JPH0118027B2 - - Google Patents
Info
- Publication number
- JPH0118027B2 JPH0118027B2 JP3983383A JP3983383A JPH0118027B2 JP H0118027 B2 JPH0118027 B2 JP H0118027B2 JP 3983383 A JP3983383 A JP 3983383A JP 3983383 A JP3983383 A JP 3983383A JP H0118027 B2 JPH0118027 B2 JP H0118027B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- melting
- incineration ash
- crystallization
- 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
Links
- 238000002425 crystallisation Methods 0.000 claims description 18
- 230000008025 crystallization Effects 0.000 claims description 18
- 239000000203 mixture Substances 0.000 claims description 17
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 8
- 239000012768 molten material Substances 0.000 claims description 6
- 230000035939 shock Effects 0.000 claims description 6
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 238000010309 melting process Methods 0.000 claims description 3
- 238000002844 melting Methods 0.000 description 27
- 230000008018 melting Effects 0.000 description 27
- 238000004056 waste incineration Methods 0.000 description 19
- 238000000034 method Methods 0.000 description 14
- 239000013078 crystal Substances 0.000 description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 8
- 230000000694 effects Effects 0.000 description 8
- 239000000155 melt Substances 0.000 description 8
- 239000011521 glass Substances 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000007789 gas Substances 0.000 description 5
- 239000002245 particle Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910052681 coesite Inorganic materials 0.000 description 3
- 229910052906 cristobalite Inorganic materials 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000010801 sewage sludge Substances 0.000 description 3
- 239000000377 silicon dioxide Substances 0.000 description 3
- 235000012239 silicon dioxide Nutrition 0.000 description 3
- 229910052682 stishovite Inorganic materials 0.000 description 3
- 229910052905 tridymite Inorganic materials 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 239000002667 nucleating agent Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000003303 reheating Methods 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 239000010865 sewage Substances 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 238000013112 stability test Methods 0.000 description 2
- 241000975357 Salangichthys microdon Species 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000012669 compression test Methods 0.000 description 1
- 239000000112 cooling gas Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 229910000514 dolomite Inorganic materials 0.000 description 1
