JP6143009B2 - Pressurized steam aging method for steelmaking slag - Google Patents
Pressurized steam aging method for steelmaking slag Download PDFInfo
- Publication number
- JP6143009B2 JP6143009B2 JP2014073275A JP2014073275A JP6143009B2 JP 6143009 B2 JP6143009 B2 JP 6143009B2 JP 2014073275 A JP2014073275 A JP 2014073275A JP 2014073275 A JP2014073275 A JP 2014073275A JP 6143009 B2 JP6143009 B2 JP 6143009B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- aging
- slag
- water vapor
- steelmaking slag
- 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.)
- Active
Links
- 230000032683 aging Effects 0.000 title claims description 91
- 239000002893 slag Substances 0.000 title claims description 89
- 238000009628 steelmaking Methods 0.000 title claims description 37
- 238000000034 method Methods 0.000 title claims description 20
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 50
- 239000002245 particle Substances 0.000 claims description 38
- 229910000831 Steel Inorganic materials 0.000 claims description 17
- 239000010959 steel Substances 0.000 claims description 17
- 238000010521 absorption reaction Methods 0.000 claims description 9
- 229920006395 saturated elastomer Polymers 0.000 claims description 5
- 238000012545 processing Methods 0.000 claims description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 37
- 239000000395 magnesium oxide Substances 0.000 description 24
- 239000000463 material Substances 0.000 description 21
- 238000006703 hydration reaction Methods 0.000 description 16
- 238000007654 immersion Methods 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 7
- 230000006641 stabilisation Effects 0.000 description 5
- 238000011105 stabilization Methods 0.000 description 5
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 4
- 235000011941 Tilia x europaea Nutrition 0.000 description 4
- 239000004571 lime Substances 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 3
- 230000008961 swelling Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 238000007664 blowing Methods 0.000 description 2
- 238000005056 compaction Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 230000001914 calming effect Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003337 fertilizer Substances 0.000 description 1
- 230000002431 foraging effect Effects 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Landscapes
- Processing Of Solid Wastes (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Furnace Details (AREA)
Description
本発明は、製鋼スラグの膨張性を安定化させて、路盤材や水和固化体の骨材として再利用するための、製鋼スラグの加圧水蒸気エージング方法に関するものである。なお、本発明においては、上記「水蒸気」を単に「蒸気」とも略記する。 The present invention is to stabilize the expandable steel slag, for reuse as aggregate of roadbed and hydrated solidified body, to a pressurized water vapor aging process of steelmaking slag. In the present invention, the “water vapor” is also simply abbreviated as “steam”.
鉄鋼製造プロセスから発生する鉄鋼スラグには、高炉から副生する高炉スラグと、転炉や電気炉から副生する製鋼スラグがある。高炉スラグは、その製造方法によって水砕スラグと徐冷スラグに分けられる。水砕スラグは、溶融状態のスラグを高圧の水で瞬時に冷却、凝固させたもので粒径10mm以下の砂状でガラス質のスラグであり、主に高炉スラグ微粉末や高炉セメント用原料、軽量盛土材、コンクリート用細骨材として利用されている。また、徐冷スラグは、溶融状態のスラグをピットやヤードに放流し、長時間をかけて凝固させ、その後、破砕して約40mm以下に粒状化した結晶質のスラグであり、主に路盤材やコンクリート用粗骨材、セメントクリンカー原料として利用されている。 Steel slag generated from the steel manufacturing process includes blast furnace slag by-produced from a blast furnace and steelmaking slag by-produced from a converter or electric furnace. Blast furnace slag is divided into granulated slag and slow-cooled slag depending on the production method. Granulated slag is a sandy glassy slag with a particle size of 10 mm or less, which is obtained by instantaneously cooling and solidifying molten slag with high-pressure water. It is used as a lightweight embankment material and fine aggregate for concrete. Slowly cooled slag is a crystalline slag that discharges molten slag to pits and yards, solidifies it over a long period of time, and then crushes it to granulate to about 40 mm or less. It is used as a coarse aggregate for concrete and as a raw material for cement clinker.
一方、製鋼スラグは、ピットやヤードに放流して常温で凝固させ、その後、破砕しておよそ40mm以下に粒状化したものであり、主に骨材や路盤材、埋立材、サンドコンパクション材、肥料原料等として利用されている。しかし、この製鋼スラグには、精錬過程で添加された石灰源やマグネシア源が、未反応のままあるいは未溶融で遊離したまま多量に含まれている。そのため、製鋼スラグからの溶出水はpHが高く、また、遊離石灰等が水分を吸収して水和反応を起こすと、体積が2倍以上に膨張し、崩壊して微粉化したり、周囲の構造物を破壊したりするという問題がある。 Steelmaking slag, on the other hand, is discharged into pits and yards, solidified at room temperature, then crushed and granulated to approximately 40 mm or less, mainly aggregates, roadbed materials, landfill materials, sand compaction materials, fertilizers It is used as a raw material. However, this steelmaking slag contains a large amount of lime source and magnesia source added in the refining process, unreacted or unmelted and released. Therefore, the elution water from steelmaking slag has a high pH, and when free lime absorbs moisture and causes a hydration reaction, the volume expands more than twice, collapses and pulverizes, and the surrounding structure There is a problem of destroying things.
