疏水强化浮选:双亲矿基捕收剂与常规捕收剂的对比

Hydrophobic intensification flotation:Comparison of collector containing two minerophilic groups with conventional collectors

通过接触角和单矿物浮选试验,对比研究黄原酸酯−羟肟酸双配体捕收剂与黄原酸酯+羟肟酸组合捕收剂对氧化铜矿物浮选和疏水性能。结果表明,S−[(2−羟胺基)−2−乙酰基]−O−辛基−二硫代碳酸酯(HAOODE)对孔雀石的疏水化能力和浮选性能优于辛基羟肟酸(OHA)及其与S−烯丙基−O−乙基黄原酸酯(AEXE)的组合。通过动电位测试、原子力显微镜扫描和XPS分析,考察HAOODE对孔雀石的疏水强化机理。结果显示,HAOODE化学吸附在孔雀石表面,形成含羟肟酸—(O,O)—Cu和—O—C(—S—Cu)—S—构型的表面Cu—HAOODE络合物。HAOODE的双官能团共吸附产生了“环”形结构,比OHA和AEXE的单官能团吸附更稳定,强化其在孔雀石表面的吸附。此外,与OHA的“线”形和AEXE的“V”形疏水碳链相比,HAOODE的“h”形双疏水基强化了孔雀石表面疏水。因此,与OHA和AEXE相比,HAOODE对孔雀石颗粒浮选回收率更高。

The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and micro-flotation experiments.The results showed that S-[(2-hydroxyamino)-2-oxoethyl]-O-octyl-dithiocarbonate ester(HAOODE)exhibited stronger hydrophobization and better flotation performance to malachite(Cu2(OH)2CO3)than octyl-hydroxamic acid(OHA)and its combination with S-allyl-O-ethyl xanthate ester(AEXE).To understand the hydrophobic intensification mechanism of HAOODE to malachite,zeta potential,atomic force microscopy(AFM)and XPS measurements were carried out.The results recommended that malachite chemisorbed HAOODE to form Cu—HAOODE complexes in which the hydroxamate—(O,O)—Cu and—O—C(—S—Cu)—S—configurations co-existed.The co-adsorption of HAOODE’s hetero-difunctional groups was more stable than the single-functionalgroup adsorption of OHA and AEXE,which produced the“loop”structure and intensified the self-assembly alignment of HAOODE on malachite surfaces.In addition,the“h”shape steric orientation of the double hydrophobic groups in HAOODE facilitated stronger hydrophobization toward malachite than the“line”or“V”hydrophobic carbon chains of OHA or AEXE.Thus,HAOODE achieved the preferable flotation recovery of malachite particles in comparison with OHA and AEXE.