REFRACTORY CERAMIC CHARGE, SAID CHARGE APPLICATION TYPE AND METALLURGICAL MELTING CAPACITY

Applicant RifrektoriIntellektchual Property GmbH Und To. KG, AT

The invention relates to refractory ceramic mixture for production of the besformennogo refractory ceramic product, to use of said charge type for lining of metallurgical melting containers, and also to metallurgical melting containers, which is lined amorphous tangle refractory ceramic product on the basis of charge of specified type.

Refractory ceramic mixture is known for designations mixture, composed of one or several components, as a result of which can be obtained refractory ceramic product by means of privilege ceramics. Term "refractory ceramic product" within value invention indicates in particular on ceramic products with working temperaturoyu, which is above 600 theoretically, and, mainly, on refractory materials in accordance with the standard with DIN 51060, in other words, on materials with refractoriness of by cone cone > PC 17.

Pyrometric cone cone can be determined, in particular in accordance with the standard with DIN array en 993 - 12.

Refractory ceramic products, in particular, also are known in the form of besformennykh refractory ceramic products, other words, so called "refractory mass".

Refractory mass in particular also is used for lining of metallurgical melting containers.

Mass for lining or coating metallurgical melting containers, in particular, also are known in the form of so called mass for erection of working space of furnace or mass for repair of working space of furnace, which is used for refractory lining of melting containers of said type, or also for restoration of lining of melting containers of said type.

Mass for structure of working space and mass for repair of working space for metallurgical melting containers is usually natural magnesium oxide, enriched iron and chalk, for example, magnesium oxide in the form of rock. Magnesium oxide of said type, enriched iron and chalk, preferably is used for production of mass for structure of working space furnace and mass for repair of working space of furnace, it forms ferrite dicalcium (2 CaO regoz;

Ca2fe20s), even at relatively low temperature. Said ferrite dicalcium melting phase forms on the surface of mass for structure of working space furnace or mass for repair of working space of furnace, facing inside space of metallurgical melting containers, even at relatively low temperatures. So, respectively located mass, and also sections of metallurgical melting containers, which are coated with mass, are protected from ingress of metal melt, the, until mass at high temperatures forms dense spechennyi layer, which metal melt barely detected is able to penetrate.

However natural magnesium oxide of said type, enriched iron and chalk, in many cases is inaccessible. In such cases, as known in the level of equipment, should be is made synthetic magnesium oxide, enriched iron and chalk. For manufacturing of the specified type synthetic magnesium oxide, enriched iron and chalk, preliminarily mixed magnesite with low content of iron, dolomite and carrier iron oxide, for example, mill scale, is formed into briquettes and then is burned at high temperature in rotary furnace, except where synthetic magnesium oxide, in particular also is formed ferrite dicalcium, which is critically important for functioning mass, obtained from magnesium oxide, as was explained above.

However, deficiency manufacturing of the specified type synthetic magnesium oxide, enriched iron and chalk, for example, is, that said magnesium oxide should burned in its own rotating furnace, since furnace reagents initial materials, which are used for manufacturing synthetic magnesium oxide. For example, natural magnesium oxide with low content of iron and chalk can not burned in furnace said type, it will foul initial materials, which are used for manufacturing synthetic magnesium oxide, enriched iron and chalk.

To the same, mass for structure of working space furnace and mass for repair of working space of furnace is known in the level of equipment, as such, which is made from charge, which contains spechennyi magnesium oxide, obozhzhennyi dolomite and, if it is required, carriers iron oxide. Obozhzhennyi dolomite, however, has strong tendency gidratirovatsya, means that is, that the charge, which contains obozhzhennyi dolomite said type, has only limited service life.

Effect, which should be thus by means of the invention, consists in provision of the refractory ceramic charge on base of magnesium oxide with low content of iron for production of refractory mass, which has mainly such same properties, as and mass, which is made based on natural magnesium oxide, enriched iron and chalk. Additional effect, which should be thus by means of the invention, consists in provision of the charge on base of magnesium oxide with low content of iron for production of mass, which forms molten layer even at relatively low temperatures. Additional effect, which should be thus by means of the invention, consists in provision of the charge on base of magnesium oxide with low content of iron for production of mass, which forms melt at relatively low temperatures, and forms tightly spechennyi layer at high temperatures. Additional effect, which should be thus by means of the invention, consists in provision of the charge of said type on the basis of magnesium oxide with low content of iron for production of mass, which forms melt at low temperatures and forms dense spechennyi layer at high temperatures, for lining of metallurgical melting containers. Additional effect, which should be thus by means of the invention, consists in provision of the charge of said type on the basis of magnesium oxide with low content of iron for production of mass, which has good service life.

