JPH0448024A - Vacuum suction type degassing device - Google Patents

Abstract

PURPOSE:To sufficiently remove the gaseous components in a melt with a small amt. of gaseous Ar by placing the surface of the melt housed in a housing vessel under a reduced pressure state, blowing an inert gas into the melt to discharge the degassing components in the melt into a reduced pressure atmosphere and placing the inside of a partition member which is formed of a porous material to allow the diffusion of gases but does not allow the infiltration of the melt and is immersed in the melt under a vacuum. CONSTITUTION:The reduced pressure atmosphere is maintained in the reduced pressure vessel 2 by a vacuum suction pump and the gaseous Ar or the like is supplied into a bubble generator 9 to generate bubbles in the melt 2. The degassing member 6 is internally sucked via a piping 8a by the vacuum pump to maintain a vacuum or reduced pressure state in the degassing member 6. The degassing components in the melt 2 are discharged together with the bubbles of the inert gas into the reduced pressure atmosphere in the reduced pressure vessel 10 and are discharged through the partition member 6a of the degassing member 6 into the degassing member 6. These components are removed via the piping 8a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is a method for removing solute components that generate a gas phase from a melt such as a molten metal, a molten matte, and a molten slag through a porous member. This invention relates to a vacuum suction type degassing device for recovery.

[Prior Art] Conventionally, there are degassing methods such as the RH method and the DH method as technologies for removing or recovering solute components that generate a gas phase from melts such as molten metal, molten matte, and molten slag. . In the RH method and the DH method, a large amount of argon gas is blown into the molten metal under vacuum or reduced pressure to lower the partial pressure of the gas component in the molten metal and remove this gas component.

[Problems to be Solved by the Invention] However, the conventional degassing methods using the RH method and the DH method use a large amount of argon gas, and therefore have a drawback of high running costs.

Another drawback is that the concentration of gas-forming components in the melt after degassing is not sufficiently reduced.

The present invention has been made in view of such problems, and includes:
Gas components in the melt can be easily removed without using large amounts of argon gas, running costs are low, and the concentration of gas-generating components in the melt can be reduced compared to conventional methods. The purpose of the present invention is to provide a vacuum suction type degassing device.

[Means for Solving the Problems] A vacuum suction type degassing apparatus according to the present invention includes: a storage container containing a molten material; a depressurizing means for placing the molten material in the storage container under reduced pressure; an inert gas blowing means for blowing an inert gas into the molten material in the storage container; and a porous material formed of a porous material that permeates gas but not the molten material and is immersed in the molten material in the storage container. A partition member of a bottomed cylindrical cane, and a suction means for sucking gas in the melt or gas generated by a reaction between the melt and the components of the partition member while the inside of the partition member is under vacuum or reduced pressure. It is characterized by having the following.

[Operation] In the present invention, the depressurization means places the scene of the molten material in the storage container under reduced pressure. This is carried out, for example, by placing a storage container containing the melt in a reduced pressure container and creating a vacuum or a reduced pressure atmosphere in the reduced pressure container. Further, at the same time as the pressure is reduced in this scene, an inert gas is blown into the molten material in the storage container by an inert gas blowing means. Then, the gas-generating components in the melt are gasified and ejected from the melt scene, for example, into the atmosphere in a vacuum vessel, together with inert gas bubbles. Further, in the present invention, a partition member formed into a bottomed cylinder made of a porous material that allows gas to pass through the melt but does not allow the melt to pass through is immersed. The inside of this partition member is vacuumed or under reduced pressure by the suction means. As a result, the gas-generating components in the melt pass through the partition member and are discharged into the partition member.

In this way, in the present invention, the gas generating components are discharged into the vacuum or reduced pressure atmosphere in which the melt is placed, and are also removed from the melt through the partition member immersed in the melt. Ru. Therefore, the degassing treatment of the melt can be performed with high efficiency.

FIG. 3 is a schematic diagram showing the principle of separation of gas generating components using a porous member. The partition member 1 is a member made of a porous material that allows only gas to pass therethrough and does not allow melts such as molten metal, molten matte, and molten slag to pass therethrough. When the molten material 2 is brought into contact with one surface of the partition member 1 and the other surface is placed in a vacuum or reduced pressure atmosphere 3, the wall surface in contact with the molten material 2 is independent of the static pressure of the molten material 2. Pressure decreases.

Therefore, impurity components in the melt 2 or valuable components worth recovering that generate a gas phase easily nucleate on the wall surface of the partition member 1, and the generated gas 4 is transferred to the partition member 1. It is separated from the melt 2 by passing through.

The inventors of the present invention have come up with the idea that gas components can be removed from a molten material based on such a principle, and have completed the present invention.

Thus, the gas-generating components dissolved in the melt are removed in the form of gas according to the reaction formula below.

Roof +, N-→Nt...(1) Upward+1L-H2... (2) ℃+Ω-→CO...(3) 1+2Ω-→SO3...(4) Also, during melting After the impurities react with the porous material component of the partition member to become a gas, the impurities may permeate through the partition member and be removed.

