EP0235291B1 - Method for obtaining vanadium slag - Google Patents

Abstract

The vanadium slag contains the following components in per cent by weight: vanadium oxide 16-30, silicon oxide 10-24, manganese oxide 6-14, chromium oxide 1-12, titanium oxide 6-14, calcium oxide 0.3-30.0, metallic iron 2-20, iron oxide as the balance and has the following mineral composition in per cent by weight: spinellid 40-70; glass 2-10; pyroxenes and olivines representing balance. The grains of spinellid have a regular geometric shape and measure 25-80 mum. The method of obtaining the vanadium slag of the composition mentioned provides for the use of vanadium cast iron containing, in per cent by weight: vanadium 0.35-0.90, carbon 3.8-4.8, silicon 0.05-0.35, manganese 0.12-0.35, titanium 0.07-0.38, chromium 0.03-0.42, phosphorus 0.02-0.10, copper 0.04-0.32, nickel 0.04-0.32, cobalt 0.001-0.12, iron being the balance. The above-named cast iron is blown through with a gaseous oxidizer, such as oxygen, at a blast intensity of 1.5-3.0 m3/t.min, at a temperature of the cast iron at the beginning of blowing from 1,180 to 1,300oC and at the end of blowing from 1,400 to 1,650oC and with a specific area of the bath surface equal to 0.13 to 0.30 m2/t.

Description

The invention relates to processes for producing vanadium slag by pouring vanadium pig iron into a converter, adding flux components, blowing said pig iron with gaseous oxidizing agent to produce steel and vanadium slag.

Vanadium slag, which is formed in the oxidation of vanadium-containing pig iron in converters or in other aggregates, is a starting product for the production of vanadium pentoxide, which is mainly used for the extraction of ferrovanadine and other alloys rich in vanadia.

Recently, the proportion of vanadium slag has increased significantly, which is used directly for the production of vanadium-alloyed metals such as cast iron, steel and alloys.

The chemical and mineralogical composition of the vanadium slag, depending on its intended use, places special demands on the slags that are used for further processing to vanadium pentoxide, in which there are optimal concentration ranges for each component of the slag (depending on the adopted processing scheme).

In the USSR, a technology for the production of various mixtures of vanadium slag in converters with downwind and oxygen bubbles, with oxygen inflation and combined fan wind has been developed and made industrially usable (SU-A-316 727, SU-A-531 861, SU-A-589 258).

Beimengungen (MgO, A)₂0₃, R₂0) Rest (N.P. Lyakishev und andere, Vanadin in der Schwarzmetallurgie, Verlag "Metallurgia", 1983, S. 36).The slag obtained contains, in% by mass:

Additions (MgO, A) ₂ 0 ₃ , R ₂ 0) rest (NP Lyakishev and others, Vanadin in Schwarzmetallurgie, Verlag "Metallurgia", 1983, p. 36).

However, this mixture is unusable. The need to change them is caused, among other things, by increasing the concentration of vandin, calcium, manganese and other oxides. Under these conditions, it is necessary to optimize the composition of the vanadium slag in order to achieve higher indicators of the application of vanadium.

A pyrometallurgical process for applying the vanadium from the titanium magnetite ores, which provides for the formation of vanadium slag in converters, is also known from China (Sokolova KN, Proizvodstvo i potreblenie vanadia za rubezhom, Bulletin des Inst ⁱ tuts "Chermetinformatsia", 1981, Issue 10, (894 ), Pp. 3 - 15). The Vandin slag, which, in mass%, 10 - 15 V ₂ 0s, 35. 45 FeO, 8 - 13.5 Ti02, 7.6 - 35.4 Si0 ₂ , 2.7 - 5.7 MnO, 0.9 - 1.5 CaO and is obtained from pig iron types, which, in mass% , 4.5 C, 0.37 V, 0.2 Si, 0.21 Mn, 0.05 P, 0.05 S, 0.12 Ti, but is extremely low in vanadium, and its further processing is with a significant consumption of reagents.

(Journal of the Iron and Steel Inst., April, 1970, S. 340).Also known is a process for producing vanadium slag by inflating oxygen in pig-iron vibrating pans, which, in mass%, 3.95 C, 1.10 V, 0.24 Si, 0.22 Ti, 0.22 Mn, 0, 08 P, 0.087 S, 0.29 Cr, 0.04 Cu, 0.4 Ni. The vanadium slag obtained contains, in% by mass:

(Journal of the Iron and Steel Inst., April, 1970, p. 340).

However, this addition of the slag is obviously not ideal for the extraction of vanadium pentoxide; the temperature conditions during its production (in a range from 1180 to 1270 ° C) do not allow to obtain sufficiently large (over 50 µm) spinellide grains in the slag, which are well suited for the oxidizing roasting of the slag.

The main indicator of the processes for fresh vanadium-containing pig iron with the formation of vanadium slag is the degree of vanadium discharge into the slag, which is derived from the relative amount of vanadium that has been converted from the pig iron into the slag, ie from the degree of slagging of vanadium , and the relative amount of vanadium recovered from the slag during the latter separates from the metal. The degree of slagging of vanadium, as long-term practice shows, is mainly determined by the temperature of metal at the end of the vanadium application and is 93.4 to 93.5%. A first value of the degree of slagging of vanadium relates to the process that became known from South Africa (see Joumal of the Iron and Steel Inst., April 1970, p. 340), in which the final temperature of the metal is at most 1300 ° C (more precisely 1270 ° C), and a second value relates to freshening, which was realized in converters with oxygen bubbles in the USSR, where the metal temperature at the end of the vanadium application reached 1370 ° C (see Smirnov LA. "Metallurgicheskaya pererabotka titanomagnetitovykh rud"; Swerdlovsk , Publisher of the institute "UraINll-chermet", volume No. 18, pp. 58 - 76).

