阅读说明：本技术 一种铑铱分离精炼工艺 (Rhodium-iridium separation refining process ) 是由 姬亚沣 马会强 马帅 董华绘 姬利红 衡振平 于 2021-09-10 设计创作，主要内容包括：本发明涉及一种铑铱分离精炼工艺,包括以下步骤：S1：制备待分离的铑铱溶液,控制铑质量浓度为45～55g/L,氢离子浓度为3.5-4.5mol/L；S2：将铑铱溶液加热至80～90℃,再加入800～1200ml的过氧化氢进行搅拌,之后冷却待用S3：分别制备3.5～4.5mol/L的盐酸溶液和8～12％的氢氧化钠溶液；S4：在磷酸三丁酯内加入等体积的S3制得的盐酸溶液进行预平衡2次,静置后放出液相,并加入800～1200ml的过氧化氢,搅拌后备用；S5：将S4处理过的溶液和S1制备的铑铱溶液混合并搅拌8～12分钟,静置后放出萃余液；S6：取S3配制的氢氧化钠溶液8～12L,对S5的有机相进行反洗2～3次,放出液相。最终可得到99.9～99.9％左右成品铑粉,以及99.9～99.9％的海绵铱粉,克服了铑铱分离不彻底的难题。(The invention relates to a rhodium-iridium separation refining process, which comprises the following steps: s1: preparing a rhodium-iridium solution to be separated, and controlling the mass concentration of rhodium to be 45-55 g/L and the concentration of hydrogen ions to be 3.5-4.5 mol/L; s2: heating the rhodium iridium solution to 80-90 ℃, adding 800-1200 ml of hydrogen peroxide, stirring, and cooling for later use, wherein the mass ratio of S3: respectively preparing 3.5-4.5mol/L hydrochloric acid solution and 8-12% sodium hydroxide solution; s4: adding an isometric hydrochloric acid solution prepared from S3 into tributyl phosphate for pre-balancing for 2 times, standing, discharging a liquid phase, adding 800-1200 ml of hydrogen peroxide, and stirring for later use; s5: mixing the solution treated by the S4 with the rhodium-iridium solution prepared by the S1, stirring for 8-12 minutes, standing, and discharging raffinate; s6: and 8-12L of sodium hydroxide solution prepared in S3 is taken, the organic phase of S5 is backwashed for 2-3 times, and the liquid phase is discharged. And finally, about 99.9-99.9% of rhodium powder and 99.9-99.9% of sponge iridium powder can be obtained, and the problem that rhodium and iridium are not completely separated is solved.)

1. A rhodium-iridium separation refining process is characterized in that: the method comprises the following steps:

s1: preparing a rhodium-iridium solution to be separated, and controlling the mass concentration of rhodium to be 45-55 g/L and the concentration of hydrogen ions to be 3.5-4.5 mol/L;

s2: heating 18-22L of rhodium-iridium solution prepared by S1 to 80-90 ℃, adding 800-1200 ml of hydrogen peroxide, stirring, and cooling for later use

S3: respectively preparing 3.5-4.5mol/L hydrochloric acid solution and 8-12% sodium hydroxide solution;

s4: adding an isometric hydrochloric acid solution prepared from S3 into tributyl phosphate for pre-balancing for 2 times, standing, discharging a liquid phase, adding 800-1200 ml of hydrogen peroxide, and stirring for later use;

s5: mixing the solution treated by the S4 with the rhodium-iridium solution prepared by the S1, stirring for 8-12 minutes, standing, and discharging raffinate;

s6: and 8-12L of sodium hydroxide solution prepared in S3 is taken, the organic phase of S5 is backwashed for 2-3 times, and the liquid phase is discharged.

2. The rhodium-iridium separation refining process of claim 1, wherein: and (3) reducing raffinate obtained from S5 by formic acid or hydrazine hydrate, calcining and reducing by hydrogen to obtain sponge rhodium.

3. The rhodium-iridium separation refining process of claim 1, wherein: and filtering, concentrating, oxidizing, precipitating, calcining and reducing the liquid phase in the S6 by hydrogen to obtain the sponge iridium.

4. The rhodium-iridium separation refining process of claim 3, wherein: the oxidative precipitation is carried out by adding hydrochloric acid, sodium sulfate and ammonium chloride into concentrated iridium solution, and stirring for precipitation.

5. The rhodium-iridium separation refining process of claim 1, wherein: and adding 18-22L of hydrochloric acid solution prepared in S3 into the organic phase of S6, and stirring for 4-6 minutes to complete the regeneration of tributyl phosphate.

