KR101362240B1 - A method for manufacturing process of ferromolybdenum - Google Patents

Abstract

Ferro molybdenum manufacturing method by the process step according to the present invention is prepared by mixing molybdenite (MoS ₂ ), iron powder (Fe powder), hematite (Fe ₂ O ₃ ), a reducing agent, a binder, a filler Pellet manufacturing step; A first reduction step of performing a heat reduction reaction under reduced pressure on the pellets prepared through the pellet manufacturing step; And a second secondary reduction step of blowing and exhausting hydrogen gas (H 2) to remove sulfur (S) from the pellet.

Description

A method for manufacturing process of ferromolybdenum

The present invention relates to a method for producing ferro molybdenum by the process singulation.

With the recent rise in raw material prices, the price of subsidiary materials for the production of alloy steels is increasing, and the price range of Fe-Mo used for the production of alloy steel containing Mo is very high. Establishment of a new process to manufacture is required.

In the conventional Fe-Mo manufacturing process, molybdenite (MoS ₂ ) is converted into MoO ₃ through roasting and leaching, and then MoO ₃ is mixed with hematite (Fe ₂ O ₃ ) to reduce the amount of the reducing agent. Fe-Mo is manufactured by the thermite reaction using phosphorus Al and Si. This method is a cause of manufacturing cost increase because the manufacturing process is complicated, and the price of other additives and reducing agent is high, in particular, there is a disadvantage that the price of the reducing agent Al, Si, etc. are very high. In addition, several mixtures such as Fe ₂ O ₃ , the starting material MoS ₂ , reducing agent, limestone, etc. are melted and reacted at the same time, so that they have some segregated structure and are difficult to crush and cut to a suitable size after the reaction. There are disadvantages.

In the conventional ferro molybdenum manufacturing process, molybdenite (MoS ₂ ) is converted to MoO ₃ through a process of roasting and leaching (MoS ₂ ) to produce high purity MoO ₃ .

Ferro molybdenum is prepared by thermite reaction using aluminum or silicon as a reducing agent by adding hematite (Fe ₂ O ₃ ), limestone, silicon, and the like, using MoO ₃ as a starting material.

Scheme 1 is a Fe-Mo manufacturing process by a conventional commercial process.

(반응식 1)

(Scheme 1)

However, the disadvantages of the existing process

First: Al, Si, etc. used as reducing agents are very expensive.

Secondly, the reaction is carried out by loading the reactants into a one-batch, so segregated -structure is likely to appear.

Third: there is a problem that takes a lot of time because after the reaction to crush and cut to a suitable size.

Therefore, the present invention intends to produce Fe-Mo by the process simplification by directly mixing the starting material MoS ₂ and iron oxide.

In addition, by manufacturing Fe-Mo by the process simplification, first, not only simplify the manufacturing process, second, by using C instead of Al, Si used as reducing agent, cost-effectiveness, third, after producing the pellet by a certain size Since Fe-Mo is manufactured, there is no need to segregate or cut. Fourth, the content of Fe and Mo can be easily controlled according to the capacity change.

Ferro molybdenum manufacturing method by the process step according to the present invention is prepared by mixing molybdenite (MoS ₂ ), iron powder (Fe powder), hematite (Fe ₂ O ₃ ), a reducing agent, a binder, a filler Pellet manufacturing step; A first reduction step of performing a heat reduction reaction under reduced pressure on the pellets prepared through the pellet manufacturing step; And a second secondary reduction step of blowing and exhausting hydrogen gas (H 2) to remove sulfur (S) from the pellet.

According to the present invention, the reducing agent is characterized in that the carbon (C).

According to the present invention, the binder is characterized in that any one or more of gelatin (Gelatines), starch (Sugars), molasses (Molarsses), Na2SiO3.

In addition, according to the present invention, the filler is characterized in that any one or more of wood flour (fiber), fibers (fiber), particles (particles).

According to the present invention, the reduction reaction temperature in the first reduction step is characterized in that 1360 ℃ to 1400 ℃.

In addition, according to the present invention, the reduced pressure in the first reduction step is characterized in that 10 to ² torr to 1 torr.

In addition, according to the present invention, the second reduction step is characterized in that the injection and exhaust of hydrogen gas (H2) for 3 hours at 298 ℃ to 300 ℃.

