JP2009263723A - Method for producing ferromolybdenum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for highly efficiently and inexpensively producing ferromolybdenum without using molybdenum ore or the like as a raw material, and to provide the ferromolybdenum produced by the production method. <P>SOLUTION: The method for producing the ferromolybdenum includes: a mixing step (S1) of mixing a waste lubricating oil containing molybdenum disulfide of a raw molybdenum material with an iron-oxide-containing material of a raw iron material, a carbonaceous reducing agent, a desulfurizing agent and a slag-forming agent; a melting step (S2) of heating and melting the mixture mixed in the mixing step (S1) to form a molten material, and precipitating the produced ferromolybdenum, in the molten material; and a separating step (S3) of separating the ferromolybdenum in a slag that is produced by cooling the molten material in which the ferromolybdenum is precipitated, from the slag. In the melting step (S2), the heating temperature is controlled to 1,400 to 1,600&deg;C. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a ferromolybdenum production method for producing ferromolybdenum with high efficiency and low cost, and to ferromolybdenum produced by this production method.

Conventionally, there are mainly a thermite method and an electric furnace method as a method for producing ferromolybdenum, and the thermite method is currently used as the main production method.
As a method for producing ferromolybdenum by the thermit method, first, molybdenite (molybdenite) is used as a raw material for production, and molybdenum concentrate (about 85% molybdenum disulfide) is obtained by flotation. Bake to molybdenum oxide. And, this molybdenum oxide, iron source, reducing agent (ferrosilicon powder and aluminum particles) and solvent (iron ore, mill scale, etc.) are mixed to form a mixture, and a technology for producing ferromolybdenum using a thermite reactor. It has been proposed (see Non-Patent Document 1, for example).

Although the electric furnace method is not widely used at present, either an oxide ore or sulfide ore can be used as a molybdenum raw material. In the electric furnace method, a molybdenum raw material, an iron source, a reducing agent and a solvent are mixed to form a mixture, and ferromolybdenum is produced using the electric furnace. Here, when reducing, a reducing agent such as ferrosilicon or aluminum is used, and in order to fix the contained sulfur to the slag, the ratio of CaO to SiO ₂ (CaO / SiO ₂ ) is 3.0 by mass. The technique made above is proposed (see, for example, Patent Document 1). In addition, in a transition arc type plasma reactor using sulfide ore (shale lead ore) as a raw material, the raw material is supplied to the inner wall of the sleeve by a carrier gas, melted by an arc, and dropped into a crucible, whereby ferromolybdenum is added. A method of efficiently producing high purity has been proposed (see, for example, Patent Document 2).

  As another method for producing ferromolybdenum, a mixture of molybdenum metal and iron oxide is obtained by reducing the mixture of molybdenum oxide and iron oxide by two-stage reduction at 500 to 650 ° C. and 800 to 900 ° C. using a gaseous reducing agent. A method of obtaining has been proposed. A feature of this method is that molybdenum or iron does not melt during processing, and it utilizes dissociated ammonia, carbon monoxide, hydrogen, reformed hydrocarbons and mixtures thereof as gaseous reducing agents (eg, And Patent Document 3).

  As another production method, first, a binder is mixed with a mixture of about 10 to 90% by mass of metallized iron, about 7 to 65% by mass of molybdenum oxide, and about 5 to 26% by mass of solid carbonaceous material. And compacting to form briquettes, and charging the briquettes together with slag formation and additional carbonaceous materials into a shaft furnace such as a cupola. Then, a method has been proposed in which a carbonaceous material is burned to heat molybdenum oxide, reduce it to a metallic state, and dissolve iron and molybdenum to form molten ferromolybdenum in the furnace (for example, a patent). Reference 4).

Furthermore, as a method for producing iron alloy from waste containing molybdenum as a raw material, a method for recovering useful metals such as V, Mo, Ni from various wastes such as used petroleum desulfurization catalysts has been proposed. That is, heavy oil adhering to a used petroleum desulfurization catalyst using light oil such as kerosene is washed, and then centrifuged into a washed catalyst and an oil component. The washed catalyst is a mixture of other used catalyst (sulfuric acid production catalyst, maleic anhydride production catalyst, phthalic acid production catalyst) and heavy oil or combustion ash generated from a petcoke-fired boiler and molded into briquettes, etc. as necessary. To do. Then, the mixture or molded product is charged into a furnace bottom steel-type electric furnace, energized and melted, and Ni and Mo in the spent catalyst or combustion ash are charged with carbon in the combustion ash and separately charged. Is preferentially reduced by an iron source such as scrap, and becomes Ni—Mo alloy iron (see, for example, Patent Document 5).
Published by Japan Iron and Steel Institute, edited by Japan Iron and Steel Institute, Steel Handbook, Third Edition, Volume 2, Chapter 7, Section 3, Section 5 Japanese Examined Patent Publication No. 37-17112 JP 58-27937 A Japanese Patent Laid-Open No. 50-16607 JP-A-61-231134 JP 2004-35995 A

