Method for adsorbing platinum in waste catalyst lixivium through ultrasonic reinforced resin

Abstract

The invention relates to a method for adsorbing platinum in a waste catalyst leaching solution through ultrasonic enhanced resin, and belongs to the technical field of recovery of precious metals from waste catalysts, the platinum-containing leaching solution obtained after chlorination leaching of a platinum-containing waste catalyst under a hydrochloric acid system is used as a raw material, and the method comprises the following steps: step one, preparing a raw material; the method comprises the following steps: pretreating strongly basic anion exchange resin with hydrochloric acid and sodium hydroxide to obtain resin of which adsorbed ions are hydroxyl; 2, the pretreated resin is put into the leachate for ultrasonic enhanced adsorption, and platinum-adsorbed resin is obtained; step 3, separating the platinum-adsorbed resin from the leachate by using a vacuum pump and a suction flask; and 4, desorbing the resin by using a desorption agent such as perchloric acid and the like to obtain a purified platinum-containing solution. According to the method, in the process of adsorbing the platinum-containing leachate through the ultrasonic-enhanced resin, as the leachate is of a hydrochloric acid system, the platinum in the leachate is adsorbed through the strongly basic anion resin, the platinum-complex waste catalyst leachate is separated and purified, and the adsorption rate and adsorption rate of the resin are improved through ultrasonic enhancement.

Description

Technical Field

[0001] The invention belongs to the technical field of recovering precious metals from waste catalysts, and in particular relates to a method for ultrasonically enhancing the absorption of platinum in waste catalyst leaching solution by resin. Background Art

[0002] Platinum is a rare and precious element located in the transition zone between sulfur-loving and nitrogen-loving elements, often coexisting with other platinum group metals. With increasing demand for platinum and its expanded uses, platinum consumption has shown a gradual upward trend, and the supply-demand imbalance has become increasingly prominent. Therefore, the comprehensive utilization of secondary platinum group resources is of great significance. Platinum has the widest and most extensive application among the platinum group metals. Due to its excellent catalytic properties and stability, platinum is primarily used in automotive exhaust catalytic purification, chemical and petrochemical catalysts, platinum jewelry, glass fiber industry bushings and crucibles, medical drugs, and dental care. Currently, the most widely used catalysts are in automotive exhaust purification and petrochemical industries. Due to their large usage, concentrated distribution, and ease of collection, spent catalysts are the largest source of recycled secondary platinum group resources. Accumulation of spent catalysts not only wastes resources but also pollutes the environment. Therefore, research on the recovery of platinum from catalysts is crucial.

[0003] The content of precious metal platinum in the catalyst is very small. Common recovery methods include leaching and fire recovery. Fire recovery includes smelting, volatilization, incineration and other methods. Since platinum is widely distributed on the surface of the carrier in the form of dispersed metal particles, it is easy to dissolve by aqueous solution chlorination. Therefore, leaching is the preferred option. After leaching, platinum is converted into [Pt] 4+ and [Pt] 2+ It exists in the form of other base metal ions and chloride ions. It is difficult for other base metal ions to form complexes with chloride ions, but platinum can form a stable complex with chloride ions [PtCl6] 2- . There are mainly reduction method, replacement method and precipitation method for treating platinum-containing solutions. The reduction method uses reducing agents such as hydrazine hydrate (N2H4) to reduce platinum group elements to achieve the separation effect, but there is a problem that the reduction is not complete when the pH value is low, and the base metals are also reduced when the pH value is high. The replacement method is to achieve the enrichment effect by replacing precious metals with active metals. Its advantages are rapid process, simple equipment, and high precious metal recovery, but there are problems such as the need to consume a large amount of active metals and high cost. The precipitation method uses thiourea and precious metal chloride complexes to form various complexes, which are heated in a concentrated sulfuric acid medium to form a sulfide precipitate, while other base metals do not react, thereby achieving the separation effect. Its advantage is that it has a good separation effect, but when the precious metal content is low, a carrier needs to be added to achieve the separation effect. The sulfidation method achieves the purpose of separation by generating a sulfide precipitate and then using sulfuric acid and the like to dissolve base metal impurities, but there is a problem that the sulfide precipitate is too fine, and solid-liquid separation is difficult when the quantity is large. Summary of the Invention