- 239000010459 dolomite Substances 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000007496 glass forming Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
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
- C04B18/026—Melted materials
-
- 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
- C04B18/04—Waste materials; Refuse
- C04B18/06—Combustion residues, e.g. purification products of smoke, fumes or exhaust gases
- C04B18/10—Burned or pyrolised refuse
- C04B18/108—Burned or pyrolised refuse involving a melting step
-
- 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)
- Ceramic Engineering (AREA)
- Civil Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Environmental & Geological Engineering (AREA)
- Combustion & Propulsion (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Description
（産業上の利用分野）
本発明は下水汚泥焼却灰や都市ごみ焼却灰等の
廃棄物焼却灰を原料とする骨材の製造法に関する
ものである。
（従来技術）
従来、各地の下水処理場やごみ処理場から発生
する下水汚泥やごみはそのまま埋立投棄すると衛
生上あるいは悪臭公害上問題があるので大部分は
焼却処理され、焼却灰として埋立投棄されている
が、埋立用地の確保が難しくなつてきているうえ
に焼却灰からの重金属等の溶出、その他埋立処分
にともなう二次公害が大きな社会問題となつてお
り、さらに省資源、省エネルギーの観点からも廃
棄物焼却灰を溶融して有効利用することが検討さ
れている。廃棄物焼却灰を溶融して骨材等に有効
利用しようとする試みとしては、特公昭55−
24010号公報に示されるように溶融物を水封ボツ
クス中に落下させて水中固化させて小塊状のガラ
ス質の骨材を得る方法があるが、この方法によつ
て得られるガラス質骨材は強度が弱い上に化学的
安定性に欠けるという問題を有しており、また、
鋳型中に溶融物を投入し結晶化させることにより
大塊状の完全結晶化物を得たのち破砕して骨材を
得る方法は結晶化に多大の熱量を必要とするうえ
に大規模な機械的破砕装置が必要でコスト高とな
る等の問題点を有するものであつた。
（発明の目的）
本発明は前記のような問題点を解決して機械的
強度および化学的安定性に優れ、しかも、用途に
合致した粒度分布の骨材を安価にかつ極めて容易
に量産できる廃棄物焼却灰を原料とする骨材の製
造法を目的として完成されたものである。
（発明の構成）
本発明は主たる組成がSiO225〜45％（重量％、
以下同じ）、Al2O35〜15％、Fe2O35〜25％、
CaO20〜40％、MgO1〜５％、P2O53〜15％の範
囲内でかつ（CaO＋MgO）／SiO2の比を0.8〜1.2
に組成調整した廃棄物焼却灰を1350〜1500℃で溶
融し、この溶融物を急冷して熱衝撃破砕したのち
前記溶融工程で発生した排ガスを循環させた結晶
化炉中において800℃以上1000℃未満に20分以上
保持して結晶化することを特徴とするものであ
る。
本発明において原料となる廃棄物焼却灰は下水
汚泥焼却灰あるいは都市ごみ焼却灰等であつて、
これらの廃棄物焼却灰中にはSiO2、Al2O3、
Fe2O3、CaO、MgO、P2O5の外にK2O、Na2O等
が主に含まれており、それらの含有量は焼却灰の
種類等により若干異なる。このような廃棄物焼却
灰の溶融特性すなわち溶融温度に対する粘度の関
係をみると、一般のガラスの成形加工に適した粘
度域に対応する成形温度域は一般のガラスに比較
して極端に狭く、いわゆる「足の短いガラス」の
性質を有しており、また、例えば1350℃以上の溶
融温度域における粘度は一般のガラスに比較して
かなり低いことから溶融したのち該溶融炉の炉底
より自然流下させるのに適しているが、このよう
な組成の廃棄物焼却灰を溶融後破砕し半結晶化し
て骨材にするには、SiO225〜45％好ましくは30
〜40％、Al2O35〜15％好ましくは５〜10％、
Fe2O35〜25％好ましくは５〜15％、CaO20〜40
％好ましくは30〜35％、MgO1〜５％好ましくは
２〜５％、P2O53〜15％好ましくは５〜12％の範
囲内でかつ（CaO＋MgO）／SiO2比が0.8〜1.2好
ましくは0.9〜1.1の範囲内であることが重要であ
り、このために焼却炉より得られた前記廃棄物焼
却灰はこれを分析し、組成範囲が前記特定組成範
囲内にないときは、前記の組成範囲に入るように
調整する。なお、組成調整に際しては安価な粘
土、シラス、ベンガラ、石炭、ドロマイト、骨灰
を用いることが好ましい。このようにして組成調
整された廃棄物焼却灰は溶融炉中において1350〜
1500℃程度で溶融し、この溶融物を該溶融炉の炉
底より自然流下させるのに必要な粘度例えば101
ポイズ以下好しくは101/2ポイズ以下の粘度に維持
しながらこれを溶融炉の湯口より最終骨材粒度に
応じた径たとえば直径が３〜10mm程度の棒状もし
くは糸状流下溶融物となるように流下させ、該流
下溶融物に噴霧水を吹付けて冷却したり、冷却気
体を吹付けたりして熱衝撃破砕を行い、引きつづ
いて該破砕物を溶融炉排ガスを循環させた結晶化
炉中において800℃以上1000℃未満好ましくは850
