Method for adsorbing rhodium and iridium by using phosphorus-containing polymer adsorption resin

Abstract

The invention discloses a method for adsorbing rhodium and iridium by using phosphorus-containing polymer adsorption resin, and particularly relates to a method for enriching rhodium and iridium before purifying rhodium and iridium from precious metal enriched concentrate, which comprises the following three steps: preparing phosphorus-containing porous polymer adsorption resin, selectively adsorbing rhodium and iridium, and desorbing and recycling to realize rhodium and iridium adsorption. Subsequent purification of rhodium and iridium is facilitated. Compared with traditional resin adsorption, the phosphorus-containing high-molecular adsorption resin is a functionalized high-molecular material, combines the characteristics of traditional adsorption resin and the advantages of phosphorus-containing compounds, and has pertinence and high efficiency in the aspect of rhodium and iridium metal adsorption. The rhodium and the iridium are rare and expensive metals, so that the two noble metals are recovered through the adsorption effect of the phosphorus-containing polymer, and the method has important significance on efficient utilization of secondary resources and maximization of economic benefits.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precious metal refining, and relates to a method for adsorbing rhodium and iridium by using phosphorus-containing high polymer adsorption resin. BACKGROUND

[0002] Precious metals are valued in the fields of science and technology and industry such as electronics, aerospace, etc. due to their intrinsic value and unique physical and chemical properties. Rhodium and iridium are two very rare and unique precious metals with physical and chemical properties, which exist in platinum ore and are usually extracted in the refining process. Rhodium and iridium play an indispensable role in the fields of basic science, energy application and industrial application. However, we face great challenges in the process of extracting and refining rhodium and iridium, including limited availability, high production cost and complex recovery process. The phosphorus-containing high polymer adsorption resin as an advanced functional material is of great importance to the sustainable supply of precious resources such as rhodium and iridium, the improvement of recovery technology and the optimization of resource management. SUMMARY

[0003] Based on the above, the purpose of the present application is to provide a method for adsorbing rhodium and iridium by using phosphorus-containing high polymer adsorption resin, which has a simple process flow, is easy to operate, has high processing efficiency, is of great significance to the maximum recovery of rhodium and iridium, and can effectively reduce the loss of rhodium and iridium.

[0004] To achieve the purpose, the present application adopts the following technical scheme: A method for adsorbing rhodium and iridium by using phosphorus-containing high polymer adsorption resin, comprising the following steps: (1) Preparation of phosphorus-containing high polymer adsorption resin: carbonizing phosphorus-containing high polymer material at 750-850°C to obtain phosphorus-containing material with a porous structure, and then activating the phosphorus-containing material by water vapor to obtain the phosphorus-containing high polymer adsorption resin, which has a porous structure and can adsorb rhodium and iridium; (2) Selective adsorption of rhodium and iridium: control the valence of rhodium and iridium in the pre-adsorption solution to be +3 by existing process, and the specific operation is as follows: first dissolve the rhodium and iridium-containing raw material in 6 mol / L hydrochloric acid solution, stir at 300 rpm and 60°C for 30 min to form a stable chloro complex, then add sodium bisulfite (NaHSO3) in batches, adjust the pH to about 1, and continue to stir at 60°C for 60 min to reduce the rhodium and iridium in the solution to +3 valence; after the treatment is completed, excess SO2 is removed by air, and the solution is adjusted to pH=1.0 and temperature 55°C to obtain a stable solution mainly containing Rh 3+ and [IrCl6] 3- as the main component, which meets the conditions of the subsequent resin selective adsorption of the inlet solution, i.e. the pre-adsorption solution; Add an alkaline solution to the pre-adsorption solution to control the pH to 1-1.5 and the temperature of the pre-adsorption solution to 55-80℃. Add the phosphorus-containing polymer adsorption resin described in (1). Due to the porous nature of the resin and the presence of phosphorus-containing groups, it can selectively adsorb metals. Adsorb for 6-8 hours under stirring to ensure sufficient contact time and obtain resin material adsorbed with rhodium and iridium. The adsorption rate of rhodium and iridium can be calculated by measuring the change in the concentration of metal ions in the solution before and after adsorption. (3) Desorption and recycling: The resin material adsorbed with rhodium and iridium in (2) is placed in an alkaline liquid with pH 9~12 and stirred at 60~80℃ for 4~8 hours. After filtration, a desorption solution is obtained. Chlorine gas is introduced into the desorption solution until pH=7~8 to obtain rhodium and iridium precipitate. The desorbed resin is regenerated by heating to above 80℃ to remove pollutants on the resin and restore its adsorption performance for recycling.

