KR20100076116A - Apparatus for dephosphorization of ferromanganese and a method for dephosphorization of ferromanganese - Google Patents

Abstract

PURPOSE: An apparatus for dephosphorization of ferromanganese and a method for dephosphorization of ferromanganese are provided to reduce processing time by a mixing effect due to the rotation of a rotor and a pulverized body dispersing effect. CONSTITUTION: An apparatus for dephosphorization of ferromanganese and comprises a rotor shaft, multiple agitating blades(20), a pulverized body blow pipe(30), and a drive motor. The rotor shaft is formed in the height direction. Multiple agitating blades are formed on the outer surface of the rotor shaft. The pulverized body blow pipe is formed inside the agitating blade. The pulverized body blow pipe has the pulverized body. The drive motor rotates the rotor shaft.

Description

Apparatus for Dephosphorization of Ferromanganese and a Method for Dephosphorization of Ferromanganese}

The present invention relates to a ferromangan dephosphorization apparatus and a dephosphorization method, and more particularly, to a ferromangan dephosphorization apparatus and a dephosphorization method capable of reducing phosphorus content by a mechanical stirring method using a rotor having a powder blowing pipe therein.

Ferro-manganese used as steel for ferroalloy is classified into high carbon when the carbon content is 7.5% or less, heavy coal when the carbon content is less than 7.5%, and low carbon when the carbon content is less than 1.0% according to the KS standard KSD3712 standard.

The process for producing ferro-manganese is prepared by charging manganese ore and reducing agent coke and slag forming agent into the electric furnace to reduce the manganese ore in the form of oxide using carbon of the coke. Thus, the ferromanganese produced by using coke in the electric furnace is obtained in the form of high-carbon ferro-manganese in which carbon is saturated in the product due to coke as a reducing agent.

The method for manufacturing the medium / low carbon ferro-manganese is a method for producing low-carbon ferro-manganese by melting and reducing Mn ore in an electric furnace using SiMn, US Patent (US3305352, US5462579), Japanese Patent (S61 61-276920, S61) -276921, Small 62-206762, JP3870546), Korean Patent (1994-0014385), etc., a method of producing low-carbon ferro-manganese by blowing oxygen into the molten high-carbon ferro-manganese and decarburizing.

Phosphorus (P) content of commonly used ferro manganese has been shown to be high, mostly 0.4% or less, and phosphorus (P) content of ferro manganese, which is frequently used for steelmaking, is relatively high as 0.1 to 0.2%.

Problems in using commonly used ferro manganese in the steelmaking process can be divided into carbon and phosphorus (P). In the case of carbon, high-carbon ferro-manganese or medium / low-carbon ferro-manganese can be selectively used depending on the carbon content of the steel produced. However, phosphorus (P) contains high levels of high-carbon, bi-carbon and low-carbon ferro-manganese, so that the type of ferroalloy Even if it changes, there is no way to avoid the influence of phosphorus (P) contained in ferromanganese. In general, phosphorus (P) is present as an impurity in the steel, and since it impairs the quality of steel products such as causing high temperature brittleness, except for special cases, efforts are made to lower the content of phosphorus (P) in molten steel. Therefore, in the case of using ferro-manganese ferroalloy, an increase in phosphorus (P) concentration in molten steel by the ferroalloy should be taken into account, and thus, ferro-manganese cannot be used.

In order to solve such a problem, it is necessary to manufacture low-ferrofermanganese containing less phosphorus (P). In order to manufacture the low ferro-manganese is used a method of beneficiation only by manganese ore having a low content of phosphorus (P).

In general, low phosphorus (P) ores are known to exhibit poor operability in an electric furnace reduction process, and the price of high-grade ores is increasing due to a decrease in reserves of high-quality manganese ores used for ferro-manganese. On the other hand, as the amount of low-grade ore is increased in the ferro-manganese manufacturing process, there is a problem in that the content of phosphorus in the ferro-manganese increases. Therefore, in some overseas research journals, a method of producing ferromangan after lowering the content of phosphorus in ore by roasting or leaching phosphorus in ore in order to use low-grade ore with high phosphorus (P) is known. It is used.