そこで、製鋼スラグを粒度分布規定や水浸膨張率が厳格な用途に適用する場合には、使用する前に水和反応を促進して膨張を沈静化(安定化)するエージング処理を施すことが必要となる。上記エージング処理の方法としては、遊離石灰等と水とを速やかに反応させる観点から、昇温すると同時に水分を供給することができる蒸気エージング法が一般的に用いられている。たとえば、特許文献1には、破砕した製鋼スラグを圧力容器に装入し、該圧力容器内に加圧水蒸気を供給して容器およびスラグを加熱することによって圧力容器内を昇温・昇圧し、次いで容器内を2〜10kg/cm2の圧力の飽和水蒸気雰囲気に1〜5hr保持した後、圧力容器内を大気圧まで減圧して製鋼スラグを排出するエージング方法が開示されている。また、特許文献2には、破砕した製鋼スラグを圧力容器に装入し、該圧力容器を密閉して内部に加圧水蒸気を供給することによって昇温・昇圧し、次いで該圧力容器の内部を2〜10kg/cm2の圧力の飽和水蒸気雰囲気に5hr以上保持した後、該圧力容器の内部を大気圧まで減圧して製鋼スラグを排出するエージング方法が開示されている。これらの技術は、いずれも、減圧の衝撃で粒子の崩壊を促進して、スラグ粒の内部まで安定化を進めようとするものである。 Therefore, when steelmaking slag is applied to applications where the particle size distribution regulation and water expansion coefficient are strict, it is necessary to accelerate the hydration reaction and use the aging treatment to stabilize (stable) expansion before use. Necessary. As a method of the aging treatment, a vapor aging method capable of supplying moisture at the same time as raising the temperature is generally used from the viewpoint of promptly reacting free lime and water with water. For example, in Patent Document 1, the crushed steelmaking slag is charged into a pressure vessel, and the pressure vessel is heated and pressurized by heating the vessel and slag by supplying pressurized steam into the pressure vessel, An aging method is disclosed in which the inside of a container is held in a saturated steam atmosphere at a pressure of 2 to 10 kg / cm 2 for 1 to 5 hours, and then the inside of the container is reduced to atmospheric pressure to discharge steelmaking slag. Further, in Patent Document 2, the crushed steelmaking slag is charged into a pressure vessel, the pressure vessel is sealed, and pressurized water vapor is supplied to the inside to raise the temperature and the pressure. An aging method is disclosed in which steelmaking slag is discharged by reducing the inside of the pressure vessel to atmospheric pressure after being held in a saturated steam atmosphere at a pressure of -10 kg / cm 2 for 5 hours or more. In any of these techniques, the collapse of particles is promoted by impact of reduced pressure, and stabilization is promoted to the inside of the slag grains.
しかしながら、製鋼スラグは、路盤材等の製品粒径に破砕した未エージングの状態では、粒子内にクラックが多く存在し、さらに、膨張源となる未消化のフリーライムやフリーMgOが粒内に多量かつ満遍なく存在するため、加圧蒸気で一定時間のエージング処理を施しても、膨張性を沈静化できないことがある。特に、JIS A 1110に規定された粗骨材(4.75mm以上)の吸水率が2.3mass%以上で、フリーCaOが4.0mass%以上、MgOが5.0mass%以上の場合には、上記の状況に陥る可能性が高い。というのは、加圧蒸気でエージング処理を施しても、エージング処理の終了間際に崩壊し、生成した新しい破面に露出した膨張源は、沈静化のための水和反応時間を十分に確保できないため、そこから膨張を起こすからである。 However, steelmaking slag has many cracks in the particles in an unaged state that has been crushed to a product particle size such as roadbed material, and a large amount of undigested free lime and free MgO as expansion sources. In addition, since it exists evenly, even if the aging treatment is performed for a certain time with pressurized steam, the expansibility may not be calmed down. In particular, when the water absorption of the coarse aggregate (4.75 mm or more) specified in JIS A 1110 is 2.3 mass% or more, free CaO is 4.0 mass% or more, and MgO is 5.0 mass% or more, The possibility of falling into the above situation is high. This is because, even if aging treatment is performed with pressurized steam, the expansion source exposed to the new fracture surface that has collapsed just before the end of the aging treatment cannot secure sufficient hydration reaction time for calming down. Therefore, it causes expansion from there.
本発明は、従来技術が抱える上記の問題点に鑑みてなされたものであり、その目的は、製鋼スラグの性状や組成によらず、加圧蒸気でエージング処理した製鋼スラグの膨張性を、破砕した製品粒度を保持したまま、安定して低減することができる製鋼スラグのエージング方法を提案することにある。 The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to crush the expansibility of steel slag that has been aged with pressurized steam, regardless of the properties and composition of the steel slag. An object of the present invention is to propose a method for aging steelmaking slag that can be stably reduced while maintaining the product particle size.
発明者らは、上記課題の解決に向けて鋭意検討を重ねた。その結果、製鋼スラグを高温・高圧の水蒸気でエージング処理した後、単に大気圧まで減圧するだけでなく、上記エージング処理後、所定の温度・圧力で所定時間保持することによって、エージング処理の終了間際に崩壊し、生成した新しい破面に露出した膨張源を沈静化することが有効であることを見出し、本発明を開発するに至った。 The inventors have intensively studied to solve the above problems. As a result, after aging the steelmaking slag with high-temperature and high-pressure steam, not only simply reducing the pressure to atmospheric pressure, but also holding the specified temperature and pressure for a predetermined time after the aging process, the aging process is about to end. It was found that it is effective to calm down the expansion source exposed to the newly generated fracture surface, and the present invention was developed.
すなわち、本発明は、40mm以下に破砕した製鋼スラグを圧力容器内に装入し、加圧水蒸気でエージングを施す方法において、飽和水蒸気圧で0.29〜0.98MPaに加圧して1〜5hr保持する一次エージングした後、水蒸気を放散して圧力容器内の水蒸気圧を0.14〜0.27MPaに減圧し、上記水蒸気圧に平衡する温度で0.5〜3hr保持する二次エージングした後、圧力容器内の圧力を大気圧まで減圧することを特徴とする製鋼スラグの加圧水蒸気エージング方法を提案する。 That is, the present invention provides a steel slag crushing into 40mm below were charged to a pressure vessel, a method of performing aging at pressurized water steam, pressurized in 0.29~0.98MPa with saturated aqueous vapor pressure 1 after primary aged holds ~5Hr, to dissipate water vapor under reduced pressure of water vapor pressure in the pressure vessel 0.14~0.27MPa, to 0.5~3hr maintained at a temperature in equilibrium with the water vapor pressure after secondary aging proposes pressurized water vapor aging process of steelmaking slag, which comprises reducing the pressure in the pressure vessel to atmospheric pressure.
