RU2299921C2 - Method of producing complex foundry alloys from converter vanadium slag - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to processing converter vanadium slag into iron and complex foundry alloy. Reduction of vanadium, silicon, manganese, titanium, chromium, and iron from oxides of converter vanadium slag is conducted on supports formed in two smelting assemblies. In the first smelting assembly, iron and a portion of vanadium are silicon-reduced on iron-containing support, with which the metals are smelted together. Once major part of iron from a batch of converter vanadium slag is reduced, this portion is tapped out of first smelting assembly. Iron-depleted converter vanadium slag is then transferred to the second smelting assembly, wherein, first on support of titanium-containing complex foundry alloy, vanadium, silicon, manganese, chromium, and iron are titanium-reduced from their oxides contained in iron-depleted converter vanadium slag at support temperature 1700° C and specified calcium oxide supply to form titanium-free complex foundry alloy and slag containing titanium and calcium oxides. Titanium-free complex foundry alloy is tapped out of smelting assembly in amount up to 70% and titanium is aluminum-reduced from slag using, as support, not tapped rest of foundry alloy to form complex titanium-containing foundry alloy containing metals from iron-depleted portion of converter vanadium slag. Final slag is tapped out of second smelting assembly.

EFFECT: increased vanadium content in final produce, reduced power consumption during converter vanadium slag processing, increased content of titanium in foundry alloy to 70%, and avoided emission of gas, which would require additionally treatment equipment.

10 cl

Description

The invention relates to metallurgy, in particular to the production of complex alloys from converter vanadium slag (KVSh).

At present, the bulk of CFW in Russia is obtained from blast-furnace vanadium-containing cast iron at the Nizhne-Tagilsky Metallurgical Plant (NTMK) and at the Chusovsky Metallurgical Plant (ChMZ).

The mixture entering the NTMK and ChMZ blast furnaces includes a concentrate prepared for smelting obtained from ore from the Kachkanarsky deposit. In the concentrate, in addition to the main element - iron, contains valuable elements such as vanadium V and titanium Ti. After remelting the charge in the blast furnace, most of V goes to cast iron, most of Ti to blast furnace slag (LH).

Vanadium from cast iron is first transferred to KVS, which is further processed depending on what they want to produce from it: pigment, pure vanadium, ferrovanadium, complex ligatures containing V, Ti, Mn, Si, Cr, Fe, etc. d.

The main part of the obtained HSS is spent to obtain a product containing V, and such a valuable metal as Ti is actually lost.

KVSh NTMK has the following chemical composition,%: 18-19 V ₂ O ₅ ; 17-18 SiO ₂ ; 9-10 MnO; 8-9 TiO ₂ ; 26-32 Fe; 2-3 Cr ₂ O ₃ ; 1-3 CaO; 0.03-0.05 P; 9-11 metal inclusions [1, p. 54]. Each ton of such KVSh is on average contained, kg: V - 103.67; Ti - 51.00; Mn 73.60; Si 81.68; Cr -1.57; the rest is mainly Fe and oxygen.

Known carbothermal, metallothermic (silicothermic and aluminothermic) and combined methods for the production of vanadium-containing ligatures from KVSh [2, p. 81].

In the carbothermal process, a considerable amount of quartzite has to be deposited in the charge (approximately as much as the HSS is deposited), otherwise an undesirable formation of titanium and vanadium carbides occurs.

The silicothermal method noted above has no drawbacks, but if we compare the main technical and economic indicators of the production of silicovanadium [2, p. 83, table 2.11] with carbothermic and silicothermic methods, the silicothermic method has no great advantages, especially for the extraction of elements into the alloy .

The main disadvantage of the aluminothermic method for producing ligatures is the high cost of the reducing agent (aluminum), since aluminum by this method reduces metals from oxides, which are much cheaper than iron and silicon.

The situation with economic indicators can change for the better if you use the combined method, in which first deplete the KHS in iron using the silicothermal method of reducing iron from oxides, and then recover other metals from KFS oxides using the aluminothermic method.

Studies on the preparation of complex master alloys from KVS, preliminarily depleted in iron and enriched in vanadium, were previously carried out in Russia by remelting KVS in an electric furnace under poorly reducing conditions, but this did not come to industrial introduction. The reason for this is the lack of an acceptable special melting unit [2, p. 84-85].