A further increase in the pig iron temperature, for example to 1400 - 1420 ° C, leads to a reduction in the slagging of vanadium under the same process conditions, since the "remaining" concentration of vanadium in the end metal is already 0.06 to 0.08% (on average 0 , 07%) is increased and the degree of slagging drops to 85%, ie 15% of vanadium contained in the pig iron is lost.

This creates the problem of increasing the temperature at the end of the vanadium application, which must be achieved without reducing the vanadium slagging. The solution to this problem made it possible to improve the possibilities of fresh iron melting and to increase the quality of the slag produced. The other cause of the loss of vanadium in the production of vanadium slag arises from the separation of the vanadium slag from the metal at the end of the ironing in a converter. These losses depend on the composition under the same other conditions and reach at best 5% in the USSR and 8.6% in South Africa (references to the sources are the same).

The total losses in the best variant of the scheme used in the USSR, which provides for the production of vanadium slag in a converter, are 12.5%, in South Africa they are 16%.

In order to reduce the vanadium losses in the separation of the vanadium slag from the metal, it is proposed to retain them in the converter from previous melting for the next melting (magazine "Stal", No. 7, 1976, Moscow, Smirnov LA and other "Povyshenie effectivenessnosti peredela vanadlysoderzhashchikh chugunov" , Pp. 597 - 601). However, this method also does not eliminate the vanadium losses when the temperature of the metal increases at the end of the application of vanadium to 1400 ° C. and above.

The invention has for its object to develop a method for producing vanadium slag in the oxidation of vanadium-containing pig iron, in which it is possible to increase the yield of vanadium from pig iron and to increase the quality of the vanadium slag.

und das Verblasen von Roheisen mit einem Oxidationsmittel bei einer Durchsatzmenge von 1,5 bis 3,0 m³/t min, umgerechnet auf Sauerstoff, bei einer Temperatur von 1180 bis 1300°C am Anfang des Verblasens und bei 1400 - 1650°C am Ende des Verblasens und bei einer spezifischen Fläche des Badspiegels von 0,13 - 0,30 m²/t durchgeführt wird,This object is achieved in that a vanadium slag is generated which contains mineralogical constituents such as spinellide, glass, pyroxenes and olivines, the vanadium, silicon, manganese, titanium, iron, chromium and calcium oxides and granules of metallic iron have dissolved in this carbon, and which, according to the invention, is characterized in that pig iron of the following composition, in mass%, is used as the vanadium pig iron:

and the blowing of pig iron with an oxidizing agent at a throughput of 1.5 to 3.0 m ³ / t min, converted to oxygen, at a temperature of 1180 to 1300 ° C at the beginning of the blowing and at 1400 - 1650 ° C at At the end of the blowing and at a specific area of the bath level of 0.13 - 0.30 m ² / t,

und die folgende mineralogische Zusammensetzung, in Masse-%, hat:

wobei die Körner von Spinellid eine regelmäßige geometrische Form und eine Größe von 25 bis 80 µm aufweisen.the vanadium slag produced has the following chemical composition, in% by mass:

and has the following mineralogical composition, in mass%:

the grains of spinellid have a regular geometric shape and a size of 25 to 80 µm.

Nach einer weiteren besonderen Ausführungsform wird auf das Roheisen vor dessen Verblasen mit Oxidationsmittel ein schlackenbildendes Gemisch der folgenden Zusammensetzung, in Masse-%, aufgegeben:

Es ist weiterhin bevorzugt, in das Roheisen vor dessen Verblasen bezogen auf die Roheisenmasse Stahlschrott in einer Menge von 1 bis 4 % und nach 15 bis 25 der Zeit des Verblasens Zunder in einer Menge von 4,5 bis 6,0 % einzuführen.According to a special embodiment, the vanadium slag produced has the following chemical composition in mass%:

According to a further particular embodiment, a slag-forming mixture of the following composition, in mass%, is applied to the pig iron before it is blown with oxidizing agent:

It is further preferred to introduce steel scrap in an amount of 1 to 4% into the pig iron before it is blown, based on the pig iron mass, and in an amount of 4.5 to 6.0% after 15 to 25 times of the blasting.

Finally, it is also preferred that the basicity of the vanadium slag when blown be maintained in a range from 1.0 to 1.4 by introducing 60 to 70% calcium-containing additives.

• - eine höhere chemische Beständigkeit gegen die Erhöhung der Temperatur der Ausbringung von Vanadin, die das Erzielen eines hohen Grades der Verschlackung von Vanadin bei t ≥ 1400°C ermöglicht;
• - optimale Heterogenität der Schlackenschmelze, die Verluste an Vanadin bei der Abscheidung der Schlacke von dem Metall von höchstens 5 % ermöglicht;
• - sie ermöglicht Vanadinverluste bei der Vorbereitung der Schlacke für das Rösten (Zerkleinerung, Separation) von höchstens 5 %;
• - ein hoher Grad der Ausbringung von Vanadin aus der Schlacke nach dessen oxidierendem Rösten unter Zusatz bei Wasser- und (oder) Säureextrahierung von "Abbrand" im Herstellungsprozeß von Vanadinpentoxid;
• - eine effektive Legierung von Metall - Gußeisen, Stahl, Legierungen - durch Vanadin.