6. The rhodium-iridium separation refining process of claim 1, wherein: and (3) carrying out 2-3-grade extraction on the raffinate obtained from the S5 according to the sequence of S4 and S5 until the content of iridium in the raffinate is detected to be at the lower limit of spectral analysis.

7. The rhodium-iridium separation refining process of claim 1, wherein: the rhodium-iridium solution in S1 does not contain noble metal cations.

8. The rhodium-iridium separation refining process of claim 1, wherein: the preparation of the rhodium-iridium solution in S1 comprises the following steps: a) dissolving aqua regia into a solution containing rhodium and iridium; b) controlling the acidity of the solution prepared in the step a) by nitrate removal, concentration and acid removal; c) exchanging with cation resin to remove base metal cations in the solution prepared in step b).

Technical Field

The invention relates to the technical field of rhodium-iridium separation, in particular to a rhodium-iridium separation refining process.

Background

The rhodium iridium has similar chemical properties, and the existing state of the rhodium iridium in a hydrochloric acid medium is very complex, and the rhodium iridium is generally separated and purified after other metals are basically separated. Early, commercial rhodium-iridium separations were based on the use of H₂S or Na₂S precipitation of rhodium from solutions of nitroso complexes followed by (NH)₄)₂S, but the method is difficult to filter and cannot achieve effective separation. KHSO is used in most plants₄Melting rhodium, transferring rhodium into solution, refining with nitrite complexation method to obtain 99.9% rhodium powder, alkali melting iridium-containing residue, transferring into solution, and adding (NH)₄)₂IrCl₆Repeated crystallization and calcination are carried out to obtain 99.9 percent iridium powder. The rhodium iridium in solution is usually reacted with (NH) in the presence of an oxidant₄)₂IrCl₆The precipitate is separated from the rhodium. The main disadvantages of these methods are: the process is long, the operation is complex, the labor condition is poor, the direct yield is low, and the reagent consumption is large.

Disclosure of Invention

The invention aims to provide a rhodium-iridium separation refining process, which aims to solve the problems of complex operation and low direct yield of the existing rhodium-iridium separation.

In order to achieve the purpose, the invention adopts the following technical scheme: a rhodium-iridium separation refining process comprises the following steps:

s1: preparing a rhodium-iridium solution to be separated, and controlling the mass concentration of rhodium to be 45-55 g/L and the concentration of hydrogen ions to be 3.5-4.5 mol/L;

s2: heating 18-22L of rhodium-iridium solution prepared in S1 to 80-90 ℃, adding 800-1200 ml of hydrogen peroxide, stirring, and cooling for later use;

s3: respectively preparing 3.5-4.5mol/L hydrochloric acid solution and 8-12% sodium hydroxide solution;

s4: adding an isometric hydrochloric acid solution prepared from S3 into tributyl phosphate for pre-balancing for 2 times, standing, discharging a liquid phase, adding 800-1200 ml of hydrogen peroxide, and stirring for later use;

s5: mixing the solution treated by the S4 with the rhodium-iridium solution prepared by the S1, stirring for 8-12 minutes, standing, and discharging raffinate;

s6: and 8-12L of sodium hydroxide solution prepared in S3 is taken, the organic phase of S5 is backwashed for 2-3 times, and the liquid phase is discharged.

Further preferably, the raffinate obtained in S5 is reduced with formic acid or hydrazine hydrate, calcined, and reduced with hydrogen to obtain rhodium sponge.

Further preferably, the liquid phase in S6 is filtered, concentrated, oxidatively precipitated, calcined, and reduced with hydrogen to obtain sponge iridium.

Further preferably, the oxidative precipitation is carried out by adding hydrochloric acid, sodium sulfate and ammonium chloride to the concentrated iridium solution and stirring for precipitation.

More preferably, 18-22L of hydrochloric acid solution prepared in S3 is added into the organic phase of S6, and stirring is carried out for 4-6 minutes, so that the regeneration of tributyl phosphate is completed.

Preferably, the raffinate obtained from the S5 is subjected to 2-3-grade extraction according to the sequence of S4 and S5 until the content of iridium in the raffinate is detected to be at the lower limit of spectral analysis.

Further preferably, the rhodium-iridium solution in S1 does not contain noble metal cations.

