XU Long-hua, DONG Fa-qin, WU Hou-qin, LIU Jing, WANG Zhen, WANG Jin-ming

(Key Laboratory of Solid Waste Treatment and Resource Recycle Ministry of Education,
Southwest University of Science and Technology, Mianyang 621010, China)

Abstract: The practice of flotation on bauxite, often use a fatty acid (oleic acid) as an anionic collector for selective separation of diaspore from other aluminum silicate minerals such as kaolinite. Surface crystal chemistry of minerals is found to be the decisive factor for selective flotation separation. In the sodium oleate (NaOL) flotation system, the flotability of diaspore and kaolinite was studied. It was found that results for the flotation of diaspore are significantly better than that of kaolinite. The infrared spectral analysis show that Al sites on the surface of minerals react with carboxyl group of oleic acid by chemisorption. The surface broken bond densities and the interaction energy of planes to reagents were calculated using Materials Studio software. The results found that the sizes of the surface broken bond densities of the mineral crystal planes and interaction energy with oleate ions for diaspore are (100) > (001) > (010), and (010) > (110) > (001) for kaolinite. As well, interaction energies between three planes of diaspore crystal and oleic acid are stronger than those for kaolinite. We conclude that the flotability difference between kaolinite and diaspore can attributed to the different numbers of broken bond Al-O on different mineral crystal planes.

Keywords: diaspore; kaolinite; oleate; surface crystal chemistry; broken bond; flotation

Email: neuxulonghua@163.com

ACTA MINERALOGICA SINICA Vol. 36, No. 2, 2016, Page 265-270