〜950℃の温度範囲の所定温度に20分以上好まし
くは40分以上加熱保持して該破砕物中に結晶核の
形成およびその結晶核を中心として結晶化率が20
〜80％好ましくは40〜60％となるよう部分的に結
晶成長を起こさせる。このようにして得られた粒
状の結晶化物は前工程の熱衝撃破砕により既に破
砕されているから、そのまま或いは分級して製品
とされるもので、製品化までの一連の工程は大幅
に簡略化されることとなる。なお、本発明におい
てSiO2を25〜45％とするのはSiO2が25％未満で
はガラス形成骨格としてのSiO2が不足して高強
度の結晶化物が得られないからであり、45％を越
えると溶融温度が上昇して前記溶融温度では粘度
が高くなつて該溶融物の該炉底からの自然流下が
難しくなるうえ部分的に結晶化させるうえにも悪
影響を及ぼすからであり、また、Al2O3を５〜15
％とするのはAl2O3が５％未満では高強度の結晶
化物が得られず、15％を越えると溶融温度が高く
なりすぎるからであり、さらに、Fe2O3を５〜25
％とするのはFe2O3は融剤としてばかりでなく核
形成剤としても重要な成分であり、その量が５％
未満では融剤としての効果がうすれて溶融温度が
低下しないうえに結晶核の形成も不充分であり、
25％を越えると強度も著しく低下させるからであ
る。また、CaOを20〜40％とするのはCaOが20％
未満では溶融物の粘度が増加するとともに結晶化
に悪影響があるうえ強度が低下し、40％を越える
と化学的安定性を著しく低下させるからであり、
さらに、MgOを１〜５％とするのは、MgOは
CaOに代わる組成調整剤として用いられていて、
化学的安定性を増す効果があるのも拘らずその含
有量が１％未満ではその効果がなく、５％を越え
る量を入れても効果は変らないからであり、ま
た、P2O5を３〜15％とするのはP2O5は核形成剤
として最も重要な成分であつて、その量が３％未
満では800℃以上1000℃未満の温度範囲では結晶
化が起こりにくく、また15％を越えると強度低下
を来たし好ましくない。さらにまた、（CaO＋
MgO）／SiO2比を0.8〜1.2とすることは溶融温度
の低下のために重要であるうえに溶融物の結晶化
のためにも重要であつて、この混合物が0.8未満
あるいは1.2を越えると溶融温度が上昇して溶融
炉の炉材の侵蝕や溶融コストの増加が起るので好
ましくない。次に、廃棄物焼却灰の溶融温度を
1350〜1500℃と限定したのは前記組成範囲に調整
された廃棄物焼却灰の溶融物は溶融温度が高くな
ると急激に粘性が低下するいわゆる「足の短いガ
ラス」の性質を有することから、1350℃未満では
溶融炉の湯口から溶融物を流下させるのに必要な
粘度101ポイズ以下好ましくは101/2ポイズ以下の
粘度が得られないため流下溶融物の径が大きくな
つて熱衝撃破砕が充分に行われず、後工程で再度
破砕工程が必須となるからで、また、実プラント
において1500℃を越える溶融温度を維持すること
は設備上からもエネルギーコスト面からもロスが
大きいので上限を1500℃とし、熱破砕後の結晶化
工程において、1350〜1500℃の溶融工程で発生す
る排ガスを結晶化炉中に循環すると、結晶化炉に
おける追焚きはほとんどいらなくなるから800〜
1000℃の温度で熱処理するには溶融温度を1350〜
1500℃の温度範囲に保持することが熱エネルギー
の有効利用の点より最もよい。また、結晶化温度
を800℃以上1000℃未満と限定したのは前記組成
に調整された廃棄物焼却灰は800℃未満では結晶
核形成および結晶成長が起りにくく、1000℃以上
では溶融工程で発生する排ガスを循環するだけで
はこの温度を保持する事が困難で追焚きが必要と
なり、更には結晶成長が進んで分級工程後必要に
応じて設けられる破砕工程において破砕しにくく
なることからである。なお、結晶化に際してはそ
れぞれ特定温度範囲内の一定温度に所定時間保持
するのが均一な結晶核の形成および結晶成長をさ
せるうえでより好ましいが、それぞれの特定温度
範囲内で所定時間かけてゆつくりと降温あるいは
昇温をしてもほぼ同等の結果が得られる。また、
結晶化時間を20分以上としたのは、20分未満の保
持時間では結晶量が少なくて必要とする結晶化を
行うことができないので、所望の強度の結晶化骨
材が得られないためである。このようにして得ら
れる骨材は溶融物を直接水砕することによつて得
られるガラス質骨材に比較して高い強度を有し、
しかも、溶融物を高温で結晶化することによつて
完全結晶化された骨材に比較してエネルギーが大
幅に節減できるため骨材製造コストが低く、しか
も、予め熱破砕することによつて粒状化されてく
るので破砕コストは低減し、結晶化後は殆んど分
級のみで骨材を得ることができる。
（発明の効果）
本発明は以上の説明によつて明らかなように、
廃棄物焼却灰を特定の温度で溶融後熱衝撃破砕し
て細粒状とし、しかる後に溶融炉排ガスを循環さ
せて排熱を有効利用した結晶化炉中において保持
させておくことによつて従来の大塊状の完全結晶
化物を機械破砕により細粒化する場合に比べて燃
料代並びに破砕コストが大幅に節減され、トータ
ルコストで50〜60％のコストダウンも可能となる
うえに粒径も溶融物の流下太さと噴霧水量を調整
するだけで任意の粒度分布とすることができる利
点がある。しかも、本発明によつて得られた骨材
は従来のガラス質の骨材に比べて化学的安定性並
びに機械的強度に優れており、骨材としての性能
並びにコンクリート試験における川砂との比較試
験においても何ら遜色がない事が確認され、従来
埋立処分されてきた廃棄物焼却灰の埋立処分地や
二次公害の心配をなくすことができる等種々の利
点があり、従来の廃棄物焼却灰の処理上の問題点
を解決した産業廃棄物を原料とする骨材の製造法
として産業上極めて有用なものである。
（実施例）
各所の下水処理場の廃棄物焼却灰を下記表に記
載する化学組成および組成比率に組成調整し、そ
れぞれの溶融特性に従つて1380〜1480℃の温度に
維持された溶融炉内において５時間で溶融し、そ
の溶融物の粘度を101/2ポイズ以下に維持しながら
溶融炉の湯口より５〜８mmφの棒状にて流下させ
