(中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 在MnSO4-(NH4)2SO4溶液中，以鋁板為陰極電沉積金屬錳，分別研究電流密度、電解液成分、溫度等因素對(duì)陰極電流效率、能耗和陰極產(chǎn)物的影響。結(jié)果表明：在含Mn2+溶液濃度為30 g/L、(NH4)2SO4濃度為130 g/L、SeO2濃度為0.04g /L、初始pH值為7.0、電流密度為400 A/m2、電解溫度為35 ℃時(shí)，鋁陰極的陰極電流效率為85.8%，能耗為4870.9 kW？h/t，得到的金屬錳純度高于99.5%，晶型為α-Mn。與傳統(tǒng)不銹鋼陰極(0Cr19Ni9)對(duì)比，Mn2+在鋁陰極表面的起始沉積電位與在不銹鋼陰極表面的相同，但在電沉積初期可以抑制H2的析出；鋁陰極可加速M(fèi)n2+的電沉積，增加陰極電流效率，降低直流電耗；同時(shí)，鋁陰極可以抑制SeO32-的還原，減小添加劑SeO2的消耗量，提高陰極錳的純度。因此，金屬鋁具備替代不銹鋼作為電沉積金屬錳的潛力。
關(guān)鍵字: 錳電解；鋁陰極；電流效率；能耗；SeO2
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:Aluminum was adopted as cathodic material for manganese electrodeposition from the MnSO4-(NH4)2SO4 solution. The influences of the current density, electrolyte composition and temperature were studied on the cathodic current efficiency, energy consumption and cathodic products. The results show that, the cathodic current efficiency and the energy consumption can reach to 85.8% and 4870.9 kW？h/t, under the following conditions: Mn2+ concentration of 30 g/L, (NH4)2SO4 concentration of 130 g/L, SeO2 concentration of 0.04 g/L, temperature of 35 ℃, pH of 7.0 and cathode current density of 400 A/m2. The purity of product can achieve more than 99.5% and the crystal form is α-Mn. Compared with traditional stainless steel (0Cr19Ni9), the onset potential of manganese electrodeposition on aluminum cathode is not changed, while the hydrogen evolution is suppressed at initial period of electrodeposition. Aluminum cathode can accelerate the discharge rate of Mn2+ and improve the cathodic current efficiency, and then decrease the energy consumption. The reduction of SeO32- on aluminum cathode is weakened, which can reduce the consumption of SeO2 and improve the purity of product. This study indicates that aluminum has the potential to be candidate of stainless steel for manganese electrodeposition.
Key words: manganese electrodeposition; aluminum cathode; current efficiency; energy consumption; SeO2
