EP0268679A1 - Material for alloying a metal with vanadium - Google Patents

Abstract

A material intended for alloying a metal with vanadium comprises a metallic component which is covered by an envelope consisting of an alloying component of the following composition, in per cent by weight: 10-24 of silicon oxide, 14-25 of vanadium oxide, 4-14 of manganese oxide, 3-10 of titanium oxide, 1-4 of chromium oxide, 3-50 of calcium oxide or/and of magnesium oxide, the balance being iron. In the said material the content of the metallic component, comprising carbon, metal and iron, is 5-95, the balance consisting of the alloying component. The material has the form of granules measuring 0.5-30.0 mm.

Description

Technical field

The present invention relates to the field of black metallurgy and in particular relates to a material for alloying a metal with vanadium.

Previous state of the art

In the pyrometallurgical production of vanadium-containing products such as pig iron, steel and alloys containing vanadium, the need for the use of vanadium-containing alloys, silicavanavanadin, ferrovanadin and others as alloying material has increased considerably. Deficient and relatively expensive vanadium pentoxide is required for the production of alloying vanadium alloys and especially ferrovanadium, and alloys containing vanadium are mainly used for alloying pig iron and steel with vanadium. This led to the search for new alloying substances containing vanadium. In this connection, it has been proposed to use vanadium-containing slag, which is obtained in the oxidation of pig iron-containing vanadium, as an alloying substance containing vanadium (SU, PS, A, 196064, C 21 05/52, published in 1967; SU, PS, A, 358374, C 21 C 5/52, published 1972; SU, PS; A, 394437 C 21 C 5/52, published 1973.

The slag used here has a mass%:

Additions (MgO, Al ₂ O ₃ R ₂ O) - rest.

The said slag was found in the book by NPLekishev and others "Vanadii v chernoi metallurgii" (Vanadin in black metallurgy), publisher "Metal - lurgiya ", Moscow, 1983, p. 36, however, due to a high degree of oxidation and a low content of calcium and vanadium oxides, the duration of alloying a metal with vanadium increases and consequently the productivity of the production of a finished vanadium-containing product decreases overall.

The same also applies to the use of vanadium-containing slags, which are produced in China and in the Republic of South Africa, as a substance containing vanadium.

The vanadium-containing slags made in China, in% by mass: vanadium oxide - from 10 to 15; Iron oxide from 33 to 45; Titanium oxide - from 8 to 13.5; Silicon oxide - from 7.6 to 35.4; Manganese oxide - from 2.7 to 5.7; Calcium oxide - from 0.9 to 1.5, are extremely low in vanadium and require a considerable consumption of accompanying reaction participants (flux and reducing agents) (see KNSokolova, "Proizvodstvo i potrebleniye vanadiya za rubezhom" (production and consumption of vanadium in Abroad), Bulletin of the Institute "Chermetinformaciya", 1981, Issue 10, pp. 3-15).

The vanadium-containing slags produced in the Republic of South Africa, the mass%: vanadium oxide 27.8; Iron oxide - 22.4; _C. Calcium oxide - 0.5, magnesium oxide -0.3; Silicon oxide - 17.3; Alumina - 3.5; Carbon - 3.5; Additions (TiO ₂ , MnO, Cr ₂ O ₃ ) - rest, (due to their chemical composition) can occur as a material for alloying metal with vanadium, which is characterized by good production-technical behavior, but in the literature concrete There is no information about the alloying of metal, so it can be said that a low concentration of calcium and magnesium oxides in this substance will lead to an increased consumption of flux and reducing agents when used.

The use of slag is also known Metallic materials that consist of a (vanadium-containing) slag component and a metal component that have any random shape and a homogeneous structure.

In Masee these substances have%:

The fabric is in the form of two-layer granules with a diameter of 5 to 20 mm. A considerable amount of carbon is contained in the surface layer of the granules, and the inner layer thereof is filled with a homogeneous solution of the oxides and the cement (SU-PS 926024 ₁ C 21 C 1/06, published 1982). The disadvantage of these alloying substances is that their dissolution in the metal is slow, which lengthens the alloying process and reduces the performance of the manufacturing process of a product containing vanadium.

This creates the problem of finding effective vanadium-containing substances that are used to alloy a metal with vanadium.

