EP0485309A1 - Product based on coated magnesium for the desulphurizing of cast iron or liquid steel - Google Patents
Product based on coated magnesium for the desulphurizing of cast iron or liquid steel Download PDFInfo
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- EP0485309A1 EP0485309A1 EP91420388A EP91420388A EP0485309A1 EP 0485309 A1 EP0485309 A1 EP 0485309A1 EP 91420388 A EP91420388 A EP 91420388A EP 91420388 A EP91420388 A EP 91420388A EP 0485309 A1 EP0485309 A1 EP 0485309A1
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- Prior art keywords
- product
- organic
- refractory
- powder
- magnesium
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
- C21C1/025—Agents used for dephosphorising or desulfurising
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
- B22F1/102—Metallic powder coated with organic material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/16—Metallic particles coated with a non-metal
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
- C21C7/0645—Agents used for dephosphorising or desulfurising
Definitions
- the invention relates to a product for desulfurization of cast irons or liquid steels, based on coated magnesium particles.
- magnesium powder is well known for the desulfurization of cast iron and steel.
- magnesium presents difficulties of use which we try to overcome by coating the particles of magnesium, the diameter of which is generally less than 2 mm, a layer of fine powder mineral product consisting of grains whose diameter is generally less than 150 microns.
- the adhesion can be carried out using organic binders which has certain advantages.
- application EP 292 205 describes a similar coating where the magnesium is first covered with a first layer of a hydrophobic product and then with a second layer of a particulate refractory product.
- hydrophobic products which are also organic products, are selected from aliphatic or aromatic liquid oils with a low viscosity at 25 ° C, or solid at room temperature but liquid at low temperatures (for example waxes or paraffin).
- the refractory mineral product used generally consists of metal oxides, mixtures or complexes of oxides (for example: MgO, Al2O3, SiO2, TiO2, vermicullite, ...), fluorides, carbon. .
- Desulfurizing products based on coated magnesium, obtained using these organic products have drawbacks, however.
- they are not completely impermeable to humidity, which gives off hydrogen in the event of contact with water (liquid or vapor); this release of hydrogen obviously presents a risk which must be avoided.
- a slight rise in temperature can cause softening of the organic matter and thus cause deterioration of the refractory coating of the magnesium grains; this results in a risk of sticking and agglomeration of the grains between them, causing difficulties and irregularities in processing during the introduction of the desulfurizing agent into the liquid metal.
- These harmful temperature rises generally occur during the storage of the products in exposed places, for example near ovens, radiation of the sun ...
- the invention is a product for desulfurization of cast irons or liquid steels based on magnesium grains coated with a product.
- organic and a refractory powder characterized in that the organic product is based on saturated aliphatic acids or their solid esters at ordinary temperature. Solid acids or esters are usually used at low temperature, preferably below 60 ° C or better of 80 ° C, the melting point not generally exceeding 110 ° C, with a clear melting, without going through a softening phase.
- esters usually used are the glycerine triesters or their mixtures, in particular the saturated triesters obtained by hydrogenation of castor oil, which essentially leads to glycerol trihydroxystearate.
- Hydrogenated sunflower oil, glycerol stristearate and sometimes stearic acid can also be used.
- the solid coating products of the invention make it possible, on the one hand, to make a coating of Mg which is stable at high temperature, without it being necessary to carry out chemical transformations of starting materials to obtain it. It may also be recalled that with this stable coating, an Mg powder can withstand severe temperature storage conditions (proximity of ovens, sun, etc.) without its flowability being deteriorated.
- the esters of the invention generally constitute most or preferably all of the organic product used for coating the magnesium.
- said organic product may contain other organic products than the esters of the invention, in particular unprocessed residues of the products used to obtain said esters.
- They are particularly suitable for coating magnesium on which they adhere remarkably thanks to their non-zero but low acidity which makes it possible to react very superficially with the Mg particles.
- hydrogenated castor oil has an acid number of 4 (which represents the weight of KOH in mg to neutralize 1 g of product) and melts at 86 ° C.
- any infusible metal oxides or other powdered refractories known from the prior art can be used, but also desulphurizing agents such as C2Ca, CO3Ca, CaO ... or other minerals such as carbons ... or their mixtures.