[0004] To overcome the problems existing in the background technology, the present invention provides a method for ultrasonically enhanced resin adsorption of platinum in a waste catalyst leachate. The method achieves the recovery of platinum from a platinum-containing hydrochloric acid leachate using a simple method, and has fast adsorption and desorption rates, a high platinum recovery rate, pure platinum recovery, and easy control of operating indicators.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions:

[0006] The method for ultrasonically enhancing the resin adsorption of platinum in the waste catalyst leachate comprises the following steps:

[0007] (1) Treatment of 717 strong base anion resin;

[0008] (2) placing the pretreated resin in a platinum-containing leaching solution for ultrasonic enhanced adsorption to obtain a platinum-adsorbed resin;

[0009] (3) separating the platinum-adsorbed resin from the leachate;

[0010] (4) Desorbing the resin with a desorbent under ultrasonic conditions to obtain a purified platinum-containing solution.

[0011] Furthermore, the leaching solution in step (2) is a platinum-containing leaching solution leached in a hydrochloric acid system.

[0012] Furthermore, the adsorption time of step (2) is 3 h, and the ultrasonic power is 50-500 W.

[0013] Furthermore, the liquid-to-solid ratio of the resin to the platinum-containing leachate in step (2) is 1 L of platinum-containing solution / 5-10 g of resin, and the concentration of platinum in the platinum-containing solution is 100 mg-300 mg / L.

[0014] Furthermore, the desorbent in step (3) is perchloric acid.

[0015] Furthermore, the desorption temperature of step (4) is 20-30° C., the ultrasonic power is 50-500 W, and the desorption time is 3 h.

[0016] Furthermore, the resin after desorption in step (4) is treated and recycled, and the treatment method is as follows: first, soak the resin in saturated salt water, the amount of salt water used is 2-3 times the volume of the resin, after soaking, drain the salt water, and wash with clean water; soak the resin in a hydrochloric acid solution with a concentration of not more than 10%, the amount of hydrochloric acid used is 2-3 times the volume of the resin, stir it thoroughly and let it stand, drain the hydrochloric acid solution, and wash with clean water until the resin is neutral; soak the resin in a NaOH solution with a concentration of not more than 10%, stir it thoroughly and let it stand to obtain the pretreated 717 strong alkaline anion resin of step (1).

[0017] Beneficial effects of the present invention:

[0018] The present invention adopts 717 strong basic anion resin, and after pre-treating the 717 strong basic anion resin, adsorbs and desorbs platinum in a platinum-containing leachate under ultrasonic conditions, which can greatly shorten the adsorption and desorption time of platinum, and the adsorption rate is as high as 98.83%, and the desorption rate is as high as 97.75%. The desorbed resin can be recycled after pre-treatment.

[0019] The method of the invention separates and purifies platinum from the chlorination system leachate, thus meeting the requirements of further purification and refining; the remaining leachate residue is an aluminum chloride solution, which can be further recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a simplified process flow diagram of the present invention;

[0021] Figure 2 is the isothermal adsorption-desorption curve before resin adsorption of Example 1 of the present invention;

[0022] Figure 3 Isothermal adsorption-desorption curve after resin adsorption of Example 1 of the present invention

[0023] Figure 4 is the isothermal adsorption-desorption curve after desorption of the resin of Example 1 of the present invention;

[0024] Figure 5 These are resin morphology diagrams at different stages of Example 1 of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and beneficial effects of the present invention more clear, the technical solution of the present invention will be described in detail below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0026] In order to illustrate the present invention more clearly, the following examples are provided for detailed description.

[0027] Resin pretreatment (the following resins are all pretreated using this method)

[0028] Add 2-3 times the volume of saturated salt water to 717 strong alkaline anion resin, stir thoroughly, let it stand for 5 hours, drain the salt water, and rinse with clean water; soak the resin with 5% hydrochloric acid solution, the amount of which is 2-3 times the volume of the resin, stir thoroughly, and let it stand.

