(中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083)
摘 要: 合成一種新型的表面活性劑——N-異丁氧羰基硫脲(iBCTU)，對(duì)其結(jié)構(gòu)進(jìn)行紅外和核磁共振表征，并考察其對(duì)黃銅礦的浮選性能以及在黃銅礦表面的吸附熱力學(xué)和機(jī)理。浮選和吸附結(jié)果表明：在pH 3~11的范圍內(nèi)，iBCTU對(duì)黃銅礦具有良好捕收能力，且黃銅礦對(duì)iBCTU的吸附量隨著溫度的升高而增大。熱力學(xué)分析表明：iBCTU在黃銅礦表面的吸附等溫線符合Langmuir模型，吸附焓變?chǔ)為56.42 kJ/mol，熵變?chǔ)為284.76 J/(mol·K)，吸附自由能變?chǔ)為-29.12 kJ/mol(298K)，iBCTU在黃銅礦表面的吸附為自發(fā)、吸熱化學(xué)吸附過程。XPS分析進(jìn)一步說明iBCTU可能通過其硫代羰基的硫原子和—NH2基氮原子與黃銅礦表面的銅原子結(jié)合生成iBCTU-Cu(Ⅰ)表面絡(luò)合物吸附在黃銅礦表面。
關(guān)鍵字: N-異丁氧羰基硫脲；黃銅礦；吸附熱力學(xué)；浮選；XPS
（School of Chemistry and Chemical Engineering, Central South Univeristy, Changsha 410083, China）
Abstract:A novel surfactant, N-isobutoxycarbonyl thiourea (iBCTU) was synthesized and characterized by infrared spectroscopy, H nuclear magnetic resonance (HNMR) and C nuclear magnetic resonance (CNMR). Its flotation performance, adsorption thermodynamics and mechanism for the chalcopyrite were evaluated. The results of micro-flotation and adsorption tests show that iBCTU exhibits excellent hydrometallurgical performance for chalcopyrite under pH 3-11, and the adsorption capacity increases with increasing temperature. The adsorption isotherm agrees well with Langmuir model and the thermodynamics parameters ΔH (enthalpy change), ΔS (entropy change) and ΔG (free energy change) are 56.42 kJ/mol, 284.76 J/(mol·K) and -29.12 kJ/mol (298K), respectively, which infers that the adsorption of iBCTU on the chalcopyrite surface is a spontaneous and endothermic chemisorption. The XPS results further demonstrate that iBCTU might bond with the copper atoms on the chalcopyrite surface through its sulfur (—C=S) and nitrogen (—NH2) atoms to form iBCTU-Cu(Ⅰ) surface complexes.
Key words: N-isobutoxycarbonyl thiourea; chalcopyrite; adsorption thermodynamics; flotation; XPS
