JP2958504B2 - Method for recovering In from In-Sb alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an In-Sb alloy
n for recovering n.

[0002]

2. Description of the Related Art In-Sb alloy is, for example, 50% by weight.
It is used for Hall elements and infrared detectors as compound semiconductors containing In before and after. Since it is difficult to reuse In-Sb alloy scrap by a simple process, a method of recovering expensive In from the scrap has been studied.

As the above method, (1) HCl, H ₂ SO
Leaching due _4, the (2) Sb content 0.5
Electrolytically refining the material whose composition has been adjusted to 0% by weight as an anode; (3) volatilizing chloride from the melt;
(4) A method of, for example, transferring from a melt to dross has been proposed.

[0004]

However, each of these methods has a problem that the recovery rate of In is poor. In view of the above circumstances, an object of the present invention is to provide a method for recovering In from an In-Sb alloy scrap with high yield.

[0005]

Means for Solving the Problems The present invention, as to achieve the above object, the In-Sb alloy, metal Pb, the In at least one of metal Sn and metal Bi
-2.5 to 20 weight times the amount of Sb contained in the Sb alloy
Then, the mixture is heated and melted to form a composite, and while maintaining the temperature of the composite at 350 to 500 ° C., the chloride is reacted with the composite to produce dross from the composite. This is a method for recovering In from an In—Sb alloy, which is characterized by separation and recovery.

[0006]

In the method of the present invention, first, an In-Sb alloy and at least one of metal Pb, metal Sn and metal Bi are heated and melted to form a composite. Metal Pb,
The reason for adding at least one of the metal Sn and the metal Bi is to efficiently transfer In into dross in a step of reacting a chlorinating agent at 350 to 500 ° C, which will be described later. This is because the addition of at least one of metal Pb, metal Sn and metal Bi turns the alloy into a molten material at the above reaction temperature, so that volatilization of In as InCl can be ignored, and that the added metal This is probably because the affinity for Cl is smaller than that of In.

The amount of addition is preferably 2.5 to 20 times the weight of Sb contained in the In-Sb alloy. If it is less than 2.5 times by weight, the melting point of the alloy obtained by the above-mentioned addition increases, and the alloy cannot be maintained in a molten state at the above-mentioned reaction temperature. Is reduced, and the recovery rate of In is likely to be reduced. Among the above metals, Pb which is easily available on the market
Is preferred.

[0008] Next, the temperature of the obtained integrated bank is set to 350 to
While maintaining the temperature at 500 ° C., the chloride is reacted with the alloy to form dross. When a chlorinating agent is allowed to react with the alloy, In has a greater affinity for Cl than Sb or the metal, so that In becomes InCl and migrates to dross on the melt.

The reason why the temperature of the melt to be maintained is 350 to 500 ° C. is that if the temperature is lower than 350 ° C., the fluidity of the melt is low and the above-mentioned reaction does not sufficiently occur. The separation between the dross phase and the alloy phase is reduced, and In
This is because Cl volatilization increases.

Examples of the chlorinating agent include ammonium chloride and chlorine gas, and ammonium chloride is preferred in terms of handling. It is preferable to use the chlorinating agent in which the operation of collecting dross is performed a plurality of times each time to end the use, rather than being completed once. Ammonium chloride 1
It is preferable that the amount used each time is 0.1 to 1% by weight of the total financial body. If the amount is less than 0.1% by weight, the amount of dross generated is small, and the above reaction is difficult to occur sufficiently. On the other hand, if it exceeds 1% by weight, the amount of dross generated increases, the In content in the dross decreases, and Recovery rate tends to decrease.

The dross generated and separated and recovered from the joint financial entity is similarly reacted with another joint financial entity as required, and
After the dross has a higher quality, for example, high purity In can be obtained by the following method. That is, dross is dissolved in excess hydrochloric acid, the pH is adjusted to about 1 with an alkaline aqueous solution, Pb and Sb are mainly precipitated, and a reducing agent such as Zn powder is added to a solution obtained by separating to thereby obtain cement In. Precipitate. The precipitated In is dissolved by adding caustic soda to obtain crude In. The crude In thus obtained is cast into an anode and electrolytically refined to obtain high-purity In.

[0012]

Next, an embodiment of the present invention will be described. Example 48.5% by weight of In (hereinafter referred to as% by weight), 67.1 kg of alloy scrap substantially composed of Sb, and 300 kg of metal Pb were charged into a graphite crucible and heated and melted at 400 ° C. Next, 1.5 kg of ammonium chloride was added, and after sufficiently stirring for about 1 hour, dross formed on the melt was scooped and collected with a ladle. Such an operation 2
Performed four times.

The results were as follows. That is, 1
The quality of the second dross is 50.3% In and 24.6% Pb.
%, Sb 0.02%, and the 24th time, dross grade was In12.7%, Pb61.3%, Sb0.28%
The grade of the alloy is 0.94% In, 88.0% Pb,
Sb was 11.1%. The total amount of the obtained dross was 82.6 kg, and the average quality was In35.8.
%, Pb 49.9% and Sb 0.04%. The alloy from which dross was separated 24 times was 294 kg.

It can be seen that by such a treatment, there is almost no loss of In due to volatilization of InCl and the like can be recovered in dross with high yield.

The total amount of dross recovered is 36% hydrochloric acid 11
The solution was dissolved in 0 kg with stirring at room temperature, and the pH was adjusted to 1.5 with a 250 g / liter sodium hydroxide solution.
The formed precipitate was separated and removed by filtration to obtain a 260 liter filtrate. While stirring the filtrate, Zn powder 29.7 was added.
kg was added to precipitate In. The obtained cement I
n and 2.0 kg of caustic soda were placed in a stainless steel crucible and melted at 250 ° C.
7.8 kg of crude In was obtained. The grade of this crude In is In
99.4%, Pb 0.44%, Sb 0.01%.

[0016]

According to the method of the present invention, In can be easily recovered in dross from In-Sb alloy scrap in a high yield.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C22B 58/00

Claims (2)

(57) [Claims] To 1. A In-Sb alloy, metal Pb, Sn metal
And at least one of metal Bi and In-S
2.5 to 20 weight times the amount of Sb contained in the b alloy
Then, it is heated and melted to form a composite, and while maintaining the temperature of the composite at 350 to 500 ° C., the chloride is reacted with the composite to separate generated dross from the composite. A method for recovering In from an In-Sb alloy, the method comprising recovering In. 2. The chlorinating agent is ammonium chloride,
Each time, 0.1 to 1% by weight of ammonium chloride
2. The In according to claim 1, wherein In is used.
-Method for recovering In from Sb alloy.