Ferrosilicon-vanadium-and / or niobium alloys, manufacture of ferrosilicon-vanadium-and / or niobium alloys and their use

Abstract

The present invention relates to a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy containing 15-80% by weight Si, 0.5-40% by weight V and / or Nb, up to 10% by weight Mo, up to 5% by weight Cr, up to 3% by weight Cu, up to 3% by weight Ni, up to 20% by weight Mg, 0.01-7% by weight Al, up to 13% by weight Ba, 0.01-7% by weight Ca, up to 13% by weight Mn, up to 8% by weight Zr, up to 12% by weight La and / or Ce and / or misch metal, up to 5% by weight Sr, up to 3% by weight Bi, up to 3% by weight Sb, up to 1.5% by weight Ti, balance Fe and incidental impurities. The present invention also relates to a method for producing the FeSiV and / or Nb alloy and its use in cast iron.

Description

Technical Field

[0001] The present invention relates to ferrosilicon-vanadium- and / or niobium alloys, a method for producing ferrosilicon-vanadium- and / or niobium alloys, and the use of such alloys. Specifically, it relates to ferrosilicon-vanadium- and / or niobium alloys that are particularly suitable as additives in the production of cast iron.

Background Art

[0002] Vanadium and niobium metals are known as additives that enhance the properties of cast iron, such as increasing strength, hardenability, and wear resistance, by micron- and nano-sized precipitated carbides and nitrides dispersed in the structure during solidification. This effect is called precipitation strengthening (see J.V. Dawson, International Exchange Paper, 1982, review). These small particles contribute to a metallurgical phenomenon called so-called dislocation pinning, which adds strength to the material when loaded up to yield. Fine carbide particles dispersed in the solid metal form a coherence with the metal matrix structure and introduce lattice strain into the material. Lattice strain and dislocation pinning are both phenomena that contribute to obtaining the desired strengthening effect. Vanadium and niobium are also pearlite accelerators in cast iron.

[0003] Vanadium is customarily added to molten iron in the form of ferrovanadium alloys. The most common one is FeV80 (80% vanadium), but other grades of alloys such as FeV60 (60% vanadium) or FeV50 are also used. Ferrovanadium alloys typically contain small amounts of silicon, aluminum, carbon, sulfur, phosphorus, arsenic, copper, manganese, titanium, chromium, and other impurities in addition to iron and vanadium.

[0004] Niobium is conventionally added to molten iron in the form of ferroniob alloys of various grades with a niobium content ranging from 60% to 70%. Ferroniob is produced from niobium pentoxide (Nb2O5) and iron oxide by the aluminothermite process and used either as is or after purification by electron beam melting. Depending on the grade, ferroniob contains less than 3% silicon and less than 2.5% aluminum, in addition to small amounts of carbon, sulfur, phosphorus, manganese, titanium, etc.

[0005] Conventional methods for producing ferrovanadium and ferroniob alloys involve silicon reduction and aluminum reduction. In both methods, reduction is carried out in a blast furnace, and vanadium oxide or niobium oxide is reduced by reaction with silicon or aluminum. These methods have the disadvantages of high energy consumption for carrying out the reaction and the presence of a considerable amount of vanadium oxide or niobium oxide in the slag at the end of the process, resulting in a relatively low yield of vanadium or niobium. Ferrovanadium and ferroniob alloys (FeV80 and FeNb66 have solidus temperatures of 1677°C and 1503°C, respectively) have relatively high melting points. As a result, the alloys do not melt on their own and need to be dissolved. The dissolution time when added to molten iron is long, so the addition of these alloys is limited to addition in a heated blast furnace, which can lead to valuable vanadium or niobium units entering the slag instead of the iron, especially when smaller particles are used, resulting in reduced recovery and instability. Furthermore, molten iron needs to be overheated to ensure the alloy is dissolved, or it needs to be held in the blast furnace for a longer period before tapping, which reduces the efficiency of cast iron production. In addition, the high density of FeV80 and especially FeNb65 is a drawback. FeNb65 falls to the bottom of the blast furnace, and insufficient stirring of the molten material can lead to a niobium imbalance.

[0006] Therefore, improved vanadium and / or niobium additives for use in the production of cast iron are desired. The object of the present invention is to mitigate, modify, or eliminate one or more of the drawbacks of the prior art identified above. [Overview of the project]

[0007] According to the first aspect, a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy containing 15-80 wt% Si, 0.5-40 wt% V and / or Nb, 10 wt% or less Mo, 5 wt% or less Cr, 3 wt% or less Cu, 3 wt% or less Ni, 20 wt% or less Mg, 0.01-7 wt% Al, 13 wt% or less Ba, 0.01-7 wt% Ca, 13 wt% or less Mn, 8 wt% or less Zr, 12 wt% or less La and / or Ce and / or mischmetal, 5 wt% or less Sr, 3 wt% or less Bi, 3 wt% or less Sb, 1.5 wt% or less Ti, the remainder Fe and associated impurities.

[0008] According to the first embodiment of the first aspect, the FeSiV and / or Nb alloy contains 15 to 29 wt% Si, 0.5 to 40 wt% V and / or Nb, 10 wt% or less Mo, 5 wt% or less Cr, 3 wt% or less Cu, 3 wt% or less Ni, 20 wt% or less Mg, 0.01 to 7 wt% Al, 13 wt% or less Ba, 0.01 to 7 wt% Ca, 13 wt% or less Mn, 8 wt% or less Zr, 12 wt% or less La and / or Ce and / or mischmetal, 5 wt% or less Sr, 3 wt% or less Bi, 3 wt% or less Sb, 1.5 wt% or less Ti, the remainder Fe, and associated impurities.

[0009] According to the second embodiment of the first aspect, the FeSiV and / or Nb alloy contains 30-50 wt% Si, 16-40 wt% V and / or Nb, 10 wt% or less Mo, 5 wt% or less Cr, 3 wt% or less Cu, 3 wt% or less Ni, 20 wt% or less Mg, 0.01-7 wt% Al, 13 wt% or less Ba, 0.01-7 wt% Ca, 13 wt% or less Mn, 8 wt% or less Zr, 12 wt% or less La and / or Ce and / or mischmetal, 5 wt% or less Sr, 3 wt% or less Bi, 3 wt% or less Sb, 1.5 wt% or less Ti, the remainder Fe, and associated impurities.

[0010] According to the third embodiment of the first aspect, the FeSiV and / or Nb alloy contains 51 to 80 wt% Si, 0.5 to 40 wt% V and / or Nb, 10 wt% or less Mo, 5 wt% or less Cr, 3 wt% or less Cu, 3 wt% or less Ni, 20 wt% or less Mg, 0.01 to 7 wt% Al, 13 wt% or less Ba, 0.01 to 7 wt% Ca, 13 wt% or less Mn, 8 wt% or less Zr, 12 wt% or less La and / or Ce and / or mischmetal, 5 wt% or less Sr, 3 wt% or less Bi, 3 wt% or less Sb, 1.5 wt% or less Ti, the remainder Fe, and associated impurities.

[0011] According to the first and third embodiments of the first aspect, the FeSiV and / or Nb alloy contains 5 to 35% by weight of V and / or Nb.

[0012] The following embodiments are not inconsistent with any of the embodiments described in the first aspect.

[0013] According to some embodiments, the FeSiV and / or Nb alloy contains 15% by weight or less of Mg.

[0014] According to some embodiments, the FeSiV and / or Nb alloy contains 5% by weight or less of Mo.

[0015] According to some embodiments, the melting temperature range of FeSiV and / or Nb alloys is 1060 to 1640°C.

[0016] According to some embodiments, the FeSiV and / or Nb alloy has the shape of whole grains or lumps measuring 0.06 to 50 mm.

[0017] According to some embodiments, particles or chunks of FeSiV and / or Nb alloy are coated or mixed with oxides of other metals such as bismuth oxide and / or bismuth sulfide and / or antimony sulfide and / or antimony oxide and / or iron oxide and / or sulfides of other metals such as iron sulfide.

[0018] According to some embodiments, FeSiV and / or Nb alloys are additives used in the production of cast iron.