本発明の上記製鋼スラグの加圧水蒸気エージング方法は、圧力容器内の水蒸気圧を0.14〜0.27MPaに減圧し、上記水蒸気圧に平衡する温度で0.5〜3hr保持した後、圧力容器内の水蒸気圧や温度を上げることなく、圧力容器内の圧力を大気圧まで減圧することを特徴とする。 Pressurized water vapor aging process of the steel slag of the invention, reducing the pressure of water vapor pressure in the pressure vessel 0.14~0.27MPa, and 0.5~3hr maintained at a temperature in equilibrium with the water vapor pressure after, without increasing the water vapor pressure and temperature in the pressure vessel, characterized by reducing the pressure in the pressure vessel to atmospheric pressure.
また、本発明の上記製鋼スラグの加圧水蒸気エージング方法は、JIS A 1110に規定された4.75mm以上の粒子の吸水率が2.3mass%以上の製鋼スラグを処理対象とすることを特徴とする。 Further, pressurized water vapor aging process of the steel slag of the invention, wherein the water absorption of defined 4.75mm or more particles in JIS A 1110 is processed to 2.3 mass% or more steel slag And
また、本発明の上記製鋼スラグの加圧水蒸気エージング方法は、f−CaOが4.0mass%以上および/またはMgOが5.0mass%以上の製鋼スラグを処理対象とすることを特徴とする。 Further, pressurized water vapor aging process of the steel slag of the invention, f-CaO is 4.0 mass% or more and / or MgO is equal to or to be processed for 5.0 mass% or more steel slag.
本発明の加圧蒸気エージング方法によれば、製鋼スラグの膨張性を、破砕した製品粒度を保持したまま低減することができるので、製鋼スラグの用途拡大に大きく寄与することができる。 According to the pressurized steam aging method of the present invention, the expansibility of steelmaking slag can be reduced while maintaining the crushed product particle size, which can greatly contribute to the expansion of the use of steelmaking slag.
まず、本発明の技術思想について説明する。
密閉した圧力容器内での加圧蒸気によるエージング処理では、容器内に装入したスラグ粒子の内部まで均一に蒸気が進入し、水分を供給する。さらに、加圧蒸気下では、雰囲気温度を、大気圧で平衡する100℃より高い温度とすることができる。そのため、スラグ粒子の表面や、粒子内に延びた亀裂(クラック)の破面に存在するフリーCaO(以降、「f−CaO」とも記す)やフリーMgO(以降、「f−MgO」とも記す)の水和反応が促進される。
First, the technical idea of the present invention will be described.
In an aging process using pressurized steam in a sealed pressure vessel, the steam uniformly enters the inside of the slag particles charged in the vessel and supplies moisture. Furthermore, under pressurized steam, the ambient temperature can be set to a temperature higher than 100 ° C., which is balanced at atmospheric pressure. Therefore, free CaO (hereinafter also referred to as “f-CaO”) and free MgO (hereinafter also referred to as “f-MgO”) existing on the surface of the slag particles and the fracture surface of the cracks (cracks) extending in the particles. The hydration reaction is promoted.
この水和反応は、体積膨張を伴うため、f−CaOやf−MgO等の膨張源が、スラグ粒の内部まで食い込んでいたり、クラック内部に存在していたりする場合には、スラグ粒子そのものが崩壊を起こして細粒化する。そのため、加圧蒸気下でのエージング処理の終了間際に崩壊したスラグ粒子に関しては、崩壊で露出した新しい破面や発生した細粒分には、エージング処理終了後も、未反応の膨張源が残ってしまう。 Since this hydration reaction involves volume expansion, if an expansion source such as f-CaO or f-MgO bites into the interior of the slag grains or exists inside the cracks, the slag particles themselves Causes collapse and refines. Therefore, for slag particles that collapsed just before the end of the aging treatment under pressurized steam, unreacted expansion sources remain even after the aging treatment is completed on the new fracture surface exposed by the collapse and the generated fine particles. End up.
特に、吸水率が高いスラグ粒子は、粒の表面から内部に延びるクラックや気孔が多いため、加圧蒸気によるエージング処理では、スラグ粒子内部の膨張源も表面から侵入してくる水分と水和反応を起こして粒子の膨張・崩壊を起こす。そして、破面に新たな膨張源が現れるとともに、粗大な膨張源は、エージング未了部分を含んだ微細粒子となる。 In particular, slag particles with a high water absorption rate have many cracks and pores extending from the surface of the grain to the inside, so in the aging treatment with pressurized steam, the slag particle's internal expansion source also penetrates from the surface with water hydration reaction Causes the particles to expand and collapse. And while a new expansion | swelling source appears on a fracture surface, a coarse expansion | swelling source turns into a fine particle containing the aging incomplete part.
つまり、先述した特許文献3や4に開示された技術のように、スラグ粒子が膨張・崩壊した後、時間を置かずに高圧に保たれていた蒸気圧を減圧してエージング処理を終了してしまうと、未エージングのf−CaOやf−MgOが崩壊した破面や細粒分の表面に露出したままとなる。このような状態のスラグ粒子は、蒸気エージングを実施したにも拘わらず、まだ膨張性を残しているため、これを、JIS A 5015附属書2に定められた80℃水浸膨張試験で評価した場合には、浸漬した早い時期から水和反応が進んで高い膨張性を示すことになり、路盤材や人工骨材としての基準をクリアできなくなる。 That is, like the techniques disclosed in Patent Documents 3 and 4 described above, after the slag particles expand and collapse, the aging process is terminated by reducing the vapor pressure maintained at a high pressure without taking time. In other words, the unaged f-CaO and f-MgO remain exposed on the fracture surface and the surface of fine particles. Although the slag particles in such a state still have expansibility despite the steam aging, this was evaluated by the 80 ° C. water immersion expansion test defined in JIS A 5015 Annex 2. In such a case, the hydration reaction proceeds from the early stage of immersion and exhibits high expansibility, and the standards for roadbed materials and artificial bone materials cannot be cleared.
