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    • 专利摘要:
    Method for solidifying liquid steel slag »Liquid steel slag (2) is poured in at least four successive layers (6-8), comprising a lower layer (6), an upper layer (7) and at least two intermediate layers (8), in a tank (3) and the layers of liquid steel slag are allowed to cool. After applying the top layer (7), the solidified steel slag is cooled more quickly by means of water. The average temperature of each of the intermediate layers (8) is maintained at least until the start of the water cooling step, and this for at least one hour, above a minimum temperature which is equal to or greater than the temperature at which dicalcium-fi silicate is formed. In this way, more crystal phases different from the dicalcium silicates are formed so that the formation of fines due to the transition from dicalcium silicate R to dicalcium silicate can be greatly reduced. A glassy material and / or a phosphorus-containing compound is preferably added to the liquid slag to further reduce the formation of fines. Figure 1.
    公开号:BE1022642B1
    申请号:E2015/5195
    申请日:2015-03-27
    公开日:2016-06-23
    发明作者:Mechelen Dirk Van；Frédérique Bouillot；Sandhya Sharma；Marie-Paule Delplancke
    申请人:Recoval Belgium；Université Libre de Bruxelles；
    IPC主号:
    专利说明:

    "Process for solidifying liquid steel slag"
    The present invention relates to a process for solidifying liquid steel slag to produce solid steel slag, particularly solid steel slag which can be used after crushing as a granulate in the construction. steps of pouring at least four successive layers of said liquid steel slag comprising a bottom layer, an upper layer and at least two intermediate layers and cooling the solidified steel slag in the reservoir by applying water to these layers; Liquid steel slag comprises at least the elements calcium, silicon and oxygen and has a basicity, defined as the ratio between their calcium content, expressed as% by weight of CaO, and their silicon content, expressed as% by weight of SiO2, which is greater than 1.2 so that when they are slowly cooled, at a cooling rate for example of about 10 C / min, dicalcium silicate-ß is formed therein from a first temperature.
    The steel slags are slags of calcium silicate which contain in particular dicalcium silicates but also other silicates such as, for example, calcium and magnesium silicates. A problem with these calcium silicate slags is that, during their cooling, for example in the open air, a large number of them disintegrate into a fine powder. This is due to the formation of crystalline phases of dicalcium silicate (C2S) which undergo several phase transformations during slag cooling. The last transformation, which is the transformation of β into polymorph γ, occurs at about 490 ° C, and is accompanied by a volume expansion of 12%. This expansion causes high internal stresses in the slag and consequently the disintegration of solid slag into a fine powder. Unlike large pieces of solid steel slag that can be crushed to produce aggregate that can be used in building materials such as concrete and asphalt, fines can not be used as such in these applications. among other things, because of their high water absorption properties, and are therefore difficult to value.
    As described, for example, in the paper "Options to prevent dicalcium silicate-driven disintegration of stainless steel slags" by Y. Pontikes et al., Volume 55, Number 4, we already know of several potential routes to avoid These potential pathways include the chemical stabilization of slag by additions such as borates and phosphates, the change of slag chemistry by addition of glass waste and cooling (quenching or granulation) of The addition of borates and phosphates can prevent the transition of β to polymorph-γ of the dicalcium silicate or at least reduce the amount of polymorph γ that is still formed, but a disadvantage of borates is their relatively high cost. In addition, it has been found that borates are toxic so that they are or will be banned in at least a number of countries. for example, the addition of borates poses a major problem for the stabilization of stainless steel slags due to the validity of REACH (EC Regulation No. 1907/2006 concerning the registration, evaluation, authorization of chemical substances and the restrictions applicable to these substances). Borates are considered to be toxic for reproduction and are included in the list of CMR substances (carcinogenic, mutagenic or toxic for reproduction). It is necessary to use larger quantities of phosphates than borates and this therefore also implies a relatively high additional cost.
    By adding glass waste or any other material that contains a large amount of silica such as quartz or fly ash, it is possible to change the chemistry of steel slag, that is to say it is possible to reduce their basicity so as to avoid the presence of C2S. To avoid the formation of C2S, slag composition should conform to one of the following relationships:
    To satisfy one or the other of these relationships, a very large quantity of glass waste must be added. (In "Effects of MgO based on the addition of stainless steel slag" in Current Advance Material and Processes, 14 (4): 939, 2001) Sakamoto showed, for example, on a laboratory scale that Decarbonation of stainless steel could be stabilized with 12% by weight of glass waste containing 70-75% by weight of SiO 2. Although the cost of such glass addition is significantly less than the cost of borate addition. an additional slag treatment process is required to dissolve such a large quantity of glass into the slag pockets used industrially.The additional heat required to dissolve the glass could be generated, for example, by injecting oxygen into the slag. If the slag contains FeO, the injected oxygen could react exothermically with this iron oxide to produce Fe 2 O 3. This additional treatment involves time and cost. additional costs and requires the presence of a sufficient amount of FeO in the slag. The amount of glass required can not be added to the steel furnace since slags of low basicity cause rapid refractory degradation and, in steelmaking, low levels of chromium. The present inventors have carried out experiments in which a relatively large quantity of glass waste was first applied to a slag pocket before the liquid steel slags were poured into it. Although the heat of the liquid slag was high enough to melt the glass, the question of how to mix the glass homogeneously and without excessive heat loss was a problem. With large quantities of glasses, only a part of the glass waste has melted. A disadvantage of incomplete melting of the glass is that glass inclusions can form in the solid slag which, when used as a construction material, can cause a deleterious swelling reaction resulting from so-called alkali-granulate reactions. .
    The third way to reduce or avoid the formation of dicalcium silicate-γ consists of a rapid cooling of the steel slag. As indicated in the aforementioned article by Y. Pontikes et al., However, the cooling rate required to avoid the formation of dicalcium silicate-γ is very high. This cooling rate should be around 5 ° C / s. A disadvantage of such a rapid cooling process is that the required cooling rate can not be achieved in a slag yard where the slag pockets are emptied and the steel slags are solidified. air cooling, even when this air cooling is assisted by water spraying on the solidified slag. Very rapid cooling can be achieved only by an air or water granulation technique in which the liquid slag is solidified and cooled in an air or water jet. Because of this rapid cooling, a large part of the solidified steel slag is moreover amorphous (vitreous), which is not desirable when using steel slag as granulate in concrete constructions or constructions. road. In fact, the amorphous phases bind less strongly to the cement and therefore reduce the accelerated polishing coefficient (CPA) of the granulate (determined for example according to BS EN 1097 part 8) which is an important parameter when it is used in road constructions. Indeed, in the construction of a road, the surface layer must keep its roughness as long as possible in order to provide skid resistance for the traffic. The higher the accelerated polishing coefficient, the longer the aggregate will remain rough when used for road surfacing. A final disadvantage of water or air granulation techniques is that very fine granulate is produced, which is of less value than coarser aggregates.