[0019] According to the second aspect, a method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy as described in the first aspect and any embodiment thereof, wherein the method for producing the alloy is: A process of supplying molten ferrosilicon alloy, A process of adding vanadium oxide-containing raw materials and / or niobium oxide-containing raw materials to a molten ferrosilicon alloy. A process of mixing molten ferrosilicon alloy with vanadium oxide derived from vanadium oxide-containing raw materials and / or niobium oxide derived from niobium oxide-containing raw materials, and reacting them to form molten FeSiV and / or Nb alloy and slag. A step of separating slag from the molten material, and The process involves solidifying the molten FeSiV and / or Nb alloy or placing it into a mold, It has.

[0020] According to some embodiments of the manufacturing method, the molten ferrosilicon alloy is supplied directly from a reducing furnace, and the ferrosilicon is as it is produced from the raw materials by conventional methods.

[0021] According to some embodiments of the manufacturing method, the molten ferrosilicon alloy is supplied by remelting a charge of one or more types of ferrosilicon alloys.

[0022] According to some embodiments of the manufacturing method, vanadium oxide-containing raw materials and / or niobium oxide-containing raw materials are added in an amount (by weight) that essentially supplies the target amount (by weight) of the elements vanadium and / or niobium to the FeSiV and / or Nb alloy.

[0023] According to some embodiments of the manufacturing method, the vanadium oxide-containing raw material is one or more vanadium oxide phases selected from vanadium(II) oxide, vanadium(III) oxide, vanadium(IV) oxide, vanadium(V) oxide, and / or other non-principal-axis oxides of vanadium.

[0024] According to some embodiments of the manufacturing method, the niobium oxide-containing raw material is one or more niobium oxide phases selected from niobium(II) oxide, niobium(III) oxide, niobium(IV) oxide, niobium(V) oxide, and / or other non-principal-axis oxides of niobium.

[0025] According to some embodiments of the manufacturing method, the vanadium oxide phase is vanadium(V) oxide, V2O5, and / or vanadium(III) oxide, V2O3. , ,

[0030] , , ,

[0031] , , ,

[0029] , ,

[0028]

[0026] According to some embodiments of the manufacturing method, the niobium oxide phase is niobium(V) oxide, Nb2O5, and / or niobium(III) oxide, Nb2O3. 。

[0027] According to some embodiments of the manufacturing method, the vanadium oxide-containing raw material further includes industrial waste materials containing vanadium oxide or ores.

[0028] According to some embodiments of the manufacturing method, the niobium oxide-containing raw material further includes industrial waste materials containing niobium oxide or ores.

[0029] According to some embodiments of the manufacturing method, a compound for modifying the slag is added to the molten ferrosilicon alloy in an amount of 0.5 to 30% by weight based on the total amount of the ferrosilicon alloy, vanadium oxide, and / or niobium oxide.

[0030] According to some embodiments of the manufacturing method, the compound for modifying the slag is at least one of at least CaO and MgO.

[0031] According to several embodiments of the manufacturing method, molten ferrosilicon alloy is, 40-90% by weight of Si, C of 0.5% by weight or less, 0.01-7% by weight of Al, Ca at 6% by weight or less, 1.5% by weight or less of Ti, Mn, 15% by weight or less Cr less than 10% by weight, 10% by weight or less of Zr, Ba at 15% by weight or less, P is less than 0.3% by weight. S, 0.5% by weight or less The remainder consists of Fe and associated impurities.

[0032] According to some embodiments of the manufacturing method, the manufacturing method further comprises the step of adding aluminum to the ferrosilicon molten material in an amount of 10% by weight or less relative to the total amount of ferrosilicon alloy and vanadium oxide and / or niobium oxide, either simultaneously with or after the addition of vanadium oxide-containing raw materials and / or niobium oxide-containing raw materials.

[0033] According to some embodiments of the manufacturing method, the molten ferrosilicon alloy and the vanadium oxide-containing raw material and / or niobium oxide-containing raw material, and the added aluminum and / or slag-modifying compound are mixed by mechanical stirring or gas stirring.

[0034] According to some embodiments of the manufacturing method, the slag is separated before or during the process of pouring the molten ferrosilicon-vanadium-and / or niobium alloy into the mold.

[0035] According to some embodiments of the manufacturing method, the ferrosilicon-vanadium-and / or niobium alloy is placed in a mold and solidified, forming blocks, or is crushed and optionally graded into size fractions, or aggregated.

[0036] A third aspect is the use of a ferrosilicon-vanadium-and / or niobium alloy as an additive in the production of vanadium and / or niobium-containing cast iron, as described in the first aspect and any embodiment of the first aspect.

[0037] The present invention will be clarified by the following detailed description. The disclosed detailed description and specific examples are merely illustrative of preferred embodiments of the present invention. Those skilled in the art will understand, as indicated in the detailed description, that changes and modifications may be made within the scope of the present invention.

[0038] Therefore, it should be understood that the inventions disclosed herein are not limited to specific components of the described apparatus or steps of the described method, because the apparatus or steps may be modified. Furthermore, it should be understood that the techniques used herein are intended to describe specific embodiments only and are not intended to limit them. The articles “a,” “an,” “the,” and “said” used herein and in the appended claims are intended to mean one or more elements unless the context clearly indicates otherwise. For example, “a unit” or “the unit” may include several apparatuses, etc. Furthermore, the words “comprising,” “including,” “containing,” and similar expressions do not exclude other elements or steps.

[0039] It should be understood that the term "associated impurities" refers to small amounts of impurity elements present in ferrosilicon-vanadium-and / or niobium alloys or ferrosilicon alloys.

[0040] In this context, the term “ferrosilicon alloy” (also referred to as “ferrosilicon,” “FeSi alloy,” or simply “FeSi”) should be understood as iron containing a silicon alloy, typically produced in a submerged arc furnace (SAF) by reducing silica or sand with coke (or any other conventional carbon material used as a charge material) in the presence of iron or an iron source. Commonly available commercially are ferrosilicon containing 15%, 45%, 65%, 75%, and 90% (by weight) silicon. As-manufactured ferrosilicon alloys typically contain about 2% by weight of other elements, mainly aluminum and calcium, but also commonly contain small amounts of carbon, titanium, copper, manganese, phosphorus, and sulfur. In this context, ferrosilicon alloys may also contain, for example, manganese and / or chromium and / or zirconium and / or barium as alloying elements, or, for example, ferrosilicon and mixtures of ferrosilicon-manganese and / or ferrosilicon-chromium and / or ferrosilicon-zirconium and / or ferrosilicon-barium. In this context, for the sake of simplicity, all such possible alloys will be referred to as ferrosilicon alloys ("ferrosilicon," "FeSi alloy," or simply "FeSi") as described above.

[0041] In this context, the term “ferrosilicon-vanadium-and / or niobium alloy” (or also referred to as “FeSiV and / or Nb alloy” or simply “FeSiV and / or Nb”) should be understood as a ferrosilicon alloy containing vanadium or niobium, or containing both vanadium and niobium. In addition to vanadium and / or niobium, other elements specified in the first aspect may also be present in the alloy.

[0042] In this context, the term "below" used to indicate the amount of an element should be understood to mean that the element exists within a range from 0% by weight to the indicated weight percentage value. [Brief explanation of the drawing]

[0043] [Figure 1]This figure shows a comparison of the melting times of different FeSiV alloys described in one embodiment of the present invention in molten cast iron at 1400°C. [Figure 2] This figure shows a comparison of the melting times of different FeSiV alloys described in one embodiment of the present invention and a standard FeV80 alloy in molten cast iron at 1500°C. [Figure 3] This figure shows a comparison of the melting times of different FeSiNb alloys described in one embodiment of the present invention and a standard FeNb65 alloy in molten cast iron at 1500°C. [Figure 4] This figure shows a comparison of the time it takes for FeSiNbV alloy and FeSiNbVMo alloy described in one embodiment of the present invention, as well as standard FeNb65 alloy and standard FeV80 alloy, to melt in molten cast iron at 1500°C. [Modes for carrying out the invention]

[0044] (Detailed explanation) The ferrosilicon-vanadium-and / or niobium alloy of the first side is particularly suitable for use as an additive in cast iron production, and is suitable for cast iron production containing vanadium and / or niobium. The first aspect of the present invention relates to FeSiV and / or Nb alloys containing 15-80 wt% silicon (Si), 0.5-40 wt% vanadium (V) and / or niobium (Nb), 10 wt% or less molybdenum (Mo), 5 wt% or less chromium (Cr), 3 wt% or less Cu, 3 wt% or less Ni, 20 wt% or less magnesium (Mg), 0.01-7 wt% aluminum (Al), 13 wt% or less barium (Ba), 0.01-7 wt% calcium (Ca), 13 wt% or less manganese (Mn), 8 wt% or less zirconium (Zr), 12 wt% or less lanthanum (La) and / or cerium (Ce) and / or mischmetal, 5 wt% or less strontium (Sr), 3 wt% or less bismuth (Bi), 3 wt% or less antimony (Sb), 1.5 wt% or less titanium (Ti), the remainder being iron (Fe), and associated impurities.