The solution according to the invention has the following advantages compared to the known ones:

• - a higher chemical resistance to the increase in the temperature of the application of vanadium, which enables the achievement of a high degree of slagging of vanadium at t ≥ 1400 ° C;
• - optimal heterogeneity of the slag melt, which enables losses of vanadium in the separation of the slag from the metal of at most 5%;
• - It allows vanadium losses in the preparation of the slag for roasting (crushing, separation) of at most 5%;
• a high degree of spreading of vanadium from the slag after its oxidizing roasting with the addition of water and (or) acid extraction of "burn-up" in the manufacturing process of vanadium pentoxide;
• - an effective alloy of metal - cast iron, steel, alloys - through vanadium.

An advantage of the preferred mixture of the vanadium slag according to claim 2 is that a combination of the oxides of alkali metals and the carbon leads to an improvement in the microstructure of slag. This increases the average size of the spinellide grain, which is the main vanadium-containing phase of the vanadium slag. Another effect of the combined action of these components is the maintenance of a porous microstructure of spinellide. The latter circumstance is very important since, due to the enlargement of the reaction area, the destruction of a spinellide grain in the oxidation-reduction reactions is facilitated and the formation of a new phase occurs not only on the periphery of a spinellid grain, but also in the pore size, which ultimately the intensification and the increase in the completeness of the application of Vandin to a finished product.

To increase the quality of the slag obtained, to reduce the consumption of molten pig iron and to increase the output of vanadium in the slag and the yield of metal at the end of the production process, it is advisable to proceed as explained in claim 3.

This process allows additional vanadium to be introduced into the slag.

In addition, it is expedient to work as described in claim 4 to further reduce the consumption of molten pig iron, to increase the concentration of vanadium oxide in the slag and to improve its microstructure.

To maintain the basicity of the vanadium slag from 1.0 to 1.4, which is mainly used for alloying with vanadium (directly from the slag) of cast iron, steels and alloys, 60 to 70% calcium-containing fluxes are introduced before the pig iron blowing.

To reduce the content of iron oxides in the vanadium slag after blowing pig iron with oxygen, the intermediate product or the steel is blown through with an inert gas.

Roheisen solcher Zusammensetzung wird in konventionellen Hochöfen erschmolzen, die meistenteils einen geringen Nutzraum (unter 1000 m³) haben, unter Bezugnahme auf jeweils bekannte Besonderheiten des Durchschmelzens von Titanomagnetiten, die durch Bildung von Titanoxicarbonitriden im Ofenherd hervorgerufen werden.Vanadium slag of the above composition is produced from vanadium pig iron by its oxidation with gaseous oxidizing agents. It was found that the above-mentioned composition of the slag is determined by the chemical composition of pig iron, which, according to the invention, as mentioned above, has the following composition, in mass%:

Pig iron of such a composition is smelted in conventional blast furnaces, which mostly have a small usable space (below 1000 m ³ ), with reference to the known peculiarities of the melting of titanium magnetites, which are caused by the formation of titanium oxycarbonitrides in the furnace.

A change in the amount of pig iron components, which exceeds the mentioned limits for only one of them, leads to undesirable consequences.

A reduction in the concentration of vanadium in pig iron below 0.35% reduces the concentration of vanadium oxide in the slag below 16% even with the lower limits of the other components, which makes it more difficult to process it into vanadium pentoxide. An increase in the concentration of vanadium in pig iron to over 0.90% is undesirable, however, because at this concentration of vanadium the resulting vanadium slag contains more than 30% vanadium oxide and thereby both the completeness of the slagging of vanadium and the completeness of the separation of the vanadium slag from Metal (due to thickening) decrease, which leads to increased vanadium losses.

The role of silicon and manganese dissolved in pig iron in the proposed amount is that during the oxidation together with the iron oxides they form a low-viscosity silicate component which is necessary for the formation and growth of the spinel-containing phase. A concentration of silicon in pig iron above 0.35 is undesirable because the concentration of vanadium oxides drops below the required level of 16 when the concentration of silicon in pig iron is above 0.35.

Similar causes also limit the permissible range of concentrations of manganese in pig iron.

Chromium and titanium contained in pig iron are completely converted into the complex spinellide in the stated range of concentrations by making it more chemically stable and high-melting. The increase in the chemical resistance of complex spinellids, in turn, contributes to more complete oxidation of vanadium in slag and to a reduction in the losses in the separation of the slag from the metal, which increases the yield of vanadium.

Copper, nickel and cobalt dissolved in pig iron, which increase the activity of carbon, act to increase the amount of oxygen consumed for the oxidation of iron and other slag-forming components, including vanadium , and thus indirectly contribute to increasing the intensity and completeness of the oxidation of vanadium and its discharge from pig iron into the slag.

The vanadium pig iron of the above composition is poured into a converter according to the invention and blown (oxidized) with a gaseous oxidizing agent, e.g. B. with oxygen at a throughput of 1.5 to 3.0 m ³ / t - min, at a temperature of pig iron at the beginning of the blowing from 1180 to 1300 ° C and at the end of the blowing from 1400 to 1650 ° C, and with a specific area of the bath level from 0.13 to 0.30 m ² / t.