[0029] Drain the hydrochloric acid solution and wash with clean water until the resin is neutral; soak the resin with 5% NaOH solution, stir it thoroughly and let it stand for 8 hours to remove impurities in the resin to obtain hydroxide-type resin.

[0030] Example 1

[0031] The leaching liquid of platinum-containing waste catalyst from a domestic factory was taken, and the main element contents were: Al 6.72g / L, Pt 0.163g / L, Cl48.9g / L, K 0.556g / L, S 0.011g / L, and Si 0.5g / L.

[0032] According to the solid-liquid ratio of hydroxide resin to platinum-containing waste catalyst leachate of 0.7g / 100ml, the pretreated resin and leachate were placed in a water bath ultrasonic equipment for experiment. The ultrasonic power was 360W, the stirring speed was 700r / min, the adsorption temperature was 25℃, the adsorption time was 3h, the pH value was 1. After the adsorption was completed, the resin was filtered and separated to obtain the platinum-adsorbed resin. The platinum content in the platinum-containing leachate after adsorption was 0.003g / L.

[0033] The platinum-adsorbed resin was then desorbed using 2 mol / L perchloric acid under ultrasonic conditions at 240 W, a temperature of 25°C, and a desorption time of 3 hours. This resulted in a purified platinum solution with a platinum content of 0.159 g / L.

[0034] Adsorption rate (E%) and solid-liquid partition coefficient (K d ) is an important parameter for evaluating the adsorption effect.

[0035]

[0036]

[0037] Where: C0 is the initial concentration of metal ions in the solution, mg / L; Ce is the equilibrium concentration of metal ions in the solution, mg / L; V is the volume of the solution, mL; m is the weight of the resin, g.

[0038] According to the analysis of formula (1), the platinum adsorption rate is 98.83% and the desorption rate is 97.75%. The desorbed resin is recycled after pretreatment.

[0039] The isothermal adsorption-desorption curves and pore size distribution diagrams before, after and after resin adsorption were analyzed using a fully automatic specific surface area and porosity analyzer (BET). Figure 2 This is the isothermal adsorption-desorption curve before resin adsorption. It can be seen that the adsorption capacity steadily increases during the adsorption process, while the desorption curve exhibits a hysteresis loop, which is caused by weak gas-solid interactions within the mesoporous solid. The curves in the figure are not closed and cross, possibly due to the resin's low specific surface area and small number of pores. Figure 3The isothermal adsorption-desorption curve after resin adsorption is not much different from that before adsorption. The specific surface area and average pore size are reduced after adsorption. This is because [PtCl6] 2- This is caused by ions filling the pores, which confirms the reliability of the resin adsorbing platinum. Figure 4 This is the image after resin desorption. Compared to before adsorption, the average pore size and total pore volume of the resin are slightly smaller, likely due to some pore collapse and shrinkage after use. However, the specific surface area remains similar, which is related to the effect of ultrasound. This indicates that platinum has been successfully desorbed from the resin. The resin still has sufficient specific surface area and space for repeated adsorption. This also indirectly demonstrates that the resin can be reused, reducing production costs.

[0040] Figure 5 These are scanning electron microscope micrographs of the resin before, after, and after desorption. Under the action of ultrasound, a few scratches appear on the resin surface, but no obvious broken or broken gaps are seen, indicating that ultrasound does not cause great damage to the resin itself when it plays a strengthening role, which is conducive to the reuse of the resin. Figure 5 In the figure, a1 is the pre-treated resin magnified 40 times; a2 is the pre-treated resin magnified 100 times; b1 is the adsorption resin magnified 40 times; b2 is the adsorption resin magnified 100 times; c1 is the resin after desorption magnified 40 times; c2 is the resin after desorption magnified 100 times.

[0041] When the resin was subjected to elemental analysis, the platinum content of the resin after adsorption was significantly increased compared with the initial resin, and the platinum content of the resin after desorption was significantly decreased compared with the adsorbed resin, which was consistent with the measured experimental data and also reflected the adsorption and desorption effects of the resin.

