JPH0435537B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for recovering low-boiling components used in the production of alloy materials.

[Background technology]

BACKGROUND ART Conventionally, a conductive layer of a good conductor such as copper is formed on the surface of a brass material by plating, thereby reducing the contact resistance of the brass material. The treated brass material is used as a terminal base material and the like. In this way, by forming a conductive layer on the surface of the brass material, the raw material cost is lower than when using a highly conductive material such as copper material as is, and the contact resistance is about the same. Benefits arise. However, the conventional method described above requires a large plating apparatus, resulting in low productivity and high processing costs. Furthermore, the conductive layer formed by plating is easily peeled off, so it is extremely difficult to bend the brass material, which has become a hoop material, into parts after plating. I also had the above problem.

In addition to plating, there are other techniques for forming dissimilar metals on the surface of a metal plate, such as thermal spraying and metal sheet welding. However, there were problems such as high processing costs and poor quality of the brass material obtained.

Therefore, by heating the brass material under reduced pressure to evaporate the zinc on the surface, it is possible to produce a brass material 1 having a conductive layer 1a with a high copper content on the surface, as shown in FIG. thought out. If the brass material is manufactured in this way, there is no need to use other metal materials, and compared to the case of plating, the manufacturing equipment can be smaller and the productivity is higher.
Moreover, the processing cost is low, and the conductive layer of the resulting brass material has little risk of peeling.

The manufacturing method of this brass material will be specifically explained. This method of manufacturing brass material is carried out using, for example, a manufacturing apparatus as shown in FIG. As shown in the figure, this manufacturing device is equipped with an unwinding drum 2 and a winding drum 3, and the unwinding drum 2 is equipped with a brass material 4, which is a raw material used as a hoop material, wound around the winding drum. A brass material 5 that has been subjected to a dezincing treatment is wound around the wire 3. A preheater 6, a vacuum heating furnace 7, and a rolling mill 8 are provided in order between the unwinding drum 2 and the winding drum 3, and the brass material 4 sent from the unwinding drum 2 is passed through these in order. It's starting to pass. The preheater 6 is for removing oil, moisture, etc. adhering to the brass material 4 and drying it. A heating chamber 9 is provided in the center of the vacuum heating furnace 7, and two preliminary vacuum chambers are provided before and after the heating chamber 9, namely, preliminary vacuum chambers 10a and 10b at the front, and preliminary vacuum chambers 10c and 10 at the rear.
d is provided. Preliminary vacuum chambers 10a to 10d
is provided to increase the degree of vacuum in the heating chamber 9 by increasing the degree of vacuum (degree of reduced pressure) in order toward the heating chamber 8. Each of the preliminary vacuum chambers 10a and 10d is provided with an inlet 11 for inert gas such as nitrogen gas. An inert gas such as nitrogen gas is introduced to remove oxygen from the heating chamber 9 to prevent oxidation of the brass material 4. A heating device (heating section) 12 is provided in the heating chamber 9.
is located. Although not shown in the figure, a pressure reducing device such as a vacuum pump is disposed in the vacuum heating furnace 7. Further, a zinc recovery means, such as a metal plate, for recovering zinc by adhering it thereto is arranged in the heating chamber.

Using this device, brass material is produced in the following manner. The raw material brass material 4 mounted on the unwinding drum 2 is sent to a preheating chamber 6 to remove oil and water and dried, and then sent to a heating chamber 7 where it is heated under reduced pressure. For example, the air pressure inside the heating chamber
When the vacuum is about 10 ^-2 to 10 ^-4 Torr (higher vacuum than about 10 ^-2 Torr), the brass material is heated to about 500 to 900°C. Zinc, a low boiling point component, has a temperature of 930 at 1 atm.
It evaporates at a boiling point of 10 ^-2 to 10 ^-4 Torr, which is close to a complete vacuum, at a temperature of 500 to 900°C. On the other hand, copper, which is a high boiling point component, has a boiling point of 2582° C. at 1 atmosphere, which is considerably higher than that of zinc, and hardly evaporates at the above pressure and temperature. Utilizing such a difference in boiling point (difference in vapor pressure) between zinc and copper, zinc on the surface of the brass material 4 is selectively evaporated and removed. Then, a conductive layer containing a large amount of copper is formed on the surface of the brass material.
The evaporated zinc is recovered by attaching it to a zinc recovery means.

After dezincing treatment, the brass material 4 is transferred to a rolling mill 8.
It is then rolled to a predetermined thickness. Immediately after the treatment, the brass material 4 has improved electrical properties due to high-temperature heating, but on the other hand, the mechanical properties, that is, the strength, have decreased due to evaporation of zinc and the formation of pores, and the surface has become rough. There is. However, this rolling improves the strength and makes the surface flat. The brass material 5 obtained by rolling is wound around a winding drum 3. In this way, a brass material as shown in FIG. 1 is obtained.