[0045] This FeSiV and / or Nb alloy is particularly suitable as an additive in cast iron production.

[0046] Furthermore, the FeSiV and / or Nb alloys of the present invention have a lower melting temperature and a different dissolution pathway in molten cast iron compared to conventional FeV80 and FeNb65 alloys. The lower melting temperature and different dissolution pathway result in a significantly higher dissolution rate in molten iron compared to FeV80 and FeNb65 alloys. The lower melting temperature and higher dissolution rate lead to reduced energy consumption when added to molten cast iron, resulting in better dispersion of vanadium and / or niobium in the molten material, and the relatively low density of the alloys derived from the present invention may also improve dispersion. Moreover, the higher dissolution rate means that the ferrosilicon-vanadium- and / or niobium additive alloy can be added later in the cast iron manufacturing process, which may lead to greater flexibility in the casting process.

[0047] Furthermore, the density of the FeSiV and / or Nb alloy according to the present invention is lower than that of the FeV80 alloy and the FeNb65 alloy. Even when added in the blast furnace or at the bottom of the ladle, the melting of the alloy does not lead to an imbalance of V and Nb at the bottom. For example, when added at the bottom of the ladle, the alloy pieces according to the present invention have a lower density than iron and begin to rise as they melt. On the other hand, for example, FeNb65 pieces remain at the bottom of the ladle, melt there, and lead to a higher concentration of niobium at the bottom.

[0048] Silicon is a common additive in cast iron production. Silicon is an alloying element present in cast iron in amounts ranging from 1 to 4.3% by weight. Silicon plays an important role in the production of cast iron (gray cast iron, which is compressible and ductile) and helps in graphite nucleation more than cementite. Silicon is also known to enhance strength, wear resistance, elasticity, and oxidation resistance. The silicon content in this FeSiV and / or Nb alloy is 15 to 80% by weight. In one embodiment, the silicon content is at least 15% by weight, at least 30% by weight, or at least 45% by weight, for example, at least 51% by weight or at least 55% by weight. In one embodiment, the silicon content is 75% by weight or less, for example, 65% by weight or less, or 50% by weight or less, or 29% by weight or less.

[0049] The FeSiV and / or Nb alloy of the present invention contains 0.5 to 40 wt% of V and Nb. If only V is present, it means that it may be present in the range of 0.5 to 40 wt%. If only Nb is present, it may be present in the range of 0.5 to 40 wt%. If both V and Nb are present, the total amount of V and Nb in the alloy is in the range of 0.5 to 40 wt%. If both V and Nb are present, the ratio of V to Nb may be any ratio within a given range. In one embodiment, the V and / or Nb content is 5 to 35 wt%. Vanadium and niobium form stable nitrides and carbides, resulting in a considerable increase in the strength of the cast iron. The cast iron may also be strengthened by pearlite enhancement, refined pearlite lamellar spacing, or controlled cell structure derived from microalloing elements (V, Nb). The age hardening effect during annealing heat treatment (typically 1000 to 1100°C) may also be obtained from the dissolution of the first carbide and the reprecipitation of nanocarbides during cooling. Impact toughness, especially in samples without notches, fatigue life characteristics under repeated loading of castings, and improved wear resistance due to carbide precipitates, particularly in gray cast iron, are other improvements related to the use of V and Nb. Austempered iron (ADI) is a heat-treated material with excellent strength, wear properties, and fatigue properties. In the production of ADI, alloying elements such as V and Nb are often applied to improve hardenability.

[0050] The ranges of V and Nb relative to Si in FeSiV alloys may depend on the amount of Si in the starting ferrosilicon alloy that is the raw material for the FeSiV and / or Nb alloys. For example, FeSi50 or FeSi65 alloys may have higher ranges of V and Nb relative to Si than, for example, FeSi75 alloy when it is the starting alloy.

[0051] In some embodiments, the FeSiV and / or Nb alloy contains 15-29 wt% Si, 0.5-40 wt% V and / or Nb, for example, 5-35 wt% V and / or Nb or 9-30 wt% V and / or Nb, and other elements specified above by the first aspect (10 wt% or less molybdenum (Mo), 5 wt% or less chromium (Cr), 3 wt% or less copper (Cu), 3 wt% or less nickel (Ni), 20 wt% or less magnesium (Mg), 0.01-7 wt% It contains aluminum (Al), barium (Ba) at 13% by weight or less, calcium (Ca) at 0.01 to 7% by weight, manganese (Mn) at 13% by weight or less, zirconium (Zr) at 8% by weight or less, lanthanum (La) at 12% by weight or less and / or cerium (Ce) and / or mischmetal, strontium (Sr) at 5% by weight or less, bismuth (Bi) at 3% by weight or less, antimony (Sb) at 3% by weight or less, titanium (Ti) at 1.5% by weight or less, the remainder being Fe and associated impurities.

[0052] In some embodiments, the FeSiV and / or Nb alloy contains 30-50 wt% Si, 16-40 wt% for example, 16-35 wt% V and / or Nb or 16-30 wt% V and / or Nb, and other elements specified above by the first aspect (10 wt% or less molybdenum (Mo), 5 wt% or less chromium (Cr), 3 wt% or less copper (Cu), 3 wt% or less nickel (Ni), 20 wt% or less magnesium (Mg), 0.01-7 wt% aluminum ( It contains Al, barium (Ba) 13% by weight or less, calcium (Ca) 0.01 to 7% by weight, manganese (Mn) 13% by weight or less, zirconium (Zr) 8% by weight or less, lanthanum (La) 12% by weight or less and / or cerium (Ce) and / or mischmetal, strontium (Sr) 5% by weight or less, bismuth (Bi) 3% by weight or less, antimony (Sb) 3% by weight or less, titanium (Ti) 1.5% by weight or less, the remainder being Fe and associated impurities.

[0053] In another embodiment, the FeSiV and / or Nb alloy contains 51-80 wt% Si, for example 55-75 wt% Si, or 58-72 wt% Si, or 60-72 wt% Si, 0.5-40 wt% V and / or Nb, for example 5-35 wt% V and / or Nb, or 9-30 wt% V and / or Nb, and other elements specified above by the first aspect (10 wt% or less molybdenum (Mo), 5 wt% or less chromium (Cr), 3 wt% or less copper (Cu), 3 wt% or less nickel (Ni), 20 wt% or less It contains magnesium (Mg), 0.01 to 7% by weight of aluminum (Al), 13% or less by weight of barium (Ba), 0.01 to 7% by weight of calcium (Ca), 13% or less by weight of manganese (Mn), 8% or less by weight of zirconium (Zr), 12% or less by weight of lanthanum (La) and / or cerium (Ce) and / or mischmetal, 5% or less by weight of strontium (Sr), 3% or less by weight of bismuth (Bi), 3% or less by weight of antimony (Sb), 1.5% or less by weight of titanium (Ti), the remainder being Fe and associated impurities.

[0054] It should be understood that the ranges of V and Nb for some Si can be realized with the compositions specified above.

[0055] FeSiV and / or Nb alloys contain 10% by weight or less of Mo. According to some embodiments, FeSiV and / or Nb alloys contain 5% by weight or less, or 3% by weight or less, or 1% by weight or less of Mo. Molybdenum is also an alloying element used in several grades of cast iron, such as austempered iron. Molybdenum provides hardenability and a stable structure for high-temperature applications. In gray cast iron, molybdenum has been reported to increase tensile strength (20% at 0.5% by weight in cast iron) and hardness (10% at 0.5% by weight in cast iron). Molybdenum is used in the smelting of pearlite.

[0056] FeSiV and / or Nb alloys contain 5% by weight or less of Cr. According to some embodiments, FeSiV and / or Nb alloys contain 2% by weight or less of Cr. Cr is an alloying element and has been reported to increase tensile strength and hardness. It is used in combination with vanadium and / or niobium in some cast iron grades.

