JP6766831B2 - Manufacturing method of steelmaking slag roadbed material - Google Patents
Manufacturing method of steelmaking slag roadbed material Download PDFInfo
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この発明は、製鋼スラグを蒸気エージングして製造される製鋼スラグ路盤材の製造方法に関する。 The present invention relates to a method for producing a steelmaking slag roadbed material produced by steam aging steelmaking slag.
製鋼スラグは、精錬で添加される石灰源やマグネシア源の一部が未溶融或いは他の成分と化合物を形成しないで遊離したまま残留している。このような遊離ＣａＯや遊離ＭｇＯが水分と水和反応すると、体積が２倍以上に膨張して周囲の構造物を破壊するため、製鋼スラグを石材や道路路盤材として利用するには、使用前の段階で水和反応を促進して沈静化しておく必要がある。 In steelmaking slag, a part of the lime source or magnesia source added by refining remains unmelted or remains free without forming a compound with other components. When such free CaO and free MgO undergo a hydration reaction with water, the volume expands more than twice and the surrounding structures are destroyed. Therefore, before using the steelmaking slag as a stone material or a roadbed material, before use. It is necessary to promote the hydration reaction and keep it calm at the stage of.
製鋼スラグ中の遊離ＣａＯや遊離ＭｇＯを水分と速やかに反応させるのに、昇温と水分供給を同時に行なう蒸気での反応促進（蒸気エージング）が一般的に実施されている。蒸気エージングには、常圧で行われるものと加圧状態で行われるもの（加圧蒸気エージング）があり、常圧の蒸気エージングは、加圧蒸気エージングに較べて処理速度は小さいが、簡易な設備で大量処理が可能である利点がある（例えば、特許文献１）。 In order to rapidly react free CaO and free MgO in steelmaking slag with water, reaction promotion (steam aging) with steam that raises the temperature and supplies water at the same time is generally carried out. There are two types of steam aging, one is performed under normal pressure and the other is performed under pressure (pressurized steam aging). Normal pressure steam aging has a lower processing speed than pressurized steam aging, but is simple. There is an advantage that mass processing is possible in the equipment (for example, Patent Document 1).
製鋼スラグを蒸気エージングするとスラグ粒子の一部は膨張反応で崩壊するため、粒度分布は細かい側に変化する。膨張を抑制しようとして、常圧での蒸気エージングの時間を長くすると、細粒化は進むが膨張性の安定化は鈍る。そうして、路盤材製品の膨張基準を満たすような安定した路盤材を製造するエージング処理の生産性が落ちる。 When steam-aged steelmaking slag, some of the slag particles collapse due to the expansion reaction, so the particle size distribution changes to the finer side. If the steam aging time at normal pressure is lengthened in an attempt to suppress the expansion, the granulation progresses but the stabilization of the expansion becomes slow. As a result, the productivity of the aging process for producing a stable roadbed material that meets the expansion criteria of the roadbed material product is reduced.
したがって本発明の目的は、製鋼スラグを常圧で蒸気エージングして製鋼スラグ路盤材を製造する方法において、膨張性が極めて低い製鋼スラグ路盤材を高い生産性で製造することができる製造方法を提供することにある。 Therefore, an object of the present invention is to provide a manufacturing method capable of manufacturing a steelmaking slag roadbed material having extremely low expandability with high productivity in a method of manufacturing a steelmaking slag roadbed material by steam aging the steelmaking slag at normal pressure. To do.
上記課題を解決するための本発明の要旨は以下のとおりである。
［1］粒径４０ｍｍ以下の割合が８０mass％以上となる粒度に破砕された製鋼スラグ（ａ）について、下記（ｉ）又は（ii）の条件で細粒・微粉分を増減することにより、製鋼スラグ（ａ）の粒度分布をAndreazenの曲線式で近似した場合に、Fuller指数が０．４〜０．６を満足するように製鋼スラグ（ａ）の粒度分布を調整した後、常圧で蒸気エージングを施すことを特徴とする製鋼スラグ路盤材の製造方法。
（ｉ）製鋼スラグ（ａ）の一部について篩目が１０ｍｍ以下の篩（ｘ）で分級することで細粒・微粉分を減じた後、製鋼スラグ（ａ）の残部と混合する。
（ii）以前に、粒径４０ｍｍ以下の割合が８０mass％以上となる粒度に破砕された製鋼スラグを篩目が１０ｍｍ以下の篩（ｘ）で分級することで得られている細粒・微粉分を、製鋼スラグ（ａ）に加えて混合する。
The gist of the present invention for solving the above problems is as follows.
[1] For steelmaking slag (a) crushed to a particle size in which the ratio of
(I) A part of the steelmaking slag (a) is classified with a sieve (x) having a mesh size of 10 mm or less to reduce fine particles and fine powders, and then mixed with the rest of the steelmaking slag (a).
(Ii) Fine particles / fine powder obtained by classifying steelmaking slag previously crushed to a particle size of 80 mass% or more with a particle size of 40 mm or less with a sieve (x) having a mesh size of 10 mm or less. Is added to the steelmaking slag (a) and mixed.
［2］上記［1］の製造方法において、製鋼スラグ（ａ）が同日に同じ精錬設備で発生した脱炭スラグであり、該製鋼スラグ（ａ）の一部について篩目が１０ｍｍ以下の篩（ｘ）で分級することで細粒・微粉分を減じた後、製鋼スラグ（ａ）の残部と混合することにより、製鋼スラグ（ａ）の細粒・微粉分を減少させて粒度分布を調整することを特徴とする製鋼スラグ路盤材の製造方法。
［3］上記［1］の製造方法において、製鋼スラグ（ａ）が２種以上の製鋼スラグからなり、そのなかの１種の製鋼スラグ（ａ1）の全部又は一部について篩目が１０ｍｍ以下の篩（ｘ）で分級することで細粒・微粉分を減じた後、残りの１種以上の製鋼スラグ（ａ2）及び製鋼スラグ（ａ1）の残部（但し、製鋼スラグ（ａ1）の全部を上記分級した場合を除く。）と混合することにより、製鋼スラグ（ａ）の細粒・微粉分を減少させて粒度分布を調整することを特徴とする製鋼スラグ路盤材の製造方法。
[2] In the production method of the above [1], the steelmaking slag (a) is a decarburized slag generated in the same refining facility on the same day, and a part of the steelmaking slag (a) has a sieve mesh of 10 mm or less. After reducing the fine particles and fine powder by classifying with x), the fine particles and fine powder of the steelmaking slag (a) are reduced and the particle size distribution is adjusted by mixing with the rest of the steelmaking slag (a). A method for manufacturing a steelmaking slag roadbed material.
[3] In the manufacturing method of the above [1], the steelmaking slag (a) is composed of two or more types of steelmaking slag, and the sieve mesh is 10 mm or less for all or part of the one type of steelmaking slag (a1). After reducing the fine particles and fine powder by classifying with a sieve (x), the remaining one or more types of steelmaking slag (a2) and the rest of the steelmaking slag (a1) (however, all of the steelmaking slag (a1) are described above. A method for producing a steelmaking slag roadbed material, which comprises reducing the fine particles and fine powders of the steelmaking slag (a) and adjusting the particle size distribution by mixing with (excluding the case of classification).