However, in this method of manufacturing brass materials, zinc is recovered by adhering it to the zinc recovery means installed in the heating chamber, so even if the zinc adheres to the zinc recovery means, the temperature is high enough to generate kinetic energy. For the reasons mentioned above, there is a high risk that the zinc will evaporate again. This has caused problems such as a decrease in the zinc recovery rate and an increased risk of zinc re-adhering to the brass.

[Purpose of the invention]

This invention was made in view of the above circumstances, and it is possible to reduce the possibility that the recovery rate of low boiling point components such as zinc will decrease or that the low boiling point components will adhere to alloy materials such as brass materials again. The purpose is to provide a collection method for

[Disclosure of the invention]

The inventors have conducted repeated research to solve the above problems. As a result, a cooling chamber, whose internal pressure is maintained at almost atmospheric pressure using inert gas, is connected to the outlet of the heating chamber, and a recovery chamber equipped with a cooling device is connected to the cooling chamber. They found that the zinc can be recovered by heating the brass material, passing it through a cooling chamber, sending the evaporated zinc together with an inert gas to a recovery chamber, and cooling this gas mixture in the recovery chamber. Ta. In addition, we discovered that even when processing alloy materials other than brass materials, which consist of components with different boiling points, the same effect can be obtained by recovering the low boiling point components in the same way, and we have hereby completed this invention. did.

Therefore, the present invention provides the following advantages: In the heating chamber,
When an alloy material consisting of components with different boiling points is heated to evaporate the low boiling point components on the surface to create an alloy material with a layer containing many high boiling point components on the surface, the internal pressure is brought to almost atmospheric pressure by an inert gas. A cooling chamber is connected to the outlet of the heating chamber, and a recovery chamber equipped with a cooling device is connected to the cooling chamber. After the alloy material is heated, it is passed through the cooling chamber and evaporated. A low boiling point component recovery method is provided, which is characterized in that the low boiling point components are sent together with an inert gas from a cooling chamber to a recovery chamber, and the low boiling point components are recovered by cooling this mixed gas in the recovery chamber. This is the summary. This invention will be explained in detail below.

FIG. 3 shows the arrangement of the heating chamber, the cooling chamber and the recovery chamber used in the method for recovering low boiling point components according to the present invention. As shown in the figure, heating chamber 13
A cooling chamber 14 is connected to the outlet 13a of the cooling chamber 1.
4 is connected to a recovery chamber 15 by pipes 16 and 17. A circulation pump 18 is arranged in the piping 17 . A heating device 13b is arranged in the heating chamber 13, and an inlet 13c and an outlet 13a of the heating chamber 13 are arranged.
Vacuum pumps 19, 19 are connected nearby. A vacuum pump 19 and inert gas supply means such as an inert gas cylinder 20 are connected to the cooling chamber 14 . As shown in FIG. 5, inside the recovery chamber 15, a plate-shaped heat exchanger (cooling device) 21 is disposed, which is provided with a passage 21a through which a refrigerant such as cooling water passes. . Here, the heat exchangers 21... protrude alternately from the left and right walls of the recovery chamber 15, with their tips pointing diagonally upward from the left wall in the drawing, and their tips pointing diagonally downward from the right wall. It is located in A passage 22 is created by these heat exchangers 21.

Using the cooling chamber 14 and recovery chamber 15 arranged as described above, the low boiling point component recovery method according to the present invention is carried out, for example, in the following manner.