The prior art also knows the technology of liquid-phase reduction of oxides from a charge, which is suitable for the reduction of oxides from converter vanadium slag, which includes the melting of a portion of a CVH in a parabolic well formed by the electromagnetic field rotation of a liquid metal substrate, the reduction of the CVC oxides with a reducing agent, and the alloying of reduced metals with a substrate, separate plums of metal and slag phases [3].

According to the method adopted for the prototype, efficiently selective extraction of one or two metals from slag, for example, complete extraction of iron and most of vanadium from iron-vanadium-containing slag, is effective. If Ti, Mn, Si, Cr are to be extracted from the slag, for example from the water-heat transfer unit, in addition to Fe and V, it will be difficult to extract them using the method adopted as the prototype in complex ligatures, in particular, because it is difficult to provide the necessary conditions reduction of metals from various KVSh oxides.

The novelty of the proposed method lies in the fact that the recovery of vanadium, silicon, manganese, titanium, chromium, iron from KVS oxides is carried out on substrates formed in two melting units (PA), and in the first PA on an iron-containing substrate, the temperature of which is maintained at 1550 -1600 ° C, silicon reduces iron and part of vanadium, which is then fused to the substrate, and after a large portion is recovered from a portion of KVS, this part is removed from the first PA, while the remaining iron-containing sub the cells from the first PA completely merge the KSH depleted in iron and transfer it to the second PA, where first on the substrate from a titanium-containing complex ligature at a substrate temperature of up to 1700 ° C and the regulated supply of calcium oxide to it, titanium is reduced from vanadium, silicon depleted in KB1P, silicon, manganese, chromium and iron from their oxides to obtain a complex ligature that does not contain titanium, and varnish containing oxides of titanium and calcium, the resulting complex ligature that does not contain titanium, in an amount up to 70% is drained from PA, from slag a titanium is reduced with yuminium using a complex ligature remaining in the PA not containing titanium as a substrate, the temperature of which is increased to 1800-1900 ° C, reduced titanium is alloyed with the remaining part of the non-fused ligature to obtain a complex titanium-containing ligature containing metals from an iron-depleted portion of KVSh , and the final slag is drained from the second PA.

Iron oxide is recommended to be restored with silicon, not allowing it to decrease in slag less than 5-6%.

It is advisable to introduce silicon in a mixture with KVS, respectively, with a given oxide content in KVS depleted in iron and not in pure form, but as part of ferrosilicon.

In some cases, after draining the KVS depleted in iron, it is advisable to solidify, grind it and transfer it to the second PA in this form.

It is recommended that enrichment of iron-fired KBC with titanium oxide in the second PA be carried out by adding ilmenite and, in particular, fermented ilmenite to 80-90%, as well as by adding rutile.

The reduction of titanium from oxide is recommended to be performed with aluminum from a ferroaluminium alloy, while the iron freed from aluminum is fused with the resulting titanium-containing alloy.

When transferring iron-deficient KV1P to the second PA, it is enriched with titanium oxide.

The recommendation to use silicon as the reducing agent in the first PA makes it possible to mainly reduce iron oxides from all KHS oxides, since other metals in KVS have more free energy of oxide formation reactions than iron (iron has less affinity for oxygen). This does not mean, however, that other KVS oxides to some extent cannot be reduced simultaneously with iron oxides. In particular, if vanadium oxide is present in the slag melt, part of it can also be reduced to vanadium, moreover, the less iron oxide remains in the slag, the more vanadium will be reduced. The above is clearly confirmed in the source of information [1, p. 216-220, table 5.4].

Considering the data provided in the information source, we can say that if the substrate temperature in the 1st PA is about 1600 ° C and 4-6% of iron oxides remain unreduced in the slag phase, then in the 1st PA there will be practically no KWH to recover Ti, Mn and Si from their oxides. Vanadium oxide at this iron oxide content will be partially reduced, but its reduction will be in the range of 10-15%.

Silicon for the reduction of iron from oxides is recommended to be introduced not in its pure form, but in the form of ferrosilicon, for example, ferrosilicon grades FS45, FS65, FS75. The cost of silicon in ferrosilicon is less than pure silicon. The specific gravity of ferrosilicon (FS45. FS65) is greater than the specific gravity of the slag melt, which allows it to immerse well in the slag melt and effectively deoxidize iron oxides.

