(1. 北京礦冶研究總院，北京 100160；
2. 東北大學(xué) 冶金學(xué)院，沈陽 110006；
3. 中國科學(xué)院 過程工程研究所 濕法冶金清潔生產(chǎn)技術(shù)國家工程實驗室，北京 100190；
4. 北京科技大學(xué) 冶金與生態(tài)制造工程學(xué)院，北京 100083)
摘 要: 本文以成型殼聚糖為吸附劑進行溶液中Ni-Co的分離，通過Ni2+和Co2+與殼聚糖上氨基的絡(luò)合能力差異達到Ni2+、Co2+分離的目的。結(jié)果表明：利用NaOH與殼聚糖醋酸溶液可制備出粒度約為60 μm的層狀成型殼聚糖；成型殼聚糖對Ni2+、Co2+的吸附符合擬二級動力學(xué)方程和Freundlich方程；經(jīng)吸附焓變計算發(fā)現(xiàn)成型殼聚糖對Ni2+的吸附為吸熱反應(yīng)，而對Co2+的吸附為放熱反應(yīng)；吸附機理表明，殼聚糖上的氨基和羥基與Ni2+、Co2+發(fā)生結(jié)合反應(yīng)。以萃取分離后得到的高Co2+低Ni2+溶液為原料，成型殼聚糖吸附后溶液中Ni2+含量由73×10-6降低至30×10-6，實現(xiàn)雜質(zhì)的深度脫除。
關(guān)鍵字: 鎳；鈷；吸附；選擇性分離；殼聚糖；改性
（1. Beijing General Research Institute of Mining & Metallurgy, Beijing 100160, China;
2. School of Metallurgy, Northeastern University, Shenyang 110006, China;
3. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
4. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Ni and Co are difficult from separation due to their similar physicochemical properties. Based on the difference in complexation ability between ammonia and Ni/Co, selective separation of Ni2+ and Co2+ was conducted by using modified chitosan as adsorbent with amino group. The results show that the modified chitosan with the size of 60 μm can be prepared by mixing chitosan-acetic acid solution with NaOH. The adsorption behavior of Ni2+ and Co2+ onto modified chitosan, including adsorption isotherm and kinetics, is fitted well by Freundlich model and pseudo-second- order model, respectively. Adsorption enthalpy results indicate that the Ni2+ uptake onto modified chitosan is endothermic while the Co2+ uptake is exothermic. The adsorption mechanism shows that the Ni2+ and Co2+ are chelated with amino and hydroxyl groups of modified chitosan. In the specific application, Ni2+ content of high concentrated Co2+ solutions decreases from 73×10-6 to 30×10-6, realizing the selective separation of Ni.
Key words: nickel and cobalt; adsorption; selective separation; chitosan; modification