    Tests in which steel slag is solidified by means of a water granulation technique are disclosed for example in the article "Treatments of AOD Slag to Enhance Recycling and Resource Conservation" by Q. Yang in Proceedings of Securing the Future, International Conference on Mining and the Environment, Metals and Energy Recovery, 27 June - 1 July 2005, Skelleftea, Sweden Slow cooling at an average rate of about 60 ° C / min from 1550 ° C to 623 ° C, resulted in a low glass content (3%) but many fines (90% less than 100 μm), while rapid cooling by granulation with water, in less than one minute, resulted in a high glass content of about 24% and a particle size between about 0.2 and about 3 mm.
    Water granulation tests, in which the steel slag is solidified in one minute, are also described in the article Dissolution Behavior of Fluorine in AOD Slag from the Production of Stainless Steel after Treatment for Volume Stabilization "by Q Yang et al. A. 2012 Scanmet IV: International Conference on Process Development in Iron and Steelmaking. Luleâ: MEFOS, Vol. 2, p. 517-526. By water granulation, the presence of dicalcium-γ silicate could be avoided, while slower cooling of the slag in about 5 hours from 1600 ° C to room temperature (i.e. average cooling of about 5 ° C / min), γ-dicalcium silicate was further formed.
    Tests in which slags are solidified by means of a water granulation technique are disclosed, for example, in the article "Stabilization Studies of EAF Slag for Its Use in Materials in Construction" by Q. Yang et al. in Proceedings, Asiasteel 24 Sep 2012, The Chinese Society for Metals, 6 p. In the air granulation test in which the steel slag was cooled in a stream of air in about one minute, the slag was stabilized so that no fines were produced. In the slow cooling test in which the slag was again cooled in 5 hours from 1600 ° C, that is to say at an average cooling rate of about 5 ° C / min, the slag have disintegrated into fines.
    An object of the present invention is to provide a new process for solidifying liquid steel slag which allows the reduction of fines, or in other words the formation of dicalcium silicate-γ, by a cooling process which does not require a rapid cooling, that is to say a cooling rate of at least 5 ° C / min, and which, in particular, does not require a step of granulation in air or water so that the formation of relatively large amounts of amorphous / vitreous phases can be avoided. To this end, the method according to the present invention is characterized in that - said tank has a bottom delimited by side walls, which bottom has an area of S m2; said successive layers of liquid steel slag are poured onto each other in said tank, with said intermediate layers having a volume of at least S x 0.03 m3 and; - said water cooling step is started after pouring said upper layer of liquid steel slag into the tank; and the temperature of each of said intermediate layers, determined as a volume-weighted average of the intermediate layer concerned, is maintained at least until the start of said water cooling step, for at least one hour, preferably during at least two hours, between 1300 ° C and a minimum temperature that is equal to or greater than said first temperature, i.e. equal to or greater than the temperature at which the dicalcium silicate-β is formed when cooling slowly liquid steel slag.
    In the process of the present invention, the steel slag is cooled with water which is applied to the top of the top layer. Due to the large volume of solidified steel slag layers and their relatively low thermal conductivity, the rapid cooling rate of at least 5 ° C / min required to prevent the transition of dicalcium silicate-β to dicalcium silicate-γ can not be achieved by applying water over solidified layers of steel slag. In fact, it takes hours or even days to cool a large volume of steel slag. According to the invention, it has nevertheless been found that, even without rapid cooling of the liquid steel slag, in particular without granulation in air or water of the liquid steel slag, the formation of dicalcium silicate- γ can still be considerably reduced by keeping the steel slag for a sufficiently long period of time at a relatively high temperature, particularly at a temperature which is higher than the temperature at which the β-dicalcium silicate is formed.
    The process of the present invention thus comprises two cooling phases, namely a first cooling stage in which the liquid steel slag is allowed to solidify and is maintained for a period of time at a relatively high temperature of between about 1300.degree. ° C and the temperature from which β-dicalcium silicate is formed, and a second subsequent cooling phase in which steel slag is further cooled with water, in particular at least until the temperature of each of the solidified slag intermediate layers is less than 400 ° C, preferably less than 300 ° C and more preferably less than 200 ° C. During this second cooling phase, the intermediate slag layers are cooled relatively rapidly to a temperature which is lower than the temperature at which the transition from ß to polymorph-γ of the dicalcium silicate takes place (which occurs in pure dicalcium silicate at a temperature of about 490 ° C).
    The first cooling phase is intended to allow the formation of crystalline phases different from the dicalcium silicate phases. These crystalline phases include in particular calcium silicate and magnesium (CMS) such as merwinite (C3MS2), bredigite (C7MS4) and diopside (CMS2). They are formed by crystallization of the liquid phases contained in the steel slag and also by transformation of the dicalcium silicate phases which are formed at higher temperatures, in particular from dicalcium silicate-α and / or α 'phases. It has been found that during the second subsequent cooling step, much less dicalcium silicates are formed, which can be explained by the fact that β-dicalcium silicate is formed less easily / rapidly from calcium silicate phases and of magnesium only from dicalcium silicate-α or α 'phases.
    In a preferred embodiment of the method according to the invention, the minimum temperature above which the temperature of each of the intermediate layers is maintained at least until the start of the water cooling step is equal to or greater than 700. ° C, preferably equal to or greater than 750 ° C, more preferably equal to or greater than 800 ° C, most preferably equal to or greater than 850 ° C and even more preferably equal to or greater than 900 ° C.
    These temperatures are all higher than the temperature at which the dicalcium silicate-β is formed. In pure dicalcium silicate, the transition from α-dicalcium silicate to β-dicalcium silicate actually occurs at 675 ° C. A higher temperature is however preferred, particularly when bredigite is formed in the steel slag. Bredigite (C7MS4) is actually a metastable phase that is stable only at higher temperatures. At lower temperatures, it can be transformed back into dicalcium silicate phases. By keeping the temperature higher, there is therefore more bredigite, if it is formed, in the slag.