Therefore, in the present invention, there is an effect that the Fe-Mo can be produced by a simplified process by directly reducing the starting material by mixing MoS ₂ and iron oxide.

In addition, by manufacturing Fe-Mo by the process simplification, first, not only simplify the manufacturing process, second, by using C instead of Al, Si used as reducing agent, cost-effectiveness, third, after producing the pellet by a certain size Since Fe-Mo is manufactured, there is no need to segregate or cut. Fourth, the content of Fe and Mo can be easily controlled according to the capacity change.

1 is a flow chart of the Fe-Mo manufacturing method according to the present invention.
2 is a particle distribution diagram of MoS2 according to the present invention.
3 is an XRD analysis graph of Example 1 according to the present invention.
Figure 4 is a SEM photograph after the reaction of Example 1 according to the present invention.
5 is an EDS analysis result after the reaction of Example 1 according to the present invention.
6 is a reduction reactor and a vacuum control apparatus used in the present invention.
Figure 7 shows the change in the content of impurities as the vacuum degree at 1350 ° C of Example 4 according to the present invention.
Figure 8 shows the change in the content of impurities as the vacuum degree at 1400 ° C of Example 4 according to the present invention.
Figure 9 shows the change in the content of impurities as the vacuum degree at 1350 ° C of Example 5 according to the present invention.
Figure 10 shows the change in the content of impurities as the vacuum degree at 1400 ° C of Example 5 according to the present invention.
11 shows the content of impurities as the amount of Fe powder added at 1400 ° C. of Example 6 according to the present invention is changed.
12 shows the content of impurities as the amount of Fe powder added at 1400 ° C. of Example 7 according to the present invention is changed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 according to the present invention is a flow chart of the Fe-Mo manufacturing method according to the present invention.

As shown in Figure 1, the Fe-Mo manufacturing method according to the present invention is a pellet manufacturing step (S100) to produce a pellet by mixing the reactants including the raw material MoS2 through a ball mill and then compressed into a 100ton scale press Include.

The reactants include Fe, Fe ₂ O ₃ , reducing agent (C), gelatin (Gelatines), starch (Sugars), molasses (Molarsses), binders such as Na2SiO3, wood flour, fibers, It may include fillers such as particles.

At this time, as shown in the particle distribution diagram of MoS2 in FIG. 2, the particle distribution of the raw material was 30% for 100 mesh or more, 46% for 100 to 325mesh, and 24% for 325mesh or less. Particle distribution of the reactants plays an important role in creating voids for uniform reaction in the depth direction of the reactants, so it is very important to make proper particle distribution.

The thermal reduction reaction of the raw material and the reactant prepared in the pellet under reduced pressure is subjected to the first reduction step (S200).

In the first reduction step (S200), the reduction reaction is preferably carried out a heat reduction reaction at a reaction temperature of 1360 ℃ to 1400 ℃, the pressure at this time is preferably from 10 ^-2 torr to 1 torr.

In addition, the reduction reaction time is preferably 3 to 6 hours.

After the reduction reaction is completed in the first reduction step (S200), the secondary reduction step (S300) of blowing and exhausting H2 gas at 298 ° C to completely remove residual S remaining in the reactant after cooling to 298 ° C. Perform

The H2 gas blowing and exhaust time is preferably 3 hours.

Ferro-molybdenum (Fe-Mo) is produced by the method for producing ferro-molybdenum by the process singulation according to the present invention including a pellet manufacturing step (S100), the first, secondary reduction steps (S200, S300).

Example  One

To test the reducing conditions according to the temperature, MoS2 6g, Fe powder 1g, and the amount of reducing agent C were added in an amount of 1.2wt% excess to make pellets, and then, a high-temperature, high-vacuum reducing device diffused pump for high vacuum of 10 ^-5 torr or more. Reduction was carried out for 6 hours at 1360 ° C., 1380 ° C. and 1400 ° C. in a high vacuum state (diffusion pump), and then, after the reaction time was completed, furnace cooling was performed. The secondary reduction method in the furnace cooling was carried out to remove S remaining in the reactant after the primary reduction, and the residual S was removed as much as possible through H 2 gas blowing / exhaust at 300 ° C. for 3 hours.

Table 1 shows the impurity types and concentrations of the reactants after the reduction reaction in a high temperature and high vacuum atmosphere.

