JP2010229525A - Method for producing ferronickel and ferrovanadium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for highly efficiently and inexpensively producing ferronickel and ferrovanadium from petroleum base combustion ash including NiO, V<SB>2</SB>O<SB>5</SB>and Fe<SB>2</SB>O<SB>3</SB>, individually. <P>SOLUTION: The method comprises: a mixing stage S1 where petroleum base combustion ash including NiO, V<SB>2</SB>O<SB>5</SB>and Fe<SB>2</SB>O<SB>3</SB>, a carbonaceous reducing agent and a slag forming agent are mixed so as to obtain a mixture; a ferronickel production stage S2 where the mixture is melted at 1,350 to 1,550°C so as to be a melt, and ferronickel is produced into the melt; a ferronickel separation stage S3 where the melt to which the ferronickel is flocculated is cooled, and is thereafter separated into the ferronickel and V<SB>2</SB>O<SB>5</SB>-containing slag; a ferrovanadium production stage S4 where the V<SB>2</SB>O<SB>5</SB>-containing slag and an iron source are mixed, the mixture is melted at ≥1,500°C, thereafter, a metal reducing agent is addded thereto so as to be a re-melted matter, and the ferrovanadium is produced in the re-melted matter; and a ferrovanadium separation stage S5 where the re-melted matter in which the ferrovanadium is produced is separated into the ferrovanadium and slag. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing ferronickel and ferrovanadium for producing ferronickel and ferrovanadium from petroleum-based combustion ash containing nickel oxide and vanadium oxide.

Conventionally, as a manufacturing method of alloy iron containing vanadium, that is, ferrovanadium, there are mainly a thermite method and an electric furnace method, and the thermite method is currently used as a main manufacturing method.
Here, the raw material for producing ferrovanadium is vanadium pentoxide extracted from titanium-containing vanadium magnetite and the like. To obtain this vanadium pentoxide, first, coke and limestone are mixed with titanium-containing vanadium magnetite, and then the rotary kiln is used. Preliminarily reduced and reduced in an electric smelting furnace to produce pig iron containing vanadium. Then, after oxidative refining, slag containing vanadium is mixed with sodium carbonate or sodium chloride and oxidative roasted, and then water is added to obtain a sodium vanadate solution. Then, a pH adjusting agent and ammonium chloride are further added to obtain ammonium vanadate, followed by drying and melting to obtain vanadium pentoxide.

  In the method for producing ferrovanadium by the thermite method, for example, a mixture of a reducing agent such as vanadium oxide, iron source, ferrosilicon powder and aluminum particles and a medium solvent such as iron ore and mill scale is mixed to form a mixture. A technique for producing ferrovanadium using a reaction furnace has been proposed (see Non-Patent Document 1).

  At present, the electric furnace method is not widely used, but in the ferrovanadium production method using the electric furnace method, a vanadium raw material such as vanadium ore, an iron source, a reducing agent and a solvent are mixed to form a mixture, and an electric furnace is used. To produce ferrovanadium. Here, it has been proposed to use a reducing agent such as ferrosilicon or aluminum when reducing to give a slight vibration to separate the slag (see Patent Document 1).

  On the other hand, a method of producing alloy iron (Fe—Ni—V alloy) containing vanadium and nickel from petroleum combustion ash containing nickel and vanadium has also been proposed. For example, petroleum combustion ash is reduced with ferrosilicon or aluminum in a melting furnace to obtain Ni-V alloy iron (see Patent Document 2), petroleum combustion ash is pulverized and heated in a cyclone, and then further ferro There has been proposed a method of obtaining iron (Fe—Ni—Mo—V alloy) containing nickel, molybdenum and vanadium by reduction with silicon or aluminum (see Patent Document 3).

  Also, petroleum-based combustion ash, reducing agent, and iron source are mixed, formed into briquettes, etc. if necessary, reduced at 1150 ° C to 1350 ° C, and the mixture or molded product is mounted in a furnace bottom steel electric furnace. A method of energizing and melting is proposed (see Patent Document 4). In this method, nickel and molybdenum contents in petroleum-based combustion ash are preferentially reduced by an iron source such as carbon in the combustion ash and separately charged scrap, and alloy iron containing nickel and vanadium (Fe-Ni-Mo alloy). ) And alloy iron (Fe-V alloy (ferrovanadium)) containing vanadium can be obtained by reducing the recovered slag.

Edited by Japan Iron and Steel Institute, Steel Handbook, 3rd edition, Volume 2, Issued by: Japan Iron and Steel Institute, issued July 30, 2002, Chapter 7 Section 3 Section 5

JP 54-46116 A JP 2001-316732 A JP 2001-98339 A JP 2004-270036 A

  However, the methods for producing alloy iron described in Non-Patent Document 1 and Patent Documents 1 to 4 have the following problems.

  In the thermite method described in Non-Patent Document 1, it is pointed out that the cooling and crushing treatment of ferrovanadium after the thermite reaction is expensive, and there is a problem that it is inferior in economic efficiency. In addition, rotary kilns generate a large amount of dust, and dam rings are likely to occur in the kiln, and the residence time of raw materials varies, requiring an excessive length of the processing conveyance path, and the installation area of the equipment is large. There are also problems such as an increase in the surface area of the kiln and a large amount of heat dissipation, resulting in an increase in fuel consumption.

  In the electric furnace method described in Patent Document 1, it is necessary to use expensive ferrosilicon or aluminum for reduction and to melt the ferrovanadium to be obtained. There is a problem that becomes high.

Further, in the production methods described in Non-Patent Document 1 and Patent Document 1, since vanadium ore or the like is used as a raw material, there is a problem that it is inferior in economic efficiency due to a recent rise in vanadium ore.
In the manufacturing method described in Patent Document 2, since expensive ferrosilicon or aluminum is used for reduction, there is a problem that the manufacturing cost increases.

In the production method described in Patent Document 3, a petroleum-based combustion ash is charged into a cyclone, heated and dissolved, and then charged into a reaction furnace together with a reducing agent to obtain an iron alloy by reducing metal components. It is. Moreover, in the manufacturing method of patent document 4, after reducing a raw material, it melt | dissolves and reduces the collect | recovered slag and obtains alloy iron.
Therefore, the manufacturing methods described in Patent Document 3 and Patent Document 4 have a problem that the process is complicated and the cost is inferior.

