亚铁离子对锌电积的影响北大核心

铁是湿法炼锌原料中含量较高且难脱除的杂质之一,硫酸锌电积液中的Fe^(2+)是电积工艺过程中重点关注的有害杂质之一。以含Fe^(2+)的硫酸锌模拟溶液为研究对象,开展锌电积的工艺试验,系统研究Fe^(2+)浓度、电流密度、极间距和电积时间对锌电积电流效率、电能消耗和电积锌形貌等的影响规律。结果表明,当电积液Fe^(2+)浓度在6 mg/L以上时,将会引起电流效率严重下降及吨锌电耗显著增加,并使阴极锌反溶;在电积液Fe^(2+)浓度为6 mg/L时,优化的工艺参数条件为:电流密度400 A/m^(2)、极间距4 cm、电积时间少于16 h,在此条件下,电流效率超过90%,吨锌电耗低于2950 kWh,同时阴极锌表面较为光滑平整。     

絮凝剂对锌电解沉积的影响研究

利用小电解实验研究了 3#絮凝剂对长周期锌电积过程和溶液COD浓度的影响.结果表明:3#絮凝剂的存在会使溶液黏度增加,易产生气泡,并能造成析出锌反溶,电流效率降低,电能消耗增加.电解液中COD浓度应控制在90 mg/L以内.可为生产上絮凝剂的使用和管理提供参考.     

氯化镍溶液中微量TBP、N-235对镍电积的影响

采用电化学测试和物理检测的方法,研究了氯化镍萃余液中,微量TBP、N-235对镍电积过程的阴极电位、阳极电位、槽压、电流效率和能耗的影响以及对阴极镍的形貌、结晶取向、内应力的影响。当电解液中同时含有TBP 和N-235时,TBP 应限制在2mg/L 以下,N-235应限制在3mg/L 以下。     

Zn(Ⅱ)-(NH4)2SO4-H2O体系中锌的电积

研究采用Zn(Ⅱ)-(NH4)2SO4-H2O体系从高氟和氯锌烟尘中回收锌新工艺的电积过程.结果表明,在阴极电流密度400A·m(-2)、温度60℃、起始Zn(2+)浓度60g·L(-1)、异极矩3cm、时间4h的最佳电积条件下,所得电锌品位>99.97%,阴极锌析出率为83.09%,电流效率92.88%,电能消耗3618kW·h.     

杂质对锌电积过程的影响及其消除

考察了有机杂质(磷酸三辛酯和异辛酸甲酯)、无机杂质氨、Pb²⁺对ZnSO₄-H₂SO₄体系中锌电积过程的影响,研究了消除有机杂质磷酸三辛酯和无机杂质Pb2+对锌电积过程影响的方法。实验结果表明: 异辛酸甲酯对锌电积过程影响较小, 而磷酸三辛酯的影响较大, 但通过活性碳吸附处理, 电积基本可以得到正常电锌。氨对锌电积过程基本无影响; Pb²⁺严重影响阴极锌质量, 而SrCO₃能有效地降低阴极锌含铅量。铅板活化后, 加入适量添加剂SrCO₃能有效地降低阴极板锌含铅量, 并在一定条件下得到0号锌。     

添加剂对膜电沉积镍效果影响的实验研究

以H_2SO_4/NiSO_4作为研究对象,采用离子膜电积技术提取金属镍。研究三种典型添加剂糖精、硫脲、十二烷基硫酸钠浓度对膜电积效果的影响。结果表明,最适糖精浓度2.0 g/L时,电流效率达到93.78%,酸回收率为36.44%,能耗为3780 kW·h/t;最适硫脲浓度在0.05 g/L时,电流效率达到92.34%,酸回收率为34.89%,能耗为4 006 kW·h/t;最适十二烷基硫酸钠浓度在0.05 g/L时,电流效率达到89.01%,酸回收率为31.09%,能耗为4 800 kW·h/t,此时电镍平整光亮,晶粒结合紧密,气孔皲裂较少,形貌质量良好。     

硫酸锌电解液中微量钉、钛对电积锌过程的影响

本文通过电化学测试和物理检测的方法,研究在硫酸锌电解液中钌、钛的存在对电积锌过程的影响。极化曲线表明溶液中有1mg/1钌时,极化电流明显升高,但溶液中有10mg/1钛时,极化电流尚未见明显变化。恒电流电解实验表明溶液中有5mg/1钌时,电流效率由92.2%下降到58.2%。锌沉积物中大约有0.01%的钌。适量钛的存在,电流效率还有所提高。实验还表明溶液中锌离子对钌的影响有抑制作用。溶液中钌、钛对锌沉积物的形貌和结晶取向均有影响。     