- the refractory product is sensitive to humidity, such as for example C2Ca
- the magnesium particles are usually less than 2 mm in size, preferably between 300 and 800 ⁇ m approximately and the refractory product powder has a grain size between 0 and 80 ⁇ m approximately.
- ester according to the invention 0.5 to 1.5 parts by weight of ester according to the invention are used (for example hydrogenated castor oil) per 5 parts by weight of refractory protection product, most often about 1 part of ester for 5 parts of protective slag.
- the proportion of coating product relative to the desulphurizing agent can range from 2% to 25% (weight).
- the magnesium desulfurizing product coated according to the invention can be mixed with other desulfurizing agents, in particular with calcium carbide, or with other mixtures based on calcium carbide (for example mixture of the carbonate type of calcium + calcium carbide + carbon), with or without lime. It can also be mixed with inert products.
- the magnesium particles and the ester according to the invention in the solid state are introduced simultaneously into a heated mixer so as to initially produce particles uniformly covered with ester; the refractory product powder is then introduced and particles coated with slag are then obtained which are removed from the mixer and then cooled.
- the invention makes it possible to obtain desulfurizing products which are inert to water and humidity, giving no release of hydrogen and not even agglomerating, under severe conditions of storage or use. These products have improved safety in use.
- coated magnesium was prepared according to Example 1 of EP 292 205; 25 g were immersed in water at pH 7 and 19 ° C, and a regular evolution of 50 cm3 of hydrogen was observed per hour.
- a desulfurizing product was prepared containing 20% of product No. 1 and 80% of a pulverulent mixture of composition (% by weight):
- Such a product according to the invention is particularly suitable for use in admixture with a powder also of calcium carbide. It has great storage security in hot environments, on the other hand, it is sensitive to water due to the presence of calcium carbide on the surface.
- This product was injected in the same liquid iron as in Example 1 with the same proportion of 0.1%. The final sulfur content obtained is 0.005%.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Ceramic Products (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Paints Or Removers (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
Description
L'invention concerne un produit pour désulfuration des fontes ou aciers liquides, à base de particules de magnésium enrobées.The invention relates to a product for desulfurization of cast irons or liquid steels, based on coated magnesium particles.
L'emploi du magnésium en poudre est bien connu pour la désulfuration de la fonte et de l'acier. Toutefois, de par sa tension de vapeur élevée à la température des bains de fonte ou d'acier liquides, le magnésium présente des difficultés d'emploi que l'on tente de surmonter en enrobant les particules de magnésium, dont le diamètre est en général inférieur à 2 mm, d'une couche de produit minéral en poudre fine constituée de grains dont le diamètre est en général inférieur à 150 microns.The use of magnesium powder is well known for the desulfurization of cast iron and steel. However, due to its high vapor pressure at the temperature of liquid iron or steel baths, magnesium presents difficulties of use which we try to overcome by coating the particles of magnesium, the diameter of which is generally less than 2 mm, a layer of fine powder mineral product consisting of grains whose diameter is generally less than 150 microns.
Différents moyens ont été proposés pour faire adhérer les grains du produit minéral sur les particules de magnésium. Par exemple l'adhérence peut être effectuée à l'aide de liants organiques ce qui présente certains avantages.Various means have been proposed for adhering the grains of the mineral product to the magnesium particles. For example, the adhesion can be carried out using organic binders which has certain advantages.
Ainsi dans le brevet FR 2 331 618 (AIKOH) le magnésium est d'abord mouillé par un liant organique, la poudre minérale est ensuite ajoutée pour obtenir finalement des grains de Mg entourés d'une pellicule organique elle-même recouverte d'une couche de produit minéral qui adhère donc au magnésium par l'intermédiaire de ladite pellicule organique.Thus in patent FR 2 331 618 (AIKOH) the magnesium is first wetted with an organic binder, the mineral powder is then added to finally obtain Mg grains surrounded by an organic film itself covered with a layer of mineral product which therefore adheres to magnesium via said organic film.