  The present invention has been made in view of the above problems, and its object is to produce ferronickel and ferrovanadium individually and highly efficiently and inexpensively from petroleum combustion ash containing nickel oxide, vanadium oxide and iron oxide. Another object of the present invention is to provide a process for producing ferronickel and ferrovanadium.

  As a result of intensive studies to solve the above problems, the present inventors have added a carbonaceous reducing agent to petroleum-based combustion ash, and melted it twice at different specific temperature ranges to obtain ferronickel and ferro It has been found that vanadium can be produced individually and with high efficiency and at low cost, and the present invention has been completed.

  The method for producing ferronickel and ferrovanadium according to claim 1 is a method for producing ferronickel and ferrovanadium for producing ferronickel and ferrovanadium from petroleum combustion ash, and includes nickel oxide, vanadium oxide and iron oxide. A mixing step of mixing a petroleum-based combustion ash, a carbonaceous reducing agent, and a slag forming agent to obtain a mixture, and the mixture mixed in the mixing step is heated and melted at 1350 to 1550 ° C. to obtain a melt. A ferronickel production step for aggregating the ferronickel produced therein, a ferronickel separation step for separating the ferronickel and the vanadium oxide-containing slag after cooling the melt agglomerated the ferronickel, Mix the vanadium oxide-containing slag and iron source and heat at 1500 ° C or higher After melting, a metal reducing agent is added to form a remelt, a ferrovanadium production step for producing ferrovanadium in the remelt, and a remelt for producing the ferrovanadium, the ferrovanadium and slag And a ferrovanadium separation step of separating the ferrovanadium.

According to such a manufacturing method, nickel oxide (NiO) and iron oxide (Fe ₂ O ₃ ) in the mixture mixed in the mixing step are melted in a specific temperature range of 1350 to 1550 ° C. in the ferronickel generation step. Thus, a reduction reaction occurs due to carbon (C) contained in the carbonaceous reducing agent in the mixture. One example is shown in the following formula (1).
Fe ₂ O ₃ + NiO + 4C → 2Fe + Ni + 4CO (1)
That is, iron oxide and nickel oxide are once converted into metallic iron and metallic nickel by carbon, and then further reacted with carbon to produce ferronickel (Fe—Ni alloy). Since the vanadium oxide-containing slag (V ₂ O ₅ -containing slag) produced in the ferronickel production process melts into a liquid or soft body in the temperature range of 1350 to 1550 ° C., the produced ferronickel aggregates in granular form. can do. Therefore, after cooling in the ferronickel separation step, by separating them by applying a physical impact or the like, only ferronickel can be obtained without lowering the yield.

The vanadium oxide (V ₂ O ₅ ) contained in the melt remains in the slag without being reduced by the reduction reaction of the formula (1). However, after the iron source is mixed and melted at a specific temperature of 1500 ° C. or higher in the next ferrovanadium production step, the reduction reaction can be performed by adding a metal reducing agent. One example is shown in the following equation (2). Thereby, vanadium oxide can be obtained as ferrovanadium (Fe-V alloy). In the following formula (2), Al is used as the metal reducing agent, and the iron supplied as the iron source is not iron oxide.
Fe + 3V ₂ O ₅ + 10Al → Fe + 6V + 5Al ₂ O ₃ (2)
The produced ferrovanadium and the slag produced here are in a molten state, that is, liquid at 1500 ° C. or higher, and the ferrovanadium is separated into the lower layer and the slag is separated into the upper layer due to the difference in specific gravity. Yes. Therefore, only ferrovanadium can be obtained by separating them into two in the ferrovanadium separation step.

The method for producing ferronickel and ferrovanadium according to claim 2 uses at least one of a CaO supply substance and a SiO ₂ supply substance as the slag forming agent, and a ratio of CaO and SiO ₂ in the mixture (CaO / SiO ₂ ) in a mass ratio of 0.2 to 1.65.
With such a manufacturing method, the slag can be reliably melted even when the temperature is low in the ferronickel production step. Moreover, it can prevent that the sulfur (S) contained in petroleum combustion ash transfers to ferronickel.

In the method for producing ferronickel and ferrovanadium according to claim 3, the ratio (C / O) between the amount of carbon in the mixture and the amount of oxygen contained in the iron oxide and nickel oxide is 1 or more in molar ratio. In addition, the carbonaceous reducing agent is blended so that carbon contained in the carbonaceous reducing agent remains in an amount of 6% by mass or less in the produced ferronickel.
With such a manufacturing method, the reduction reaction of iron oxide and nickel oxide can be sufficiently performed in the ferronickel production step. In addition, since carbon is carburized in the produced ferronickel, even when a holding container using a carbonaceous material is used in the ferronickel production process, the carbon in the holding container reacts and the holding container is melted. Can be prevented.

The method for producing ferronickel and ferrovanadium according to claim 4 is characterized in that at least one of calcium carbonate, quicklime and slaked lime is used as the CaO supply substance.
If it is such a manufacturing method, CaO can be efficiently supplied by using at least 1 sort (s) of calcium carbonate, quicklime, and slaked lime as a CaO supply substance.

The method for producing ferronickel and ferrovanadium according to claim 5 is characterized in that a molded body of a carbonaceous material is used as a holding container for melting the mixture in the ferronickel production step.
With such a manufacturing method, it becomes easy to take out the slag from the holding container.

The method for producing ferronickel and ferrovanadium according to claim 6 is characterized in that, in the ferronickel production step, a rotary hearth furnace is used to melt the mixture.
With such a manufacturing method, since the rotary hearth furnace is used, ferronickel can be manufactured more efficiently.

In the method for producing ferronickel and ferrovanadium according to claim 7, in the ferronickel production step, before charging the mixture onto the hearth of the rotary hearth furnace, carbonaceous powder is spread on the hearth. It is characterized by leaving.
With such a manufacturing method, the inside of the furnace can be maintained at a high reduction potential by the carbonaceous powder laid on the hearth, so that the metallization rate can be further increased. Moreover, the refractory material used for the hearth can be prevented from being melted.

The method for producing ferronickel and ferrovanadium according to claim 8 is characterized in that the carbonaceous powder is laid on the hearth with a thickness of 2 mm or more.
With such a manufacturing method, it is possible to reliably obtain the effect of placing the carbonaceous powder on the hearth.

