A method for recovering rhodium and iridium from tellurium displacement solution of copper anode slime

Abstract

The application discloses a method for recovering rhodium and iridium from a tellurium displacement solution of copper anode slime, and the rhodium and iridium in the tellurium displacement solution of the copper anode slime is recovered by sequentially adopting the methods of evaporation and concentration, oxalic acid nickel-copper precipitation, chlorine hydrolysis of the nickel-copper precipitation solution and the like. By adopting the method, the rhodium and iridium in the copper anode slime can be recovered completely, the direct recovery rate of the rhodium and iridium can reach more than 95%, and about 100m 3 of the tellurium displacement solution is generated per day, 20-30 Kg of the precious metal rhodium and iridium can be recovered per year, and good economic benefits are obtained, and the method can be popularized and applied to the recovery of various rhodium and iridium-containing materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgical process, in particular to a method for recovering rhodium and iridium from copper anode slime tellurium displacement solution. BACKGROUND

[0002] The copper anode slime tellurium displacement solution contains nickel, copper, selenium, tellurium and a small amount of rhodium and iridium, and the content is Ni: 1-2%, Cu: 30-60%, Se: 0.1-0.2%, Te: 1-1.5%, Rh: 0.0002g / L, Ir: 0.001-0.002g / L. About 100m 3 of tellurium displacement solution is sent to the copper salt process to extract copper sulfate every day, and the small amount of rhodium and iridium in it is finally left in the waste residue and cannot be purified, causing the loss of valuable rare metals. SUMMARY

[0003] The purpose of the present application is to provide a method for recovering rhodium and iridium from copper anode slime tellurium displacement solution, to realize the recovery and utilization of valuable metals rhodium and iridium, and to realize good economic benefits.

[0004] In order to achieve its purpose, the present application adopts the following technical scheme:

[0005] A method for recovering rhodium and iridium from copper anode slime tellurium displacement solution, comprising the following steps:

[0006] Step one, the copper anode slime tellurium displacement solution is concentrated, and the liquid alkali is added to adjust the pH to 1-1.5;

[0007] Step two, heat to 80-85℃, add oxalic acid, constant temperature reaction 1-2h, cool, centrifuge, filter, and wash the filter residue until the washing liquid is colorless;

[0008] Step three, concentrate the filtrate, add liquid alkali to adjust the pH to 13, heat to 70-80℃, and pass chlorine gas until the pH is 6-7;

[0009] Step four, add liquid alkali to adjust the pH to 13, heat to 70-80℃, and pass chlorine gas until the pH is 7-8;

[0010] Step five, add liquid alkali to adjust the pH to 13, heat to 70-80℃, and pass chlorine gas until the pH is 8-9; repeat the liquid alkali adding and heating and chlorine gas passing operation of steps three to five until the supernatant is colorless or light yellow transparent clear liquid, and the hydrolysis is completed;

[0011] Step six, solid-liquid separation, to obtain rhodium and iridium hydrolysis residue, and the rhodium and iridium hydrolysis residue is washed with hot water for multiple times and then transferred to the purification process for further separation and purification.

[0012] As a further optimization of the technical scheme of the present application, the liquid alkali is sodium hydroxide solution, preferably 40% sodium hydroxide solution.

[0013] Further, in step one, the copper anode slime tellurium displacement solution is concentrated to 500-1000L.

[0014] Further, in step two, the amount of oxalic acid added is 1.5-2 times the theoretical amount, preferably 2 times.

[0015] Further, in step three, the filtrate is concentrated to 400-600L.

[0016] The beneficial effects of the present application are:

[0017] 1. The present application can recover rhodium and iridium in copper anode slime, and the direct recovery rate of rhodium and iridium can reach more than 95%, about 100m 3 of tellurium displacement solution is produced per day, and 20-30Kg of precious metals rhodium and iridium can be recovered per year, achieving good economic benefits.

[0018] 2. The present application can be applied to the recovery of various materials containing rhodium and iridium. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The process flow chart of the present application for recovering rhodium and iridium from copper anode slime tellurium displacement solution. DETAILED DESCRIPTION

[0020] The present application will be further described in detail below in combination with the drawings and specific examples.

