Method for efficiently separating indium-tin-silver ternary alloy

Abstract

The invention relates to a method for efficiently separating an indium-tin-silver ternary alloy, and belongs to the technical field of non-ferrous metal thermometallurgy. The method comprises the following steps: heating an indium-tin-silver ternary alloy until the indium-tin-silver ternary alloy is completely molten, then inserting a crystallization shaft, introducing cooling water into the crystallization shaft, enabling the crystallization shaft to slowly rotate and rise, enabling silver to crystallize on the crystallization shaft, and enabling indium and tin to be still melt; the obtained indium tin melt is put into an oxidation volatilization furnace to be melted, an oxygen agent is blown from the bottom, stannous oxide volatilizes after tin and indium are oxidized, stannous oxide is obtained in a condensation section, and indium oxide is still left in a crucible at the bottom. According to the method, the technological process is short, and efficient separation of silver, tin and indium of the indium-tin-silver ternary alloy can be achieved through the two technological steps of crystallization precipitation and oxidative volatilization.

Description

Technical Field

[0001] The present invention relates to a method for efficiently separating indium-tin-silver ternary alloy, belonging to the technical field of pyrometallurgy of non-ferrous metals. Background Art

[0002] Indium-tin-silver ternary alloy has good anti-welding and anti-burning properties, and is a good contact and contact material, which is widely used in relays, contactors, air switches, motor protectors, micro-switches, instruments, household appliances, automotive electrical appliances (load switches such as lamp switches and starting motors), leakage protection switches, etc. The value of each metal in the indium-tin-silver ternary alloy is high, and it is urgent to separate the metals in the indium-tin-silver ternary alloy and efficiently recycle each metal element. Summary of the Invention

[0003] Aiming at the problems and deficiencies existing in the above-mentioned prior art, the present invention provides a method for efficiently separating indium-tin-silver ternary alloy. The present invention is realized through the following technical solutions.

[0004] A method for efficiently separating indium-tin-silver ternary alloy, the steps of which include:

[0005] Step 1: Heat the indium-tin-silver ternary alloy to complete melting, then insert a crystallization shaft, and introduce cooling water into the crystallization shaft. Silver precipitates crystals on the crystallization shaft, and the remaining indium-tin melt is obtained;

[0006] Step 2: Put the indium-tin melt obtained in Step 1 into an oxidation volatilization furnace to melt, and introduce an oxidant from a spray gun. After tin and indium are oxidized, stannous oxide volatilizes, and indium oxide does not volatilize. Stannous oxide is obtained in the condensation section, and the remaining indium oxide is obtained.

[0007] In the indium-tin-silver ternary alloy in Step 1, the indium content is 40-90%, the tin content is 10-60%, the silver content is 5-20%, and the total content of indium, tin, and silver is 100%.

[0008] In Step 1, the indium-tin-silver ternary alloy is heated to 800-1000°C for complete melting.

[0009] In Step 1, the material of the crystallization shaft is graphite, and cooling water is introduced into the crystallization shaft to keep the temperature on the crystallization shaft at 600-800°C. The rotation speed of the crystallization shaft is 10-30 r / min, the lifting speed is 0.1-0.5 mm / min, and the crystallization time is 120-300 min.

[0010] In Step 1, the crystallization shaft is a hollow circular tube, and a partition is provided inside the circular tube to divide the circular tube into a water inlet pipe and a water outlet pipe; the bottom end of the partition is 10-30 mm away from the bottom of the circular tube to enable the mutual flow between the inlet water and the outlet water.

[0011] In the second step, the indium-tin melt is melted at a temperature of 400-800 °C, and then an oxidant is blown in from the spray gun, and it is oxidized and volatilized for 30-120 minutes under a pressure of 10-50 Pa.

[0012] The working principle of the present invention: Due to the large difference in the melting points of indium, tin and silver, by controlling the temperature distribution difference in the system, a crystallization axis is used to precipitate silver crystals to obtain pure silver products; in the range of 400-800 °C, an oxidant is added to the silver-tin melt to oxidize tin to stannous oxide, and indium reacts to form indium oxide. The saturated vapor pressures of stannous oxide and indium oxide are quite different, and stannous oxide is volatilized through the vacuum distillation process, and indium remains in the form of indium oxide, thus realizing the separation between silver, tin and indium.

[0013] The beneficial effects of the present invention are:

[0014] (1) The process flow is short. The indium-tin-silver ternary alloy can realize the separation between silver, tin and indium through two process steps of crystallization precipitation and oxidation volatilization.