However, the above-described method for producing ferromolybdenum has the following problems.
In the thermite method described in Non-Patent Document 1, an oxidation roasting step of molybdenum concentrate is required, and a large amount of sulfurous acid gas is generated as a by-product. There was a problem that it was inferior in economic efficiency due to the cost of subsequent cooling treatment and crushing treatment of ferromolybdenum. Furthermore, rotary kilns have a large amount of dust generation, dam ring is likely to occur in the kiln, and the residence time of raw materials varies, so an excessive length of processing conveyance path is required, and the installation area of equipment is large. There were also problems such as an increase in the fuel consumption due to an increase in the surface area of the kiln and a large amount of heat dissipation.

The manufacturing methods of ferromolybdenum etc. described in Patent Documents 1 to 4 use molybdenum ore and the like. Here, due to the recent surge in molybdenum ore, a method for producing ferromolybdenum not using molybdenum ore as a raw material is required. In the production methods described in Patent Documents 1 to 4 using molybdenum ore or the like, the economical efficiency is inferior, There was a problem that the request could not be satisfied.
Furthermore, since the production method described in Patent Document 3 uses dissociated ammonia, carbon monoxide, hydrogen, reformed hydrocarbons and mixtures thereof as the gaseous reducing agent, it is necessary to prepare these gases separately. there were.

  The production method described in Patent Document 5 is to produce ferromolybdenum from various wastes such as used petroleum desulfurization catalyst, but the production method described in Patent Document 5 is mainly intended to recover vanadium, Since molybdenum is obtained in the form of Ni—Mo alloy iron, there is a problem that it is insufficient as a method for producing ferromolybdenum.

  The present invention has been made in view of the above-mentioned problems, and its object is to produce ferromolybdenum by using ferromolybdenum at high efficiency and at low cost without using molybdenum ore or the like as a raw material. To provide ferromolybdenum.

  As a result of extensive research on the method for efficiently and economically producing ferromolybdenum, the present inventors have used ferromolybdenum using a used lubricant (waste lubricant) containing molybdenum disulfide as a molybdenum raw material. And the ferromolybdenum produced by this production method has been invented.

  That is, the method for producing ferromolybdenum according to claim 1 includes a mixing step of mixing a waste lubricant containing molybdenum disulfide as a molybdenum raw material, an iron oxide-containing substance, a carbonaceous reducing agent, a desulfurizing agent, and a slag forming agent as an iron raw material. The mixture mixed in the mixing step is heated and dissolved to form a dissolved product, and the dissolution step of precipitating the produced ferromolybdenum in the dissolved product, and cooling the dissolved product of precipitating the ferromolybdenum. A separation step of separating the generated slag and ferromolybdenum in the slag, wherein the heating temperature is controlled to 1400 to 1600 ° C. in the melting step. Here, the iron oxide-containing substance refers to iron oxide itself, other iron oxides, and other Fe oxides.

According to such a manufacturing method, molybdenum disulfide (MoS ₂ ), an iron oxide-containing substance, a carbonaceous reducing agent, a desulfurizing agent, and a slag forming agent are mixed in the mixing step. In the melting step, MoS ₂ reacts with oxygen (O) contained in the iron oxide to be converted to molybdenum oxide, and then reduced by carbon (C) to become metallic molybdenum. Precipitate. Further, sulfur (S) contained in MoS ₂ is also partially immobilized with a compound such as FeOS. In the separation step, the generated slag and the ferromolybdenum in the slag are separated to produce ferromolybdenum.
In addition, heating the mixture to the melting point (1400 ° C.) or higher dissolves the mixture, and controlling the heating temperature to 1600 ° C. or lower increases the concentration of C contained in ferromolybdenum and increases the specified electric energy. Is prevented.

The method for producing ferromolybdenum according to claim 2 uses a CaO-containing substance as the desulfurizing agent, uses a SiO ₂ -containing substance as the slag forming agent, and a ratio of CaO and SiO ₂ in the mixture (CaO / SiO ₂ ). Is 1.0 to 1.2 in terms of mass ratio, and the ratio of the amount of carbon in the mixture to the amount of oxygen contained in the iron oxide (C / O) is 1.00 to 1.21 in terms of molar ratio. Features. In addition, the CaO containing substance here means CaO itself and the oxide of other Ca other than the substance containing CaO. Further, the SiO ₂ containing material, other materials containing SiO _2, SiO ₂ itself and refers to the oxides of other Si.