[0042] Comparative Example 1

[0043] A platinum-containing leachate from a domestic waste catalyst plant was collected. The main element contents (g / L) were: Al 6.72g / L, Pt 0.163g / L, Cl 48.9g / L, K 0.556g / L, S 0.011g / L, and Si 0.5g / L. After resin pretreatment, the resin and leachate were placed in a constant-temperature magnetic stirring water bath for an adsorption time of 3 hours, a liquid-to-solid ratio, and a pH of 1. The stirring speed was 700 rpm. After the experiment, the resin was filtered and separated to obtain the platinum-adsorbed resin. The platinum-adsorbed resin was then desorbed using perchloric acid under standard conditions to obtain a purified platinum-containing solution and resin. The pretreated resin can be reused. The resulting resin has an adsorption efficiency of 85.35% and a desorption efficiency of 80.53%.

[0044] Example 2

[0045] A platinum-containing waste catalyst leachate from a domestic factory was obtained. The main element contents were (g / L): Al 6.72 g / L, Pt 0.163 g / L, Cl 48.9 g / L, K 0.556 g / L, S 0.011 g / L, and Si 0.5 g / L. The resin pretreated after desorption in Example 1 was used for adsorption at a solid-to-liquid ratio of resin to leachate (unless otherwise specified below, the liquid-to-solid ratio refers to the liquid-to-solid ratio of resin to leachate) of 0.7 g / 100 ml. The adsorption time was 3 h and the pH was 4. The resin and leachate were placed in a water bath ultrasonic apparatus with an ultrasonic power of 360 W, a stirring speed of 700 r / min, and a water bath temperature of 25°C. After the experiment, the resin was filtered and separated to obtain a platinum-adsorbed resin. The platinum-containing waste catalyst leachate after adsorption contained 0.01 g / L of platinum.

[0046] The platinum-adsorbed resin was then desorbed using perchloric acid under ultrasonic conditions at 360W for 3 hours, yielding a purified platinum solution with a platinum content of 0.142g / L. Analysis revealed a platinum adsorption rate of 95.89% and a desorption rate of 92.78%. The desorbed resin was then pretreated and recycled.

[0047] Example 3

[0048] A platinum-containing waste catalyst leachate from a domestic plant was collected. The main element contents (g / L) were: Al 6.72g / L, Pt 0.163g / L, Cl 48.9g / L, K 0.556g / L, S 0.011g / L, and Si 0.5g / L. After resin pretreatment, the resin and leachate were placed in a water bath ultrasonic bath for an adsorption time of 5 hours, a solid-to-liquid ratio of 0.7g / 100ml, and a pH of 1. The ultrasonic power was 360W and the stirring speed was 700r / min. After the experiment, the resin was filtered and separated to obtain the platinum-adsorbed resin. The platinum-adsorbed resin was then desorbed using perchloric acid under ultrasonic conditions to obtain a purified platinum-containing solution and resin. The pretreated resin can be reused. The resulting resin has an adsorption efficiency of 97.43% and a desorption efficiency of 95.76%.

[0049] Example 4

[0050] A platinum-containing leachate from a domestic waste catalyst plant was collected. The main element contents (g / L) were: Al 6.72g / L, Pt 0.163g / L, Cl 48.9g / L, K 0.556g / L, S 0.011g / L, and Si 0.5g / L. After resin pretreatment, the resin and leachate were placed in a water bath ultrasonic bath for an adsorption time of 3 hours, a solid-to-liquid ratio of 0.7g / 100ml, and a pH of 1. The ultrasonic power was 120W and the stirring speed was 700r / min. After the experiment, the resin was filtered and separated to obtain the platinum-adsorbed resin. The platinum-adsorbed resin was then desorbed using perchloric acid under ultrasonic conditions to obtain a purified platinum-containing solution and resin. The pretreated resin can be reused. The resulting resin has an adsorption efficiency of 73.8% and a desorption efficiency of 70.56%.