    In another preferred embodiment of the process according to the invention, the temperature from which the β-dicalcium silicate is formed in the steel slag when cooling the liquid steel slag at room temperature is lowered by adding a phosphorus-containing compound with liquid slag, in particular a phosphate-containing compound and / or a pyrophosphate-containing compound.
    It has been found by adding a phosphorus-containing compound to liquid steel slag that not only is the transition from dicalcium silicate-β to dicalcium silicate-γ reduced but the temperature from which the dicalcium silicate-β is formed is lowered . In the process according to the present invention, the temperature of the different layers can thus be maintained more easily high enough to avoid the formation of dicalcium silicate during the first cooling phase.
    In yet another preferred embodiment of the process according to the invention, the basicity of the liquid steel slag, defined as the ratio between their calcium content, expressed as% by weight of CaO, and their silicon content, expressed as % by weight of SiO2, is decreased by adding glassy material after the liquid steel slag has been separated from the liquid steel, which vitreous material has another basicity, defined as the ratio between its calcium content, expressed as% by weight of CaO, and its silicon content, expressed as% by weight of SiO 2, which is less than 0.20, and preferably less than 0.15. The vitreous material preferably comprises at least 50% by weight, more preferably at least 60% by weight of silicon expressed as SiO 2. The vitreous material preferably comprises glass which has preferably been ground, in particular soda-lime silicate glass. The addition of vitreous material has the first effect of reducing the basicity of the steel slag so that less dicalcium silicate is formed therein during their cooling. However, the vitreous material is preferably applied in relatively small amounts which can be dissolved more homogeneously in the liquid slag but which are not sufficient to completely prevent the formation of dicalcium silicates. The addition of glassy material has the other effect of forming less bredigite and more merwinite in the liquid slag during their cooling. Unlike bredigite, merwinite has the advantage of being a stable phase. Therefore, even when the temperature of the steel slag is somewhat lower during the first cooling phase, the merwinite remains as it is in the steel slag and therefore can not increase the formation of dicalcium silicate phases below. a certain temperature at which the bredigite would no longer be stable. Other features and advantages of the invention will become apparent from the following description of some particular embodiments of the method according to the present invention. The reference numbers used in this description refer to the accompanying drawings in which:
    Figure 1 schematically illustrates the tank filled with successive layers of liquid steel slag;
    Figure 2 shows the phase formations in AOD slag computed with the Slag-A slag model with manual addition of bredigite;
    Fig. 3 is a graph showing the resulting temperature of a mixture of steel slag at a temperature of 1600 ° C and different amounts of glass at a temperature of 25 ° C;
    Figure 4 shows the phases present in the steel slag during the addition of different amounts of glass, at a temperature of 25 ° C, to the liquid steel slag at a temperature of 1600 ° C.
    Figure 5 shows the phase formations in the same AOD slag as in Figure 2, recalculated with the Slag-A model with manual addition of bredigite, but with the addition of 5% glass to the liquid steel slag;
    Figure 6 is a graph showing the relationship between the amount of calcium and magnesium silicates and the amount of dicalcium silicates in the various layers of solidified steel slag from Experiment 3;
    Figure 7 is a graph showing the amounts of calcium and magnesium silicates and the amounts of dicalcium silicates in the various solidified steel slag layers of Experiment 3 as a function of the calculated average temperature of each of the slag layers. of steel just before a next layer is applied over it;
    Fig. 8 is a graph showing the relationship between the amount of dicalcium silicates in the various solidified steel slag layers of Experiment 3 as a function of the average temperature of each of the layers of steel slag just before a next layer is applied over it; and
    FIG. 9 shows the evolution of the temperature measured at a place in the lower layer and in the first intermediate layer of experiment 3 as a function of time.
    The present invention relates to a process for solidifying liquid steel slag to produce solid steel slag. Solid steel slags are slags of calcium silicate that may contain different crystalline phases such as dicalcium silicate phases, calcium silicate and magnesium phases and other phases. The steel slags are especially stainless steel slags. It may be in particular slag AOD (Argon Oxygen Decarburization - oxygen and argon decarburization), VOD (Vacuum Oxygen Decarburization - Oxygen Decarburization with Oxygen) and EAF (Electric Arc Furnace - Arc furnace electric) or a combination thereof. When the steel slag consists of steel slag materials of different origins, they should not be mixed but they can be applied separately one above the other as described in more detail below.
    In order to be able to value the resulting solid steel slag as far as possible, they should contain a minimum amount of fines, in particular a minimum amount of particles smaller than 0.5 mm. These fines are mainly the result of slag disintegration which is due to the irreversible transformation of the C2S-β phase into C2S-Y causing a volume expansion of about 12%. During this phase transformation, internal stresses thus occur in the slag which results in the slag becoming disintegrated into fine particles. The coarser part of the solid steel slag can be used, after crushing and screening, as fine or coarse aggregate, especially in concrete and asphalt. Dicalcium silicate phases are formed in the steel slag when the steel slag has a basicity, defined as the ratio between their calcium content, expressed as% by weight of CaO, and their silicon content, expressed as% by weight of SiO2, which is greater than 1.2 so that the present invention is intended to solidify this solid slag material while reducing or preventing the formation of fines having, in particular, a size less than 0.5 mm .
    According to the present invention, the amount of fines is reduced by a particular cooling process. In practice, the liquid slags which are separated from the liquid steel, in particular liquid stainless steel, are applied in a slag pocket 1 and are transported in this slag pocket 1 to a slag yard. . When the liquid slags are applied into the slag pocket they have a temperature which is usually above 1500 ° C, for example in the range of 1550 ° C to 1750 ° C. Before being transported to the slag park, and during the actual transport, the liquid slag cools in the slag pocket, depending on the residence time in the slag pocket.
    As illustrated in FIG. 1, the liquid slag 2 is poured into successive layers in a reservoir 3. This reservoir 3 has a bottom 4 delimited by lateral walls 5. The successive layers comprise at least one lower layer 6, an upper layer 7 and at least two intermediate layers 8. The lower layer 6 is normally the layer which is applied to the bottom 4 of the reservoir 3 but it can also be one of the layers situated higher, in particular when the bottom 4 of the reservoir is too cold. and / or when the layer applied on this bottom 4 is too thin to guarantee the minimum temperature of the layer applied above it. It is therefore possible for two or even more than two lower layers 6 to be applied first in the tank 3.