In the case of Mo, 74.53g and S were 20.1g, and the reduction was carried out according to the change of reaction temperature and the addition amount of reducing agent. As a result, most of S was reduced to <0.01g. appear.

In addition, it can be seen that most of the Fe and Mo oxide peaks (peak) also in the XRD analysis of FIG.

FIG. 4 shows SEM images after grinding to powder for analysis of other impurities in the reactants.

FIG. 5 shows the results of EDS analysis after grinding into powder for analysis of other impurities in the reactants.

As shown in FIGS. 4 and 5, it was found that most of the reactants consisted of Fe or Mo.

Example  2

In order to test the reducing conditions according to vacuum, 5 g of MoS2, 1 g of Fe powder, and reducing agent C were added in an amount of 1.5 wt% excess to prepare pellets, and then the reduction was performed using an atmosphere furnace instead of a high vacuum.

The high temperature atmosphere reduction reaction was carried out in the same manner as above, the experiment was carried out while blowing the Ar gas during the reduction reaction.

Table 2 shows the results of the reduction reaction with an atmosphere furnace.

Looking at the behavior of impurities in Table 2, it can be seen that the reduction is weak compared to the high vacuum equipment, because the vacuum suction force that can enhance the decomposition between the Mo-S during the reduction reaction is not acted. However, as the Fe (Iron) content increases, the content of some S decreases by more than half. This is because Fe (Iron) powder acts as an impurity of the reactants at high temperature, so that some surfaces are melted to prevent decomposition of S. It seems to have accelerated.

Example  3

In Example 3, an experiment was performed while increasing the degree of vacuum from atmospheric pressure to 10 × 10 ^-3 torr to determine the effect on the reducing conditions when manufacturing Fe-Mo according to the degree of vacuum. As shown in FIG. 6, the experimental apparatus was equipped with a device capable of controlling the degree of vacuum by modifying a general horizontal furnace.

The vacuum control device used in the present invention can be changed in the degree of vacuum of the reaction zone by a gate valve, as shown in Figure 6, the vacuum degree is accurately represented by two Piranha gauge.

Table 3 shows the ICP analysis after the reduction reaction according to the degree of vacuum.

First, the reaction temperature is 1350 ℃ and 1400 ℃ the amount of reducing agent C is added in excess of 1.2wt% and the reaction temperature is carried out for 6 hours as a result of the ICP analysis of the change of impurities as the vacuum degree changes from 100torr to 0.01torr. At 1350 ° C, the amount of impurities rapidly decreased as the degree of vacuum changed, but it did not reach the commercial S content. When the temperature was 1400 ° C or less, 1torr or less, the S content was 0.2wt% or less and the commercial S content (<0.1wt% S). From the reaction temperature of 1400 ℃, 0.1torr or less showed the same or less than the commercial S content.

Example  4

In order to change the Fe content, 1g of Fe powder was added, and when the amount of C was added in an excess of 1.5wt%, the behavior of impurities in precipitated Fe-Mo is shown in Table 2.

Figure 7 shows the content of impurities as the degree of vacuum changes at 1350 ℃, Figure 8 shows the content of impurities as the degree of vacuum changes at 1400 ℃.

As shown in Table 4 and FIGS. 7 and 8, when Fe powder was added, the amount of C was added in an amount of 1.5wt at a reaction temperature of 1350 ° C. and 1400 ° C. and the reaction time was 6hr. As the vacuum degree changed from 100torr to 0.01torr, Unlike in Table 1, the impurity content was drastically decreased as the vacuum degree was changed even at 1350 ° C., and it was similar to the commercially available S content at 0.01torr. In addition, when 1torr or less at 1400 ℃, the content of S was less than 0.1wt%, which was close to the commercial content of S. Therefore, lowering the degree of vacuum and increasing the Fe content, it can be seen that it is possible to produce Fe-Mo even at low vacuum.

Example  5

In Example 5, the reaction time was reduced from 6hr to 3hr in order to lower the manufacturing cost, and the results of ICP analysis on Fe-Mo precipitated after reduction under the same conditions are shown in Table 5.

Figure 9 shows the content of impurities as the degree of vacuum changes at 1350 ℃, Figure 10 shows the content of impurities as the degree of vacuum changes even at 1400 ℃.