[0057] FeSiV and / or Nb alloys contain 3% by weight or less of Cu. According to some embodiments, FeSiV and / or Nb alloys contain 1% by weight or less of Cu, or 0.5% by weight or less. Copper can be used to prevent the formation of strong eutectic iron carbide, which is promoted by vanadium and / or niobium.

[0058] FeSiV and / or Nb alloys contain 3% by weight or less of Ni. According to some embodiments, FeSiV and / or Nb alloys contain 1% by weight or less of Ni, or 0.5% by weight or less. Nickel can be used to prevent the formation of strong eutectic iron carbide, which is promoted by vanadium and / or niobium.

[0059] The following disclosures relating to the amounts of further elements Mg, Al, Ba, Ca, Mn, Zr, La, Ce, Sr, Bi, Sb, Ti, the remainder Fe, and associated impurities apply to each of the above embodiments unless otherwise specified. These elements are commonly used in treatment alloys for the production of cast iron.

[0060] FeSiV and / or Nb alloys contain 20% by weight or less of Mg. According to some embodiments, FeSiV and / or Nb alloys contain 15% by weight or less of Mg or 10% by weight or less of Mg. In some embodiments, alloys with low Si concentrations, such as Si in the range of 15-35% by weight, may not contain Mg. Magnesium is mainly used in nodding processes to desulfurize and reduce the molten material, resulting in a change in the shape of graphite from flakes to nodules. Magnesium is also used in low concentrations as an inoculant. The solubility of magnesium in iron is finite, and there is a lower limit to the amount of silicon required in ferrosilicon alloys for magnesium alloying.

[0061] FeSiV and / or Nb alloys contain 0.01 to 7% by weight of Al. According to some embodiments, FeSiV and / or Nb alloys contain 0.01 to 5% by weight or 0.05 to 5% by weight of Al.

[0062] The FeSiV and / or Nb alloy contains 13% by weight or less of Ba. According to some embodiments, the FeSiV and / or Nb alloy contains 11% by weight or less of 8% by weight or less of Ba, for example, 6% by weight or less. In some embodiments, the FeSiV and / or Nb alloy may contain 1 to 5% by weight of Ba and 11 to 40% by weight of V and / or Nb.

[0063] FeSiV and / or Nb alloys contain 0.01 to 7% by weight of Ca. According to some embodiments, FeSiV and / or Nb alloys contain 0.01 to 5% by weight or 0.05 to 5% by weight of Ca.

[0064] The FeSiV and / or Nb alloy contains 13% by weight or less of Mn. According to some embodiments, the FeSiV and / or Nb alloy contains 8% by weight or less or 5% by weight or less of Mn. In some embodiments, the FeSiV and / or Nb alloy may contain 13% by weight or less, 8% by weight or less or 5% by weight or less of Mn and 10 to 40% by weight of V and / or Nb.

[0065] FeSiV and / or Nb alloys contain 8% by weight or less of Zr. According to some embodiments, FeSiV and / or Nb alloys contain 5% by weight or less of Zr.

[0066] FeSiV and / or Nb alloys contain 12% by weight or less of La and / or Ce and / or mischmetal. According to some embodiments, FeSiV and / or Nb alloys contain 7% by weight or less of La and / or Ce and / or mischmetal. According to some embodiments, FeSiV and / or Nb alloys contain 4% by weight or less of La and / or Ce and / or mischmetal. Mischmetal is an alloy of rare earth elements, typically containing about 50% Ce and 25% La, with small amounts of Nd and Pr. Recently, heavier rare earth metals are often removed from mischmetal, and the alloy composition of mischmetal is about 65% Ce and about 35% La and trace amounts of heavier rare earth metals such as Nd and Pr.

[0067] FeSiV and / or Nb alloys contain 5% by weight or less of Sr. According to some embodiments, FeSiV and / or Nb alloys contain 3% by weight or less of Sr.

[0068] FeSiV and / or Nb alloys contain 3% by weight or less of Bi. According to some embodiments, FeSiV and / or Nb alloys contain 1.8% by weight or less of Bi.

[0069] FeSiV and / or Nb alloys contain 3% by weight or less of Sb. According to some embodiments, FeSiV and / or Nb alloys contain 1.5% by weight or less of Sb.

[0070] FeSiV and / or Nb alloys contain 1.5% by weight or less of Ti. According to some embodiments, FeSiV and / or Nb alloys contain 0.5% by weight or less of Ti. Titanium is typically present in small amounts in the starting ferrosilicon alloy. Titanium may also originate from vanadium oxide and / or niobium oxide raw materials added during the production of FeSiV and / or Nb alloys. Titanium can form hard carbides or nitrides, leading to reduced brittleness and fatigue stress, and is therefore detrimental in some cast iron grades. Titanium also reduces the tolerance for other fracture elements. Therefore, the Ti content in FeSiV and / or Nb alloys is preferably low, for example, 0.1% by weight or less or 0.05% by weight or less.

[0071] FeSiV and / or Nb alloys contain small amounts of C, P, and S. These elements are typically present in small amounts in as-manufactured ferrosilicon or are added during the production of FeSiV and / or Nb alloys via vanadium oxide and / or niobium oxide raw materials and / or slag-modifying compounds. Estimated amounts of these elements are generally not important for cast iron production. Of the above elements, P is the most likely to cause problems because it leads to the formation of low-melting-point steadites found in the last solidifying region. Steadites undergo considerable shrinkage during solidification, leading to shrinkage porosity and reduced strength.

[0072] FeSiV and / or Nb alloys are conveniently shaped as lumps according to any of the embodiments described above. In this context, the term "lump" refers to particles or alloy pieces of FeSiV and / or Nb alloy, for example, crushed FeSiV and / or Nb metal. FeSiV and / or Nb alloy lumps may be manufactured in various size grades. According to some embodiments, FeSiV and / or Nb alloys are shaped as whole particles or lumps ranging from 0.06 to 50 mm. Typical sizing used in cast iron manufacturing processes ranges from about 0.2 mm to about 50 mm. The term "sizing" refers to the size of the sieve holes through which the lumps can just barely pass. Therefore, according to some embodiments, FeSiV and / or Nb alloys are shaped as whole particles or lumps ranging from 0.2 to 50 mm. The average size may vary within a certain range, and it should be understood that smaller or larger FeSiV and / or Nb lumps may be available depending on the application. According to some embodiments, the FeSiV and / or Nb alloy is in the form of an insert, such as an ingot or an agglomeration of powdered material.

[0073] According to some embodiments, FeSiV and / or Nb particles can be coated or mixed with bismuth oxide and / or bismuth sulfide and / or antimony sulfide and / or antimony oxide and / or iron oxide and / or sulfides of other metals.

[0074] The melting temperature of FeSiV and / or Nb alloys is in the range of about 1060 to about 1640°C or about 1610°C, according to any of the embodiments described above. The relatively low melting temperature of the FeSiV and / or Nb alloys of the present invention and the different dissolution pathways into the molten iron have the effect of allowing the FeSiV and / or Nb alloy added to the molten iron to melt relatively quickly. Tests conducted by the inventors have shown that a lump of FeSiV (30 wt% V) of the present invention, approximately 18 mm in size, was completely assimilated into the molten iron after 50 seconds at 1400°C, while a lump of FeV80 of the same size was still not assimilated at all after 3 minutes. The assimilation time of a larger 20 mm lump of FeNb65 at 1500°C was twice as long as that of FeSiNb20.

[0075] Figure 1 shows the melting time of different FeSiV alloys according to the present invention in molten iron at approximately 1400°C. The figure shows the melting time for differences in the size of the FeSiV alloy grains. At this temperature, lumps of FeV80 ranging in size from 7 to 18 mm were monitored for approximately 3 minutes but did not melt at all and are therefore not shown in the figure.

[0076] Figure 2 shows the dissolution time of different FeSiV alloys according to the present invention in molten iron at approximately 1500°C, compared to a standard commercially available FeV80 alloy. The figure shows the dissolution time for differences in the grain size of FeSiV alloy and FeV80 lumps. The dissolution time of FeV80 alloy becomes considerably longer compared to FeSiV alloy as the size of the lumps added to the molten iron increases. Table 3 shows that FeSiV alloy has a considerably higher V yield compared to FeV80, even though the grain size when added to the molten iron is the same for both alloys.