According to such a manufacturing method, by supplying (compounding) CaO as a desulfurizing agent, S contained in MoS ₂ in the mixture is fixed as CaS, and the generated FeOS is reduced to iron. At the same time, S is fixed to the slag generated by reacting with CaO to be blended. Further, the SiO ₂ was supplied (blended) as slag forming agent, the ratio in the mixture (CaO / SiO ₂₎ by 1.0 to 1.2 by mass ratio, the mixture is likely to dissolve.
Furthermore, the carbon concentration in the ferromolybdenum is suppressed by setting the ratio (C / O) of the amount of carbon in the mixture and the amount of oxygen contained in the iron oxide to 1.00 to 1.21 in molar ratio. The amount of carbon necessary to reduce iron oxide is supplied.

The method for producing ferromolybdenum according to claim 3 is characterized in that calcium carbonate and / or calcined lime is used as the CaO-containing substance.
According to such a manufacturing method, CaO can be efficiently supplied by using calcium carbonate and / or calcined lime as the CaO-containing substance, and economic efficiency is improved.

The method for producing ferromolybdenum according to claim 4 is characterized in that the desulfurizing agent contains a Li ₂ O-containing substance. Note that the Li ₂ O-containing material here, other materials containing Li ₂ O, Li ₂ O itself and refers to the oxides of other Li.
According to such a production method, by supplying (blending) Li ₂ O as a desulfurizing agent, the melting point of the slag to be generated is lowered, and the sulfur distribution to the slag is improved. Thereby, it becomes easy to fix S to the generated slag.

The method for producing ferromolybdenum according to claim 5 is characterized in that lithium oxide and / or lithium carbonate is used as the Li ₂ O-containing substance.
According to this production method, by using the lithium oxide and / or lithium carbonate as a Li 2 _O-containing substances, can be efficiently supplied to Li 2 _O, also, economic efficiency is improved.

The method for producing ferromolybdenum according to claim 6 is characterized in that, in the melting step, a carbonaceous material is used for a holding container for dissolving the mixture.
According to such a manufacturing method, it becomes easy to take out the dissolved mixture from the holding container.

The ferromolybdenum according to claim 7 is manufactured by the ferromolybdenum manufacturing method described above.
Such ferromolybdenum has a high Mo content and a low S content.

According to the method for producing ferromolybdenum according to claim 1 of the present invention, ferromolybdenum having a high Mo concentration can be stably produced with high efficiency and low cost.
According to the method for producing ferromolybdenum according to claim 2, the S concentration and the C concentration in ferromolybdenum can be suppressed, and the mixture is easily dissolved.
According to the method for producing ferromolybdenum according to claim 3, CaO can be supplied efficiently and economically.

According to the method for producing ferromolybdenum according to claim 4, the S concentration in ferromolybdenum can be further suppressed.
According to the method for producing ferromolybdenum according to claim 5, Li ₂ O can be supplied efficiently and economically.
According to the ferromolybdenum production method of the sixth aspect, the dissolved mixture can be easily taken out from the holding container.
Since the ferromolybdenum according to claim 7 is manufactured by the above manufacturing method, it has a high Mo concentration and a low S concentration, and can be obtained efficiently and economically.

  Next, a ferromolybdenum production method according to the present invention and the ferromolybdenum produced by this production method will be described in detail with reference to the drawings. In the drawings to be referred to, FIG. 1A is a diagram showing a flow of a ferromolybdenum production method, and FIG. 1B is a diagram showing a substance flow in each step.

≪Method for producing ferromolybdenum≫
As shown in FIG. 1A, the method for producing ferromolybdenum includes a mixing step (S1), a dissolving step (S2), and a separation step (S3).
Hereinafter, each step will be described.

<Mixing process>
As shown in FIG. 1B, the mixing step (S1) includes a waste lubricant containing molybdenum disulfide as a molybdenum raw material, an iron oxide-containing substance, a carbonaceous reducing agent, a desulfurizing agent, and a slag forming agent (hereinafter referred to as “iron raw material”). , Also referred to as “raw material” as appropriate).