碱浸-电解锌工艺中杂质对锌电积的影响

针对碱浸-电解锌工艺,系统地研究杂质元素对锌电积过程的影响.分析表明,以满足生产四级锌粉标准(GB/T6890-2000)为限,电解液中可接受的杂质浓度范围为氯≤20g/L、次氯酸≤1‰(体积分数)、钨≤800mg/L、锡≤600mg/L、钼≤50mg/L.     

铜电解液电积脱铜制备高纯阴极铜

利用电积法制备高纯阴极铜, 研究了添加剂、电解液温度、电流密度以及Cu²⁺浓度对电积法脱铜制备高纯阴极铜质量的影响。当添加剂(骨胶: 明胶: 硫脲质量比为6∶4∶5)用量为40 mg/L, 电解液温度为55 ℃, 电流密度为200 A/m², 电解液中Cu²⁺浓度从48.78 g/L降至31.71 g/L时, 电积脱铜得到的阴极铜质量达到了高纯阴极铜标准(GB/T 467-1997); 其电流效率达到99.19%, 高纯阴极铜产率达到38.09%。电积脱铜制备高纯阴极铜不仅增加了阴极铜产量, 而且可大大减少电积时黑铜板和黑铜粉。     

锌电积溶液深度脱锑

采用硫酸铜添加剂对锌电积溶液进行深度脱锑。在锌电积溶液锑浓度为1.58 mg/L时, 只需在锌电积溶液净化工序末端添加0.025 g/L以上硫酸铜, 锌粉用量1 g/L, 反应时间为1 h, 反应温度为65 ℃, 锌电积溶液锑含量将降至0.1 mg/L以下, 满足锌电积液质量要求; 深度脱锑的同时, 其它杂质元素的含量也有所降低。若初始电积液锑浓度增加, 需相应增加硫酸铜用量, 方可达到净除锑的目的。     

锌电解自动剥板机在云南某冶炼厂的应用

大极板锌电积生产工艺与现有小极板电积工艺相比,具有电耗低、自动化水平高、操作环境好等优点,代表湿法炼锌工艺的发展方向。重点介绍了自动剥板系统在云南某冶炼厂的使用情况,以及进口与国产设备实际使用中的优缺点:进口设备在前端电解工艺参数较好的时候,剥离效率较高,而国产设备对前端电解工艺适应性好,自动化程度、可靠性更强。     

Electrowinning of zinc from sulphate solutions in the presence of perfluoroglutaric acid

This paper deals with the effect of perfluoroglutaric acid in the presence and absence of antimony(III) on the cathodic current efficiency, energy consumption and polarisation behaviour of the cathode during electrowinning of zinc from acidic sulphate solutions. Surface morphologies and crystallographic orientations of the zinc deposits were also examined using scanning electron microscopy and X-ray diffraction analysis. Perfluoroglutaric acid was found to increase the current efficiency, decrease the energy consumption and produce better surface morphologies. Voltammetric studies revealed that perfluoroglutaric acid when present in the solution depolarised the cathode which was also reflected in the deposit morphologies showing bigger size crystal planes than the deposit obtained in its absence. Presence of antimony(III) in the solution deteriorated the deposit quality and resulted in corrugated deposits at higher concentrations.     

喷射床电解槽在锌电积中的应用

通过对湿法炼锌中锌电解沉积过程的具体分析, 认为喷射床电解槽在电流效率、能耗和投资费用等方面比原有传统的电解槽有很强的优势。着重讨论了喷射床这种新型三维颗粒电极电解池的构造、特征、相关理论和研究状况。     

基于锌负极的混合水溶液电池的构建及电化学性能研究

向电解液中加入明胶、硫脲和硼酸, 采用电解的方法制备了锌箔。采用X射线衍射仪和扫描电子显微镜对商业锌箔和自制锌箔进行了结构和形貌表征, 研究了2种锌箔在1 mol/L ZnSO₄和2 mol/L Li₂SO₄混合电解液中的耐腐蚀性能, 考察了2种锌箔在混合水溶液电池中的循环性能及浮充性能。结果表明, 自制锌箔表面平整光滑, 其腐蚀电流为79.926 μA, 电池循环100次后, 容量保持率高达86.1%, 且高温浮充24 h, 浮充电流密度仅为3.99 mA/g, 自制锌箔耐腐蚀性能良好。     

