KR101112984B1 - Method for estimating alloy density of molten ferro-manganese - Google Patents

Abstract

The present invention relates to a method for evaluating the alloy density of molten ferro-manganese in the production of ferro-manganese, the first step of obtaining a relational expression of the density value according to the molten iron of molten pure iron, and the alloy density value of the molten ferro-manganese according to the molten temperature A second step of obtaining a relational equation, and a third step of defining a relational expression further comprising Mn composition dependency coefficients of an arbitrary Mn content and alloy density between molten ferro-manganese in the relational expression of the first step; And a fourth step of calculating the Mn composition dependency coefficient of the alloy density between the molten ferro manganese in preparation for the relational expression of the third step, and the Mn composition dependency coefficient of the alloy density between the molten ferro manganese calculated in the fourth step. The technical summary of the alloy density evaluation method of the molten ferro-manganese comprising the fifth step of evaluating the alloy density of the molten ferro-manganese according to the Mn content and the melt temperature using the relationship equation Shall be.
According to the present invention, the alloy density measured according to the Mn composition and the melting temperature of the ferro-manganese containing low concentration of Mn during the smelting and refining process of ferro-manganese to evaluate the alloy density of ferro-manganese containing high concentration of Mn By providing a method, by accurately evaluating the alloy density of ferro-manganese, which was difficult to precisely measure due to the high vapor pressure and reactivity of Mn at high temperature in the production of ferro-manganese, ferro-manganese by accurately calculating the heat balance and the like using the evaluated density value The smelting and refining error rate of manganese can be improved.

Description

Method for evaluating alloy density of molten ferro-manganese {METHOD FOR ESTIMATING ALLOY DENSITY OF MOLTEN FERRO-MANGANESE}

The present invention relates to a method for evaluating the alloy density of molten ferro-manganese in the production of ferro-manganese, more specifically measured according to the Mn composition and melt temperature of the ferro-manganese containing low concentration of Mn during the smelting and refining process of ferro-manganese The alloy density is used to evaluate the alloy density of molten ferro-manganese containing a high concentration of Mn.

In the steel industry, the demand for high-purity metal manganese (Metal Mn) is increasing day by day as the production of high-grade steel and special steel such as high-strength steel, seismic steel sheet, and TWIP steel containing more than 10% of manganese for high processing.

The metal manganese is generally manufactured by a wet smelting method using electrolysis. The electrolytic method is complicated in the manufacturing process, such as mixing raw materials, filtration, pH control, while the recovery rate of metal manganese is low to 40 to 50%. In the case of sulfuric acid and sludge produced during the manufacturing process, the supply and demand will be unstable if environmental regulations are tightened in the future.

Therefore, in recent years, a method of manufacturing ferro-manganese of high purity that can replace the conventional manufacturing method of expensive metal manganese, which is complicated in manufacturing process and discharges environmental pollutants, has been researched and developed.

However, in order to improve the smelting and refining error rate of ferro-manganese, accurate density data of molten alloy of ferro-manganese is required in the process. Due to the high concentration of Mn contained in ferro-manganese, Due to vaporization, bubbles were generated inside the molten alloy, and it was very difficult to accurately measure the density of molten ferro-manganese.

Therefore, there has been a demand for an evaluation method capable of accurately measuring alloy density values of molten ferro-manganese to improve the smelting and refining error rates of ferro-manganese.

The present invention has been made to solve the above-mentioned problems, and accurately evaluate the alloy density value of the molten ferro-manganese, which was difficult to precisely measure due to the high vapor pressure and reactivity of Mn at a high temperature in the production of ferro manganese, and the evaluated density value It is an object of the present invention to provide a method for evaluating alloy density of molten ferro-manganese which can improve the smelting and refining error rate of ferro-manganese by accurately calculating the heat balance and the like by using a.