Another method of preparing low-carbon ferro-manganese is a method of producing low-carbon low-ferro-manganese by reducing non-carbon-based reducing agents (Si, Al, Ca, etc.) from slag or low phosphorus content generated in high-carbon ferro-manganese manufacturing process. (US 4,282,032, US 4,363,657) and Japanese Patent (JP2006-161079).

In general, slag produced during the production of high-carbon ferro-manganese is reduced by the phosphorus in the ore in the electric furnace in the form of manganese oxide with little phosphorus content, so it is reduced to a non-carbon-based reducing agent to reduce the content of phosphorus in iron alloy I can make it. However, such a method has to produce a general ferro-manganese having a high content of phosphorus by using by-products generated in the manganese ferroalloy manufacturing process, there is a problem that can not be produced in large quantities.

In order to solve this problem, a method of manufacturing low-ferro-manganese by directly dephosphorization in high-carbon ferro-manganese produced in an electric furnace has been proposed in US patents (US 4662937, US 4684403, US 4752327) and various research papers. The method for preparing low ferro-manganese can be roughly divided into tallin oxide and reduced tallin.

Reduction Tallinn phosphide phosphorus (P) of ferro manganese _{(Ca 3 P 2, Mg 3} P 2 , etc.) is a method of removing in the form of oxide, Tallinn cargo phosphate phosphorus (P) of ferro manganese (Ba ₃ ( PO ₄ ) _2, etc.). In the case of reduced Tallinn, Ca or Mg is mainly used. In the case of reduced tallin, the tallin efficiency is high, but in the case of Ca, delineation is impossible in high-carbon ferro-manganese due to the formation of carbides. In addition, the Tallinn products Ca ₃ P ₂ , Mg ₃ P ₂ react with water to produce toxic gas, phosphine.

In case of deoxidation, BaCO ₃ , BaO, BaF ₂ , BaCl ₂ , CaO, CaF ₂ , Na ₂ CO ₃ , Li ₂ CO ₃ and the like are used. Among them, the Ca-based material has low thallin efficiency, and Na and Li-based have high vapor pressure, thus causing a fugitive phenomenon. Therefore, BaCO ₃ and BaO are mainly used. Among them, BaO does not have an oxygen source for oxidizing phosphorus (P), so an oxidant is used together.

In the case of using BaCO ₃ or BaO, since slag generated is generated in a solid phase and dephosphorization efficiency is lowered, BaCl ₂ or BaF ₂ is used to solve the problem. In case of using BaCl ₂ , slag on the upper part of ferro-manganese is scattered due to equipment pollution and vaporization of Cl group due to the highly corrosive Cl group. There is a problem that it is difficult to establish an economic production process.

In order to solve the problems as described above, by using a mechanical stirring method using a rotor, there is provided a ferro-manganese dephosphorization apparatus and a delineation method that can produce molten ferro-manganese with a low by-product, low phosphorus content.

Ferromanganese dephosphorization apparatus according to the present invention for achieving the above object,

A rotor shaft formed in a height direction; A plurality of stirring vanes radially formed on an outer surface of the rotor shaft; A powder blowing tube formed inside the rotor shaft and the stirring blade and blowing powder and powder conveying gas; And a drive motor connected to rotationally drive the rotor shaft.

The rotor shaft and the stirring blades are thermally stable at 1300 to 1400 ° C., and are made of a chemically stable refractory material in contact with high basic slag. At this time, the refractory is preferably made of any one of magnesium oxide (MgO), carbon (C) and a mixture thereof.

The rotational trajectory formed by the stirring vane is larger than 1/10 of the inner diameter of the ladle and less than 2/3, and the thickness of the stirring vane is preferably larger than 1/4 and smaller than 1 of the wing height.

The powder blowing pipe is branched into two or more sub powder blowing pipes inside the rotor shaft, and the sub powder blowing pipe is bent in the stirring blade direction.

It is preferable that the cross-sectional area of the powder blowing pipe and the sum of the cross-sectional areas of the sub powder blowing pipes are the same.

