KR100953664B1 - Production Method of Fe-Mo Alloy. - Google Patents

Abstract

The present invention relates to a method for producing a ferro-molybdenum alloy, and more particularly, powder, agglomerate or a mixture of iron oxide and molybdenum oxide mixed with them are charged in an inconel crucible and heated and melted using hydrogen gas It relates to a method for producing a ferro-molybdenum alloy by producing a ferro-molybdenum alloy by reducing.

The method for producing a ferro-molybdenum alloy of the present invention,

A mixing step of mixing the powder, the lump or the mixed iron oxide and molybdenum oxide;

Dissolving step of first heating up to a certain temperature to dissolve the mixture into a liquid state;

A reduction step of reducing by injecting hydrogen gas into the dissolved mixture;

And a cooling step of cooling and solidifying the ferro-molybdenum alloy in the high-temperature molten liquid state to transform it into a solid state at room temperature.

Through the present invention, the process is shortened by dissolving a powder, agglomerate or a mixture of mixed iron oxide and molybdenum oxide and hydrogen reduction to produce a ferro-molybdenum alloy. Slag forming agent, complexing agent, etc.), the investment cost of the environmental pollution prevention facility can be reduced, and the labor cost can be reduced to reduce the manufacturing cost.

Steelmaking, ferro, molybdenum, dissolution reduction.

Description

Production method of ferro-molybdenum alloy {Production Method of Fe-Mo Alloy.}

The present invention relates to a method for producing a ferro-molybdenum alloy, and more particularly, powder, agglomerate or a mixture of iron oxide and molybdenum oxide mixed with them are charged in an inconel crucible and heated and melted using hydrogen gas It relates to a method for producing a ferro-molybdenum alloy by producing a ferro-molybdenum alloy by reducing.

In the steelmaking process, a small amount of special metal is added to the molten metal in order to improve the properties of the steel, and molybdenum is present in the small amount of the added metal.

Although molybdenum oxide may be added in order to add molybdenum, a ferro-molybdenum alloy may be added in some cases.

Molybdenum is mainly used in heat-resistant steel because it improves the hot creep properties of steel and prevents temper brittleness, and it is also added to cast iron to improve the heat resistance of cast iron.

Ferro-molybdenum alloys are generally prepared by a Thermit reaction.

The thermite reaction causes deoxygenation (reduction) of the metal oxide material using a low melting point metal having a strong oxidation power, and the metal oxide material is dissolved and reduced and alloyed by the heat of oxidation reaction of the low melting point strong oxidant metal. In general, aluminum, magnesium, etc. are used as the low melting point strong oxidizing metal.

In the thermite reaction for producing a ferro-molybdenum alloy, complexing is usually performed by mixing aluminum, iron, molybdenum oxide, and slag forming agent to cause a high temperature oxidation reaction (thermite reaction). Ferro-molybdenum alloys are prepared.

The disadvantage of manufacturing ferro-molybdenum alloy by thermite method is that aluminum, slag forming agent, and complexing agent are required for thermite reaction, so that materials other than the raw materials of iron and molybdenum are added in a large amount, and thermite In order to facilitate the reaction, a granulation process is added to make the mixed raw material a certain size.

Thermite reactions also explode in a short time (a few minutes), so an environmental pollution prevention facility is needed to deal with many environmental pollutants and dusts.

On the other hand, in order to manufacture ferro-molybdenum alloy due to the huge amount of slag generated after the thermite reaction and the waste cost of the waste foundry, the material cost, labor cost, waste disposal cost, and environmental pollution prevention facility cost are extra high. If necessary, the company loses its competitiveness due to high manufacturing costs.

However, most of all, the complexing and thermite reactions react explosively in a very short time, which is a dangerous process that can lead to safety accidents.

In addition, some expensive molybdenum is present in the slag to be discarded, there is also a problem that reduces the recovery rate of molybdenum.

On the other hand, the disadvantage of the ferro-molybdenum alloys produced by the thermite method is that the density of the ferro-molybdenum alloys (about 8.8 g / cm ³ ) is higher than that of molten steel (about 7.5 g / cm ³ ). When ferro-molybdenum alloys are introduced into steel, the high density of ferro-molybdenum alloys causes them to settle rapidly to the lower part of the molten metal, resulting in a slow dissolution rate of the ferro-molybdenum alloys into the molten metal. It has the disadvantage of having it.

On the other hand, in the thermite reaction, problems such as the incorporation of impurities such as the incorporation of the molten sand of the foundry sand by the heat of high temperature oxidation reaction and the incorporation of the foundry sand in the separation of the foundry sand and the ferro-molybdenum alloy after the thermite reaction occur.