热镀锌渣碱性电解法制备锌粉

以热镀锌渣为原料，通过碱性电解法制备锌粉。锌粉的比表面积为3．9m^2g^-1，含锌为98％，杂质（Ca，Pb，Cu，Fe）含量为0．23％。随着电解温度的升高，锌粉分别以枝晶状、节瘤状析出，锌粉的缓腐蚀能力提高。不加添加剂制备的锌粉为由片状晶粒组成的枝晶，加Tween 60为层片状晶粒组成的枝晶，加十二烷基苯磺酸钠为由石头状晶粒组成的枝晶。     

Einsatz von Bleilegierungsanoden in Metallgewinnungselektrolysen

In metal electrowinning processes different lead alloys are used as insoluble anodes. Demands on the anode material are low corrosion rates for a long life time, low oxygen overvoltage to minimize the specific energy consumption and good mechanical stability. In recent years, mainly the production processes and the concentration range of the alloying elements were optimized to improve the anode properties. Steps of this development were transferred from investigations to optimize the grid materials for lead SLI accumulators. In copper electrowinning the PbSb anodes used in the past have been replaced to a large extent by PbSnCa alloys. These anodes have relatively good mechanical properties and a sufficient corrosion rate, but a relatively high anode potential. Until now, in zinc electrowinning anodes made of PbAg alloys are used.     

pH对臭氧氧化深度去除湿法炼锌溶液中铁的影响

铁是湿法炼锌过程中的有害杂质成分,必须在锌电积前深度去除。本文研究了在臭氧氧化条件下pH对ZnSO4溶液中除铁性能的影响。结果表明,铁的去除率和锌的损失率随pH的升高而增大,在pH=4.5时,铁去除率达到99.98%,渣中Zn和Fe含量分别为1.52%和34.61%,沉淀渣主要是由FeOOH和ZnSO4?XH2O组成。随着pH值的增加,铁沉淀物颗粒趋于团聚,粒径显著增大,沉淀的可过滤性提高。锌通过包裹在沉淀物的晶格中或被沉淀物所吸附而损失在铁沉淀物中。臭氧氧化过程中Fe3+/Fe2+比值及臭氧消耗量随pH的增加而增加,从而导致ZnSO4溶液的电位值减小。     

Anode effects in electrowinning

In traditional electrowinning operations, metal particles from commercial insoluble anodes flake off the immersed surfaces under high current densities and thus become occluded on the adjacent cathode surface thereby impairing the cathode product quality and market grade. This results in an undersirable physical appearance of the cathode due to irregular protrusions which impede subsequent material handling operations such as packaging, weighing and shipping. The paper serves to highlight the existing problems inherent with permanent anodes and suggests possible areas for further research and development studies.At present, permanent anodes are employed in the worldwide electrolytic industry for the recovery of base metals such as copper, nickel, cobalt, and zinc while smaller scale operations exist to recover precious metals such as gold and silver from leach solutions. The coupling of solvent extraction with electrowinning technology (SX-EW) is now a widespread practice. Unfortunately, the usage of permanent anodes has the disadvantages of ongoing maintenance costs to clean the anode surfaces and refurbish the wetted area, results in lower anode useful life, the expense of anode replacement, lower current efficiency, higher power consumption as compared to electrorefining, and inferior cathode quality which becomes contaminated due to deterioration of the metal or metal alloy used to fabricate the insoluble anodes.Apart from improvements in productivity and cathode product quality, and lower labour requirements, the driving force to remedy present electrowinning performance is mainly a reduction in energy. Another associated problem area is the usage of mother blanks fabricated from either aluminum, copper, titanium, or stainless steel as employed to enable full deposit stripping. It is recognized that the construction of the different hanger bars used to support both permanent anodes and mother blanks presents another problem area for study which is addressed within the paper. The writers advocate investigations to improve non-ferrous metal stripping practice, increase current efficiency and extend the useful life of permanent electrodes. The anticipated improvement in full plate cathode chemical and physical quality will benefit downstream operations such as copper wirerod production and subsequent fine wire drawing.