[Waste lubricant containing molybdenum disulfide]
Molybdenum disulfide serves as a molybdenum raw material contained in the ferromolybdenum produced, and a waste lubricant containing molybdenum disulfide is used as the molybdenum disulfide raw material (molybdenum raw material). Here, the waste lubricant is a used lubricant.

[Iron oxide-containing substances]
The iron oxide in the iron oxide-containing substance (iron oxide supply substance) oxidizes molybdenum disulfide with oxygen contained in the iron oxide. As the iron oxide-containing substance, iron oxide is supplied into the mixture ( It is not particularly limited as long as it can be blended), and iron ore (iron ore powder), scale (mill scale), and the like can be used.
The amount of iron oxide-containing material is determined based on the iron oxide supplied (blended) with respect to the ratio of molybdenum to iron in the waste lubricant, calculated from the desired molybdenum concentration (target Mo concentration). Here, when iron ore is used, the target Mo concentration = the amount of molybdenum in the waste lubricant × the amount of waste lubricant / (the amount of molybdenum in the lubricant × the amount of waste lubricant + the amount included in the iron ore Amount of iron to be added x amount of iron ore).

[Carbonaceous reducing agent]
The carbonaceous reducing agent is for reducing iron oxide, and the carbonaceous reducing agent may be any material that contains fixed carbon, such as coal, coke, charcoal, waste toner, and biomass carbide. In addition, these may be mixed as appropriate.
The compounding ratio of the carbonaceous reducing agent in the mixture is calculated from the desired molybdenum concentration (target Mo concentration). The iron oxide compounded with respect to the ratio of molybdenum to iron in the waste lubricant is used in the heating furnace. The amount is determined so as to be more than the amount of carbon necessary for reduction.

The amount of carbonaceous reducing agent (fixed carbonaceous) to be blended may be blended in consideration of the mass of fixed carbon contained in the substance (coal, etc.), but relative to the amount of oxygen contained in the blended iron oxide It is preferable that the molar ratio is equal to or more than that. However, even if carbon is added more than reducing iron oxide, it is only necessary to transfer carbon to the resulting ferromolybdenum, so there is no need to add more.
That is, the molar ratio (C / O) between the amount of carbon in the mixture and the amount of oxygen contained in the iron oxide is preferably 1.00 to 1.21.
When the molar ratio (C / O) is less than 1.00, the iron oxide is difficult to be reduced. On the other hand, when it exceeds 1.21, the carbon concentration of the obtained ferromolybdenum tends to be high.

[Desulfurizing agent]
The desulfurizing agent is blended together with the slag forming agent in order to immobilize S in the slag, and it is preferable to use a CaO-containing substance (CaO supply substance).
The CaO-containing substance is not particularly limited as long as it is a substance that can supply (formulate) CaO in the mixture, but calcium carbonate (lime) and / or calcined lime is used from the viewpoint of efficiency and economy. Preferably, slaked lime or the like may be used. Moreover, if it contains impurities other than SiO ₂ , the blending amount is determined in consideration of the CaO content. In addition, you may use these, mixing.

In addition, when determining the blending amount, the amount contained as ash in the carbonaceous reducing agent (carbon-containing substance) and CaO contained in the waste lubricant for viscosity adjustment when used as a waste lubricant are also taken into consideration. To determine the amount.
In addition, CaO or the like contained in the waste lubricant may be used as a desulfurizing agent component, and when there is little CaO or the like contained in the waste lubricant, CaO or the like may be further blended.
That is, a waste lubricant can be used as a desulfurization agent, and the waste lubricant in this case is a mixture of a waste lubricant containing molybdenum disulfide and a desulfurization agent.
In addition to CaO-containing materials, MgO-containing materials can be used as desulfurizing agents. However, since MgO is inferior in reaction capacity to CaO, it is usually mixed by replacing part of the CaO-containing material with MgO-containing materials. To do.

Furthermore, the desulfurization agent preferably contains a Li ₂ O-containing material (Li ₂ O feed materials). Thereby, by supplying (blending) Li ₂ O, the melting point of the slag to be generated is lowered, and the sulfur distribution to the slag is improved. Therefore, S is easily fixed to the generated slag, and the S concentration in the obtained ferromolybdenum can be further reduced.

The Li ₂ O-containing material is not particularly limited as long as it is a material capable of supplying (compounding) Li ₂ O into the mixture. From the viewpoint of efficiency and economy, for example, lithium oxide (Li ₂ O ) And / or lithium carbonate (Li ₂ CO ₃ ) may be used.