Further preferably, the preparation of the rhodium-iridium solution in S1 comprises the following steps: a) dissolving aqua regia into a solution containing rhodium and iridium; b) controlling the acidity of the solution prepared in the step a) by nitrate removal, concentration and acid removal; c) exchanging with cation resin to remove base metal cations in the solution prepared in step b).

Has the advantages that: a rhodium iridium separation refining process adopts tributyl phosphate to extract high-valence iridium, the level-1 extraction reaches the required parameters, the reagent consumption is reduced, and the production flow is shortened; the content of rhodium and iridium in the separated finished product is more than 99.95 percent, the problem that the rhodium and iridium are not completely separated is solved,

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below.

Example 1:

a rhodium-iridium separation refining process comprises the following steps:

s1: preparing a rhodium-iridium solution to be separated, comprising the following steps: a) dissolving aqua regia into a solution containing rhodium and iridium; b) controlling the acidity of the solution prepared in the step a) by nitrate removal, concentration and acid removal; c) exchanging with cation resin to remove base metal cations in the solution prepared in step b). Then removing noble metal cations in the solution by methods such as repeated dissolution and precipitation, controlling the mass concentration of rhodium to be 50g/L and the hydrogen ion concentration to be 4mol/L, wherein the technology for preparing the rhodium-iridium solution belongs to the prior art and is not repeated herein;

s2: heating 20L of the rhodium-iridium solution prepared in the step S1 to 85 ℃, stopping heating, slowly adding 1000ml of hydrogen peroxide, stirring, uniformly stirring to fully oxidize the rhodium-iridium solution, and cooling for later use;

s3: preparing 4mol/l hydrochloric acid solution and 10% sodium hydroxide solution for later use;

s4: adding 20L of tributyl phosphate solution into a water-hydrogen high borosilicate glass separation kettle, adding 20L of hydrochloric acid solution prepared from S3, pre-balancing for 2 times, standing, discharging liquid phase, adding 1000ml of hydrogen peroxide, and stirring thoroughly for later use;

s5: mixing the solution treated by the S4 with the rhodium-iridium solution prepared by the S1, quickly stirring for 10 minutes, and discharging raffinate after standing, wherein the raffinate is the rhodium solution;

performing spectral analysis on the raffinate, and if the detected iridium content does not reach the spectral analysis lower limit, performing 2-3-level extraction on the raffinate according to S4 and S5 until the detected iridium content of the raffinate is at the spectral analysis lower limit; finally, collecting raffinate, reducing with formic acid, calcining and reducing with hydrogen to obtain sponge rhodium, wherein the technology for treating raffinate to obtain sponge rhodium belongs to the prior art and is not described herein again;

s6: and (3) backwashing the organic phase of S5 for 2-3 times by taking 10L of sodium hydroxide solution prepared in S3, discharging a liquid phase to be iridium solution, and then filtering, concentrating, oxidizing, precipitating, calcining and reducing by hydrogen to obtain the sponge iridium. Wherein, the oxidation precipitation is to add hydrochloric acid, sodium sulfate and ammonium chloride into the concentrated iridium solution and stir the mixture for precipitation.

In addition, 20L of hydrochloric acid solution prepared in S3 was added to the organic phase extracted in S6, and stirred for 5 minutes, thereby completing the regeneration of tributyl phosphate.

Example 2:

a rhodium-iridium separation refining process comprises the following steps:

s1: preparing a rhodium-iridium solution to be separated, comprising the following steps: a) dissolving aqua regia into a solution containing rhodium and iridium; b) controlling the acidity of the solution prepared in the step a) by nitrate removal, concentration and acid removal; c) exchanging with cation resin to remove base metal cations in the solution prepared in step b). Then removing noble metal cations in the solution by methods such as repeated dissolution and precipitation, controlling the mass concentration of rhodium to be 45g/L and the hydrogen ion concentration to be 3.5mol/L, wherein the technology for preparing the rhodium-iridium solution belongs to the prior art and is not repeated herein;

s2: heating 18L of the rhodium-iridium solution prepared in the step S1 to 80 ℃, stopping heating, slowly adding 800ml of hydrogen peroxide, stirring, uniformly stirring to fully oxidize the rhodium-iridium solution, and cooling for later use;

s3: preparing 3.5mol/l hydrochloric acid solution and 8% sodium hydroxide solution for later use;

s4: adding 18L of tributyl phosphate solution into a water-hydrogen high borosilicate glass separation kettle, adding 18L of hydrochloric acid solution prepared from S3, pre-balancing for 2 times, standing, discharging a liquid phase, adding 800ml of hydrogen peroxide, and fully stirring for later use;