［4］上記［3］の製造方法において、製鋼スラグ（ａ1）が同日に同じ精錬設備で発生した脱炭スラグであり、製鋼スラグ（ａ2）が脱炭スラグ以外の製鋼スラグであることを特徴とする製鋼スラグ路盤材の製造方法。
［5］上記［1］〜［4］のいずれかの製造方法において、篩（ｘ）の篩目が４ｍｍ以上６ｍｍ以下であることを特徴とする製鋼スラグ路盤材の製造方法。
［6］上記［1］〜［5］のいずれかの製造方法において、常圧で蒸気エージングした後の製鋼スラグの粒度が、ＪＩＳ Ａ５０１５（２０１３）に粒度範囲が定められているＣＳ−４０、ＣＳ−３０、ＣＳ−２０、ＭＳ−２５、ＨＭＳ−２５のいずれかの粒度範囲を満足することを特徴とする製鋼スラグ路盤材の製造方法。
[4] In the manufacturing method of the above [3], the steelmaking slag (a1) is a decarburized slag generated in the same refining facility on the same day, and the steelmaking slag (a2) is a steelmaking slag other than the decarburized slag. A method for manufacturing steelmaking slag roadbed materials.
[5] In any of the above-mentioned production methods [1] to [4], a method for producing a steelmaking slag roadbed material, wherein the sieve (x) has a mesh size of 4 mm or more and 6 mm or less.
[6] In any of the above-mentioned production methods [1] to [5], the grain size of the steelmaking slag after steam aging at normal pressure is defined in JIS A5015 (2013). A method for producing a steelmaking slag roadbed material, which satisfies any one of the particle size ranges of CS-30, CS-20, MS-25, and HMS-25.
本発明によれば、適用したエージング条件で到達し得る最低レベルにまで膨張性を低減した製鋼スラグ路盤材を高い生産性で製造することできる。このため膨張性の製鋼スラグを従来と同じエージング条件や蒸気原単位で蒸気エージングした場合でも、より多くの膨張率合格品（路盤材製品）を得ることができる。また、本発明法で製造された製鋼スラグ路盤材は、膨張性が極めて低いだけでなく、密度が高いため締め固め性にも優れている。 According to the present invention, it is possible to produce a steelmaking slag roadbed material with high productivity in which the expandability is reduced to the lowest level that can be reached under the applied aging conditions. Therefore, even when the expandable steelmaking slag is steam-aged under the same aging conditions and steam intensity as before, more products (roadbed material products) that have passed the expansion coefficient can be obtained. Further, the steelmaking slag roadbed material produced by the method of the present invention not only has extremely low expandability but also has excellent compaction property due to its high density.
以下の説明において、「常圧の蒸気エージング」などという場合のほかに、単に「蒸気エージング」という場合も、常圧（大気圧）で行われる蒸気エージングを意味するものとする。
本発明者は以下のような実験を行った。
路盤材の膨張性評価に用いられる突き固め試験では、条件により突き固め回数が決められている。ＪＩＳ Ａ１２１０（２００９）に定められたＥ−ｂの方法では、内径１５０ｍｍの円筒容器（ＣＢＲ試験型枠）に１層につき４．５ｋｇのランマを９２回落下させて突き、これを３層で突いて高さ１２５ｍｍに突き固める。突き固めた供試体の質量が分かれば、事前に調整した含水比を基にして、乾燥時の供試体質量および密度が求められる。
In the following description, in addition to the case of "normal pressure steam aging", the term "steam aging" also means steam aging performed at normal pressure (atmospheric pressure).
The present inventor conducted the following experiments.
In the tamping test used for evaluating the expandability of roadbed materials, the number of tamping is determined according to the conditions. In the method of Eb specified in JIS A1210 (2009), a 4.5 kg rammer is dropped 92 times per layer into a cylindrical container (CBR test form) having an inner diameter of 150 mm, and the rammer is pierced with three layers. Tighten to a height of 125 mm. Once the mass of the tamped specimen is known, the mass and density of the specimen at the time of drying can be obtained based on the water content ratio adjusted in advance.
標準９２回／層×３層の突き固めを、４６回／層×３層、９２回／層×３層、１８４回／層×３層と変化させて製鋼スラグの突き固めを行い、突き固めた各供試体の乾燥密度を測定した。その結果を図１に示すが、突き固め回数を増やすと乾燥密度は増大している。一方、突き固めた供試体を８０℃に保持した水槽に浸漬して膨張の推移を計測した。図２に、この水浸試験での各供試体の膨張率の推移を示すが、膨張率は密度の小さい順に大きくなっている。すなわち、膨張率は４６回／層＞９２回／層＞１８４回／層となっている。上記３層の突き固めにおいて、１層だけ突き固めた時点の試料を採取し、粒度分布測定した結果を図３に示すが、突き固め回数が１８４回では粗粒が若干崩壊した様子が分かる。 The standard 92 times / layer x 3 layers of compaction is changed to 46 times / layer x 3 layers, 92 times / layer x 3 layers, 184 times / layer x 3 layers to perform compaction of steelmaking slag and compaction. The dry density of each specimen was measured. The result is shown in FIG. 1. As the number of times of tamping is increased, the drying density is increased. On the other hand, the tamped specimen was immersed in a water tank kept at 80 ° C. and the transition of expansion was measured. FIG. 2 shows the transition of the expansion coefficient of each specimen in this water immersion test, and the expansion coefficient increases in ascending order of density. That is, the expansion coefficient is 46 times / layer> 92 times / layer> 184 times / layer. In the above-mentioned three-layer compaction, a sample at the time when only one layer was compacted was collected, and the result of measuring the particle size distribution is shown in FIG. 3. It can be seen that the coarse particles slightly collapsed when the number of compactions was 184 times.
以上の結果は、数多く突き固めて多少粒子が壊れたとしても、密度が高くなるように充填させた方が膨張は小さくなることを示している。
その他これまで、常圧の蒸気エージングの処理時間を４８時間から９６時間まで変化させた種々の条件で試験した水浸膨張試験供試体（製鋼スラグ）について乾燥密度と水浸膨張率（ここでは８０℃一定保持で４日後の膨張率で比較）を調べた結果では、乾燥密度が小さい供試体ほど膨張性が大きい傾向があった。
The above results indicate that even if a large number of particles are tamped and some particles are broken, the expansion becomes smaller when the particles are filled so as to have a higher density.
Others Water immersion expansion test specimens (steelmaking slag) tested under various conditions in which the normal pressure steam aging treatment time was changed from 48 hours to 96 hours Dry density and water immersion expansion rate (80 in this case) As a result of examining the expansion rate after 4 days at a constant temperature, the specimen with a smaller drying density tended to have a larger expansion.
図４は、蒸気エージング（処理時間：７２±２４時間）を施した供試体（製鋼スラグ）の乾燥密度（ＪＩＳ Ａ１２１０（２００９）に定められたＥ−ｂの方法に従い標準９２回／層×３層の突き固めを行って得られた乾燥密度）と水浸膨張率との関係を示しているが、上記と同様の傾向が見られる。
一つのスラグ粒子に注目した場合、充填性が高く周囲の粒子からの拘束が大きいと、粒子の亀裂内にある膨張源が反応して膨張し、粒子自体を膨張させようとしても、拘束されて自由には反応が進まない。膨張反応によって粒子をより破壊して亀裂を進展させれば、反応進行中の膨張源や進展した亀裂先端にある未反応膨張源に水分が到達する空間が広げられる。しかし、粒子周辺の拘束が強いと、水分を膨張源に供給するための空間を容易には広げられず、結果として、膨張反応が抑制される。
FIG. 4 shows a standard 92 times / layer × 3 according to the method of Eb specified in the drying density (JIS A1210 (2009)) of a specimen (steelmaking slag) subjected to steam aging (treatment time: 72 ± 24 hours). The relationship between the dry density obtained by compacting the layers) and the coefficient of water immersion expansion is shown, and the same tendency as above can be seen.
When focusing on one slag particle, if the packing property is high and the constraint from the surrounding particles is large, the expansion source in the crack of the particle reacts and expands, and even if the particle itself is expanded, it is constrained. The reaction does not proceed freely. If the particles are further destroyed by the expansion reaction to develop cracks, the space for water to reach the expansion source during the reaction and the unreacted expansion source at the tip of the expanded crack is expanded. However, if the constraints around the particles are strong, the space for supplying water to the expansion source cannot be easily expanded, and as a result, the expansion reaction is suppressed.