[0005] As a further preferred embodiment of the technical solution of the present invention, in step (1), the polymer material is a synthetic resin or a biomass material containing phosphoric acid groups after phosphoric acid treatment.

[0006] Further, in step (1), the synthetic resin is an aminophosphate resin (molecular formula (C6H42- ... 10 NO3P) X (The structural formula is R-NH-PO3H2).

[0007] Furthermore, in step (1), the carbonization time is 2-5 hours.

[0008] Further, in step (2), the alkaline solution is a sodium hydroxide solution with a mass fraction of 40%.

[0009] Furthermore, in step (2), the amount of phosphorus-containing polymer adsorption resin added is 2 to 5 times the mass of rhodium and iridium.

[0010] In summary, when adsorbing rhodium and iridium, it is crucial to carefully control adsorption conditions, such as solution temperature and contact time, as these factors can affect adsorption efficiency and selectivity. Furthermore, to evaluate the adsorption effect, the change in metal ion concentration in the solution before and after adsorption is typically measured, and the removal rate and adsorption capacity are calculated. By optimizing these steps and parameters, the efficiency and cost-effectiveness of phosphorus-containing polymer adsorption resins in adsorbing precious metals can be improved.

[0011] Compared with existing conventional resin adsorption technology, the present invention has the following advantages: 1. The method of the present invention is easy to operate and is 6-8 hours faster than the two-stage adsorption of rhodium and iridium by ordinary resin, with high processing efficiency; 2. After carbonization, the phosphorus-containing polymer material of this invention exhibits a unique affinity between its phosphorus groups and rhodium and iridium metals, enabling selective adsorption of rhodium and iridium. This means that in the presence of multiple noble metals, the phosphorus-containing polymer can more effectively separate the target metal, thereby improving the selectivity of the adsorption process. 3. The method of this invention enhances the adsorption efficiency for rhodium and iridium: Traditional adsorption resins cannot be used in organic solvent systems under certain circumstances, while the phosphorus-containing polymeric adsorption resin of this invention overcomes this limitation. Furthermore, the phosphorus-containing polymeric adsorption resin of this invention can reduce the metal content in waste liquid to very low levels (e.g., rhodium and iridium content from 1 to 10,000 ppm to below 1 ppm), exhibiting higher adsorption efficiency; 4. The phosphorus-containing polymer materials described in this invention have excellent chemical properties (such as high temperature resistance and ion exchange capacity), which enable them to work in a wider range of pH values ​​and temperatures, providing more possibilities for adsorption under different conditions. 5. Compared with traditional rhodium and iridium recovery processes such as incineration, the adsorption method of this invention uses phosphorus-containing polymer adsorption resin, which can reduce environmental pollution, improve recovery efficiency, and avoid waste of resources. Detailed Implementation

[0012] The present invention will be further described below with reference to specific embodiments. The listed embodiments are only a part of them, and their purpose is to provide a more detailed description of the present invention and verify its effects.

[0013] In the following examples, the phosphorus-containing polymer material is an aminophosphate resin, and the preparation method of the phosphorus-containing polymer adsorption resin is as follows: Aminophosphoric acid resin was carbonized at 750℃ for 3 hours to prepare a phosphorus-containing material with a porous structure. Then, it was activated with water vapor to obtain a phosphorus-containing polymer adsorption resin that can adsorb rhodium and iridium.

[0014] Example 1 The pre-adsorption solution from a platinum group metals production company was tested, and the contents of Rh and Ir were found to be 0.18 g / L and 0.15 g / L, respectively. In the experiment, 500 mL of the pre-adsorption solution was taken and concentrated to 200 mL by heating in a container. Water was then added to bring the total volume to 300 mL, and a 40% sodium hydroxide solution was added to adjust the pH to 1.5. After heating to 60°C, 50 g of the prepared phosphorus-containing polymer adsorption resin was added. The mixture was stirred at 300 rpm for 6 hours, allowed to stand for 30 minutes, and then solid-liquid separation was performed using a filtration device to obtain the resin material that adsorbed rhodium and iridium. The concentrations of rhodium and iridium metal ions in the solution before and after adsorption were measured to be 0.01 g / L and 0.01 g / L, respectively, indicating a rhodium-iridium adsorption rate of 95%. The resin material adsorbed with rhodium and iridium was washed with sodium hydroxide solution at pH=10, heated to 75℃, stirred at 300 rpm for 6 hours, and then filtered. The concentrations of rhodium and iridium metal ions in the filtrate were measured to be 0.16 g / L and 0.13 g / L, respectively, indicating a rhodium-iridium desorption rate of 94%. Chlorine gas was then introduced until the pH reached 7, and the rhodium-iridium precipitate was obtained for separation and refining of rhodium and iridium.