Les produits organiques plus particulièrement cités dans ce brevet sont:
- . l'amidon, la dextrine, les mélasses, qui sont des sucres, la carboxyméthylcellulose, les résines phénoliques, les résines à base d'urée, les résines mélamine, les résines furanne, les résines epoxy, les résines polyester, la poix et le goudron.
- . starch, dextrin, molasses, which are sugars, carboxymethylcellulose, phenolic resins, urea resins, melamine resins, furan resins, epoxy resins, polyester resins, pitch and tar.
De même la demande EP 292 205 décrit un enrobage similaire où le magnésium est d'abord recouvert d'une première couche d'un produit hydrophobe puis d'une deuxième couche d'un produit réfractaire particulaire. Ces produits hydrophobes qui sont également des produits organiques, sont sélectionnés parmi les huiles liquides aliphatiques ou aromatiques avec une basse viscosité à 25°C, ou solides à température ambiante mais liquides à des températures peu élevées (par exemple cires ou paraffine).Similarly, application EP 292 205 describes a similar coating where the magnesium is first covered with a first layer of a hydrophobic product and then with a second layer of a particulate refractory product. These hydrophobic products which are also organic products, are selected from aliphatic or aromatic liquid oils with a low viscosity at 25 ° C, or solid at room temperature but liquid at low temperatures (for example waxes or paraffin).
Le produit minéral réfractaire utilisé est en général constitué par les oxydes métalliques, des mélanges ou des complexes d'oxydes (par exemple: MgO, Al₂O₃, SiO₂, TiO₂, vermicullite,...), par des fluorures, par du carbone...The refractory mineral product used generally consists of metal oxides, mixtures or complexes of oxides (for example: MgO, Al₂O₃, SiO₂, TiO₂, vermicullite, ...), fluorides, carbon. .
Les produits désulfurants, à base de magnésium enrobé, obtenus à l'aide de ces produits organiques présentent cependant des inconvénients.
Tout d'abord ils ne sont pas totalement étanches à l'humidité ce qui provoque un dégagement d'hydrogène en cas de contact avec de l'eau (liquide ou vapeur); ce dégagement d'hydrogène présente évidemment un risque qui doit être évité.
De plus une faible élévation de température peut provoquer le ramollissement de la matière organique et entraîner ainsi une détérioration du revêtement réfractaire des grains de magnésium; il en résulte un risque de collage et d'agglomération des grains entre eux entraînant des difficultés et irrégularités de mise en oeuvre lors de l'introduction de l'agent désulfurant dans le métal liquide. Ces élévations de température néfastes se produisent généralement lors du stockage des produits dans des lieux exposés, par exemple proximité de fours, rayonnement du soleil...Desulfurizing products, based on coated magnesium, obtained using these organic products have drawbacks, however.
First of all, they are not completely impermeable to humidity, which gives off hydrogen in the event of contact with water (liquid or vapor); this release of hydrogen obviously presents a risk which must be avoided.
In addition, a slight rise in temperature can cause softening of the organic matter and thus cause deterioration of the refractory coating of the magnesium grains; this results in a risk of sticking and agglomeration of the grains between them, causing difficulties and irregularities in processing during the introduction of the desulfurizing agent into the liquid metal. These harmful temperature rises generally occur during the storage of the products in exposed places, for example near ovens, radiation of the sun ...
Compte tenu de ces inconvénients, la demanderesse a recherché un produit organique suffisamment résistant à la température, tout en étant de mise en oeuvre facile et garantissant une parfaite protection contre l'humidité.Given these drawbacks, the applicant has sought an organic product which is sufficiently resistant to temperature, while being easy to use and guaranteeing perfect protection against humidity.
L'invention est un produit pour désulfuration des fontes ou aciers liquides à base de grains de magnésium enrobés à l'aide d'un produit organique et d'une poudre réfractaire caractérisé en ce que le produit organique est à base d'acides aliphatiques saturés ou de leurs esters solides à température ordinaire.
On utilise habituellement des acides ou esters solides à basse température, de préférence en-dessous de 60°C ou mieux de 80°C, le point de fusion n'excédant pas généralement 110°C, avec une fusion franche, sans passer par une phase de ramollissement.The invention is a product for desulfurization of cast irons or liquid steels based on magnesium grains coated with a product. organic and a refractory powder characterized in that the organic product is based on saturated aliphatic acids or their solid esters at ordinary temperature.
