(1. 中南大學 化學化工學院，長沙 410083；
2. 中南大學 地學與環(huán)境工程學院，長沙 410083)
摘 要: 對乙氧羰基硫脲和丁黃藥組合捕收劑方案浮選德興銅礦進行了小型和工業(yè)試驗研究。結(jié)果表明，與丁黃藥單一捕收劑方案相比，組合捕收劑方案可使石灰用量降低2/3，實現(xiàn)銅鐵混合精礦在pH值為10.5左右的高效浮選分離，顯著提高礦山銅、金和鉬的回收率。采用普遍化微擾理論和密度泛函B3PW91/6-31G(D)計算對上述實驗結(jié)果進行了理論分析。ECTU的反應中心為硫代羰基中的硫原子，ECTU的最高占據(jù)分子軌道與次最高占據(jù)分子軌道的能量接近，主要由硫代羰基中的硫原子組成。ECTU的最低未占據(jù)分子軌道由官能團—O—C(=O)—N—C(=S)—N—中各原子的pz軌道組成，為一大π鍵，具有強烈接受和分散電子對的能力。ECTU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(t2gа)3(egа)2 Fe(Ⅲ)或(t2g)6Fe(Ⅱ)的硫化鐵礦物作用。UV和FTIR光譜結(jié)果進一步證實了ECTU對銅礦物具有優(yōu)異的捕收能力，對硫礦物具有較好的選擇性。
關鍵字: 乙氧羰基硫脲；銅硫；捕收劑；回收率；浮選；分離
（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’s Dexing Copper Mine show that the flotation separation of Cu/Fe sulfide minerals is achieved at pH value about 13 for sodium butyl xanthate (SBX) and pH value around 10.5 for combined collectors ethoxylcarbonyl thiourea (ECTU) and SBX. Compared with the SBX system, the consumption amount of lime decreases 2/3 and the recoveries rates of Cu, Au and Mo in the copper concentrates increase by the combined collectors system. The flotation results were analyzed from the structure-activity of collectors by generalized perturbation theory and density functional calculation at B3PW91/6-31G(D) level. The S atom of C=S group in ECTU molecule is at the reactive centre of ECTU. The highest occupied molecular orbit (HOMO) of ECTU and next higher occupied molecular orbit (NHOMO) are mainly constitued by p-orbit of thiocarbonyl sulfur atom and their orbital eigenvalues have similar values. The lowest unoccupied molecular orbit (LUMO) of ECTU, which is constituted by pz-orbit of every atoms in the conjugate —O—C(=O)—N—C(=S)—N— group and pleased with accepting richly d-orbital electrons (feedback electrons) from the (t2g)6(eg)3Cu(Ⅱ) or t6e4 Cu(Ⅰ) configuration of copper cation on the surfaces of copper sulfide minerals, results in the formation of dative π-bond. The iron atom, which has a (t2g)6(eg)0Fe(Ⅱ) or (t2gа)3(egа)2 Fe(Ⅲ) configuration on the surfaces of iron sulfide minerals, has difficulty in offering its d-orbital electrons (feedback electrons) to LUMO of ECTU. ECTU collectors are powerful for copper sulfide minerals and very selective against iron sulfides, which is further confirmed by UV and FTIR spectra.
Key words: ethoxylcarbonyl thiourea; Cu/Fe sulfide minerals; collector; recovery rate; flotation; separation
