阴阳离子组合捕收剂在低品位锂云母矿浮选回收中的应用及选择性吸附机理研究

Study on Application and Selective Adsorption Mechanism of Combined Anionic/Cationic Collector in the Flotation Recovery of Low-Grade Lepidolite Ore

针对强酸性矿浆体系(pH=2~3)胺类捕收剂浮选锂云母矿时,存在硫酸耗量高、设备腐蚀严重、浮选泡沫黏度大、废水处理困难等问题,以湖南某含钨锡锂铷多金属矿的钨锡选别尾矿(锂云母浮选给矿,Li_(2)O品位0.44%)为研究对象,在中性矿浆环境和不脱泥条件下,采用阴离子捕收剂WJ和阳离子捕收剂DDA(十二胺)组合对该低品位锂云母矿进行浮选回收,并通过原子力显微镜和芘荧光光谱从微观层面探究了阴阳离子组合捕收剂的协同效应与吸附机理。结果表明:相比单一DDA,采用WJ+DDA组合(质量比3.5∶1),捕收剂用量降低130 g/t,获得的锂云母精矿中Li_(2)O品位提高0.35%,Li_(2)O回收率提高1.41%,且浮选泡沫清爽,脉石夹带少。WJ+DDA组合捕收剂分子更密集地吸附在锂云母表面,而在石英/长石表面基本不发生吸附。相比单一WJ或DDA,WJ+DDA组合捕收剂具有更大的非极性和更强的疏水性,因而具有更高的表面活性。

In the flotation of lepidolite ore in strongly acidic pulp system(pH=2~3) using amine collectors,different issues occur,including high consumption of H_(2)SO_4,serious corrosion of equipment,large viscosity of flotation foam,and difficult wastewater treatment.Using the tungsten-tin separation tailings(lepidolite flotation feed and Li_(2O) grade of 0.44%) from a polymetallic ore containing tungsten,tin,rubi-dium,and lithium in Hunan Province as the study object,a combined anionic(WJ)/cationic(dodecylamine,DDA) collector was used to conduct flotation recovery of the low-grade lepidolite ore under neutral pulp pH and non-desliming conditions,and the synergistic effects and adsorption mechanism of the combined collector were investigated by atomic force microscope(AFM) and pyrene fluorescence spectrum at microscopic level.The results show that compared with using DDA alone,when the combined WJ+DDA with a mass ratio of 3.5∶1 is used,the collector dosage decreases by 130 g/t,the Li_(2O) grade increases by 0.35% and the Li_(2O) recovery rate also increases by 1.41% in the obtained concentrate.Meanwhile,the flotation foam is fresh with less gangue entrainment.The molecules of the combined WJ+DDA collector are densely adsorbed on the surface of lepidolite and barely absorbed on the surface of quartz/feldspar.And compared with using WJ or DDA alone,the combined WJ+DDA collector exhibits greater non-polarity and stronger hydrophobicity,thus possessing higher surface activity.