そして、上記膨張性を低減するために、さらに高温、高圧蒸気下でエージングすると、スラグ粒子内部の膨張源を徹底して安定化することとなり、粒子をさらに崩壊させるため、エージング後の製品は粒径が低下し、例えば、JIS A 5015「道路用鉄鋼スラグ」に規定されたHMS−25の粒度基準(4.75mm未満が35〜60mass%)を満たさなくなる。 And in order to reduce the expansibility, when aging under higher temperature and high pressure steam, the expansion source inside the slag particles will be thoroughly stabilized, and the particles after aging will be further broken down. The diameter decreases, and for example, the particle size standard of HMS-25 defined in JIS A 5015 “Steel Slag for Roads” (less than 4.75 mm is 35 to 60 mass%) is not satisfied.
ところで、100℃の常圧蒸気でエージングしたスラグ粒子(常圧蒸気エージング材)と、加圧蒸気でエージングしたスラグ粒子(加圧蒸気エージング材)の80℃水浸膨張曲線を比較すると、常圧蒸気エージング材は、低くかつほぼ一定の速度で膨張を起こすのに対して、加圧蒸気エージング材は、浸漬開始直後の膨張が急速で、その後、膨張速度が鈍って一定となり、常圧蒸気エージング材の水浸膨張速度よりも低くなる。 By the way, when comparing the 80 ° C. water immersion expansion curves of slag particles aged with normal pressure steam at 100 ° C. (normal pressure steam aging material) and slag particles aged with pressurized steam (pressure steam aging material), normal pressure Steam aging material expands at a low and almost constant rate, whereas pressurized steam aging material expands rapidly immediately after the start of immersion, and then the expansion rate becomes slow and constant. It becomes lower than the water immersion expansion rate of the material.
加圧蒸気エージング材の上記浸漬直後の急速な膨張は、水和反応速度が速いf−CaOによるものであり、一方、加圧蒸気エージング材の浸漬開始直後以降や常圧蒸気エージング材において一定の速度で起こる緩慢な膨張は、f−MgOの未反応分が緩慢に反応するためであると考えられている。したがって、膨張性を低減するためには、反応速度が小さいf−MgOの水和反応を抑制してスラグ粒子の膨張・崩壊を抑制すると同時に、既に露出した反応速度が大きいf−CaOを優先的に水和反応させることが有効であると考えられる。 The rapid expansion immediately after the immersion of the pressurized steam aging material is due to f-CaO, which has a fast hydration reaction rate. On the other hand, after the start of the immersion of the pressurized steam aging material, it is constant in the atmospheric steam aging material. It is believed that the slow expansion that occurs at a rate is due to the slow reaction of the unreacted portion of f-MgO. Therefore, in order to reduce the expansibility, the hydration reaction of f-MgO having a low reaction rate is suppressed to suppress the expansion / collapse of the slag particles, and at the same time, the already exposed f-CaO having a high reaction rate is preferentially used. It is considered effective to cause hydration reaction.
そこで、本発明は、前述したような状態に陥るのを防ぐために、従来の高温加圧蒸気によるエージング(以降、「一次エージング」ともいう)の最終段階で圧力容器内の蒸気圧を、常圧以上の適度な圧力まで下げ、その圧力に平衡する温度で一定時間保持するエージング(以降「二次エージング」ともいう)を施し、その後、再昇温することなく、常温に向けて冷却することとした。 Therefore, in order to prevent the present invention from falling into the state described above, the vapor pressure in the pressure vessel is changed to normal pressure at the final stage of aging with conventional high-temperature pressurized steam (hereinafter also referred to as “primary aging”). Applying aging (hereinafter also referred to as “secondary aging”) to lower the above-mentioned moderate pressure and holding it at a temperature that equilibrates to that pressure for a certain period of time, and then cooling to room temperature without reheating. did.
というのは、高温高圧蒸気下では、スラグ粒内の亀裂や気孔に進入した蒸気が、スラグ粒子内部に存在する膨張源の速やかな水和反応を促進して、粒子を崩壊させ、未反応の膨張源を露出させる。しかし、本発明のように、高温高圧での一次エージング後に、引き続き適度な蒸気圧(温度)の条件下で二次エージングすると、スラグ粒子が崩壊を引き起こすような激しい反応は抑制される。特に、反応速度が遅いf−MgOによる膨張・崩壊は大きく減少する。一方、減圧(冷却)前に露出済みの膨張源の水和反応は引き続き継続して起こる。特に、f−CaOの水和反応は、f−MgOに比較して速やかに進行する。そのため、新たな膨張源の露出が抑制されて、既に露出した膨張源のみを安定化することができるからである。 This is because under high-temperature and high-pressure steam, steam that has entered cracks or pores in the slag grains promotes a rapid hydration reaction of the expansion source existing inside the slag particles, causing the particles to collapse and unreacted. Expose the source of expansion. However, as in the present invention, if secondary aging is subsequently performed under conditions of moderate vapor pressure (temperature) after primary aging at high temperature and high pressure, vigorous reactions that cause the slag particles to collapse are suppressed. In particular, the expansion / collapse due to the slow reaction rate of f-MgO is greatly reduced. On the other hand, the hydration reaction of the expansion source that has been exposed before decompression (cooling) continues to occur. In particular, the hydration reaction of f-CaO proceeds more rapidly than f-MgO. Therefore, exposure of a new expansion source is suppressed, and only the already exposed expansion source can be stabilized.
次に、本発明の高圧蒸気エージング方法について説明する。
まず、高温高圧蒸気による一次エージングは、飽和蒸気圧で0.29〜0.98MPaに加圧し、1〜5hr保持する必要がある。蒸気圧を0.29MPa以上とすることにより、圧力容器内の温度が十分高温になり(圧力容器内は133℃以上)、膨張源の水和反応が促進されるためである。好ましくは0.5MPa以上(圧力容器内は152℃以上)である。一方、0.98MPa以下とするのは、通常、使用されているオートクレーブは、0.98MPaを設備仕様上の上限とするものが一般的であり、これ以上の高圧とすることは設備コストが増大するからである。また、上記温度に保持する時間を1〜5hrとするのは、1hr未満では、高温高圧蒸気による一次エージングの効果が十分に得られず、一方、5hrを超えると、スラグ粒子の崩壊が進んで細粒化したり、加圧蒸気エージング法の特長である高生産性が失われたりするからである。
Next, the high-pressure steam aging method of the present invention will be described.