The recommendation to have a titanium-containing ligature substrate in the 2nd PA makes it possible to obtain two complex ligatures from KSS depleted in iron, one without titanium, and the second titanium-containing, with a high titanium content if desired.

Ligature without titanium is obtained because, after draining the iron-depleted HFS on a substrate with titanium, almost all of the titanium in this ligature can be consumed to reduce the oxides V, Mn, Si, Cr, and Fe. Metals recovered by titanium alloy with the substrate, resulting in the formation of a ligature without titanium, which in a specified amount should be drained from the 2nd PA, leaving the amount in PA that is required so that, after subsequent reduction of the titanium oxides that have gone into the slag, the aluminum is obtained ligature with a given titanium content. The less ligatures left without titanium in the 2nd PA, the more titanium will be in the titanium-containing ligature as a result of its reduction with aluminum. The amount of titanium-containing ligature can be significantly increased if ilmenite is added to the KVS supplied to the smelting. When ilmenite is added to the KVS, its iron oxide will be reduced in the 1st PA, and the titanium oxide of ilmenite, which will be transferred to the 2nd PA together with the KVS depleted in iron, in this PA will be reduced to titanium, and thereby increased titanium content in titanium-containing ligature.

The addition of ilmenite to KVS is also useful because it can compensate for the loss of titanium if all of the titanium oxide is not recovered and part of it goes into the final slag.

It is better to introduce ilmenite into the CFB ironic, for example, up to 80-90%. This will reduce the cost of an expensive reducing agent - aluminum.

The economic indicators for the production of complex ligatures increase even more if the addition to the KVSh will consist of rutile, because the cost of rutile is much less than the cost of titanium, which is restored from rutile.

It should be noted that if part of the titanium goes into the final slag during the processing of the KVS depleted in iron, it will not mean the loss of titanium. The final slag, containing up to 70-80% alumina, is not sent to the dump, it is better to extract alumina from it in a well-known manner. When extracting alumina, titanium will go into red mud (KS). When processing KS by the method [4], titanium oxide can be reduced to titanium and converted to a titanium-containing ligature.

In an example implementation of the method, the circuit shown in the drawing is implemented. As a melting unit, it is recommended to use a multifunctional melting unit (MPA), the design of which is protected by the patent of the Russian Federation No. 2207476 [5].

The example presents theoretical calculation data based on the processing of one ton of KVSh, the chemical composition of which is given above. The calculation results determine the effectiveness of the proposed method.

KVSh oxides by the method are reduced in two PA, silicon (in the 1st PA), titanium and aluminum (in the 2nd PA). However, titanium, as a reducing agent, is negotiable. During the processing of KVSh, a certain amount of it is spent on the reduction of individual KVSh oxides, but then titanium oxides obtained during the reduction are reduced by aluminum. It follows that the consumption for the reduction of metals from oxides is determined by the consumption of silicon in ferrosilicon in the 1st PA and the consumption of aluminum in ferroaluminium in the 2nd PA. But one must keep in mind the following. Although aluminum is consumed as a reducing agent only in the 2nd PA, its consumption indirectly extends to the oxides that are reduced in the 1st PA. The oxygen carrier from the 1st PA to the 2nd PA is silicon, which, after reduction in the 2nd PA, with titanium, replenishes the ligature without titanium with silicon.

In the case of incomplete reduction of oxides of titanium in iron-depleted KBS, which will entail a lack of titanium in the remainder of the titanium-containing ligature, this disadvantage should be compensated by the fact that a certain amount of ilmenite concentrate is fed into the 1st PA together with KVS.

The substrate in the 1st PA is created from liquid iron, which, before being fed into it, the HFS is spun by the electromagnetic field, with the aim of forming in it a hole of a parabolic shape of a given size. The temperature of the substrate should be at least 1600 ° C.

The energy for the melting of KVS and for the reduction of the KVS oxides comes from the crucible parts of the 1st and 2nd PAs, taking into account that the reaction of the reduction of oxides with silicon, titanium, and aluminum is exothermic, i.e. with the release of heat.