た。該流下溶融物に噴霧水を３〜５／min吹付
けて急冷して熱衝撃破砕を行ない、引きつづき該
破砕物を溶融炉排ガスを循環させた結晶化炉中に
おいて850〜950℃に40分以上保持して部分的に結
晶化し、これを所定粒径に分級して得た骨材No.１
〜No.９を表−に本発明例として記載した。次に
本発明の数値限定範囲外の組成および熱処理条件
で得られた骨材No.10〜No.15を参考例として記載し
た。さらに以上の様にして製造された骨材を用い
てJIS規格に準じコンクリート強度試験を行つた
結果を本発明の数値限定外の骨材並びに川砂との
対比において表−に記載した。この結果から明
らかなように、本発明によつて得られた骨材は参
考例によつて得られた骨材に比べて機械的強度お
よび化学的安定性に優れていることが確認され
た。
(Field of Industrial Application) The present invention relates to a method for producing aggregate using waste incineration ash such as sewage sludge incineration ash and municipal waste incineration ash as a raw material. (Prior art) Conventionally, sewage sludge and garbage generated from sewage treatment plants and garbage treatment plants in various places have been incinerated and disposed of as incinerated ash in landfills, since dumping them directly in landfills poses hygiene and odor pollution problems. However, it is becoming difficult to secure land for landfills, and the elution of heavy metals from incinerated ash and other secondary pollution associated with landfill disposal have become major social problems. The effective use of waste incineration ash by melting it is also being considered. An attempt was made to melt waste incineration ash and use it effectively as aggregate, etc.
As shown in Publication No. 24010, there is a method of dropping a molten material into a water-sealed box and solidifying it in water to obtain small-sized glass aggregates, but the glass aggregates obtained by this method are It has the problems of low strength and lack of chemical stability, and
This method requires a large amount of heat for crystallization and requires large-scale mechanical crushing. This method had problems such as requiring equipment and increasing costs. (Purpose of the Invention) The present invention solves the above-mentioned problems and provides a waste disposal method that allows mass production of aggregate with excellent mechanical strength and chemical stability, and a particle size distribution that matches the intended use at a low cost. This method was developed for the purpose of producing aggregates using ash from incineration. (Structure of the invention) The main composition of the present invention is SiO 2 25 to 45% (wt%,
(same below), Al 2 O 3 5-15%, Fe 2 O 3 5-25%,
Within the range of CaO20-40%, MgO1-5%, P2O5 3-15 % and the ratio of (CaO + MgO)/SiO2 0.8-1.2
Waste incineration ash whose composition has been adjusted to It is characterized by crystallization after being held for 20 minutes or more. The waste incineration ash used as a raw material in the present invention is sewage sludge incineration ash or municipal waste incineration ash, etc.
