(1. 江西理工大學(xué) 資源與環(huán)境工程學(xué)院，贛州 341000；
2. 中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410000)
摘 要: 采用量子化學(xué)計算、紅外光譜分析研究了環(huán)烷酸在鋰輝石表面的吸附行為。通過計算表面能選取鋰輝石(110)面為最佳解理面，并構(gòu)建了無虛頻的穩(wěn)定環(huán)烷酸分子模型，運用分子動力學(xué)模擬得到環(huán)烷酸與鋰輝石(110)面的最佳吸附構(gòu)型。對最優(yōu)吸附構(gòu)型進(jìn)行了量子化學(xué)計算，研究了其結(jié)構(gòu)、電荷分布、差分電荷密度以及態(tài)密度等。結(jié)果表明：鋰輝石(110)面吸附環(huán)烷酸分子后表面原子都向鋰輝石內(nèi)部弛豫，環(huán)烷酸吸附后的構(gòu)型發(fā)生明顯的變化，其羰基氧原子負(fù)電性得到增強，非羰基原子的負(fù)電性得到削弱，環(huán)烷酸與鋰輝石的作用是通過羰基氧原子實現(xiàn)的。環(huán)烷酸與鋰輝石吸附后，鋰輝石(110)面的電子云重新分配，氧原子的電荷云密度增強并向周圍區(qū)域發(fā)散開來，環(huán)烷酸整體態(tài)密度峰左移且費米能級附近的態(tài)密度峰由價帶變?yōu)閷?dǎo)帶，體系趨向于穩(wěn)定存在。紅外光譜分析進(jìn)一步表明：環(huán)烷酸在鋰輝石表面吸附是物理吸附作用。
關(guān)鍵字: 量子化學(xué)計算；鋰輝石(110)面；環(huán)烷酸；吸附構(gòu)型
（1. Faculty of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;
2. School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The mechanism of flotation of naphthenic acid on spodumene was studied by using the method of quantum chemistry calculation and infrared spectrum analysis. The paper has selected the (110) surface as the best cleavage plane by calculating different surfaces’ energy and has built stability naphthenic acid model with no imaginary frequency, then has got the best configuration for adsorption of naphthenic acid on spodumene (110) surface by using the method of molecular dynamics simulation. The structure, charge distribution, differential charge density and state density to the best adsorption configuration were studied. The results show that the atoms on the (110) surface relaxes to the spodumene inside when the naphthenic acid molecule is adsorbed on the (110) surface. At the same time, the configuration of the naphthenic acid changes obviously. The electronegative of the carbonyl oxygen atoms is stronger and those of the other oxygen atoms are weakened to the adsorbed naphthenic acid molecule. The interaction between naphthenic acid and spodumene is achieved by carbonyl atoms. After adsorption, the electron cloud is redistributed and the charge cloud density of the oxygen atoms increase and spread to the surrounding area on the spodumene (110) surface. The state density peak of the naphthenic acid molecule shifts to the left but the peak near the Fermi lever has changed from valence band to the conduction band. The adsorption structure tends to be stable. The infrared spectral analysis further shows that the naphthenic acid is physical adsorption on the spodumene surface.
Key words: quantum chemical calculation; spodumene (110) surface; naphthenic acid; adsorption configuration