    Each of the successive layers is usually applied by pouring a slag pocket 1 into the tank. However, it is also possible to pour two or more slag pockets 1 at the same time, or shortly after one another (so that the steel slags of the first slag pocket are not yet solidified, for example at an interval of less than 5 minutes), in the tank so that the liquid slags of these slag pockets 1 melt into each other and form a layer of liquid steel slag 2 in the tank 3. After having poured the upper layer 7 into the tank 3, water is applied, in particular sprayed, onto the steel slag in the tank 3 to cool the layers of solidified steel slag 6-8. This water cooling step is started at least one hour, preferably at least two hours or more, preferably at least three hours after pouring the upper layer 7 of liquid steel slag 2 into the tank 3. In this way the intermediate layers 8, which are intended to produce solid steel slags with fewer fines, are maintained for a longer time at a higher temperature before being cooled with water. The water cooling step is preferably started less than ten hours, preferably less than seven hours and more preferably less than five hours after pouring the upper layer 7 of liquid steel slag into the tank 3. In this way the intermediate layers 8 can not cool to a low temperature before being cooled more rapidly with water.
    An important feature of the present invention is that the temperature of each of the intermediate layers 8 should be maintained at least until the start of the water cooling step, i.e. the water is applied to the top layer for at least one hour and preferably for at least two hours, at 1300 ° C and a minimum temperature which is equal to or greater than the temperature from which dicalcium silicate-β is formed in steel slag when the liquid steel slag is cooled to room temperature, particularly at a cooling rate of about 10 ° C / min. This temperature can be determined by means of a DTA (Differential Thermal Analysis) analysis in which the steel slags are cooled, for example, at a rate of about 10 ° C / min. The temperature of each of the intermediate layers 8 is defined here as a weighted average by volume of the intermediate layer concerned. If 1/3 of the layer has a temperature of 700 ° C, 1/3 a temperature of 720 ° C and 1/3 a temperature of 750 ° C, then the temperature of the layer is equal to 1 / 3x700 ° C + 1 / 3x720 ° C + 1 / 3x750 ° C = 723 ° C.
    The minimum temperature is preferably 700 ° C or higher, more preferably equal to or greater than 750 ° C, most preferably 800 ° C or higher, and even more preferably greater than or equal to 850 ° C or even greater than or equal to 900 ° C. The temperature of each of said intermediate layers 8 (determined as a weighted average per volume of the intermediate layer 8 concerned) is preferably maintained before the start of said water cooling step, for at least one hour, preferably for at least one hour. two hours, below 1200 ° C, and preferably below 1100 ° C.
    During this first cooling phase, at these relatively high temperatures, different crystalline phases of the dicalcium silicates are formed. The steel slag usually comprises not only the calcium, silicon and oxygen elements but also magnesium (in an amount which is preferably greater than 4% by weight, more preferably greater than 6% by weight and ideally greater than 8% by weight. weight). The presence of magnesium causes the formation of calcium and magnesium silicates, particularly merwinite and / or bredigite, during the first cooling phase at these relatively high temperatures rather than dicalcium silicates, more particularly rather than α-dicalcium silicates. . The dicalcium silicates (α or α ') which have been formed at higher temperatures are converted during this first cooling stage into other crystalline phases, in particular into the calcium silicate and magnesium phase. During the subsequent water-cooling phase, these crystalline phases, which are different from the dicalcium silicate, are less easily converted to β-dicalcium silicate and then to dicalcium-γ-silicate, so that by increasing the amount of these crystalline phases, it is possible to considerably reduce the disintegration of steel slag.
    The successive layers 6-8 of liquid steel slag 2 are poured at predetermined temperatures and at predetermined time intervals onto each other in said reservoir 3. The temperature of each of these intermediate layers 8 can be maintained at above the minimum temperature described above by maintaining said predetermined temperatures sufficiently high and said predetermined time intervals sufficiently short. The predetermined time intervals are in particular less than 90 minutes, preferably less than 75 minutes, more preferably less than 60 minutes and ideally less than 50 minutes. The predetermined temperatures of the liquid steel slag 2 at the moment when they are poured into said successive layers are in particular greater than 800 ° C., preferably greater than 900 ° C. and better still greater than 950 ° C. or even greater than 1000 ° C. In order to allow the various layers of liquid steel slag to solidify to a certain extent before the next layer is poured over, the predetermined intervals between the different pouring steps are preferably greater than 5 minutes, better still higher at 10 minutes and ideally above 15 minutes.
    The intermediate layers 8 should furthermore have a sufficiently large average thickness to prevent too rapid cooling of the steel slag in the layer concerned (before the next layer is applied over it) and to allow the production of a sufficiently coarse aggregate by crushing the solidified steel slag in each intermediate layer 8. When the bottom 4 of the tank 3 has an area of S m 2, the intermediate layers 8 should each have a volume of at least S x 0.03 m 3 so that the layers intermediates 8 have an average thickness of at least 0.03 m. The volume of intermediate layers 8 is preferably at least S x 0.04 m3 and more preferably at least S x 0.05 m3.
    The intermediate layers 8 are preferably not too thick so that the steel slags are of a more uniform temperature in each layer. In this way, it is possible to prevent too hot areas in which α-dicalcium silicate could be formed instead of calcium and magnesium silicates during the first cooling phase and / or too cold areas in which silicate dicalcium-ß in particular could already be formed. The volume of intermediate layers of liquid steel slag is preferably at most S x 0.5 m3, more preferably at most S x 0.4 m3, ideally at most S x 0.3 m3 and even better still at most S x 0.2 m3.
    The temperature of each of the intermediate layers 8, determined as a volume-weighted average of the intermediate layer concerned, preferably falls to an average level which is not greater than 50 ° C./min, preferably not more than 40 ° C. min / min, more preferably not more than 30 ° C / min and ideally not more than 20 ° C / min from the application of liquid steel slag until the layer is covered by another intermediate layer 8 or by said upper layer 7. This slow rate of cooling can be obtained by allowing the intermediate layer to cool by cooling in air, that is to say by being in contact with the atmosphere. It is advantageous to avoid high cooling rates in view of the fact that with these relatively low cooling rates, the solidified steel slags produced contain a smaller amount of amorphous phases (compared to existing processes in which Steel slags poured into the slag park are immediately cooled by water spraying to effect rapid cooling, limiting the transition of dicalcium silicate-ß to dicalcium silicate-γ, the cooling rate preferably being so low as The solid steel products produced contain less than 10% by weight, preferably less than 7% by weight and more preferably less than 5% by weight of amorphous phases, an advantage of such small amounts of amorphous phases is that the aggregates produced at steel slags have a high CPA value.While it is less preferable, a small amount of water could be sprayed over the successive layers 6-8 to accelerate the cooling / solidification of the steel slag before a subsequent layer is applied over it, but this amount should not be too great to prevent too rapid cooling of the slags. steel slag and to help maintain the temperature of the intermediate layers above the minimum temperature described above until the effective cooling stage with water. In this regard, the tank is preferably protected against rain.