These waste incineration ash contains SiO 2 , Al 2 O 3 ,
In addition to Fe 2 O 3 , CaO, MgO, and P 2 O 5 , it mainly contains K 2 O, Na 2 O, etc., and their content varies slightly depending on the type of incineration ash. Looking at the melting characteristics of waste incineration ash, that is, the relationship between viscosity and melting temperature, the forming temperature range corresponding to the viscosity range suitable for forming ordinary glass is extremely narrow compared to ordinary glass. It has the properties of so-called "short-legged glass," and its viscosity in the melting temperature range of 1,350°C or higher is considerably lower than that of ordinary glass. Suitable for flowing down, but in order to melt and then crush waste incineration ash with such a composition and semi-crystallize it into aggregate, SiO 2 25-45%, preferably 30
~40%, Al2O3 5-15 % preferably 5-10%,
Fe 2 O 3 5-25% preferably 5-15%, CaO20-40
% preferably 30-35%, MgO 1-5% preferably 2-5%, P2O5 3-15 % preferably 5-12% and (CaO + MgO)/ SiO2 ratio preferably 0.8-1.2. It is important that the ash is within the range of 0.9 to 1.1, and for this reason, the waste incineration ash obtained from the incinerator is analyzed, and if the composition range is not within the specific composition range, the above-mentioned Adjust to fall within the composition range. In addition, when adjusting the composition, it is preferable to use inexpensive clay, whitebait, red iron, coal, dolomite, and bone ash. The waste incineration ash whose composition has been adjusted in this way is
The viscosity required for melting at approximately 1500°C and allowing the molten material to flow down by gravity from the bottom of the melting furnace is, for example, 10 1
While maintaining the viscosity at less than poise, preferably less than 10 1/2 poise, the melt is poured from the sprue of the melting furnace into a rod-like or filament-like melt with a diameter corresponding to the final aggregate particle size, for example, about 3 to 10 mm in diameter. The falling molten material is cooled by spraying water or cooling gas to perform thermal shock crushing, and then the crushed material is placed in a crystallization furnace in which melting furnace exhaust gas is circulated. 800℃ or more and less than 1000℃, preferably 850℃
By heating and holding at a predetermined temperature in the temperature range of ~950°C for 20 minutes or more, preferably 40 minutes or more, crystal nuclei are formed in the crushed material and the crystallization rate is 20% centered around the crystal nuclei.
Partial crystal growth is caused to reach ~80%, preferably 40-60%. The granular crystallized material obtained in this way has already been crushed by thermal shock crushing in the previous process, so it can be made into a product as it is or after being classified, which greatly simplifies the series of steps to commercialize it. It will be done. In addition, in the present invention, SiO 2 is set to 25 to 45% because if SiO 2 is less than 25%, SiO 2 as a glass-forming skeleton is insufficient and a high-strength crystallized product cannot be obtained. If it exceeds the temperature, the melting temperature will rise, and the viscosity will increase at the melting temperature, making it difficult for the melt to flow down naturally from the bottom of the furnace, and also having an adverse effect on partially crystallizing it. 5-15 Al 2 O 3
% because if Al 2 O 3 is less than 5%, a high-strength crystallized product cannot be obtained, and if it exceeds 15%, the melting temperature becomes too high.
% because Fe 2 O 3 is an important component not only as a fluxing agent but also as a nucleating agent, and its amount is 5%.
If it is less than that, the effect as a flux will be weakened and the melting temperature will not be lowered, and the formation of crystal nuclei will be insufficient.
This is because if it exceeds 25%, the strength will be significantly reduced. Also, CaO is 20% to 40%.
If it is less than 40%, the viscosity of the melt will increase, which will have a negative effect on crystallization and the strength will decrease, and if it exceeds 40%, the chemical stability will be significantly reduced.
Furthermore, setting MgO to 1 to 5% means that MgO is
It is used as a composition adjusting agent in place of CaO,
This is because although it has the effect of increasing chemical stability, it has no effect if the content is less than 1%, and the effect remains unchanged even if it is added in an amount exceeding 5 % . The reason why it is set at 3 to 15% is because P 2 O 5 is the most important component as a nucleating agent, and if its amount is less than 3%, crystallization is difficult to occur in the temperature range of 800°C or higher and lower than 1000°C. If it exceeds %, the strength will decrease, which is not preferable. Furthermore, (CaO+
Setting the MgO)/SiO2 ratio between 0.8 and 1.2 is important not only for lowering the melting temperature but also for crystallizing the melt; if this mixture is less than 0.8 or more than 1.2, This is undesirable because the melting temperature rises, causing corrosion of the furnace material of the melting furnace and an increase in melting costs. Next, the melting temperature of waste incineration ash is
The reason why the temperature was limited to 1350 to 1500°C was because the molten waste incineration ash adjusted to the above composition range has the property of so-called "short-legged glass" in which the viscosity decreases rapidly as the melting temperature increases. If the temperature is below ℃, it will not be possible to obtain a viscosity of 10 1 poise or less, preferably 10 1/2 poise or less, which is necessary for the melt to flow down from the sprue of the melting furnace, so the diameter of the flowing melt will increase and thermal shock fracture will occur. This is because the crushing process is not carried out sufficiently and the crushing process is required again in the subsequent process.Also, maintaining a melting temperature over 1500℃ in an actual plant causes a large loss from both equipment and energy cost perspectives, so the upper limit should be set at 1500℃. ℃, and in the crystallization process after thermal crushing, if the exhaust gas generated in the melting process at 1350 to 1500℃ is circulated through the crystallization furnace, reheating in the crystallization furnace is almost unnecessary, so the temperature is 800 to 800℃.
