铝土矿反浮选新型阳离子有机硅类捕收剂QAS222

摘要

The flotation behaviors of diaspore, kaolinite, pyrophyllite illite and their mixture were studied with a novel cationic collector entitled QAS222 and the acting mechnisam of the collector with the minerals was analysed by Zeta potential measuring and FT-IR spectrum analyzing methods. The results indicate that QAS222 is an effective collector in the reverse flotation of bauxite; efficient separations of the mixture at different mass ratios of A12O3 to SiO2 can be achieved in a slurry of pH=ll at a QAS222 concentration of 4X10-4 mol/L. The iso-electric point (IEP) on diaspore surface increases from 6.2 to 10.9 with the addition of QAS222 in the slurry, and these on kaolinite, pyrophyllite and illite are 3.4, 3.0 and 2.5 respectively in the absence of QAS222. Although potentials of the four minerals increase and then decrease at different rates with the increase of slurry pH values, the potential on aluminosilicate minerals are positive in slurry range of pH=2-12, which confirms the flotation results of the minerals. Except for electrostatic adsorptions, formation of hydrogen bond and ammonium absorptions, chemical adsorptions occur between the QAS222 and the kaolinite, pyrophyllite and illite surfaces, which allows for the QAS222 to be strongly absorbed on the mineral surfaces, resulting in their enhanced floatability. However, these actions between the QAS222 and the diaspore surfaces in a slurry of pH=l 1 is weaker than those between the QAS222 and the kaolinite, pyrophyllite and illite surfaces, and wherein subsequently surface adsorptions cannot be formed, resulting in its bad floatability.%考察新型阳离子捕收剂有机硅季铵盐QAS222对一水硬铝石、高岭石、叶蜡石、伊利石4种单矿物及其混合物的浮选行为,并对其机理进行分析.研究结果表明,在碱性条件下,QAS222是铝土矿反浮选脱硅的有效捕收剂;在矿浆pH=ll和QAS222浓度为4×10-4 mol/L条件下,可实现不同铝硅比人工混合矿反浮选脱硅.高岭石、伊利石和叶蜡石零电点分别为3.4,3 0和2 5,一水硬铝石与QAS222作用后零电点由6.2提高至10.9;当QAS222浓度为4×10-4 mol/L时,4种矿物表面动电位随矿浆pH增加不同程度地先增加后减少,但在pH=2～12范围内,3种铝硅酸盐矿物动电位大于0V,证实了单矿物浮选实验结果；QAS222在高岭石、叶腊石和伊利石表面除发生静电吸附作用、氢键作用和铵吸附外,还发生化学吸附,使其牢固地吸附在矿物表面,并在广泛pH范围内保持较好可浮性;而当矿浆pH=ll时,QAS222与一水硬铝石作用较弱,很难形成表面吸附,导致其可浮性较差.