Solid acids or esters are usually used at low temperature, preferably below 60 ° C or better of 80 ° C, the melting point not generally exceeding 110 ° C, with a clear melting, without going through a softening phase.
Les esters habituellement utilisés sont les triesters de la glycérine ou leurs mélanges, en particulier les triesters saturés obtenus par hydrogénération de l'huile de ricin, qui conduit essentiellement à du trihydroxystéarate de glycérol. L'huile de tournesol hydrogénée, le stristéarate de glycérol et parfois l'acide stéarique sont également utilisables.The esters usually used are the glycerine triesters or their mixtures, in particular the saturated triesters obtained by hydrogenation of castor oil, which essentially leads to glycerol trihydroxystearate. Hydrogenated sunflower oil, glycerol stristearate and sometimes stearic acid can also be used.
Ces produits ont un poids moléculaire élevé, avec un nombre d'atome de C en général égal ou supérieur à 16 pour les acides, à 51 pour leurs triesters.These products have a high molecular weight, with a number of C atoms generally equal to or greater than 16 for acids, to 51 for their triesters.
On voit que les produits d'enrobage solides de l'invention permettent d'une part de confectionner un revêtement de Mg stable à température élevée, sans qu'il soit nécessaire de procéder à des transformations chimiques de produits de départ pour l'obtenir. On peut rappeler d'autre part qu'avec ce revêtement stable une poudre de Mg peut supporter des conditions de stockage sévères en température (proximité de fours, soleil...) sans que sa coulabilité soit détériorée.It can be seen that the solid coating products of the invention make it possible, on the one hand, to make a coating of Mg which is stable at high temperature, without it being necessary to carry out chemical transformations of starting materials to obtain it. It may also be recalled that with this stable coating, an Mg powder can withstand severe temperature storage conditions (proximity of ovens, sun, etc.) without its flowability being deteriorated.
Les esters de l'invention constituent généralement la majeure partie ou de préférence la totalité du produit organique servant à l'enrobage du magnésium. Ainsi ledit produit organique peut contenir d'autres produits organiques que les esters de l'invention, en particulier des résidus non transformés des produits ayant servi à l'obtention desdits esters.
Ils conviennent particulièrement à l'enrobage du magnésium sur lequel ils adhèrent remarquablement grâce à leur acidité non nulle, mais faible qui permet de réagir très superficiellement avec les particules de Mg. Par exemple l'huile de ricin hydrogénée a un indice d'acidité de 4 (qui représente le poids de KOH en mg pour neutraliser 1 g de produit) et fond à 86°C.The esters of the invention generally constitute most or preferably all of the organic product used for coating the magnesium. Thus said organic product may contain other organic products than the esters of the invention, in particular unprocessed residues of the products used to obtain said esters.
They are particularly suitable for coating magnesium on which they adhere remarkably thanks to their non-zero but low acidity which makes it possible to react very superficially with the Mg particles. For example hydrogenated castor oil has an acid number of 4 (which represents the weight of KOH in mg to neutralize 1 g of product) and melts at 86 ° C.
Comme produit réfractaire de revêtement, on peut utiliser tous oxydes métalliques infusibles ou autres réfractaires en poudre connus de l'art antérieur, mais également des agents désulfurants comme C₂Ca, CO₃Ca, CaO... ou d'autres minéraux comme les carbones... ou leurs mélanges.As a refractory coating product, any infusible metal oxides or other powdered refractories known from the prior art can be used, but also desulphurizing agents such as C₂Ca, CO₃Ca, CaO ... or other minerals such as carbons ... or their mixtures.
Dans le cas où le produit réfractaire est sensible à l'humidité, comme par exemple C₂Ca, il est avantageux de l'enrober préalablement par un produit organique, de préférence ceux déjà cités, avant d'en revêtir Mg selon l'invention.In the case where the refractory product is sensitive to humidity, such as for example C₂Ca, it is advantageous to coat it beforehand with an organic product, preferably those already mentioned, before coating it with Mg according to the invention.
