KR101889163B1 - Manufacturing method for glass-bead of iron-chrome alloy iron - Google Patents

Abstract

The present invention relates to a process for the production of glass-beads for the analysis of the content of trains contained in Fe-Cr ferroalloys.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing an Fe-Cr alloy iron-glass bead,

The present invention relates to a method for producing glass-beads for analyzing the content of trains contained in Fe-Cr alloyed iron by fluorescent X-rays.

In steel mills, steel elements are adjusted during the steelmaking process, or alloyed iron is put into molten steel for deoxidization or desulfurization of steel. At this time, it is necessary to know precisely the content of ferroalloy in order to calculate the amount of trace elements in the steel to control the steel properties. Therefore, rapid and accurate analysis of ferroalloy samples is a very important factor to produce high quality steels.

Conventional method for the analysis of ferroalloys involves melting ferroalloys directly with hydrochloric acid, nitric acid, hydrofluoric acid, or melting them with molten salts, dissolving them in acid, and analyzing them by gravimetric method, UV coloring method or inductive plasma emission spectroscopy Method and a method of pulverizing alloyed iron using a ball mill and then press-molding it into a pellet state and analyzing it by fluorescent X-ray.

Among them, the wet analysis method has a disadvantage in that the analysis result is accurate, but the preprocessing process is complicated according to the elemental elements, so that the analysis time is long and the analysis process is difficult.

On the other hand, the fluorescent X-ray analysis method by press molding has the advantage of rapidly analyzing various elements at the same time. However, the grain size effect due to the variation of the grain size of the ferroalloy itself, Due to the mineral effect caused by the wet analysis.

Meanwhile, a glass bead method using an electric furnace has been devised to solve the above problems. This has the effect of drastically improving the accuracy of the quantitative analysis because it is possible to remove the grain size effect or the mineral effect when the alloy iron is made into glass beads.

In particular, as the technology has recently been developed in the form of a combination of a temperature programming technique and an electric furnace, an environment that can be manufactured faster than the conventional glass bead manufacturing time has been established.

However, when glass beads made of Fe-Cr alloy steel having a particle size of about 100 탆 are produced, the metal components contained in the alloy iron easily form an alloy with the crucible made of platinum, thereby increasing the wear of the crucible and shortening the life of the crucible There is a concern that accurate composition analysis may become difficult.

That is, when using a known Fe-Cr bead manufacturing method, there is a problem that a calibration curve for damage to the platinum crucible and analysis of the X-ray fluorescence composition can not be secured.

Korean Patent Publication No. 1998-0049993

One aspect of the present invention is to provide a method for rapidly producing a homogeneous Fe-Cr alloy iron-glass bead without damaging the platinum crucible in the production of the Fe-Cr alloy iron-glass bead.

One aspect of the present invention is a method for producing an Fe-Cr alloy iron-glass bead from a flux, an oxidant, a co-oxidant, and a stripper, wherein the oxidant is lithium carbonate (Li ₂ CO ₃ ) (V ₂ O ₅ ). The present invention also provides a method for producing an Fe-Cr alloy iron-glass bead.

According to the present invention, it is possible to rapidly produce homogeneous Fe-Cr alloy iron-glass beads without damaging the platinum crucible.

In addition, the Fe-Cr alloy iron-bead of the present invention can be suitably used as a sample in fluorescence X-ray analysis.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a photograph showing the shape of an Fe-Cr alloy iron glass bead (Example (a), (b) Comparative Example 1) manufactured according to an embodiment of the present invention.
FIG. 2 is a photograph showing a state of a platinum crucible after transferring a melt in a platinum crucible to a mold according to an embodiment of the present invention (corresponding to the embodiment).

The inventors of the present invention have devised a method for quickly producing Fe-Cr alloy iron-glass beads while solving the problems of the existing glass bead method as a method for analyzing the composition of Fe-Cr alloy iron.

As a result, it has been confirmed that Fe-Cr alloy iron-glass beads can be produced quickly without damaging the platinum crucible when controlling the components added in the production of the glass-bead and optimizing the charging conditions, I have come to completion.

Hereinafter, the present invention will be described in detail.