The method for producing ferronickel and ferrovanadium according to claim 9 is characterized in that the metal reducing agent is at least one of Al and Fe-Si alloys.
With such a production method, since at least one of Al and Fe—Si alloys is used as the metal reducing agent, iron oxide and vanadium oxide can be reliably reduced.

In the method for producing ferronickel and ferrovanadium according to claim 10, when Al is used as the metal reducing agent, the Al is contained in a mass ratio of 0.5 to the amount of vanadium oxide contained in the vanadium oxide-containing slag. It is characterized by adding so that it becomes.
With such a production method, when Al is used as the metal reducing agent, Al is added so that the mass ratio is 0.5 with respect to the amount of vanadium oxide contained in the vanadium oxide-containing slag. In addition, the entire amount of vanadium oxide can be reduced. In addition, it is possible to prevent expensive Al from being added excessively or excess Al from being mixed into ferrovanadium.

  According to the invention which concerns on Claim 1, by making each melting temperature in a ferronickel production | generation process and a ferrovanadium production | generation process into a specific range, ferronickel and vanadium oxide containing slag, and ferrovanadium and slag can be isolate | separated, respectively. Therefore, ferronickel and ferrovanadium can be manufactured individually with high efficiency and at low cost.

According to the invention of claim 2, the slag can be reliably melted, the transition of sulfur to ferronickel can be prevented, and the S concentration in ferronickel can be suppressed. High ferronickel can be obtained.
According to the invention which concerns on Claim 3, since the reduction reaction of iron oxide and nickel oxide can fully be performed, ferronickel can be obtained with a high yield.
According to the invention which concerns on Claim 4, since at least 1 sort (s) of calcium carbonate, quicklime, and slaked lime is used, CaO can be supplied efficiently. Further, ferronickel can be produced at low cost.

According to the fifth aspect of the present invention, since the rotary hearth furnace is used, ferronickel can be manufactured more efficiently. Therefore, ferronickel can be manufactured at a lower cost.
According to the invention of claim 6, ferronickel can be easily taken out from the holding container.
According to the invention which concerns on Claim 7, since a metallization rate can be raised further, the purity (recovery rate) of ferronickel can be improved. Moreover, since the refractory material used for the hearth can be prevented from being melted, ferronickel can be manufactured at a lower cost.
According to the eighth aspect of the present invention, the effect of placing the carbonaceous powder on the hearth can be reliably obtained, so that the purity can be further improved and ferronickel can be manufactured at a lower cost. be able to.

According to the invention concerning Claim 9, since vanadium oxide can be reduced reliably, ferrovanadium can be obtained with high purity.
According to the invention of claim 10, vanadium oxide can be reduced in its entirety, and excess Al can be prevented from being mixed into ferrovanadium, so that ferrovanadium can be produced with higher purity. can do. Moreover, since it can prevent adding expensive Al too much, ferrovanadium can be manufactured more cheaply.

It is a figure which shows the flow of the manufacturing method of the ferronickel and ferrovanadium which concern on this invention. It is a figure which shows the flow of the substance in each process of the manufacturing method of the ferronickel and ferrovanadium which concern on this invention. It is a schematic diagram which shows a rotary hearth type heating reduction furnace typically.

Next, a method for producing ferronickel and ferrovanadium according to the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the method for producing ferronickel and ferrovanadium according to the present invention comprises a mixing step S1, a ferronickel production step S2, a ferronickel separation step S3, a ferrovanadium production step S4, and a ferrovanadium separation. Step S5 is included.

As shown in FIGS. 1 and 2, the mixing step S1 is a step of obtaining a mixture by mixing petroleum combustion ash, a carbonaceous reducing agent, and a slag forming agent. Here, an example of the composition of petroleum-based combustion ash is shown in Table 1 below. As shown in Table 1, petroleum-based combustion ash is composed of nickel oxide (NiO), vanadium oxide (V ₂ O ₅ ), iron oxide (Fe ₂ O ₃ ), silicon dioxide (SiO ₂ ), oxidation as other substances. It contains calcium (CaO), alumina (Al ₂ O ₃ ), magnesium oxide (MgO), sulfur (S), carbon (C), moisture and impurities.
The present invention, each individual ferroalloy petroleum combustion ashes Including NiO and V ₂ O ₅ and having such composition state, i.e., ferro-nickel (Fe-Ni alloy) and ferrovanadium (Fe-V alloy ) And other materials are discarded as slag or exhaust gas.

  As shown in Table 1, petroleum-based combustion ash may contain a lot of moisture. In such a case, it is preferable to dry the ash before mixing in the mixing step S1. The degree of drying may be appropriately determined in consideration of the granulation properties by the granulator shown in FIG. 2, for example, after the amount of water contained in the petroleum-based combustion ash is 10% by mass or less, Can be granulated.

The carbonaceous reducing agent reduces Fe ₂ O ₃ and NiO. Any carbonaceous reducing agent may be used as long as it contains fixed carbon, and coal, coke, charcoal, waste toner, biomass carbide, and the like can be used. Of course, a mixture of these may be used.
The compounding ratio of the carbonaceous reducing agent in the mixture is such that the ratio (C / O) between the amount of carbon (C) in the mixture and the amount of oxygen (O) contained in Fe ₂ O ₃ and NiO is 1 or more in molar ratio. In addition, it is preferable that the carbonaceous reducing agent is blended so that the carbon contained in the ferronickel is 6 mass% or less (including 0 mass%), preferably 0.2 mass% or less. When the molar ratio of C / O is 1 or more, Fe ₂ O ₃ and NiO contained in petroleum-based combustion ash are reduced to produce metal Fe and metal Ni, thereby producing ferronickel. become able to. Details will be described in the ferronickel production step described later.

When a carbonaceous reducing agent is used, carbon is carburized into the produced ferronickel, so that the melting point as a metal is lowered, and the produced ferronickel is likely to aggregate. Therefore, ferronickel having a high nickel concentration can be obtained even at a relatively low temperature. In addition, since C is already present in ferronickel, even if the holding container is formed of a carbonaceous material in the ferronickel production process described later, C in the holding container is nickel oxide or ferronickel. No reaction occurs, and it is possible to prevent melting of the holding container. Therefore, it is preferable that C / O be 1 or more in molar ratio as described above. When C / O is less than 1 in terms of molar ratio, the effects described above cannot be obtained sufficiently. Further, since C is too small, not only Fe ₂ O ₃ and NiO are hardly reduced, but also the melting point of ferronickel is hardly lowered, so that the yield of ferromolybdenum tends to be deteriorated. Accordingly, the carbonaceous reducing agent is preferably blended so that it remains in an amount of 6% by mass or less in the produced ferronickel.