製鋼スラグの密度を高めるには、粗粒が密に配列し、粗粒間に生じる空隙を細粒が埋め、さらに微粉が細粒間に残る空隙を埋めていくのが望ましい。しかし、空隙を埋めるのに必要以上の細粒、微粉があれば、細粒どうしが接して小さな空隙を多数生じるために、結局、最密な充填からは離れていく。蒸気エージングを長くしても、細粒が必要以上に増えてしまえば、スラグ粒子のパッキングを悪化させて、膨張率の低減化を妨げる。 In order to increase the density of the steelmaking slag, it is desirable that the coarse grains are densely arranged, the voids generated between the coarse grains are filled with the fine grains, and the voids remaining between the fine grains are filled. However, if there are more fine particles or fine powders than necessary to fill the voids, the fine particles will come into contact with each other to create many small voids, and as a result, the close-packing will be separated. Even if the steam aging is lengthened, if the number of fine particles increases more than necessary, the packing of slag particles deteriorates and the reduction of the expansion coefficient is hindered.
蒸気エージングを施した種々の製鋼スラグの粒度分布について調べたところ、粒度分布にかなりの差があることが判った。
連続粒度分布の表現についてAndreasenの曲線式があり、最大粒径（Ｄｐmax）に対して各中間径（Ｄｐ）での通過質量分率についてFuller指数ｑを用いて下記（1）式のように表す。
Ｕ（Ｄｐ）＝（Ｄｐ／Ｄｐmax）ｑ …（1）
ここで、Ｄｐは粒径、Ｄｐmaxは最大粒径、Ｕ（Ｄｐ）は粒径Ｄｐまでの通過質量分率である。（出典：例えば「三輪茂雄、粉体工学、日刊工業新聞社、1981年、p.42」）
このAndreasenの曲線は図５のような積算分布になり、細かい粒子が多いほどFuller指数ｑは小さい値となる。実験的には、疎充填ではｑ＝１／２で、密充填ではｑ＝１／３で、それぞれ最も密度が高くなるとされている。
When the particle size distribution of various steam-aged steelmaking slags was investigated, it was found that there was a considerable difference in the particle size distribution.
There is Andreasen's curve equation for the expression of continuous particle size distribution, and the passing mass fraction at each intermediate diameter (Dp) with respect to the maximum particle size (Dpmax) is expressed as the following equation (1) using the Fuller index q. ..
U (Dp) = (Dp / Dpmax) q ... (1)
Here, Dp is the particle size, Dpmax is the maximum particle size, and U (Dp) is the mass fraction passing through to the particle size Dp. (Source: For example, "Shigeo Miwa, Powder Engineering, Nikkan Kogyo Shimbun, 1981, p.42")
This Andreasen curve has an integrated distribution as shown in FIG. 5, and the more fine particles there are, the smaller the Fuller index q becomes. Experimentally, it is said that q = 1/2 for sparse filling and q = 1/3 for dense filling, which are the highest densities.
最大粒径ＤｐmaxとFuller指数ｑを変数として、蒸気エージングを施した種々の製鋼スラグ試料の粒度分布をAndreasenの曲線式で近似した。各試料の突き固め時の乾燥密度（ＪＩＳ Ａ１２１０（２００９）に定められたＥ−ｂの方法に従い標準９２回／層×３層の突き固めを行って得られた乾燥密度）とFuller指数ｑの関係を図６に示す。図６によれば、乾燥密度はｑが０．４〜０．６で最大となり、その前後は小さくなる傾向がある。細粒・微粉が増えるとｑは０．４を下回って、乾燥密度が小さくなる。逆にｑが０．６を上回るのは細粒・微粉を試験的に低減した水準であるが、やはり乾燥密度が小さい。これはｑに充填に最適な範囲があるということであり、Andreasenの曲線式の傾向にも合致している。 With the maximum particle size Dpmax and the Fuller index q as variables, the particle size distributions of various steam-aged steelmaking slag samples were approximated by Andreasen's curve equation. Dry density at the time of compaction of each sample (dry density obtained by compacting standard 92 times / layer × 3 layers according to the method of Eb specified in JIS A1210 (2009)) and Fuller index q. The relationship is shown in FIG. According to FIG. 6, the dry density is maximum when q is 0.4 to 0.6, and tends to be small before and after that. As the number of fine particles and fine powders increases, q falls below 0.4 and the drying density decreases. On the contrary, q exceeds 0.6 at the level where fine particles and fine powders are experimentally reduced, but the drying density is still small. This means that q has an optimum range for filling, which is in line with Andreasen's curvilinear tendency.
製鋼スラグの実際の破砕プラントにおいて、単純に破砕過程及び分級した粗粒の再破砕を経た製品では、細粒・微粉が例えば鉄鋼スラグ路盤材のＪＩＳ規格（ＪＩＳ Ａ５０１５）に照らして必要より少ないことはあまりなく、概ね細かく砕きすぎる場合が多いと考えられる。
さきに挙げた図４において乾燥密度が小さく、膨張が大きかった水準は殆んどｑが０．４未満である。ちなみに常圧で蒸気エージングを施した製鋼スラグの水浸膨張率（８０℃一定保持で４日後の膨張率）とFuller指数ｑとの関係をみると、図７に示すようにｑ＝０．５に向かって水浸膨張率が低下している。
In an actual crushing plant for steelmaking slag, in a product that has undergone a simple crushing process and re-crushing of the classified coarse particles, the amount of fine particles and fine powder should be less than necessary in light of, for example, the JIS standard (JIS A5015) for steel slag roadbed materials. There are not many slags, and it is thought that they are often crushed too finely.
In FIG. 4 mentioned above, the level at which the dry density was small and the expansion was large was that q was less than 0.4. By the way, looking at the relationship between the water immersion expansion rate (expansion rate after 4 days at 80 ° C. constant holding) and the Fuller index q of the steelmaking slag subjected to steam aging at normal pressure, q = 0.5 as shown in FIG. The coefficient of water immersion expansion is decreasing toward.
Fuller指数ｑが０．６より大きくなると、粗粒どうしが接触する頻度が高くなり、粗粒間の空隙を埋める細粒が不足して、充填性が低下する。この場合も粒子間の拘束が低くなり、膨張崩壊をより自由に進められる環境になる。さらに、粗粒ばかりの場合は、ＪＩＳ Ａ５０１５に規定された水浸膨張試験で、試料粒子を型枠の中に突き固める際に、ランマの衝撃を粗粒が直接受ける確率が増し、かつ粗粒に接触している粒子が低充填で少ないため、周囲に応力を分散できなくなって、衝撃を受けた粗粒が高頻度で崩壊する。そうすると、新しい破面に未反応の膨張源が出現するため、蒸気エージングしたにも拘わらず、水浸膨張試験前に多くの未反応膨張源が反応しやすい状況となって、水浸膨張率を上昇させることになる。したがって、粒度を単純に粗粒化すればよい訳でもない。 When the Fuller index q is larger than 0.6, the frequency of contact between the coarse grains increases, the fine grains that fill the voids between the coarse grains are insufficient, and the filling property is lowered. In this case as well, the constraints between the particles are lowered, and the environment is such that expansion and collapse can proceed more freely. Further, in the case of only coarse particles, in the water immersion expansion test specified in JIS A5015, the probability that the coarse particles are directly subjected to the impact of the rammer when the sample particles are compacted into the mold increases, and the coarse particles Since the number of particles in contact with the particle is low and small, the stress cannot be dispersed to the surroundings, and the coarse particles that have been impacted collapse frequently. Then, an unreacted expansion source appears on the new fracture surface, so that many unreacted expansion sources are likely to react before the water immersion expansion test despite steam aging, and the water immersion expansion rate is increased. It will be raised. Therefore, it is not enough to simply coarse-grain the particle size.
