用循环伏安法研究脆硫锑铅矿与捕收剂的作用机理

Interaction mechanism of jamesonite with flotation collectors by cyclic voltammetry

采用循环伏安法研究了脆硫锑铅矿和乙硫氮、乙黄药相互作用的电化学性能,当电极电位φh小于矿物的腐蚀电位φcorr时,捕收剂在矿物表面产生化学吸附,形成吸附膜,起缓蚀作用;在腐蚀电位附近,吸附能力达到最大,并产生钝化作用。当φh≥φcorr时,矿物表面主要表现为捕收剂 金属离子沉积盐,并随电位的升高而氧化分解。化学吸附是乙硫氮与脆硫锑铅矿相互作用的主要特征。乙黄药在脆硫锑铅矿表面产生化学吸附,又形成双黄药。同乙黄药相比,乙硫氮是脆硫锑铅矿更好的捕收剂;当φh<φcorr时,电化学吸附受pH值的影响较小;当φh≥φcorr时,随着pH值升高,电流密度增大,电极过程主要受自身的腐蚀反应所控制,黄药对此起催化作用。

Electrochemistry property of the interaction of jamesonite with diethyl dithiocarbamate and diethyl xanthate by cyclic voltammetry was investigated. The collectors adsorbed chemically and selectively on the unsaturated bonds of metal ions on jamesonite surface in the form of adsorption film to act as an inhibitor when the electrode potential was lower than the corrosive potential. Around the corrosive potential, adsorption action was so strong that the passivation occurred on the electrode surface. The precipitation of collector-metal ions, which would be oxidized and decomposed with the enhancement of the potential, appeared on the mineral surface when the potential was over the corrosive potential. The chemisorption was the important characteristic of the interaction of jamesonite with diethyl dithiocarbamate. Diethyl xanthate not only adsorbed chemically but also became dixanthogen on jamesonite surface. Diethyl dithiocarbamate was a better collector for jamesonite than diethyl xanthate. Electrochemical adsorption was less affected by pH value under the corrosive potential. When the electrode potential was over corrosive potential, the current density increased with the rising of pH value and electrode process was mainly controlled by itself corrosive reactions, which were catalysed by diethyl xanthate.