As shown in Table 5 and FIGS. 9 and 10, the content of S was 0.26 wt% at the reaction temperature of 1350 ° C., the degree of vacuum, and 0.01 torr, and 0.17 wt% at 1400 ° C., similar to the commercial S content. . Therefore, considering the reaction time, vacuum degree, reaction temperature, etc. at the most economical conditions, Fe-Mo production by process simplification is considered possible.

Figure 9 shows the content of impurities as the degree of vacuum changes at 1350 ℃, Figure 10 shows the content of impurities as the degree of vacuum changes even at 1400 ℃.

Example  6

In Example 6, experiments were carried out by mixing and loading MoS2, Fe powder (Iron powder), and other fillers and binders as raw materials without loading Fe2O3 and C as a reducing agent among the additives participating in the reaction when manufacturing Fe-Mo by the process simplification. Was carried out.

Looking at the reaction mechanism in the present invention, MoS2 is pyrolyzed at 1400 ℃ or more, the decomposed S2 is evacuated to a gaseous state and Mo and Fe reacted to form Fe-Mo was carried out this experiment. Scheme is the same as in Scheme 2.

MoS2 + Fe + binder + filler → FeMo + S2 ↑ + M (Scheme 2)

The experimental method is the same as the above method, and look at the content of impurities in the recovered Fe-Mo after the reaction as shown in Table 6.

11 shows the content of impurities as the amount of Fe powder added at 1400 ° C. changes.

As can be seen from Example 6, there was a slight difference according to the Fe content change, but it was found that more than 5% of SiO 2 was incorporated as an impurity, and it was necessary to identify the role of Fe 2 O 3 and C in the above reaction. Example 7 was carried out.

Example  7

In Example 6, pellets are prepared and mixed by mixing elements necessary for manufacturing Fe-Mo without loading Fe2O3, that is, raw material MoS2, Fe powder for Fe content control, binder, filler, and the like. As a result of the experiment, the reduction reaction was performed smoothly, but more than 5% of SiO2 content was detected in all samples. In other words, it was found that SiO 2 contained in the raw material remained in the sample without reacting at all. As a result, SiO 2 reacted with FeO and CaO to be separated into the pellet surface during slag reaction.

Table 7 shows the results of the ICP analysis of the sample after Fe2O3 mixed charging.

12 shows the content of impurities as the amount of Fe powder added at 1400 ° C. is changed.

As shown in FIG. 12 and Table 7, when Fe2O3 was mixed and loaded, SiO2 and other impurities were hardly detected, and most of them were reacted with two-component slag of FeO-SiO2 to be separated and removed from the sample.

In addition, as a method for producing ferro-molybdenum by the process step according to the present invention, the reduction reaction at high temperature and low vacuum resulted in good decomposition of MoS2, it was found that S is exhausted and pure Fe-Mo can be produced.

As shown in Table 8, the content of Mo, Fe and other impurities in the production of Fe-Mo by the ferro molybdenum manufacturing method by the process singularization according to the present invention is manufactured by SeAH M & S, the only company in Korea. Comparing the Fe-Mo with the main content, it was found to be consistent with or less than the main content in Fe-Mo.

While the invention has been shown and described in connection with specific embodiments thereof, it is conventional in the art that various changes, modifications and variations are possible without departing from the spirit and scope of the invention as indicated by the appended claims. Anyone who knows the knowledge of is easy to know.

S100: pellet manufacturing step
S200: first reduction step
S300: second reduction step

Claims (7)

A pellet manufacturing step of mixing molybdenite (MoS ₂ ), iron powder (Fe powder), hematite (Fe ₂ O ₃ ), carbon as a reducing agent (C), a binder, and a filler to produce pellets;
A first reduction step of performing a thermal reduction reaction on the pellets prepared through the pellet manufacturing step at a reduced pressure of 10 ⁻² torr to 1 torr and a temperature of 1350 ° C. to 1400 ° C .; And
In order to remove sulfur (S) from the pellet, a ferro molybdenum production process by the step-reduction step comprising a second reduction step of blowing and exhausting hydrogen gas (H2) at 298 ℃ to 300 ℃ for 3 hours. . delete The method of claim 1,
The binder is gelatin (Gelatines), starch (Sugars), molasses (Molarsses), Na2SiO3 characterized in that any one or more of the ferro molybdenum manufacturing method by the singularity. The method of claim 1,
The filler is a ferro molybdenum manufacturing method by a single stage, characterized in that any one or more of wood flour, fiber (fiber), particles (particles). delete delete delete

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