In addition, differences in the composition (content) of the ferro-molybdenum alloy ingots have arisen, thereby causing a problem of reproducibility regarding the homogeneous composition of the ferro-molybdenum alloy.

Therefore, the present invention has been proposed in view of the problems of the prior art as described above, and an object of the present invention is to shorten the process during the production of ferro-molybdenum alloy, and to reduce the material to be input other than the raw materials of Fe and Mo. In addition, it is possible to reduce manufacturing costs by reducing investment costs of environmental pollution prevention facilities and labor costs.

Another object of the present invention is to exclude the explosive thermite reaction to block the safety accident factors, to prevent the incorporation of impurities, to prevent the reduction of molybdenum recovery rate, and to eliminate the generation of waste such as slag and waste casting sand.

Still another object of the present invention is to facilitate melt diffusion into a solution by securing excellent quality of homogeneous composition and lowering density of ingots.

It is still another object of the present invention to produce a lower density of ferro-molybdenum alloy so that the ferro-molybdenum alloy is more soluble in the solvent, thereby delaying the rate at which the ferro-molybdenum alloy is settled to the lower part of the solution. It is to shorten the steelmaking time by increasing the melting speed of the furnace.

In order to achieve the problem to be solved by the present invention,

Method for producing a ferro-molybdenum alloy according to an embodiment of the present invention,

A mixing step of mixing the powder, the lump or the mixed iron oxide and molybdenum oxide;

Dissolving step of first heating up to a certain temperature to dissolve the mixture into a liquid state;

A reduction step of reducing by injecting hydrogen gas into the dissolved mixture;

And a cooling step of cooling and solidifying the ferro-molybdenum alloy in the high-temperature molten liquid state to transform it into a solid state at room temperature.

Method for producing a ferro-molybdenum alloy according to the present invention having the above configuration and action,

The process is shortened by dissolving powder, agglomerates or a mixture of mixed iron oxide and molybdenum oxide and hydrogen reduction to produce a ferro-molybdenum alloy, and a material cost (aluminum, slag forming agent, Complexing agent, etc.), the investment cost of environmental pollution prevention facilities can be reduced, and labor costs can be reduced by reducing labor costs.

In addition, it prevents the occurrence of safety accidents by eliminating explosive thermite reaction, prevents the incorporation of impurities, increases the molybdenum recovery rate, and provides the effect of eliminating waste such as slag and waste casting sand.

In addition, it is possible to secure an excellent quality of homogeneous composition and to reduce the density of ingots, thereby facilitating the diffusion of ferro-molybdenum alloy into the molten metal in the steelmaking process.

Method for producing a ferro-molybdenum alloy of the present invention for achieving the above object,

A mixing step of mixing the powder, the lump or the mixed iron oxide and molybdenum oxide;

Dissolving step of first heating up to a certain temperature to dissolve the mixture into a liquid state;

A reduction step of reducing by injecting hydrogen gas into the dissolved mixture;

And a cooling step of cooling and solidifying the ferro-molybdenum alloy in the high-temperature molten liquid state to transform it into a solid state at room temperature.

At this time, the iron oxide is,

FeO, Fe ₃ O ₄ , Fe ₂ O ₃ Or a mixture thereof and molybdenum oxide is characterized in that MoO ₃ , MoO ₂ or a mixture thereof.

At this time, the size of the iron oxide powder or agglomerate is 0.1 μm ~ 100 mm, the size of the molybdenum oxide powder or agglomerate is characterized in that 0.1 μm ~ 100 mm.

At this time, in the dissolution step,

Temperature and time for dissolving the mixture is characterized in that it is maintained for 10 to 60 minutes at 700 ~ 800 ⁰ C.

At this time, in the reduction step,

The mixture of the liquid state is characterized by maintaining a hydrogen atmosphere for 3 to 10 hours at 700 ~ 800 ⁰ C.

At this time, in the reduction step,

The mixture of the liquid state is heated to 900 ~ 1200 ⁰ C and characterized by maintaining a hydrogen atmosphere for 2 to 5 hours.

Hereinafter, an embodiment of the method for producing a ferro-molybdenum alloy according to the present invention will be described in detail.

1 is a flow chart schematically showing a method for manufacturing a ferro-molybdenum alloy according to an embodiment of the present invention.

As shown in Figure 1, the method for producing a ferro-molybdenum alloy of the present invention,

A mixing step of mixing the powder, the lump or the mixed iron oxide and molybdenum oxide;

Dissolving step of first heating up to a certain temperature to dissolve the mixture into a liquid state;

A reduction step of reducing by injecting hydrogen gas into the dissolved mixture;

And a cooling step of cooling and solidifying the ferro-molybdenum alloy in the high-temperature molten liquid state to transform it into a solid state at room temperature.