The slag forming agent is blended to form slag and immobilize S in the slag. As the slag forming agent, at least one of a CaO supply substance and a SiO ₂ supply substance can be used.

As the CaO supply substance, for example, at least one of calcium carbonate (lime) and quicklime can be used. However, the CaO supply substance is not limited to these, and may be a substance that can supply CaO into the mixture. Anything can be used. For example, slaked lime can also be used. If the CaO supply substance contains impurities other than SiO ₂ , the blending amount may be determined in consideration of the CaO content.

As the SiO ₂ supply substance, for example, silica or silica can be used, but is not limited thereto, and any substance can be used as long as it can supply SiO ₂ into the mixture. Can be used. For example, Wollastitenite can also be used. Wollastenite is a mineral containing both SiO ₂ and CaO. In addition, when using these, it is good to use, after grind | pulverizing so that it may become about 100 micrometers or less.

Here, when coke or the like is used as the carbon reducing agent, CaO or SiO ₂ may be included as impurities. Further, when calcium carbonate or the like is used as the CaO supply substance, SiO ₂ can be contained as an impurity. Furthermore, when Wollastite or the like is used as the SiO ₂ supply material, CaO or SiO ₂ can be contained as impurities.
The amount of CaO and SiO ₂ contained as impurities in the carbon reducing agent, CaO supply substance and SiO ₂ supply substance is very small, but the ratio of CaO and SiO ₂ in the mixture including these (CaO / SiO ₂ ) is in mass ratio. It is desirable to be 0.2 to 1.65.

When CaO / SiO ₂ is less than 0.2 in terms of mass ratio, it is not preferable because S is difficult to fix in slag, and the melting point of slag rises and the mixture is difficult to melt. On the other hand, the larger the CaO / SiO ₂ mass ratio, the greater the ability to fix S, which is preferable. However, if it exceeds 1.65, the melting point of the slag rises as in the case of less than 0.2, and the mixture becomes It is not preferable because it is difficult to melt.

  As shown in FIG. 2, it is preferable to use a mixer in order to obtain a mixture of the petroleum-based combustion ash, the carbonaceous reducing agent, and the slag former in the mixing step S1. As the mixer, for example, a screw mixer or the like can be used. When these mixers are used, a uniform mixture can be obtained quickly, easily and reliably.

Moreover, as shown in FIG. 2, in mixing process S1, after obtaining a mixture, it is preferable to agglomerate with a granulator. By agglomerating the mixture, the amount of dust generated from the heating furnace is reduced, and the CO gas generated as a result of the reaction inside the mixture in the heating furnace is easily moved. Therefore, it is possible to prevent the mixture from becoming dust by this CO gas. As the granulator, for example, a compression molding machine such as a briquette press, a rolling granulator such as a pan pelletizer, and an extrusion molding machine can be used. Needless to say, it is not necessary to agglomerate with a granulator, and moisture may be added when the mixture is too dry for agglomeration with a granulator.
Moreover, when a lot of moisture is contained in the agglomerated mixture, it may be dried before charging into the heating furnace.

Next, as shown in FIGS. 1 and 2, the ferronickel production step S2 is performed by heating and melting the mixture mixed in the mixing step S1 at 1350 to 1550 ° C. to form a melt, and the ferronickel produced in the melt. This is a step of aggregating nickel. Since the carbonaceous reducing agent is contained in the mixture, Fe ₂ O ₃ and NiO can be reduced to metal Fe and metal Ni by heating to 1350 to 1550 ° C. and melting. The heating of the mixture is preferably performed by using a moving hearth furnace such as a rotary hearth furnace (RHF), a linear furnace, a multi-stage furnace, etc., because the mixture to be heated is allowed to stand on the hearth and the generation of dust and the like is small. Among them, RHF is particularly preferable because it is compact and can save facility cost and installation area compared to a rotary kiln or the like. The heating of the mixture is not limited to these, and can be performed using a furnace equipped with a crucible such as an electric furnace, a resistance heating furnace, an induction heating furnace or the like.

An example of the reduction reaction of Fe ₂ O ₃ and NiO generated by heating and melting the mixture to 1350 to 1550 ° C. in the ferronickel production step S2 is shown in the following formula (1). Note that V ₂ O ₅ contained in the petroleum-based combustion ash is not reduced by the reduction reaction of the following formula (1) but remains in the slag (V ₂ O ₅ -containing slag). V ₂ O ₅ remaining in the slag is reduced in a ferrovanadium production step S4 described later. Details will be described in the ferrovanadium generation step S4.
Fe ₂ O ₃ + NiO + 4C → 2Fe + Ni + 4CO (1)
As shown in the formula (1), Fe ₂ O ₃ and NiO are once converted to metal Fe and metal Ni by C. Thereafter, the Fe—Ni alloy containing C can be produced without further reducing the yield by further reacting with C.

Here, when the temperature of the ferronickel production step S2 is less than 1350 ° C., the mixture cannot be melted. On the other hand, if the temperature of the ferronickel production step S2 exceeds 1550 ° C., vanadium oxide may be melted, which is not preferable from the viewpoint of the purity of ferronickel and the yield of ferrovanadium produced later. Further, when using an electric furnace or the like that requires a holding container for holding the mixture during heating when melting the mixture, a molded body of carbonaceous material is used to easily take out the molten material from the holding container. Although it is necessary to use it, when the temperature exceeds 1550 ° C., the produced ferronickel may react with C in the holding container to increase the concentration of C contained in the ferronickel. Furthermore, the slag forming agent when containing SiO ₂ is, SiO ₂ is the heating temperature is included in the V ₂ O ₅ containing slag to coexist with high and ferronickel, are reduced with carbon in the holding vessel. As a result, Si is retained in ferronickel, and the Si concentration of ferronickel is increased. In addition to these, it is not preferable from the viewpoint of preventing an increase in the amount of electric power used, and even when a carbonaceous holding container is used, the holding container is dissolved by C reacting with the holding container. This prevents the holding container from being worn (melted). Therefore, as described above, the heating temperature (maximum reached temperature) of the mixture in the ferronickel production step S2 is set to a range of 1350 to 1550 ° C.