When blending the Li ₂ O-containing material, Li ₂ O content in the slag to be produced is preferably at least 0.05 wt%, more preferably, 0.1 mass% or more, more preferably, It is 0.3 mass% or more. In addition, it is preferable that an upper limit is 12 mass%. As described above, by actively containing Li ₂ O, sulfur distribution to the slag is improved, but when the content of Li ₂ O in the slag is too large, the evaporation of the Li ₂ O component becomes intense, This is because the evaporated Li ₂ O reacts with the refractory in the heating furnace to accelerate damage to the heating furnace.

In this manner, by appropriately adjusting the content of Li 2 _O in the slag to be generated, it is possible to manufacture the ferro-molybdenum low sulfur content efficiently.
In addition to Li oxides such as Li ₂ O-containing substances, oxides of other Group 1 elements also have an effect of improving sulfur distribution to slag.

[Slag forming agent]
The slag forming agent is blended with a desulfurizing agent in order to immobilize S in the slag, and it is preferable to use a SiO ₂ -containing material (SiO ₂ supply material). The above-described waste lubricant, iron oxide-containing material, carbonaceous reducing agent, and the like contain SiO ₂ as an impurity, but since the amount of SiO ₂ contained in these is very small, as described below, CaO / In addition to SiO ₂ contained as an impurity, it is preferable to further blend a SiO ₂ -containing substance so that SiO ₂ has a mass ratio of 1.0 to 1.2.

The SiO ₂ -containing material is not particularly limited as long as it is a material that can supply (formulate) SiO _{2 in the} mixture, and silica stone, silica sand, or the like can be used. In addition, in these uses, it is necessary to grind | pulverize to about 100 micrometers or less.
Wollastite can also be used as a mineral containing CaO and SiO ₂ at the same time.
SiO ₂ is blended to react with CaO to melt the mixture as slag at the processing temperature in the dissolution step (S2).

Here, the waste lubricant in the iron oxide-containing material and carbonaceous reducing agent, when adding CaO-containing material and a SiO ₂ containing material, the weight ratio of CaO and SiO ₂ (CaO / SiO ₂₎ is 1.0 It is preferable to determine the total blending ratio by blending so as to be 1.2.
If the mass ratio of CaO to SiO ₂ (CaO / SiO ₂ ) is less than 1.0, S is difficult to fix in the slag, while if it exceeds 1.2, the mixture is difficult to dissolve (melt).

When the mixture contains only a small amount of CaO and SiO ₂ , one of CaO or SiO ₂ or both CaO and SiO ₂ is blended, and the mass of slag is relative to the mass of the amount of ferromolybdenum obtained. It is preferable that the slag is by-produced so as to be 0.1 times or more and the S component contained in the raw material is fixed.
The amount of ferromolybdenum obtained is the total amount of iron contained in the blended iron ore and the like and the amount of molybdenum in the blended waste lubricant.

Here, as shown in FIG. 1B, a mixer is used to mix the waste lubricant, the iron oxide-containing substance, the carbonaceous reducing agent, the desulfurizing agent, and the slag forming agent. Moreover, it is preferable to agglomerate the mixed mixture 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 (agglomerate) in the heating furnace becomes easy to move. It is because it can prevent that becomes dust. As the granulator, in addition to a compression molding machine such as a briquette press and a rolling granulator such as a disk type pelletizer, an extrusion molding machine may be used.
In addition, when a raw material contains much water | moisture content, it is preferable to dry beforehand. The degree of drying may be determined in consideration of mixing means in the mixing step (mixer in the present embodiment). Moreover, when the water | moisture content of the mixture (aggregate) after granulation is high, you may dry before charging to a heating furnace.

<Dissolution process>
The dissolution step (S2) is a step in which the mixture mixed in the mixing step (S1) is heated and dissolved to form a dissolved product, and the produced ferromolybdenum is precipitated in the dissolved product, and a step of causing a reduction reaction. But there is.
As shown in FIG.1 (b), the mixture mixed with the mixer or the agglomerate granulated with the granulator is charged into a heating furnace and heated and melted. As a heating furnace, a furnace equipped with a crucible such as a resistance heating furnace or an induction heating furnace can be used. As other heating furnaces, rotary hearth furnaces, linear furnaces, multi-stage furnaces, etc. can be used. In these moving hearth furnaces, the mixture (agglomerates) to be heated is left on the hearth. Therefore, the generation of dust and the like is small, and all the furnaces are compact, and the equipment cost and the installation area can be saved as compared with the rotary kiln.