[0077] Figure 3 shows the melting time of different FeSiNb alloys according to the present invention in a molten iron at approximately 1500°C, compared to a standard commercially available FeNb65 alloy. The figure shows the melting time for differences in the grain size of FeSiNb alloy and FeNb65 lumps. The melting time of FeV80 alloy becomes considerably longer compared to FeSiV alloy as the size of the lumps added to the molten iron increases. Table 6 shows that FeSiNb alloy has a considerably higher Nb yield compared to FeNb65, even though the grain size when added to the molten iron is the same for both alloys.

[0078] Figure 4 shows the melting time of the FeSiNbV alloy and FeSiNbVMo alloy according to the present invention in molten iron at approximately 1500°C, compared to standard commercially available FeV80 alloy and FeNb65 alloy. The figure shows the melting time of FeSiNbV alloy, FeSiNbVMo alloy, FeNb65, and FeV80 with respect to differences in the size of the lumps. The melting time of FeV80 and FeNb65 alloys becomes considerably longer compared to FeSiNbV and FeSiNbVMo alloys as the size of the lumps added to the molten iron increases.

[0079] A method for producing FeSiV and / or Nb alloy according to any of the above embodiments includes the steps of: supplying a molten ferrosilicon alloy; adding a vanadium oxide-containing raw material and / or a niobium oxide-containing raw material to the molten ferrosilicon alloy; mixing and reacting the molten ferrosilicon alloy with vanadium oxide derived from the vanadium oxide-containing raw material and / or niobium oxide derived from the niobium oxide-containing raw material to form a molten FeSiV and / or Nb alloy and slag; separating the slag from the molten FeSiV and / or Nb alloy; any step of adjusting the elemental composition described in the first aspect; and solidifying the molten FeSiV and / or Nb alloy or placing it in a mold.

[0080] The following detailed description of the manufacturing method for FeSiV and / or Nb alloys applies to any of the above embodiments of the FeSiV and / or Nb alloys of the present invention.

[0081] The reaction between molten ferrosilicon alloy and vanadium oxide and / or niobium oxide is rapid, enabling high productivity. The method for producing FeSiV and / or Nb alloys is carried out in any similar suitable container, such as a ladle or crucible holding molten ferrosilicon or a molten pot containing any type of blast furnace. Therefore, heating by supplying external energy, such as using a blast furnace, is not necessary. The temperature of the molten ferrosilicon before adding the vanadium oxide-containing raw material and / or niobium oxide-containing raw material should be approximately 1400 to 1700°C. The method for producing FeSiV and / or Nb alloys of the present invention yields a high V and / or Nb yield from vanadium oxide (e.g., vanadium pentoxide) and / or niobium oxide (e.g., niobium oxide) to FeSiV and / or Nb alloys compared to conventional methods for producing ferrovanadium alloys, FeV and ferroniob alloys, and FeNb. Compared to conventional methods for producing FeV and FeNb, this method is simpler and more cost-effective.

[0082] Molten ferrosilicon alloys can be supplied from a reducing furnace, typically directly from a buried arc furnace (SAF) in which the ferrosilicon alloy remains as it was produced from the raw materials by conventional methods, or from an alloying site where the elements described in Aspect 1 other than vanadium and / or niobium are alloyed into ferrosilicon supplied directly from the reducing furnace. Alternatively, molten ferrosilicon alloys can be supplied from a charge of one or more ferrosilicon alloys that are as refined as possible and already alloyed with the elements described in Aspect 1 other than vanadium and / or niobium, or by remelting a combination of as-produced ferrosilicon alloy and solidified ferrosilicon brought to a molten state by any suitable heating means.

[0083] According to some embodiments of the manufacturing method, the starting ferrosilicon alloy may be a mixture of several ferrosilicon alloys of different compositions. For example, it may be a mixture of ferrosilicon with ferrosilicon manganese, ferrosilicon chromium, ferrosilicon zirconium, or ferrosilicon barium.

[0084] According to the manufacturing method, a vanadium oxide-containing raw material, such as V2O5, and / or a niobium oxide-containing raw material, such as Nb2O5, are added to the molten ferrosilicon alloy. The amount of vanadium oxide-containing raw material and / or niobium oxide-containing raw material added may be such that it essentially supplies the target amount (by weight) of vanadium and / or niobium of the element to the FeSiV and / or Nb alloy. The method of adding the vanadium oxide-containing raw material and / or niobium oxide-containing raw material is not critical and may be carried out by any convenient method.

[0085] The vanadium oxide-containing raw material may be one or more vanadium oxide phases such as vanadium(II) oxide, vanadium(III) oxide, vanadium(IV) oxide, vanadium(V) oxide, and / or other non-main axis oxides of vanadium. The vanadium oxide is preferably vanadium(V) oxide (V2O5) and / or vanadium(III) oxide (V2O3), which are the vanadium oxides most commonly used in industrial applications. The vanadium oxide-containing raw material may also include industrial waste materials or ores containing vanadium oxide.

[0086] The niobium oxide-containing raw material may be one or more niobium oxide phases such as niobium(II) oxide, niobium(III) oxide, niobium(IV) oxide, niobium(V) oxide, and / or other non-core oxides of niobium. The niobium oxide phase is preferably niobium(V) oxide, (Nb2O5) and / or niobium(III) oxide, Nb2O3, which are the niobium oxides most commonly used in industrial applications. 。 Niobium oxide-containing raw materials may also contain industrial waste materials or ores containing niobium oxide.

[0087] The reduction reaction of vanadium oxide and / or niobium oxide leads to the formation of an oxide compound, commonly referred to as slag, which mainly contains aluminum oxide, silicon oxide, and calcium oxide. To modify the slag formed during the reaction, a slag-modifying compound may be added to the ferrosilicon molten material. The slag-modifying compound may be CaO and / or MgO, and may be added in an amount of about 0.5 to 30% by weight of the final alloy relative to the total amount of the ferrosilicon alloy. The required amount depends on the amount of vanadium oxide and / or niobium oxide added. The slag-modifying compound may be added before or during the addition of the vanadium oxide-containing raw materials and / or niobium oxide-containing raw materials. The composition of the slag is modified to be low viscosity and low melting point so that the slag and metal come into good contact during the reduction reaction. In addition, it may be modified so that the metal and slag separate well before being placed in the mold. Both the slag produced during the reaction and the added slag float on top of the molten material, so that any formed waste and any slag compounds formed during the reaction accumulate in the layer of slag floating on top of the molten material.

[0088] A typical composition of a starting ferrosilicon alloy for the production of FeSiV and / or Nb alloys is 40-90 wt% Si, 0.5 wt% or less C, 0.01-7 wt% Al, 6 wt% or less Ca, 1.5 wt% or less Ti, 15 wt% or less Mn, 10 wt% or less Cr, 10 wt% or less Zr, 15 wt% or less Ba, 0.3 wt% or less P, 0.5 wt% or less S, the remainder Fe, and associated impurities.

[0089] According to some embodiments of the manufacturing method, the Si content in the starting ferrosilicon alloy is 70-80% by weight. According to some embodiments of the manufacturing method, the Si content in the starting ferrosilicon alloy is 60-70% by weight. According to some embodiments of the manufacturing method, the Si content in the starting ferrosilicon alloy is 40-55% by weight.

[0090] As-manufactured ferrosilicon alloys contain a small amount of Al from the raw materials, generally less than 1.5% by weight. The starting ferrosilicon alloy of the present invention may contain less than 2% by weight of Al, for example, 0.01 to 2% by weight. When vanadium oxide-containing raw materials and / or niobium oxide-containing raw materials are added to the molten ferrosilicon alloy, the Al present in the molten ferrosilicon reacts with the oxygen of vanadium oxide and / or niobium oxide, reducing it to vanadium and / or niobium, resulting in the acquisition of pure V and / or Nb, and generating heat. Si in the molten ferrosilicon alloy also reacts with the oxygen of vanadium oxide and / or niobium oxide, resulting in the reduction of vanadium oxide to element V and niobium oxide to element Nb. Since Si is less reactive than Al in this mixture, substantially all of the Al present in the ferrosilicon alloy reacts with the oxygen of vanadium oxide and / or niobium oxide, resulting in a very small amount of Al in the produced FeSiV and / or Nb alloy. Calcium is also a common element in ferrosilicon alloys, usually present in amounts of about 1.5% by weight or less. Ca present in molten ferrosilicon alloys also reacts with the oxygen of vanadium oxide and / or niobium oxide, resulting in the release of pure V and / or Nb, which is exothermic.