以上のことから、本発明者は、蒸気エージングを施した製鋼スラグの水浸膨張は粒度分布によっても影響を受けており、粒度分布が不適切であるためにスラグ粒子の充填性が低下すると、水浸膨張が増大していることを見出した。したがって、望まれる蒸気エージングを実施しても、粒度分布が不適切であることによって膨張性が不合格判定になることが相当数起こっているものと考えられる。
本発明者は、上記知見に基づきさらに検討を進めた結果、所定の条件で事前に細粒・微粉分を増減した製鋼スラグを蒸気エージングすれば、適用したエージング条件で到達し得る最小の膨張率の路盤材が得られることが判った。具体的には、Fuller指数ｑが０．４〜０．６を満足するように粒度分布を調整することが望ましいことが判った。この方法によれば、蒸気エージング前の製鋼スラグの細粒・微粉分を増減するだけでよいため、膨張性が極めて低い製鋼スラグ路盤材を高い生産性で製造することができ、また、製造される製鋼スラグ路盤材は、密度が高いため締め固め性にも優れている。
From the above, the present inventor states that the water immersion expansion of steam-aged steelmaking slag is also affected by the particle size distribution, and that the packing property of the slag particles decreases due to the improper particle size distribution. We found that water immersion expansion was increasing. Therefore, even if the desired steam aging is carried out, it is considered that a considerable number of cases where the expandability is rejected due to the improper particle size distribution occur.
As a result of further studies based on the above findings, the present inventor steam-ages steelmaking slag in which fine particles and fine powders have been increased or decreased in advance under predetermined conditions, and the minimum expansion coefficient that can be reached under the applied aging conditions. It was found that the roadbed material of was obtained. Specifically, it was found that it is desirable to adjust the particle size distribution so that the Fuller index q satisfies 0.4 to 0.6. According to this method, it is only necessary to increase or decrease the fine particles and fine powder content of the steelmaking slag before steam aging, so that the steelmaking slag roadbed material having extremely low expandability can be produced with high productivity, and is also produced. Steelmaking slag roadbed material has high density and is excellent in compaction property.
このため本発明では、粒径４０ｍｍ以下の割合が８０mass％以上となる粒度に破砕された製鋼スラグ（以下、説明の便宜上「製鋼スラグａ」という）について、下記（ｉ）又は（ii）の条件で細粒・微粉分を増減することにより、製鋼スラグａの粒度分布をAndreazenの曲線式で近似した場合に、Fuller指数が０．４〜０．６を満足するように製鋼スラグａの粒度分布を調整した後、常圧で蒸気エージングを施すようにする。なお、粒径４０ｍｍ以下とは篩目が４０ｍｍ（呼び径）の篩を通過する粒径である。
（ｉ）製鋼スラグａの一部について篩目が１０ｍｍ以下の篩（以下、説明の便宜上「篩ｘ」という）で分級することで細粒・微粉分を減じた後、製鋼スラグａの残部（有姿粒度の製鋼スラグａ）と混合する。
（ii）以前に、粒径４０ｍｍ以下の割合が８０mass％以上となる粒度に破砕された製鋼スラグを篩目が１０ｍｍ以下の篩ｘで分級することで得られている細粒・微粉分を、製鋼スラグａ（有姿粒度の製鋼スラグａ）に加えて混合する。
なお、上記（ii）の「以前に・・得られている細粒・微粉分」とは、以前に行われた分級において得られ、ストックされている細粒・微粒分のことである。
製鋼スラグは、鉄鋼製造プロセスの製鋼工程で発生するスラグであり、脱炭スラグ（転炉脱炭スラグ）、溶銑予備処理スラグ（脱珪スラグ、脱燐スラグなど）、造塊スラグ、溶融還元スラグ、電気炉スラグなどがあり、これらの１種以上を用いることができる。
Therefore, in the present invention, the following conditions (i) or (ii) are applied to the steelmaking slag crushed to a particle size in which the ratio of the particle size of 40 mm or less is 80 mass% or more (hereinafter, referred to as “steelmaking slag a” for convenience of explanation). When the particle size distribution of steelmaking slag a is approximated by Andreazen's curve formula by increasing or decreasing the fine grain and fine powder content in, the particle size distribution of steelmaking slag a satisfies the Fuller index of 0.4 to 0.6. After adjusting, steam aging should be performed at normal pressure. The particle size of 40 mm or less is a particle size that passes through a sieve having a mesh size of 40 mm (nominal diameter).
(I) A part of the steelmaking slag a is classified with a sieve having a mesh size of 10 mm or less (hereinafter, referred to as "sieve x" for convenience of explanation) to reduce fine particles and fine powders, and then the rest of the steelmaking slag a (hereinafter referred to as "sieve x"). Mix with tangible grain size steelmaking slag a).
(Ii) Previously, fine-grained and fine-powdered slag obtained by classifying steelmaking slag crushed to a particle size having a particle size of 40 mm or less with a particle size of 80 mass% or more with a sieve x having a mesh size of 10 mm or less was obtained. It is added to and mixed with steelmaking slag a (steelmaking slag a having a tangible particle size).
The "previously obtained fine granules / fine powder" in (ii) above refers to the fine granules / fine particles obtained and stocked in the previously performed classification.
Steelmaking slag is slag generated in the steelmaking process of the steel manufacturing process, and is decarburized slag (converter decarburized slag), hot metal pretreatment slag (desiliconized slag, dephosphorized slag, etc.), ingot slag, and melt reduction slag. , Electric furnace slag, etc., and one or more of these can be used.
本発明において、細粒・微粉分の増減により粒度分布を調整する前の製鋼スラグａについて、その８０mass％以上を占めるスラグの最大粒径を４０ｍｍとしたのは、それより大きい径では内部に残留する膨張源が増加するため、蒸気エージングを施しても水浸膨張率のバラツキが大きくなり、膨張性が安定化しないためである。
Andreazenの曲線式で積算篩下の曲線が大きく変化するのは、Fuller指数ｑが１より小さい領域では粒径が最大粒径の２０％以下の部分と考えられる。篩目４０ｍｍで８０mass％以上通過する粒度分布であれば、最大粒径の２０％の粒径は実質的に１０ｍｍとなり、それ以下の細粒・微粉分の粒子量を調整することが望ましい。このため本発明では、上記（ｉ）、（ii）のように篩目が１０ｍｍ以下の篩ｘで分級することを通じて細粒・微粉分を増減し、粒度分布を調整する。
In the present invention, regarding the steelmaking slag a before adjusting the particle size distribution by increasing or decreasing the fine particles / fine powder content, the maximum particle size of the slag that occupies 80 mass% or more is set to 40 mm, which remains inside if the diameter is larger than that. This is because the number of expansion sources to be increased increases, so that even if steam aging is performed, the variation in the water immersion expansion rate becomes large and the expansion property is not stabilized.
It is considered that the reason why the curve under the integration sieve changes significantly in Andreazen's curve formula is that the particle size is 20% or less of the maximum particle size in the region where the Fuller index q is smaller than 1. If the particle size distribution passes through 80 mass% or more with a mesh of 40 mm, the particle size of 20% of the maximum particle size is substantially 10 mm, and it is desirable to adjust the amount of fine particles and fine particles smaller than that. Therefore, in the present invention, the particle size distribution is adjusted by increasing or decreasing the fine particles and fine powders by classifying with a sieve x having a mesh size of 10 mm or less as in (i) and (ii) above.