Next, an example of the reduction reaction in the dissolution step (S2) will be described.
The outline of the reduction reaction of the present invention is shown by the following formula.
FeO _X + MoS ₂ + CaO + C → Fe + Mo + CaS + CO
(Low temperature)
MoS ₂ + C + FeO _X → MoO ₃ + FeOS + CO ₂
MoS ₂ + C + CaO → MoO ₃ + CaS + CO ₂
(High temperature)
MoO ₃ + C + FeO _X → Mo + Fe + CO
FeOS + C → Fe + CO + S (in slag)
Here, MoS ₂ is molybdenum disulfide as a molybdenum raw material contained in the waste lubricant, FeO _X is iron oxide contained in an iron oxide-containing material as an iron raw material, C is a carbonaceous reducing agent, and CaO is a desulfurizing agent. is there.

In this reaction process, MoS ₂ contained in the waste lubricant reacts with oxygen contained in the iron oxide to be converted into molybdenum oxide and then reduced to carbon to form metallic molybdenum, and the yield is lowered by one-stage heat treatment. Ferromolybdenum is produced without any problems. A part of S contained in MoS ₂ in the lubricant is also fixed with a compound such as FeOS, and at the same time CaO is fixed as a desulfurizing agent, so that it is fixed as CaS. Further, FeOS is reduced to iron, and S is fixed to the slag produced by reacting with CaO to be blended.

Here, in dissolving (melting) the mixture (agglomerate), it is preferable to use a carbonaceous material (carbonaceous molded body) as a holding container. By using a carbonaceous material as the holding container, it becomes easy to take out a dissolved material in which the mixture is dissolved from the holding container after melting due to the lubricity of carbon.
Furthermore, in order to dissolve the mixture (agglomerated material), it is necessary to heat to the melting point or higher. For this reason, the heating temperature (maximum heating temperature) needs to be 1400 ° C. or higher. In addition, when heated in a carbonaceous material holding container, from the viewpoint of preventing the increase in C power contained in the ferromolybdenum by reacting with the produced ferromolybdenum when the temperature is raised, and the increase in the amount of specified electric power. Heat at below ℃.

  The ferromolybdenum produced in the present invention is produced as ferromolybdenum particles in the molten slag, and the ferromolybdenum particles are solid within the range of the heating temperature. For this reason, while being held at the heating temperature, the ferromolybdenum particles precipitate in the molten slag, and the slag and ferromolybdenum are physically separated. Since these ferromolybdenum particles partially entrain slag components during precipitation, ferromolybdenum contains a small amount of Ca and S as components.

<Separation process>
The separation step (S3) is a step of separating slag generated by cooling the melted ferromolybdenum and ferromolybdenum precipitated in the slag.
As shown in FIG.1 (b), the melt | dissolution agglomerate (reduction mixture) which is the melt | dissolved and reduce | restored within the heating furnace is cooled after completion | finish of a heating, and is discharged | emitted from a crucible or a hearth. This cooled reduced solidified product, which is a reduced mixture, is crushed by a crusher and sieved to ferromolybdenum (metal) and slag by a sieve. This separation by crushing and sieving can be performed using a screen in addition to being performed manually. The obtained slag can be used for aggregates for concrete. In addition, from the separated slag, the ferromolybdenum content can be further recovered by means such as magnetic separation or flotation as necessary.

≪Ferromolybdenum≫
The ferromolybdenum according to the present invention is obtained by a production method comprising the above-described steps.
According to the manufacturing method described above, for example, the Mo content is 25.6 mass% or more and 67.1 mass% or less, the S content is 1.62 mass% or more and 16.9 mass% or less, and the C content Is 0.56 mass% or more and 6.81 mass% or less, Ca content is 0.02 mass% or more and 5.42 mass% or less, and the remainder can obtain ferromolybdenum which uses Fe and inevitable impurities. it can.

Further, by adding a Li ₂ O-containing substance to the desulfurizing agent, the S content is reduced, for example, the Mo content is 35.1 mass% or more and 65.1 mass% or less, and the S content is 0. .48 mass% or more and 10.40 mass% or less, C content is 0.59 mass% or more and 6.78 mass% or less, and Ca content is 0.04 mass% or more and 5.12 mass% or less. There can be obtained ferromolybdenum with the balance being Fe and inevitable impurities.