[0015] (2) The process of the present invention is a full pyro-metallurgical process, which will not generate waste water and there is no waste water treatment cost.

[0016] (3) The indium-tin-silver ternary alloy can directly obtain pure silver by adopting this process.

[0017] (4) The stannous oxide and indium oxide produced by this process have high purity and can be used directly as materials. Description of the Drawings

[0018] Figure 1 is a schematic diagram of the process flow of the present invention;

[0019] Figure 2 is a schematic diagram of the melt crystallization and oxidation volatilization equipment and principle of the present invention;

[0020] Figure 3 Schematic diagram of the crystallization axis structure of the present invention. Detailed Embodiments

[0021] The present invention will be further described below in conjunction with the drawings and detailed embodiments.

[0022] Example 1

[0023] As Figure 1 and 2 shown, the method for efficient separation of indium-tin-silver ternary alloy includes the following steps:

[0024] Step 1: Heat the indium-tin-silver ternary alloy (83 wt% indium, 11 wt% tin, and 6 wt% silver) to 1000 °C until it completely melts. Then insert the crystallization shaft, pass cooling water into the crystallization shaft, silver crystals will precipitate on the crystallization shaft, and the remaining indium-tin melt will be obtained. The material of the crystallization shaft is graphite. Pass cooling water into the crystallization shaft to keep the temperature on the crystallization shaft at 600 °C. The rotation speed of the crystallization shaft is 10 r / min, the pulling speed is 0.1 mm / min, and crystallization is carried out for 120 min. As Figure 3 shown, the crystallization shaft is a hollow circular tube, and there is a partition inside the circular tube, which divides the circular tube into a water inlet pipe and a water outlet pipe. The bottom end of the partition is 10 mm away from the bottom of the circular tube to enable the mutual circulation between the inlet water and the outlet water. There is a power device at the upper part of the crystallization shaft to control the rotation and rising of the crystallization shaft at a certain speed.

[0025] Step 2: Put the indium-tin melt obtained in Step 1 into an oxidation volatilization furnace and melt it at 500 °C. Inject an oxidant (the oxidant is oxygen, and the addition amount is 0.5 - 5 ml / min) from the top-blowing spray gun, and carry out oxidation volatilization at a pressure of 50 Pa for 2 h. Stannous oxide is obtained in the condensation section, and indium oxide is obtained in the crucible.

[0026] The purity of the silver crystals obtained in this example is 98.14%, the purity of stannous oxide is 99.25%, and the purity of indium oxide is 98.57%.

[0027] Comparative Example

[0028] Heat the indium-tin-silver ternary alloy (83 wt% indium, 11 wt% tin, and 6 wt%) in a reactor to 1000 °C until it completely melts. Then directly control the temperature of the reactor to drop to 600 °C. After crystallization for 120 min, then discharge the indium-tin melt, and it is found that a large amount of silver crystals are doped in the indium-tin melt.

[0029] Judging from Example 1 and the comparative example, direct temperature control crystallization cannot effectively separate the silver product and the indium-tin melt.

[0030] Example 2

[0031] As Figure 1 and 2 shown, the method for efficient separation of the indium-tin-silver ternary alloy includes the following steps:

[0032] Step 1: Heat the indium-tin-silver ternary alloy (indium 69 wt%, tin 24 wt%, and silver 7 wt%) to 1000 °C until it completely melts. Then insert the rotary crystallization shaft, introduce cooling water into the rotary crystallization shaft, silver crystals will precipitate on the rotary crystallization shaft, and the remaining indium-tin melt will be obtained. The material of the rotary crystallization shaft is graphite. Introduce cooling water into the rotary crystallization shaft to keep the temperature on the crystallization shaft at 800 °C. The rotation speed of the rotary crystallization shaft is 20 r / min, the pulling speed is 0.5 mm / min, and the rotary crystallization shaft crystallizes for 200 min. As Figure 3 shown, the rotary crystallization shaft is a hollow circular tube. There are partitions inside the circular tube, which divide the circular tube into a water inlet pipe and a water outlet pipe. The bottom end of the partition is 20 mm away from the bottom of the circular tube, allowing the inflow and outflow of water to communicate with each other. There is a rotary power device at the upper part of the rotary crystallization shaft to control the rotation and lifting of the rotary crystallization shaft according to the rotation speed;

[0033] Step 2: Put the indium-tin melt obtained in Step 1 into an oxidation volatilization furnace and melt it at 600 °C. Inject an oxidant (the oxidant is oxygen, and the addition amount is 0.5 - 5 ml / min) from the top-blowing spray gun, add oxygen from the bottom, and oxidize and volatilize for 120 min at a pressure of 20 Pa. Stannous oxide will be obtained in the condensation section, and the remaining indium oxide will be obtained.