These parameter parameters of the process ensure a complete and intensive stirring of iron-containing additives (coolants) and / or flux additives into the bath in order to intensify the vanadium oxidation and to obtain a vanadium slag of the required chemical, mineralogical and granulometric compositions, which bring about a necessary sorption capacity in relation to vanadium oxides: elimination of "dead zones" in the lower and near-metal layers; the normal "boiling down" of slag, which causes the reduction in the concentration of metal inclusions and free iron oxides and the increase in the size of the spindle spindle grain with the formation of optimal silicate skin on its circumference. These advantages significantly increase the effectiveness of processing the slag into vanadium pentoxide. It emphasizes that the parameter level according to the invention makes it possible to avoid a difference in vanadium content which is dependent on the bath depth, which also contributes to the passage of vanadium into the slag.

It should be emphasized that the main role in securing the effects mentioned is the connection of the specific area of the bath level with the intensity of the oxidant supply. Exceeding even one of the parameters with regard to the limits mentioned leads to undesirable sequelae. For example, the reduction in the specific surface area of the bath level to below 0.13 m ² / t brings about a considerable reduction in the degree of slagging of vanadium, particularly at t> 1330 ° C., and in the quality of the slag produced (enlargement of metal inclusions and free iron oxides , Reduction in the grain size of spinellide). However, increasing it to over 0.30 m ² / t also has a negative impact on the relevant indicators and leads to local deviations from the required content of both the slag and the metal.

The initial temperature of pig iron is also of great importance for the achievement of the task. Lowering the temperature to below 1180 ° C causes an undesirable considerable deterioration in the quality of the slag (enlargement of metal inclusions and iron oxides, reduction in the size of the spinellide grain). An increase in temperature to over 1300 ° C leads to a significant increase in the intensity of carbon burnout immediately at the start of the blowing process, which slows down the oxidation of vanadium and reduces its degree of slagging.

It is important that the method according to the invention ensures an extremely high degree of slagging of vanadium (over 90%) at temperatures (1400-1650 ° C.) which are significantly higher than in the known methods, in which the temperature at such a degree of slagging of vanadium usually does not exceed 1350 ° C °. The degree of slagging of vanadium is reduced to below 90% only at t> 1480 ° C, but this stabilizes at the level 85 - 90% at t - 1480 - 1600 ° C by further changing to the same values ( 90% and above) at t> 1600 ° C, where the "remaining" concentration of vanadium in the metal can drop to 0.01% at C <0.25%.

The rise in temperature of the metal at the end of the application of vanadium makes it possible, in comparison to the known processes, not only to improve the composition of the slag produced and to increase the application of vanadium at higher final temperatures of the application, but also significantly (to 25 to 30 t / min) to increase the throughput in steel production.

When carrying out the process, it is highly expedient to use a slag-forming mixture which contains the waste from vanadium-containing petroleum types, the masut, magnetic fraction of vanadium slag and mill scale and has the composition as mentioned above.

The essence of this addition is not only in the obvious increase in the amount of vanadium in the slag due to the transition from hydrocarbons and the magnetic fraction of the vanadium slag - the by-product of their preparation for oxidizing roasting when producing vanadium pentoxide, but also in the fact that heavy hydrocarbons, for example masut, which is introduced into the mixture according to the invention, binds particles of easily pourable materials - of scale and magnetic fraction of the vanadium slag - by contributing to the maintenance of a homogeneous mass, the particles of which adhere to one another, which practically eliminates their discharge during blowing and ensures effective use. In addition, the hydrocarbons contained in the mixture, by reacting with blower oxygen, develop an additional amount of heat by increasing the metal temperature and accelerating the melting and the interaction of the molten mixture with the metal. This makes it possible to increase the consumption of iron ore materials, for example scale, and to increase the degree of transition from vanadium from pig iron to commercially available slag.

The magnetic fraction of the vanadium slag which is introduced into the mixture and which is produced during the preparation (mechanical comminution, grinding and magnetic separation) of the vanadium slag for oxidizing roasting when pentoxide is produced also contributes to increasing these indicators. It represents metallic granules from 0.1 to 20 mm in size, on the surface of which are difficult to separate "burnt-in" particles of vanadium slag. Depending on the size of the granules, the degree of slagging of the granules is 20 to 50%. The homogeneous chemical composition of the magnetic fraction of the vanadium slag is, in mass%, as follows: 50 to 80 femetal; 2 to 6 VzOs; 1 to 3 MnO; 2 to 8 Si0 ₂ ; 1 to 3 T'i0 ₂ ; 5 to 20 Fe (in oxides); 0.03 to 0.05 P; 0.02 to 0.03 S; 0.1 to 2.0 C.

The use of the magnetic fraction mentioned also creates the following advantages. As a result of a greater density (than in the case of scale), it contributes to more intensive stirring of the slag-forming mixture into the metal when it is blown.

Exceeding the limits of the content of the mixture of main components leads to undesirable consequences. With the hydrocarbon content below 0.5% there is a slight "wetting effect" and when the concentration is above 6% there is a noticeable overheating of the slag, which has a negative effect, for example, on the stability of the lining of the converter.

The amount of magnetic fraction in vanadium slag in the mixture is limited by the time it is dissolved. With a content of more than 20%, it remains in the slag that forms, which means that its quality deteriorates. With a content of less than 5%, their presence in the mixture is almost inappropriate.

In order to further increase the slag quality, in particular to decrease its macro- and micro-inhomogeneity and to increase the concentration of vanadium oxides and reduce the consumption of molten pig iron, it is proposed, together with the iron ore, for example scale, a steel scrap in an amount of 1 to 4 Add% to be added before pouring the pig iron. Before the next addition of scale, which takes place after 15 - 25% of the time of blowing, an acidic thin slag is made, which slags the added scale well and reduces its removal and changes the mechanism of dissolution of scale, which is mainly due to the previous one Dissolution in silicate vanadium slag takes place, which leads overall to a reduction in the intensity of the metal spraying and the falling of metal drops into the slag and the amount of metal inclusions.