[0021] Example 1

[0022] 1000L of tellurium displacement solution containing Ni: 1.3%, Cu: 33%, Se: 0.12%, Te: 1.2%, Rh: 0.0002g / L, Ir: 0.0012g / L is added to the reaction kettle and evaporated and concentrated to 500L, 40% sodium hydroxide solution is added to adjust the pH to 1.5, and the temperature is raised to 80℃, after sampling analysis and calculation, 2 times the theoretical amount of oxalic acid is added, and the temperature is kept constant for 1h, then cooled, centrifuged and filtered to obtain copper-nickel residue and 650L of filtrate; the residue is washed until the washing liquid is colorless, then packaged for subsequent treatment, the filtrate is concentrated to 400L, 40% sodium hydroxide solution is added to adjust the pH to 13, the temperature is raised to 70℃, and chlorine gas is passed until the pH is 6; 40% sodium hydroxide solution is added to adjust the pH to 13, the temperature is raised to 75℃, and chlorine gas is passed until the pH is 7; liquid alkali is continuously added to adjust the pH to 13, the temperature is raised to 75℃, and chlorine gas is passed until the pH is 9; the supernatant is a colorless or light yellow transparent clear liquid, the liquid is subjected to solid-liquid separation to obtain 3Kg of hydrolysis residue containing ∑Rh + Ir = 1.35g, the direct recovery rate of rhodium and iridium is 96.4%, and the hydrolysis residue is washed with hot water several times and then transferred to the purification process for further separation and purification.

[0023] Example 2

[0024] 1000 L of tellurium-replaced solution containing Ni: 1.4%, Cu: 46%, Se: 0.16%, Te: 1.5%, Rh: 0.0002 g / L, Ir: 0.0018 g / L was added into a reaction kettle and concentrated to 500 L by evaporation. 40% sodium hydroxide solution was added to adjust the pH to 1. The temperature was raised to 85°C. After sampling and analysis, the theoretical amount of oxalic acid was added, which was 1.5 times the amount calculated. After constant temperature reaction for 2 h, cooling and centrifugal filtration, copper-nickel residue and 700 L of filtrate were obtained. The residue was washed until the washing liquid was colorless, then packaged for subsequent treatment. The filtrate was concentrated to 600 L. 40% sodium hydroxide solution was added to adjust the pH to 14. The temperature was raised to 80°C. Chlorine gas was passed until the pH was 7. Then 40% sodium hydroxide solution was added to adjust the pH to 14. The temperature was raised to 80°C. Chlorine gas was passed until the pH was 8. 40% sodium hydroxide solution was continuously added to adjust the pH to 14. The temperature was raised to 80°C. Chlorine gas was passed until the pH was 8. The supernatant was a colorless or light yellow transparent clear liquid. The liquid was subjected to solid-liquid separation to obtain 3.8 kg of hydrolysis residue containing ∑Rh + Ir = 1.91 g, with a direct recovery rate of rhodium and iridium of 95.5%. The hydrolysis residue was washed with hot water several times and then transferred to the purification process for further separation and purification.

Claims

1. A method for recovering rhodium and iridium from copper anode mud after tellurium displacement, characterized in that, The method includes the following steps: Step 1: Concentrate the solution after copper anode mud and tellurium replacement, and adjust the pH to 1-1.5 by adding liquid alkali; Step 2: Heat to 80-85℃, add oxalic acid (1.5-2 times the theoretical amount), react at a constant temperature for 1-2 hours, cool, centrifuge, and filter to obtain copper-nickel precipitate slag and filtrate; wash the copper-nickel precipitate slag until the washing liquid is colorless. Step 3: Concentrate the filtrate, add liquid alkali to adjust the pH to ≥13, raise the temperature to 70-80℃, and purge with chlorine gas until the pH is 6-7; Step 4: Add liquid alkali to adjust pH to ≥13, raise the temperature to 70-80℃, and purge with chlorine gas until pH is 7-8; Step 5: Add liquid alkali to adjust pH to ≥13, raise the temperature to 70-80℃, and purge chlorine gas until pH is 8-9; repeat steps 3 to 5 to add liquid alkali, raise the temperature, and purge chlorine gas until the supernatant is a colorless or pale yellow transparent clear liquid, thus completing hydrolysis; Step 6: Solid-liquid separation to obtain rhodium-iridium hydrolysate residue. The rhodium-iridium hydrolysate residue is washed multiple times with hot water and then transferred to the purification process for further separation and purification.

2. The method for recovering rhodium and iridium from the tellurium slurry after copper anode mud replacement according to claim 1, characterized in that, In step one, the copper anode mud tellurium replacement solution is concentrated to 500-1000L.

3. The method for recovering rhodium and iridium from the tellurium sludge after replacement in copper anode mud according to claim 1, characterized in that, In step two, the amount of oxalic acid added is twice the theoretical amount.

4. A method for recovering rhodium and iridium from copper anode mud after tellurium displacement, according to any one of claims 1-3, characterized in that, In step three, the filtrate is concentrated to 400-600L.

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