The present invention is a method for evaluating the alloy density of molten ferro-manganese in the production of ferro-manganese, the first step of obtaining a relational expression of the density value according to the melt temperature of molten pure iron, and the alloy density value of the molten ferro-manganese A second step of obtaining a relational expression, a third step of defining a relational expression further comprising Mn composition dependency coefficients of an arbitrary Mn content and alloy density between molten ferro-manganese in the relational expression of the first stage, the second step and The fourth step of calculating the Mn composition dependency coefficient of the alloy density between the molten ferro-manganese in preparation for the relationship of the third step, and the relation formula including the Mn composition dependency coefficient of the alloy density between the molten ferro-manganese calculated in the fourth step It provides a method for evaluating the alloy density of molten ferro-manganese comprising the fifth step of evaluating the alloy density of the molten ferro-manganese according to the content of Mn and the melt temperature.

In this case, the second step is also characterized in obtaining a relational expression of the alloy density value according to the melt temperature of the ferro-manganese containing Mn of 40% by weight or less.

In addition, the relational expression of the first step is also characterized by the following formula.

[Equation 1]

ρ _Fe = 7.215-11.6 × 10 ^-4 (T-1823).

(ρ _Fe : Density of molten pure iron (g / cm 3), T: Melting temperature (K))

In addition, the relational expression of the second step is characterized by the following formula.

&Quot; (2) "

ρ _{Fe-5% Mn} = 7.110-13.8 × 10 ^-4 (T-1823).

(ρ _{Fe-5% Mn} : alloy density of molten ferro-manganese containing 5% manganese (g / cm 3), T: melt temperature (K))

In addition, the relationship is also characterized by that derived using the constrained drop method (constrained drop method).

Furthermore, the relational expression of the third step is characterized by the following formula.

&Quot; (3) "

ρ _Fe-Mn = (7.215-α [Mn])-(11.6 + β [Mn]) x 10 ^-4 (T-1823).

(ρ _Fe-Mn : alloy density of molten ferro-manganese (g / cm 3), T: melt temperature (K)

 α, β: Mn component content coefficient, [Mn]: Mn component content (%))

In addition, the relational expression of the fifth step is also characterized by the following formula.

&Quot; (4) "

ρ _Fe-Mn = (7.215-0.021 [Mn])-(11.6 + 0.44 [Mn]) x 10 ^-4 (T-1823).

(ρ _Fe-Mn : alloy density of molten ferro-manganese (g / cm 3), T: melt temperature (K), [Mn]: Mn content (%))

According to the present invention, the alloy density measured according to the Mn composition and the melting temperature of the ferro-manganese containing low concentration of Mn during the smelting and refining process of ferro-manganese to evaluate the alloy density of the ferro-manganese containing high concentration of Mn By providing a method, by accurately evaluating the alloy density of ferro-manganese, which was difficult to precisely measure due to the high vapor pressure and reactivity of Mn at high temperature in the production of ferro-manganese, ferro-manganese by accurately calculating the heat balance and the like using the evaluated density value The smelting and refining error rate of manganese can be improved.

1 is a flow chart of the alloy density evaluation method of molten ferro-manganese according to the present invention.
Figure 2 is a schematic diagram of alumina crucible specially made for density measurement using the constrained drop method.
3 is a photograph comparing the images of the droplets obtained through the experiment, (a) is an image of the droplets obtained through the sessile drop method, (b) is a liquid obtained through the constrained drop method Enemy images.
Figure 4 is a graph showing the density value according to the temperature of the molten pure iron measured by the water droplet method.
5 is a graph showing the density value according to the temperature of the ferromanganese molten alloy containing 5% by weight of Mn measured by the water droplet method.
Figure 6 is a graph comparing the density value of the molten ferro-manganese alloy density evaluation according to the present invention, and the temperature-dependent density of the ferro-manganese molten alloy containing 80% by weight Mn actually measured by a static method.
Figure 7 is a graph showing the isodensity line according to Mn concentration and melt temperature using the evaluation formula of the alloy density evaluation method of molten ferro-manganese according to the present invention.