First, the pressure inside the heating chamber 13 and the cooling chamber 14 is reduced by the vacuum pumps 19, and the pressure inside the cooling chamber 14 is brought to approximately atmospheric pressure using an inert gas. Since the outlet 13a of the heating chamber 13 (inlet of the cooling chamber 2) is only slightly larger than the cross section of the alloy material 23 that has become the hoop material, almost no inert gas passes from the cooling chamber 14 to the heating chamber 13. , Therefore, heating chamber 1
The degree of vacuum within the chamber is maintained. Then, the pump 18 operates the cooling chamber 14 and the recovery chamber 1.
Circulate inert gas for 5 minutes. Next, the temperature inside the heating chamber 13 is set to a predetermined temperature using the heating device 13b. After preheating the alloy material 23, the heating chamber 1
3, the alloy material 23 is heated, and then the alloy material 23 is sent to the cooling chamber 14. In the cooling chamber 14, the alloy material 23 is left to cool down to about room temperature using the convection effect of inert gas. Since the gas in the room is an inert gas, the alloy material 23 cools without being oxidized. On the other hand, in the cooling chamber 14, since the indoor pressure is approximately atmospheric pressure, the low boiling point components evaporated from the alloy material 23 have a small mean free path and are scattered. Therefore, the low boiling point components are sent into the recovery chamber 15 together with the inert gas without substantially adhering to the inner wall surface of the cooling chamber 14. As shown in FIG. 5, a gas mixture consisting of a low boiling point component 24 and an inert gas 25 is sent from a pipe 16 to a passage 22 in the recovery chamber 15. While passing through the passage 22, the low boiling point component 24 is cooled and adheres to the heat exchanger 21,
Only the inert gas 25 is sent from the pipe 17 to the cooling chamber 14 again. Thereafter, the alloy material 23 is processed in the same manner as in the prior art. For example, it is subjected to rolling treatment and the like to become an alloy material for products.

When a brass material is used as the alloy material, it is preferable to adjust the temperature and pressure distribution in the heating chamber and the cooling chamber so that they are as shown in FIG. 4. In the figure, the solid line indicates temperature, and the dashed line indicates atmospheric pressure. In other words, as shown in the figure, the temperature in the heating chamber is 500 to 900℃ and the pressure is 10 ^-2 to ^{10 -4} Torr, and the temperature in the cooling chamber is lower at the outlet by adjusting the flow rate of inert gas. It is recommended that the pressure be approximately atmospheric pressure.

In the low boiling point component recovery method according to the present invention, the low boiling point components are scattered in an inert gas atmosphere at atmospheric pressure in a cooling chamber connected to the outlet of the heating chamber, and then the low boiling point components are removed. By sending the low boiling point components from the heating chamber to a separate recovery chamber and recovering them there, there is almost no risk that the recovered low boiling point components will evaporate again, and the recovery rate of the low boiling point components will be high. Furthermore, since there is very little possibility that the low boiling point components will adhere to the alloy material again, the quality of the obtained alloy material will be high.

Note that it is not necessary to circulate the inert gas between the cooling chamber and the recovery chamber as in the above embodiment.

〔Effect of the invention〕

In the low boiling point component recovery method according to the present invention, an alloy material consisting of components with different boiling points is heated in a heating chamber, and the low boiling point components on the surface are evaporated, so that the alloy material has a layer containing many high boiling point components on the surface. When making a heating chamber, a cooling chamber whose internal pressure is maintained at almost atmospheric pressure with an inert gas is connected to the outlet of the heating chamber, and a recovery chamber equipped with a cooling device is connected to the cooling chamber. After heating the alloy material, it is passed through a cooling chamber, and the low-boiling point components that evaporate are sent together with an inert gas from the cooling chamber to the recovery chamber.The low-boiling point components are recovered by cooling this mixed gas in the recovery chamber. As a result, the recovery rate of low boiling point components is increased. Furthermore, the possibility that the low-boiling point components will adhere to the alloy material again is extremely reduced, and the quality of the obtained alloy material will be high.

[Brief explanation of drawings]

Figure 1 is a partially cutaway perspective view of a brass material with a layer with a high copper content on its surface, Figure 2 is a schematic explanatory diagram of the manufacturing equipment used to manufacture the brass material, and Figure 3 is an explanatory diagram of the layout of the cooling room and recovery room,
FIG. 4 is a graph showing the distribution of temperature and pressure in the heating chamber and the cooling chamber, and FIG. 5 is a longitudinal sectional view of the recovery chamber. 13...Heating chamber, 13a...Heating chamber outlet, 1
4... Cooling chamber, 15... Recovery chamber, 21... Heat exchanger (cooling device), 23... Alloy material, 24... Low boiling point component, 25... Inert gas.

Claims (1)

[Scope of Claims] 1. In a heating chamber, an alloy material consisting of components with different boiling points is heated to evaporate the low boiling point components on the surface to produce an alloy material with a layer containing many high boiling point components on the surface, A cooling chamber whose internal pressure is maintained at almost atmospheric pressure with inert gas is connected to the outlet of the heating chamber, and a recovery chamber equipped with a cooling device is connected to the cooling chamber. After heating, the gas is passed through a cooling chamber, and the low-boiling components that evaporate are sent together with an inert gas from the cooling chamber to the recovery chamber, and the low-boiling components are recovered by cooling this gas mixture in the recovery chamber. A method for recovering low boiling point components. 2. The low boiling point component recovery method according to claim 1, wherein an inert gas is circulated between the cooling chamber and the recovery chamber.