  The ferronickel produced in the ferronickel production step S2 is produced as ferronickel particles in the molten slag, and at the heating temperature in the above range, the ferronickel particles are solid or liquid. For this reason, while being held at the heating temperature in the above-mentioned range, the ferronickel particles coagulate while coexisting with the molten slag, and the ferronickel becomes a lump and the slag and ferrovanadium are physically separated. It becomes a state. When a moving hearth furnace such as RHF is used, the hearth is moved. When a heating furnace such as an electric furnace using a holding container is used, the melt is kept in the holding container for a predetermined time. By holding, the produced ferronickel can be aggregated. In general, when laminating and charging in a carbonaceous holding container at a heating temperature in the range described above, aggregation of ferronickel generated by holding for 1 to 5 minutes is sufficient for 30 minutes to 1 hour when treating with RHF, etc. Can be done.

Incidentally, if not melted at the heating temperature in the range of slag containing V ₂ O ₅ which ferronickel is produced at the same time as that generated (V ₂ O ₅ containing slag) is described above, the generated ferronickel is Care must be taken that the slag containing V ₂ O ₅ melts because it cannot agglomerate. For example, raising the heating temperature as much as possible within a range not exceeding 1550 ° C., by or added as much as possible within a range not exceeding 6% by weight in ferronickel a carbonaceous reducing agent, to produce, V ₂ It is possible to promote melting of the O ₅ -containing slag.

Here, the case where a rotary hearth furnace (RHF) is used as a heating furnace used in the ferronickel production | generation process S2 is demonstrated lightly.
As shown in FIG. 3, in the RHF 10, first, the mixture mixed in the mixing step S <b> 1 is continuously charged onto the rotary hearth 2 through the raw material charging hopper 1. Prior to charging the mixture, carbonaceous powder may be spread on the rotary hearth 2 from the raw material charging hopper 1 and the mixture may be charged thereon. When a holding container is not used as in the RHF 10, it is preferable to use a refractory material for the rotary hearth 2, spread a carbonaceous powder thereon, charge the mixture, and heat. If it does in this way, it can prevent that a refractory material melts down and can also raise a metalization rate further. In this case, the carbonaceous powder is preferably laid on the hearth with a thickness of 2 mm or more. By making the thickness of the carbonaceous powder 2 mm or more, the above-mentioned effect is easily exhibited. On the other hand, if the thickness of the carbonaceous powder is too thick, it becomes difficult to charge the mixture onto the rotary hearth 2 and the effect is saturated.

  The rotary hearth 2 shown in FIG. 3 rotates in a counterclockwise direction and normally makes one turn in about 8 to 16 minutes, although it varies depending on the operating conditions. A plurality of combustion burners 3 are provided on at least one of the upper side wall and the ceiling of the rotary hearth 2, and the hearth is generated by the combustion heat of the combustion burner 3 burned by supplying fuel or the radiant heat thereof. Heat is supplied to the part.

The mixture charged on the rotary hearth 2 composed of the refractory material is heated by the combustion heat and radiant heat from the combustion burner 3 when moving in the circumferential direction in the RHF 10 on the rotary hearth 2, While passing through the heating zone in the RHF 10, Fe ₂ O ₃ and NiO in the mixture are reduced to coexist with slag (V ₂ O ₅ -containing slag) generated together with metal Fe and metal Ni, and the mixture While receiving the carburization from the carbonaceous reducing agent remaining inside, it softens while agglomerating on the grains to form ferronickel particles, and the ferronickel mass and the V ₂ O ₅ -containing slag are in close contact with each other (reduction solidification) Thing) It becomes 4. In addition, the heating temperature in RHF10 shall be 1350-1550 degreeC as above-mentioned.

The generated metal lump 4 is cooled and solidified in the downstream zone of the RHF 10 and then discharged from the rotary hearth 2 to the discharge hopper 6 by a discharge device 5 such as a screw. In addition, you may cool after discharging | emitting from the rotary hearth 2 to the discharge hopper 6. FIG. The metal lump 4 composed of ferronickel and V ₂ O ₅ containing slag thus produced is separated into ferronickel and V ₂ O ₅ containing slag in a ferronickel separation step S3 as will be described later. Note that exhaust gas such as CO and water vapor generated in the RHF 10 is exhausted from the exhaust gas duct 7.

The ferronickel separation step S3 to be performed next is a step of separating the ferronickel and V ₂ O ₅ -containing slag after cooling the melt obtained by agglomerating ferronickel as shown in FIGS. In addition, the cooling of the metal mass 4 produced | generated by reduction | reduction should just reduce to the temperature which the metal mass 4 can maintain solid. This is because the V ₂ O ₅ -containing slag is melted again in the next ferrovanadium production step S4, so that a higher temperature is advantageous in terms of production efficiency and cost. When the RHF 10 is used, the metal lump 4 can be cooled by a cooling mechanism provided in the furnace. Moreover, when using the heating furnace which uses a holding container, it can carry out by hold | maintaining the metal lump 4 in a holding container for a predetermined time.

The cooled metal lump 4 is discharged from the rotary hearth 2 to the discharge hopper 6 by the discharge device 5 as shown in FIG. The discharged metal lump 4 is then crushed by a crusher and separated into ferronickel and V ₂ O ₅ -containing slag substantially free of Ni as shown in FIG. The separated ferronickel and V ₂ O ₅ -containing slag can be obtained separately by being passed through a sieve (screen).

The obtained V ₂ O ₅ -containing slag can be separated from the V ₂ O ₅ -containing slag and the carbonaceous powder adhering thereto by applying it to a screen with a finer mesh opening. The carbonaceous powder separated here is used by being laid again on the hearth of the RHF 10 used in the ferronickel production step S2. The V ₂ O ₅ -containing slag applied to the screen is supplied to the next ferrovanadium production step S4. The obtained V ₂ O ₅ -containing slag can recover the metal content by means such as magnetic separation or flotation.