Hereinafter, a method for evaluating alloy density of molten ferro-manganese according to the present invention will be described in detail with reference to the accompanying drawings.

In order to evaluate the alloy density of molten ferro-manganese during the smelting and refining of ferro-manganese, as shown in the flow chart of FIG. 1, first, a relation of density values according to the melt temperature of molten pure iron that does not contain Mn components is described. Performing the first step (step S10) to obtain.

The density value of pure iron according to the melting temperature is described in various documents as shown in FIG. 4, and the density measurement method of molten metal is buoyancy method, static drop method, and water drop method. Since the method, constrained drop method, etc. can be referred to the various documents and the density measurement method can be used to measure the alloy density of molten ferro-manganese.

However, as shown in the droplet image of FIG. 3, in the case of (a) dissolved in the alumina plate by using the static method, the interface of the solid solution is not sure and the volume value is inaccurate. In the case of (b) using the soaking method in the specially manufactured alumina crucible of the solid solution, the density of solid solution can be measured relatively precisely than the static method, so that the density value can be measured using the soaking method among the various density measuring methods. It is preferable.

Therefore, when the density value of the molten pure iron according to the temperature is measured by the dropping method corresponding to one embodiment of the present invention, it appears as shown in the graph of FIG. 4. The value labeled 'Present work' is the density value measured by the water droplet method, and the other values represent the density values described in various documents, and the measurement error value was ± 0.44%.

When the graph of FIG. 4 is represented by a density formula according to temperature, it may be expressed by Equation 1 below.

[Equation 1]

ρ _Fe  = 7.215-11.6 × 10 ^-4 (T-1823).

(ρ _Fe : Density of molten pure iron (g / cm 3), T: melt temperature (K)

As shown in Equation 1, it can be seen that the temperature dependent coefficient of the molten pure iron density is 11.6 × 10 ⁻⁴ , and the density value is 7.215 at the melt temperature 1823K.

Of course, when the density value described in other documents or another density measuring method is used, Equation 1 may have a different value.

Next to the first step, a second step (step S20) of obtaining a relational expression of alloy density values according to the melting temperature of the molten ferro-manganese is performed. At this time, when the Mn content of the ferro-manganese exceeds 40% by weight, bubbles are generated in the molten alloy due to the vaporization of Mn due to the high vapor pressure of Mn in the hot melt, making it difficult to accurately measure the density. It is preferable to measure the alloy density value of the ferromangan content of 40 wt% or less.

As an embodiment of the present invention using a ferro manganese containing 5% by weight Mn by measuring the alloy density of the molten ferro-manganese according to the melt temperature by using the water droplet method is shown in the graph shown in Figure 5, the measurement error value ± 0.5%.

When the graph of FIG. 5 is represented by a density equation according to temperature, it may be expressed by Equation 2 below.

&Quot; (2) "

ρ _{Fe-5% Mn}  = 7.110-13.8 × 10 ^-4 (T-1823).

(ρ _{Fe-5% Mn} : Alloy density of molten ferro-manganese containing 5% manganese (g / cm 3), T: melting temperature (K))

As shown in Equation 2, it can be seen that the temperature dependent coefficient of the molten ferro-manganese alloy density is 13.8 × 10 ⁻⁴ , and the density value is 7.110 at the melt temperature 1823K. Of course, when using a ferro manganese having a different Mn content composition or using a different density measurement method, Equation 2 may have a different value.

Next to the second step, a third step (step S30) is performed to obtain a relationship equation further comprising Mn composition dependency coefficient of the content of the Mn and the alloy density of the molten ferro-manganese in the relationship equation of the first step.

That is, in order to calculate the dependency of the molten ferro-manganese alloy density value according to the Mn content, Equation 3 is defined as follows by using Equation 1 above.

&Quot; (3) "

ρ _Fe-Mn  = (7.215-α [Mn])-(11.6 + β [Mn]) × 10 ^-4 (T-1823).

