. On the other hand, when the calcium content exceeds 20%, cracking due to thermal strain is promoted during cooling of the aggregate, and peritite and gehlenite, which are hydrated expansion minerals harmful to the aggregate, are not preferable.
[0012]
Further, the amount of unburned carbon in the calcined raw material is adjusted to 5% or less, preferably 3% or less. If coal ash with an unburned carbon content exceeding 5% is used, it is difficult to complete combustion of 5% or more of unburned carbon by the kiln operation alone until the coal ash reaches the sintering softening zone. Even if it reaches the sintering temperature range of ash, unburned carbon remains, iron is reduced by this carbon, softening temperature is lowered by this reduced iron (FeO) etc., particles are melted, and unburned carbon burns Gas (CO, etc.) due to is difficult to diffuse to the outside and foams inside the aggregate to reduce the weight. For this reason, it becomes difficult to obtain a dense aggregate having an absolute dry specific gravity of 1.6 or more. Moreover, since there are many internal bubbles, it becomes low intensity | strength and it becomes easy to produce a crack.
[0013]
Clay minerals such as bentonite can be used as a caking additive to be added to coal ash. This bentonite or the like should have a swelling degree of 18 to 30 cc / 2 g, and the addition amount is suitably 10% or less. When the degree of swelling is less than 18 cc / 2 g, the strength of the granulated product is reduced when granulated, and abrasion and cracking increase to easily cause coating in the kiln. The value of the degree of swelling is the volume of water absorbed by 2 g of bentonite or the like. Even if bentonite has a low degree of swelling, the strength of the granule improves if the added amount is large. However, since bentonite absorbs water and becomes paste-like, if the added amount is more than 10%, the surface of the granulated body is increased. Sticky and cause trouble. Moreover, when there is much addition amount, cost will become high. The degree of swelling may be 18 cc / 2g or more, but those having a degree of swelling of 30 cc / 2g or more are expensive, so those of about 18-30 cc / 2g are suitable.
[0014]
Calcium carbonate is added to coal ash as a specific gravity adjusting material . The specific gravity of the aggregate can be increased by adding calcium carbonate. The amount of calcium carbonate added is such that the amount of calcium in the fired raw material is 20% or less, preferably 15% or less in terms of oxide. As already described, if the amount of calcium in the firing raw material is more than 20%, the firing temperature range for obtaining the desired physical properties becomes narrow, and firing in the kiln becomes difficult. Further, it is not preferable because it promotes cracking due to thermal strain during cooling after firing, or perit and gehlenite, which are hydrated expansion minerals harmful to aggregates.
[0015]
In addition, calcium carbonate having an average particle size of 25 μm or less is used . Calcium carbonate reacts with silica and alumina contained in coal ash during firing to produce calcined minerals, but coarse calcium carbonate particles with an average particle size greater than 25 μm are inferior in reactivity and are released into the aggregate. This may remain as calcium oxide, which may react with water to cause expansion and cause aggregate destruction. Calcium carbonate powder also has an effect as a granulating aid like bentonite, but if the particle size is coarse, the effect as a binder also decreases.
[0016]
Water is added to the raw material mainly composed of coal ash with the components adjusted as described above, granulated or molded into pellets of a desired size by a bread granulator or molding machine, and this is charged into a kiln, By baking at 1200-1500 degreeC, the substantially non-foaming artificial bone material which suppressed foaming is manufactured.
[0017]
By this production method, a high-strength artificial bone material having an absolute dry specific gravity of 1.6 or more, a 24-hour water absorption of 5% or less, and a crushing load (BS 10%) of 15 tons or more can be obtained. Since this artificial aggregate has a very low water absorption rate, the fluidity of ready-mixed concrete is not impaired, and it has excellent durability against freezing and thawing. Furthermore, it is a high-strength aggregate with a large absolute dry specific gravity and a fine crushing load (BS 10%) of 15 tons or more, so it can be used for civil engineering concrete. Incidentally, the BS 10% crushing load of the non-granulated light aggregate currently on the market is about 8 to 13 tons, and the artificial aggregate of the present invention has a high value of 15 tons or more even if it belongs to the category of lightweight aggregate. Has strength.
[0018]
【Example】
Hereinafter, the present invention will be specifically described by way of examples.
[0019]
Example 1
Coal ash discharged from a thermal power plant (fly ash: average particle size 14.2μm) and calcium carbonate (average particle size 6.2μm) and bentonite (swelling degree 21cc / 2g) are blended in the proportions shown in Table 1. Then, water was added to the mixed powder and granulated to obtain pellets having an average particle diameter of 13 mm. This was put into a rotary kiln and fired at a temperature of 1240 ° C. for 90 minutes to obtain an artificial aggregate. The absolute dry specific gravity and 24-hour water absorption rate of this artificial aggregate are summarized in Table 1.
As shown in Table 1, all of the samples (No. A to F) in which the calcium content (total CaO amount) and the unburned carbon amount were adjusted within the range of the present invention had an absolute dry specific gravity of 1.7 or more. It is a high-strength artificial aggregate with a 24-hour water absorption rate of 3% or less and a crushing load of 15 tons or more. On the other hand, the crushing load of the comparative sample (No. G, H, I) having a large amount of calcium or unburned carbon is as low as 13 tons or less, and is a brittle artificial bone than the present invention.