In the next ferrovanadium production step S4, as shown in FIGS. 1 and 2, the separated V ₂ O ₅ -containing slag and the iron source are mixed and heated and heated at 1500 ° C. or higher in a heating furnace, In this step, a metal reducing agent is added to form a remelt, and ferrovanadium is generated in the remelt. In the ferrovanadium production step S4, it is desirable to use a heating furnace capable of adjusting the atmosphere to be advantageous for reduction. For example, an induction heating furnace having a chamber can be suitably used. For example, by setting the inside of the heating furnace to a nitrogen gas atmosphere or an argon gas atmosphere, it is possible to prevent the added Al from reacting with the air, and thus it is possible to prevent a reduction in reduction efficiency.

  Any iron source can be used as long as it can supply Fe. For example, iron scrap, iron scrap generated during product manufacture, iron oxide, or the like can be used. In addition, it is preferable to use what is not iron oxide from a viewpoint of reducing the addition amount of a metal reducing agent.

As the metal reducing agent, at least one of Al and Fe—Si alloys can be used, but is not limited thereto, and any metal reducing agent can be used as long as it can reduce V ₂ O ₅ and oxidized iron. Even things can be used. However, Al is preferably used from the viewpoint of reducing power and preventing increase in Si concentration of ferrovanadium.
When Al is used as the metal reducing agent is preferably added in an amount of 0.5 at a mass ratio of Al with respect to V ₂ O ₅ content in the V ₂ O ₅ containing slag. This is because the entire amount of vanadium oxide can be reduced. When the mass ratio is less than 0.5, there is a possibility that the reduction reaction of V ₂ O ₅ may not be sufficiently performed, and the recovery rate of ferrovanadium is lowered, which is not preferable. Moreover, when this mass ratio exceeds 0.5, since excess Al mixes in ferrovanadium, there exists a possibility that the purity of ferrovanadium may become low. Furthermore, since expensive Al is added too much, it is not preferable in terms of cost.

An example of the reduction reaction generated by heating and melting the V ₂ O ₅ -containing slag to 1500 ° C. or higher in the ferrovanadium generation step S4 is shown in the following formulas (2) and (3). Note that the following reduction reaction varies depending on the state of iron supplied as an iron source. The following formula (2) is an example when the iron supplied as the iron source is not iron oxide, and the following formula (3) is when the iron supplied as the iron source is iron oxide (Fe ₂ O ₃ ). It is an example.
Fe + 3V ₂ O ₅ + 10Al → Fe + 6V + 5Al ₂ O ₃ (2)
Fe ₂ O ₃ + 3V ₂ O ₅ + 12Al → 2Fe + 6V + 6Al ₂ O ₃ (3)
As shown in the equations (2) and (3), V ₂ O ₅ and Fe ₂ O ₃ are once converted to metal V and metal Fe by C. Thereafter, the Fe—V alloy containing C can be produced without further reducing the yield by further reacting with C.

Here, when the temperature of the ferrovanadium production step S4 is less than 1500 ° C., the V ₂ O ₅ -containing slag cannot be melted to cause a reduction reaction. Moreover, when the temperature of ferrovanadium production | generation process S4 exceeds 1700 degreeC, it may react with C of the holding container which consists of the produced | generated ferrovanadium and the molding of a carbonaceous material, and there exists a possibility that the C density | concentration contained in ferrovanadium may become high. Is not preferable. Furthermore, it is not preferable from the viewpoint of preventing an increase in the amount of power used, and even when a carbonaceous holding container is used, the C of the holding container reacts and wears (melts). This is not preferable. Therefore, as described above, the heating temperature (maximum temperature reached) of the remelt in the ferrovanadium generation step S4 is 1500 ° C. or higher, more preferably 1600 ° C. or higher, and the upper limit temperature is 1700 ° C.

The remelted material remelted in the ferrovanadium production step S4 is substantially free of nickel and vanadium, which is composed of ferrovanadium produced by the reduction reaction, Al ₂ O ₃ produced by the reduction reaction, and other substances. Includes slag. When both ferrovanadium and slag are melted, they can be divided into two layers depending on the specific gravity difference. That is, ferrovanadium having a high specific gravity can be divided into a lower layer, and slag having a low specific gravity can be divided into an upper layer.

The next ferrovanadium separation step S5 is a step of separating the remelted material from which ferrovanadium has been produced into ferrovanadium and slag. As described above, when the remelted material is in a molten state, it is divided into a lower ferrovanadium and an upper slag, so after transferring the remelted material from the heating furnace to the ladle, scrape the upper slag. Ferrovanadium and slag can be cast in separate molds. By doing in this way, a ferrovanadium lump and a slag lump can be obtained. In addition, when using a ladle having an outlet at the bottom, ferrovanadium lump and slag lump can be cast by putting ferrovanadium into the mold from the outlet and putting the remaining slag into another mold. it can. Note that the slag generated in the ferrovanadium separation step S5, like the V ₂ O ₅ containing slag described above, can be recovered metal component by means such as magnetic separation and flotation. Moreover, you may discard.

  The method for producing ferronickel and ferrovanadium according to the present invention is as described above, but in carrying out the present invention, in the range that does not adversely affect each of the above steps, before or after each of the above steps, For example, other steps such as a raw material crushing step for crushing each raw material, an unnecessary material removing step for removing unnecessary materials such as dust, and a containing step for containing the obtained ferronickel and ferrovanadium may be included.

  According to the production method described above, from petroleum combustion ash, for example, the Ni content is 41.4 to 42.3 mass%, the V content is 0.2 to 1.0 mass%, and the S content is Ferronickel having 0.08 to 0.28 mass%, C content of 0.18 to 6.14 mass%, the balance being Fe and inevitable impurities, and V content of 49.6 to 50.6 Mass%, Ni content is 0.2 to 0.4 mass%, S content is 0.1 to 0.3 mass%, C content is 0.2 to 0.5 mass%, and the balance is Fe And ferrovanadium, which is an inevitable impurity, can be produced.

  Next, the method for producing ferronickel and ferrovanadium according to the present invention will be specifically described by comparing an example satisfying the requirements of the present invention with a comparative example not satisfying the requirements of the present invention.

[First embodiment]
In order to grasp the reduction state of the mixed raw material of the present invention, the following reduction experiment was performed using a small-scale laboratory heating furnace.