Mais la demanderesse a trouvé qu'il était avantageux d'utiliser comme produit réfractaire, servant donc à revêtir les grains d'agents magnésium à l'aide des esters selon l'invention, un laitier sous forme de grains ayant la composition suivante (en % poids):
- CaO
- 54 à 60%
- MgO
- 3 à 7%
- SiO₂
- 24 à 30%
- Al₂O₃
- 9 à 13%
- CaO
- 54 to 60%
- MgO
- 3 to 7%
- If
- 24 to 30%
- Al₂O₃
- 9 to 13%
Un tel laitier électrofondu en poudre présente les avantages suivants:
- . à la température des bains de fonte ou d'acier en fusion, il est à peu près en équilibre thermodynamique avec le magnésium avec lequel il ne réagit donc pratiquement pas; on évite ainsi une consommation parasite de magnésium;
- . si on le fabrique par fusion, il donne lieu, après coulée, à une transformation allotropique qui, au cours du refroidissement, le transforme naturellement en une poudre fine constituée de grains de diamètre moyen 40 µm environ.
- . il a une conductibilité thermique d'environ 0,5 Wm⁻¹K⁻¹ significativement plus faible que celle des oxydes habituels dans les mêmes conditions et donc favorise un effet retard dans l'action du magnésium dont les réactions sont jugées trop rapides et trop violentes.
- . at the temperature of baths of cast iron or molten steel, it is almost in thermodynamic equilibrium with magnesium with which it therefore practically does not react; this avoids parasitic consumption of magnesium;
- . if it is manufactured by fusion, it gives rise, after casting, to an allotropic transformation which, during cooling, transforms it naturally into a fine powder made up of grains with an average diameter of about 40 μm.
- . it has a thermal conductivity of about 0.5 Wm⁻¹K⁻¹ significantly lower than that of the usual oxides under the same conditions and therefore promotes a delay effect in the action of magnesium whose reactions are considered too rapid and too violent .
Les particules de magnésium ont une taille habituellement inférieure à 2 mm, de préférence comprise entre 300 et 800 µm environ et la poudre de produit réfractaire une taille de grains comprise entre 0 et 80 µm environ.The magnesium particles are usually less than 2 mm in size, preferably between 300 and 800 μm approximately and the refractory product powder has a grain size between 0 and 80 μm approximately.
On utilise en général 0,5 à 1,5 parties en poids d'ester selon l'invention (par exemple d'huile de ricin hydrogénée) pour 5 parties en poids de produit réfractaire de protection, le plus souvent environ 1 partie d'ester pour 5 parties de laitier de protection. La proportion de produit d'enrobage par rapport à l'agent désulfurant peut aller de 2% à 25% (poids).In general, 0.5 to 1.5 parts by weight of ester according to the invention are used (for example hydrogenated castor oil) per 5 parts by weight of refractory protection product, most often about 1 part of ester for 5 parts of protective slag. The proportion of coating product relative to the desulphurizing agent can range from 2% to 25% (weight).
Le produit désulfurant à base de magnésium enrobé selon l'invention peut être mélangé avec d'autres agents désulfurants, en particulier avec le carbure de calcium, ou avec d'autres mélanges à base de carbure de calcium (par exemple mélange du type carbonate de calcium + carbure de calcium + carbone), avec ou sans chaux. Il peut également être mélangé avec des produits inertes.The magnesium desulfurizing product coated according to the invention can be mixed with other desulfurizing agents, in particular with calcium carbide, or with other mixtures based on calcium carbide (for example mixture of the carbonate type of calcium + calcium carbide + carbon), with or without lime. It can also be mixed with inert products.
Pour obtenir le produit désulfurant selon l'invention on peut procéder de la façon suivante:
on introduit simultanément dans un mélangeur chauffé les particules de magnésium et l'ester selon l'invention à l'état solide de façon à produire dans un premier temps des particules uniformément recouvertes d'ester; on introduit alors la poudre de produit réfractaire et on obtient alors des particules recouvertes de laitier que l'on sort du mélangeur puis refroidit.To obtain the desulfurizing product according to the invention, it is possible to proceed as follows:
the magnesium particles and the ester according to the invention in the solid state are introduced simultaneously into a heated mixer so as to initially produce particles uniformly covered with ester; the refractory product powder is then introduced and particles coated with slag are then obtained which are removed from the mixer and then cooled.