First, primary aging with high-temperature and high-pressure steam needs to be pressurized to 0.29 to 0.98 MPa with a saturated vapor pressure and held for 1 to 5 hours. This is because by setting the vapor pressure to 0.29 MPa or more, the temperature in the pressure vessel becomes sufficiently high (133 ° C. or more in the pressure vessel), and the hydration reaction of the expansion source is promoted. Preferably, it is 0.5 MPa or more (inside the pressure vessel is 152 ° C. or more). On the other hand, 0.98 MPa or less is generally used for autoclaves that have an upper limit of 0.98 MPa in terms of equipment specifications, and a higher pressure than this increases equipment costs. Because it does. In addition, when the temperature is maintained at 1 to 5 hours, the effect of primary aging by the high-temperature and high-pressure steam is not sufficiently obtained when the time is less than 1 hour, while when the time exceeds 5 hours, the slag particles are further collapsed. This is because the fine productivity is lost or the high productivity characteristic of the pressurized steam aging method is lost.
次に、上記一次エージングに続く、減圧(降温)後の二次エージングの処理の蒸気圧は、0.14〜0.27MPaの範囲とする。これにより、圧力容器内の温度は、110〜130℃となる。蒸気圧で0.27MPa超えとした場合、温度が高すぎて、f−MgOによる膨張・崩壊を抑制できず、一方、0.14MPa未満では、既に露出した膨張源の水和反応速度を促進する効果が小さく、安定化に要する時間が3hrを超えて長時間となり、加圧蒸気エージング法の特長である高生産性が失われるからである。また、上記蒸気圧で0.5hr以上保持するのは、0.5hr未満では、スラグ粒子表面に露出したf−CaOの反応を促進する効果が十分ではないからである。 Next, the vapor pressure of the secondary aging treatment after the pressure reduction (temperature decrease) following the primary aging is set to a range of 0.14 to 0.27 MPa. Thereby, the temperature in a pressure vessel will be 110-130 degreeC. When the vapor pressure exceeds 0.27 MPa, the temperature is too high to suppress the expansion / collapse due to f-MgO. On the other hand, when it is less than 0.14 MPa, the hydration reaction rate of the already exposed expansion source is promoted. This is because the effect is small, the time required for stabilization exceeds 3 hours, and the high productivity characteristic of the pressurized steam aging method is lost. Further, the reason why the vapor pressure is maintained for 0.5 hr or more is that if it is less than 0.5 hr, the effect of promoting the reaction of f-CaO exposed on the surface of the slag particles is not sufficient.
なお、上記一次エージングから二次エージングへの遷移は、一次エージングが終了した後、減圧弁(蒸気弁)を開き、蒸気を放散して圧力容器内の蒸気圧を0.14〜0.27MPa間の二次エージングの予定圧力に減圧した後、減圧弁を閉じる。その後、圧力容器や装入したスラグ層の余熱によって、スラグ層内の水分が蒸気化し、容器内の圧力が上昇し、二次エージングの予定圧力を超えたら、再度、減圧弁を開いて二次エージングの予定圧力以下に減圧し、減圧弁を閉じる。この操作を繰り返して行い、減圧弁を開いているときの容器内圧力が二次エージングの予定圧力を安定して示すようになった時点を遷移完了、すなわち、二次エージング開始時と判断する。なお、一次エージングから二次エージングへの遷移時間は、通常、0.5〜1hrである。 The transition from primary aging to secondary aging is as follows. After primary aging is completed, the pressure reducing valve (steam valve) is opened to dissipate the steam so that the steam pressure in the pressure vessel is between 0.14 and 0.27 MPa. After reducing the pressure to the expected secondary aging pressure, the pressure reducing valve is closed. After that, if the residual heat of the pressure vessel and the slag layer is charged, the moisture in the slag layer evaporates and the pressure in the vessel rises, and when the pressure exceeds the planned secondary aging pressure, the pressure reducing valve is opened again to open the secondary Reduce the pressure below the expected aging pressure and close the pressure reducing valve. This operation is repeated, and it is determined that the transition is completed, that is, the secondary aging is started, when the pressure in the container when the pressure reducing valve is opened stably shows the scheduled secondary aging pressure. The transition time from primary aging to secondary aging is usually 0.5 to 1 hr.
次に、本発明の加圧蒸気エージング法を適用する製鋼スラグについて説明する。
まず、本発明を適用する製鋼スラグは、40mm以下に破砕したものであることが必要である。その理由は、路盤材や水和固化体の骨材等に使用する場合には、40mm以下の破砕したものを用いるのが一般的であるからである。
Next, steelmaking slag to which the pressurized steam aging method of the present invention is applied will be described.
First, the steelmaking slag to which the present invention is applied needs to be crushed to 40 mm or less. The reason is that, when used for roadbed materials, aggregates of hydrated solid bodies, etc., it is common to use crushed ones of 40 mm or less.
また、本発明を適用する製鋼スラグは、例えば、40mm以下の粒度に破砕した時点で、粗粒に多くのクラックを内在しているもの、具体的には、JIS A 1110における粗骨材(4.75mm以上)の吸水率が2.3mass%以上であるものが好ましい。その理由は、先述したように、多くのクラックを有するスラグ粒子は、粒子内部に吸収される水量が多く、膨張・崩壊を起こし易いためである。 In addition, the steelmaking slag to which the present invention is applied is, for example, a material in which many cracks are inherent in coarse particles at the time of crushing to a particle size of 40 mm or less, specifically, coarse aggregate (4 in JIS A 1110 (.75 mm or more) having a water absorption rate of 2.3 mass% or more is preferable. The reason is that, as described above, the slag particles having many cracks have a large amount of water absorbed inside the particles and are likely to expand and collapse.