  The blended raw materials include petroleum-based combustion ash, ash recovered from boilers using oil coke, and the residue after EP ash granulation in which carbon content is separated by wet granulation, coke powder (fixed carbon as a carbonaceous reducing agent) Calcium carbonate (limestone) was mixed in order to adjust the composition of slag by-produced as a slag forming agent. In addition, Table 2 shows the components after EP ash granulation used, coke powder, and calcium carbonate. Table 3 shows the blending ratios of the residue after EP ash granulation, coke powder, and calcium carbonate.

  Coke powder is a ratio of carbon content in the mixture (residue after EP ash granulation and carbon content in coke powder) to oxygen content in nickel oxide and iron oxide in petroleum combustion ash (C / O ) In a molar ratio of 1 or more, and the carbon remaining in the produced ferronickel was calculated so that the target C concentration in Table 3 was calculated. Thereby, coke powder is mix | blended so that it may become 1 or more by molar ratio with respect to the total amount of nickel in the ferronickel to produce | generate.

  In Table 3, (target Ni concentration) is the amount of nickel in the residue after EP ash granulation × the mixing ratio of the residue after EP ash granulation / (the amount of iron in the residue after EP ash granulation × EP ash granulation) The mixing ratio of the post-residue + the nickel amount in the post-EP ash granulation residue x the mixing ratio of the post-EP ash granulation residue). (Target V concentration) is the amount of V in the residue after EP ash granulation × the blending ratio of the residue after EP ash granulation / (the iron amount of the residue after EP ash granulation + the blending ratio of the residue after EP ash granulation + EP ash granulation) V amount in post-granule residue x blending ratio of residue after EP ash granulation). (Target C concentration) is: C concentration in coke powder x blending amount of coke powder + C concentration in residue after EP ash granulation x blending amount of residue after EP ash granulation-(Ni in residue after EP ash granulation) Concentration × 0.225 + Ni concentration in residue after EP ash granulation × 0.161) × Amount of residue after EP granulation / ((Ni concentration in residue after EP ash granulation + Fe in residue after EP ash granulation) Concentration) × EP ash granulation residue blending amount + C concentration in coke powder × Coke powder blending amount + EP ash granulation residue C concentration × EP ash granulation residue blending amount− (EP ash granulation Ni concentration in post-residue × 0.225 + Ni concentration in post-EP ash granulation residue × 0.161) × blending amount of EP post-granulation residue).

For mixing, an appropriate amount of water was added and granulated with a small pan pelletizer with a diameter of 600 mm to produce pellets with a diameter of about 13 mm. After 1000 grams of the pellets dried at 105 ° C. for 24 hours are charged into a small induction furnace equipped with a carbonaceous crucible having an inner diameter of 130 mm and a depth of 150 mm, the holding time is maintained at a constant ambient temperature. The mixture was heated for 30 minutes, reduced and melted, and then cooled to separate the slag content containing V ₂ O ₅ and the ferronickel content. The obtained ferronickel was chemically analyzed to determine the contents of Ni, V, and C (Ni concentration, V concentration, and C concentration). The atmosphere is a nitrogen atmosphere and the heating temperature (maximum heating temperature) is set to four levels of 1300, 1350 ° C., 1450 ° C., and 1550 ° C., heating is started, and the temperature is maintained for 30 minutes after reaching the maximum heating temperature (firing). . The results obtained in this heating experiment are shown in Table 3. Table 4 shows the composition of the slag containing V ₂ O ₅ produced in this heating experiment.

  In Table 3, the recovery rate (%) of ferronickel is ferronickel amount × Ni concentration / charged Ni amount. Here, the amount of charged Ni is the Ni concentration in the residue after EP ash granulation × the blending ratio. T. in Table 4 Fe is the concentration of metallic iron contained in the oxide.

As the evaluation, the recovery rate of ferronickel was determined, and those having a recovery rate of 80% or more were judged good, those having a recovery rate of 50% or more and less than 80% were good, and those having a recovery rate of less than 50% were judged bad. Moreover, the molten state of the sample after baking was investigated. The melted state is ◯ (excellent) when the sample is in a molten state after firing, △ (good) when the molten state is present but the slag and the iron alloy are not easily separated, and is not melted X (defect).
In Tables 2 to 4, "-" means that the component was not contained or the mixture was not melted and the ferronickel and the V ₂ O ₅ -containing slag could not be separated and the component could not be measured. Show. Moreover, about what does not satisfy | fill the structure of this invention, it shows by underlining a numerical value.

From the results in Table 3 and Table 4, the implementation No. Examples 1 to 9 and 13 to 15 satisfy the requirements of the present invention. Implementation No. In Nos. 1 to 9, the recovery rate of ferronickel was excellent, and the molten state of the sample after firing was also excellent. Implementation No. No. 13 has a CaO / SiO ₂ value less than the lower limit of the preferred range. In Nos. 14 and 15, since the CaO / SiO ₂ value exceeds the upper limit of the preferred range, the melting point of the V ₂ O ₅ -containing slag is increased, and the mixture is in a molten state, but ferronickel is V ₂ O _5. It was not easily separated from the contained slag. Therefore, the recovery rate of ferronickel is No. Although it decreased compared with 1-9, it was favorable.

On the other hand, the implementation No. 10 to 12 are comparative examples that do not satisfy the requirements of the present invention. Implementation No. In Nos. 10 to 12, since the heating temperature was lower than the lower limit, the mixture did not melt and ferronickel did not separate from the V ₂ O ₅ -containing slag. For this reason, ferronickel could not be recovered, and the recovery rate of ferronickel was poor.

Next, the implementation No. After charging 5.0 kg of each V ₂ O ₅ -containing slag obtained in 1 to 9 into a vacuum induction furnace, charging the amount of iron scrap shown in Table 5 together, heating to 1650 ° C., Of aluminum was added to each in the amounts shown in Table 5.
The remelted material thus obtained was transferred to a ladle and scraped out slag, and then the ferrovanadium and slag produced were put into respective molds and cast to obtain a ferrovanadium lump and slag lump. Table 5 shows the amount of iron scrap input, the amount of aluminum input, and the results obtained in this heating experiment.

  Here, in Table 5, the recovery rate (%) of ferrovanadium is ferrovanadium amount × V concentration / charge V amount. Here, the amount of charging V is V concentration x blending ratio in the residue after EP ash granulation.