  Next, the ferromolybdenum production method and ferromolybdenum according to the present invention will be specifically described by comparing an example that satisfies the requirements of the present invention with a comparative example that does not satisfy 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 compounding raw materials are used lubricants (waste lubricants) containing molybdenum disulfide, the iron oxide raw materials are hematite iron ores that are iron oxide-containing materials, and the carbonaceous reducing agent is coke powder (fixed carbon) In order to adjust the composition of by-product slag as a slag forming agent, silica sand was mixed. Table 1 shows the components of the used lubricant, iron oxide-containing substance, carbonaceous reducing agent, and slag forming agent. Incidentally, waste lubricants are those mainly composed of MoS _2. Lubricants include those containing MoS ₂ as a main component and containing oils, but depending on the application, some may contain calcium soap or the like to adjust the viscosity. In this example, CaO as a desulfurizing agent is used. Was used. Note that the lubricant containing CaO is equivalent to lime (calcium carbonate) or calcined lime as a desulfurization agent.

The blending was performed so that the ratio of iron contained in iron ore (target Mo concentration) was 40%, 60%, and 65% with respect to the amount of Mo in the waste lubricant. That is, the amount of molybdenum in the waste lubricant × the amount of waste lubricant / (the amount of molybdenum in the waste lubricant × the amount of waste lubricant + the amount of iron contained in the iron ore × the amount of iron ore) = That is 40%, 60%, 65%.
Next, the coke powder was blended so that the ratio (C / O) to oxygen contained in the iron oxide was 0.47 to 1.40 in molar ratio. Furthermore, for some, silica sand is mixed so that CaO / SiO ₂ is 0.8 to 1.2 by mass ratio with respect to CaO contained therein, and for some, silica sand is mixed. I didn't.

  Mixing was performed by adding an appropriate amount of water and granulating with a small disk type pelletizer to produce pellets having 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 dissolved, and then cooled to separate the slag and ferromolybdenum components. The obtained ferromolybdenum was chemically analyzed to determine the contents (concentrations) of Mo, S, C, and Ca. The atmosphere is a nitrogen atmosphere, and the heating temperature (maximum heating temperature) is set to four levels of 1350 ° C., 1400 ° C., 1500 ° C. and 1600 ° C., and 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 2.

In Table 2, C / O is the molar ratio of the fixed carbonaceous material and oxygen contained, CaO / SiO ₂ is the ratio of the CaO mass and SiO ₂ mass contained, and the ferromolybdenum recovery rate is the recovered ferromolybdenum amount × Mo concentration / charged Mo amount. The amount of charged Mo is the amount of Mo calculated from the Mo concentration contained in the waste lubricant x the blending ratio.

As the evaluation, the ferromolybdenum recovery rate was determined, and those having a ferromolybdenum recovery rate of 80% or more were determined to be excellent, those having 50% to less than 80% were good, and those having less than 50% were determined to be poor. For reference, the molten state of the sample after firing was examined. The melted state was evaluated as “◯” when the sample was in a molten state after firing, “Δ” when the sample was in a molten state but the slag and ferromolybdenum were not easily separated, and “X” when the sample was not melted.
In Tables 1 and 2, those that do not contain a component or that could not be measured are indicated by “−”. Moreover, about what does not satisfy | fill the structure of this invention, it shows by underlining a numerical value.

Implementation No. 1 to 25 are examples that satisfy the requirements of the present invention, and the ratio of carbonaceous material contained in the mixture to oxygen in the total iron oxide content contained in the blended iron ore and waste lubricant (C / O) ) In a molar ratio of 0.47 to 1.40. Implementation No. No. 1 was heated at 1500 ° C. with C / O = 1.04, and the ferromolybdenum recovery rate was excellent at 82%. In addition, the implementation No. Nos. 2 to 19 and 25 are CaO / SiO _{2 made} to be about 1.2 for the purpose of lowering the concentration of S contained in ferromolybdenum and heated at 1400 ° C, 1500 ° C or 1600 ° C. The recovery rate of ferromolybdenum was excellent at 80% or more. However, the implementation No. No. 25 had a high carbon concentration in ferromolybdenum because C / O exceeded 1.21 in terms of molar ratio.

  Implementation No. 20 to 24, C / O does not satisfy the range of 1.00 to 1.21 in terms of molar ratio, but the requirements of the present invention are satisfied, so the recovery rate of ferromolybdenum is in the range of 50% or more and less than 80%. It was good. In addition, since the amount of carbon necessary for the reaction is small, the reduction reaction is small, and it is difficult to fix S in the slag, so the S concentration contained in the obtained ferromolybdenum is as high as 5.6 to 16.9% by mass. It was.

  In addition, since C / O is less than 1.00 in molar ratio, the amount of carbon to be reduced is less than the amount of oxygen to be reduced, and ferromolybdenum cannot be completely formed, and the reaction is completed halfway. did. Therefore, the slag content and the ferromolybdenum content do not separate up and down. 21 to 24 had a melting state of Δ. Implementation No. No. 20 is an implementation no. Since the value of C / O was slightly higher than 21 to 24, the melted state was good.