If 5-6% of iron oxide remains during the reduction of iron in the slag phase, then about 10% of vanadium from vanadium oxide will leave in the liquid iron substrate, which is confirmed by the data presented in Table 5.4 from the information source [1, p. 220].

Based on the foregoing, we accept the following conditions for the reduction of KVS oxides in the 1st and 2nd PA.

In the 1st PA, silicon will recover 94-95% iron oxide and 10% vanadium oxide, the remaining oxides will be reduced in the 2nd PA first with titanium and then with aluminum. 335 tons of iron oxide and 18.5 kg of vanadium oxide will be recovered from 1 ton of KVS, therefore, in the 1st PA. To restore the indicated amount of oxides, it will be necessary to use about 73 kg of silicon from ferrosilicon, and if FS75 ferrosilicon is used, then it should have about 100 kg. In this case, 285 kg of iron and 10 kg of vanadium will go into the iron-containing substrate.

It should be said that after processing the first predetermined portion of KVS from the 1st PA, the metal mass merges equal to the weight of reduced Fe and V from this portion. The percentage of vanadium in this mass will depend on what the weight of the original substrate was. The next portion of KVS with the addition of ferrosilicon will be fed onto a substrate in which, in addition to iron, there will be vanadium. It cannot be ruled out that the reduction of iron oxides in the next portion of the SHF will be carried out not only by silicon ferrosilicon, but also by vanadium from the substrate.

The consumption of aluminum during the processing of 1 ton of water-cooled water is determined by the amount of oxygen that is present in the water-carbon oxide oxides. The mass of oxygen in 1 t of KVSh is 321 kg. Such an amount of oxygen can oxidize 361 kg of aluminum.

Thus, if we compare the element-wise value of metal reducers of KVSh oxides — silicon and aluminum — and the element-wise value of metals in the resulting products, which mainly determines the economy in the proposed method, this comparison will look as follows.

In the appendix to the journal "Ural Metal Market", Nos. 3, 4 for 2005, prices for metal products were published. These prices are taken into account when calculating the cost of metals. The price of FS75 ferrosilicon is $ 1.2 per kg, the price of pig aluminum A5 - A8 grade is $ 2.0 per kg. The cost of reducing agents, therefore, will be: for FS75 ferrosilicon - $ 120, for aluminum - 642. In total - $ 762.

The element-wise total cost of metals in the products obtained from the processing of 1 ton of KVSh will be more than $ 3,000. The difference in value is more than $ 2,000. Profit from the manufactured metal products (vanadium-doped iron and two types of ligatures), however, it will be possible to determine if take into account other expenses and, first of all, the cost of the purchase of KVSh. It can be assumed that this expense and other expenses will not exceed $ 1,000. As a result, it can be argued that the profits from the processing of KVS by the proposed method will be in the range of 800-1000 dollars for each ton of processed KVS.

There will also be income from non-metallic products. The final slag is essentially a fused clinker in which the aluminum oxide content is up to 75%. Such clinker can be used to produce expensive high-alumina cement, costing up to $ 800 per ton, or it can be sent to an aluminum smelter, where alumina will be obtained from it.

When implementing the method provides for the use of two PA. However, one PA can be dispensed with if the KSH depleted in iron is not poured into the 2nd PA, but poured into a ladle, moved to the casting place, poured into small molds there, cooled, crushed, stored to a certain amount, and then in the same PA, recycle it into ligatures without titanium and with titanium according to the technology described above, but recycle CFW depleted in iron. At the initial stage of organizing the production of KVS processing, work with one PA is quite acceptable.

The technical result from the application of the proposed method is as follows.

When processing KVS, an increased vanadium content in the products is provided, since the main part of vanadium oxide is restored when KVS is depleted in iron.

Since the recovery of KVS oxides does not involve endothermic reactions (with heat absorption), but exothermic ones (with heat generation), the energy consumption for the processing of KVS into commercial products is reduced.

When implementing the method, titanium is not lost, and the method creates conditions where it can be concentrated in one of the produced alloys to a high content, for example, up to 70%.

Almost waste-free technology is being implemented.

The technological process is carried out with or without almost no gas evolution from the melt, which simplifies the design of the melting unit and eliminates the need to have equipment for the removal and purification of gases.