The sub powder blowing tubes are branched at an angle of 5 ° or less with the central axis of the powder blowing tube at a branched point, and the curvature of the sub powder blowing tubes is 20 times or more of the diameter thereof.

It is preferable that the nozzle tip direction of the said sub powder blowing pipe is a direction opposite to the rotation direction of the said stirring blade.

In addition, the ferro manganese delineation method according to the present invention, the step of reducing the ferro manganese using carbon as a reducing agent; Blowing the high basic flux powder using the powder transfer gas, and mechanically stirring the blown high basic flux powder with the reduced ferromangan; And removing carbon by adding oxygen to the dephosphorized ferromanganese. In this case, the powder transport gas is preferably an inert gas or an oxidizing gas.

According to the present invention as described above, by producing a ferro-manganese was stirred by mechanical stirring using a rotor having a powder blowing tube, the mixing effect by the rotation of the rotor and the powder dispersion effect by the powder blowing by the powder blowing tube reaction surface area In this way, the treatment time is significantly shortened compared to the gas stirring method. In addition, since the mechanical stirring is performed, there is an effect that can be easily prevented by the generation of by-products.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; First, it should be noted that the same components or parts in the drawings represent the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the gist of the present invention.

The present invention relates to a ferromangan dephosphorization apparatus which deposits and rotates a rotor in molten ferro-manganese and blows high-basicity flux powder through a powder blowing tube to remove slag of phosphorus contained in molten ferro-manganese with slag.

To this end, the ferro-manganese dephosphorization apparatus according to an embodiment of the present invention, as shown in Figure 1, to rotate the rotor shaft 10, the stirring blades 20, the powder blowing pipe 30, and the rotor shaft And a drive motor (not shown) connected to each other. The powder blowing pipe may be branched into at least two sub powder blowing pipes 31.

The rotor shaft 10 is formed in the height direction, two or more stirring blades 20 are formed radially on the outer surface of the rotor shaft. Since the rotor shaft 10 and the stirring blades 20 are deposited and rotated in the molten ferro-manganese, the rotor shaft 10 and the stirring blade 20 are preferably thermally stable at a melting temperature range of 1300 to 1400 ° C. between the molten ferro-manganese and chemically in contact with the high basic slag. It is preferable that it consists of stable refractory materials. As the refractory material, any one of magnesium oxide (MgO), carbon (C), and a mixture thereof may be used, and other materials may be used according to contact areas.

Rotational trajectory (a) formed by the stirring blade 20 is preferably larger than 1/10 and less than 2/3 of the inner diameter of the ladle in which the molten ferro-manganese is accommodated. In addition, the height (b) of the stirring blade is preferably larger than 1/10 of the depth to which the molten ferro-manganese submerged. In addition, the stirring blade thickness (c) is preferably larger than 1/4 and less than 1/1 of the wing height.

If the rotational trajectory (a) and the height (b) of the stirring blade are smaller than the lower limit defined above, the rotational force applied to the molten ferro-manganese is small, so that sufficient mixing effect cannot be expected, and if the upper limit is larger, the volume occupied by the rotor is too large to be deposited. Freeboard and buoyancy are difficult. In addition, if the thickness (c) of the stirring blade is smaller than the lower limit defined above, the service life is significantly reduced due to abrasion loss, and if larger than the upper limit, the volume occupied by the rotor is so large that it is difficult to secure the freeboard and support buoyancy during deposition.

The powder blowing pipe 30 formed inside the rotor shaft 10 and the stirring blade 20 should be smoothly transported with the transfer gas without clogging. Therefore, the inner wall of the powder injection pipe 30 should have a constant diameter and no step.