A method of manufacturing an Fe-Cr alloy iron-glass bead according to one aspect of the present invention includes the steps of: a) charging the flux into a platinum crucible; b) charging the mixture of the oxidizing agent, the auxiliary oxidizing agent and the Fe-Cr alloy iron into the platinum crucible; c) further adding flux to the top of the flux and mixture; d) charging a stripper agent into the platinum crucible; e) heating and melting the platinum crucible in an electric furnace to produce a melt; And f) transferring the melt to a heated mold and cooling to produce glass beads.

The present invention relates to a method for producing a sample for analyzing the composition of Fe-Cr alloy iron, that is, a method for producing glass-bead. The Fe-Cr alloy iron to be analyzed is difficult to oxidize as the Cr content is high, High temperature is required. In this case, there arises a problem that alloying phenomenon easily occurs with the platinum crucible during the production of the glass-bead, and the Fe-Cr particles which are not melted in the beads remain after the bead production.

Therefore, it is preferable that the content of Cr in the Fe-Cr alloy iron does not exceed 80% by weight, and the Fe-Cr alloy iron is preferably pulverized to have a grain size of 100 탆 or less using a ball mill or the like.

If the particle diameter exceeds 100 탆, the internal remnants remain during the production of the glass-bead, and the beads thus produced may be broken.

In the present invention, the weight (amount of use) of the Fe-Cr alloy iron used for producing the Fe-Cr alloy iron-glass bead in the present invention is not particularly limited and may be suitably selected in consideration of the size of the platinum crucible have.

The flux used in the present invention is preferably lithium tetraborate (Li ₂ B ₄ O ₇ ). When Li ₂ B ₄ O ₇ is used as the flux, the phenomenon of forming a film on the surface by absorbing moisture after glass-bead production does not occur as compared with the case where another kind of flux is used. Further, since the melting point of the flux is 950 캜, the preliminary oxidation temperature can be increased and the preliminary oxidation time can be shortened.

Here, the pre-oxidation means a process in which the Fe-Cr alloy iron is oxidized by the oxidant and the auxiliary oxidant which are added to the upper portion of the flux after charging the flux.

The flux is preferably charged in an amount of 80 to 100 times the weight of Fe-Cr alloy steel. If the amount of the flux is less than 80 times, the Fe-Cr alloy iron is not sufficiently melted, thereby damaging the platinum crucible, and particles remain inside the bead. On the other hand, when the amount exceeds 100 times, the Fe-Cr alloy iron content in the glass-bead becomes too small, and the probability of error in the component analysis increases.

The amount of the flux refers to the total amount added in the production of the Fe-Cr alloy iron-glass bead of the present invention, specifically, the sum of the amounts of the upper solvent and the lower solvent.

An oxidizing agent for oxidizing the Fe-Cr alloy iron is mixed with the Fe-Cr alloy iron prior to reacting the flux with the Fe-Cr alloy iron.

The oxidizing agent is not particularly limited as long as it is a material capable of oxidizing Fe-Cr alloy iron at a temperature lower than the melting point of the flux, but lithium carbonate (Li ₂ CO ₃ ) can be preferably used.

The oxidizing agent decomposes at about 700 ° C and oxidizes the Fe-Cr metal. The reason why the oxidation reaction of the oxidizing agent must occur at a temperature lower than the melting point of the flux is to prevent contact between the unoxidized Fe-Cr alloy iron and the platinum crucible.

The oxidizing agent is preferably mixed in an amount of 15 to 20 times by weight based on Fe-Cr alloy iron. If the amount of the oxidizing agent is less than 15 times, complete oxidation of the Fe-Cr alloy iron can not be expected and an alloy with the platinum crucible may be generated. On the other hand, if the amount exceeds 20 times, crystallization of the glass-bead may be caused or it may be difficult to obtain the accurate X-ray intensity of the Fe-Cr alloy steel.

On the other hand, the present invention can further mix the auxiliary oxidizing agent to supplement the oxidation of the Fe-Cr alloy iron while preventing the alloy with the platinum crucible.

As the auxiliary oxidizing agent, it is preferable to use vanadium oxide (V ₂ O ₅ ). This starts melting at about 690 占 폚 and acts simultaneously with the oxidizing agent to oxidize the Fe-Cr alloy iron. In addition, it protects the platinum crucible so that the unoxidized Fe-Cr alloy iron does not react with the platinum.