[0051] Example 5 (liquid-to-solid ratio 0.3 g resin / 100 ml platinum-containing solution)

[0052] A platinum-containing waste catalyst leachate from a domestic plant was collected. The main element contents (g / L) were: Al 6.72g / L, Pt 0.163g / L, Cl 48.9g / L, K 0.556g / L, S 0.011g / L, and Si 0.5g / L. After resin pretreatment, the resin and leachate were placed in a water bath ultrasonic bath for an adsorption time of 3 hours, a solid-to-liquid ratio of 0.3g / 100ml, and a pH of 1. The experiment was conducted at an ultrasonic power of 360W and a stirring speed of 700r / min. After the experiment, the resin was filtered and separated to obtain the platinum-adsorbed resin. The platinum-adsorbed resin was then desorbed using perchloric acid under ultrasonic conditions to obtain a purified platinum-containing solution and resin. The pretreated resin can be reused. The resulting resin has an adsorption efficiency of 91.72% and a desorption efficiency of 90.47%.

[0053] Comparative Example 2

[0054] This embodiment differs from Example 1 in that D201 anion exchange resin was used. A platinum-containing waste catalyst leachate from a domestic plant was prepared. The main element contents (g / L) were: Al 6.72 g / L, Pt 0.163 g / L, Cl 48.9 g / L, K 0.556 g / L, S 0.011 g / L, and Si 0.5 g / L. After resin pretreatment, the resin and leachate were placed in a water bath ultrasonic apparatus for an adsorption time of 3 h, a solid-to-liquid ratio of 0.7 g / 100 ml, and a pH of 1. The experiment was conducted at a stirring speed of 700 r / min. After the experiment, the resin was filtered and separated to obtain a platinum-adsorbed resin. The platinum-adsorbed resin was then desorbed using perchloric acid under conventional conditions to obtain a separated and purified platinum-containing solution and resin. The pretreated resin can be reused. The resulting resin had an adsorption rate of 82.94% and a desorption rate of 80.53%.

[0055] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for ultrasonically enhancing the adsorption of platinum in waste catalyst leachate by resin, characterized in that: The following steps are involved: (1) Treatment of 717 strong base anion resin; (2) placing the pretreated resin into a platinum-containing leaching solution for ultrasonic enhanced adsorption to obtain a platinum-adsorbed resin; (3) Separating the platinum-adsorbed resin from the leachate; (4) The resin is desorbed with a desorbent under ultrasonic conditions to obtain a purified platinum-containing solution.

2. The method according to claim 1, characterized in that The leaching solution described in step (2) is a platinum-containing leaching solution leached in a hydrochloric acid system.

3. The method according to claim 1, characterized in that The adsorption time of step (2) is 3 h, and the ultrasonic power is 50-500 W.

4. The method according to claim 1, wherein The liquid-to-solid ratio of the resin to the platinum-containing leaching solution in step (2) is 1 L of platinum-containing solution / 5-10 g of resin, and the concentration of platinum in the platinum-containing solution is 100 mg-300 mg / L.

5. The method according to claim 1, wherein The desorbent in step (3) is perchloric acid.

6. The method according to claim 1, characterized in that The desorption temperature of step (4) is 20-30°C, the ultrasonic power is 50-500W, and the desorption time is 3h.

7. The method for adsorbing platinum in waste catalyst leachate by using an ultrasonically enhanced resin according to claim 1, wherein: The resin after desorption in step (4) is treated and recycled, and the treatment method is as follows: first, soak the resin in saturated salt water, the amount of salt water used is 2-3 times the volume of the resin, after soaking, drain the salt water, and wash with clean water; soak the resin in a hydrochloric acid solution with a concentration not exceeding 10%, the amount of hydrochloric acid used is 2-3 times the volume of the resin, stir it thoroughly and let it stand, drain the hydrochloric acid solution, and wash with clean water until the resin is neutral; soak the resin in a NaOH solution with a concentration not exceeding 10%, stir it thoroughly and let it stand to obtain the pretreated 717 strong alkaline anion resin of step (1).

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