また、望まれるFuller指数ｑの１／２近傍では、積算篩下（粒径Ｄｐまでの通過質量分率）の変化が大きいのは粒径が最大粒径の約１０％以下（すなわち約４〜６ｍｍ以下）の部分であり、直接的に４〜６ｍｍ以下の粒子を増減することが粒度分布を操作しやすい。このため本発明では、上記（ｉ）、（ii）の篩ｘの篩目を４〜６ｍｍとし、その篩目を通過する粒径４〜６ｍｍ以下の細粒・微粉分の増減を行うことが好ましい。例えば、篩ｘの篩目を５ｍｍ（呼び径）とし、その篩目を通過する粒径５ｍｍ以下の細粒・微粉分の増減を行うものである（なお、以下の説明において「粒径５ｍｍ以下」、「−５ｍｍ」とは篩目５ｍｍ（呼び径）を通過する粒径のことである。）。すなわち、上記（ｉ）のように細粒・微粉分を減じる場合には、例えば、対象となる製鋼スラグａの山（同日に同じ精錬設備で発生した製鋼スラグ）の一部だけ篩目が５ｍｍ（呼び径）の篩ｘで分級することで粒径５ｍｍ以下の粒子を分離し、残りの山の部分（製鋼スラグａの残部）は分級することなく有姿粒度のままとし、分級した製鋼スラグａと分級しない有姿粒度のままの製鋼スラグａを混合する。この場合、篩目が５ｍｍの篩ｘで分級する製鋼スラグａの割合を変えることで、全体での粒径５ｍｍ以下の細粒・微粉分の割合を調整できる。一方、５ｍｍ以下の粒子が不足し、上記（ii）のように不足する細粒・微粉分を増やす場合には、それ以前の分級で篩い出したストックの−５ｍｍ分（粒径４０ｍｍ以下の割合が８０mass％以上となる粒度に破砕された製鋼スラグを篩目が５ｍｍ（呼び径）の篩ｘで分級して得られている細粒・微粉分）を必要なだけ加え、混合する。そして、以上のような粒度分布の調整により、Fuller指数ｑが０．４〜０．６を満足するようにする。
製鋼スラグのなかでも脱炭スラグは、比較的高塩基度（ＣａＯ／ＳｉＯ２）で、遊離ＣａＯの含有量も高いことから、粒径５ｍｍ以下のスラグ粒子は、例えば焼結原料や精錬の造滓材にリサイクル使用することもできるため、積極的に分級して取り出す利点も有している。
Further, in the vicinity of 1/2 of the desired Fuller index q, the change in the integrated sieve (passing mass fraction up to the particle size Dp) is large when the particle size is about 10% or less of the maximum particle size (that is, about 4 to about 4 to). It is a part of 6 mm or less), and it is easy to manipulate the particle size distribution by directly increasing or decreasing the particles of 4 to 6 mm or less. Therefore, in the present invention, the mesh of the sieve x of the above (i) and (ii) is set to 4 to 6 mm, and the fine particles and fine powders having a particle size of 4 to 6 mm or less passing through the mesh can be increased or decreased. preferable. For example, the mesh of the sieve x is set to 5 mm (nominal diameter), and the fine particles and fine powders having a particle size of 5 mm or less passing through the mesh are increased or decreased (note that in the following description, "particle size of 5 mm or less". "," -5 mm "means a particle size that passes through a mesh of 5 mm (nominal diameter).) That is, when reducing the fine particles and fine powders as in (i) above, for example, only a part of the target steelmaking slag a pile (steelmaking slag generated in the same refining facility on the same day) has a sieve mesh of 5 mm. By classifying with a sieve x of (nominal diameter), particles with a particle size of 5 mm or less are separated, and the remaining mountain part (the rest of the steelmaking slag a) is left as the tangible grain size without being classified, and the classified steelmaking slag. The steelmaking slag a with the tangible grain size that is not classified is mixed with a. In this case, by changing the ratio of the steelmaking slag a classified by the sieve x having a mesh size of 5 mm, the ratio of the fine particles / fine powder having a particle size of 5 mm or less can be adjusted as a whole. On the other hand, when particles of 5 mm or less are deficient and the deficient fine particles / fine particles are increased as in (ii) above, the amount of stock sieved by the previous classification is -5 mm (ratio of particle size of 40 mm or less). Steelmaking slag crushed to a particle size of 80 mass% or more is classified with a sieve x having a mesh size of 5 mm (nominal diameter), and fine particles and fine particles obtained by classifying the slag are added as necessary and mixed. Then, by adjusting the particle size distribution as described above, the Fuller index q is made to satisfy 0.4 to 0.6.
Among steelmaking slags, decarburized slag has a relatively high basicity (CaO / SiO 2 ) and a high content of free CaO. Therefore, slag particles having a particle size of 5 mm or less are, for example, sintered raw materials or refined products. Since it can be recycled as slag material, it also has the advantage of being actively classified and taken out.
製鋼スラグ路盤材には２種以上の製鋼スラグを混合して用いることも可能である。このように製鋼スラグａが２種以上の製鋼スラグからなる場合には、そのなかの１種の製鋼スラグａ1の全部又は一部について篩目が１０ｍｍ以下の篩ｘ（例えば、篩目が呼び径５ｍｍの篩ｘ）で分級することで細粒・微粉分を減じた後、分級しない有姿粒度のままの残りの１種以上の製鋼スラグａ2及び製鋼スラグａ1の残部（但し、製鋼スラグａ1の全部を上記分級した場合を除く。）と混合することにより粒度分布を調整するようにしてもよい。この場合、（1）篩目が１０ｍｍ以下の篩ｘ（例えば、篩目が呼び径５ｍｍの篩ｘ）で分級する製鋼スラグａ1の割合を変えること、（2）製鋼スラグａ1と製鋼スラグａ2の量比を変えること、のいずれか又は両方により、全体での粒径５ｍｍ以下の細粒・微粉分の割合を調整できる。そして、以上のような粒度分布の調整により、Fuller指数ｑが０．４〜０．６を満足するようにする。
上記のように製鋼スラグ路盤材に２種以上の製鋼スラグを混合して用いる場合の代表例は、製鋼スラグａ1が同日に同じ精錬設備で発生した脱炭スラグであり、製鋼スラグａ2が脱炭スラグ以外の製鋼スラグである場合である。
Steelmaking slag It is also possible to use a mixture of two or more types of steelmaking slag for the roadbed material. In this way, when the steelmaking slag a is composed of two or more types of steelmaking slag, a sieve x (for example, the mesh size has a nominal diameter) having a mesh size of 10 mm or less for all or part of one type of steelmaking slag a1. After reducing fine particles and fine powder by classifying with a 5 mm sieve x), the remaining one or more types of steelmaking slag a2 and steelmaking slag a1 (however, the steelmaking slag a1) remain unclassified and have tangible grain size. The particle size distribution may be adjusted by mixing all of them with the above-mentioned classification). In this case, (1) the ratio of the steelmaking slag a1 to be classified by the sieve x having a mesh size of 10 mm or less (for example, the sieve x having a nominal diameter of 5 mm) is changed, and (2) the steelmaking slag a1 and the steelmaking slag a2 By changing the amount ratio, or both, the ratio of fine particles / fine powder having a particle size of 5 mm or less can be adjusted as a whole. Then, by adjusting the particle size distribution as described above, the Fuller index q is made to satisfy 0.4 to 0.6.
A typical example of the case where two or more types of steelmaking slag are mixed and used in the steelmaking slag roadbed material as described above is that the steelmaking slag a1 is a decarburized slag generated in the same refining facility on the same day, and the steelmaking slag a2 is decarburized. This is a case of steelmaking slag other than slag.