Disclosure of the invention

The object of the present invention is to search for such a material for alloying a metal with vanadium, which reduces the duration of the alloying and increases the performance of the production process of a product containing vanadium without deteriorating its quality.

dabei das Verhältnis zwischen der Metall- und Schlackenkomponente in Masse% wie folgt ist:

The object was achieved in that a material containing a metal component in the form of granules is proposed for alloying metal, which is characterized according to the invention in that its Metal component is coated with a coating of a slag component which has the following composition in mass%:

the ratio between the metal and slag components in mass% is as follows:

Mangan und Chrom zusammensetzt. Es wird empfohlen, die Abmessungen der Granalien des genannten Stoffes in einem Bereich von 0,5 bis 30,0 mm zu halten.A suitable variant of the substance mentioned is a substance in which the metal component has the following composition in mass%:

Manganese and chrome composed. It is recommended to keep the dimensions of the granules of the named substance in a range from 0.5 to 30.0 mm.

• - eine höhere Geschwindigkeit der Auflösung;
• - er bewirkt die Verringerung der Dauer des Legierens eines Metalls mit Vanadin;
• - er vergrößert das Ausbringen des Vanadins ins Metall und verringert die Kosten zum Legieren des letzteren mit Vanadin.

The substance according to the invention for alloying a metal with vanadium has the following advantages over the known substances:

• - a higher speed of dissolution;
• - it reduces the duration of alloying a metal with vanadium;
• - It increases the spreading of the vanadium into the metal and reduces the cost of alloying the latter with vanadium.

The main advantage of the substance according to the invention is that it relates extremely quickly in a liquid metal, for example in cast iron dissolve wisely in steel.

In contrast to metal materials (ferro alloys and ligatures), which are used as an alloying agent and which cannot sink completely into the metal when sinking down onto the poorly miscible floor of a sol-bath, and in contrast to the known slag metal materials, which on the contrary are completely located on the metal surface (as a result of a very developed - over 50% - porosity of the reduction iron), the substance according to the invention is immersed in the metal to 80 to 90% of its volume; therefore, it is actively mixed with the circulating metal streams, especially during decarburization or during another process for exciting the metal surface. The extremely high-melting and slag component firmly adhering to the metal component cannot be destroyed when the substance is heated until the "encapsulated" metal component breaks up into a large number of smaller drops as a result of the crude oxide formed in it. This explosive disintegration of the substance significantly increases the reaction surface of the interaction between the alloying substance and the liquid metal and consequently leads to a significant increase in the speed of its dissolution. The positive effect of the "encapsulation" of the metal component by the high-melting and chemically resistant slag component is mainly achieved in a certain range of grain sizes. If the grain size (average diameter) is less than 0.5 mm, the above-described effect will be weaker due to the insufficient thickness of the slag coating. Similarly, with a grain size above 30.0 mm, the effect of the "encapsulation" is reduced, which is obviously caused by a greater deformation of the slag coating (until it is destroyed) becomes, which leads to the premature elimination of carbon monoxide from the metal component.

The oxides, the ^g on the composition of a slag component of a Granalienüberzu include it, play a dual role. On the one hand, for example, the iron and silicon oxides form a silicate component that accelerates the reduction of the iron and vanadium oxides. On the other hand, the silicate component is solidified due to a substantial sorption against the vanadium and titanium oxides and especially against aen chromium oxides, which together with the iron oxides form a complex spinellide, and at the same time due to the presence of manganese oxides, it wets the metal component well, whereby a constant slag coating of the alloy substance is formed.

The alloying substance according to the invention will have the above-mentioned positive effect if the limit quantities for the components belonging to its composition are observed. If the silicon oxide content is below 10% and the vanadium oxide below 14%, the softening of the slag coating and consequently its premature destruction is demonstrated. A similar phenomenon is also demonstrated when the silicon oxide content is above 24% and the vanadium oxide above 25%.

The presence of manganese oxide in the stated range of 4 to 14% contributes to the complete wetting of the metal component of the slag coating, which is noticeably reduced when the manganese oxide concentration is below 4% or above 14%. The presence of titanium oxides in an amount of 3 to 10% and chromium oxide in an amount of 1 to 4% in a slag coating promotes the solidification of the complex iron-vanadium spinellide, which is dissolved in the silicate binder. The calcium or magnesium oxides in an amount of 3 to 50% promote the presence of iron and silicon oxides the formation of a chemically stable silicate component which has an increased sorption capacity compared to the complex iron-vanadium spinellide.

