Mechanism of phthalic acid collector in flotation separation of fluorite and rare earth  

作　　者：Sheng Chang Mei Li Kai Gao Dongliang Zhang Haijun Duan Linlin Ma Zheng Ruan 

机构地区：[1]College of Mining,Inner Mongolia University of Science&Technology,Baotou 014010,China [2]Key Laboratory of Green Extraction&Efficient Utilization of Light Rare-Earth Resources Ministry of Education,Baotou 014010,China [3]Inner Mongolia Key Laboratory of Rare Earth Hydrometallurgy and Light Rare Earth Application,Baotou 014010,China [4]Inner Mongolia Mining Exploitation Co.,Ltd.,Hohhot 010020,China

出　　处：《Journal of Rare Earths》2022年第1期118-126,共9页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(51634005,51564042);Inner Mongolia Autonomous Region Natural Science Foundation(2014ZD04.2016ZD05)。

摘　　要：The mechanism of phthalic acid,a dicarboxylic acid collector,in flotation separation of fluorite and rare earth(RE)was studied in this paper.The experimental data of flotation show that phthalic acid,as the collector,can realize highly efficient separation of fluorite and rare earth under weakly acidic conditions.The adsorption mechanism of phthalic acid on the surface of fluorite and bastnaesite was analyzed in this paper by means of the zeta potential measurement,the Fourier transform infrared(FT-IR),the X-ray photoelectron spectroscopy(XPS)and the stability constant measurement of active metal ion and phthalic acid coo rdination complex.According to the zeta potential testing results,the surfaces of fluorite adsorb the collector phthalate ion with negative charge under weakly acidic conditions which,in turn,increases its electronegativity and results in the motion of its potential.After the reaction between phthalic acid and fluorite ores under weakly acidic conditions,the peak of the fluorite ores is found to have significant changes in the FT-IR results,indicating strong chemical adsorption on the surfaces of phthalic acid and fluorite ores.According to the XPS analysis,the peak of benzene ring of phthalic acid is as high as 2%on the surface of fluorite,while no obvious characteristic peak of benzene ring is found on the surface of bastnaesite.According to the pH potentiometric titration results,the stability constant Ktotal of calcium phthalate complex within the acid range is higher than the stability constant K’total of cerium phthalate complex,indicating that the complex generated between phthalic acid and Ca^(2+)is more stable than the complex generated between phthalic acid and Ce^(3+).The possible reason is that Ca^(2+),with the highest reticular density,plays a prevailing role in the octahedron structure of fluorite amidst the acidic media.As the active point of flotation,Ca^(2+)works with the carboxyl groups of the collector phthalic acid(-C=O-)to form polycyclic calcium phthalate complex.

关 键 词：FLUORITE BASTNAESITE Carboxylic acid collector FLOTATION Equilibrium constants of complexes Rare earths 

分 类 号：TD923[矿业工程—选矿] TD97TD955