KF-NaF-AlF3 System: Liquidus Temperature and Phase Transition

JOM - The development of low-temperature aluminum electrolysis makes it possible to reduce energy consumption and greenhouse gas emissions. The KF-NaF-AlF3-based electrolyte is a promising...     

某含锌锡多金属硫化矿石锌浮选试验研究

某含锌锡多金属硫化矿石Zn、Sn、Fe、S含量分别为6.04%、1.05%、29.33%、19.08%，锌主要以铁闪锌矿、闪锌矿的形式存在，锡主要以锡石的形式存在，铁主要以黄铁矿、磁黄铁矿等形式存在，其中的金属矿物共生关系密切，相互包裹现象普遍。为确保不影响后续选锡，对锌浮选流程进行了试验研究。结果表明：矿石在磨矿细度为-0.074 mm占80%的情况下，采用预先脱硫—锌硫混浮再分离流程处理，在选择硫酸铜为锌矿物活化剂、丁基黄药为捕收剂、松醇油为起泡剂、石灰为黄铁矿抑制剂的情况下，经1段脱硫、2粗1扫锌硫混浮、1粗2精锌硫分离，锌硫分离精选尾矿与锌硫混浮扫选精矿2次精选后锌硫分离，最终获得锌精矿Zn品位47.06%、回收率90.76%，试验指标良好。     

多孔道底吹喷枪搅拌的数值模拟与强化机理分析

底吹富氧搅拌是熔池熔炼的一种关键强化技术，对品位低、杂质多的矿产资源具有很好适应性，底吹喷枪是其关键工艺设备。本文将数值模拟与数理统计相结合，建立了多孔道底吹喷枪强化搅拌的三维数学模型，并通过水力学模型实验对数学模型进行了验证。针对模型计算结果，以气泡上升时间、液体的气含率方差和平均湍流强度等为评价标准，对直管及多孔道底吹喷枪搅拌过程的混合均匀度进行对比研究。结果表明：多孔道喷枪喷吹方式在提高熔体搅动能的同时能使中上部熔体的混合更为充分，并在生产实践中取得了良好的应用效果。     

铝空气电池废电解液生产超细氢氧化铝工艺条件研究

以铝空气电池的废电解液为原料, 采用种分法生产氢氧化铝。结果表明, 当种分时间为24 h、晶种系数为2%~4%时, 可生产出超细氢氧化铝, 且粒径分布宽度窄, 阻燃性能优良, 达到HG/T4530-2013氢氧化铝阻燃剂ATH-1一等品的要求。     

Sb在高硅铝硅合金电磁分离过程中的变质行为

研究了高硅铝硅合金(45wt% Si)熔体电磁分离过程中,Sb添加量、下拉速率、温度等对分离效果的影响,对Sb在高硅铝硅合金电磁分离过程中的变质机理进行了分析。结果表明,在1500℃、下拉速率为10 μm/s时,过共晶铝硅合金熔体中加入Sb进行定向凝固后,合金部分硅铝比从11.53%降至11.21%,初晶硅富集区的硅含量从86wt%增至90wt%;当1500℃、下拉速率为40 μm/s时,合金部分硅铝比从12.56%降至12.13%,初晶硅富集区的硅含量从81wt%增至86.5wt%;加入变质剂后合金部分共晶硅相在α-Al基体中分布均匀且连续,形貌有所细化。     

Facile synthesis of IrO2 nanoparticles decorated @ WO3 as mixed oxide composite for outperformed oxygen evolution reaction

Oxygen evolution reaction (OER) electrocatalysts play the critical role in efficiency and durability for different hydrogen production systems. We have successfully synthesized the earth abundant WO₃ coupled with IrO₂ as mixed oxide composite by a facile two-step chemical method. 50% reduction in noble metal contents (IW-50) followed by two times enhancement in activity, four-folds increase in bulk mass specific activity along with the stability of mixed oxide composite as compared to state –of –the art IrO₂ catalyst are affirmed. Superior performance of mixed oxide composites are perceived due to four times increase in electrochemical surface area, reduction of Tafel slope, four-fold increase of turn over frequency, electronic distortion in Ir-4f spectrum of IW-50 along with the bridging of lattice oxygen atoms between iridium and tungsten metals. We believe that it would open up the new avenues for effective utilization of noble metal with high valence tungsten metal in corrosive environment.     