For heat treatment at a temperature of 1000℃, the melting temperature must be 1350~
It is best to maintain the temperature within the 1500°C range in terms of effective use of thermal energy. In addition, the crystallization temperature was limited to 800°C or more and less than 1000°C because waste incineration ash adjusted to the above composition is difficult to form crystal nuclei and grow when it is below 800°C, and when it is above 1000°C, crystallization occurs during the melting process. This is because it is difficult to maintain this temperature by simply circulating the exhaust gas, which necessitates reheating, and furthermore, crystal growth progresses, making it difficult to crush in the crushing process that is provided as necessary after the classification process. In addition, during crystallization, it is more preferable to hold each temperature at a constant temperature within a specific temperature range for a predetermined period of time in order to form uniform crystal nuclei and grow crystals. Almost the same results can be obtained by changing the structure and lowering or increasing the temperature. Also,
The reason why the crystallization time was set to 20 minutes or more was because if the holding time was less than 20 minutes, the amount of crystals would be small and the necessary crystallization could not be performed, so a crystallized aggregate with the desired strength could not be obtained. be. The aggregate obtained in this way has higher strength than the glassy aggregate obtained by directly crushing the melt,
Moreover, by crystallizing the molten material at high temperatures, energy is significantly saved compared to completely crystallized aggregates, resulting in lower aggregate manufacturing costs. The crushing cost is reduced, and after crystallization, aggregate can be obtained almost only by classification. (Effects of the Invention) As is clear from the above description, the present invention has the following effects:
By melting the waste incineration ash at a specific temperature, thermal shock crushing it into fine particles, and then holding it in a crystallization furnace that circulates the melting furnace exhaust gas and effectively utilizes the exhaust heat, Compared to mechanically crushing a large block of completely crystallized material into fine particles, fuel costs and crushing costs are significantly reduced, making it possible to reduce the total cost by 50 to 60%. It has the advantage that any particle size distribution can be achieved by simply adjusting the thickness of the flow and the amount of water sprayed. In addition, the aggregate obtained by the present invention has superior chemical stability and mechanical strength compared to conventional glassy aggregates, and its performance as an aggregate and comparison test with river sand in concrete tests It has been confirmed that there is no inferiority to conventional waste incineration ash, and there are various advantages such as eliminating the need for landfill sites and secondary pollution for waste incineration ash, which has traditionally been disposed of in landfills. This method is extremely useful industrially as a method for producing aggregates from industrial waste that solves processing problems. (Example) Waste incineration ash from sewage treatment plants in various locations was adjusted to the chemical composition and composition ratio listed in the table below, and was placed in a melting furnace maintained at a temperature of 1380 to 1480°C according to the respective melting characteristics. The melt was melted in 5 hours, and the molten material was flowed down from the sprue of the melting furnace in a rod shape of 5 to 8 mm diameter while maintaining the viscosity of the melt at 10 1/2 poise or less. The falling melt is rapidly cooled by spraying water at 3 to 5 minutes per minute to perform thermal shock crushing, and then the crushed material is heated to 850 to 950°C for 40 minutes in a crystallization furnace in which melting furnace exhaust gas is circulated. Aggregate No. 1 obtained by holding the above, partially crystallizing it, and classifying it into a predetermined particle size.
- No. 9 are listed as examples of the present invention in the table. Next, aggregates No. 10 to No. 15 obtained with compositions and heat treatment conditions outside the numerically limited range of the present invention are described as reference examples. Furthermore, the results of a concrete strength test conducted in accordance with JIS standards using the aggregate produced as described above are shown in Table 1 in comparison with aggregates outside the numerical limits of the present invention and river sand. As is clear from the results, it was confirmed that the aggregate obtained by the present invention was superior in mechanical strength and chemical stability compared to the aggregate obtained by the reference example.