For solving said problems, is refractory ceramic charge according to invention for production of besformennogo refractory ceramic product, which contains the following initial materials:

- one or several initial materials based on magnesium oxide with low content of iron with fraction in the range, which is 66 - 94% by mass;

- one or several initial materials based on calcium carbonate with fraction in the range, which is 5 - 30% by mass;

- iron powder with fraction in the range, which is 1 6% by mass.

Unexpectedly, according to invention revealed, that besformennyi refractory ceramic product, in other words mass, which demonstrates mainly such same properties, as and mass, produced based on natural magnesium oxide, enriched iron and chalk, may be obtained by means of refractory ceramic charge, which contains of said initial materials.

Unexpectedly, according to invention revealed, that application in charge according to invention iron powder, combined with initial materials based on calcium carbonate, results in the formation of ferrite dicalcium at temperatures from approximately 1000 to 1200 theoretically, which forms rasplavlenii layer on the surface of mass. So, mass is protected from furnace atmosphere or any - or molten metal, which there is already in furnace at low temperatures such, to the, as mass will form tightly spechennoe monolithic formation at high temperatures. According to invention revealed, that in the said case iron powder enters in reaction with initial materials based on calcium carbonate considerably better, than initial materials based on iron oxide, so, that formation of ferrite dicalcium for protection of mass guaranteed.

According to invention was shown, that iron powder charge according to invention in reaction, starting from approximately from 600 theoretically, with formation of iron oxide (of II) (of FeO). Starting from approximately from 1000 theoretically, from iron oxide (of II) or iron powder is formed iron oxide (of III) (begoz), in particular in oxidizing atmosphere. To the same, further calcium carbonate initial material calcium carbonate based the above temperatures kaltsiniruetsya, so, that calcium carbonate in the initial materials based on calcium carbonate forms calcium oxide (CaO). Iron oxide (of II) enters in reaction with magnesium oxide in the initial materials based on magnesium oxide to produce ferrite magnesium, while iron oxide (of III), in particular, enters in reaction with calcium oxide to produce ferrite dicalcium, starting from approximately from 1000 theoretically. In the said case, is formed more ferrite magnesium in heavily reducing atmosphere, while larger amount of ferrite dicalcium is formed in the heavily oxidizing atmosphere. Starting from temperature, which is approximately 1200 theoretically, ferrite dicalcium melting phase forms on the surface of mass, which properly protects mass, which more has not been tightly sintered, from penetration of furnace atmosphere or any - or molten metal, which there is already in metallurgical melting containers. At high temperatures, in particular at temperatures from approximately 1400 theoretically to 1600 theoretically, in other words, normal working temperatures mass in metallurgical melting fires, mass forms tightly spechennoe refractory ceramic monolithic formation, which contains, in particular, phase periclase (of MgO), vustita ((of Mg, of Fe) 0) and CaO.

Other advantage of charge according to invention is, that it demonstrates exclusively stable phase, so, that the charge has very good service life.

In particular, according to invention can be is provided, that fraction iron in the initial materials based on magnesium oxide with low content of iron, determined as begoz, and to total mass of initial materials with low content of iron, is less than

1.5% by mass, also, for example, less than 1.4% weight, 1.3% by mass,

1.2% by mass, 1.1% by mass, 1.0% by weight or 0.9% by mass. Said digits field to the total mass of initial materials with low content of iron, so, that in case of, coli is used different initial materials based on magnesium oxide, which have low content of iron, separate initial materials from said may also demonstrate fraction iron, if it is required, exceeds that of said digits, until total mass of initial materials based on magnesium oxide with low content of iron is located below of above mentioned fractions iron.

The same appropriate way is applied to fraction calcium in the initial materials based on magnesium oxide with low content of iron. In the said case, calcium, determined as CaO, and to total mass of initial materials with low content of iron, can be less than 5% by mass, for example, also less than 4, 3 or 2% by mass.

Except iron (begoz) and CaO, initial materials based on magnesium oxide may, for example, contain fraction of at least one of the following components: ai2o3 (preferably less than 1 or 0.5% by mass), si02 (preferably less than 5, 4, 3, 2, 1% by mass) or B2O3 (preferably less than 0.5 or 0.4% by weight, 0.3% by weight, 0.2% by weight or 0.1% by mass).