Ainsi l'invention permet d'obtenir des produits désulfurants inertes à l'eau et à l'humidité, ne donnant aucun dégagement d'hydrogène et ne s'agglomérant pas même, dans des conditions sévères de stockage ou d'utilisation. Ces produits présentent une sûreté d'emploi améliorée.Thus, the invention makes it possible to obtain desulfurizing products which are inert to water and humidity, giving no release of hydrogen and not even agglomerating, under severe conditions of storage or use. These products have improved safety in use.
On a préparé selon le procédé décrit ci-dessus différents produits pour désulfuration à base de magnésium, d'huile de ricin hydrogénée et de poudre de laitier comprise entre 0 et 80 µm, également décrits ci-dessus.Various products for desulfurization based on magnesium, hydrogenated castor oil and slag powder of between 0 and 80 μm, also described above, were prepared according to the method described above.
Ces produits ont été injectés à une dose de 0,1% dans une fonte liquide à désulfurer à 1350°C contenant 0,05% de soufre. Les caractéristiques et les résultats sont donnés dans le tableau suivant :
Tous ces produits sont inertes à l'eau, c'est-à-dire que quand on les immerge dans l'eau à pH7 on ne constate aucun dégagement d'hydrogène, résultat confirmé après 2 heures d'immersion.
On note que l'effet retard augmente avec la quantité de produit réfractaire et tend à améliorer la qualité de la fonte obtenue, jusqu'à une certaine limite.All these products are inert to water, that is to say that when they are immersed in water at pH 7, no hydrogen is observed, result confirmed after 2 hours of immersion.
It is noted that the delay effect increases with the quantity of refractory product and tends to improve the quality of the cast iron obtained, up to a certain limit.
En comparaison, le même essai d'immersion pendant 2 h a été effectué avec des particules de magnésium revêtues selon l'art antérieur.
Ainsi, on a préparé du magnésium enrobé selon l'exemple 1 de la demande EP 292 205; on en a immergé 25 g dans de l'eau à pH 7 et 19°C, et on a observé un dégagement régulier de 50 cm³ d'hydrogène à l'heure.In comparison, the same immersion test for 2 h was carried out with magnesium particles coated according to the prior art.
Thus, coated magnesium was prepared according to Example 1 of EP 292 205; 25 g were immersed in water at pH 7 and 19 ° C, and a regular evolution of 50 cm³ of hydrogen was observed per hour.
Un dégagement d'hydrogène similaire a été observé dans les mêmes conditions avec du magnésium revêtu par une résine phénolique et de la magnésie selon l'enseignement du brevet FR 2331618.A similar evolution of hydrogen was observed under the same conditions with magnesium coated with a phenolic resin and with magnesia according to the teaching of patent FR 2331618.
On a préparé un produit désulfurant contenant 20% du produit N° 1 et 80% d'un mélange pulvérulent de composition (% poids):
Ce produit a été injecté dans la même fonte liquide que dans l'Exemple 1, à une dose de 0,25%. La teneur finale en soufre obtenue a été de 0,012%.This product was injected into the same liquid iron as in Example 1, at a dose of 0.25%. The final sulfur content obtained was 0.012%.
On a préparé selon le procédé décrit ci-dessus un mélange à base de magnésium, d'huile de ricin hydrogénée et de carbure de calcium micronisé, de composition:
- Mg (300-800 µm)
- 80%
- Huile de ricin hydrogénée
- 3%
- C₂Ca (inférieur à 100 µm)
- 17%
- Mg (300-800 µm)
- 80%
- Hydrogenated castor oil
- 3%
- C₂Ca (less than 100 µm)
- 17%
Un tel produit selon l'invention est particulièrement adapté pour être utilisé en mélange avec une poudre également de carbure de calcium. Il présente une grande sécurité de stockage en milieu chaud, par contre, il est sensible à l'eau du fait de la présence de carbure de calcium en surface.