Information sources

1. Deryabin Yu.A., Smirnov L.A., Deryabin A.A. Prospects for processing Chinean titanomagnetites. - Yekaterinburg: Middle Ural book. Publishing House, 1999, 368 p.

2. Filippenkov A.A., Deryabin Yu.A., Smirnov L.A. Effective alloying technologies have become vanadium. - Yekaterinburg: Ural Branch of the Russian Academy of Sciences, 2001. JSBN5 - 7691 - 1193 - 3.

3. Patent of the Russian Federation No. 21545461. Method for the production of cast iron and steel. / Korshunov E.A., Smirnov L.A., Burkin S.P., Tarasov A.G., Loginov Yu.N., Sarapulov F.N. MKI C 21 V 11/00, application. 05.27.99, publ. 04/20/2001, Bulletin No. 11.

4. Patent of the Russian Federation No. 2245371. A method of processing red mud of alumina production. / Korshunov E.A., Burkin S.P., Loginov Yu.N., Loginova I.V., Andryukova E.A., Tretyakov B.C. IPC C21 3/04, 13/00, C22B 34/12, 59/00.

5. Patent of the Russian Federation No. 2207476. The melting unit. / Korshunov E.A., Sarapulov F.N., Burkin S.P., Tarasov A.G., Aragilyan O.A., Tretyakov B.C. MKI C21B 11/00, declared 05/14/2001.

Claims (10)

1. A method for the production of complex master alloys from converter vanadium slag (KSH), including the melting of a portion of KVS in a parabolic well formed by the electromagnetic field rotation of a liquid metal substrate, reduction of KVS oxides with a reducing agent and alloying of reduced metals with a substrate, separate discharge of metal and slag phases , characterized in that the reduction of vanadium, silicon, manganese, titanium, chromium, iron from KVS oxides is carried out on substrates formed in two melting units (P ), moreover, in the first PA on an iron-containing substrate, the temperature of which is maintained within the range of 1550-1600 ° C, silicon reduces iron and a part of vanadium, which are fused to the substrate, and after the majority of iron is recovered from a portion of the SHF, this part they are drained from the first PA, while the remaining iron-containing substrate is rotated from the first PA, the iron-depleted CFB is completely drained and transferred to the second PA, where it is first on the substrate from a titanium-containing complex ligature at a substrate temperature of up to 1700 ° C and The centrifuged supply of calcium oxide to it is reduced by titanium from vanadium, silicon, manganese, chromium, and iron from their oxides depleted in KHS, to obtain a complex ligature that does not contain titanium, and slag containing titanium and calcium oxides, the resulting complex ligature that does not contain titanium , in an amount of up to 70%, it is poured from PA, titanium is reduced from aluminum to aluminum, using reduced alloy titanium as the substrate remaining in the PA not containing titanium, a complex alloy, the temperature of which is increased to 1800-1900 ° C. vlyayut with the remaining part ligation to yield unfused complex titanium-ligature comprising metals from the iron-depleted portions of the traction sheave and the end slag is drained from the second PA. 2. The method according to claim 1, characterized in that the iron oxide is reduced with silicon, preventing a decrease in its content in the slag of less than 5-6%. 3. The method according to claim 2, characterized in that silicon is introduced into a mixture with KVS, respectively, with a given content of iron oxide in KVS depleted in iron. 4. The method according to claim 3, characterized in that silicon for the reduction of iron and vanadium is introduced in the composition of ferrosilicon. 5. The method according to claim 1, characterized in that after draining the depleted in KVS iron, it is cured, crushed and transferred in this form to the second PA. 6. The method according to claim 5, characterized in that the enrichment with titanium oxide is carried out by the addition of ilmenite. 7. The method according to claim 6, characterized in that ilmenite is added ferruginous to 80-90%. 8. The method according to claim 5, characterized in that the enrichment with titanium oxide is carried out by adding rutile. 9. The method according to claim 1, characterized in that the reduction of titanium from oxide is performed by aluminum from a ferroaluminium alloy, and the iron freed from aluminum is alloyed with the resulting titanium-containing alloy. 10. The method according to claim 1, characterized in that when transferring the depleted in iron KVS in the second PA, it is enriched with titanium oxide.