The auxiliary oxidizing agent is preferably mixed in an amount of 2 to 10 times by weight based on the weight of the Fe-Cr alloy steel. If the amount of the auxiliary oxidizing agent is less than 2 times, the effect of protecting the platinum crucible is insufficient and damage to a part of the platinum crucible may occur. On the other hand, if the amount exceeds 10 times, crystallization of the glass-bead may be caused, or it may be difficult to obtain the accurate X-ray intensity of the Fe-Cr alloy steel.

The oxidizing agent and the auxiliary oxidizing agent whose contents are controlled as described above are mixed with the Fe-Cr alloy iron and charged into the upper center of the flux (lower flux) charged into the platinum crucible. Then, It is preferable to further add a flux (upper flux) onto the substrate.

The upper center of the flux refers to a groove formed at the center of the initially added flux. When the mixture containing the Fe-Cr alloy iron, the oxidizing agent and the auxiliary oxidizing agent is introduced, the groove is formed so as not to be in contact with the platinum crucible .

At this time, the flux is the same as mentioned above, and the same amount can be used. That is, in the present invention, half of the total weight of the flux used for preparing the Fe-Cr glass bead can be used for the first time in the first platinum crucible and the other half can be used after charging the mixture. However, the present invention is not limited thereto, and the content of the flux to be charged may be adjusted in stages according to the weight of the mixture.

Thereafter, in the present invention, it is preferable to load the stripping agent into the platinum crucible.

The releasing agent is added in order to allow the produced glass beads to be easily separated from the mold without breaking, and the releasing agent is preferably one or more of potassium iodide (KI), lithium iodide (LiI) and lithium bromide (LiBr) Do.

The releasing agent is preferably charged in an amount of 2 to 4 times the weight of the Fe-Cr alloy steel. If the amount of the exfoliating agent is less than 2 times, the fluidity is decreased in the subsequent heating and melting step, so that a complete form of glass-bead can not be obtained. On the other hand, if the amount exceeds 4 times, the flowability of the glass-bead excessively increases, so that the glass-bead shape optimized for the composition measurement can not be obtained, and the interference of the elements used in the releasing agent increases, Which is difficult to obtain.

As described above, it is preferable that the flux, the oxidizing agent, the auxiliary oxidizing agent, and the stripping agent are all charged into the platinum crucible in a stepwise manner, and then the platinum crucible is heated and melted to produce a melt.

The heating is preferably performed in a stepwise manner. Specifically, the heating is performed in a temperature range of 800 to 900 DEG C and then a heat treatment is performed for 40 to 80 minutes. After the first heating, the platinum crucible is heated to 1100 to 1150 DEG C, And a second heating step of performing heat treatment for 30 minutes to 30 minutes.

In the first heating step, the Fe-Cr alloy iron is oxidized through the oxidation reaction with the oxidizing agent and the auxiliary oxidizing agent. At this time, the oxidizing agent having a lower melting point than the Fe-Cr alloy iron and the auxiliary oxidizing agent are melted first, And oxidation reaction. Thus, while the Fe-Cr alloy iron is oxidized in the first heating step, the auxiliary oxidant together with the flux serves to prevent the Fe-Cr alloy iron from contacting the platinum crucible. Then, in the first heating step, the releasing agent is melted together and mixed with the oxidized Fe-Cr alloy iron.

The first heating step is preferably performed at 800 to 900 ° C. If the temperature is lower than 800 ° C., the oxidation reaction of the oxidizing agent and the Fe-Cr alloy iron does not completely take place. On the other hand, when the temperature exceeds 900 ° C, there is a problem that the Fe-Cr alloy iron powder and the flux are scattered by melting to the flux, and the Fe-Cr alloy iron directly contacts the platinum crucible to form an alloy.

In the first heating in the above temperature range, if the time is less than 40 minutes, the oxidation reaction of the oxidizing agent and the Fe-Cr alloy iron does not completely take place. On the other hand, if it exceeds 80 minutes, the heating is continued even after the oxidation reaction is terminated, so that the thermal efficiency of the production process is lowered, and the volatilization amount of the release agent becomes large, Can not be obtained.