When using this method, however, the macro- and micro-inhomogeneity of the slag is significantly reduced, which is extremely important for their further use for the production of vanadium pentoxide.

version 1

Vanadium pig iron of the following composition, in mass%, is poured into a converter: 4.2-4.4 C; 0.10 - 0.20 Si; 0.40-0.60 V; 0.10-0.20 Ti; 0.10-0.20 Mn; 0.05 - 0.15 Cr; 0.03 - 0.06 P; 0.02 - 0.043 S; 0.08-0.12 Cu; 0.08 - 0.12 Ni; 0.001 - 0.12 Co. The amount of cast iron cast is intended to ensure that a specific area of the bath level is maintained in a range from 0.15 to 0.25 m / t.

in einer Menge von 40 bis 90 kg/t flüssiges Roheisen verwendet. Nach dem Aufgeben des Gemisches auf die Roheisenoberfläche beginnt man mit dem Sauerstoffblasen, wobei Sauerstoff mit einer Durchsatzmenge von 1,8 bis 2,2 m³/t - min zugeführt wird. Nach 7 bis 10 Minuten langem Blasen mit Sauerstoff, der von oben durch eine wassergekühlte Winddüse zugeführt wird, wird das Verblasen eingestellt, und das Metall enthält bei einer Temperatur von 1420 bis 1420°C, in Masse-%: 2,4 - 2,8 C; Si - Spuren; Ti - Spuren; 0,02 - 0, 04 V; 0,03 - 0,06 P; 0,02 - 0,04 S; 0,08 - 0,12 Cu; 0,04 - 0,12 Ni; 0,001 - 0,11 Co.The temperature of the pig iron after pouring it into the converter is 1270 to 1280 ° C. For slag making, a slag-forming mixture containing, in mass%:

used in an amount of 40 to 90 kg / t liquid pig iron. After the mixture has been applied to the surface of the pig iron, oxygen blowing begins, oxygen being supplied at a throughput of 1.8 to 2.2 m ³ / t-min. After blowing for 7 to 10 minutes with oxygen, which is supplied from above through a water-cooled wind nozzle, the blowing is stopped and the metal contains at a temperature of 1420 to 1420 ° C., in% by mass: 2.4-2, 8 C; Si traces; Ti traces; 0.02-0.04 V; 0.03 - 0.06 P; 0.02 - 0.04 S; 0.08-0.12 Cu; 0.04 - 0.12 Ni; 0.001 - 0.11 Co.

The metal intermediate obtained is poured into a pan through the drain opening and the vanadium slag is left in the converter.

Then the cycle repeats, and after oxygen inflation is complete, the slag is blown with argon or other inert gas from above or below for 1.0-2.0 minutes. The metal contains after this melting, in mass%: 2.0 - 2.4 C; 0.030 - 04 V; 0.02 - 0.06 P; 0.02 - 0.035 S and has a temperature of 1420 to 1450 ° C.

und weist dabei die folgende mineralogische Zusammensetzung, in Masse-%, auf:

Die Körner vom Vanadinspinellid kristallisieren in Form regelmäßiger geometrischer Körper, ihre Größe beträgt 30 bis 60 µm.The mass of vanadium slag generated after pouring the metal, which is stored by two melts, contains:

and has the following mineralogical composition, in mass%:

The vanadium spinellide grains crystallize in the form of regular geometric bodies, their size is 30 to 60 µm.

Variant II

Pig iron of the same composition as described in variant 1 is blown with oxygen in the same converter. The starting parameters were the same, except that before the casting of pig iron into the converter, steel scrap in an amount of 40 to 50 kg / t of pig iron and after 20% (4 - 5 min) of the time of blowing scale, in an amount from 50 to 60 kg / t was used. After 20-25 minutes of oxygen blowing, during which the oxygen is supplied at a flow rate of 2.2-2.8 m ³ / t · min from above through a wind nozzle, the blowing is stopped and the metal, which has a temperature of 1600 to 1650 ° C, contains, in% by mass: 0.05 - 0.25 C; 0.01-0.03 V; 0.03 - 0.06 P; 0.02 - 0.03 p.

After casting, the metal produced is treated with slag-forming mixtures and cast or used for steel production in an SM furnace instead of the pig iron.

und weist dabei die folgende mineralogische Zusammensetzung auf, in Masse-%:

wobei die Körner von Vanadinspinellid, die eine regelmäßige geometrische Form aufweisen, eine Größe von 40 bis 80 µm haben.The slag produced according to this variant contains, in mass%:

and has the following mineralogical composition, in mass%:

the grains of vanadium spinellide, which have a regular geometric shape, have a size of 40 to 80 µm.

Vanadium slags which are produced according to the named variants are successfully processed to vanadium pentoxide, whereby they ensure high indicators for the application of vanadium to finished products, while the known vanadium slags are significantly more difficult to process.

To better understand the foregoing invention, concrete examples are given below which illustrate the production of vanadium slag of various compositions.

example 1

84 t of pig iron was poured into a converter, which, in mass%, contains: 3.8 C; 0.35 Si; 0.35 V; 0.07 Ti; 0.12 Mn; 0.03 Cr; 0.02 P; 0.04 Ni; 0.001 Co. The pig iron temperature after pouring into the converter was 1300 ° C.

