甲基磺酸体系粗铅电解精炼的电沉积行为与概念验证运行（英文）

提出一种替代传统氟硅酸体系的甲基磺酸(MSA)体系,它具有挥发性低、腐蚀性低、热稳定性良好和导电性高的优点,能够实现绿色高效铅电解精炼。探讨基于MSA体系的粗铅电精炼(MPR)电沉积行为,包括其运行机理、反应可逆性、形核和生长模式。基于循环伏安法(CV)和计时电流法(CA),揭示受扩散控制且不可逆的MPR铅沉积过程,建立MPR铅沉积形核和生长的瞬态成核理论模型。MPR小规模验证性运行实现了104.22 kW·h/t Pb的能耗和99.24%的电流效率,相较于H₂SiF₆体系的120 kW·h/tPb能耗与95%电流效率,具有竞争性。MPR小规模运行获得了纯度99.9925%且光滑致密的铅沉积层,满足铅锭纯度99.97%的标准(GB/T 469—2013)。     

Preparation of high-purity tantalum ethoxide by vacuum distillation

Effects of reflux ratio, water addition and content of water in ethanol on the purity and yield of tantalum ethoxide during vacuum distillation were investigated under the operational conditions of pressure of 1kPa, oil bath temperature of 210-230 ℃, and outlet temperature of 190℃. The condensate sample was characterized by FTIR, 1↑H-NMR spectroscopy and Raman spectra, respectively. The contents of tantalum, carbon and hydrogen in the sample were also determined with elemental analysis instrument. The obtained results consistently demonstrate that the condensate is tantalum ethoxide. The content of impurity, such as Al, As, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Sn, Ti, V and Zn, in tantalum ethoxide is less than 0.000 05%, while Nb content is less than 0.000 5%. The content of impurities in tantalum ethoxide sample excels that of Epichem Group＇s requirement for Ta（OC2H5）5 of 99.999%.     

乙二醇还原生产硬质合金用钴粉

以自制Co(OH)₂ 为原料, 乙二醇为溶剂和还原剂, 制得了分散性很好的球形超细钴粉。研究了单位体积乙二醇中Co(OH)₂加入量对钴粉的粒径和形貌的影响。用SEM 、XRD、BET 和激光粒度分析仪测试粉体的粒子形貌、晶体结构、比表面积和粒度分布。测试结果表明多元醇还原的钴粉为球形, 晶体结构以面心立方为主, 还有微量的简单六方;当Co(OH)₂ 加入量为60 g/ L 时制得的钴粉粒度分布较窄, 平均粒径为0.88 μm, 比表面积为3.46 m²/ g, 钴含量>99.5%。     

Thermodynamics of Zn(Ⅱ)-NH_3-NH_4Cl-H_2O system

1　ＩＮＴＲＯＤＵＣＴＩＯＮＡｍｍｏｎｉａｚｉｎｃｍｅｔａｌｌｕｒｇｙｈａｓｔｈｅｍｅｒｉｔｓｏｆｅａｓｙｐｕｒｉｆｉｃａｔｉｏｎａｎｄｓｉｍｐｌｉｆｉｅｄｐｒｏｃｅｓｓ ,ｓｏｉｔｈａｓｂｅｅｎｒｅ ｓｅａｒｃｈｅｄｅｘｔｅｎｓｉｖｅｌｙ .Ｗｅｈａｖｅｓｔｕｄｉｅｄｕｐｔｈｅｔｈｅｒｍｏ ｄｙｎａｍｉｃｓｉｎｔｈｅｓｙｓｔｅｍｓｏｆＺｎ(Ⅱ ) ＮＨ3 (ＮＨ ) 2 ＳＯ4 Ｈ2 Ｏ[1] ａｎｄＺｎ(Ⅱ ) ＮＨ3 (ＮＨ) 2 ＣＯ3 Ｈ2 Ｏ[2 ] ａｎｄｄｉｓ ｃｏｖｅｒｅｄｔｈｅｒｕｌｅｓｏｆｚｉｎｃｓｏｌｕｂｉｌｉｔｙ …     

Electrochemical synthesis, characterization and thermal properties of niobium ethoxide

Niobium(V) ethoxide (Nb(OEt)₅) was synthesized by electrochemical reaction of ethanol with niobium plate as the sacrificial anode, stainless steel as the cathode and tetraethylammonium chloride (TEAC) as the conductive additive. The condensates were isolated by vacuum distillation under 5 kPa. The product was characterized by Fourier transform infrared (FT-IR) spectra, Raman spectra and nuclear magnetic resonance (NMR) spectra. The results indicate that the product is niobium ethoxide. Thermal properties of niobium ethoxide were analysed by TG/DTG. Vapour pressure was calculated from the Langmuir equation and the enthalpy of vaporization was calculated from the vapour pressure-temperature data using the Clausius-Clapeyron equation. The concentrations of impurity metallic elements in the sample were detected by ICP-MS. It is shown that the purity can reach 99.997%. The volatility and purity of the niobium ethoxide ensure that it could be a good precursor for chemical vapor deposition and atomic layer deposition of niobium oxide layers.     

碳化法制备碱式碳酸锌过程的热力学分析及其产物表征

分析了碳化法制备碱式碳酸锌过程的热力学,并对产物进行了表征。结果表明,锌以ZnCO3.2Zn(OH)2.H2O形式析出,片状,平均粒径在1μm左右,分解温度在150~300℃范围内,分解时直接放出CO2和H2O,没有中间过程。     

矿物共沉法制取低功耗软磁铁氧体扩大试验研究

以铁屑、软锰矿和氧化锌烟灰为原料，进行了10kg/次规模的直接法制取低功耗软磁共沉粉的实验室扩大试验。实验结果表明：共沉粉杂质元素含量低，配比准确，活性好；经铁氧体工艺试验证明，所制锰锌软磁铁氧体产品的性能超过PC30，接近PC40．     

锌火法精炼加铝除铁的工业试验

针对锌精馏工艺中熔析硬锌产出率高,硬锌回收困难的问题,在理论分析的基础上进行了加铝除铁的工业试验,硬锌产出率从2.5%降至0.5%。     

Thermodynamics of solubility of Cu_2(OH)_2CO_3 in ammonia-ammonium chloride-ethylenediamine(En)-water system

In order to decrease the evaporating rate of ammonia and increase the solubility of copper in the solution,ethylenediamine was added into the ammonia-ammonium chloride system to leach the copper-containing oxide ores.The thermodynamic model was constructed and the solubility of malachite Cu2(OH)2CO3 in the ammonia-ammonium chloride-ethylenediamine(En)-water system was calculated using the exponential computation method based on both mass balance and charge balance.It is found that the solubility of copper c...     

甲基磺酸体系铅电沉积工艺研究

针对传统铅电沉积体系稳定性差、环境污染严重、腐蚀性强等问题,提出采用甲基磺酸(MSA)体系电沉积铅,考察了电流密度、铅离子浓度、MSA酸度、温度和极距对电沉积过程的影响。结果表明,在电流密度200 A/m²、铅离子浓度150 g/L、MSA酸度50 g/L、温度45 ℃和极距3.5 cm的条件下,可获得平整光亮、结构致密的铅板,纯度可达99.98%,此过程电流效率高于99%,能耗为612 kWh/t,相较于传统硅氟酸体系能耗(800 kWh/t)降低了188 kWh/t。该体系具有稳定性强、不含卤素和节能环保等优点,具有较为广泛的应用前景。