CN−的吸附行為及機理
(西安建筑科技大學 貴金屬工程研究所，西安 710055)
摘 要: 研究鐵氰溶液中D301樹脂對Fe(Ⅲ)及CN−的吸附性能及過程的動力學和熱力學參數(shù)。結果表明：25 ℃時，D301樹脂(濕樹脂)對Fe(Ⅲ)及CN−的飽和吸附量分別為2.173 49 mg/mL和28.963 2 mg/mL。吸附過程符合Lagergren二級速度方程，以液膜擴散為主控步驟。樹脂對Fe(Ⅲ)及CN−的吸附速率方程分別為：t/Qt=0.057 1 t+2.415和t/Qt=0.427 9 t+4.572 1，吸附速率常數(shù)分別為k2=1.35 mL/(g∙min)和k2=39.9 mL/(g∙min)。熱力學研究表明，吸附過程的焓變分別為： =16.78 J/mol， =11.07 J/mol，表明吸附過程是吸熱過程。
關鍵字: 樹脂；吸附；動力學；熱力學
Fe(Ⅲ) and CN− in iron-cyanide solution
（Institute of Precious Metal Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China）
Abstract:The sorption properties of D301 resin for Fe(Ⅲ) and CN− were studied as well as dynamic parameter and thermodynamic parameter in the process. The static saturated adsorptive capacity of D301 resin on Fe(Ⅲ) and CN− is 2.173 49 mg/mL and 28.963 2 mg/mL, respectively, at 25 ℃. The sorption process accords with Lagergren-equation and the liquid film diffusion is the predominating step of the sorption process. The adsorption rate equations for CN− and Fe(Ⅲ) are t/Qt=0.057 1 t+2.415 and t/Qt=0.427 9 t+4.572 1, respectively. The adsorption rate constants for CN− and Fe(Ⅲ) are k2=1.35 mL/(g∙min) and k2=39.9 mL/(g∙min). The thermodynamic result indicates =16.78 J/mol and =11.07 J/mol. The sorption process is an endothermic process.
Key words: resin; adsorption; dynamics; thermodynamics