(ρ _Fe-Mn  : Alloy density of molten ferro-manganese (g / cm 3), T: melt temperature (K)

 α, β: Mn component content coefficient, [Mn]: Mn component content (%))

In Equation 3, a portion of Mn composition dependency coefficient of the Mn content and the alloy density of the molten ferro-manganese is further added to Equation 1 above.

Next, a fourth step (step S40) of calculating the Mn composition dependency coefficient of the alloy density between the molten ferro-manganese is performed by comparing the relational expressions of the second and third steps with each other.

That is, ρ _{Fe-Mn in} Equation 3 in which 5% is substituted in ρ _{Fe-5% Mn} and [Mn] in Equation 2 By setting the same value, and comparing Equation 2 and Equation 3, the following two equations are derived.

[Equation 3-1]

7.110 = 7.215-5α

[Equation 3-2]

13.8 = 11.6 + 5β

The α value is 0.21 from Equation 3-1, and the β value is 0.44 from Equation 3-2.

Therefore, the following equation (4) can be obtained by inputting the α and β values calculated in the above equation (3).

&Quot; (4) "

ρ _Fe-Mn  = (7.215-0.021 [Mn])-(11.6 + 0.44 [Mn]) × 10 ^-4 (T-1823).

(ρ _Fe-Mn  : Alloy density of molten ferro-manganese (g / cm 3), T: melt temperature (K), [Mn]: Mn content (%))

Next, a fifth step of evaluating the alloy density of the molten ferro-manganese according to the Mn content and the melt temperature using Equation 4 including the Mn composition dependency coefficient of the alloy density of the molten ferro-manganese calculated in the fourth step (Step S50).

Equation (4) is an alloy density evaluation formula of molten ferro-manganese, and the temperature and Mn composition dependence are considered, and therefore, not only a low-concentration Mn-containing ferro-manganese molten alloy but also a high-concentration Mn-containing ferromanganese molten alloy exceeding 40% by weight. It can also be applied to the density evaluation of.

On the other hand, using the equation (4) shows the density line according to the Mn concentration and the melt temperature as shown in the graph of FIG. By using the isodensity line of FIG. 7, it is easy to know the approximate value of the alloy density of the molten ferro-manganese according to the component content of Mn contained in the ferro-manganese and the melt temperature.

Hereinafter, an embodiment of an alloy density evaluation method of molten ferro-manganese according to the present invention will be described with reference to the drawings. The embodiments described below are intended to illustrate the invention, and may be modified in various forms without departing from the spirit and scope of the invention.

Alumina crucibles having the shape and size of FIG. 2 were manufactured to measure the density value by using the water drop method to compensate for the uncertainty of the interface of the solid solution during the experiment using the sessile drop method. Of course, variations in the shape and size of the crucible are possible.

Using the alumina crucible, by measuring the density value in the molten pure iron molten iron in the range of 1800 ~ 1900K to obtain the equation (1), the melting temperature of ferro manganese containing 5% by weight of Mn by the water droplet method After measuring the alloy density value in the range of 1800 ~ 1900K to obtain the equation (2), the equation (3) including the Mn composition and Mn composition dependence coefficients (α, β) in Equation 1 is defined, In contrast to Equation 3, α value 0.21 and β value 0.44 were obtained. Subsequently, the α and β values were substituted in Equation 3 to derive Equation 4, which is an alloy density evaluation formula for molten ferro-manganese according to Mn composition and temperature. It was calculated, and the result of the calculation is shown as 'Present model calc' of FIG. 6 (linear portion).

In addition, in order to directly measure the molten alloy density value of the ferro-manganese containing high concentration of Mn and compare it with the density value measured by Equation 4, it contains 80% by weight of Mn using a static method using an alumina plate. The molten alloy density value of one ferro manganese was measured, and the result of the measurement was shown as' Present work (SD) of FIG. 6 (square point).

