Separation And Enrichment Of Au(Ⅲ), Pd(Ⅱ) And Pt(Ⅳ) By Beryllon Ⅱ Forming Resin

A new chelate-forming resin bearing Beryllon Ⅱhas been prepared by stirring a solution of Beryllon Ⅱ with a macroporous strong basic anion exchange resin D290and the structure of the Beryllon II loaded resin was proved by means of infrared (IR) spectra. It can be used to separate and concentrate for the noble metal ions such as Au(Ⅲ), Pd(Ⅱ) and Pt(Ⅳ). Pt(Ⅳ) were determined with Oscillopolarography and Au(Ⅲ), Pd(Ⅱ) were determined with FAAS. The conditions on the static and dynamic adsorption and elution of noble metals have been studied. The adsorption isotherms and kinetics of the adsorption behavior of resin for Au(Ⅲ), Pd(Ⅱ) and Pt(Ⅳ) have been investigated. Furthermore, the stability and regeneration properties of this forming resin with Beryllon Ⅱ have been studied. Additionally, the geological standard sample analysis has been carried out to check up the feasibility of the method.Various parameters such as pH, temperature, initial concentration of Au(Ⅲ), Pd(Ⅱ) and Pt(Ⅳ) and contact time have been investigated by batch test; flow rate of sample solution, amounts of resins have been investigated by dynamic test; eluent type, volume, elution time, temperature and flow rate of eluent have been studied. The optimum adsorption pH values of Au(Ⅲ), Pd(Ⅱ) and Pt(Ⅳ) onto Beryllon Ⅱ Forming Resin are5.00,2.00and2.00, respectively. Adsorption capacities of Beryllon Ⅱ Forming Resin for Au(Ⅲ), Pd(Ⅱ) and Pt(Ⅳ) increase with the increases of contact time and initial concentrations of noble metal ions; temperature has little effect on the adsorption capacities. When the temperature is25℃and pH (HC1) is respective optimum pH,20.00mL250.0mg·L-1Au(Ⅲ),50.00mg·L-1Pd(Ⅱ) and120.0mg·L-1Pt(Ⅳ) are adsorbed to equilibrium by0.0050g Beryllon II Formation Resin for8h,5h, and6h, respectively. In dynamic adsorption experiments for Au(Ⅲ), Pd(Ⅱ) and Pt(Ⅳ), adsorption rates of Beryllon Ⅱ Forming Resin increase with the increase of the amounts of resins and decrease with the increase of flow rates. When the pH (HC1) is respective optimum pH, the flow rate of sample solution is0.30mL/min and the amount of resin is0.1000g, adsorption rate of noble metal ions are all above95%. When the temperature is25℃, elution with pH2.00HC1and3%thiourea (10.00mL) for60min by batch method or elution by this eluent (20.00mL) with the velocity of flow at0.30mL per minute by dynamic method, elution rates of Au(III), Pd(Ⅱ) and Pt(Ⅳ) are all above95%. According to experimental results, Beryllon Ⅱ Forming Resin have higher adsoption capacities for noble metal ions, and the stability and regeneration properties of this resin are good.Langmuir and Freundlich equation are applied to analyze the relevant experimental data. The isothermal adsorption of Beryllon II Forming Resin obey Langmuir equation for the adsorption of Au(Ⅲ), Pd(Ⅱ) and Pt(Ⅳ), indicating that the adsorption is a monolayer one.The adsorption kinetics data are fitted with pseudo-first-order kinetic equation, pseudo-second-order kinetic equation, Boyd’s diffusion equation of liquid film and intraparticle diffusion model. The results show the adsorption kinetics follow a pseudo-second-order model for the adsorption of Au(III), Pd(Ⅱ) and Pt(Ⅳ) by Beryllon Ⅱ Forming Resin and that the adsorption of this resin is controlled by liquid film diffusion in case of Au(Ⅲ) and Pt(Ⅳ) and by intraparticle diffusion in case of Pd(Ⅱ).The results obtained by the analysis of geological standard samples show the relative standard deviation (n=6) values are3.1%and2.4%for Au(Ⅲ),5.5%and4.1%for Pd(Ⅱ) and2.7%and3.7%for Pt(Ⅳ) and that the values of tcalculated are all less than Ttable(0.05)=2.57. The limits of detections of Au(Ⅲ), Pd(Ⅱ) and Pt(Ⅳ) are0.011mg/L,0.016mg/L and4.17×10-6mg/L, respectively.The main advantages of this method are its simplicity, high speed and precision. It is proved to be practical and efficient by practice.