The powder blowing pipe 30 is branched into two or more sub powder blowing pipes 31 in the rotor shaft, and the sub powder blowing pipe is bent in the stirring blade direction. At this time, it is not necessary for the sub powder blowing pipe to branch to the stirring blade in the same number. The sum of the cross-sectional area of the powder blowing pipe and the cross-sectional area of the sub powder blowing pipe should be kept constant, preferably the same cross-sectional area. In addition, the sub powder blowing pipes 31 are branched at an angle of 5 ° or less with the central axis of the powder blowing pipe 30 at a branched point, and the curvature of the sub powder blowing pipes is 20 times or more of the diameter thereof. It is preferable. If the sum of the cross-sectional area of the powder blowing pipe before branching and the sum of the cross-sectional areas of the sub powder blowing pipes after branching are not constant, pressure difference and nozzle clogging occur in the conveying gas, and the angle of the branched point exceeds 5 ^o or after branching This is because when the curvature is 20 times or less of the inner diameter of the sub powder blowing pipe, clogging due to pressure loss occurs.

In addition, since the gas, which is a compressive fluid, is used as a transfer medium, when the nozzle tip 32 of the powder blowing pipe is formed in the same direction as the rotation direction of the stirring blade, a back pressure is formed to block the inlet of the nozzle tip. Frequently, Therefore, it is preferable that the direction of the tip end 32 of the said sub powder blowing pipe 31 which contacts molten ferro manganese is a direction opposite to the rotation direction of the said stirring blade 20. As shown in FIG. When the direction (d) of the tip of the nozzle is opposite to the direction of rotation (R) of the stirring blade, the back pressure, which is a characteristic of the compressible gas, is minimized, thereby minimizing nozzle clogging due to the back pressure. The powder transfer gas may promote the oxidation reaction of phosphorus by using an inert gas or an oxidizing gas capable of maintaining a constant oxygen partial pressure.

Next, with reference to Figure 2 will be described a ferromanganese Tallinn method according to the present invention.

First, the ferro manganese is reduced by using carbon as a reducing agent (S10). That is, carbon is added as a reducing agent to a reduction electric furnace containing ferro-manganese ore, and reacted to remove oxygen components contained in the ferro-manganese ore.

Then, after immersing the reduced ferromangan in the label on the label, the high basic flux flux powder is blown into the label using a powder transport gas, and the high basic flux flux powder and the reduced ferro manganese are mechanically injected. Stirring by stirring. (S20)

At this time, the mechanical agitation between the flux of the high basic flux powder and the ferromangan may be performed, for example, through the ferromangan dephosphorization apparatus in which the above-described powder blowing tube is formed. That is, the reduced ferromangan can be mechanically agitated by blowing the flux powder of high basicity using the powder conveying gas through the powder injection pipe formed in the apparatus, and rotating the stirring blade. It is preferable that the said powder conveyance gas is an inert gas or an oxidizing gas. In this process, phosphorus contained in ferromangan is removed. Although there are some differences in the dephosphorization rate depending on the number of revolutions per minute stirring blades described later, the dephosphorization method using the mechanical stirring method of the present invention shows a dephosphorization rate of approximately 45 to 50%, which is a gas using a conventional gas. The effect is superior to 20 to 35% of the delineation rate of the stirring method.

Then, oxygen is added to the dephosphorized manganese to remove carbon (S30). That is, when oxygen is added and reacted, carbon contained in the manganese is generally generated and removed in the form of CO ₂ .

In the ferromanganese Tallinn method of the present invention, the steps S10 and S30 are known stages and can be easily performed by those skilled in the art without special description. S20 step is to use the mechanical stirring method instead of the conventional gas stirring method in the present invention, in particular can be carried out more effectively by using the ferromangan dephosphorization apparatus according to the present invention.

Next, with reference to Figures 3 and 4 looks at the effect of the delineation process when using the ferromangan delineation apparatus according to an embodiment of the present invention.

3 is a graph showing a change in the concentration of phosphorus contained in the molten ferro manganese with time when the dephosphorization process using the ferro manganese dephosphorization apparatus according to an embodiment of the present invention. The rotor used in FIG. 3 is a delineation process by mechanical stirring using a rotor having a rotation rate per minute (RPM) of 100.

Referring to FIG. 3, it can be seen that molten ferro-manganese having an initial phosphorus concentration of about 0.1% by weight is rapidly dephosphorized immediately after the start of the process, and represents about 0.05% by weight after about 7 minutes has elapsed.