铝空气电池用6061和7075铝合金阳极电化学性能

研究了工业6061铝合金（6061）、航空7075铝合金（7075）和纯铝作为铝空气电池阳极材料的电化学性能，分析其作为阳极的可行性及适用环境。进行了阻抗、极化曲线和恒电流放电实验并进行了表面表征，计算了在40～120mA/cm²电流密度下连续恒流放电的阳极能量密度。用电子探针显微镜（EPMA）对电极表面形貌进行了研究，用波谱分析仪（WDS）进行表面分析。研究结果表明，合金元素在电池放电过程中会改变阳极的表面特性。6061中合金元素含量对电池阳极材料的性能产生了积极影响，使得合金的表面放电面积变大，放电均匀，更适合作为铝空气电池阳极材料。     

共生铅-锌混合精矿硫酸化焙烧分离铅、锌研究

采用硫酸化焙烧工艺对某共生铅-锌混合精矿进行了铅锌分离试验研究。在硫酸化焙烧过程中, 硫化铅和硫化锌与氧气反应生成硫酸铅和硫酸锌; 利用硫酸锌易溶于水、硫酸铅不溶于水的特性, 采用水浸工艺对焙烧产品进行铅、锌分离。结果表明: 在焙烧物料球团直径小于8.0 mm、空气流量1.0 L/min、焙烧温度650 ℃、焙烧时间2.5 h、硫酸钠用量2.4%、硫酸钙用量3.6%、常温常压下浸出1.5 h、浸出液固比1.5∶1, 得到了锌浸出率96.05%～96.68%、平均96.35%, 铅渣品位56.89%～57.25%、平均57.11%的指标, 铅、锌分离效果明显。     

Zn?In LDHs在Zn?Ni二次电池中的电化学性能

采用水热法制备Zn?In LDHs,并且将其作为锌镍二次电池的新型负极材料。利用扫描电镜（SEM）和X射线衍射仪（XRD）对制备的Zn?In LDHs进行了形态和微观结构的分析。通过循环伏安（CV）、Tafel极化曲线和恒电流充电放电测试研究了Zn?In LDHs作为锌镍电池负极材料的电化学性能。形貌表征发现制备的Zn?In LDHs呈现出六边形片状结构,电化学性能研究结果表明Zn?In LDHs应用到Zn–Ni二次电池中具有很好的循环可逆性能和抗腐蚀性能,恒电流充电放电测试结果分析可知,Zn?In LDHs电极表现出了较为优异的循环稳定性以及充放电特性。经过100次循环后,循环保持率可以达到92.25%。      

Spectroscopic and electrochemical investigations of lead–lead dioxide glasses and vitroceramics with applications for rechargeable lead–acid batteries

A new class of glass and vitroceramic electrodes with applications for rechargeable batteries was obtained by a melt quenching method. The structural characterization of the samples having the xPb·(100−x)PbO₂ composition, where x=0, 10, 20, 30, 40 and 50 mol% Pb, was performed by UV–vis and FTIR spectroscopies investigations.UV–vis and FTIR data reveal that the excess of lead content in the host matrix generates the transformation and/or disintegration of [PbO₆] octahedral structural units into [PbO₄] structural units or Pb²⁺ ions and non-bonding oxygen ions centers.The electrochemical performances of the glass and vitroceramics electrodes were investigated by cyclic voltammetry. The shapes of the cyclic voltammograms and redox peaks depend on the electrolyte solution concentration and the lead content in host matrix. Differences between these waves are determined by the type of electrochemically active species existing in the glass or glass ceramics. The improved performance of the vitroceramic electrodes is attributed to the presence of the lead metallic phase that seems to offer an easier route for the charge process of the electrodes. Thus, the presence of these phases generates more electrochemically active species, inhibits the secondary reactions implying PbO, takes up the ionic conduction of the larger electrolyte solution and increases the charge/discharge rate of the electrochemical processes.