Sb recovery method

Abstract

This method allows for the selective recovery of Sb relative to Bi from a substance containing Sb, Bi, and Pb, without using hydrofluoric acid solution. [Solution] A method for recovering Sb and related technologies are provided, comprising: a mass ratio adjustment step of adjusting the mass ratio of Bi to Pb (Bi / Pb) in a workpiece containing Sb, Bi, and Pb to less than 1.0; a first heating step of roasting the workpiece whose mass ratio has been adjusted in the mass ratio adjustment step at a temperature in the range of 250 to 350°C; a second heating step of roasting the workpiece under reduced pressure below atmospheric pressure after the first heating step to selectively volatilize the Sb-containing compounds; and a recovery step of recovering the Sb-containing compounds volatilized in the second heating step.

Claims

1. A mass ratio adjustment step to make the mass ratio of Bi to Pb (Bi / Pb) in a processed material containing Sb, Bi, and Pb less than 1.0, A first heating step involves roasting the workpiece whose mass ratio has been adjusted in the mass ratio adjustment step within a range of 250 to 350°C. Following the first heating step, a second heating step is performed in which the workpiece is roasted under reduced pressure below atmospheric pressure to selectively volatilize the Sb-containing compound. A recovery step for recovering the Sb-containing compound that has volatilized by the second heating step, A method for recovering Sb, comprising the following:

2. The method for recovering Sb according to claim 1, wherein the material to be treated is lead electrolytic slime.

3. The aforementioned Sb-containing compound is Sb ２ O ３ A method for recovering Sb according to claim 1 or 2, including the method described in claim 1 or 2.

4. The roasting temperature in the second heating step is Sb under reduced pressure. ２ O ３ The lower limit is set to a temperature 50°C higher than the temperature at which the saturated vapor pressure of Sb is reached. ２ O ３ A method for recovering Sb according to claim 1 or 2, wherein the upper limit of the temperature is 200°C higher than the temperature at which the saturated vapor pressure of Sb occurs.

5. The method for recovering Sb according to claim 1 or 2, wherein the second heating step is performed at 1000 Pa or less.

6. The mass ratio of Bi to Pb in the workpiece before the aforementioned mass ratio adjustment step is 1.0 or greater. The method for recovering Sb according to claim 1 or 2, wherein in the mass ratio adjustment step, Pb is added to the material to be processed before the mass ratio adjustment step is performed.

7. A mass ratio adjustment step in which Pb is added to a workpiece containing Sb, Bi, and Pb, and the mass ratio of Bi to Pb (Bi / Pb) is 1.0 or more, to make the mass ratio less than 1.0, A first heating step involves roasting lead electrolytic slime containing Sb and Pb in the range of 250 to 350°C, After the first heating step, the lead electrolytic slime is roasted under reduced pressure of 1000 Pa or less to obtain Sb ２ O ３ A second heating step in which an Sb-containing compound containing the above is selectively volatilized, A recovery step for recovering the Sb-containing compound that has volatilized by the second heating step, It has, The roasting temperature in the second heating step is 50°C higher than the temperature at which the saturated vapor pressure of Sb ２ O ３ is reached as the lower limit, and within the range where the upper limit is 200°C higher than the temperature at which the saturated vapor pressure of Sb ２ O ３ is reached. The method for recovering Sb according to claim 1.

8. The method for recovering Sb according to claim 1 or 2, wherein in the second heating step, SiC is placed at the bottom of the container in which the material to be treated is placed.

9. The method for recovering Sb according to claim 1 or 2, further comprising the step of adding graphite to the workpiece before the second heating step.

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