Then, in the converter, an amount of 40 kg / t of slag-forming mixture (coolant) was introduced, which in mass% has: heavy hydrocarbons - 6 (2.4 kg / t). Magnetic fraction of vanadium slag - ₂₀ ( ₈ kg / t) scale - 74 (29.6 kg / t).

The flow rate of the oxygen to be blown up from the top was 3 m3 / t · min, and the specific area of the liquid metal level was 0.3 m ³ / t.

After the blowing was finished, the metal temperature was 1460 ° C, and the content thereof was in% by mass: 2.6 C; Si traces; 0.012 V; Ti traces; 0.01 Mn; Cr traces; 0.02 P; 0.04 Cu; 0.04 Ni; 0.001 Co.

The metal produced was poured into a pan and the slag was left entirely in the converter. Pig iron of the same composition and in the same amount was then poured into the converter. The consumption of coolant and oxygen remained the same.

Upon completion of the blowing, the metal contained, in% by mass: 2.5 C; 0.018 V; Si traces; Ti traces; 0.01 Mn; Cr traces; 0.02 P; 0.0% Cu; 0.04 Ni; 0.001 Co and had a temperature of 1450 ° C.

The slag formed, which had been stored by two melts, contained, in mass%: vanadium oxide - 16; Silicon oxide - 24; Manganese oxide - 6; Chromium oxide - 1; Titanium oxide - 6; Calcium oxide - 0.3; Metallic iron granules - 8; Iron oxide - rest.

Their mineralogical composition was as follows, in mass%: Spinellid - 40; Glass - 2: Pyroxenes and Olivine - 58. The grain size of the vanadium spinellide was predominantly 25 to 35 µm, with the grains having a regular geometric shape.

The degree of slagging of vanadium was 95%.

The degree of separation of the vanadium slag from the metal was 95%. The output of vanadium from the pig iron in the slag is 90.2%.

Example 2

200 t of vanadium pig iron were poured into a converter, which contains, in% by mass: 4.2 C; 0.21 Si; 0.46 V; 0.18 Ti; 0.22 Mn; 0.08 Cr; 0.06 P; 0.14 Cu; 0.16 Ni; 0.06 Co. The temperature of the pig iron was 1280 ° C.

Then slag-forming mixture in an amount of 50 kg / t, containing, in mass%, heavy hydrocarbons - 0.5 (0.25 kg / t) was added to the converter. Magnetic fraction of vanadium slag - 5.0 (2.5 krt), mill scale - 94.5 (47.25 kglt), used.

The flow rate of the oxygen supplied from above is 2 m ³ / t - min, and the specific area of the level of the liquid metal is equal to 0.13 m ³ / t.

After the blowing was finished, the metal temperature was 1400 ° C and the vanadium and carbon content was 0.028 and 2.8%, respectively.

The metal produced was poured into a pan and the slag was left entirely in the converter for the next melting.

Another melt, which was carried out with the same starting parameters, gave metal with a temperature of 1410 ° C. and a content of vanadium and carbon of 0.026 and 2.7%, respectively.

The slag produced, stored by two smeltings, contains, in mass%: vanadium oxide - 20.4; Silicon oxide - 14.2; Manganese oxide - 10.4; Cromoxide - 2.4; Titanium oxide - 8.6; Calcium oxide - 1.5; Metallic iron granules 10.2; Iron oxide - rest.

Their mineralogical composition is as follows, in mass%: Spinellid - 55; Glass - 5; Olivine and Pyroxene - 40. The grain size of vanadium spinellide - 30 to 40 µm. The grains are well crystallized and have a regular geometric shape.

The degree of slagging of vanadium is 94.3%.

The degree of separation of the vanadium slag from the metal is 93%. The yield of vanadium from the pig iron in the slag is thus 87.5%.

Example 3

22 t of vanadium pig iron was poured into a converter, which contains, in% by mass: 4.8 C; 0.90 V; 0.05 Si; 0.15 Mn; 0.18 Ti; 0.42 Cr; 0.10 P: 0.32 Cu; 0.32 Ni; 0.12 Co the temperature of the pig iron after pouring into the converter was 1180 ° C. Before casting pig iron, agglomerate containing vanadium was used in an amount of 106 kg / t in the converter. The specific area of the bath level was 0.24 m ² / t. The throughput quantity of the oxygen supplied through the tube-in-tube nozzles from below was 2.5 m3 / t · min. The consumption of natural gas for the nozzle protection was 10% of the oxygen consumption during the entire blowing process. After the blowing was finished, the metal temperature was 1420 ° C and the metal content of vanadium and carbon, in mass%, 0.05 and 2.8, respectively.

The metal obtained was poured off and the slag was partially left in the converter for the next smelting.

Other melts, which had the same initial parameters, gave metal with a temperature of 1430 ° C. and the same content of vanadium and carbon.

The slag formed, stored by the two melts (one only partially), contained in mass%: vanadium oxide - 30; Silicon Oxide - 10: Manganese Oxide - 0.4; Titanium oxide - 7.4; Chromium oxide - 12; Calcium oxide - 2.1; Granules of metal iron - 6.2; Alkali metal oxide - 9.0; Carbon - 0.1; Iron oxide - rest.

It had the following mineralogical composition, in mass%: Spinellid - 70; Glass - 10; Pyroxene and Olivine - 20. The vanadium spinellide grains were predominantly 30 to 50 µm in size and had a regular geometric shape.

The degree of slagging of vanadium was 95%. The degree of slag deposition from metal was 97%. The output from the pig iron in the slag was 92%.

