(1. 中南大學(xué) 化學(xué)化工學(xué)院, 長沙 410083;
2. 中南大學(xué) 地學(xué)與環(huán)境工程學(xué)院, 長沙 410083)
摘 要: 丁黃藥、 Z-200和乙氧羰基硫代氨基甲酸酯（ECTC）浮選永平銅礦小型實(shí)驗(yàn)和工業(yè)實(shí)驗(yàn)結(jié)果表明, 為有效實(shí)現(xiàn)銅硫浮選分離, 丁黃藥要求礦漿pH值不低于12.5, Z-200要求礦漿pH值不低于10.5, 而ECTC只要求礦漿pH值為8.5。采用普遍化微擾理論和密度泛函B3PW91/6-31G(D)計(jì)算從捕收劑結(jié)構(gòu)與性能的關(guān)系對上述實(shí)驗(yàn)結(jié)果進(jìn)行了分析。 ECTC最高占據(jù)分子軌道（HOMO）主要由硫代羰基中硫原子的px和py軌道組成, 其能量為-0.217 29(a.u.), 給電子能力較弱； 最低未占據(jù)分子軌道（LUMO）由官能團(tuán)—O—C(==O)—N—C(==S)—O—中各原子的pz軌道組成, 為共軛π鍵, 接受電子的能力強(qiáng)。 ECTC易與表面電子組態(tài)為(t2g)6(eg)3Cu(Ⅱ)或t6e4 Cu(Ⅰ)的硫化銅礦物形成正配鍵和反饋鍵, 而難與表面電子組態(tài)為(ta2g)3(eag)2Fe(Ⅲ)或(t2g)6Fe(Ⅱ)（堿性條件或弱堿性條件下以Fe(Ⅲ)為主要成分）的硫化鐵礦物作用, 能在pH 8.5的弱堿性介質(zhì)中實(shí)現(xiàn)優(yōu)先選銅。 UV和FTIR光譜結(jié)果進(jìn)一步證實(shí)ECTC捕收劑對銅礦物具有優(yōu)異的捕收能力, 對硫礦物具有好的選擇性。
關(guān)鍵字: 乙氧羰基硫代氨基甲酸酯; 硫化銅礦; 弱堿性; 密度泛函; 選擇性; 浮選
slightly alkaline conditions using ethoxylcarbonyl thionocarbamate as collector
（1. School of Chemistry and Chemical Engineering,
Central South University, Changsha 410083, China;
2. School of Geoscience and Environmental Engineering,
Central South University, Changsha 410083, China）
Abstract: The bench-scale and industrial flotation test results of Jiangxi Copper Corporation Yongping Copper Mine show that the flotation separation of chalcopyrite from pyrite is only achieved above pH 12.5 for butyl xanthate, above pH 10.5 for Z-200 and around pH 8.5 for ethoxylcarbonyl thionocarbamate (ECTC) respectively. The flotation results were analyzed from the structureactivity relationship of collectors by generalized perturbation theory and density functional calculation at B3PW91/6-31G(D) level. ECTC's highest occupied molecular orbit (HOMO) is composed of px and py orbits of thiocarbonyl sulfur atom and its orbital eigenvalue is -0.217 29 a.u.. ECT can slightly donate its HOMO electrons. And the lowest unoccupied molecular orbit (LUMO) of ECTC, which is constituted by pz orbits of every atoms in the conjugate —O—C(==O)—N—C(==S)—O— group, can easily accept electrons. ECTC collector can be strongly bonded with (t2g)6(eg)3Cu(Ⅱ) or t6e4 Cu(Ⅰ) on the surface of chalcopyrite through normal covalent bond and back donation covalent bond, but the interaction between ECTC and (t2g)6Fe(Ⅱ) or (ta2g)3(eag)2 Fe(Ⅲ) which is the predominant composition at alkaline conditions in the surface of pyrite is very weak. In the presence of ECTC, the selective flotation of copper sulfide minerals from iron sulfide minerals in Yongping Copper Mine was carried out at slightly alkaline conditions. ECTC is a powerful collector for chalcopyrite and very selective against pyrite, which is further confirmed by the results of UV and FTIR spectra.
Key words: ethoxylcarbonyl thionocarbamate; copper sulfide minerals; slightly alkaline values; density functional theory; selectivity; flotation