In the step of mixing, the powder, agglomerates or 0.1 mol m to 100 mm in size, and mixed iron oxide and molybdenum oxide are weighed so as to have a predetermined composition ratio, and then mixed in a general mixer for 1 to 30 minutes.

In the dissolving step, a mixed material of iron oxide and molybdenum oxide is charged to an Inconel crucible and maintained at 700 to 800 ⁰ C for 10 to 60 minutes to dissolve the mixture into a liquid state.

In the hydrogen reduction step, the liquid mixture is maintained at 700 to 800 ⁰ C for 3 to 10 hours, or the liquid mixture is heated to 900 to 1200 ⁰ C for 2 to 5 hours. The ferro-molybdenum alloy can be prepared if maintained.

In the cooling step, the ferro-molybdenum alloy in a high temperature molten liquid state is cooled and solidified to transform a phase into a solid state at room temperature.

In other words, powder, agglomerate or mixed iron oxide and molybdenum oxide are mixed in an Inconel crucible, charged in a hydrogen reduction reactor, and then maintained at 700 to 800 degrees Celsius for 10 to 60 minutes to dissolve the mixed raw material into a liquid state. It will exist.

Hydrogen gas is added for 3 to 10 hours while maintaining the molten liquid at 700 to 800 degrees Celsius, or hydrogen gas is added while the dissolved liquid mixture is heated to 900 to 1200 degrees Celsius and maintained for 2 to 5 hours. When the molten liquid is reduced, a ferro-molybdenum alloy is produced.

Example 1

Iron oxide and molybdenum oxide were used in a powder having a particle size of about 1 μm, and the mixing ratio was iron oxide; Molybdenum oxide = 1; The basis weight was 4.

The mixed powder was charged into an Inconel crucible, and the Inconel crucible was placed at the center of the electric furnace in which the hydrogen gas atmosphere can be controlled, and the temperature was raised to 800 ⁰ C, and dissolved in an atmospheric atmosphere for 20 minutes. Thereafter, while maintaining the temperature again to 1150 ⁰ C, hydrogen gas was added for 5 hours and cooled to prepare a black silver ferro-molybdenum alloy.

[Example 2]

Iron oxide and molybdenum oxide were mixed with a powder of about 1 μm particle size and agglomerates of about 10 mm particle size, and the mixing ratio was iron oxide; Molybdenum oxide = 1; The basis weight was 2.

Loading the composite material of denyum iron oxide and molybdenum in Inconel crucible, and to position the Inconel crucible in the center in the in the electrical control of a hydrogen gas atmosphere as possible and raising the temperature to 800 ⁰ C and then dissolved by keeping it in the air for 60 min. Hydrogen gas was added at a temperature and maintained for 10 hours, followed by cooling to prepare a black silver ferro-molybdenum alloy.

Example 3

Iron oxide and molybdenum oxide were made from a mixture of about 1 μm particle size powder and agglomerates of about 30 mm particle size. The mixing ratio was iron oxide; Molybdenum oxide = 1; The basis weight was 4.

A mixed material of iron oxide and molybdenum oxide was charged to an Inconel crucible, and the Inconel crucible was placed at the center of an electric furnace in which hydrogen gas atmosphere can be controlled, and the temperature was raised to 800 ⁰ C and held in the air for 60 minutes to dissolve.

Then it added hydrogen gas to re-heated to 1000 ⁰ C and one of the cooled black silver Ferro after keeping for 5 hours, was prepared alloy molybdenum.

The density of the ferro-molybdenum alloys prepared in Examples 1, 2 and ^{3 described above} was measured to be 6.5 ~ 7.5 g / cm ³ is less than the density of the ferro-molybdenum alloy prepared by the thermite reaction It has a small value and shows the density of steel making and the approached value.

Also, electron micrographs and X-ray diffraction patterns of the wavefront of the ferro-molybdenum alloy prepared in Example 1 are as shown in FIGS. 2 and 5, respectively.

On the other hand, electron micrographs and X-ray diffraction patterns of the wavefront of the ferro-molybdenum alloy prepared by the conventional thermite reaction for comparison is shown in FIG. 4 and FIG.

As shown in FIG. 2 and FIG. 5, the ferro-molybdenum alloy according to the present invention was found to have a small particle size and low density due to the presence of pores in the tissue.

5 and 7, the X-ray diffraction pattern is slightly different but the crystal structure is the same.