s5: mixing the solution treated by the S4 with the rhodium-iridium solution prepared by the S1, quickly stirring for 8 minutes, and discharging raffinate after standing, wherein the raffinate is the rhodium solution;

performing spectral analysis on the raffinate, and if the detected iridium content does not reach the spectral analysis lower limit, performing 2-3-level extraction on the raffinate according to S4 and S5 until the detected iridium content of the raffinate is at the spectral analysis lower limit; finally, collecting raffinate, reducing with formic acid, calcining and reducing with hydrogen to obtain sponge rhodium, wherein the technology for treating raffinate to obtain sponge rhodium belongs to the prior art and is not described herein again;

s6: and (3) backwashing the organic phase of S5 for 2 times by taking 8L of sodium hydroxide solution prepared in S3, discharging a liquid phase which is an iridium solution, and then filtering, concentrating, oxidizing, precipitating, calcining and reducing by hydrogen to obtain the sponge iridium. Wherein, the oxidation precipitation is to add hydrochloric acid, sodium sulfate and ammonium chloride into the concentrated iridium solution and stir the mixture for precipitation.

In addition, 18L of hydrochloric acid solution prepared in S3 was added to the organic phase extracted in S6, and stirred for 4 minutes, thereby completing the regeneration of tributyl phosphate.

Example 3:

a rhodium-iridium separation refining process comprises the following steps:

s1: preparing a rhodium-iridium solution to be separated, comprising the following steps: a) dissolving aqua regia into a solution containing rhodium and iridium; b) controlling the acidity of the solution prepared in the step a) by nitrate removal, concentration and acid removal; c) exchanging with cation resin to remove base metal cations in the solution prepared in step b). Then removing noble metal cations in the solution by methods such as repeated negative electrode precipitation and the like, controlling the mass concentration of rhodium to be 55g/L and the hydrogen ion concentration to be 4.5mol/L, wherein the technology for preparing the rhodium-iridium solution belongs to the prior art and is not repeated herein;

s2: taking 22L of the rhodium-iridium solution prepared in the step S1, heating to 90 ℃, stopping heating, slowly adding 1200ml of hydrogen peroxide, stirring, uniformly stirring to fully oxidize the rhodium-iridium solution, and cooling for later use;

s3: preparing 4.5mol/l hydrochloric acid solution and 12% sodium hydroxide solution for later use;

s4: adding 22L of tributyl phosphate solution into a water-hydrogen high borosilicate glass separation kettle, adding 22L of hydrochloric acid solution prepared from S3, pre-balancing for 2 times, standing, discharging liquid phase, adding 1200ml of hydrogen peroxide, and stirring thoroughly for later use;

s5: mixing the solution treated by the S4 with the rhodium-iridium solution prepared by the S1, quickly stirring for 12 minutes, and discharging raffinate after standing, wherein the raffinate is the rhodium solution;

performing spectral analysis on the raffinate, and if the detected iridium content does not reach the spectral analysis lower limit, performing 2-3-level extraction on the raffinate according to S4 and S5 until the detected iridium content of the raffinate is at the spectral analysis lower limit; finally, collecting raffinate, reducing with hydrazine hydrate, calcining and reducing with hydrogen to obtain sponge rhodium, wherein the technology for treating raffinate to obtain sponge rhodium belongs to the prior art and is not repeated herein;

s6: and (3) backwashing the organic phase of S5 for 2-3 times by taking 12L of sodium hydroxide solution prepared in S3, discharging a liquid phase to be iridium solution, and then filtering, concentrating, oxidizing, precipitating, calcining and reducing by hydrogen to obtain the sponge iridium. Wherein, the oxidation precipitation is to add hydrochloric acid, sodium sulfate and ammonium chloride into the concentrated iridium solution and stir the mixture for precipitation.

In addition, 22L of hydrochloric acid solution prepared in S3 was added to the organic phase extracted in S6, and the mixture was stirred for 6 minutes, whereby the regeneration of tributyl phosphate was completed.

The rhodium-iridium solution is treated through the steps of the above embodiment, and finally finished rhodium powder with the content of more than 99.5% and sponge iridium powder with the content of more than 99.5% can be obtained.

The present invention is not limited to the above-mentioned preferred embodiments, and any other products in various forms can be obtained by anyone in the light of the present invention, but any changes in the shape or structure thereof, which have the same or similar technical solutions as those of the present application, fall within the protection scope of the present invention.