Fraction of magnesium oxide (of MgO) in the initial materials based on magnesium oxide with low content of iron, again to the total mass of initial materials with low content of iron, is preferably above 90% by mass, also for example, above 91, 92, 93, 94, 95, 96, 97 or

98% by mass.

Digits, said here in % by weight, in each case, field to the total mass of refractory ceramic charge according to invention, until the other as indicated in separate cases.

Initial materials based on magnesium oxide with low content of iron can, for example, be present in form of at least one of the following initial materials: fused magnesium oxide or spechennyi magnesium oxide.

Initial material based on magnesium oxide or initial materials based on magnesium oxide can be present in charge in the fraction, which is within range, which is 66 - 94% by mass, for example, also in fraction, which is at least 68, 70, 72, 73, 74, 75 or 76% by mass and, for example, in fraction, which is maximum 93, 92, 91, 90, 89 or 88% by mass.

Preferably may be is provided, that initial materials based on magnesium oxide with low content of iron have grain size, which is maximum 10 mm, in particular, for example, which is maximum 9, 8, 7, 6 or 5 mm.

Initial materials based on calcium carbonate in charge in accordance with the invention can, for example, be present in form of at least one of the following initial materials: limestone, marble or dolomite.

Preferably may be is provided, that fraction of calcium carbonate in materials based on calcium carbonate, to the total mass of initial material based on calcium carbonate, is higher than 90% by mass, for example, also above 91, 92, 93, 94, 95, 96, 97, 98 or 99% by mass.

Can be is provided, for example, that initial materials based on calcium carbonate are presented exclusively in the form of limestone.

Initial material calcium carbonate based or initial materials based on calcium carbonate can be present in charge in the fraction in the range of range, which is 5 - 30% by weight, for example, also in fraction, which is at least 6, 7, 8 or 9% by mass and, for example, in fraction, which is maximum 29, 28, 27, 26, 25, 24, 23, 22 or

21% by mass.

According to invention revealed, that if it is possible, then only a small fraction of calcium oxide, required for formation of ferrite dicalcium, should be provided dolomitom. Said is outcome of the, by means of that dolomite charge is introduced additional magnesium oxide, since magnesium carbonate in dolomite kaltsiniruetsya in magnesium oxide, when is used charge. In this sense, at least and possibly to reduce fraction of initial materials based on magnesium oxide in charge, mass properties, obtained from charge, deteriorating, since application of charge causes not only calcination of initial material based on calcium carbonate, and and additional calcination of initial materials in charge, as additionally kaltsiniruetsya magnesium carbonate from initial materials in the form of dolomite. In this sense, present preferable, when fraction dolomite in charge according to invention will be limited to fraction, which is maximum 15% by mass.

In sense, that initial materials based on calcium carbonate also partially are in the form of dolomite, along this cause of may, for example, be ensured, that they attended only in small fraction together with initial materials in the form of limestone. Can be is provided, for example, to dolomite attended in charge only in fraction, which is maximum 15% by mass, for example, also in fraction, which is maximum 14, 12, 10, 8, 6, 4, 3, 2 or 1% by mass.

Initial materials based on calcium carbonate preferably have grain size, which is maximum 8 mm, for example, also, which is maximum 7, 6 or 5 mm. For example, may additionally be ensured, to initial materials based on calcium carbonate have grain size, which is at least 1 mm, for example, also at least 2 or 3 mm. Above given digits relative to grain size of initial materials based on calcium carbonate can relates to the whole fraction of initial materials or, for example, also to the fraction, which is at least 90% by weight of initial materials, to the total mass of initial materials based on calcium carbonate.

Iron powder can be presented in charge in the fraction in the range of range, which is 1 - 6% by weight, for example, also in fraction, which is at least 1.2% by mass, 1.4% by mass,

1.6% by mass, 1.8 or 1.9% by mass, and in fraction, which is maximum 5% by mass, 4% by mass, 3.8% weight, 3.6% by mass,

3.4% by mass, 3.3% by mass, 3.2% by weight or 3.1% by mass.

For passage of reaction between iron oxide (of III) and calcium oxide to produce ferrite dicalcium, present preferable, when iron oxide (of III) is present in from the minimum possible sizes of particles.

Said may be achieved, since iron powder is present in charge according to invention with a small grain size, preferably with particle size less than 0.5 mm, so, for example, also with particle size less than 0.4 mm, 0.3 mm, 0.2 mm or 0.1 mm. Said digits relative to grain size metal powder can relates to the whole fraction powder of iron or, for example, to the fraction, which is at least 90% by weight of iron powder, to the total mass of iron powder.

