新型抑制剂对黄铜矿与方铅矿浮选分离的影响及其机理研究

针对硫化铜铅混合精矿难分离,剧毒抑制剂应用广泛的现状,研发了新型无毒抑制剂YZJ(亚硫酸钠+硅酸钠+CMC)。通过单矿物浮选试验对混浮-脱药-抑制分离的工艺,采用丁基黄药为混合浮选的捕收剂,Na2S为脱药剂,YZJ为抑制剂,Z200为分离的捕收剂对铜铅分离作业的浮选进行了试验研究。并通过红外光谱分析、吸附量测定以及电化学测试,考察了黄铜矿和方铅矿与不同药剂的作用机理。结果表明,Z200对黄铜矿具有良好的选择性,可以作为黄铜矿和方铅矿分离流程的捕收剂使用,新型抑制剂能够在铜铅分离中有效地抑制方铅矿,能够高效实现铜铅分离。     

等离子体渗氮时间对304不锈钢腐蚀行为的影响研究

为改善304不锈钢在Cl-环境中的局部腐蚀性能,采用热丝增强等离子体非平衡磁控溅射技术,对其进行离子渗氮。利用扫描电镜、X射线衍射仪及电化学工作站,对不同渗氮时间下304不锈钢渗氮层的组织、结构及耐蚀性能进行了研究,并讨论了相关的腐蚀过程及耐蚀机制。结果表明,等离子体渗氮对304不锈钢的耐蚀性能有显著影响。经2 h渗氮后,304不锈钢的腐蚀电位从-257提高至-128 mV,阻抗模值较基体提高了3个数量级。而腐蚀电流密度则从7.94×10^-7降低至5.21×10^-8A/cm²,腐蚀失重从837.65 g/m²·a^-1降至159.46 g/m2·a^-1,不锈钢的耐蚀性能得到显著提高。然而,当渗氮时间延长至4 h时,由于多余的N原子与Fe原子相结合形成Fe₃N。γ_N相与Fe₃N相构成电偶,形成腐蚀微电池,使腐蚀电位显著降低,腐蚀电流密度和腐蚀失重明显增加,从而降低了不锈钢的耐蚀性能。在本实验中,渗氮2 h的304不锈钢在含Cl^-溶液中的耐蚀性最佳。     

Dual carbon source method to fabricate hierarchical porous carbon with three-dimensional interconnected network structure toward advanced energy storage device

Selective fabrication of carbon materials with developed specific surface area and hierarchical porous structure is essential for high-performance carbon-based supercapacitors. Direct carbonization of organic acid salts represents a strategy that can produce porous carbon with high specific surface area, but it is still hindered by low carbon yield, impeding its large-scale application. Herein, a biomass-derived hierarchical porous carbon with large specific surface area is prepared via a facile one-pot calcination method. The optimal SCPC-4 sample presents three-dimensional interconnected network structure and plentiful heteroatom content. Hence, it delivers a large specific capacitance of 321 F g^?1 at a current density of 1 A g^?1, and negligible capacitance loss after 10,000 cycles at 10 A g^?1. In addition, the assembled SCPC-4 based symmetric supercapacitor exhibits an energy density of 21.2 Wh kg^?1 at a power density of 900 W kg^?1. This cost-effective binary biomass carbon source route provides a great possibility for the mass production of high-yield porous carbon materials.     

Interdiffusion at electrochemical interfaces between yttria-stabilized zirconia and doped ceria

Integration of doped ceria into fuel electrode-supported solid oxide cells is challenging due to high sintering temperatures leading to undesirable interdiffusion between the layers.We investigate the influence of the dopant in ceria X_0.1Ce_0.9O_1.95 (10XDC, X = Y, Gd or Sm) on the interdiffusion with yttria-stabilized zirconia (8YSZ). Powder mixtures of 8YSZ and 10XDC were sintered at temperatures between 1000 and 1400 °C to quantify the phase formation. Interdiffusion in layered systems sintered at 1400 °C was investigated by SEM. Symmetrical Ni-10XDC cells with an 8YSZ electrolyte were analyzed using impedance spectroscopy. Despite small differences in the interdiffusion behavior, different dopants do not lead to significant changes in the cell impedance.Notably, the presence of NiO in the fuel electrode leads to enhanced interdiffusion kinetics of 10XDC with 8YSZ and the formation of porosity at the electrolyte interface. The detrimental influence of these microstructural changes on the electrode performance was investigated.     

磨矿介质对方铅矿浮选影响的电化学机制研究北大核心

磨矿作业对硫化矿浮选有重要影响。以方铅矿为研究对象、以电化学分析为主要手段,研究了钢、不锈钢、陶瓷三种磨矿介质对方铅矿浮选的影响机制。三种磨矿介质对应的回收率分别为:钢79.71%、不锈钢81.62%、陶瓷83.43%,磨矿介质的电化学活性越高方铅矿可浮性越差。分析结果表明,在与方铅矿组合的电偶中,介质钢和不锈钢都充当阳极发生氧化反应,陶瓷介质中则是方铅矿作为阳极发生氧化反应,这导致陶瓷介质磨矿时方铅矿表面疏水物质S 0的含量远高于钢和不锈钢介质磨矿;另外,电化学活性越高,磨矿介质与方铅矿的伽伐尼电偶作用造成的电化学腐蚀越强,生成铁的氧化物和氢氧化物等亲水物质对方铅矿的迁移罩盖越强,可浮性也就更差。     

Methodology of the electrochemical hydrogen permeation test: A parametric evaluation

In this study, a methodological approach is pursued to gain an elaborated understanding concerning the Devanathan-Stachurski technique. Different experimental test parameters such as the polarization potential at the exit side, the applied charging current density, the electrolyte, the oxygen content, the sample roughness and the electrolyte composition, are modified to evaluate their influence. It is found that the surface roughness and possible contaminations from of the electrolyte are of high importance for realizing a stable entrance surface state. Furthermore, the partial transient procedure can be used for determining a diffusion coefficient which approaches the lattice diffusion coefficient.