[0034] The purity of the silver crystals obtained in this example is 98.06%, the purity of stannous oxide is 99.81%, and the purity of indium oxide is 99.03%.

[0035] Example 3

[0036] As Figure 1 and 2 shown, the method for efficient separation of the indium-tin-silver ternary alloy includes the following steps:

[0037] Step 1: Heat the indium-tin-silver ternary alloy (indium 76 wt%, tin 18 wt%, and silver 5 wt%) to 1200 °C until it completely melts. Then insert the rotary crystallization shaft, introduce cooling water into the rotary crystallization shaft, silver crystals will precipitate on the rotary crystallization shaft, and the remaining indium-tin melt will be obtained. The material of the rotary crystallization shaft is graphite. Introduce cooling water into the rotary crystallization shaft to keep the temperature on the crystallization shaft at 700 °C. The rotation speed of the rotary crystallization shaft is 30 r / min, the pulling speed is 0.3 mm / min, and the rotary crystallization shaft crystallizes for 250 min. As Figure 3 shown, the rotary crystallization shaft is a hollow circular tube. There are partitions inside the circular tube, which divide the circular tube into a water inlet pipe and a water outlet pipe. The bottom end of the partition is 20 mm away from the bottom of the circular tube, allowing the inflow and outflow of water to communicate with each other. There is a rotary power device at the upper part of the rotary crystallization shaft to control the rotation and lifting of the rotary crystallization shaft according to the rotation speed;

[0038] Step 2: Put the indium-tin melt obtained in Step 1 into an oxidation volatilization furnace and melt it at 700 °C. Inject an oxidant (the oxidant is oxygen, and the addition amount is 0.5 - 5 ml / min) from the top-blown spray gun, and oxidize and volatilize it at a pressure of 10 Pa for 120 min to obtain stannous oxide in the condensation section and obtain the remaining indium oxide.

[0039] The purity of the silver crystals obtained in this example is 97.62%, the purity of stannous oxide is 99.89%, and the purity of indium oxide is 99.45%.

[0040] The specific embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A method for efficiently separating an indium-tin-silver ternary alloy, characterized in that the steps include: Step 1: The indium tin silver ternary alloy is completely melted, and then a crystallization axis is inserted. Cooling water is passed into the crystallization axis, and the crystallization axis slowly rotates and rises. The silver in the melt will precipitate into crystals on the crystallization axis when the temperature reaches the crystallization point, and the indium tin remains in the melt; Step 2: Put the indium tin melt obtained in step 1 into an oxidation volatilization furnace for melting, blow an oxidant from a spray gun, tin and indium are oxidized into stannous oxide and indium oxide, the tin oxide stannous oxide volatilizes, stannous oxide is obtained in the condensation stage, and indium oxide still remains in the crucible.

2. The method for efficiently separating an indium-tin-silver ternary alloy according to claim 1, characterized in that: In the step 1, the indium-tin-silver ternary alloy has an indium content of 40-90wt%, a tin content of 10-60wt%, and a silver content of 5-20wt%, and the total content of indium, tin, and silver is 100wt%.

3. The method for efficient separation of indium, tin and silver ternary alloy according to claim 1, characterized in that: The indium tin silver ternary alloy in step 1 is heated to 800-1000° C. and completely melted.

4. The method for efficient separation of indium, tin and silver ternary alloy according to claim 1, characterized in that: In the step 1, the material of the crystallization axis is graphite, cooling water is introduced into the crystallization axis to maintain the temperature of the crystallization axis at 600-800°C, the rotation speed of the crystallization axis is 10-30 r / min, the pulling speed is 0.1-0.5 mm / min, and the crystallization time is 120-300 min.

5. The method for efficient separation of indium, tin and silver ternary alloy according to claim 4, characterized in that: In the step 1, the crystallization axis is a hollow circular tube, and a partition is provided inside the circular tube to divide the circular tube into an inlet pipe and an outlet pipe; the bottom end of the partition is 10 to 30 mm away from the bottom of the circular tube, so that the inlet and outlet water can flow mutually.

6. The method for efficiently separating an indium-tin-silver ternary alloy according to claim 1, characterized in that: In the step 2, the indium tin melt is melted at a temperature of 400-800° C., and then an oxidant is blown into the melt from a spray gun, and the oxidative volatilization is carried out at a pressure of 10-50 Pa for 30-120 minutes.

Images