    During the water cooling step, water is applied to the upper layer 7 of steel slag. This water is preferably applied at least until the temperature of each of the intermediate layers 8 (i.e. their weighted average temperature) is less than 400 ° C, preferably less than 300 ° C. and more preferably below 200 ° C. The application of water to the upper layer 7 of steel slag is preferably stopped when the temperature of this upper layer 7 of steel slag is still greater than 100 ° C. In this way, all the applied water evaporates resulting in a dry steel slag material. The cooling water is preferably sprayed onto the upper layer 7 of steel slag and is preferably applied at a rate such that there is no accumulation of water on the top layer 7 of slag. steel, that is, the rate at which water is applied is equal to or less than the rate at which water evaporates. It has been found that the most efficient cooling of the layers 6-8 of steel slag can be achieved in this way.
    The successive layers 6-8 of steel slag preferably have a total height of less than 2.0 m, preferably less than 1.8 m, more preferably less than 1.6 m and ideally less than 1 m , 4 m. In this way, sufficiently rapid cooling of all these layers can be achieved by applying water to the top of the top layer 7.
    The liquid steel slag 2 has a predetermined basicity, defined as the ratio between their calcium content, expressed as% by weight of CaO, and their silicon content, expressed as% by weight of SiO 2. This basicity is particularly so high that, during a slow cooling of steel slag, there is formation of dicalcic silicates leading to a (partial) disintegration of steel slag, that is to say what it is called an effusement or a spraying of steel slag. The basicity is more particularly generally greater than 1.2, in particular greater than 1.4 and often greater than 1.6. The basicity of the EAF slags is generally lower than the basicity of the AOD and VOD slags. The EAF slags can have, for example, a basicity of about 1.4, while the AOD slags have, for example, a basicity of 1.7 or even more, so that the AOD slags are more prone to Efficially that EAF slag.
    In the process of the present invention, the basicity of the liquid steel slag is preferably lowered by adding thereto a vitreous material after the liquid steel slag has been separated from the liquid steel. This vitreous material has a basicity, defined as the ratio between its calcium content, expressed as% by weight of CaO, and its silicon content, expressed as% by weight of SiO 2, which is less than 0.20, and preferably less than 0.15. The vitreous material preferably comprises at least 50% by weight, more preferably at least 60% by weight of silicon expressed as SiO 2 and especially comprising glass, preferably glass waste, which has preferably been ground. The glass may in particular be soda-lime silicate glass. This type of glass is available as waste material and is known as cullet (glass debris). The vitreous material preferably comprises magnesium, especially in an amount of at least 1.0, preferably at least 2.0% by weight. An advantage of the additional magnesium is that it can contribute to the formation of calcium silicate and magnesium phases. In addition, in the case where the steel slag comprises chromium, for example stainless steel slag, there may be formation of a magnesiochromite spinel phase which reduces the leaching of chromium from the slag. steel.
    The vitreous material may be added and mixed with the liquid slag when the liquid slag is poured into the slag pocket 1. It is however easier to apply the vitreous material separately to the slag pocket, in particular by applying it in the slag pocket. slag pocket before introducing (pouring in) liquid steel slag. Tests have shown that when 3% by weight of cullet is introduced into the slag pocket before pouring the liquid steel slag (having a temperature above 1500 ° C), more than 99% of the cullet dissolves in liquid steel slag. More cullet could be dissolved in the liquid steel slag by injecting the cullet into the steel slag which is poured into the slag pocket. When, for example, 5% by weight of cullet is injected into the liquid steel stream, all the cullet dissolves therein. Calculations have shown that when, for example, 15% by weight of cullet (having a temperature of 25 ° C.) is added to the liquid acidic slags, their temperature only drops by a little more than 200 ° C. that liquid steel slags contain enough heat to dissolve very large quantities of cullet.
    The vitreous material, however, is added to the liquid steel slag in an amount which is preferably less than 10 parts by weight, preferably less than 9 parts by weight, and more preferably less than 8 parts by weight, per 100 parts by weight. liquid steel slag. The smaller the amount of glassy material, the easier it can be dissolved evenly in the liquid steel slag.
    An advantage of adding a glassy material to the liquid steel slag is that the basicity of the liquid steel slag is reduced. More importantly, however, the addition of a vitreous material, in combination with the solidification process of the present invention described above, has additional synergistic effects. Indeed, the addition of glass reduces the formation of bredigite during the first cooling phase and increases the formation of merwinite. This effect can already be demonstrated in the presence of relatively small amounts of vitreous material. Reducing the amount of bredigite in favor of the formation of other phases of calcium silicate and magnesium has the great advantage that, unlike these other phases, the bredigite is metastable and can therefore lead to the formation of dicalcium silicate during cooling of the steel slag, especially during the water cooling phase. Because of the large volume of solidified steel slag contained in the different layers, rapid cooling thereof (by quenching with water or air) is indeed not possible.
    Calculations for slag mineralogy and glass additions
    The effects described above of the solidification process of the present invention and also the special effects of adding glass in combination with this solidification process can be explained on the basis of the following calculations. These calculations are performed for average AOD slags having the following composition:
    Table 1: Average composition (in% by weight) of the AOD slag used in the calculations of the Slag-A model of FactSage
    The calculations were performed on the equilibrium mineralogy that can be expected at different temperatures with the FactSage Slag-A model with manual addition of bredigite (Ca7MgSi4O16 or C7MS4), with a stability range of about 900-1300 ° C. Concerning the behavior of C2S, the model could only predict the transition to γ from α 'directly. C2S-ß was not considered a stable phase since it is formed only because it is easier to nucleate than C2S-Y. In practice, a transition of C2S-α 'to C2S-β occurs, and further a transformation of C2S-β to C2S-Y (destructive and avoidable) occurs if it is not blocked by boron (and / or quenching).