Example 4

22 tons of vanadium iron were poured into a converter, which had the following composition, in mass%: 4.4 C; 0.52 V; 0.08 Si; 0.27 Mn; 0.32 Ti; 0.42 Cr; 0.06 P; 0.07 Cu; 0.21 Ni; 0.06 Co, the temperature of the pig iron was 1240 ° C.

Before pouring the pig iron, vanadium-containing agglomerate in an amount of 92 kg / t was used in the converter. The specific area of the bath level was equal to 0.24 m ² / t. The flow rate of the air supplied from below (converted to oxygen) was 3 m ² / t · min.

After the blowing was finished, the temperature of the metal was 1410 ° C, and its content of vanadium and carbon was in mass%, 0.03 and 2.6, respectively.

The metal produced was poured off and the slag was left entirely in the converter for the next smelting.

In two subsequent smeltings, which were carried out with the storage of slag with the same parameters, the content of vanadium and carbon in the metal is at a level of 0.03 and 2.6%, respectively.

The vanadium slag, stored from three melts, contained, in mass%: vanadium oxide - 16.6; Silicon Oxide - 12: Manganese Oxide - 10; Chromium oxide - 12; Titanium oxide - 14; Alkali metal oxides - 1.5: calcium oxide - 0.8; Carbon - 2.0; Granules of metal iron - 20; Iron oxide - rest.

Their mineralogical composition was as follows, in mass%: spinellide - 70; Glass - 8; Olivine and Pyroxene - 22. The Spinellid grains were 25 to 45 µm in size and had a regular geometric shape. The degree of slagging of vanadium was 93.4%. The application of vanadium in the slag - 89.5%.

Example 5

162 t of vanadium pig iron was poured into a converter, which contains, in% by mass: 0.52 V; 4.4 C; 0.14 Si; 0.18 Mn; 0.18 Ti; 0.03 Cr; 0.04 P; 0.12 Cu; 0.18 Ni; 0.005 Co. The temperature of the pig iron in the converter was 1280 ° C.

Slag-forming mixture of the following composition, in mass%, was applied to the surface of the pig iron: heavy hydrocarbons - 4.2; Magnetic fraction of vanadium slag - 15; Tinder - rest. The consumption of the mixture was 62 kg / t. The flow rate of oxygen blown onto the surface of the metal from above through a water-cooled nozzle was 1.5 m ³ / t. The specific area of the bath level was 0.18 m ² / t.

The metal had a temperature of 1470 ° C after the completion of the blowing, and the vanadium and carbon content in the metal was 0.03 and 2.2%, respectively, after the vanadium application was completed.

The metal was poured off and the slag was left entirely in the converter, after which the cycle was repeated with the same initial parameters. The metal temperature during the second melting was 1480 ° C with the same vanadium content. The carbon content was reduced to 2.1%.

The slag collected after the second melting contained, in mass%: vanadium oxide - 25.6; Silicon oxide - 14.1; Manganese oxide - 8.4; Titanium oxide - 8.5; Chromium oxide - 1.4; Calcium oxide - 3.0; Alkali metal oxide - 2.1; Koh lenstoff 0.5; Granules of metal iron - 8.4; Iron oxide - rest.

The mineralogical composition of the slag produced is as follows, in% by mass: spinellide - 60; Glass - 4; Pyroxene and Olivine - 36. Spinellid's grains were 40 to 60 µm in size. They form crystals in the form of regular geometric bodies.

Example 6

162 t of pig iron of the same composition as in Example 5 were poured into a converter. The temperature of the pig iron was 1275 ° C. Before this, 6.5 t (4%) steel scrap was introduced into the converter.

The flow rate of the oxygen blown from above was 2.5 m ³ / t - min, and the specific area of the bath level was equal to 0.18 m ² / t.

After 6 minutes (25% of the time of blowing), 7.2 tons (4.5%) of scale was applied to the metal surface and blowing continued at the same intensity.

At the end of the blowing, the metal contained 0.12% C and 0.01% V at a temperature of 1650 ° C. The degree of slagging in this variant was 98%. The slag contained, in mass%; Vanadium oxide - 28.4; Silicon oxide - 18.1; Manganese oxide - 8.2; Titanium oxide - 10.8; Chromium oxide - 2.3; Calcium oxide - 1.4; Granules of metal iron - 3.2; Iron oxide - the rest. The mineralogical composition of the slag remained the same, the grain of spinellide with extremely regular, clearly defined areas increased to 80 µm in size. After partially leaving the slag and repeating the operation with the same parameters, the slag content in the subsequent smelting remained practically the same as the former.

Example 7

162 t of pig iron of the same composition as in Examples 5 and 6 were poured into a converter. The hot metal temperature was 1275 ° C. Before that, an additive consisting of 1.6 t (1%) steel scrap was introduced into the converter.

The flow rate of the oxygen supplied from above was 2.5 m ³ / t - min, and the specific area of the bath level was equal to 0.20 m ² / t.

After 3 minutes (15% of the time of blowing), 9.6 tons of scale (6%) was added and blowing continued.

Upon completion of the blowing, the metal contained 0.62% C and 0.04% V at a temperature of 1580 ° C. The degree of slagging of vanadium was 92.4%. The slag contained, in% by mass: vanadium oxide 27.8: silicon oxide 17.4; Manganese oxide 8.0: titanium oxide 9.2; Chromium oxide 3.1; Calcium oxide 1.6; Granules of metal iron 3.6; Iron oxide - rest.

The mineralogical composition of the slag remained the same, the size of the spinellide grain of a regular shape was 60 - 80 µm.

After two cycles of slag storage, the indicators for the quality of slag did not change.