Ce produit a été injecté dans la même fonte liquide que dans l'exemple 1 avec une même proportion de 0,1%. La teneur finale en soufre obtenue est de 0,005%.Such a product according to the invention is particularly suitable for use in admixture with a powder also of calcium carbide. It has great storage security in hot environments, on the other hand, it is sensitive to water due to the presence of calcium carbide on the surface.
This product was injected in the same liquid iron as in Example 1 with the same proportion of 0.1%. The final sulfur content obtained is 0.005%.
L'inconvénient ci-dessus a été évité, dans un essai complémentaire, sans altérer la sécurité du stockage en milieu chaud, en enrobant C₂Ca à l'aide de 1% (par rapport à C₂Ca) d'huile de ricin hydrogénée avant de l'introduire dans le mélangeur contenant Mg enrobé.The above drawback was avoided, in a complementary test, without altering the safety of storage in a hot environment, by coating C₂Ca with 1% (relative to C₂Ca) of hydrogenated castor oil before l '' introduce into the mixer containing Mg coated.
Claims (10)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT91420388T ATE95249T1 (en) | 1990-11-05 | 1991-10-30 | COATED MAGNESIUM PARTICLES FOR DESULPHURIZATION OF CAST IRON OR MILD STEEL. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9014092 | 1990-11-05 | ||
| FR9014092A FR2668776B1 (en) | 1990-11-05 | 1990-11-05 | PRODUCT FOR DESULFURIZING CAST IRONS OR LIQUID STEELS BASED ON COATED MAGNESIUM. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0485309A1 true EP0485309A1 (en) | 1992-05-13 |
| EP0485309B1 EP0485309B1 (en) | 1993-09-29 |
Family
ID=9402139
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP91420388A Expired - Lifetime EP0485309B1 (en) | 1990-11-05 | 1991-10-30 | Product based on coated magnesium for the desulphurizing of cast iron or liquid steel |
Country Status (13)
| Country | Link |
|---|---|
| US (1) | US5198016A (en) |
| EP (1) | EP0485309B1 (en) |
| AT (1) | ATE95249T1 (en) |
| CS (1) | CS334791A3 (en) |
| DE (1) | DE69100441T2 (en) |
| ES (1) | ES2046031T3 (en) |
| FI (1) | FI96518C (en) |
| FR (1) | FR2668776B1 (en) |
| HU (1) | HUT61344A (en) |
| NO (1) | NO177391C (en) |
| PL (1) | PL292273A1 (en) |
| PT (1) | PT99419B (en) |
| SK (1) | SK280853B6 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0511121B1 (en) * | 1991-04-02 | 1996-09-11 | Pechiney Electrometallurgie | Desulfurisation agent for pig iron, comprising calcium carbide and an organic binder |
| WO2009019310A1 (en) * | 2007-08-09 | 2009-02-12 | Basf Se | Coating compound for expandable styrol polymer particles |
| CN103773914A (en) * | 2012-10-23 | 2014-05-07 | 刘秀凤 | Preparation method for composite desulphurization material used for iron casting |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1087035C (en) * | 1999-11-02 | 2002-07-03 | 北京科技大学 | Technology for pretreating molten iron inshallow smelting bath by blowing Mg-base desulfurizing agent |
| CN102061358B (en) * | 2011-01-17 | 2012-12-26 | 中国恩菲工程技术有限公司 | Desulfuration refining process of high-sulfur crude ferronickel |
| CN102108428B (en) * | 2011-01-17 | 2013-04-03 | 中国恩菲工程技术有限公司 | Refining process of crude nickel iron |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2331618A1 (en) * | 1975-11-14 | 1977-06-10 | Aikoh Co | MELT IRON DESULFURATION PROCESS |
| US4533572A (en) * | 1984-03-20 | 1985-08-06 | Amax Inc. | Process for producing varnish-bonded carbon-coated metal granules |