    Figure 2 shows the formation of phases in the AOD slag during their slow cooling so that the different phases are in equilibrium at different temperatures for which equilibrium calculations have been made. Linear lines were drawn between these calculated data. Equilibrium states have been calculated for only a limited number of temperatures, especially for 2000; 1900 1800; 1700; 1600; 1500; 1400; 1300; 1200; 1100; 500 and 400 ° C. Therefore, these graphs do not show exactly from what temperature the different crystalline phases are formed, in particular do not show the temperature from which C2S-ß is formed, since there is no calculation in the range between 1100 and 500 ° C.
    The following phases were indicated in FIG. 2: LIQ: liquid phase a-C2S: dicalcium silicate-α = α-Ca 2 SiO 4 α-C2S: dicalcium silicate-α 'α-Ca 2 SiO 4 MeO: magnesium oxide SPINA: spinel = Me2 + Me3 + 2O4 C7MS4: bredigite = Ca7MgSi4O16 CaF2 C5T4: Ca5Ti4O13 C3T2: Ca3Ti2O7 C3MS2: merwinite = Ca3MgSi2O8 ß + Y-C2S: beta-dicalcium silicate and gamma C3MA4: Ca3MgAl4O10
    In Figure 2, it can be seen that α-C2S begins to be formed only at elevated temperatures. In a next phase, the main phase that is formed is the bredigite. At 1100 ° C, this bredigite forms about 70% of the slag. During the slow cooling down, the bredigite is converted mainly into merwinite and dicalcium silicate (β-C2S which then turns into Y-C2S: not shown in Figure 2). It therefore appears from Fig. 2 that, when the slag is cooled slowly during the first cooling stage of the process of the present invention, the α-C2S which is already present in the steel slags at high temperatures (occurring in the slag pocket) may disappear and the bredigite may form. If a-C2S could not disappear due to the fact that the slag would not be cooled sufficiently slowly during the first cooling phase, it would subsequently be converted more easily than the bredigite, and in particular the merwinite, into dicalcium silicate beta and gamma.
    Another calculation was made with the same model but with the addition of glass. The glass had the following composition:
    Table 2: Composition of the glass (in% by weight) added to the AOD slag used in the calculations of the Slag-A model of FactSage
    Since potassium is not well modeled in the FactSage databases, the K2O content has been added to the Na2O content.
    When adding glass at 25 ° C to the slag at 1600 ° C, the slag temperature dropped dramatically as shown in Figure 3. This is the result of an adiabatic calculation of slag and glass that assumes that there are no losses to the environment or to stirring gas, etc. When 15% glass is added, the temperature drops by more than 200 ° C.
    Figure 4 shows the phases present in the slag at the time of addition of glass (% on the X axis) to the temperature resulting from the mixing of slag with the amount of glass added. Figure 4 shows that the liquid fraction does not decrease because of the low melting point of the glass and the disappearance of the C2S phase (high melting). When 15% glass is added, the liquid fraction should increase by 60 to 80%. When more glass is added, the liquid fraction decreases again due to merwinite formation.
    Figure 5 shows the phases in the slag as a function of temperature for an addition of 5% by weight of glass. The different equilibrium states were calculated at temperatures of 1600; 1500; 1400; 1300; 1200; 1100; 1000; 900; 800; 700; 600; 500; 200 and 100 ° C.
    The following phases were indicated in FIG. 5: LIQ: liquid phase a-C2S: dicalcium silicate-α = a-Ca2SiO4 C7MS4: bredigite = Ca7MgSi4Oi6 CaF2 CT: CaTiO3 C2A2S: Ca2Al2SiO7 C3MS2: merwinite = Ca3MgSi2O8 N2C2S3: Na2Ca2Si3O9 C4S2F2: cuspidine = Ca4Si2F2O7 ß + Y-C2S: beta and gamma dicalcium silicate
    When comparing Figure 5 to Figure 2, it can be seen that at temperatures above 800 ° C, the amount of bredigite is considerably reduced (at 1100 ° C from about 70% to about 24%), while the amount of merwinite is considerably increased (at 1100 ° C from about 3% to about 47%). The slow, high temperature cooling process of the present invention thus allows, in combination with the addition of glass, to form more stable merwinite than metastable bredigite. After addition of 5% by weight of glass, the nucleation of merwinite already begins at a temperature between 1400 and 1500 ° C, while without the addition of glass, the nucleation of merwinite begins at a lower temperature, that is to say at a temperature between 1200 and 1300 ° C. As can be seen from Figure 5, bredigite is converted mainly during another slow cooling process into dicalcium silicates. In addition, the addition of glass causes a reduction in the amount of dicalcium silicate at lower temperatures, but this reduction (from about 40% to about 24%) is considerably less than the effect of adding glass. on the quantities of bredigite and merwinite. The process of the present invention thus makes it possible to considerably improve the effect of the addition of glass and in particular makes it possible to obtain a considerable effect on the formation of fines with only a limited quantity of glass.
    To further reduce the formation of fines, the usual borates can be added to the liquid slag. These borates reduce the transition from dicalcium silicate-β to dicalcium silicate-γ. An additional advantage of adding borates is that they lower the temperature of C2S-α 'phase transformation to C2S-β. In pure dicalcium silicate, C2S-α 'converts to C2S-β at a temperature of 675 ° C. Differential thermal analysis (DTA) was performed on dicalcium silicate doped with 0.13% by weight of disodium tetraborate (Na2B4O7). The transition from the α 'phase to the β phase occurred at an average temperature of 638 ° C, that is to say at a temperature which is about 37 ° C lower than the temperature at which this phase transition occurs without the addition of borate.