Example 8

160 t of vanadium pig iron of the previous composition and at the same temperature as in Example 7 were poured into a converter. Previously, 20 t of steel scrap and 1.4 t (60% of the total amount for a smelting) of lime used for the smelting were used. The blowing was carried out with a throughput of 3.0 m / t min and with a specific area of the bath level of 0.20 m ³ / t. After the blowing has ended at t = 1620 ° C., the metal contains 0.28% C, 0.04 V and 0.026% P. The slag contains, in% by mass: 20.2 vanadium oxide; 18.1 calcium oxide; 17.9 silicon oxide; Granules of metal iron - 2.0; Ti, Cr, Fe-oxide - rest. The basicity of slag - 1.0. The degree of slagging of vanadium - 92.5%. Slag is partially left behind for the next smelting.

Example 9

With the same parameters as described in Examples 7 and 8, the production of vanadium slag with a basicity of 1.4 is ensured by adding 1.6 t of lime (70% of the total consumption per smelting) together with scrap. A slag is obtained which, in% by mass, contains: 18.2 vanadioxide; 30 calcium oxide; 15 silicon oxide: 10 manganese oxide; 2.1 chromium oxide; 9.6 titanium oxide; 2.0 granules of metal iron; -Rest - iron oxide. The degree of slagging of vanadium is -92.5% at the end of the process and at a temperature of 1600 ° C.

Example 10

In a converter, 20 t of pig iron of the composition as in Example 7 with oxygen from above at a Blow throughput of 1 m ³ / t min and from below (2 m ³ / t min) through nozzles "pipe in pipe" at a specific area of the bath level 0.3 m ³ / t. Before casting pig iron, scrap (10% of the pig iron mass) and limestone (65% of the total amount for a smelting) were used in the converter.

After the blowing was finished, the basicity of the slag was 1.2 under the following ratio of the components in the slag, in mass%: 30 calcium oxide; 25 silicon oxide; 17.4 vanadium oxide; 18.4 Mn, Cr and Ti oxides; 2.0 granules of iron; Iron oxide - rest.

The metal has a temperature of 1620 ° C and contains 0.44% C, 0.04% V, 0.028% P.

Example 11

20 t of pig iron of the same composition and temperature as in Example 7 were poured into a converter. The blowing was carried out with a throughput of 3 m ³ / t-min with a specific area of the bath level of 0.3 _m ² _/ t.

When the metal reached 0.3% C at t - 1600 ° C, the blowing was stopped and then the metal was blown with argon bottom wind with a throughput of 0.2 m ² tt - min within 2 min. The vanadium content in the metal was 0.04% after completion of the blowing with oxygen, and after blowing the metal with argon at C - 0.25%, the vanading content in the metal increased to 0.05%.

Before blowing with argon, the vanadium slag was, in% by mass: 24.8 vanadium oxide; 14.2 silicon oxide; 3.6 granules of iron; 6.2 calcium oxide; 24.2 iron oxide; the rest is formed by Mn, Cr, Ti oxides.

After blowing with argon, the slag contained, in% by mass: 26.8 vanadium oxide; 14.1 silicon oxide; 3.8 granules of iron; 6.4 calcium oxide; 18.6 iron oxide; Mn, Cr, Ti-oxide - rest. The degree of slagging of vanadium was 89.5%.

The present invention may be in the ferrous metallurgy in the processing of T ^r tanomagnetiterzen metallurgical route under application of iron and vanadium are used.

The vanadium-containing blast furnace iron produced in this titanium magnetite processing scheme is subjected to oxidative blowing in converters to produce vanadium slag of the required chemical, mineralogical and granulometric compositions. The process according to the invention makes it possible to improve the quality of the vanadium slag, which can be used not only for the production of vanadium pentoxide but also as an alloy component for the direct alloying of cast iron, steel and alloys with vanadium.

The process is simple in terms of apparatus design and can be successfully used in existing converter halls that process pig iron containing vanadium.

Its use and the use of slags of the proposed compositions bring considerable savings to reactants.

Claims (5)

1. A process for the production of vanadium slag by pouring vanadium pig-iron into a converter, adding flux components, bessemerizing the said pig-iron with a gaseous oxidizing agent to produce steel and vanadium slag, characterized in that pig-iron of the following composition in mass % is used as vanadium pig-iron:

and the bessemerization of pig-iron with an oxidizing agent is performed with a throughput quantity of from 15 to 30 m³/t min, calculated on oxygen, at a temperature of from 1180 to 1300°C at the beginning of bessemerization and at from 1400 to 1650°C at the end of bessemerization and with a specific area of the bath level of from 0.13 to 0.30 m²/t,

the vanadium slag produced having the following chemical composition in mass %:

and having the following mineral composition in mass %:

the grains of spinel having a regular geometrical shape and a size of 25 to 80 µm.

2. A process according to Claim 1, the vanadium slag produced having the following chemical composition in mass %:

3. A process according to Claim 1, characterized in that a slag-forming mixture having the following composition in mass %:

is added to the pig-iron before its bessemerization with oxidation agent.

4. A process according to Claim 1, characterized in that steel scrap in a quantity of from 1 to 4 % is introduced into the pig-iron relative to the mass of the pig-iron before the bessemerization thereof and iron scale in a quantity of from 4.5 to 6.0 % is introduced after 15 to 25 minutes of the period of bessemerization.

5. A process according to Claim 1, characterized in that during bessemerization the basicity of the vanadium slag is maintained in a range of 1.0 to 1.4 by the introduction of from 60 to 70 % of calcium-containing additives.