本発明において、Fuller指数ｑが０．４〜０．６を満足するように粒度分布を調整するのは蒸気エージング前の製鋼スラグａである。製鋼スラグａの粒度は、蒸気エージングを施すと細粒・微粉が増えるが、同時に粗粒が低減することによりAndreasenの曲線式における最大粒径が低下するので、粒度分布の形はさほど変化しない。このため蒸気エージングを施した後の製鋼スラグａ（路盤材製品）のFuller指数ｑも概ね０．４〜０．６の範囲に維持される。但し、蒸気エージングにより全体的には細粒化するにもかかわらず、最大粒径が低下することにより、Fuller指数が増大することもある。このため、望ましくはFuller指数ｑが０．５近傍（０．５±０．０５）となるように粒度分布を調整した上で、蒸気エージングすることがより好ましい。 In the present invention, it is the steelmaking slag a before steam aging that adjusts the particle size distribution so that the Fuller index q satisfies 0.4 to 0.6. As for the particle size of the steelmaking slag a, fine particles and fine powders increase when steam aging is applied, but at the same time, the maximum particle size in Andreasen's curve formula decreases due to the reduction of coarse particles, so the shape of the particle size distribution does not change so much. Therefore, the Fuller index q of the steelmaking slag a (roadbed material product) after steam aging is also maintained in the range of approximately 0.4 to 0.6. However, the Fuller index may increase due to the decrease in the maximum particle size, although the particles are generally finely divided by steam aging. Therefore, it is more preferable that the particle size distribution is adjusted so that the Fuller index q is close to 0.5 (0.5 ± 0.05), and then steam aging is performed.
上述したスラグの混合、すなわち、分級した製鋼スラグａと分級しない有姿粒度のままの製鋼スラグａの混合や、製鋼スラグａ1と製鋼スラグａ2の混合は、蒸気エージング前に行う必要がある。蒸気エージング後に重機や混合機を用いてスラグ粒子を均一に混合しようとすると、スラグ粒子に機械的応力が作用して、再度崩壊したり、膨張反応が終了した粒子表面を引っ掻いたり、削ったりして未反応膨張源を出現させる。その結果、水浸膨張率が上昇したり、バラツキが大きくなり、製品として不合格判定となる比率が増大する。 The above-mentioned mixing of the slags, that is, the mixing of the classified steelmaking slag a and the steelmaking slag a having an unclassified tangible grain size, and the mixing of the steelmaking slag a1 and the steelmaking slag a2 must be performed before steam aging. When slag particles are uniformly mixed using a heavy machine or a mixer after steam aging, mechanical stress acts on the slag particles, causing them to collapse again, or to scratch or scrape the surface of the particles after the expansion reaction. To make an unreacted expansion source appear. As a result, the coefficient of thermal expansion in water increases, the variation increases, and the ratio of rejected products increases.
蒸気エージングの処理時間は２４〜１４４時間程度が適当である。ここで、処理時間とは、山積みされたスラグベッドの昇温期間（測温している温度計がほぼ１００℃に達するまで）が終わってからの約１００℃での保温時間をいう。処理時間の望ましい上限を１４４時間としたのは、処理時間が長すぎると生産性が低下するからである。また、処理時間の望ましい下限を２４時間としたのは、蒸気が吹き込まれた山積みスラグが均一に昇温して反応促進するには、最低でも２４時間は必要だからである。 The appropriate steam aging treatment time is about 24 to 144 hours. Here, the processing time refers to the heat retention time at about 100 ° C. after the temperature rise period (until the thermometer measuring the temperature reaches approximately 100 ° C.) of the piled up slag beds is completed. The desirable upper limit of the processing time is 144 hours because if the processing time is too long, the productivity decreases. Further, the desirable lower limit of the treatment time is set to 24 hours because at least 24 hours is required for the piled slag in which the steam is blown to uniformly raise the temperature and promote the reaction.
本発明法において蒸気エージングした後の製鋼スラグの粒度は、ＪＩＳ Ａ５０１５（２０１３）に粒度範囲が定められているＣＳ−４０、ＣＳ−３０、ＣＳ−２０、ＭＳ−２５、ＨＭＳ−２５のいずれかの粒度範囲を満足することが好ましい。これらは道路用鉄鋼スラグの粒度を含めた物性を規定したものであり、規格名の数字は概ねの最大粒径を示している。実用上はこの粒度を満たすものが道路舗装工事に用いられるため、路盤材用途の販売にはこの規格に合格する必要がある。
以上のような本発明法で製造される製鋼スラグ路盤材は、粒度分布をAndreazenの曲線式で近似した場合に、Fuller指数が０．４〜０．６となる粒度分布を有することが好ましい。
本発明により製造された製鋼スラグ路盤材は、単独で使用（施工）してもよいし、他の路盤材料（例えば、他のスラグ路盤材や砕石など）と混合して使用（施工）してもよい。
The particle size of the steelmaking slag after steam aging in the method of the present invention is any one of CS-40, CS-30, CS-20, MS-25, and HMS-25 whose particle size range is defined in JIS A5015 (2013). It is preferable to satisfy the particle size range of. These specify the physical properties including the particle size of steel slag for roads, and the numbers in the standard name indicate the approximate maximum particle size. Practically, those that meet this granularity are used for road pavement work, so it is necessary to pass this standard for sales of roadbed materials.
The steelmaking slag roadbed material produced by the method of the present invention as described above preferably has a particle size distribution in which the Fuller index is 0.4 to 0.6 when the particle size distribution is approximated by Andreazen's curve formula.
The steel-making slag roadbed material produced by the present invention may be used (constructed) alone or mixed with other roadbed materials (for example, other slag roadbed materials and crushed stones). May be good.
原料となる製鋼スラグは、脱炭スラグと造塊スラグであり、いずれも粒径４０ｍｍ以下に破砕されたもの（篩目４０ｍｍ（呼び径）の篩を通過したもの）である。遊離ＣａＯ含有量は、脱炭スラグが４．９〜５．２mass％、造塊スラグが１．３mass％であった。実施例１及び実施例２では、脱炭スラグとして、篩目が５ｍｍ（呼び径）の篩で−５ｍｍの粒子を分級・排除したスラグＡ（粒度５−４０ｍｍ）と、このスラグＡと同日に同じ精錬設備で発生した脱炭スラグであって、分級せずに−５ｍｍの粒子をそのまま含む有姿粒度のスラグＢ（粒度０−４０ｍｍ）を用いた。また、実施例２では、造塊スラグとして、分級せずに−５ｍｍの粒子をそのまま含む有姿粒度のスラグＣ（粒度０−４０ｍｍ）を用いた。また、実施例３では、脱炭スラグとして、分級されていない有姿粒度のスラグＤ（粒度０−４０ｍｍ）と、以前に、粒径４０ｍｍ以下に破砕された脱炭スラグを篩目が５ｍｍ（呼び径）の篩で分級した際に篩下となり、ストックされていたスラグＥ（粒度０−５ｍｍ）を用いた。なお、スラグＤは粒度０−４０ｍｍであるが、全体的に粒度が粗く、細粒分が少ない粒度分布のスラグである。
スラグＡ〜Ｅのうちの２つのスラグを混合する際には、スラグの混合にホイルローダー等の重機を用い、切り返しを数度繰り返すことで混合を均一化した。
The steelmaking slag used as a raw material is decarburized slag and ingot slag, both of which are crushed to a particle size of 40 mm or less (passed through a sieve having a mesh size of 40 mm (nominal diameter)). The free CaO content was 4.9 to 5.2 mass% for decarburized slag and 1.3 mass% for ingot slag. In Examples 1 and 2, as decarburized slag, slag A (particle size 5-40 mm) obtained by classifying and eliminating -5 mm particles with a sieve having a sieve size of 5 mm (nominal diameter) and slag A (particle size 5-40 mm) on the same day as the slag A. Decarburized slag generated in the same refining facility, slag B (grain size 0-40 mm) having a tangible particle size containing -5 mm particles as it was was used without classification. Further, in Example 2, as the ingot slag, slag C (grain size 0-40 mm) having a tangible particle size containing -5 mm particles as it was was used without classification. Further, in Example 3, as the decarburized slag, the unclassified tangible particle size slag D (particle size 0-40 mm) and the previously crushed decarburized slag having a particle size of 40 mm or less are sieved to 5 mm (mesh size). When the slag was classified with a sieve having a nominal diameter), it became under the sieve, and the stocked slag E (particle size 0-5 mm) was used. Although the slag D has a particle size of 0 to 40 mm, it is a slag having a particle size distribution that is coarse as a whole and has a small amount of fine particles.