    The same effect can be obtained by the addition of a phosphorus-containing compound. DTA analysis was also performed on dicalcium silicate doped with 2% by weight of a composition consisting of about 50% CaF2 and about 50% {(Ca5 (PO4) 3OH) + (Ca5 (PO4) 3F)}. The transition from the α 'phase to the β phase occurred at an average temperature of 641 ° C, that is to say at a temperature which is about 34 ° C lower than the temperature at which this phase transition occurs without the addition of the phosphorus-containing compound. In contrast to borates, such phosphorus-containing compounds, particularly phosphate- and / or pyrophosphate-containing compounds, have no toxic effect and can therefore be freely added to the liquid steel slag. The phosphorus-containing compound not only reduces the conversion of C2S-β to C2S-Y but also lowers the temperature from which C2S-β is formed when cooling the liquid steel slag. In this way, it is therefore easier in the method of the present invention to maintain the steel slag layers during the first cooling phase at a temperature which is higher than the temperature at which C2S-β begins to be formed. in steel slag. Results of experimental tests
    Experience 1
    In this experiment, slag pockets in which liquid AOD slags at a temperature below 1000 ° C were allowed to cool were poured into a tank without rapid cooling by water. This experience resulted in a quantity of fines of over 80%. When the slag pockets were poured into the tank while the steel slag still had a temperature of at least 1000 ° C, and then the stack of layers was cooled by spraying water on them. Here, solidified steel slag was obtained which contained almost no fines.
    Experience 2
    The same experiment was carried out with the same AOD slag with a combination of hot (> 1000 ° C) and cold (<1000 ° C) slag pockets. In one test, the amount of hot pockets was 55% and the amount of cold pockets was 45%. This test gave 20% of fines. A combination of 2% warm pockets and 98% cold pockets resulted in about 80% fines.
    Experiment 3 22 slag pockets with varying amounts of liquid steel slag (AOD and EAF) were poured at different temperatures (mainly due to different residence times in the slag pockets) and at different time intervals in a slag tank with a bottom area of 6 x 20 m2. The total height of the stack of layers was about 1.4 m. 4.5 hours after pouring the top layer into the tank, water was sprayed over it. The surface temperature of each of the layers was measured just before pouring the next layer over and the temperature was also measured in the lower layer and in the first intermediate layer, i.e. in the applied layer. above the lower layer. The average temperature of each layer just before a subsequent layer was applied over it was calculated using a temperature model. The content of dicalcium silicate (C2S) and the content of calcium and magnesium silicate (CMS) (sum of merwinite, bredigite and diopside) of the different layers was measured after solidification and cooling of the layers. The different results are shown in the following table.
    Table 2: Average temperature and content of C2S and CMS of the different layers.
    Fig. 6 is a graph with a linear trend line illustrating the relationship between the C2S and CMS content of the different layers. It can be seen that there is a linear relationship between these two levels. Since in the solidification process of the present invention, CMS formation is increased by keeping the steel slag for a sufficient period of time at a higher temperature before starting the water cooling process, the content of C2S, and thus the formation of fines, should be reduced accordingly.
    Fig. 7 is a graph illustrating the relationship between the C2S content and the CMS content as a function of the average temperature of the different layers just before the next pour, i.e. just before applying the next layer. It can be seen that, in general, the formation of C2S is stopped when the average temperature of the layer is higher just before the next layer is applied thereto. This effect is more pronounced for AOD slag. EAF slags are less sensitive to effusability at lower temperatures because of their lower basicity.
    Fig. 8 is a graph with an exponential line illustrating the relationship, for the different AOD slag layers, between the average temperature of the layer just before the next pour and the C2S content. It can be seen that the higher the temperature, the lower the C2S content.
    Figure 9 is a graph showing the temperatures measured during the first 11 hours by the thermal probes in the lower layer and in the layer applied just above it (positioned at a height of 0.07 and 0.27 m from the bottom). It can be seen that, despite the large volume of the first layer of liquid steel slag, the temperature decreased to a lower level, i.e. at a temperature of about 900 ° C after 11 hours, while due to the insulation provided by this lower layer and the additional heat applied by the layers of liquid slag poured over it, the temperature of the second layer dropped very rapidly at the beginning of about 200 ° C (at about 1000 ° C), until the next layer of liquid slag is applied thereto, after which the temperature of the second layer remained nearly constant at a temperature of about 1050 ° C. At this temperature, bredigite and merwinite are the main crystalline phases that are formed. The method of the present invention allows this temperature to be maintained without having to apply heat to the slag layers until equilibrium is established, i.e. maximum of bredigite and in particular of merwinite be formed. During the next water cooling phase, the solidified slag layers are cooled more rapidly to prevent the formation of beta and gamma dicalcium silicates starting from the bredigite phases. The amount of these bredigite phases is preferably reduced by adding a vitreous compound such as ground glass waste to liquid slag.
    In this experiment, a quantity of borates was added to the AOD steel slag to avoid the transition from C2S-β to C2S-γ. Borate was not added to the EAF slag because of its low basicity, i.e., a basicity of about 1.4. The AOD slags had a basicity of about 1.8.
    权利要求:
    Claims (20)
    [1]
    A method for solidifying liquid steel slag (2) for producing solid steel slag, which liquid steel slag comprises at least the calcium, silicon and oxygen elements and has a basicity, defined as the ratio between their calcium content, expressed as% by weight of CaO, and their silicon content, expressed as% by weight of SiO 2, which is greater than 1.2 so that when the liquid steel slags are cooled to temperature D-dicalcium silicate is formed therein from a first temperature, which process comprises the steps of: pouring at least four successive layers (6-8) of said liquid steel slags (2) in a reservoir (3), which successive layers comprise a lower layer (6), an upper layer (7) and at least two intermediate layers (8); - leave the liquid steel slag (2) to solidify in the tank (3); and - cooling the solidified steel slag in the reservoir (3) by applying water to the solidified steel slag, characterized in that - said reservoir (3) has a bottom (4) delimited by side walls (5), which bottom (4) has an area of S m2; said successive layers (6-8) of liquid steel slag are poured onto each other in said reservoir (3), with said intermediate layers (8) having a volume of at least S × 0.03 m 3 and ; - said water cooling step is started after pouring said upper layer (7) of liquid steel slag into the tank (3); and the temperature of each of said intermediate layers (8), determined as a volume-weighted average of the intermediate layer (8) concerned, is maintained at least until the beginning of said water cooling step, for at least one hour, preferably for at least two hours, between 1300 ° C and a minimum temperature that is equal to or greater than said first temperature.
    [2]
    2. Method according to claim 1, characterized in that said minimum temperature is equal to or greater than 700 ° C, preferably equal to or greater than 750 ° C, more preferably equal to or greater than 800 ° C, ideally equal to or greater than 850 ° C and even more preferably equal to or greater than 900 ° C.
    [3]
    3. Method according to claim 1 or 2, characterized in that the temperature from which the β-dicalcium silicate is formed in the steel slag when cooling the liquid steel slag to room temperature is lowered. adding to the liquid slag a phosphorus-containing compound, in particular a phosphate-containing compound and / or a pyrophosphate-containing compound.