| EP0292205A1 (en) * | 1987-05-22 | 1988-11-23 | Foseco International Limited | Metallurgical treatment agents |
| EP0328270A2 (en) * | 1988-02-09 | 1989-08-16 | Foseco International Limited | Metallurgical treatment agents |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2536362A (en) * | 1949-12-19 | 1951-01-02 | Du Pont | Treatment of molten metals |
| US3410681A (en) * | 1965-09-28 | 1968-11-12 | Fur Tech Entwicklung Und Verwe | Composition for the treatment of steel |
-
1990
- 1990-11-05 FR FR9014092A patent/FR2668776B1/en not_active Expired - Fee Related
-
1991
- 1991-10-30 NO NO914257A patent/NO177391C/en not_active IP Right Cessation
- 1991-10-30 AT AT91420388T patent/ATE95249T1/en not_active IP Right Cessation
- 1991-10-30 DE DE91420388T patent/DE69100441T2/en not_active Expired - Fee Related
- 1991-10-30 EP EP91420388A patent/EP0485309B1/en not_active Expired - Lifetime
- 1991-10-30 ES ES91420388T patent/ES2046031T3/en not_active Expired - Lifetime
- 1991-11-04 FI FI915188A patent/FI96518C/en active
- 1991-11-04 PT PT99419A patent/PT99419B/en not_active IP Right Cessation
- 1991-11-04 PL PL29227391A patent/PL292273A1/en unknown
- 1991-11-05 HU HU913471A patent/HUT61344A/en unknown
- 1991-11-05 CS CS913347A patent/CS334791A3/en unknown
- 1991-11-05 SK SK3347-91A patent/SK280853B6/en unknown
- 1991-11-05 US US07/788,022 patent/US5198016A/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2331618A1 (en) * | 1975-11-14 | 1977-06-10 | Aikoh Co | MELT IRON DESULFURATION PROCESS |
| US4533572A (en) * | 1984-03-20 | 1985-08-06 | Amax Inc. | Process for producing varnish-bonded carbon-coated metal granules |
| EP0292205A1 (en) * | 1987-05-22 | 1988-11-23 | Foseco International Limited | Metallurgical treatment agents |
| EP0328270A2 (en) * | 1988-02-09 | 1989-08-16 | Foseco International Limited | Metallurgical treatment agents |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0511121B1 (en) * | 1991-04-02 | 1996-09-11 | Pechiney Electrometallurgie | Desulfurisation agent for pig iron, comprising calcium carbide and an organic binder |
| WO2009019310A1 (en) * | 2007-08-09 | 2009-02-12 | Basf Se | Coating compound for expandable styrol polymer particles |
| CN101778890B (en) * | 2007-08-09 | 2012-04-11 | 巴斯夫欧洲公司 | Coating compound for expandable styrol polymer particles |
| RU2475502C2 (en) * | 2007-08-09 | 2013-02-20 | Басф Се | Agent for coating spumescent particles of styrene polymerisate |
| CN103773914A (en) * | 2012-10-23 | 2014-05-07 | 刘秀凤 | Preparation method for composite desulphurization material used for iron casting |
Also Published As
| Publication number | Publication date |
|---|---|
| FI915188A0 (en) | 1991-11-04 |
| NO914257L (en) | 1992-05-06 |
| FI96518C (en) | 1996-07-10 |
| FI915188A (en) | 1992-05-06 |
| DE69100441T2 (en) | 1994-01-20 |
| EP0485309B1 (en) | 1993-09-29 |
| FR2668776A1 (en) | 1992-05-07 |
| NO177391B (en) | 1995-05-29 |
| NO177391C (en) | 1995-09-06 |
| ES2046031T3 (en) | 1994-01-16 |
| NO914257D0 (en) | 1991-10-30 |
| HUT61344A (en) | 1992-12-28 |
| DE69100441D1 (en) | 1993-11-04 |
| FI96518B (en) | 1996-03-29 |
| ATE95249T1 (en) | 1993-10-15 |
| CS334791A3 (en) | 1992-05-13 |
| PT99419B (en) | 1999-04-30 |
| PT99419A (en) | 1992-09-30 |
| US5198016A (en) | 1993-03-30 |
| PL292273A1 (en) | 1992-06-01 |
| HU913471D0 (en) | 1992-01-28 |
| FR2668776B1 (en) | 1994-05-13 |
| SK280853B6 (en) | 2000-08-14 |
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