Dotted lines or dashed lines shown above and below the straight line in FIG. 6 represent an error of ± 10% per square, as shown in FIG. 6, without using the molten ferro-manganese alloy density evaluation method according to the present invention. When the molten alloy density value of the ferro-manganese containing a high concentration of Mn was obtained, the evaluation equation according to the present invention showed an error of 10 to 40%.

This is considered to be due to the bubbles generated inside due to the high vapor pressure of Mn, in this case it is difficult to obtain a precise density value due to the error. Therefore, when measuring the density value of the alloy density of molten ferro manganese by the evaluation formula by this invention, a more accurate measured value can be obtained.

The alloy density evaluation method of the molten ferro-manganese according to an embodiment of the present invention is applicable to the density evaluation of not only the ferro-manganese alloy of Fe-Mn, but also other binary alloys.

While the present invention has been described above, it will be readily understood by those skilled in the art that various modifications and variations are possible without departing from the spirit and scope of the claims set out below.

Claims (7)

In the method for evaluating the alloy density of molten ferro-manganese in the production of ferro-manganese,
A first step of obtaining a relation of density values according to the molten iron temperature of molten pure iron;
A second step of obtaining a relation of alloy density values according to the molten ferro-manganese melting temperature;
A third step of defining a relationship in which the Mn composition dependency coefficient of the content of arbitrary Mn and the alloy density between the molten ferro-manganese is further included in the relationship of the first step;
A fourth step of calculating a Mn composition dependency coefficient of the alloy density between the molten ferro-manganese in preparation for the relational expressions of the second and third steps;
Melting ferro includes a fifth step of evaluating the alloy density of the molten ferro-manganese according to the content of Mn and the melt temperature by using the relation formula including the Mn composition dependency coefficient of the alloy density of the molten ferro-manganese calculated in the fourth step Method for assessing alloy density of manganese. The method of claim 1,
The second step is a method for evaluating the alloy density of the molten ferro-manganese, characterized in that to obtain a relation of the alloy density value according to the melt temperature of the ferro-manganese containing 40% by weight or less Mn. The method of claim 1,
The relational formula of the first step is the alloy density evaluation method characterized in that the following formula.
[Equation 1]
ρ _Fe = 7.215-11.6 × 10 ^-4 (T-1823).
(ρ _Fe : Density of molten pure iron (g / cm 3), T: Melting temperature (K)) The method of claim 1,
The relationship formula of the second step is the alloy density evaluation method of the molten ferro-manganese, characterized in that consisting of the following formula.
&Quot; (2) "
ρ _{Fe-5% Mn} = 7.110-13.8 × 10 ^-4 (T-1823).
(ρ _{Fe-5% Mn} : alloy density of molten ferro-manganese containing 5% manganese (g / cm 3), T: melt temperature (K)) The method according to claim 3 or 4,
The relational formula is a method for evaluating the alloy density of molten ferro-manganese, characterized in that derived using the constrained drop method (constrained drop method). The method of claim 1,
The relational formula of the third step is the alloy density evaluation method of the molten ferro-manganese, characterized in that consisting of the following formula.
&Quot; (3) "
ρ _Fe-Mn = (7.215-α [Mn])-(11.6 + β [Mn]) x 10 ^-4 (T-1823).
(ρ _Fe-Mn : alloy density of molten ferro-manganese (g / cm 3), T: melt temperature (K)
α, β: Mn component content coefficient, [Mn]: Mn component content (%)) The method of claim 1,
The relationship formula of the fifth step is the alloy density evaluation method of the molten ferro-manganese, characterized in that consisting of the following formula.
[Equation 4]
ρ _Fe-Mn = (7.215-0.021 [Mn])-(11.6 + 0.44 [Mn]) x 10 ^-4 (T-1823).
(ρ _Fe-Mn : alloy density of molten ferro-manganese (g / cm 3), T: melt temperature (K), [Mn]: Mn content (%))

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