    [4]
    4. Method according to any one of claims 1 to 3, characterized in that the basicity of the liquid steel slag is reduced by adding thereto a vitreous material after the liquid steel slag has been separated from the liquid steel slag. liquid steel, which vitreous material has another basicity, defined as the ratio between its calcium content, expressed as% by weight of CaO, and its silicon content, expressed as% by weight of SiO 2, which is less than 0, And preferably less than 0.15.
    [5]
    5. Method according to claim 4, characterized in that said vitreous material comprises at least 50% by weight, preferably at least 60% by weight of silicon, expressed as SiO 2, said glassy material preferably comprising glass which preferably has has been milled, in particular soda-lime silicate glass.
    [6]
    6. Method according to claim 4 or 5, characterized in that the liquid steel slag and the vitreous material are both applied in the same slag pocket, said vitreous material being preferably applied in the slag pocket before apply the liquid steel slag into it.
    [7]
    7. Method according to any one of claims 4 to 6, characterized in that 100 parts by weight of liquid steel slag, less than 10 parts by weight, preferably less than 9 parts by weight and more preferably less than 8 parts by weight of said vitreous material are added to the liquid steel slag.
    [8]
    8. Method according to any one of claims 1 to 7, characterized in that the volume of said intermediate layers of liquid steel slag is at least S x 0.04 m3 and preferably at least S x 0.05 m3.
    [9]
    9. Method according to any one of claims 1 to 8, characterized in that the volume of said intermediate layers (8) of liquid steel slag is at most S x 0.5 m3, preferably at most S x 0, 4 m3, more preferably at most S x 0.3 m3 and ideally at most S x 0.2 m3.
    [10]
    10. Process according to any one of claims 1 to 9, characterized in that said water cooling step is started at least one hour, preferably at least two hours and better still at least three hours after pouring said top layer (7) liquid steel slag (2) in the tank (3).
    [11]
    11. Method according to any one of claims 1 to 10, characterized in that said water cooling step is started less than ten hours, preferably less than seven hours and even more preferably five hours after pouring said top layer ( 7) liquid steel slag (2) in the tank (3).
    [12]
    12. Method according to any one of claims 1 to 11, characterized in that said successive layers (6-8) have a total height of less than 2.0 m, preferably less than 1.8 m, better still less than 1.6 m and ideally less than 1.4 m.
    [13]
    Method according to any one of claims 1 to 12, characterized in that said successive layers (6-8) of liquid steel slag (2) are poured at predetermined temperatures and at predetermined time intervals. on the others in said tank (3), which time intervals are less than 90 minutes, preferably less than 75 minutes, more preferably less than 60 minutes and ideally less than 50 minutes.
    [14]
    A method according to any one of claims 1 to 13, characterized in that said successive layers (6-8) of liquid steel slag (2) are poured at predetermined temperatures and at predetermined time intervals. on each other in said reservoir (3), which time intervals are greater than 5 minutes, preferably greater than 10 minutes and more preferably greater than 15 minutes.
    [15]
    15. Method according to any one of claims 1 to 14, characterized in that the temperatures of liquid steel slag (2) at the moment when they are poured into said successive layers (6-8) are greater than 800 ° C preferably above 900 ° C and more preferably above 950 ° C.
    [16]
    16. A method according to any one of claims 1 to 15, characterized in that the temperature of each of said intermediate layers (8), determined as a volume-weighted average of the intermediate layer (8) concerned, decreases at an average rate. which is not more than 50 ° C / min, preferably not more than 40 ° C / min, more preferably not more than 30 ° C / min and ideally not greater than 20 ° C / min from its application until it is covered by another intermediate layer (8) or by said upper layer (7).
    [17]
    17. A method according to any one of claims 1 to 16, characterized in that the temperature of each of said intermediate layers (8), determined as a volume-weighted average of the intermediate layer (8) concerned, is maintained before starting of said water cooling step, for at least one hour, preferably for at least two hours, below 1200 ° C, and preferably below 1100 ° C.
    [18]
    18. Process according to any one of claims 1 to 17, characterized in that said successive layers (6-8) of liquid steel slag (2) are poured at predetermined temperatures and at predetermined time intervals. on the others in said reservoir (3) and the temperature of each of said intermediate layers (8), determined as a volume-weighted average of the intermediate layer (8) concerned, is maintained above said minimum temperature while maintaining said temperatures predetermined high enough and said predetermined time intervals sufficiently short.
    [19]
    19. A method according to any one of claims 1 to 18, characterized in that the solidified steel slag is cooled by applying water to the upper layer (7) of steel slag until the the temperature of each of said intermediate layers is less than 400 ° C, preferably less than 300 ° C and more preferably less than 200 ° C.
    [20]
    20. Process according to any one of claims 1 to 19, characterized in that the basicity of the liquid steel slag is greater than 1.4 and in particular greater than 1.6.
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR1330477A|1962-08-02|1963-06-21|Process for preparing a prefragmented blast furnace slag|
    GB1058143A|1964-02-21|1967-02-08|Fritz Forschepiepe|Method for the dressing of slag|CN109437609B|2018-12-19|2021-03-23|南京凯盛国际工程有限公司|Magnesium slag granulation method|
    BE1027914B1|2019-12-24|2021-07-26|Orbix Productions|PROCESS FOR THE PRODUCTION OF AN ALKALINE AGGREGATE|
    EP3901289A4|2020-04-24|2021-10-27|Orbix Solutions|Method for producing a mainly crystalline solidified steel slag|
    TWI729791B|2020-04-27|2021-06-01|中國鋼鐵股份有限公司|Method for improving slag liquidity|
    法律状态:
    2017-12-13| FG| Patent granted|Effective date: 20160623 |
    2017-12-13| HC| Change of name of the owners|Owner name: UNIVERSITE LIBRE DE BRUXELLES; BE Free format text: DETAILS ASSIGNMENT: CHANGE OF OWNER(S), CHANGEMENT NOM PROPRIETAIRE; FORMER OWNER NAME: UNIVERSITE LIBRE DE BRUXELLES Effective date: 20170904 |
    2019-12-05| MM| Lapsed because of non-payment of the annual fee|Effective date: 20190331 |
    优先权:
    申请号 | 申请日 | 专利标题
    EP2014056341|2014-03-28|
    EPPCT/EP2014/056341|2014-03-28|
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