また、上記製鋼スラグは、f−CaOが4.0mass%以上および/またはMgOが5.0mass%以上のものであることが好ましい。というのは、製鋼スラグにおける主な膨張源は、f−CaOとf−MgOであるが、f−CaOを4.0mass%以上含有すると、膨張が激しく、安定化する必要性が高くなるからである。 The steelmaking slag is preferably one having f-CaO of 4.0 mass% or more and / or MgO of 5.0 mass% or more. This is because the main expansion sources in steelmaking slag are f-CaO and f-MgO, but when f-CaO is contained in an amount of 4.0 mass% or more, the expansion is severe and the necessity for stabilization increases. is there.
一方、f−MgOは、定量法が確立されていないが、定性的にはMgOの含有率の高いほどf−MgOも高く、膨張性も大きいと考えられる。精錬時に添加したMgOは、添加量が多いと溶解せずにスラグ中に残り、膨張源となる。発明者らの従来の知見では、製鋼スラグ中のMgOが5.0mass%を超えると、MgOの未溶融物が見られるようになる。そこで、MgOの含有量が5.0mass%以上のものを本発明の処理対象とするのが好ましい。 On the other hand, a quantitative method for f-MgO has not been established, but qualitatively, the higher the content of MgO, the higher the f-MgO and the higher the expansibility. MgO added at the time of refining will not melt | dissolve but will remain in a slag, and will become an expansion | swelling source if there is much addition amount. According to the inventors' conventional knowledge, when MgO in the steelmaking slag exceeds 5.0 mass%, an unmelted MgO can be seen. Therefore, it is preferable that the MgO content is 5.0 mass% or more as a processing target of the present invention.
上記製鋼スラグに、本発明の高圧蒸気エージング方法を適用した場合には、製鋼スラグの膨張性、水浸膨張試験開始直後の膨張性が抑制されて、膨張性基準を安定的にクリアすることが可能となる。 When the high-pressure steam aging method of the present invention is applied to the steelmaking slag, the expansibility of the steelmaking slag and the expansibility immediately after the start of the water immersion expansion test are suppressed, and the expansibility criteria can be stably cleared. It becomes possible.
30mm以下に破砕した製鋼スラグを、実験用のオートクレーブを用いて、表1に示した各種条件で加圧蒸気エージングを施す実験を行った。
上記製鋼スラグは、JIS A 1110で測定した粗骨材(4.75mm以上)の吸水率が2.54mass%、f−CaOが4.5mass%、MgO含有量が5.4mass%で、蒸気エージング前の水浸膨張率が3.5%のものである。なお、実験の一部には、吸水率が2.02mass%、f−CaOが4.6mass%、MgO含有量が5.3mass%で、蒸気エージング前の水浸膨張率が3.6%の製鋼スラグも用いた。
また、実験に用いたオートクレーブには、蒸気吹込みにより昇温・昇圧する横置き式のもので、0.98MPaを設備仕様上の上限とするものである。
The steelmaking slag crushed to 30 mm or less was subjected to pressurized steam aging under various conditions shown in Table 1 using an experimental autoclave.
The steelmaking slag has a water absorption of 2.54 mass%, f-CaO is 4.5 mass%, MgO content is 5.4 mass%, and steam aging is measured according to JIS A 1110. The previous water immersion expansion rate is 3.5%. In some of the experiments, the water absorption is 2.02 mass%, f-CaO is 4.6 mass%, the MgO content is 5.3 mass%, and the water immersion expansion rate before steam aging is 3.6%. Steelmaking slag was also used.
The autoclave used in the experiment is a horizontal type that raises and raises the pressure by blowing steam, and the upper limit is 0.98 MPa in equipment specifications.
上記製鋼スラグの加圧蒸気エージング処理は、1回の処理当たり30kgの製鋼スラグを複数の白金金網に入れて、オートクレーブ内の棚に段置きし、蒸気を吹き込み、表1に示した条件(温度(蒸気圧)×時間)で一次エージングした後、減圧弁から圧力容器内部の蒸気を放散して表1に示した二次エージングの予定圧力(温度)以下になるまで減圧し、減圧弁を閉じた。その後、オートクレーブの余熱でスラグ層内の水分が蒸気化し、圧力容器内の蒸気圧が二次エージングの目標圧力を超えた場合には、再度、減圧弁を開いて圧力容器内の圧力を上記目標圧力以下まで減圧してから減圧弁を閉める操作を繰り返して行い、圧力容器内の圧力(温度)が二次エージングの予定圧力(温度)に安定した時点で二次エージングを開始し、その後、容器内の圧力を大気圧まで減圧した。
なお、比較例として、第2段階のエージング処理を施さない実験も行った。
The pressurized steam aging treatment of the steelmaking slag is performed by placing 30 kg of steelmaking slag per treatment into a plurality of platinum wire meshes, placing it on a shelf in an autoclave, blowing steam, and the conditions (temperatures shown in Table 1) (Vapour pressure) x time) after primary aging, the vapor inside the pressure vessel is released from the pressure reducing valve, the pressure is reduced to below the planned secondary aging pressure (temperature) shown in Table 1, and the pressure reducing valve is closed. It was. After that, when the moisture in the slag layer evaporates due to the residual heat of the autoclave and the vapor pressure in the pressure vessel exceeds the secondary aging target pressure, the pressure reducing valve is opened again to adjust the pressure in the pressure vessel to the above target Repeat the operation of closing the pressure reducing valve after reducing the pressure to below the pressure, and start secondary aging when the pressure (temperature) in the pressure vessel stabilizes at the expected secondary aging pressure (temperature). The internal pressure was reduced to atmospheric pressure.
As a comparative example, an experiment in which the second-stage aging treatment was not performed was also performed.