When the porous material is an oxide (MXOY), carbon in the melt is removed as a gas according to the reaction formula below.

YfL+Mx O+' (solid) -+x[+yCO・
(5) In addition, when the porous material is composed of carbon or contains carbon as one component, oxygen in the melt is removed according to the following reaction formula.

U+C (solid)→CO (6) Furthermore, the valuable component (M) having a high vapor pressure in the melt is separated and recovered by gasifying the valuable component according to the following reaction formula.

xM → M, (gas) ... (7) M
Ov → Mow (gas) ... (8) MS,
→MSY (gas) (9) In this way, impurity components and valuable components such as N, H, C, O, and S in the melt are removed or recovered from the melt.

In this case, in the present invention, the concentration of the component in the partition member that reacts with the impurities or valuable components in the target melt is adjusted according to the impurities or valuable components in the melt. It is also possible to control the rate of reaction between impurities or valuable components and components in the partition member.

In addition, the temperature of the molten material decreases due to heat radiation to the atmosphere and the storage container, the temperature of the molten material decreases due to immersion of the partition member in the molten material, and the temperature of the molten material due to an endothermic reaction between the components of the partition member and the molten material. In order to avoid the occurrence of inconveniences caused by a decrease in the temperature, it is necessary to energize the partition member, bury a resistance wire in the partition member in advance and energize the resistance wire, or use external heating (
For example, a heating means capable of heating the partition member and the melt by a method such as plasma heating may be provided.

Porous materials include At20+, MgO1CaO1
Sio. , Fent O*, Fea 04, Cr2
Various materials can be used, such as 0z, BNlS i3N, metal oxides such as SiC and C, metal non-oxides and carbon, and mixtures thereof, but those that do not react with the main component of the melt are preferred. In this manner, by not reacting with the main component, the partition member that comes into contact with the melt is prevented from being melted and damaged.

Furthermore, in order to allow only the gas to pass through and not the molten material, a partition member made of a porous material that is difficult to get wet with the molten material is used. Furthermore, the porosity of the partition member is preferably 40% or less. Furthermore, although it varies depending on the wettability of the partition member to the melt, the pore diameter of the partition member is about 20
The thickness is preferably 0 μm or less.

Furthermore, in order to prevent molten material from entering the vacuum system even if it enters the porous immersion tube, a filter with low pressure loss is installed at the top of the porous immersion tube to prevent the molten material from entering the porous immersion tube. It is preferable to coagulate and trap it in a filter.

Next, an application example in which the present invention is applied to the removal and recovery of gas generating components from a melt will be described.

(1) First, the present invention can be used in decarbonization, denitrification, and dehydrogenation processes for removing carbon, nitrogen, or hydrogen from molten iron.

When illegally removing carbon from molten iron, the main component of the partition member is Al2O2 or MgO, and Fe 203 +Fe304 + is used as the main oxidizing agent for carbon in molten iron.
Blend MnO, S i 02, etc. By increasing the blending ratio of these main oxidizing agents, the rate of oxygen removal from molten iron can be increased. However, if the blending ratio of the main oxidizing agent is too high, it will lower the melting point or mechanical strength of the partition member, and especially if the carbon concentration in the molten iron is low, the oxygen concentration in the molten iron will increase. ,
Depending on the purpose, the blending ratio of the main oxidizing agent is determined with reference to the already established phase diagram.

On the other hand, if illegal methods are used to remove nitrogen from molten iron, the partition member may contain stable oxides such as CaO*A.
120 a + M g O etc. are used.

Furthermore, when using an illegal method to simultaneously remove carbon and nitrogen from molten iron, the blending ratio of the main oxidizer is changed depending on the target concentration of carbon and nitrogen in molten iron.

(2) The present invention can also be applied to a deoxidation process for removing oxygen from molten steel.

(2) Furthermore, the present invention can also be applied to a dehydrogenation process for removing hydrogen from molten aluminum.

(2) Furthermore, the present invention can be applied to decarbonization, denitrification, and dehydrogenation of molten silicon.

(2) On the other hand, according to the present invention, zinc in the melting vessel can be recovered.

(2) The present invention can also be applied to the deoxidation process in a desulfurization chamber to remove sulfur and oxygen from molten copper matte.

(2) Valuable metals (As, Sb+Bt, Se, Te) in the molten steel matte or nickel matte.

The present invention can also be applied to the recovery of Pb, Cd, etc.).

■ Furthermore, valuable metals (A s + S
b + B s + S e + T e + P b
, Cd + Z n, etc.).

[Embodiments] Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view showing a first embodiment of the present invention.

The molten material 2 is stored in a storage container 5, and this storage container 5
is placed inside the vacuum container 10. A bubble generator 9 made of bottom-blown porous brick is provided at the bottom of the storage container 5, and a bubble generator 9 is connected to A via a pipe 8b.
Inert gas such as r gas is supplied.

