(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 采用單因素試驗法，研究某低品位硫化銅精礦(Cu 7.42%(質(zhì)量分數(shù)))在NH3-NH4Cl-H2O體系中的氧化浸出行為。結(jié)果表明：在液固比 4:1、[NH3·H2O]=1 mol/L、[NH4Cl]=3 mol/L、氧化劑過量系數(shù)1.4、原料粒度94~124 μm、浸出時間2 h、溫度30℃的條件下，該低品位硫化銅礦浸出率98.89%；并在此基礎(chǔ)上開展了從該低品位硫化銅精礦銅氨浸出液中直接脈沖電積銅的工藝優(yōu)化試驗。結(jié)果表明：在[NH4Cl]=3 mol/L、[NH3·H2O]=1.5 mol/L、[Cu2+]=20 g/L、明膠0.06 g/L、硫脲0.05 g/L、脈沖電流密度600 A/m2、占空比90%的條件下，可以獲得平整光滑且有金屬光澤的陰極銅，陰極電流效率87.97%。陰極銅XRD分析結(jié)果表明：氨-氯化銨體系中脈沖電積銅晶體主要沿(220)晶面生長，其余晶面未見明顯反射峰，表現(xiàn)出類單晶結(jié)構(gòu)。SEM分析顯示：該陰極銅表面光滑致密且無瘤狀物產(chǎn)生，銅在陰極表面的生長方式呈與陰極面垂直的一維方向生長。
關(guān)鍵字: 低品位硫化銅精礦；氨性氧化浸出；脈沖電積
（School of Metallurgy and Environmental, Central South University, Changsha 410083, China）
Abstract:The oxidative leaching behaviors of a low grade copper sulfide concentrate in NH3-NH4Cl-H2O were investigated by using single-factor experiment method. The results show that 98.89% copper can be leached under the conditions of liquid-solid ratio 4:1, NH3·H2O concentration 1.0 mol/L, ammonium chloride concentration 3.0 mol/L, 1.4 times stoichiometric oxidant dosage, particle size 94-124 μm, contact time 2 h and temperature 30℃. In addition, the optimization experiments of direct pulse copper electro-deposition from this cuprammonia leach solution were carried out. A flat and metallic luster cathode copper plate with cathode current efficiency 87.97% is obtained under the optimized conditions NH4Cl concentration 3 mol/L, NH3·H2O concentration 1.5 mol/L, Cu2+ concentration 20 g/L, gelatin concentration 0.05 g/L, thiourea concentration 0.06 g/L, pulse current density 600 A/m2 and duty cycle 90%. XRD analysis results of the resultant cathode copper show that the copper crystal in the ammonia system grow mainly along (220) crystal surface, and there is no obvious reflection peak on the other crystal faces, which show that the cathode copper is analogous to single crystal structure. SEM analysis results show that the surface of the cathode copper is smooth, compact and without tumor on the surface. The growth of copper on the cathode surface is in one-dimensional direction perpendicular to the cathode surface.
Key words: low grade copper sulfide concentrate; oxidative ammonia leaching; pulse electrodeposition