[0091] Additional aluminum may be added to the molten ferrosilicon alloy to increase the amount of Al in the molten material that can be used to reduce vanadium oxide and / or niobium oxide. This is particularly valuable when producing FeSiV and / or Nb alloys that have a large amount of vanadium and / or niobium, while keeping the amount of silicon in the FeSiV and / or Nb alloy within the above ranges, from FeSiV and / or Nb10 (FeSiV and / or Nb10) to FeSiV and / or Nb20, FeSiV and / or Nb30, and even FeSiV and / or Nb40. When additional aluminum is added to the molten ferrosilicon, the addition may be made before, during, or after the addition of the vanadium oxide-containing raw material and / or niobium oxide-containing raw material, preferably before or during. Metallic aluminum may be added in an amount of about 10% by weight or less, about 5% by weight or less, or about 1% by weight or less, relative to the total amount of ferrothicone and vanadium oxide and / or niobium oxide.

[0092] The molten ferrosilicon alloy is preferably stirred to ensure that the V and Nb oxides and the metal are in contact during the addition of vanadium oxide-containing raw materials and / or niobium oxide-containing raw materials, and during the addition of any additional aluminum and / or slag-modifying compounds, and during the reduction reaction. The molten material is conventionally stirred by mechanical stirring and / or gas stirring as commonly known in this art.

[0093] The slag may be separated before or during the casting of the molten ferrosilicon-vanadium- and / or niobium alloy into the mold. The FeSiV and / or Nb alloy is cast into the mold and solidified according to methods commonly known in this art. The cast and solidified metal is crushed and graded into size fractions suitable for various application areas. The cast and solidified FeSiV and / or Nb alloy may also be in the form of aggregates or blocks.

[0094] The FeSiV and / or Nb alloy of the present invention may be used as an additive in the production of cast iron containing vanadium and / or niobium.

[0095] According to some embodiments, FeSiV and / or Nb alloys may be alloyed with additional elements Mo, Cu, Cr, Ni, Mg, Al, Ba, Ca, Mn, Zr, La and / or Ce and / or mischmetal, Sr, Bi, Sb, following standard procedures for the production of casting additives.

[0096] According to some embodiments, casting additives comprising 10% by weight or less of Mo, 5% by weight or less of Cr, 3% by weight or less of Cu, 3% by weight or less of Ni, 20% by weight or less of Mg, 0.01 to 7% by weight of Al, 13% by weight or less of Ba, 0.01 to 7% by weight of Ca, 13% by weight or less of Mn, 8% by weight or less of Zr, 12% by weight or less of La and / or Ce and / or mischmetal, 5% by weight or less of Sr, 3% by weight or less of Bi, 3% by weight or less of Sb, 1.5% by weight or less of Ti, the remainder being Fe, and associated impurities may also be used as the starting ferrosilicon alloy.

[0097] Granulated alloys may be packed into cored wires, for example, or mixed with other alloys and packed together. Ferrosilicon-based vanadium and / or niobium alloys alloyed with additional elements may be used as preconditioners, as cover materials in casing agglomeration processes, as agglomerating agents, as crushed inoculants with or without coating, or as inserts for agglomeration of ingots or powdered materials. Any type of ferrosilicon-based vanadium and / or niobium alloy may be used in cored wires, further alloyed with other elements, coated with other elements, or uncoated.

[0098] A method for producing cast iron, comprising the step of adding an FeSiV and / or Nb alloy containing 15-80 wt% silicon (Si), 0.5-40 wt% vanadium (V) and / or niobium (Nb), 10 wt% or less molybdenum (Mo), 5 wt% or less Cr, 3 wt% or less Cu, 3 wt% or less Ni, 20 wt% or less magnesium (Mg), 0.01-7 wt% aluminum (Al), 13 wt% or less barium (Ba), 0.01-7 wt% calcium (Ca), 12 wt% or less manganese (Mn), 8 wt% or less zirconium (Zr), 12 wt% or less lanthanum (La) and / or cerium (Ce) and / or mischmetal, 5 wt% or less strontium (Sr), 3 wt% or less bismuth (Bi), 3 wt% or less antimony (Sb), 1.5 wt% or less titanium (Ti), the remainder being Fe and associated impurities. A method for producing cast iron, comprising the step of adding FeSiV and / or Nb alloy according to any of the above embodiments.

[0099] The ferrosilicon-based alloy containing vanadium and / or niobium exhibits faster assimilation of vanadium and / or niobium by the molten iron, thus allowing for the use of alloys with potentially lower melting points and different melting pathways further downstream in the cast iron process. A surprising finding was the higher recovery of vanadium and / or niobium compared to conventional solutions. The advantages of adding vanadium and / or niobium after the molten iron is removed from the blast furnace include the possibility of handling smaller amounts of iron and facilitating transitions between grades, avoiding overheating of the molten iron and contamination of the clarification within the blast furnace, and, when added as an element in the inoculant instream, potentially offering greater flexibility in terms of batch size of the alloyed cast iron pieces.

[0100] Ferrosilicon-based alloys containing vanadium and / or niobium can be used as FeSiV or FeSiNbV or FeSiNb and associated impurities as part of a charge in a blast furnace or holding furnace without the need for long waiting times or temperatures exceeding the required temperature downstream of the casting process, or they can be added further downstream in the process. When alloyed with additional elements, ferrosilicon-based vanadium and / or niobium alloys can also be used to alloy molten material in a blast furnace and may be used as a preconditioner, a cover material or agglomerating agent in ladle processing, as a coated or uncoated crushed inoculant, or as an insert. Any kind of ferrosilicon-based vanadium and / or niobium alloy, alloyed with or coated with other elements, or uncoated with other elements, may be used in cored wire mixed with or uncoated with other alloys or elements.

[0101] Another advantage of these alloys is their lower density compared to FeV80 or FeNb65. In fact, denser alloys tend to sink to the bottom of the blast furnace or ladle, leading to segregation in the molten iron if not properly stirred.

[0102] Another advantage of these alloys is that when the addition of vanadium and / or niobium is combined with the addition of other necessary processed alloys, there is one less addition step in the process. [Examples]

[0103] Example 1: Production of a vanadium-containing ferrosilicon alloy Ten molten materials were prepared for the production of the FeSiV alloy according to the present invention. Two divisional alloys were produced. The first divisional alloy was a ferrosilicon vanadium alloy, and the second divisional alloy was a combination of the advantages of the ferrosilicon vanadium alloy and the addition of several elements commonly used to process cast iron molten materials, both according to the present invention. FeSiV was produced as described in the text using vanadium oxide. The other alloys were produced by adding other elements to FeSiV. This was done in two steps. A large batch of FeSiV was produced, placed in a mold, roughly crushed, and remelted for the addition of other elements in smaller batches.

[0104] Table 1 below shows the amounts of FeSi75 (lump form) and V2O5 (powder form) used as raw materials for three test productions of FeSiV. Furthermore, the amount of lime (CaO) used to modify the slag and the total amount of Al in the system are indicated. The temperature (T) was set above the melting point of the FeSiV alloy before the addition of V2O5. The molten ferrosilicon alloy was stirred during the addition of V2O5, lime, and aluminum. The resulting compositions are listed on the right side of the table. Separating the slag from the metal during tapping is important for the purity of the FeSiV alloy produced.

[0105] [Table 1]

[0106] Table 2 below shows the composition of ferrosilicon alloys containing vanadium, along with additional elements commonly used in the treatment of cast iron molten metals. One ferrosilicon vanadium alloy was initially produced according to the method described above, and various elements were alloyed into the molten metal. For simplicity, these ferrosilicon vanadium alloys produced according to the present invention are referred to as "alloys."

[0107] [Table 2]

[0108] Example 2: Comparison of dissolution behavior of FeSiV alloy and FeV80 The dissolution behavior of FeSiV alloys in molten iron at 1400°C and 1500°C was compared with that of FeV80. The concentrations of carbon and silicon in the molten iron were 3.6% by weight and 2.2% by weight, respectively. Dissolution time can be measured by various methods known from the literature. In examples, weight loss was measured by connecting a load cell to the ferroalloy (Gourtsoyannis et al., 1984), or samples of molten cast iron were taken at regular intervals and elemental content was analyzed (Argyropoulus, 1983). Although the method in the reference literature describes the measurement of dissolution time in steel, the same principle can be applied to the measurement of dissolution time in molten iron.