  As evaluation, the recovery rate of ferrovanadium was calculated | required, the recovery rate of 80% or more was excellent, the recovery rate of 50% or more and less than 80% was good, and the thing of less than 50% was made bad.

  From the results in Table 5, the implementation No. Examples 1 to 9 satisfy the requirements of the present invention. Implementation No. 1 to 9 were excellent in the recovery rate of ferrovanadium.

[Second Embodiment]
Next, the following experiment was conducted using the rotary hearth type heating reduction furnace shown in FIG.
The same raw materials as in the first example were used. The formulation is No. 3 was used.

For mixing, an appropriate amount of water was added and granulated with a small pan pelletizer to prepare pellets having a diameter of about 13 mm. 1000 kg of the pellets dried at 105 ° C. for 24 hours was used. In the rotary hearth heating and reducing furnace, before charging the pellets, powdery coal is laid on the hearth to a thickness of 2 mm, and then the pellets are charged. The maximum temperature in the furnace is 1450 ° C. After performing the heat treatment for 12 minutes, it was discharged outside the furnace and cooled, and the V ₂ O ₅ -containing slag and ferronickel were separated and recovered by a screen.

Then, 5.0 kg of a part of the V ₂ O ₅ -containing slag separated and recovered was charged into a vacuum induction furnace, and 0.86 kg of iron scrap was charged together and heated to 1650 ° C., then granular aluminum 0.63 kg was added. The remelted material thus obtained was transferred to a ladle and scraped out slag, and then the ferrovanadium and slag produced were put into respective molds and cast to obtain a ferrovanadium lump and slag lump.
The recovery rates of the obtained ferronickel and ferrovanadium were determined in the same manner as shown in the first example. As a result, the recovery rate of ferronickel was 98%, and the recovery rate of ferrovanadium was 95%. .

On the other hand, 5.0 kg of a part of the separated and recovered V ₂ O ₅ -containing slag was charged into a vacuum induction furnace, and 0.86 kg of iron scrap was charged together and heated at 1450 ° C. It did not melt and ferrovanadium could not be recovered.
In addition, 5.0 kg of a portion of the slag containing V ₂ O ₅ that was separated and recovered was charged into a vacuum induction furnace, and 0.86 kg of iron scrap was charged together, and heated at 1500 ° C to melt the iron scrap. Then, when 0.63 kg of granular aluminum was added, a ferrovanadium lump could be obtained. As a result of obtaining the recovery rate of the obtained ferrovanadium in the same manner as shown in the first example, the recovery rate of ferrovanadium was 93%.
Incidentally, when recovering ferrovanadium from V ₂ O ₅ containing slag separated and recovered, for those exceeding 1650 ° C., was disadvantageous in terms of cost power usage becomes too increased.

  As mentioned above, although the best embodiment and the Example were shown and demonstrated in detail about the manufacturing method of the ferronickel and ferrovanadium which concern on this invention, the meaning of this invention is not limited to an above-described content. Needless to say, the contents of the present invention can be widely modified and changed based on the above description.

S1 mixing process S2 ferronickel production process S3 ferronickel separation process S4 ferrovanadium production process S5 ferrovanadium separation process 1 raw material input hopper 2 rotary hearth 3 combustion burner 4 metal lump 5 discharge device 6 discharge hopper 7 exhaust gas duct

Claims (10)

A method for producing ferronickel and ferrovanadium for producing ferronickel and ferrovanadium from petroleum combustion ash,
A mixing step of mixing a petroleum combustion ash containing nickel oxide, vanadium oxide and iron oxide, a carbonaceous reducing agent, and a slag forming agent to obtain a mixture;
A ferronickel production step in which the mixture mixed in the mixing step is heated and melted at 1350 to 1550 ° C. to form a melt, and the ferronickel produced in the melt is agglomerated;
A ferronickel separation step of separating the ferronickel and the vanadium oxide-containing slag after cooling the melt in which the ferronickel is agglomerated;
Ferrovanadium production in which the separated vanadium oxide-containing slag and the iron source are mixed and heated and melted at 1500 ° C. or higher and then a metal reducing agent is added to form a remelted product, and ferrovanadium is generated in the remelted product. Process,
A ferrovanadium separation step of separating the ferrovanadium-generated remelted material into the ferrovanadium and slag. A method for producing ferronickel and ferrovanadium, comprising: By using at least one of a CaO supply material and a SiO ₂ supply material as the slag forming agent, the ratio of CaO to SiO ₂ (CaO / SiO ₂ ) in the mixture is 0.2 to 1.65 by mass ratio. The method for producing ferronickel and ferrovanadium according to claim 1, wherein:   A ratio (C / O) between the amount of carbon in the mixture and the amount of oxygen contained in the iron oxide and nickel oxide is 1 or more in molar ratio, and carbon contained in the carbonaceous reducing agent is generated. The method for producing ferronickel and ferrovanadium according to claim 1 or 2, wherein the carbonaceous reducing agent is blended so as to remain in an amount of 6% by mass or less in the ferronickel.   The method for producing ferronickel and ferrovanadium according to claim 2, wherein at least one of calcium carbonate, quicklime and slaked lime is used as the CaO supply substance.   The ferronickel and ferrovanadium according to any one of claims 1 to 4, wherein a molded body of a carbonaceous material is used as a holding container for melting the mixture in the ferronickel production step. Manufacturing method.   The method for producing ferronickel and ferrovanadium according to any one of claims 1 to 5, wherein a rotary hearth furnace is used to melt the mixture in the ferronickel production step.   The ferronickel and the ferronickel according to claim 6, wherein, in the ferronickel generation step, before charging the mixture onto the hearth of the rotary hearth furnace, carbonaceous powder is spread on the hearth. A method for producing ferrovanadium.   The method for producing ferronickel and ferrovanadium according to claim 7, wherein the carbonaceous powder is spread on the hearth with a thickness of 2 mm or more.   The method for producing ferronickel and ferrovanadium according to any one of claims 1 to 8, wherein the metal reducing agent is at least one of Al and an Fe-Si alloy.   In the case where Al is used as the metal reducing agent, the Al is added so that the mass ratio is 0.5 with respect to the amount of vanadium oxide contained in the vanadium oxide-containing slag. The manufacturing method of ferronickel and ferrovanadium of description.

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