The ratio between the metal and slag component in the substance according to the invention makes it possible to productively alloy a metal with vanadium: the smallest grain size in a range from 0.5 to 1 mm corresponds to the increased metal component content of 70 to 95%, and in the case of the larger grain sizes of 20 to 30 mm, on the other hand, it is expedient that the alloying substance has 5 to 20% of the metal component. As a result, the oxides belonging to the composition of the substance, which form mineral, mutually detachable compounds, create a solid and chemically resistant topcoat coating on the surface of the granules, which prevents the premature destruction of the granules.

A firm adherence of the base coat with the metal component contained in it is promoted in that the zone connecting these two components during the formation of the substance is formed in the surface layer of the slag component. In this case, their strength reaches a significant size and it is extremely difficult to separate. This intermediate layer (transition layer) contains, in contrast to the usual fires that arise in the slag and metal materials, in addition to the silicon and iron oxides, also significant amounts of vanadium and titanium oxides, which form a phase that can be dissolved in iron silicates. A sufficiently low content (from 0.1 to 0.5%) of carbon in the transition layer also contributes to the firm adherence between the slag and metal components.

Metal iron with the carbon dissolved in it, which is located in the inner part of the granules blocked by the environment with the slag coating, which is why its oxidation during heating and melting is excluded, which in turn reduces the duration of the dissolution. The concentration range of the metal iron contributes to such immersion of the substance according to the invention in the metal, at which the greatest degree of its dissolution is achieved.

The composition of the slag coating of the substance can also include aluminum and phosphorus oxides in a total amount of 3 to 5%, which are considered additives for this substance and which get into the same with the substances with the help of which the main components are introduced. The above-mentioned oxides in the quantities mentioned do not have any negative influence on the rate of dissolution of the substance.

The above alloy is made as follows. The vanadium slag, which is produced by blowing vanadium-containing cast iron in Bessemer converters, is crushed to a grain size of 0.5 to 30 mm, after which the manganese fraction of the vanadium slag is separated from the non-magnetic component by ring magnet separation. The granules of the fabric produced with a grain size of 0.5 to 30 mm, which are covered with a slag coating, are separated according to size and used for alloying cast iron, steel and alloys.

Best execution variants of the invention

1. Vanadium-containing steel or cast iron is melted in a charging furnace containing waste from this steel or cast iron in an arc furnace with a basic or acidic feed. A material in the form of granules with a grain size of 15 to 30 mm is used as the alloying material, the coating of which contains from 80 to 95% of the slag containing vanadium with the following composition in mass%: silicon oxide - 15 to 20; vanadium oxide - 16 to 20; Manganese oxide - 6 to 8; Titanium oxide - 3 to 6; Chromium oxide - 1 to 3; Calcium or magnesium oxide - 25 to 40; Iron oxide remainder and 5 to 20% of the metal component, which contains% by mass: carbon - 0.5 to 2.0; Vanadium - 0.01 to 0.05; Iron rest. The substance mentioned is placed in the furnace together with the feed material in an amount which makes it possible to reach the lower concentration limit of vanadium in the finished metal. After the charge had melted completely, the lime or oxidation slag was left to heat and the metal was heated, the slag was deoxidized with coke and ferrosilicon, after which the metal was additionally alloyed with vanadium, with the above-mentioned substance of the same composition, vanadium in an amount, based on its average content in the finished metal.

Analysis of the operating characteristics of the metal alloyed with the material mentioned, such as strength, thin liquid, impact strength, hardness, hardenability and related wear resistance, shows that the use of the alloy material allows the reliability and durability of castings made of steel or cast iron by 10 up to 30% compared to the castings which are alloyed with the known alloying substances, and the costs for alloying with vanadium are reduced by 50 to 100%. The utilization of the vanadium from the alloying material by the metal is from 85 to 88%.

2. Similarly, steel or cast iron is melted in an electric arc furnace using a slag metal material in the form of granules with a grain size of 15 to 30 mm, which contains 5 to 30% of the slag component of the same composition as in the first variant, and contains from 70 to 95% of the metal component of the same composition. At the beginning, the feeder price for the feed is Oxidation period 100% vanadium is introduced into the metal together with the substance, which, in the case of melting without slagging, results in the transition from 85 to 87% vanadium which is introduced into the furnace into the metal and the increase in the reliability and longevity of the metal by 20 to 30% causes. The cost of manufacturing the alloyed metal is reduced by 50 to 100% compared to the metal alloyed with the known ferroalloys.