[0109] Refer to Figure 1, which shows the melting time at 1400°C. FeV80 pieces measuring 7-18 mm were monitored for approximately 3 minutes at 1400°C but did not melt at all and are therefore not shown in the figure. Thus, the melting time of FeSiV alloy is much shorter than that of FeV80.

[0110] Refer to Figure 2. Figure 2 shows that the measured dissolution time of FeV80 in lumps smaller than 20 mm is twice as long as that of FeSiV18 (FeSiV containing approximately 18 wt% vanadium). The difference is even greater for larger lumps. 1500°C is the standard temperature when tapping out of the blast furnace, and all subsequent processes are at lower temperatures, between 1300 and 1400°C for the inoculation process.

[0111] Example 3: Vanadium Yield FeSiV alloy was used in the inoculation process during cast iron production. The molten material was heated in an induction oven and treated with a clumping agent before being poured into six injection ladles. The alloy was added to the bottom of the injection ladles before injection. All alloy pieces were broken into the same size, 1–3 mm. The amount of iron poured into each ladle was the same. The temperature of the iron in the clumping ladles immediately before pouring into the injection ladles was 1424°C. The molten material was held in the injection ladles for 1–5 minutes and then poured into sand molds. Castings were taken for chemical analysis using an ArcSpark-OES spectrometer before injection.

[0112] As shown in Table 3, the FeSiV alloy was completely assimilated into the molten material after 1 minute, and all of the vanadium was recovered, while the vanadium recovery rate from FeV80 was 63% after 5 minutes.

[0113] [Table 3]

[0114] Example 4: Production of a ferrosilicon alloy containing niobium Eight molten materials were prepared for the production of the FeSiNb alloy according to the present invention. Two divisional alloys were produced. The first divisional alloy was a ferrosilicon niobium alloy, and the second divisional alloy was a combination of the advantages of the ferrosilicon niobium alloy and the addition of several elements commonly used to process cast iron molten materials, both according to the present invention. FeSiNb was produced as described in the text using niobium oxide. The other alloys were produced by adding other elements to FeSiNb. This was done in two steps. A large batch of FeSiNb was produced, placed in a mold, roughly crushed, and remelted for the addition of other elements in smaller batches.

[0115] Table 4 below shows the amounts of FeSi75 and Nb2O5 (fine powder) used as raw materials for three test fabrications of FeSiNb alloy. Furthermore, the amount of lime (CaO) used to modify the slag and the total amount of Al in the system are indicated. The temperature (T) was set above the melting point of the FeSiNb alloy before the addition of Nb2O5. The molten ferrosilicon alloy was stirred during the addition of Nb2O5, lime, and aluminum. The resulting compositions are listed on the right side of the table. Separating the slag from the metal during tapping is important for the purity of the FeSiNb alloy produced.

[0116] [Table 4]

[0117] Table 5 below shows the composition of ferrosilicon alloys containing niobium, along with additional elements commonly used in the treatment of cast iron molten metals. One ferrosilicon niobium alloy with a target Nb content of 30 wt% was first produced according to the method described above, and various elements were alloyed into the molten metal. For simplicity, these ferrosilicon niobium alloys produced according to the present invention will be referred to as "alloys".

[0118] [Table 5]

[0119] Example 5: Comparison of solubility properties of FeSiNb alloy and FeNb65 The dissolution behavior of FeSiNb alloy in molten iron at 1500°C was compared with that of FeNb65. The concentrations of carbon and silicon in the molten iron were 3.6% by weight and 2.2% by weight, respectively.

[0120] As shown in Figure 3, the melting time of FeSiNb alloy is shorter than that of FeNb65. 1500°C is the standard temperature when tapping the molten metal from the blast furnace, and all subsequent processes are at lower temperatures, between 1300 and 1400°C for the inoculation process. At lower temperatures, the longer melting time of FeNb65 among the various alloys becomes even more apparent.

[0121] Example 6: Yield of Niobium Nb is typically FeNb, and due to its high melting point, it is added to cast iron by being added to the blast furnace. The purpose of using Nb as part of an FeSi alloy is to use an alloy with a lower melting point. This makes later additions in the process easier. This was tested by adding an Nb-containing alloy during the inoculation process in cast iron production. The addition rates of various Nb-containing alloys were adjusted to provide the same amount of Nb relative to the iron, 0.20 wt% in this example. The trials were performed at two temperatures, 1500°C and 1440°C, to check that low yield temperatures were acceptable. A tapping temperature of 1500°C means that the peak melting temperature for the Nb-containing alloy is approximately 1420°C. On the other hand, a tapping temperature of 1440°C means that the peak melting temperature for the Nb-containing alloy is approximately 1350°C. The alloy was added to the bottom of the pouring ladle and held for 1 minute before being placed in the mold. The size of the alloy grains was the same for all pouring ladles in both tests, 1-3 mm.

[0122] Table 6 below shows the results of the trials conducted to investigate the hot water temperature at 1500°C.

[0123] [Table 6]

[0124] The trials were repeated with FeNb, FeSiNb30, and Alloy8 at a lower hot water outlet temperature of 1440°C. The results of the trials are shown in Table 7 below.

[0125] [Table 7]

[0126] As shown in the results in Tables 6 and 7, the FeSi alloy containing Nb yielded significantly higher yields compared to the FeNb alloy. The FeSi alloy-based alloy containing Nb achieved an Nb yield of over 80% at a tapping temperature of 1500°C, while FeNb yielded only 8%. At a lower tapping temperature of 1440°C, the Nb yield of the FeSi alloy containing Nb decreased to approximately 70%, while FeNb achieved a yield of 16%.

[0127] Example 7: Production of a ferrosilicon alloy containing vanadium and niobium, and a ferrosilicon alloy containing niobium, vanadium, and molybdenum. One molten material for the production of the FeSiVNb alloy according to the present invention was prepared. Table 8 below shows the amounts of FeSi75, V2O5, and Nb2O5 as raw materials.

[0128] Furthermore, the amount of lime (CaO) used to modify the slag and the total amount of Al in the system are noted. The temperature (T) was set above the melting point of the FeSiVNb alloy before the addition of V2O5 and Nb2O5. The molten ferrosilicon alloy was stirred during the addition of V2O5, Nb2O5, lime, and aluminum. The resulting composition is listed on the right side of the table. Separating the slag from the metal during tapping is important for the purity of the FeSiVNb alloy produced.

[0129] To obtain the FeSiVNbMo alloy, an additional alloy was prepared by adding FeMo65 in addition to vanadium oxide and niobium oxide. FeMo65 contains 65% by weight of Mo. The amounts of raw materials used in the production and the composition of the FeSiVNbMo alloy are shown in Table 9.

[0130] [Table 8]

[0131] [Table 9]

[0132] Example 8: Comparison of the melting behavior of FeSiNbV alloy and FeSiNbVMo alloy with FeNb65 and FeV80 The dissolution behavior of FeSiNbV alloy and FeSiNbVMo alloy in an iron bath at 1500°C was compared with that of FeNb65 and FeV80. The concentrations of carbon and silicon in the molten iron were 3.6% by weight and 2.2% by weight, respectively. Referring to Figure 4, it is clear that the dissolution times of FeSiNbV and FeSiNbVMo are shorter than those of FeNb65 and FeV80.

[0133] Example 9: Production of FeSiV from FeSiCr / FeSiMn Starting with an FeSi alloy containing 5% by weight of either Mn or Cr, and including Mn and Cr as alloying elements, the result is an FeSiV alloy with the composition shown in Table 10 below.

[0134] [Table 10]

[0135] Further trials were prepared for the production of the FeSiV alloy according to the present invention, using FeSiMn as a raw material. Table 11 below shows the amounts of FeSiMn and V2O5, the raw materials for two prototypes of FeSiV. Furthermore, the amount of lime (CaO) for modifying the slag and the total amount of Al in the system are indicated. The molten alloy was stirred during the addition of V2O5, lime, and aluminum. The compositions produced are shown on the right side of Table 11.