[0020]
Example 2
Coal ash (fly ash: average particle size 12.9μm) discharged from a thermal power plant is blended with calcium carbonate and bentonite in the proportions shown in Tables 2 and 3, and water is added to this mixed powder. The pellets were made into pellets having an average particle diameter of 13 mm. This was put into a rotary kiln and fired at a temperature of 1260 ° C. for 90 minutes to obtain an artificial aggregate. Tables 2 and 3 show the absolute dry gravity and 24-hour water absorption rate of the artificial aggregate. As shown in this result, the samples (NoL, NoM) in which the addition amount and swelling degree of bentonite deviate from the preferred range of the present invention have a low crushing load, and similarly, the samples (No .P) and the sample (NoQ) whose average particle size is outside the preferred range of the present invention also has a low crushing load. On the other hand, the samples (No. J, K, N, O) in which the added amount and swelling degree of bentonite, the added amount of calcium carbonate and the average particle diameter belong to the preferred range of the present invention are all high crushing load and low water absorption rate. It is a high specific gravity artificial bone having
[0021]
[Table 1]
[Table 2]
[Table 3]
【The invention's effect】
According to the production method of the present invention, when producing a high strength artificial aggregate having an absolute dry specific gravity of 1.6 or more, a 24-hour water absorption of 5% or less, and a crushing load (BS 10%) of 15 tons or more, Since the range of the firing temperature is wide, an artificial aggregate having the desired physical properties can be stably produced. Moreover, since the artificial aggregate obtained by this manufacturing method has a low water absorption rate and a large crushing load, it can be used for a wide range of applications including civil engineering.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34012499A JP4509269B2 (en) | 1999-11-30 | 1999-11-30 | Artificial aggregate and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34012499A JP4509269B2 (en) | 1999-11-30 | 1999-11-30 | Artificial aggregate and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001158649A JP2001158649A (en) | 2001-06-12 |
| JP4509269B2 true JP4509269B2 (en) | 2010-07-21 |
Family
ID=18333963
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34012499A Expired - Fee Related JP4509269B2 (en) | 1999-11-30 | 1999-11-30 | Artificial aggregate and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4509269B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AUPR507201A0 (en) * | 2001-05-16 | 2001-06-07 | Unisearch Limited | Concrete aggregate |
| JP3864762B2 (en) * | 2001-11-12 | 2007-01-10 | 宇部興産株式会社 | Concrete composition and mortar composition |
| JP6306919B2 (en) * | 2013-10-31 | 2018-04-04 | 太平洋セメント株式会社 | Cement additive and cement composition |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3326571B2 (en) * | 1993-11-30 | 2002-09-24 | 太平洋セメント株式会社 | Method for producing artificial aggregate from coal ash, artificial aggregate, and concrete using the same |
| JP3369687B2 (en) * | 1993-12-24 | 2003-01-20 | 太平洋セメント株式会社 | Fly ash artificial aggregate |
| JPH08259292A (en) * | 1995-03-23 | 1996-10-08 | Chichibu Onoda Cement Corp | Production of fly ash type artificial aggregate |
| JP3623021B2 (en) * | 1995-07-26 | 2005-02-23 | 太平洋セメント株式会社 | Artificial aggregate and method for producing the same |
| JPH10194804A (en) * | 1997-01-14 | 1998-07-28 | Sumitomo Metal Mining Co Ltd | Manufacturing method of artificial aggregate |
-
1999
- 1999-11-30 JP JP34012499A patent/JP4509269B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2001158649A (en) | 2001-06-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EA023830B1 (en) | Method for producing an agglomerate made of fine material containing metal oxide for use as a blast furnace feed material | |
| EP0188371A2 (en) | Artificial lightweight aggregate | |
| JP2001163647A (en) | Method for producing artificial aggregate using waste incineration ash and artificial aggregate obtained by this method | |
| JP2005320188A (en) | Inorganic foam fired body and method for producing the same | |
| JPH0977543A (en) | Artificial lightweight aggregate and its production | |
| JP2000143307A (en) | Method for producing artificial lightweight aggregate and artificial lightweight aggregate obtained by this method | |
| JP4509269B2 (en) | Artificial aggregate and method for producing the same | |
| KR100186278B1 (en) | Light weight agregate using stone dust sludge and paper sluge and method for preparing the same | |
| JPH04119952A (en) | Production of artificial light aggregate | |
| KR100392933B1 (en) | Composition for lightweight aggregate | |
| KR20000072111A (en) | Composition for lightweight aggregate and method for manufacturing the same | |
| JP3623021B2 (en) | Artificial aggregate and method for producing the same | |
| JP2001163646A (en) | Artificial aggregate using coal ash as main raw material and producing method thereof | |
| KR20020044899A (en) | Composition for lightweight aggregate and method for manufacturing the same | |
| JP3267152B2 (en) | Manufacturing method of coal ash lightweight aggregate | |
| JP3165626U (en) | Foam glass spherical particles | |
| JP4377256B2 (en) | Manufacturing method of artificial lightweight aggregate | |
| JP2005104804A (en) | Artificial aggregate | |
| JP3369687B2 (en) | Fly ash artificial aggregate | |
| JP3624033B2 (en) | Artificial lightweight aggregate | |
| JPH07206491A (en) | Method for producing artificial aggregate using coal ash, artificial aggregate, and concrete using the same | |
| JPH08259292A (en) | Production of fly ash type artificial aggregate | |
| JP3121846B2 (en) | Manufacturing method of lightweight aggregate | |
| JP2006298730A (en) | Method of firing incineration ash and sintered compact obtained by the same method | |
| JPH10251048A (en) | Production of artificial fly ash aggregate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20061129 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20070816 |
|
| A711 | Notification of change in applicant |
Free format text: JAPANESE INTERMEDIATE CODE: A712 Effective date: 20071010 |
|
| RD02 | Notification of acceptance of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7422 Effective date: 20071010 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20071010 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20090312 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20091117 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100118 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100309 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100405 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20100427 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20100428 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130514 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4509269 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140514 Year of fee payment: 4 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |