电氧化法地下卤水提溴探究及条件优化

通过设计包含三电极体系的电解槽,并严格控制工作电极电位,提出以电氧化的方法进行地下卤水中溴资源的选择性提取。对电氧化法地下卤水提溴的技术可行性、反应动力学模型、共存Cl^-和阳极液初始pH的影响以及最佳操作时间展开分析讨论。结果表明：电氧化法用于地下卤水提溴具备技术可行性,且反应遵循二级反应动力学模型。随共存Cl^-浓度的增加,Br^-的电氧化反应速率常数先增大后减小,Cl^-对反应可产生促进与抑制的双重作用：促进作用来源于随Cl^-浓度升高而增大的溶液总电导率,抑制作用来源于Cl^-与Br^-在石墨电极表面的竞争吸附;单位能耗随Cl^-浓度的增大而减小,电流效率相对不受影响。随阳极液初始pH的减小,Br^-的电氧化反应速率常数逐渐增大,电流效率与单位能耗相对不受影响。随电氧化操作时间的延长,Br₂提取率的增长速率逐渐降低,电流效率不断降低,单位能耗不断升高的同时其增长速率也不断增大;6~10 h为推荐的最佳的操作时间。     

NH4Cl溶液浓度对Incoloy 825合金腐蚀行为的影响

通过电化学阻抗技术、极化曲线和浸泡腐蚀实验对Incoloy 825合金在不同浓度NH₄Cl溶液中的腐蚀行为进行了研究。研究结果表明：开路电位随着浓度的升高而负移,腐蚀倾向增大;采用等效电路R_S（Q₁R₁）（Q_dlR_t）对电化学阻抗谱进行拟合,电荷转移电阻R_t随浓度增加而减小,Incoloy 825合金的维钝电流密度和腐蚀速率随浓度的增加而增大;825合金的腐蚀形貌主要为局部腐蚀,点蚀的密集度和大小随浓度的增加而增大;EDS结果表明Cl^-参与了电化学反应过程。     

微通道内离子液体/乙醇混合溶液吸收CO2的传质特性

采用高速摄像仪对微通道内离子液体/乙醇混合溶液吸收CO₂的传质行为进行了实验研究。考察了弹状流型下气液两相流量比和离子液体浓度对液侧体积传质系数k_La和液侧传质系数k_L的影响。当离子液体浓度不变时,k_La、k_L均随气液流量比的升高而增大并逐渐趋于恒定。当液相流量不变时,对于不同浓度的离子液体溶液,液侧体积传质系数k_La和液侧传质系数k_L随气液流量比的变化曲线出现了交叉点。在交叉点之前,k_La和k_L均随着离子液体浓度的增大而减小;在交叉点之后,k_La和k_L均随着离子液体浓度的增大而增大。提出了用于预测液侧体积传质系数k_La的新的量纲1经验关联式,预测效果良好。     

异丙醇汽液界面特性的平衡分子动力学模拟

采用OPLS刚性联合原子模型,以异丙醇分子的作用位点为统计对象,对异丙醇的汽液界面特性进行了平衡分子动力学模拟研究。模拟结果表明,随着温度的升高,液相主体密度减小,汽相主体密度增大,汽液界面厚度增大;截断半径和薄片数对汽相主体密度体、液相主体密度及汽液界面厚度的影响不大;随着模拟分子数的增大,汽液界面厚度有所增大。     

气-液两相降膜流动及传质过程的CFD研究

利用VOF法建立了考虑表面张力动量源项、气液相间摩擦力动量源项以及相问传质源项的CFD计算模型,定量描述了气．液两相逆流降膜传质过程。根据CFD模型,计算了不同液相进口浓度和不同气相流量条件下,异丙醇稀溶液的解吸过程,模拟得到的液相出口浓度与实验数据吻合很好。相界面处的浓度分布表明。随自由表面波动,界面浓度会发生剧烈脉动。液相总传质系数增强因子R的实验值与CFD模拟均表明,即使在很小的传质推动力下R也大于1。由于CFD模型不考虑Rayleigh-Benard-Maragoni效应,则这种现象,可解释为界面波动对传质增强的结果。这也证明增强界面波动是一种强化传质分离过程的有效途径。     

微通道内离子液体/乙醇混合溶液吸收CO_2的传质特性

采用高速摄像仪对微通道内离子液体/乙醇混合溶液吸收CO_2的传质行为进行了实验研究。考察了弹状流型下气液两相流量比和离子液体浓度对液侧体积传质系数kLa和液侧传质系数kL的影响。当离子液体浓度不变时,kLa、kL均随气液流量比的升高而增大并逐渐趋于恒定。当液相流量不变时,对于不同浓度的离子液体溶液,液侧体积传质系数kLa和液侧传质系数kL随气液流量比的变化曲线出现了交叉点。在交叉点之前,kLa和kL均随着离子液体浓度的增大而减小;在交叉点之后,kLa和kL均随着离子液体浓度的增大而增大。提出了用于预测液侧体积传质系数kLa的新的量纲1经验关联式,预测效果良好。     

水及其表面活性剂体系汽—液界面行为的分子动力学模拟

采用分子动力学模拟技术,对水及其表面活性剂体系的汽—液界面行为进行了研究。模拟结果表明,随着温度的升高,纯水体系液相主体密度降低,气—液界面厚度增大,界面张力逐渐减小;水—十二烷基硫酸钠体系与纯水体系相比,汽—液界面厚度明显增大,汽—液界面张力明显减小,其随温度的变化规律和纯水体系一致。     

文丘里洗涤器内硫化氢气体碱液吸收过程的CFD模拟

采用双流体模型、RNG k-?湍流模型和组分输运模型对不同工况下自吸式文丘里洗涤器内Na OH溶液洗消H2S气体的引射能力、气液混合度和洗涤效率进行数值模拟,对引射量的模拟结果进行了实验验证.结果表明,在气液流动过程中,随气速增大,自吸式文丘里洗涤器引射量增大,洗涤器扩大段内液相径向分布均匀性减弱,液相倾向于贴壁流动.距喉部越远,气液速度越低,液相径向分散越均匀.在H2S碱液吸收过程中,气液相间化学反应主要集中于喉部至喉部上方扩大段长度1/5区域内,反应速率随距喉部距离增加先升高后降低.最大反应速率在喉部上方扩大段长度5%处.随气速增大,扩大段内气液相间化学反应速率提高,洗涤器出口处H2S浓度降低,洗涤效率增大,洗涤时间缩短.     

改良型CO2湿壁塔内气液两相流动规律及传质特性

基于Fluent软件，采用层流模型、VOF模型及非稳态类型，模拟基准湿壁塔和改良型湿壁塔的气液两相流场，分析稳定液膜边界气液两相流场对传质过程的影响。结果表明，随液相入口流量的增大，在稳定液膜边界气相涡旋运动逐渐增强，气液两相混合程度加强，利于改良型湿壁塔的气液两相传质。在一定气相入口流量范围内，随气相入口流量的增大，液膜界面涡旋运动增强，气液两相混合程度加强，利于改良型湿壁塔的气液两相传质；气相入口流量不宜过大，否则导致液相不能沿湿壁柱向下流动形成稳定的液膜，不利于传质。改良型湿壁塔的变径结构和气体挡板均利于气液两相混合，利于传质。改良型湿壁塔的传质过程在液膜边界发生，随液相入口流量的增大液膜厚度增加，液膜表面积增大，有效传质面积增大，利于气液两相传质。通过对比基准湿壁塔和改良型湿壁塔的气液两相流场，改良型湿壁塔内气液两相混合程度加强，更利于传质。     

并行微通道内气液相分配规律

微反应器的集成放大对于微化工技术的工业应用具有重要意义。利用高速摄像仪对4个并行微通道内气液两相流动状况及相分配规律进行了研究,考察了气液两相流量及液相黏度对两相分布均匀性的影响。实验所用液相为含0.3%表面活性剂十二烷基硫酸钠（SDS）的蒸馏水-甘油溶液,气相为氮气（N₂）。实验观察到了6种典型的两相流型。对各支通道均为弹状流情况下气泡长度和气泡速度的分布规律进行了研究。在一定气相流率下,各支通道气泡长度的相对标准偏差随液相流率的增大而增大,气泡速度的相对标准偏差值随液相流率的增大先升高到一定值然后逐渐减小。气相分配不均匀性随液相流率和黏度的增大而增大,液相分配不均匀性随液相黏度的增大而减小,气相流率的变化对于两相分布影响不明显。研究结果有助于并行微通道的结构设计与优化,以实现更为均匀的气液两相流动分配。     

高浓度氯离子环境中铜合金缓蚀的电化学研究

应用线性电位扫描(LSV)和Tafel实验等电化学测试技术,研究了苯并三氮唑(BTA)浓度、缓蚀剂的复配、温度对铜合金在高浓度氯离子(25%氯化钙溶液)环境中腐蚀行为的影响。结果表明:缓蚀剂浓度改变将引起缓蚀效果的变化,BTA浓度较低时,铜合金腐蚀电位随缓蚀剂浓度增大而升高,腐蚀速率降低;BTA浓度超过0.2%后,铜合金腐蚀电位和腐蚀速率趋于稳定;NaNO2、Na2MoO4、(NH4)2MoO4等缓蚀剂与BTA复配,对改善缓蚀效果有一定作用;温度对缓蚀效果有重要影响,铜合金在高浓度氯离子溶液中的腐蚀速率随温度的升高而加快,缓蚀剂的缓蚀效果随温度的升高而降低。     

Amikacin disulfate: an aminoglycoside antibiotic drug as a corrosion inhibitor for copper in 1 M nitric acid medium

The effect of commercially available pharmaceutically active compound amikacin disulfate (AMK) against the corrosion of copper in 1 M HNO₃ solution was investigated using Tafel polarization, electrochemical impedance spectroscopy (EIS), and weight loss techniques. The results show that inhibition efficiency (IE %) increases with increasing inhibitor concentration from 0.1 to 1.0 mM. Increasing the temperature increased the corrosion rate, and results decreased the inhibition efficiency. The adsorption of inhibitor obeyed Langmuir adsorption isotherm model via physisorption mechanism. EIS technique exhibits one capacitive loop, indicating that the corrosion reaction is controlled by charge transfer process. Polarization measurements showed that the AMK is mixed-type inhibitor. The surface morphologies were studied by scanning electron microscopy and atomic force microscopic techniques. The corrosion mechanism were explained by Fourier transform infrared spectroscopy.     

铜表面化学蚀刻的研究

应用电化学反应原理和配位场理论,对以硫代硫酸钠和碳酸氢铵组成的蚀刻溶液的铜表面化学蚀刻原理进行了分析,认为:铜被硫代硫酸钠氧化为铜离子,铜离子与碳酸氢铵提供的氨分子迅速形成稳定的铜氨络离子。研究了各组分浓度、温度对蚀刻速率的影响作用,并进行了蚀刻溶液对钢设备的腐蚀性能研究。结果表明:随着溶液中硫代硫酸钠和碳酸氢铵浓度的增加,蚀刻速率增大,而碳酸氢铵的浓度受硫代硫酸钠浓度的限制,蚀刻溶液对钢设备没有腐蚀作用。     

The inhibiting effect of 3-methyl 1,2,4-triazole 5-thione on corrosion of copper in 3% NaCl in presence of sulphide

The effect of sulphide addition to the corrosion of copper in 3% NaCl was studied. The concentration of sulphide was remained rather low, up to 10 ppm. The effect of sulphide to copper corrosion is controversial in the literature and worth to verify by means of various experimental techniques. The polarization curves, plotted from a potential close to the open circuit one to negative or to positive direction indicated a decrease of corrosion current density, explained in the literature by the protective effect of CuS. In contrast, a quartz crystal microbalance, with electro-deposited copper indicated the increase of corrosion rate with increasing sulphide ion concentration. The EIS measurements showed also an acceleration of corrosion rate by addition of sulphide ions in sodium chloride solution. It is concluded that the presence of sulphide ions in the seawater accelerates the corrosion of copper. To protect the copper structure from the corrosion in presence of sulphide as pollutants, the anticorrosion effect of a new molecule, 3-methyl 1,2,4-triazole 5-thione was examined. The action of this molecule results in the reduction of the both anodic and cathodic current density, and its inhibiting efficiency reached a value of 90% at the concentration of 10 mM.     

Corrosion protection of copper by polyaminophenol films

The anticorrosion behaviour of polyaminophenol (PAP) films has been investigated in aqueous 0.5 M NaCl solution using electrochemical impedance spectroscopy and weight loss measurements. The effect of triazole compounds on the protection behaviour of the polymer was also examined. The polymer is obtained by in situ electropolymerization of 2-aminophenol monomer in alkaline hydroalcoholic solution. The results show that the polymer film reduces the corrosion of copper and that the electropolymerization in the presence of the azole compounds further increases the protective character of the coating. The polymer copper/solution interface is well described by an electrical equivalent circuit reflecting the behaviour typical of a porous film.     

Experimental and theoretical studies of anti-ulcer drugs with benzimidazole rings as corrosion inhibitor for copper in 1 M nitric acid medium

The adsorption effect of esomeprazole (ESP) and lansoprazole (LP) on corrosion behavior of copper in 1 M HNO₃ solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The experimental results indicate that both ESP and LP inhibited the corrosion of copper in nitric acid solution and the inhibition efficiency increased as the concentration of the compounds increased. EIS measurements confirmed that the charge transfer resistance increases on increasing the inhibitor concentration. Polarization measurements showed that the inhibitors are of mixed type. From the weight loss measurements, the inhibition efficiency of the inhibitors was found to vary with concentration, immersion time, and temperature. The adsorption of inhibitors on the copper surface follows Langmuir isotherm. The surface morphology was examined by scanning electron microscope and atomic force microscope. Further, the computational calculations are performed to find a relation between their electronic and structural properties.     

Application of electrochemical noise to evaluate outdoor atmospheric corrosion of copper after relatively short exposure periods

This study focused on the application of electrochemical noise to assess the protection level of corrosion products formed on copper during relatively short exposure time in different outdoor atmospheres. Electrochemical noise, cathodic reduction measurements and gravimetric (mass loss) analysis were applied to copper samples exposed at urban and rural/industrial areas in Cuba for 4 months. Measurements of Electrochemical current noise indicated that the poorest protective corrosion products were formed on samples exposed to atmospheres with high concentration of H₂S which agreed with the corrosion rate determined by mass loss and electrochemical chronopotentiometry (cathodic reduction). The electrochemical noise methodology proposed in this work showed acceptable and reproducible results by using an electrochemical cell in which the electrolyte was formed by a distilled-water wetted cloth in contact with the compounds present on a corroded metallic surface. This methodology indicated that the corrosion protection level of the corrosion products formed on copper is related to the corrosivity of the atmosphere.     

用盐湖水氰化堆浸含铜金矿石的实践

通过ＡＢ两个矿样的堆浸试验，提出了在可溶性盐总量（ＴＤＳ）高的水中，溶解氧浓度与金相对溶解速度随水中含盐量变化的回归方程．从理论上分析ＮａＣＮ、ＮａＯＨ耗量高的原因．用高ＴＤＳ水堆浸时，浸出周期长、结盐严重，炭对金的吸附率下降，炭再生的效果差，设备腐蚀严重．矿石中的钢不仅影响金的浸出，还影响金在活性炭上的吸附。对含铜高的载金炭，应先在室温下的ＮａＣＮ溶液除铜．文中还提出了改善高ＴＤＳ水堆浸提金效果的措施。     

Influence of sulphide ions on the cathodic behaviour of copper in 0.1 M borax solution

The presence of sulphide ions in solution greatly influences the cathodic behaviour of copper in borax solutions (pH9.2), even when this contaminant is in low concentration. Cyclic voltammograms, polarisation curves and Tafel plots are compared for polluted and unpolluted solutions. Prereduced and aged copper electrodes are investigated. The presence of sulphide ions in solution increases the rate of oxygen reduction on copper, thus having a detrimental effect on the global corrosion process. The transformation of the surface film into one with better conductive properties is suggested.