[0136] [Table 11]

[0137] Example 10: Density measurement of the selected alloy Table 12 shows the measured densities of the selected alloys. As can be seen in the table, the density of the FeSiVNb alloy of the present invention is considerably lower than that of FeV80 and FeNb65.

[0138] [Table 12]

[0139] Those skilled in the art should understand that the present invention is not limited to the preferred embodiments described above. They should also understand that modifications and changes are possible within the scope of the appended claims. Furthermore, when carrying out the claimed invention based on the study of the disclosure and the appended claims, modifications to the disclosed embodiments may be understood and made by those skilled in the art.

Claims

1. 15-80 mass% Si, 5 to 35% by mass of V and / or Nb, Mo of 10% by mass or less, 5% by mass or less of Cr, Cu of 3 mass% or less, Ni of 3 mass% or less, Mg of 20% by mass or less, 0.01 to 7 mass% Al, Ba of 13% by mass or less, 0.01 to 7 mass% Ca, Mn, 13% by mass or less 8% by mass or less of Zr, 12% by mass or less of La and / or Ce and / or mischmetal, Sr of 5% by mass or less, 3% by mass or less of Bi, Sb of 3 mass% or less, 1.5% by mass or less of Ti, The remaining Fe, and A ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy, consisting of associated impurities, is an additive used in the production of cast iron.

2. The FeSiV and / or Nb alloy according to claim 1, comprising 15 to 29 mass% Si, 5 to 35 mass% V and / or Nb, 10 mass% or less Mo, 5 mass% or less Cr, 3 mass% or less Cu, 3 mass% or less Ni, 20 mass% or less Mg, 0.01 to 7 mass% Al, 13 mass% or less Ba, 0.01 to 7 mass% Ca, 13 mass% or less Mn, 8 mass% or less Zr, 12 mass% or less La and / or Ce and / or mischmetal, 5 mass% or less Sr, 3 mass% or less Bi, 3 mass% or less Sb, 1.5 mass% or less Ti, the remainder Fe, and associated impurities.

3. The FeSiV and / or Nb alloy according to claim 1, comprising 30 to 50 mass% Si, 16 to 35 mass% V and / or Nb, 10 mass% or less Mo, 5 mass% or less Cr, 3 mass% or less Cu, 3 mass% or less Ni, 20 mass% or less Mg, 0.01 to 7 mass% Al, 13 mass% or less Ba, 0.01 to 7 mass% Ca, 13 mass% or less Mn, 8 mass% or less Zr, 12 mass% or less La and / or Ce and / or mischmetal, 5 mass% or less Sr, 3 mass% or less Bi, 3 mass% or less Sb, 1.5 mass% or less Ti, the remainder Fe, and associated impurities.

4. The FeSiV and / or Nb alloy according to claim 1, comprising 51 to 80 mass% Si, 5 to 35 mass% V and / or Nb, 10 mass% or less Mo, 5 mass% or less Cr, 3 mass% or less Cu, 3 mass% or less Ni, 20 mass% or less Mg, 0.01 to 7 mass% Al, 13 mass% or less Ba, 0.01 to 7 mass% Ca, 13 mass% or less Mn, 8 mass% or less Zr, 12 mass% or less La and / or Ce and / or mischmetal, 5 mass% or less Sr, 3 mass% or less Bi, 3 mass% or less Sb, 1.5 mass% or less Ti, the remainder Fe, and associated impurities.

5. FeSiV and / or Nb alloy according to any one of claims 1 to 4, comprising 15% by mass or less of Mg.

6. FeSiV and / or Nb alloy according to any one of claims 1 to 5, comprising 5% by mass or less of Mo.

7. The FeSiV and / or Nb alloy according to any one of claims 1 to 6, wherein the melting temperature range of the FeSiV and / or Nb alloy is 1060 to 1640°C.

8. The FeSiV and / or Nb alloy according to any one of claims 1 to 7, wherein the FeSiV and / or Nb alloy has the shape of particles or chunks of 0.06 to 50 mm.

9. The FeSiV and / or Nb alloy according to claim 8, wherein the FeSiV and / or Nb alloy particles or chunks are coated or mixed with bismuth oxide and / or bismuth sulfide and / or antimony sulfide and / or antimony oxide and / or iron oxide and / or iron sulfide.

10. A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to any one of claims 1 to 9, A process of supplying molten ferrosilicon alloy, A step of adding a vanadium oxide-containing raw material and / or a niobium oxide-containing raw material to a molten ferrosilicon alloy, wherein the vanadium oxide-containing raw material and / or niobium oxide-containing raw material are added in an amount (by mass) that essentially supplies a target amount (by mass) of the elements vanadium and / or niobium to the FeSiV and / or Nb alloy. A process of mixing molten ferrosilicon alloy with vanadium oxide derived from vanadium oxide-containing raw materials and / or niobium oxide derived from niobium oxide-containing raw materials, and reacting them to form molten FeSiV and / or Nb alloy and slag. A step of separating slag from the molten material, and The process of solidifying molten FeSiV and / or Nb alloy or placing it into a mold, A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy having the following characteristics.

11. A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to claim 10, wherein the molten ferrosilicon alloy is supplied directly from a reducing blast furnace, and the ferrosilicon is as produced from the raw materials by conventional methods.

12. A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to claim 10, wherein the molten ferrosilicon alloy is supplied by remelting a charge of ferrosilicon alloy.

13. The vanadium oxide-containing raw material is one or more vanadium oxide phases selected from vanadium(II) oxide, vanadium(III) oxide, vanadium(IV) oxide, vanadium(V) oxide and / or other non-main axis oxides of vanadium, and / or A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to any one of claims 10 to 12, wherein the niobium oxide-containing raw material is one or more niobium oxide phases selected from niobium(II) oxide, niobium(III) oxide, niobium(IV) oxide, niobium(V) oxide and / or other non-core oxides of niobium.

14. The vanadium oxide phase consists of vanadium(V) oxide and V ２ O ５ and / or vanadium(III) oxide, V ２ O ３ is, and / or The niobium oxide phase consists of niobium(V) oxide and Nb ２ O ５ and / or niobium(III) oxide, Nb ２ O ３ The method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to claim 13.

15. The vanadium oxide-containing raw materials further include industrial waste materials or ores containing vanadium oxide, and / or A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to claim 13 or 14, wherein the niobium oxide-containing raw material further comprises industrial waste material or ore containing niobium oxide.

16. A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to any one of claims 10 to 15, wherein a compound for modifying slag is added to the molten ferrosilicon alloy in an amount of 0.5 to 30% by mass relative to the total amount of the ferrosilicon alloy and vanadium oxide and / or niobium oxide.

17. A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to claim 16, wherein the compound for modifying the slag is at least one of CaO and MgO.

18. Melt-start ferrosilicon alloys are, 40-90% by mass of Si, C of 0.5% by mass or less, 0.01 to 7 mass% Al, Ca 6% by mass or less, 1.5% by mass or less of Ti, Mn, 15% by mass or less 10% by mass or less of Cr, 10% by mass or less of Zr, Ba of 15% by mass or less, P is 0.3% by mass or less. S is 0.5% by mass or less. The remaining Fe, and A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to any one of claims 10 to 17, comprising associated impurities.

19. The method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to any one of claims 10 to 18, further comprising the step of adding aluminum to the ferrosilicon molten material in an amount of 10% by mass or less relative to the total amount of the ferrosilicon alloy and vanadium oxide and / or niobium oxide, either simultaneously with or after the addition of the vanadium oxide-containing raw material and / or niobium oxide-containing raw material.

20. A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to any one of claims 10 to 19, wherein a molten ferrosilicon alloy, a vanadium oxide-containing raw material and / or a niobium oxide-containing raw material, and a compound for modifying added aluminum and / or slag are mixed by mechanical stirring or gas stirring.

21. A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to any one of claims 10 to 20, wherein the slag is separated before or during the process of placing the molten ferrosilicon-vanadium-and / or niobium alloy into a mold.

22. A method for producing a ferrosilicon-vanadium-and / or niobium (FeSiV and / or Nb) alloy according to any one of claims 10 to 21, wherein the FeSiV and / or Nb alloy is placed in a mold and solidified, forming a block, or is crushed and optionally graded into size fractions, or aggregated.

23. Use of the FeSiV and / or Nb alloy according to any one of claims 1 to 9 as an additive in the production of vanadium and / or niobium-containing cast iron.

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