【表】【table】
【表】【table】
【表】【table】
【表】
なお、表−において圧壊強度破砕率は、
オートグラフ試験機による500Kg／cm2圧縮後の1.
2mm以下のスラグ重量／圧縮試験前のスラグ重量（1.2mm
〜2.5mm）×100
の式をもつて算出し、また、硫酸ナトリウム安定
性試験は、JIS Ａ−1132骨材の安定性試験による
５回繰返しの減量率（％）により示す。さらに、
表−において圧縮強度はJIS Ａ−1108、Ａ−
1132に準拠してテストピースサイズ150mm〓×
300mmHｎ＝３の平均値である。[Table] In addition, in the table, the crushing strength and crushing rate are 1.
Slag weight of 2mm or less/Slag weight before compression test (1.2mm
~2.5mm) x 100, and the sodium sulfate stability test is shown as the weight loss rate (%) of 5 repetitions of the JIS A-1132 aggregate stability test. moreover,
In the table, the compressive strength is JIS A-1108, A-
Test piece size 150 mm 〓× according to 1132
300 mmH This is the average value of n=3.
Claims (1)
同じ）、Al2O35〜15％、Fe2O35〜25％、CaO20〜
40％、MgO1〜５％、P2O53〜15％の範囲内でか
つ（CaO＋MgO）／SiO2の比を0.8〜1.2に組成調
整した廃棄物焼却灰を1350〜1500℃で溶融し、こ
の溶融物を急冷して熱衝撃破砕したのち前記溶融
工程で発生した排ガスを循環させた結晶化炉中に
おいて800℃以上1000℃未満の温度に20分以上保
持して結晶化することを特徴とする骨材の製造
法。1 Main composition is SiO 2 25-45% (weight%, same below), Al 2 O 3 5-15%, Fe 2 O 3 5-25%, CaO20-
40%, MgO 1-5%, P 2 O 5 3-15% and the composition of (CaO + MgO) / SiO 2 ratio adjusted to 0.8-1.2 is melted at 1350-1500°C, The molten material is rapidly cooled and subjected to thermal shock crushing, and then held at a temperature of 800°C or more and less than 1000°C for 20 minutes or more to crystallize it in a crystallization furnace in which exhaust gas generated in the melting process is circulated. A method for producing aggregate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58039833A JPS59164668A (en) | 1983-03-10 | 1983-03-10 | Manufacture of aggregate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58039833A JPS59164668A (en) | 1983-03-10 | 1983-03-10 | Manufacture of aggregate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59164668A JPS59164668A (en) | 1984-09-17 |
| JPH0118027B2 true JPH0118027B2 (en) | 1989-04-03 |
Family
ID=12563967
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58039833A Granted JPS59164668A (en) | 1983-03-10 | 1983-03-10 | Manufacture of aggregate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59164668A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0699167B2 (en) * | 1990-03-23 | 1994-12-07 | 川崎重工業株式会社 | Method for manufacturing waste molten slag |
| FR2712214B1 (en) * | 1993-11-10 | 1996-01-19 | Emc Services | Waste crystallization process. |
| JPH09328384A (en) * | 1996-06-07 | 1997-12-22 | N K K Plant Kensetsu Kk | Production of sludge melt-solidified form |
| JP3490221B2 (en) * | 1996-07-18 | 2004-01-26 | Ｊｆｅプラント＆サービス株式会社 | Method for producing molten solid from fly ash generated during sludge incineration |
| JP7095674B2 (en) * | 2019-11-29 | 2022-07-05 | Ｊｆｅスチール株式会社 | How to make concrete |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54152025A (en) * | 1978-05-22 | 1979-11-29 | Nichireki Chem Ind Co | Production of artificial aggregate by pressure graining sewage sludg burnt ash |
| JPS57140366A (en) * | 1981-02-17 | 1982-08-30 | Gifushi | Manufacture of aggregate from incineration ash |
-
1983
- 1983-03-10 JP JP58039833A patent/JPS59164668A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54152025A (en) * | 1978-05-22 | 1979-11-29 | Nichireki Chem Ind Co | Production of artificial aggregate by pressure graining sewage sludg burnt ash |
| JPS57140366A (en) * | 1981-02-17 | 1982-08-30 | Gifushi | Manufacture of aggregate from incineration ash |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59164668A (en) | 1984-09-17 |
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