According to invention revealed, that the charge may have very sensitive reaction to other components. For example, other components may, in particular, prevent or of suppressing formation of ferrite dicalcium from iron oxide and calcium oxide. Said, for example, in particular, applicable to carbon, it will be of entering into reaction with with iron powder. Along this cause of, in particular can be is provided according to invention, that fraction of carbon in charge according to invention is less than 1% by mass.

Total as a rule, can be is provided, that fraction of initial materials, which are present in charge together with initial materials based on magnesium oxide, Secured according to invention, initial materials based on calcium carbonate, and also with iron powder, is less than 10% by mass, in particular preferably less than 9, 8, 7, 6 or

5% by mass.

To the same, can be is provided, to total mass of oxides of SiC>2 and ai2o3 in charge is less than 5% by mass, so for example, also less than 4, 3, or 2% by mass. Oxides and byug ai2o3 can, for example, be introduced into charge, in particular by means of impurities, which are present in the initial materials according to invention.

In addition, object of the invention is application of charge in according to invention for lining of metallurgical melting containers.

Said application may, for example, take place provided, that charge is made with application in besformennom courses ceramic product, in other words mass, of at least one plasticizer, and then metallurgical melting capacity proposed method manufactured amorphous tangle refractory ceramic product. In this sense, charge according to invention can in particular be used as mass for structure of working space furnace or mass for repair of working space of furnace.

Charge according to invention can, however, also be used as mass directly, without plasticizer.

For production of from charge besformennogo refractory ceramic product, in other words mass, initial materials charge can be thoroughly mixed with each other and, if it is necessary, possibly with addition of plasticizer.

Metallurgical melting capacity, which can futerovatsya charge according to invention, can, in principle, be a any capacity, which is used for holding of molten metal, for example, capacity, which is used for holding of molten metal, for example, electric arc furnace, in which melt metal is produced by means of electric arc.

Futerovanie of metallurgical melting containers in the said case means at least partial coating of metallurgical melting containers on sections, which will be in contact with metal melt, if they not covered or not are lined with amorphous tangle refractory ceramic product.

Object of the invention is also metallurgical melting capacity, which is lined amorphous tangle refractory ceramic product, where besformennyi refractory ceramic product is obtained from charge according to invention.

For production of from charge according to invention besformennogo refractory ceramic product, in other words, mass, said mass can be made preferably with use of plasticizer.

Plasticizer said type may be oil, for example, oil, which binds the powdered material, for example, at least one of the following oils: oil based on naftena, straw oil or sunflower oil. Plasticizer can be added to charge in the fraction in the range of range, which is 0.1 - 3% by weight, for example, to the total mass of charge without plasticizer.

Charge according to invention preferably is used in the form of dry mass, in other words, with plasticizer, if it is required, but without water.

The invention more detail is explained by means of the following indicative embodiment.

Object indicative embodiment are versions of mixture based on spechennogo magnesium oxide with low content of iron, which was is obtained from magnesite with low content of iron and chalk.

Spechennyi magnesium oxide, which was used in the indicative versions, that the following composition, in accordance with table 1, where digits, shown in the right stolbike, are given in % weight fraction relative to oxide, in each case, to the total mass of spechennogo magnesium oxide.

In the following table 2, it is shown three sample charge and, b and in versions of charge according to invention based on spechennogo magnesium oxide in accordance with table 1, where digits in wales corresponding versions of charge are given in % by mass, relative to the fraction of corresponding components total mass corresponding charge.

Initial material grain size charge and charge B charge in

Iron powder > 0 - 0, 3 mm 3 3 2

Table 2

Versions and charge and b is used as mass for repair of working space of furnace (mass for repair of in hot state), and charge in accordance approximate embodiment in is used as mass for structure of working space furnace (cold futerovanie) for lining of metallurgical melting containers.

For said target, versions and charge and b, each, izgotavlivali with addition of sunflower oil as plasticizer, in fraction, which is 0.5% by mass, relative to the common mass corresponding charge without sunflower oil, and then metallurgical melting capacity futerovali mass, made by means of said method.

Charge in accordance approximate embodiment in applied directly as mass without plasticizer, and the charge futerovali metallurgical melting capacity.

Additional symptoms of the invention flow out from the formula of invention. All signs, described in connection with the present invention, can arbitrary combinable with each other, separately or in combination.