Further, the reduced pressure container 10 is connected to a vacuum suction pump (not shown), so that a reduced pressure atmosphere can be created inside the reduced pressure container 10.

The lower half of the degassing member 6 is immersed in the melt 2 . This degassing member 6 has a cylindrical shape with a closed lower end, and the molten material 2
The lower half that is immersed in the interior has pores that allow gas to pass through but prevent molten material 2 such as molten metal, molten slag, and molten matte from penetrating. Molded from quality materials. A portion formed of a porous material in the lower half of this degassing member 6 is a partition member 6a.

Further, the upper half of the degassing member 6 is formed of a dense member 6b that does not allow gas to pass through. This partition member 6a
The degassing member 6b and the dense member 6b may be created separately and then joined together to integrate them, or the degassing member 6b may be made of a porous material.
After creating the entire dense member 6b, this portion may be made gas-impermeable by coating the portion with a gas-impermeable dense material.

A gas-impermeable dense member 6 exposed above the melt 2
A connecting member 7 is fixed to the upper end of b, and a pipe 8a connected to a suitable vacuum pump (not shown) is connected to this connecting member 7 so as to communicate with the degassing member 6. ing.

In the vacuum suction type degassing apparatus configured in this way, the vacuum suction pump creates a reduced pressure atmosphere in the reduced pressure volume Ws 10, and Ar gas or the like is supplied to the bubble generator 9 to generate air bubbles in the melt 2. to occur.

Further, the inside of the degassing member 6 is sucked through the piping 8a by a vacuum pump, and the inside of the degassing member 6 is brought into a vacuum or reduced pressure state.

As a result, the degassed components in the melt 2 are discharged together with the inert gas bubbles into the reduced pressure atmosphere in the decompression container 10, and are also transmitted through the partition member 6a of the degassing member 6 into the interior of the degassing member 6. and is removed via piping 8a.

In this way, in the apparatus of this embodiment, the degassed components in the melt 2 are discharged into the reduced pressure atmosphere in the reduced pressure container 10, and are also removed from the melt 2 through the partition member 6a made of a porous material. Therefore, the degassing process speed of the melt 2 is high, and the concentration of the degassed components in the melt can be made extremely low.

Moreover, since the inert gas only needs to be supplied in a small amount to the extent that the melt 2 is stirred, running costs are low.

FIG. 2 is a schematic cross-sectional view showing a second embodiment of the present invention.

This embodiment differs from the first embodiment in that the shape of the degassing member is different, and the other configurations are basically the same as the first embodiment. Components that are the same as those shown in FIG.

The degassing member 12 includes a plurality of (three in the figure) bottomed cylindrical partition members 12a made of a porous material and a housing 12b connected to these partition members 12a. This degassing member 12 is connected to a vacuum pump (not shown), and the inside is sucked into a vacuum or reduced pressure state by this vacuum pump.

In this embodiment, the partition member 1 made of porous material
Since the contact area between 2a and the melt 2 is large, this embodiment has the advantage that the removal efficiency of gas generating components from the melt 2 is higher than in the first embodiment.

[Effects of the Invention] As explained above, according to the present invention, the surface of the molten material stored in the storage container is placed under reduced pressure, and the inert gas is blown into the molten material by the inert gas blowing means. The degassing components in the body are discharged into the reduced pressure atmosphere, and a partition member formed into a bottomed cylindrical shape made of a porous material that allows gas to pass through but not the melt is immersed in the melt, and the partition member is immersed in the melt. Since the interior of the member is vacuumed or under reduced pressure to suck up the gas generated by the reaction between the melt and the porous material, the gas-generating components in the melt can be separated with extremely high efficiency; The concentration of solute components in the melt can be reduced to extremely low concentrations.

Unlike the conventional degassing method in which a large amount of argon gas is blown into the melt, the present invention only needs to supply a small amount of argon gas to the extent that the melt is stirred, and running costs can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of the device of the present invention, FIG. 2 is a schematic sectional view of a second embodiment of the device of the present invention, and FIG. 3 is a schematic sectional view of a device using a porous material. FIG. 2 is a schematic diagram showing the principle of degassing. 1.6a, 12a; partition member, 2; melt, 3; vacuum or reduced pressure atmosphere, 4; gas, 5; storage container, 6.12; degassing member, 6b, 12b; dense member, 7; connecting member ,
8a, 8b; Piping, 9; Bubble generator, 10; Decompression container

Claims (2)

[Claims] (1) A storage container containing a molten material, a pressure reducing means for reducing the surface of the molten material in the storage container, and an inert gas for blowing an inert gas into the molten material in the storage container. a blowing means, a bottomed cylindrical partition member formed of a porous material that permeates gas but not permeates the melt and is immersed in the melt in the storage container, and the interior of the partition member is placed under vacuum. Alternatively, a vacuum suction type degassing device characterized by having a suction means for suctioning the gas in the melt or the gas generated by the reaction between the melt and the components of the partition member under reduced pressure. (2) The vacuum suction type degassing device according to claim 1, further comprising a heating means for electrically heating the partition member.