Implementation No. Nos. 26 to 34 are comparative examples that do not satisfy the requirements of the present invention. The ratio of the carbonaceous material contained in the mixture to the oxygen content in the iron oxide contained in the blended iron ore and waste lubricant (C / O) ) In a molar ratio of 0.47 to 1.30. Among these comparative examples, the implementation No. Nos. 26 to 31 were heated at 1350 ° C., but the slag content to be generated as a by-product was not melted and ferromolybdenum could not be separated even if the reaction occurred, so ferromolybdenum could not be recovered, and the recovery rate of ferromolybdenum was It was bad. Implementation No. Nos. 32 to 34 were obtained by adding silica sand as a slag forming agent. Therefore, the basicity (CaO / SiO ₂ ) became extremely large, and the melting point of slag became high. Therefore, even when heated at 1600 ° C., the slag content did not melt. Therefore, since ferromolybdenum cannot be separated into slag, ferromolybdenum cannot be recovered, and the recovery rate of ferromolybdenum is poor. In addition, since these could not isolate | separate ferro molybdenum, a component was not measurable.

[Second Embodiment]
In the second example, the S concentration in ferromolybdenum when a Li ₂ O-containing material was blended was examined. As the Li ₂ O-containing material, because it is preferable to use Li ₂ O or _Li 2 CO _3, as the Li ₂ O-containing substance, both are equivalent, in the present embodiment, as a representative, Li ₂ CO ₃ was used.

A Li ₂ O-containing material was further blended with the same blending raw material as in the first example so that the Li ₂ O content in the slag had a concentration shown in Table 3. Other experimental methods and evaluation methods are the same as in the first example.
The results obtained in this heating experiment are shown in Table 3.

As shown in Table 3, the implementation No. 35-59 is an embodiment which satisfies the requirements of the present invention, except that blended Li ₂ O-containing material, implementation of the first embodiment, respectively No. 1 to 25 (see Table 2). As shown in Tables 2 and 3, the implementation No. Nos. 35 to 59 are the same conditions as in Example No. 1 of the first example except that a Li ₂ O-containing material was blended. Compared with 1 to 25, the S concentration in ferromolybdenum was low.

  The ferromolybdenum production method and ferromolybdenum according to the present invention have been described in detail with reference to the best mode and examples, but the gist of the present invention is not limited to the above-described contents. Needless to say, the contents of the present invention can be widely modified and changed based on the above description.

(A) is a figure which shows the flow of the manufacturing method of ferro molybdenum, (b) is a figure which shows the flow of the substance in each process.

Explanation of symbols

S1 mixing process S2 dissolution process S3 separation process

Claims (7)

A mixing step of mixing a waste lubricant containing molybdenum disulfide as a molybdenum raw material, an iron oxide-containing substance, a carbonaceous reducing agent, a desulfurizing agent, and a slag forming agent as an iron raw material;
The mixture mixed in the mixing step is heated, dissolved to form a dissolved product, and the dissolved step of precipitating the produced ferromolybdenum in the dissolved product,
A slag generated by cooling the melted ferromolybdenum and a separation step of separating the ferromolybdenum in the slag,
In the melting step, the heating temperature is controlled to 1400 to 1600 ° C. A CaO-containing substance is used as the desulfurizing agent, a SiO ₂ -containing substance is used as the slag forming agent, and the ratio of CaO to SiO ₂ (CaO / SiO ₂ ) in the mixture is 1.0 to 1.2 by mass ratio. And the ratio (C / O) of the amount of carbon in the said mixture and the amount of oxygen contained in iron oxide (C / O) is 1.00-1.21 in molar ratio, The ferromolybdenum of Claim 1 characterized by the above-mentioned. Production method.   The method for producing ferromolybdenum according to claim 2, wherein calcium carbonate and / or calcined lime is used as the CaO-containing substance. The desulfurizing agent manufacturing method of ferromolybdenum according to any one of claims 1 to 3, characterized in that it comprises a Li 2 _O-containing material. The method for producing ferromolybdenum according to claim 4, wherein lithium oxide and / or lithium carbonate is used as the Li ₂ O-containing substance.   The method for producing ferromolybdenum according to any one of claims 1 to 5, wherein a carbonaceous material is used in a holding container for dissolving the mixture in the dissolving step.   A ferromolybdenum produced by the method for producing ferromolybdenum according to any one of claims 1 to 6.

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