3. An alloy containing 35 to 45% vanadium and 1 to 25% silicon was melted in an arc furnace. Into the feed, which had 8 _2% vanadium pentoxide, lime, ferrosilicon and aluminum, 10 to 25% (based on the vanadin content in the feed) of the alloying material was introduced in the form of granules with a grain size of 15 to 30 mm, the contains from 70 to 95% of the slag component of the following composition in mass%: silicon oxide - 14 to 18; Vanadium oxide - 16 to 20; Manganese oxide - 6 to 8; Titanium oxide - 6 to 10; Chromium Oxide - 1 to 3; Calcium and (or) magnesium oxide - 30 to 50; Iron oxide residue and which has from 5 to 30% of the metal component of the following composition in mass%: carbon - 0.5 to 1.2, vanadium - 0.01 to 0.05 and iron residue.

The degree of extraction of the vanadium from the alloy according to the invention through the metal was 95.4%.

To better explain the present invention, concrete examples are given below which illustrate the use of the vanadium-containing alloy for alloying steel, cast iron and alloys with vanadium.

example 1

Carbon steel containing chromium and vanadium was melted in a remelting process in an industrial arc furnace with a basic lining. Man used a feed containing 80% wastes of a chromium-containing steel and 20% of a carbon-containing semi-product containing 2.6% carbon, 0.04% phosphorus, 0.023% sulfur and 0.06% vanadium and the balance iron. 5% lime and 2 to 3% firebrick were also introduced into the load. After the feed material had melted down, the surface of the metal, the mass% of 0.57 to 0.62 carbon; 0.018 to 0.021 phosphorus; Contains 0.015 to 0.020 vanadium, the alloying substance, which has a shape of granules with a grain size of 0.5 mm, at a temperature of 1520 to 1540 ° C. The metal component of the alloy contained% by mass; Carbon - 2.4, vanadium - 0.03, chromium - 0.03, manganese - 0.04, iron residue, and the slag component, in an amount of 95%, based on the weight of the granules, showed in bulk % on: silicon oxide - 10; Vanadium oxide - 25; Manganese oxide - 14; Titanium oxide - 10: chromium oxide - 4; Calcium oxide - 3; Iron oxide rest. The alloying substance is taken in an amount which is calculated on the introduction of vanadium, based on the average content (0.12%) of the vanadium in the finished steel. After an insignificant (10 to 15 minutes) "boiling over" of the bath, the slag was processed with ferrosilicon with a consumption of 2 to 5 kg / t. The degree of exhaustion of the vanadium was 88.4%, and the relative wear resistance of the steel produced compared to the same steel alloyed with ferrovanadium increased by 12% while the alloying cost was reduced by 80%.

Example 2

In an industrial baking oven with basic feed, the remelting process melted carbon-containing steel, which had chromium and vanadium, from a feed material that contained 70% of waste of the carbon-containing steel containing chromium, 20% from a carbon-containing semi-product, which contains 2.5% carbon, 0.03% phosphorus, 0.021% sulfur and 0.05% vanadium and the rest of iron, and consists of 10% steel scrap. 4.5% lime and 2% fireclay were also introduced into the load. After the feed material had been melted down, the alloying material was added in portions to the surface of the metal, which contained% by mass 0.54 carbon, 0.017% phosphorus, 0.019 sulfur and 0.02 vanadium, at a temperature of 1550 ^° C., which was in the form of Has granules with a grain size of 10 to 20 mm. In the alloying substance, the metal component had a mass percentage of: carbon - 3.2, vanadium - 0.03, chromium - 0.03, manganese - 0.05, iron remainder, and the slag component, which in an amount of 5% , based on the weight of the granule, had in mass%: silicon oxide - 18; Vanadium oxide - 14; Manganese oxide - 4; Titanium oxide - 3; Chromium oxide - 1; Calcium oxide - 50; Iron oxide residue. The alloying substance is taken in an amount calculated on the loading of the vanadium, based on the average age (0.12%) of the vanadium in the finished steel. After the bath had "boiled over", the slag was treated with granulated ferrosilicon for 15 to 20 minutes.

The degree of exhaustion of the vanadium was 87.2%, the relative wear resistance of the steel produced compared to the same steel alloyed with ferrovanadium increased by 14% while the alloying cost was reduced by 120%.