When mixing two slags A to E, a heavy machine such as a wheel loader was used to mix the slags, and the slags were cut back several times to make the mixing uniform.
スラグの通過質量分率（粒度分布）を測定するのに、３７．５ｍｍ（呼び径４０ｍｍ）、３１．５ｍｍ、２６．５ｍｍ、１９．０ｍｍ、１３．０ｍｍ、９．５ｍｍ（呼び径１０ｍｍ）、４．７５ｍｍ（呼び径５ｍｍ）、２．３６ｍｍ、１．１８ｍｍ、０．６ｍｍ、０．４２５ｍｍ、０．３ｍｍ、０．１５ｍｍ、０．０７５ｍｍの篩を用いた。この篩系列は、骨材粒度を測定する篩系列とスラグ路盤材の粒度を測定する篩系列の折衷となっている。これは、スラグ路盤材の篩系列よりも細粒側の分布を精密に測定するためである。ＪＩＳ Ａ５０１５（２０１３）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、実操業では製品中のバラツキがあることを考慮して、より小さな膨張率にまで安定化することがよく行われる。本実施例では、蒸気エージング後のスラグ単味で水浸膨張率を０．５％以下にまで低減することを目安とした。
蒸気エージングは、１．５ｍ層厚で山積みしたスラグの下方から蒸気を吹き込んで昇温するエージング設備で約１００℃に達してから７２時間保持する条件で実施した。
To measure the passing mass fraction (particle size distribution) of slag, 37.5 mm (
Steam aging was carried out under the condition of holding for 72 hours after reaching about 100 ° C. in an aging facility in which steam was blown from below a pile of slags having a thickness of 1.5 m to raise the temperature.
［実施例１］
比較例１を除き、−５ｍｍの細粒分を分級・排除したスラグＡ（粒度５−４０ｍｍ）と、−５ｍｍの細粒分を分級・排除していない有姿粒度のスラグＢ（粒度０−４０ｍｍ）を混合し、所定の粒度分布を有するスラグ（試料）とした。なお、比較例１は、有姿粒度のスラグＢ（粒度０−４０ｍｍ）のみからなるスラグ（試料）を対象とした。これら蒸気エージング前のスラグについて、Andreasenの曲線式におけるFuller指数ｑをグラフソフトの回帰機能を用いて求めた。その一例を図８に示す。その際、通過質量分率１００mass％、すなわち全通となる篩目の通過質量分率はデータとせず、通過質量分率１００mass％未満の篩目での通過質量分率のみをデータとして近似した。
各スラグに対して常圧で蒸気エージングを施した後、再度、粒度分布測定とFuller指数ｑの算出を行った。また、蒸気エージング後のスラグについてＪＩＳ Ａ５０１５（２０１３）附属書２に定めた水浸膨張試験を行い、各供試体の乾燥密度と水浸膨張率を測定した。
[Example 1]
Except for Comparative Example 1, slag A (particle size 5-40 mm) in which -5 mm fine particles were classified / excluded and slag B (particle size 0-) in which -5 mm fine particles were not classified / excluded. 40 mm) was mixed to obtain a slag (sample) having a predetermined particle size distribution. In Comparative Example 1, a slag (sample) consisting of only slag B (particle size 0-40 mm) having a tangible particle size was targeted. For these slags before steam aging, the Fuller index q in Andreasen's curve equation was calculated using the regression function of the graph software. An example thereof is shown in FIG. At that time, the passing mass fraction of 100 mass%, that is, the passing mass fraction of the entire mesh was not used as data, and only the passing mass fraction of the mesh having a passing mass fraction of less than 100 mass% was approximated as data.
After steam aging of each slag at normal pressure, the particle size distribution was measured and the Fuller index q was calculated again. In addition, the slag after steam aging was subjected to a water immersion expansion test specified in
それらの結果を表１及び表２に示す。なお、表１及び表２に記載された最大粒径Ｄｐmaxは、各スラグの粒度分布をAndreazenの曲線式で近似したときに、フィッティングした曲線から求まるスラグの最大粒径（スラグが全通となる計算上の篩目）である。表３〜表６に記載された最大粒径Ｄｐmaxについても同様である。
表１及び表２によれば、Fuller指数ｑが０．４〜０．６の範囲にある発明例１〜３は、水浸膨張供試体の乾燥密度が高く、水浸膨張率が比較例に比べて低い。これに対して、Fuller指数ｑが０．４より小さい比較例１、２と、Fuller指数ｑが０．６より大きい比較例３、４では、発明例と同じ由来のスラグであっても水浸膨張率は高い。
The results are shown in Tables 1 and 2. The maximum particle size Dpmax shown in Tables 1 and 2 is the maximum particle size of the slag obtained from the fitted curve when the particle size distribution of each slag is approximated by Andreazen's curve formula (the slag is the entire size). (Calculation mesh). The same applies to the maximum particle size Dpmax shown in Tables 3 to 6.
According to Tables 1 and 2, in Invention Examples 1 to 3 in which the Fuller index q is in the range of 0.4 to 0.6, the drying density of the water immersion expansion specimen is high, and the water immersion expansion rate is a comparative example. Low compared to. On the other hand, in Comparative Examples 1 and 2 in which the Fuller index q is smaller than 0.4 and Comparative Examples 3 and 4 in which the Fuller index q is larger than 0.6, even slag derived from the same origin as the invention example is flooded. The expansion rate is high.
［実施例２］
脱炭スラグであるスラグＡ（粒度５−４０ｍｍ）又はスラグＢ（粒度０−４０ｍｍ）と、造塊スラグであるスラグＣ（粒度０−４０ｍｍ）を混合し、所定の粒度分布を有するスラグ（試料）とした。これら蒸気エージング前のスラグについて、実施例１と同様の方法でFuller指数ｑを求めた。また、各スラグに対して常圧で蒸気エージングを施した後、実施例１と同様の方法で粒度分布測定とFuller指数ｑの算出を行うとともに、各供試体の乾燥密度と水浸膨張率を測定した。なお、スラグＡは−５ｍｍ分を排除したものであるが、実際の製造では、完全には排除できずに、−５ｍｍ分を少量含んでいる。
また、比較のためにスラグＡ、スラグＢ、スラグＣにそれぞれ単味で常圧の蒸気エージングを施し、同様に蒸気エージング処理後の粒度分布測定とFuller指数ｑの算出を行うとともに、各供試体の乾燥密度と水浸膨張率を測定した。
[Example 2]
Slag A (particle size 5-40 mm) or slag B (particle size 0-40 mm), which is a decarburized slag, and slag C (particle size 0-40 mm), which is an ingot slag, are mixed and slag having a predetermined particle size distribution (sample). ). For these slags before steam aging, the Fuller index q was determined by the same method as in Example 1. Further, after steam aging of each slag at normal pressure, the particle size distribution is measured and the Fuller index q is calculated by the same method as in Example 1, and the drying density and the coefficient of thermal expansion of each specimen are measured. It was measured. Although slag A is obtained by removing -5 mm, it cannot be completely removed in actual production and contains a small amount of -5 mm.
Further, for comparison, slag A, slag B, and slag C are each subjected to a single normal pressure steam aging, and similarly, the particle size distribution after the steam aging treatment and the calculation of the Fuller index q are performed, and each specimen is tested. The dry density and water immersion expansion rate of the slag were measured.