次いで、上記加圧蒸気エージング処理した製鋼スラグについて、粒度をJIS A 1102,1103に従って測定し、JIS A 5015「道路用鉄鋼スラグ」に規定されたHMS−25の粒度基準(4.75mm未満が35〜60mass%)を満たしていることを確認した後、その粒度のままで、JIS A 5015附属書2に定められた水浸膨張試験に供した。
なお、膨張性の評価基準は、JIS A 5015「道路用鉄鋼スラグ」では、水浸膨張率を1.5%以下と規定しているが、実操業では製品のバラつきがあることから、より厳しい0.5%以下を目標基準として設定した。
Next, for the steelmaking slag subjected to the above-mentioned pressurized steam aging treatment, the particle size was measured according to JIS A 1102, 1103, and the particle size standard of HMS-25 defined in JIS A 5015 “steel slag for roads” (less than 4.75 mm is 35 (60 mass%) was satisfied, and the particle size was subjected to a water immersion expansion test defined in Appendix 2 of JIS A 5015.
In addition, JIS A 5015 “Steel slag for roads” stipulates that the expansion rate of water immersion is 1.5% or less, but the actual operation is more severe due to product variations. 0.5% or less was set as a target standard.
上記水浸膨張率の測定結果を表1に併記した。
比較例1は、加圧蒸気で0.59MPa(158℃)×8hr保持する一次エージングのみの例であり、水浸膨張率は、未エージング材(3.5%)より大幅に低減しているものの、目標基準(0.5%)を上回っている。
また、比較例2は、比較例1に対して一次エージングの処理圧力を0.26MPa(15℃)上げて水和反応速度を高め、その分、時間を5hr短縮して、0.85MPa(173℃)×3hr保持した例であり、比較例1と同等レベルまで水浸膨張率が低下しているが、まだ目標基準(0.5%以下)を上回っている。
また、比較例3は、比較例2に対して一次エージングの保持時間を3hr延長した例であるが、膨張率の低下は小さく、まだ目標基準(0.5%以下)を上回っている。
The measurement results of the water expansion coefficient are also shown in Table 1.
Comparative Example 1 is an example of only primary aging that is maintained at 0.59 MPa (158 ° C.) × 8 hr with pressurized steam, and the water immersion expansion rate is significantly reduced as compared with the non-aging material (3.5%). However, it exceeds the target standard (0.5%).
In Comparative Example 2, the aging reaction pressure was increased by 0.26 MPa (15 ° C.) relative to Comparative Example 1 to increase the hydration reaction rate, and the time was reduced by 5 hours, so that 0.85 MPa (173 (° C.) × 3 hours, and the water immersion expansion rate has decreased to a level equivalent to that of Comparative Example 1, but still exceeds the target standard (0.5% or less).
Comparative Example 3 is an example in which the retention time of primary aging is extended by 3 hours compared to Comparative Example 2, but the decrease in the expansion rate is small and still exceeds the target standard (0.5% or less).
一方、発明例1は、一次エージングを比較例2と同じ条件(0.85MPa(173℃)×3hr)で処理した後、(0.14MPa(110℃)×2.0hr)で二次エージングを施した例であり、総処理時間が比較例3と同じであるにもかかわらず、目標基準(0.5%以下)を達成している。
また、発明例2および3は、発明例1における二次エージングの処理温度を上げ、保持時間を変化させた例であり、いずれも目標基準(0.5%以下)を達成している。特に、保持時間が長い方が、安定化効果に優れている。
On the other hand, in Invention Example 1, primary aging was treated under the same conditions as in Comparative Example 2 (0.85 MPa (173 ° C.) × 3 hr), and then secondary aging was performed at (0.14 MPa (110 ° C.) × 2.0 hr). In this example, although the total processing time is the same as that of Comparative Example 3, the target standard (0.5% or less) is achieved.
Inventive Examples 2 and 3 are examples in which the secondary aging treatment temperature in Inventive Example 1 was increased and the holding time was changed, and both achieved the target standard (0.5% or less). In particular, the longer the holding time, the better the stabilizing effect.
なお、比較例4は、エージング前における吸水率が2.02mass%と低い製鋼スラグに、エージング処理を施した例であるが、一次エージングのみで目標基準(0.5%以下)に到達している。
また、発明例4は、比較例4と同じ吸水率の低い製鋼スラグに、本発明の処理を施した例であるが、安定化の改善代は、発明例3より若干良好となる程度でしかない。
これは、上記例に用いた製鋼スラグは、そもそも緻密でクラックが少なく、膨張・崩壊性の低いものであるため、一次エージングの終了間際に崩壊する粒子が少なく、一次エージングのみで安定化が十分に進むからである。
In addition, although the comparative example 4 is an example which performed the aging process to the steelmaking slag whose water absorption before aging is as low as 2.02 mass%, it reached the target standard (0.5% or less) only by primary aging. Yes.
Inventive Example 4 is an example in which the steelmaking slag having the same low water absorption rate as Comparative Example 4 is subjected to the treatment of the present invention. However, the improvement cost for stabilization is only slightly better than Inventive Example 3. Absent.
This is because the steelmaking slag used in the above example is dense, has few cracks, and has a low expansion / disintegration property.Therefore, there are few particles that collapse just before the end of primary aging, and stabilization is sufficient with only primary aging. Because it goes to.
本発明の技術は、同様の粒度でスラグを用いるサンドコンパクション材やケーソンの中込め材などの土木材料にも適用することができる。 The technology of the present invention can also be applied to civil engineering materials such as sand compaction materials using slag with the same particle size and caisson filling materials.