After completing the first heating step, it is preferable to perform the second heating step at a higher temperature. In the second heating step, the flux surrounding the Fe-Cr alloy iron oxidized in the first heating step is preferably melted. The Fe-Cr alloy iron oxidized in the first heating step, the melted oxidizing agent, the auxiliary oxidizing agent and the stripping agent together with the flux are mixed together and completely melted.

 The second heating step is preferably performed at a temperature of 1100 to 1150 ° C. If the second heating temperature is less than 1,100 占 폚, there is a problem that the time for melting the Fe-Cr alloy iron takes a long time or the unmelted residue is not completely melted. On the other hand, when the temperature exceeds 1150 ° C, the reaction may occur rapidly and may be ejected out of the platinum crucible, resulting in a decrease in thermal efficiency. In addition, abrupt volatilization of the release agent and the flux occurs, which makes it difficult to obtain accurate X-ray intensity of Fe-Cr alloy iron.

In the second heating in the above-mentioned temperature range, if the time is less than 20 minutes, there is a fear that unfused residue will remain, while if it exceeds 30 minutes, the melt will lose its cohesion and crystallization may occur . That is, despite the introduction of the stripping agent, after cooling, it strongly adheres to the crucible and becomes difficult to separate. In addition, there is a risk that the glass-bead surface is split and can not be used for X-ray analysis.

On the other hand, in carrying out the second heating step for a certain period of time in the above-mentioned temperature range, it is preferable to tilt the platinum crucible at the same time as heating and stir the inside thereof. This is for producing a glass bead having homogeneous components.

The melt obtained by completing the second heating step may be transferred to a heated mold and cooled to produce Fe-Cr class-beads.

It is preferable to preheat the mold in order to prevent rapid cooling of the melt upon transfer of the molten material into the mold. At this time, the heating temperature is preferably about 1100 to 1150 ° C.

Further, in order to maintain the uniform composition of the components, the transfer of the melt is preferably performed while maintaining the temperature state during the second heating step, and preferably, the melt is stirred. At this time, the stirring speed is preferably slower than the stirring speed in the second heating step. This is to prevent the melt from being splashed to the outside of the mold during delivery.

After transferring the melt to the heated mold according to the above, it is preferable that the mold is cooled using a cooling device. The cooling device is not particularly limited. For example, a fan can be used. In this case, it is preferable to cool the fan by slowing the fan speed by about 50% as compared with the conventional bead manufacturing method. This is because stress may concentrate in the glass-bead due to rapid cooling, resulting in cracking.

Hereinafter, the present invention will be described more specifically by way of examples. It should be noted, however, that the following examples are intended to illustrate and specify the present invention, but not to limit the scope of the present invention. And the scope of the present invention is determined by the matters described in the claims and the matters reasonably deduced therefrom.

( Example )

Fe-Cr alloy iron-glass beads were prepared using the fluxes, oxidants, auxiliary oxidants and exfoliants shown in Table 1 below.

Specifically, after 4 g of flux was charged into a platinum crucible, a mixture of 2 g of an oxidizing agent, 0.5 g of a co-oxidant and 0.10 g of Fe-Cr alloy iron (particle size of 100 탆 or less) Respectively. Then, 4 g of flux was further charged to cover both the mixture and the flux, and then 0.2 g of the release agent was charged. Then, the platinum crucible was placed in an electric furnace and heated, melted and cooled under the conditions shown in Table 3 to prepare Fe-Cr alloy iron-glass beads (illustrative).

Sample type Content (g) Remarks Fe-Cr alloy iron 0.10 - Li ₂ B ₄ O ₇ 4 Flux (top) Li ₂ B ₄ O ₇ 4 Flux (top) Li ₂ CO ₃ 2 Oxidant V ₂ O ₅ 0.5 Auxiliary oxidant LiBr 0.2 remover

For comparison, Fe-Cr alloy iron-glass beads were prepared by heating and cooling under the conditions shown in Table 3 below using the compositions shown in Table 2 below.