それらの結果を表３及び表４に示す。これによれば、−５ｍｍの細粒分を分級・排除していない有姿粒度のスラグＢ（粒度０−４０ｍｍ）とスラグＣ（粒度０−４０ｍｍ）を５０：５０（質量比）で混合した比較例５はFuller指数ｑが０．４より小さい。一方、−５ｍｍの細粒分を分級・排除したスラグＡ（粒度５−４０ｍｍ）とスラグＣ（粒度０−４０ｍｍ）を５０：５０（質量比）で混合した発明例４はFuller指数ｑが０．４〜０．６の範囲内にある。ここで、スラグＡ、Ｂ、Ｃをそれぞれ単味で使用した場合をみると、スラグＣは遊離ＣａＯが少ないために、膨張安定化が速やかに起こり、蒸気エージング後の水浸膨張率は０．２３％と低い。一方、脱炭スラグであるスラグＡとスラグＢは元々遊離ＣａＯ量がスラグＣよりも多く、またFuller指数ｑはともに０．４〜０．６の範囲から外れており、供試体の乾燥密度が低く、水浸膨張率は０．５％よりも高い。発明例４の場合、供試体の乾燥密度が高く、水浸膨張率はスラグＢとスラグＣの水浸膨張率平均より低い値となっており、粒度分布の調整による効果が現れている。 The results are shown in Tables 3 and 4. According to this, slag B (particle size 0-40 mm) and slag C (particle size 0-40 mm) having a tangible particle size that did not classify and exclude fine particles of -5 mm were mixed at a ratio of 50:50 (mass ratio). In Comparative Example 5, the Fuller index q is smaller than 0.4. On the other hand, Invention Example 4 in which slag A (particle size 5-40 mm) and slag C (particle size 0-40 mm) obtained by classifying and excluding fine particles of -5 mm are mixed at a ratio of 50:50 (mass ratio) has a Fuller index q of 0. It is in the range of .4 to 0.6. Here, when slags A, B, and C are used alone, slag C has a small amount of free CaO, so expansion stabilization occurs rapidly, and the coefficient of water immersion expansion after steam aging is 0. It is as low as 23%. On the other hand, the decarburized slags slag A and slag B originally have a larger amount of free CaO than slag C, and the Fuller index q is both out of the range of 0.4 to 0.6, so that the dry density of the specimen is high. It is low and the water immersion expansion rate is higher than 0.5%. In the case of Invention Example 4, the drying density of the specimen is high, and the water immersion expansion coefficient is lower than the average of the water immersion expansion rates of slag B and slag C, and the effect of adjusting the particle size distribution appears.
[実施例３]
いずれも脱炭スラグである有姿粒度のスラグＤ（粒度０−４０ｍｍ）と篩目５ｍｍの篩下のスラグＥ（粒度０−５ｍｍ）を混合し、所定の粒度分布を有するスラグ（試料）とした。この蒸気エージング前のスラグについて、実施例１と同様の方法でFuller指数ｑを求めた。また、スラグに対して常圧で蒸気エージングを施した後、実施例１と同様の方法で粒度分布測定とFuller指数ｑの算出を行うとともに、供試体の乾燥密度と水浸膨張率を測定した。
また、比較のためにスラグＤ単味について、実施例１と同様の方法でFuller指数ｑを求めた。さらに、スラグＤ単味で常圧の蒸気エージングを施し、同様に蒸気エージング処理後の粒度分布測定とFuller指数ｑの算出を行うとともに、乾燥密度と水浸膨張率を測定した。
[Example 3]
A slag D (particle size 0-40 mm) with a tangible particle size, which is a decarburized slag, and a slag E (particle size 0-5 mm) under a sieve with a mesh size of 5 mm are mixed to form a slag (sample) having a predetermined particle size distribution. did. For the slag before steam aging, the Fuller index q was determined by the same method as in Example 1. Further, after steam aging the slag at normal pressure, the particle size distribution was measured and the Fuller index q was calculated by the same method as in Example 1, and the drying density and the coefficient of thermal expansion of the specimen were measured. ..
Further, for comparison, the Fuller index q was determined for the slag D simple taste by the same method as in Example 1. Further, normal pressure steam aging was applied to the slag D alone, and the particle size distribution after the steam aging treatment was measured and the Fuller index q was calculated, and the dry density and the water immersion expansion rate were measured.
それらの結果を表５及び表６に示す。これによれば、細粒分がやや少ない有姿粒度のスラグＤ（粒度０−４０ｍｍ）はFuller指数ｑが０．６より大きい。これに対して、有姿粒度のスラグＤに細粒のスラグＥ（粒度０−５ｍｍ）を８５：１５（質量比）で混合した発明例５は、Fuller指数ｑが０．４〜０．６の範囲内にある。蒸気エージング後の粒度分布でも、スラグＤはFuller指数ｑが０．６より大きいが、発明例５はFuller指数ｑが０．４〜０．６の範囲内にある。また、発明例５は、スラグＤに較べて乾燥密度が高く、水浸膨張率は０．５％を下回っている。 The results are shown in Tables 5 and 6. According to this, the slag D (particle size 0-40 mm) having a tangible particle size with a slightly smaller fine particle content has a Fuller index q larger than 0.6. On the other hand, in Invention Example 5 in which fine-grained slag E (grain size 0-5 mm) is mixed with tangible particle size slag D at an 85:15 (mass ratio), the Fuller index q is 0.4 to 0.6. Is within the range of. Even in the particle size distribution after steam aging, the slag D has a Fuller index q larger than 0.6, but Invention Example 5 has a Fuller index q in the range of 0.4 to 0.6. Further, in Invention Example 5, the dry density is higher than that of the slag D, and the water immersion expansion rate is less than 0.5%.
Claims (6)
（ｉ）製鋼スラグ（ａ）の一部について篩目が１０ｍｍ以下の篩（ｘ）で分級することで細粒・微粉分を減じた後、製鋼スラグ（ａ）の残部と混合する。
（ii）以前に、粒径４０ｍｍ以下の割合が８０mass％以上となる粒度に破砕された製鋼スラグを篩目が１０ｍｍ以下の篩（ｘ）で分級することで得られている細粒・微粉分を、製鋼スラグ（ａ）に加えて混合する。 With respect to the steelmaking slag (a) crushed to a particle size in which the ratio of the particle size of 40 mm or less is 80 mass% or more, the steelmaking slag (a) is increased or decreased under the conditions of the following (i) or (ii). When the particle size distribution of)) is approximated by Andreazen's curve formula, the particle size distribution of the steelmaking slag (a) is adjusted so that the Fuller index satisfies 0.4 to 0.6, and then steam aging is performed at normal pressure. A method for manufacturing a steelmaking slag roadbed material.
(I) A part of the steelmaking slag (a) is classified with a sieve (x) having a mesh size of 10 mm or less to reduce fine particles and fine powders, and then mixed with the rest of the steelmaking slag (a).
(Ii) Fine particles / fine powder obtained by classifying steelmaking slag previously crushed to a particle size of 80 mass% or more with a particle size of 40 mm or less with a sieve (x) having a mesh size of 10 mm or less. Is added to the steelmaking slag (a) and mixed.
The particle size of the steelmaking slag after steam aging at normal pressure is one of CS-40, CS-30, CS-20, MS-25, and HMS-25, the particle size range of which is defined in JIS A5015 (2013). The method for producing a steelmaking slag roadbed material according to any one of claims 1 to 5, wherein the particle size range is satisfied.
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| JPS60250103A (en) * | 1984-05-24 | 1985-12-10 | 株式会社神戸製鋼所 | Hydraulic road material |
| JPS6158849A (en) * | 1984-08-28 | 1986-03-26 | 株式会社神戸製鋼所 | Method and apparatus for accelerating steel slag ageing |
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