Example 3

In an industrial arc furnace with a basic lining, carbon-containing steel containing chromium and vanadium was melted using the remelting process. 75% of waste of a carbon steel containing chromium and 25% of a carbonaceous semi-product containing 2.7% carbon, 0.04% phosphorus, 0.020% sulfur and 0.05% vanadium were used in the feed contains. 5% lime and 2.5% fireclay were also introduced into the load. After the feed had melted down, the surface of the metal, which had a mass of 0.51 C; 0.02 P; 0.018 S and 0.02 V contains, at a temperature of 1570 ° C in portions, an alloying substance which is in the form of granules. with a grain size of 30 mm. In the alloy, the metal component had a mass%: carbon 2.9, vanadium 0.04, chromium 0.02, manganese 0.02, iron balance, and the slag component taken in an amount of 85 %, based on the weight of the granules, had in mass%: silicon oxide - 24; Vanadium oxide - 18; Manganese oxide - 6; Titanium oxide - 6; Chromium oxide - 3; Calcium oxide - 24 and iron oxide residue. The alloying substance is taken in an amount which is calculated on the loading of the vanadium, based on the average content (0.12%) of vanadium in the finished steel. After boiling over, the slag was processed for 10 to 15 minutes with ground ferrosilicon.

The degree of extraction of the vanadium was 87%, the relative wear resistance of the steel produced increased by 16% compared to the steel alloyed with ferrovanadium, while the alloying costs were reduced by 80%.

Example 4

The cast iron, which was alloyed with up to 0.5% vanadium, was melted in an induction furnace with acidic feed. Cast iron (60%) and rolled iron (40%) were used in the feed. The metal was heated to a temperature of 1500 to 1520 ° C., after which the alloying material was added to the cast iron surface in the form of granules with a grain size of 10 to 15 mm in portions, calculated on the average content of vanadium (0.45%). The metal component of the alloying material contained in mass%: coal _l enstoff- 3.1, vanadium - 0.03, chromium - traces, manganese - traces, iron radical, - -and the slag component of the alloy, which was taken in an amount of 90%, based on the weight of the granules, had in mass%: silicon oxide - 18; Vanadium oxide - 18; Manganese oxide - 6; Titanium oxide - 6; Chromium oxide - 3; Calcium oxide - 30; Iron oxide - rest.

After the slag was deoxidized with the ferrosilicon powder and after a holding time of 10 minutes, the metal was tapped. The degree of vanadium exhaustion was 86.2%; the relative wear resistance of the rolls alloyed with vanadium of the aforesaid material increased by 20% compared to the rolls alloyed with vanadium, and the cost of alloying with vanadium was reduced by 80%.

Example 5

An alloy was melted in an electric arc furnace, which comprised 35 to 45% vanadium and 5 to 25% silicon. In addition to the vanadium pentoxide, lime, broserilicon and aluminum, the alloying substance mentioned was also introduced into the loading goods in an amount of 20% (based on the vanadium content in the loading goods). The fabric was fed to the hearth of the furnace before loading the remaining feed. The fabric was in the form of granules with a grain size of 30 mm. The metal component of the alloy contained% by mass: carbon - 3.5, vanadium - 0.05, chromium and manganese traces, iron residue, and the slag component, in an amount of 50%, based on the weight of the granules % by mass contained: silicon oxide - 14; Vanadium oxide - 20; Manganese oxide - 6; Titanium oxide - 4; Chromium oxide - 3; Magnesium oxide - 20; calcium oxide - 22; Iron oxide - rest.

The degree of extraction of the vanadium through the metal from the fabric was 94.9%. The cost of alloying with vanadium was reduced by 40% compared to melting the alloy only with the use of vanadium pentoxide.

Industrial applicability

The present invention can be used in pyrometallurgical production for alloying cast iron, steel or alloys with vanadium as well as for producing products containing vanadium.

Claims (3)

1. Material for alloying a metal with vanadium, which has the form of granules which contain a metal component, characterized in that the metal component is coated with a coating of a slag component of the following composition in mass%:

the ratio between the metal component and the slag component in mass% is:

2. Material according to claim 1, characterized in that the metal component has the following composition in mass%:

where the metal is composed of vanadium, manganese and chrome. 3. Material according to claim 1 and 2, characterized in that the granules have a grain size of 0.5 to 30.0 mm.