Sample type Comparative Example 1
(Content, g) Comparative Example 2
(Content, g) Comparative Example 3
(Content, g) Remarks Fe-Cr alloy iron 0.10 0.10 0.10 - Li ₂ B ₄ O ₇ 4 4 4 Flux (top) Li ₂ B ₄ O ₇ 4 4 4 Flux (bottom) Li ₂ CO ₃ - 2 2 Oxidant LiNO ₃ 2 - - Other oxidizing agents V ₂ O ₅ 0.5 - 0.5 Auxiliary oxidant LiBr 0.2 0.2 0.1 remover

(In Table 2, Comparative Example 1 is an addition of an oxidizing agent different from that provided in the present invention, Comparative Example 2 is a state in which no auxiliary oxidizing agent is added, and Comparative Example 3 does not satisfy the present invention.

division Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Heat Heat Heat Heat Pour Cool Cool time
(Minutes: seconds) 60:00 16:00 8:00 4:00 0:19 1:15 3:30 Temperature (℃) 900 1150 1150 1150 1150 - - R.Speed
(Times / minute) 0 15 30 20 0 0 - RRPos
(Angle (°)) 0 20 40 45 0 0 - RFPos
(Angle (°)) 0 20 40 45 0 0 - FAN - - - - - - 50

(In Table 2, Step 1 corresponds to the first heating step, Step 2-4 corresponds to the second heating step, Step 5 corresponds to the step of transferring the melt to the mold, and Step 6-7 corresponds to the cooling step .

Also, R.Speed means the speed at which the platinum crucible is shaken back and forth per minute (that is, the number of times of shaking per minute) so that the melt is well mixed, and R.R.Pos and R.F.Pos mean the angle swinging back and forth.

FIG. 1 (a) is a photograph of Fe-Cr alloy iron-glass beads (examples) manufactured by satisfying all of the present invention, and it can be confirmed that glass-beads are homogeneously produced without internal residues.

Further, as shown in Fig. 2, it can be confirmed that the platinum crucible is not damaged even after the molten material is produced and transferred to the mold.

On the other hand, as shown in FIG. 1 (b), it can be confirmed that in Comparative Example 1, Fe-Cr alloy iron remained in the Fe-Cr alloy iron-glass bead. Although not separately shown, the same results were also obtained in Comparative Examples 2 and 3.

Claims (7)

A method for producing an Fe-Cr alloy iron-glass bead from a flux, an oxidizing agent, a co-oxidizing agent and a stripping agent,
Wherein the oxidizing agent is lithium carbonate (Li ₂ CO ₃ ), and the auxiliary oxidizing agent is vanadium oxide (V ₂ O ₅ ).
The method according to claim 1,
The method for producing the Fe-Cr alloy iron-glass bead
a) charging the flux into a platinum crucible;
b) charging the mixture of the oxidizing agent, the auxiliary oxidizing agent and the Fe-Cr alloy iron into the platinum crucible;
c) further adding flux to the top of the flux and mixture;
d) charging a stripper agent into the platinum crucible;
e) heating and melting the platinum crucible in an electric furnace to produce a melt; And
f) transferring the melt to a heated mold and cooling to produce glass beads
≪ RTI ID = 0.0 > Fe-Cr < / RTI >
3. The method of claim 2,
The flux is lithium tetraborate (Li ₂ B ₄ O ₇ )
Wherein the flux is charged in an amount of 80 to 100 times based on the weight of the Fe-Cr alloy steel, the amount of the flux charged in the step a) and the amount of the flux to be charged in the step c) Method of manufacturing beads.
3. The method of claim 2,
Wherein the oxidizing agent is mixed in an amount of 15 to 20 times the weight of the Fe-Cr alloy steel, and the auxiliary oxidizing agent is mixed in an amount of 2 to 10 times the weight of the Fe-Cr alloy steel, Method of manufacturing beads.
3. The method of claim 2,
Wherein the releasing agent is at least one of potassium iodide (KI), lithium iodide (LiI) and lithium bromide (LiBr), and is loaded in an amount of 2 to 4 times the weight of the Fe- Method of making glass beads.
3. The method of claim 2,
The heating of the e) is performed by heating the platinum crucible to a temperature ranging from 800 to 900 ° C. and then performing a heat treatment for 40 to 80 minutes and a second heating step of heating the platinum crucible to 1100 to 1150 ° C. after the first heating and then performing heat treatment for 20 to 30 minutes Wherein the heating step comprises heating the Fe-Cr alloy iron-glass bead.
3. The method of claim 2,
Wherein the Fe-Cr alloy iron has a particle diameter of 100 占 퐉 or less.

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