Claims (4)
飽和水蒸気圧で0.29〜0.98MPaに加圧して1〜5hr保持する一次エージングした後、水蒸気を放散して圧力容器内の水蒸気圧を0.14〜0.27MPaに減圧し、上記水蒸気圧に平衡する温度で0.5〜3hr保持する二次エージングした後、圧力容器内の圧力を大気圧まで減圧することを特徴とする製鋼スラグの加圧水蒸気エージング方法。 The crushed steel slag to 40mm below were charged to a pressure vessel, a method of performing aging at pressurized water steam,
After primary aged to 1~5hr hold pressurized to 0.29~0.98MPa with saturated aqueous vapor pressure, reduced to 0.14~0.27MPa water vapor pressure in the pressure vessel to dissipate water vapor after secondary aging to 0.5~3hr maintained at a temperature in equilibrium with the water vapor pressure, pressurized water vapor aging process of steelmaking slag, which comprises reducing the pressure in the pressure vessel to atmospheric pressure.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014073275A JP6143009B2 (en) | 2014-03-31 | 2014-03-31 | Pressurized steam aging method for steelmaking slag |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014073275A JP6143009B2 (en) | 2014-03-31 | 2014-03-31 | Pressurized steam aging method for steelmaking slag |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2015193508A JP2015193508A (en) | 2015-11-05 |
JP6143009B2 true JP6143009B2 (en) | 2017-06-07 |
Family
ID=54432928
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2014073275A Active JP6143009B2 (en) | 2014-03-31 | 2014-03-31 | Pressurized steam aging method for steelmaking slag |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP6143009B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7137870B2 (en) | 2018-12-04 | 2022-09-15 | 学校法人近畿大学 | Fish behavior control method |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6595964B2 (en) * | 2016-10-17 | 2019-10-23 | Jfeミネラル株式会社 | Repair method for roadbed |
JP6720937B2 (en) * | 2017-08-03 | 2020-07-08 | Jfeスチール株式会社 | Steelmaking slag roadbed material manufacturing method |
JP7253981B2 (en) * | 2019-05-31 | 2023-04-07 | 日本製鉄株式会社 | Method for producing iron and steel slag hydrated solid |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5227871Y2 (en) * | 1973-03-19 | 1977-06-24 | ||
JPH04254187A (en) * | 1991-02-01 | 1992-09-09 | Sumitomo Metal Ind Ltd | Method of continuously aging slug in steel making |
JPH05238786A (en) * | 1992-02-26 | 1993-09-17 | Sumitomo Metal Ind Ltd | Method for aging steel making slag and device therefor |
JP2865511B2 (en) * | 1993-02-24 | 1999-03-08 | 新日本製鐵株式会社 | Method and apparatus for promoting hydration and crushing of steelmaking slag |
JP2865514B2 (en) * | 1993-03-31 | 1999-03-08 | 新日本製鐵株式会社 | Water-cooled crushing equipment for high-temperature steelmaking slag |
JPH07237946A (en) * | 1994-02-24 | 1995-09-12 | Kawasaki Steel Corp | Method for reducing powdering of slag for steel manufacture |
JPH08119692A (en) * | 1994-10-17 | 1996-05-14 | Kawasaki Steel Corp | Aging of steelmaking slag |
JP2667800B2 (en) * | 1995-10-26 | 1997-10-27 | 住友金属工業株式会社 | Aging method and apparatus for steelmaking slag |
JP2667799B2 (en) * | 1995-10-26 | 1997-10-27 | 住友金属工業株式会社 | Aging method for steelmaking slag |
JP2873178B2 (en) * | 1994-12-12 | 1999-03-24 | 住友金属工業株式会社 | Aging method and apparatus for steelmaking slag |
JP3230416B2 (en) * | 1995-07-14 | 2001-11-19 | 日本鋼管株式会社 | Steam aging treatment method for steelmaking slag |
JP4765535B2 (en) * | 2005-10-13 | 2011-09-07 | 住友金属工業株式会社 | Aging method of steelmaking slag |
JP2011105519A (en) * | 2009-11-12 | 2011-06-02 | Sanyo Special Steel Co Ltd | Rapid aging method for steel slag |
JP5384446B2 (en) * | 2010-08-20 | 2014-01-08 | 新日鐵住金株式会社 | Aging method of steelmaking slag |
-
2014
- 2014-03-31 JP JP2014073275A patent/JP6143009B2/en active Active
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7137870B2 (en) | 2018-12-04 | 2022-09-15 | 学校法人近畿大学 | Fish behavior control method |
Also Published As
Publication number | Publication date |
---|---|
JP2015193508A (en) | 2015-11-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6143009B2 (en) | Pressurized steam aging method for steelmaking slag | |
JP3828897B2 (en) | Method for stabilizing steelmaking slag and stabilized steelmaking slag | |
JP2001049310A (en) | Method for agglomerating steelmaking slag | |
JP2017007880A (en) | Ageing method of steelmaking slag | |
JP5126524B2 (en) | Manufacturing method for civil engineering materials using steel slag | |
JP2007031220A (en) | Method of granulating slag and granulated slag | |
JP6143008B2 (en) | Pressurized steam aging method for steelmaking slag | |
JP3828895B2 (en) | Method for stabilizing steelmaking slag and stabilized steelmaking slag | |
JP6460169B2 (en) | Manufacturing method of steelmaking slag roadbed material | |
JP2019026538A (en) | Method for producing steel-making slag roadbed material | |
JP6766831B2 (en) | Manufacturing method of steelmaking slag roadbed material | |
US20230183131A1 (en) | Process for stabilizing steel slag | |
KR20060014708A (en) | Composition of lightweight aggregate and menufacturing method of lightweight aggregate thereby | |
JP4765535B2 (en) | Aging method of steelmaking slag | |
JP4362494B2 (en) | Granulation method of powdered slag | |
JP2021042093A (en) | Recycled raw material for autoclaved lightweight aerated concrete and manufacturing method of autoclaved lightweight aerated concrete using thereof | |
JP6292257B2 (en) | Hydrated solidified product using desulfurized slag | |
JP2013087011A (en) | Steel slag hydration hardened body, and method for manufacturing the same | |
JP5668640B2 (en) | Steel slag roadbed material and method of manufacturing steel slag roadbed material | |
JP6766832B2 (en) | Manufacturing method of steelmaking slag roadbed material | |
JP6195460B2 (en) | Method for producing anti-bleeding agent for concrete and method for producing cement composition containing the anti-bleeding agent for concrete | |
JP5381383B2 (en) | Method for producing non-inflatable roadbed material | |
JP2000334418A (en) | Method for solidifying steel making slag | |
JP6182929B2 (en) | Manufacturing method of steelmaking slag roadbed material | |
JP3434019B2 (en) | How to Recycle Cement Flake Board Waste |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20151027 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20160907 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20160914 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20161107 |
|
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: 20170412 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20170425 |
|
R150 | Certificate of patent or registration of utility model |
Ref document number: 6143009 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
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 |