(1. 長沙礦冶研究院有限責任公司，長沙 410012； 2. 中南大學 化學化工學院，長沙 410083； 3. 南開大學 化學學院，天津 300071)
摘 要: 通過純孔雀石、硫化-氧化混合銅礦浮選試驗、FT-IR光譜分析、Zeta電位測試、捕收劑及礦物溶液化學分析和DFT計算研究2-乙基-2-烯己基羥肟酸(EHHA)對孔雀石礦物的直接浮選性能及吸附機理。純礦物浮選試驗結(jié)果表明：EHHA是一種直接浮選孔雀石礦物的優(yōu)良捕收劑，在礦漿pH值 6、用量200 mg/L的浮選條件下，EHHA能直接浮選出95.33%的孔雀石。實際礦石浮選試驗結(jié)果表明：EHHA在弱酸性條件下直接浮選硫化-氧化銅礦與使用異丁基黃藥(IBX)捕收劑硫化浮選相比較，EHHA所取得的粗精礦中Cu回收率高了1.87%。FT-IR光譜和Zeta電位測試結(jié)果表明：EHHA通過形成五元螯合環(huán)吸附于孔雀石礦物表面。孔雀石和捕收劑的溶液化學分析表明：EHHA通過與礦物表面的Cu2+螯合成沉淀而發(fā)生吸附，OHA通過與孔雀石礦物表面的水合銅離子發(fā)生表面化學反應(yīng)而吸附于礦物表面，相關(guān)的FT-IR分析結(jié)果進一步證實這一結(jié)論。DFT計算結(jié)果表明：EHHA比IBX擁有更大的偶極矩，更高的Mulliken電荷，對孔雀石礦物的捕收能力更強。
關(guān)鍵字: 2-乙基-2-烯己基羥肟酸；孔雀石；浮選；吸附
（1. Changsha Research Institute of Ming and Metallurgy Co., Ltd., Changsha 410012, China; 2. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China; 3. School of Chemistry, Nankai University, Tianjin 300071, China）
Abstract:The direct flotation behavior and adsorption mechanism of 2-ethyl-2-hexenoic hydroxamic acid (EHHA) to malachite were investigated by micro-flotation tests of pure minerals, bench scale flotation tests of sulfide-oxide mixed actual copper ore, FT-IR spectra, Zeta potential measurements, solution chemistry analyses of collectors and minerals, and density functional theory (DFT) calculations. The direct micro-flotation results of pure minerals indicate that EHHA exhibits superior flotation performance to malachite, and floates out 95.33% malachite at pH=6 with dosage of 200 mg/L. The results of flotation tests of sulfide-oxide actual copper ore show that, the Cu recovery rate obtained by EHHA’s direct flotation under the condition of weak acid pulp is 1.87% higher than that obtained by isobutyl xanthate’s (IBX) sulfide flotation. The analyses of FT-IR spectra and Zeta potential demonstrate that EHHA might chemisorb onto malachite surfaces by form of five-membered chelates. The solution chemistry analyses of collectors and minerals indicate that EHHA and OHA might be adsorbed onto malachite surfaces by form of chelates with Cu2+ and Cu2+ hydroxyl complex compounds, respectively, and the related FT-IR analysis results further confirm this conclusion. DFT calculation results imply EHHA owns stronger affinity to malachite due to owning a larger dipole moment and higher Mulliken charge comparing to IBX.
Key words: 2-ethyl-2-hexenoic hydroxamic acid; malachite; flotation; adsorption