[0015] Example 2 The pre-adsorption solution from a platinum group metals production company was tested, and the contents of Rh and Ir were found to be 0.23 g / L and 0.18 g / L, respectively. In the experiment, 1600 ml of the pre-adsorption solution was pumped into an enamel-lined autoclave, concentrated to 600 mL by steam, and then purified water was added to bring the volume to 1200 ml. A 40% sodium hydroxide solution was added to adjust the pH to 1.5. The mixture was heated to 65°C by steam, and then 60 g of the prepared phosphorus-containing polymer adsorption resin was added. After stirring at 300 rpm for 8 hours, the mixture was filtered to obtain a resin material that adsorbed rhodium and iridium. The concentrations of rhodium and iridium metal ions in the solution before and after adsorption were measured to be 0.02 g / L and 0.01 g / L, respectively, indicating a rhodium-iridium adsorption rate of 92%. The resin material adsorbed with rhodium and iridium was washed with sodium hydroxide solution at pH=10, heated to 80℃, stirred at 300 rpm for 5 hours, allowed to stand for 30 minutes, filtered, and the concentrations of rhodium and iridium metal ions in the filtrate were measured to be 0.20 g / L and 0.16 g / L, respectively, indicating that the rhodium-iridium desorption rate could reach over 95%.

Claims

1. A method for adsorbing rhodium and iridium using a phosphorus-containing polymer adsorption resin, characterized in that, Includes the following steps: (1) Preparation of phosphorus-containing polymer adsorption resin: The phosphorus-containing polymer material is carbonized at 750℃~850℃ to obtain a phosphorus-containing material with a porous structure. Then, the phosphorus-containing material is activated with water vapor to obtain the phosphorus-containing polymer adsorption resin. (2) Selective adsorption of rhodium and iridium: control the rhodium and iridium in the pre-adsorption solution to be +3 valence, add alkaline solution, control the pH to be 1~1.5, control the temperature of the pre-adsorption solution to be 55~80℃, add the phosphorus-containing polymer adsorption resin described in (1), and adsorb for 6~8 hours under stirring to obtain resin material adsorbed with rhodium and iridium. (3) Desorption and recycling: The resin material adsorbed with rhodium and iridium in (2) is placed in an alkaline liquid with pH 9~12, stirred at 60~80℃ for 4~8 hours, filtered, and the desorbed liquid is obtained. Chlorine gas is introduced into the desorption solution to bring the pH to 7-8, resulting in a rhodium-iridium precipitate. The desorbed resin is then regenerated by heating to above 80°C to remove impurities before recycling.

2. The method for adsorbing rhodium and iridium using a phosphorus-containing polymer adsorption resin as described in claim 1, characterized in that, In step (1), the polymer material is a synthetic resin or a biomass material containing phosphoric acid groups after phosphoric acid treatment.

3. The method for adsorbing rhodium and iridium using a phosphorus-containing polymer adsorption resin as described in claim 2, characterized in that, In step (1), the synthetic resin is an aminophosphate resin (molecular formula (C6H42- ... 10 NO3P) X (The structural formula is R-NH-PO3H2).

4. The method for adsorbing rhodium and iridium using a phosphorus-containing polymer adsorption resin as described in claim 3, characterized in that, In step (1), the carbonization time is 2-5 hours.

5. The method for adsorbing rhodium and iridium using a phosphorus-containing polymer adsorption resin as described in claim 1, characterized in that, In step (2), the alkaline solution is a sodium hydroxide solution with a mass fraction of 40%.

6. The method for adsorbing rhodium and iridium using a phosphorus-containing polymer adsorption resin as described in claim 5, characterized in that, In step (2), the amount of phosphorus-containing polymer adsorption resin added is 2 to 5 times the mass of rhodium and iridium.