Figure 4 is a graph showing a comparison of the delineation rate of the delineation process of the delineation process using a ferromangan dephosphorization apparatus according to an embodiment of the present invention and the delineation process using gas stirring. The graph labeled 'Top' is a top gas agitation method, and the graph labeled 'Bottom' is a delineation process using a bottom gas agitation method. The gas used is an inert gas (room temperature, 1 atm). The graphs shown as 'KR-R1', 'KR-R2', 'KR-R3', and 'KR-R4' indicate that the ferromanganese Tallinn apparatus of the present invention is set at 250, 150, 100, and 50 revolutions per minute (RPM), respectively. The delineation process was performed by mechanical stirring.

Referring to FIG. 4, while the mechanical agitation showed a delinquency rate of 45 to 50%, in the gas agitation method, the delinquency rate was only 20 to 35%. Therefore, it can be seen that the delineation process using the mechanical stirring method using the ferromangan delineation apparatus according to an embodiment of the present invention is more effective.

As described above with reference to the drawings illustrating a ferro-manganese dephosphorization apparatus and a delineation method according to an embodiment of the present invention, the present invention is not limited by the embodiments and drawings disclosed herein, of the present invention Of course, various modifications may be made by those skilled in the art within the scope of the technical idea.

1 is a perspective view showing a ferro-manganese Tallinn device according to an embodiment of the present invention,

2 is a flowchart illustrating a ferromanganese Tallinn method according to an embodiment of the present invention,

3 is a graph showing a change in the concentration of phosphorus contained in molten ferro-manganese with time during the delineation process using a ferromangan dephosphorization apparatus according to an embodiment of the present invention,

Figure 4 is a graph showing a comparison of the delineation rate of the delineation process of the delineation process using a ferromangan dephosphorization apparatus according to an embodiment of the present invention and the delineation process using gas stirring.

<Description of the symbols for the main parts of the drawings>

10: rotor shaft 20: stirring blade

30: powder blowing pipe 31: sub powder blowing pipe

32: nozzle tip a: rotational trajectory of the rotor

b: height of rotor blade c: thickness of rotor blade

d: nozzle tip direction for powder injection R: rotation direction of rotor

Claims (10)

A rotor shaft formed in a height direction; A plurality of stirring vanes radially formed on an outer surface of the rotor shaft; A powder blowing tube which is formed inside the rotor shaft and the stirring blade and blows powder; And, A drive motor connected to rotationally drive the rotor shaft Ferromangan Tallinn device comprising a. The method according to claim 1, The rotor shaft and the stirring blade is thermally stable at 1300 to 1400 ℃, ferromangan dephosphorization device made of a refractory chemically stable even in contact with high basic slag. The method according to claim 2, The refractory is a ferro manganese dephosphorization device made of any one of a material of magnesium oxide (MgO), carbon (C) and mixtures thereof. The method according to claim 1, The rotational trajectory formed by the stirring vane is greater than 1/10 of the inner diameter of the ladle and less than 2/3, the thickness of the stirring vane is greater than 1/4 of the height of the blade and less than 1 ferromangan Tallinn apparatus. The method according to claim 1, And the powder blowing pipe is branched into two or more sub powder blowing pipes in the rotor shaft, and the sub powder blowing pipe is bent in the stirring blade direction. The method according to claim 5, The cross-sectional area of the powder blowing pipe and the sum of the cross-sectional areas of the sub powder blowing pipes are the same. The method according to claim 5, And the sub powder blowing tubes branch at an angle of 5 ° or less with the central axis of the powder blowing tube at a branched point, and the curvature of the sub powder blowing tubes is 20 times or more of their diameter. The method according to claim 5, The nozzle tip direction of the said sub powder blowing pipe | tube is the ferromangan dephosphorization apparatus which is a direction opposite to the rotation direction of the said stirring blade. Reducing ferromanganese using carbon as a reducing agent; Blowing the high basic flux powder using the powder transfer gas, and mechanically stirring the blown high basic flux powder with the reduced ferromangan; And, Removing carbon by adding oxygen to the dephosphorized ferro-manganese Ferromangan Tallinn method comprising a. The method according to claim 9, The powder delivery gas is an inert gas or oxidizing gas ferromangan dephosphorization method.

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