( 1. 衡陽師范學院 化學與材料科學系， 衡陽 421008;
2. 中南大學 資源加工與生物工程學院， 長沙 410083)
摘 要: 采用光譜分析、 循環(huán)伏安及恒電位階躍法， 研究了乙硫氮(NaD)在鐵閃鋅礦表面吸附的電化學行為及機理， 該機理與浮選電化學的混合電位模型并不一致。 在酸性條件下， 當電位為0~200 mV時， 乙硫氮在鐵閃鋅礦表面電化學吸附形成雙乙硫氮(D2)； 當電位為410mV時, 乙硫氮與礦物發(fā)生電化學反應(yīng)形成ZnD2和S0, 并產(chǎn)生鈍化， 且表面疏水性強； 當電位大于600 mV, 電極過程由自腐蝕反應(yīng)控制。 在中性和堿性條件下， 鐵閃鋅礦表面的電極過程主要由自腐蝕陽極溶解控制。 隨著pH值的增大, 表面中間態(tài)分別為Fe(OH)D2、 Fe(OH)2D和Zn(OH)D， 并隨電位增大進一步氧化成Zn(OH)2、 Fe(OH)3和D2， 且礦物表面親水性強。 在開路電位條件下， 鐵閃鋅礦表面存在雙乙硫氮和乙硫氮金屬鹽， 但不能有效地附著在電極表面。
關(guān)鍵字: 鐵閃鋅礦； 乙硫氮； 吸附； 浮選電化學
（ 1. Department of Chemistry and Material Science, Hengyang Normal University, Hengyang 421008, China;
2. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract: The electrochemical adsorption behavior and mechanism of diethyl dithiocarbamate (NaD) on the surface of marmatite, which are different from the mixed potential model of flotation electrochemistry, were studied by spectrum analysis, CA voltammetry and constant potential step. Under acidic condition, the dimer diethyldithiocarbamate (D2) is formed on marmatite through the electrochemical adsorption of diethyl dithiocarbamate at 0-200mV. ZnD2 and S0 are formed by electrochemical reaction and result in the passivation at 410mV, and the surface of marmatite has strong hydrophobicity. The electrode process is controlled by self-corrosive reaction at over 600mV. Under the condition of the neutral and base, the electrode process of marmatite is basically controlled by the anodic self-corrosion. With the increasing pH, the intermediates on the surface of marmatite are Fe(OH)D2, Fe(OH)2D, Zn(OH)D, respectively, which will be further oxidized into Zn(OH)2, Fe(OH)3 and D2 with the increase of the potential, and the surface of marmatite has strong hydrophilicity. There exist both dimer D2 and diethyl dithiocarbamate salts on the surface of marmatite at open-circuit potential, which can not effectively adhere on the surface of marmatite.
Key words: marmatite; diethyl dithiocarbamate; adsorption; flotation electrochemistry