As a result, the process is shortened by dissolving powder, agglomerates or a mixture of iron oxide and molybdenum oxide mixed together and hydrogen-reducing to produce a ferro-molybdenum alloy by the above-described manufacturing method, and the material cost to be added to the extracurricular (Aluminum, slag forming agent, complexing agent, etc.) can be saved, investment cost of environmental pollution prevention facilities can be saved, and labor costs can be reduced by reducing labor costs, and explosive thermite reactions are eliminated. It prevents the occurrence of safety accidents, prevents the mixing of impurities, increases the recovery rate of molybdenum, eliminates the generation of wastes such as slag and waste casting sand, secures excellent quality of homogeneous composition and low density of ingot. In a furnace steelmaking process, ferro-molybdenum alloys can facilitate melt diffusion into molten metal.

Those skilled in the art to which the present invention pertains as described above may understand that the present invention may be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not restrictive.

The scope of the invention is indicated by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the invention. do.

The method for producing a ferro-molybdenum alloy of the present invention,

The process is shortened by dissolving powder, agglomerates or a mixture of mixed iron oxide and molybdenum oxide and hydrogen reduction to produce a ferro-molybdenum alloy, and a material cost (aluminum, slag forming agent, Complexing agent, etc.), the investment cost of the environmental pollution prevention facility can be reduced, and the labor cost can be reduced, thereby reducing the manufacturing cost.

1 is a flow chart schematically showing a method for manufacturing a ferro-molybdenum alloy according to an embodiment of the present invention.

Figure 2 is an electron micrograph of the structure of the wavefront of the ferro- molybdenum alloy prepared by the method for producing a ferro-molybdenum alloy according to an embodiment of the present invention.

FIG. 3 is an electron microscopic picture of a wavefront of a sample cooled after dissolving a mixture of iron oxide and molybdenum oxide prepared by a method for preparing a ferro-molybdenum alloy according to an embodiment of the present invention.

4 is an electron micrograph of a wavefront of a ferro-molybdenum alloy prepared by the conventional thermite reaction.

FIG. 5 is a diagram illustrating an X-ray diffraction pattern of a ferro-molybdenum alloy prepared by a method of manufacturing a ferro-molybdenum alloy according to an embodiment of the present invention.

6 is an X-ray diffraction pattern of a sample cooled after dissolving a mixture of iron oxide and molybdenum oxide prepared by a method for preparing a ferro-molybdenum alloy according to an embodiment of the present invention. Pattern).

FIG. 7 is a diagram illustrating an X-ray diffraction pattern of a ferro-molybdenum alloy prepared by a conventional thermite reaction.

Claims (6)

delete delete A mixing step of mixing the powder, the lump or the mixed iron oxide and molybdenum oxide; Dissolving step of first heating up to a certain temperature to dissolve the mixture into a liquid state; A reduction step of reducing by injecting hydrogen gas into the dissolved mixture; A cooling step of transforming the ferro-molybdenum alloy in the molten liquid state of the high temperature molten liquid to transform to a solid state at room temperature; The size of the iron oxide and molybdenum oxide is 0.1 μm ~ 100 mm manufacturing method of ferro-molybdenum alloy, characterized in that. A mixing step of mixing the powder, the lump or the mixed iron oxide and molybdenum oxide; Dissolving step of first heating up to a certain temperature to dissolve the mixture into a liquid state; A reduction step of reducing by injecting hydrogen gas into the dissolved mixture; Cooling and solidifying the ferro- molybdenum alloy in the molten liquid state of the high temperature molten state transformed into a solid state at room temperature; In the dissolution step, Method for producing a ferro-molybdenum alloy, characterized in that the temperature and time for dissolving the mixture is maintained for 10 to 60 minutes at 700 ~ 800 ⁰ C. A mixing step of mixing the powder, the lump or the mixed iron oxide and molybdenum oxide; Dissolving step of first heating up to a certain temperature to dissolve the mixture into a liquid state; A reduction step of reducing by injecting hydrogen gas into the dissolved mixture; A cooling step of transforming the ferro-molybdenum alloy in the molten liquid state of the high temperature molten liquid to transform to a solid state at room temperature; In the reduction step, Method for producing a ferro- molybdenum alloy, characterized in that the mixture of the liquid state to maintain a hydrogen atmosphere for 3 to 10 hours at 700 ~ 800 ⁰ C. A mixing step of mixing the powder, the lump or the mixed iron oxide and molybdenum oxide; Dissolving step of first heating up to a certain temperature to dissolve the mixture into a liquid state; A reduction step of reducing by injecting hydrogen gas into the dissolved mixture; A cooling step of transforming the ferro-molybdenum alloy in the molten liquid state of the high temperature molten liquid to transform to a solid state at room temperature; In the reduction step, Method of producing a ferro- molybdenum alloy, characterized in that the mixture is maintained in a hydrogen state for 2 to 5 hours after heating the mixture in the liquid state to 900 ~ 1200 ⁰ C.

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