Separation of aluminosilicates and diaspore from diasporic-bauxite by selective flocculation

Abstract

The flocculation tests of four pure minerals (diaspore, kaolinite, illite, pyrophyllite) and bauxite ore were investigated by the sedimentation. The dispersion behavior of the four pure minerals shows a very good consistency with the variation of zeta potential. The concentrate with the mass ratio of Al₂O₃ to SiO₂ (m(Al₂O₃)/m(SiO₂)) 8.90 and the recovery of Al₂O₃ 86.98% is obtained from bauxite ore (m(Al₂O₃)/m(SiO₂)=5.68) in pH range of 9.5–10.0 by using sodium carbonate (5 kg/t) and sodium polyacrylate (7 g/t) as dispersant and flocculant respectively. Sodium carbonate acts as both pH modifier and favorable dispersant for aluminosilicates. The high performance of sodium polyacrylate on flocculation for diaspore is contributed to the carboxyl of sodium polyacrylate that interacts with active Al sites on diaspore by chemical absorption, and the hydrogen bond effects between hydroxyl group of macromolecule and surface Al-OH on diaspore to accelerate the sedimentation of diaspore.

Keywords

diasporic-bauxite / sodium carbonate / sodium polyacrylate / ratio of Al₂O₃ to SiO₂ / selective flocculation / flocculant / dispersant

References

[1] WangY.-h., HuY.-h., LiuX.-wen.. Flotation de-silicating from diasporic-bauxite with cetyl trimethylammonium bromide [J]. J Cent South Univ Technol, 2003, 10(4): 324-328

[2] LuY.-p., ZhangG.-f., FengQ.-m., OuL.-ming.. A new collector RL for flotation of bauxite [J]. J Cent South Univ Technol, 2002, 9(1): 21-234

[3] WangY.-h., HuY.-h., HeP.-b., GuG.-hua.. Reverse flotation for removal of silicates from diasporic-bauxite [J]. Minerals Engineering, 2004, 17(1): 63-68

[4] ChenW.-k., PengG.-cai.The digestion technology of diasporic bauxite [M], 1997, Beijing, Metallurgical Industry Press

[5] FAN Xiao-hui, LI Guang-hui, JIANG Tao, QIU Guan-zhou. Sintering properties of high iron gibbsite-type bauxite ores [J]. Metal Mine, 2002(7): 16–18. (in Chinese)

[6] HuY.-h., WangY.-h., WangD.-zuo.Flotation chemistry of aluminum and silicate and desilication of bauxite [M], 2004, Beijing, Science Press

[7] HuY.-h., JiangH., QiuG.-z., WangD.-zuo.. Solution chemistry of flotation separation of disporic bauxite [J]. The Chinese Journal of Nonferrous Metals, 2001, 11(1): 125-130

[8] HUANG Chuan-bing, WANG Yu-hua, CHEN Xing-hua, LAN Ye, HU Ye-min, YU Fu-shun. Review of research on desilication of bauxite ores by reverse flotation [J]. Metal Mine, 2005(6): 21–24. (in Chinese)

[9] HuangC.-b., WangY.-h., LanYe.. Mechanism of selective flocculation separation of diasporic bauxite with organic flocculant HSPA [J]. The Chinese Journal of Nonferrous Metals, 2006, 16(7): 1250-1256

[10] OzkanA., UsluZ., DuzyolS., UcbeyiayH.. Correlation of shear flocculation of some salt-type minerals with their wettability parameter [J]. Chemical Engineering and Processing: Process Intensification, 2007, 46(12): 1341-1348

[11] JonasA. M.. Enhanced flocculation and dewatering of clay mineral dispersions [J]. Powder Technology, 2007, 179(1/2): 73-78

[12] Klein WolterinkJ., KoopalL. K., Cohen StuartM. A., van RiemsdijW. H.. Surface charge regulation upon polyelectrolyte adsorption, hematite, polystyrene sulfonate, surface charge regulation: Theoretical calculations and hematite-poly(styrene sulfonate) system [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2006, 291/300(1/3): 13-23

[13] OzkanA., UcbeyiayH., AydoganS.. Shear flocculation of celestite with anionic surfactants and effects of some inorganic dispersants [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2006, 281/290(1/3): 92-98

[14] SomasundaranP., RunkanaV.. Investigation of the flocculation of colloidal suspensions by controlling adsorbed layer microstructure and population balance modelling [J]. Chemical Engineering Research and Design, 2005, 83(7): 905-914

[15] WANG Yu-hua, HU Yue-hua, HE Ping-bo, GU Guo-hua. Test research on selective desliming of bauxite [J]. Metal Mine, 2004(4): 38–40. (in Chinese)

[16] XiaX.-h., LiG.-x., KuangY.-f., LiuG.-gen.. The ESR investigation on adsorption behaviour of sodium polyacrylate at Al₂O₃/water interface [J]. Ion Exchange and Adsorption, 2003, 19(2): 127-132