不同比容团化钽粉颗粒结构比较

利用透射电子显微镜和扫描电镜观察比较了几种不同比容团化钽粉的颗粒结构.观察发现:比容较低的钽粉其组成的一次颗粒较大,随着比容的增加,一次颗粒的平均粒径逐渐减小.但不论哪种比容的钽粉,一次颗粒间都以形成晶界形式结合,并弯曲扭转向三维空间发展,形成类似珊瑚状的多孔结构体,并具有较高的颗粒强度,且团化后的颗粒平均粒径基本相同.这种结构的团化钽粉颗粒对钽电解电容器阳极块的成型和提高电容器的容量十分有利.     

钠还原钽粉微观形态的观察及物理性能的调控

用扫描电镜和透射电镜观察了氟钽酸钾钠还原生产的钽粉的形貌和内部微观结构,它是一种以团聚体为基本粒子的粉末.通过生产工艺条件的调节和控制,生产出物理性能、电气性能适合于制作高性能的固体钽电解电容器的钽粉.     

钠还原高比容钽粉湿法提纯过程中酸洗新工艺

为了降低钽粉中各化学杂质含量,提高纯度和品质,以钠还原得到的金属钽粉(一次原生粒子)在湿法提纯处理时对不同酸洗工艺参数进行详细对比试验,根据设计的酸洗工艺路线,在不同酸液质量分数,不同酸洗时间和不同酸液配比条件下,研究同一比容钽粉(FTa-40K)对O、Fe、Ni等化学杂质的去除效果。结果表明：酸液质量分数Φ=10±0.1%的HNO₃、Φ=(1.5±0.1%)的HF,酸洗溶液体积比V(HNO₃)∶V(HF)=10.8∶1,酸洗时间150±2 min为最佳化学酸洗工艺参数,可为高比容钽粉的研发生产提供理论参考。     

冲击电流下水泥电阻和电容器的破坏特性研究

通过试验与理论分析得知:水泥电阻过冲击电流爆炸是绕线电阻引起的热效应所产生;电解电容器过冲击电流爆炸的原因则是焦耳热效应导致的内部温度升高,压强过大.试验得出了电解电容器和水泥电阻耐受冲击电流能力:5 W/0.1Ω、5 W/0.5Ω、5 W/1Ω的水泥电阻所耐受的最大冲击电流峰值分别为7.77 kA、6.20 kA和7.23 kA;25 V/470μF、16 V/1000μF、400 V/10μF的电解电容器所耐受的最大冲击电流峰值分别为2.99 kA、5.30 kA和3.08 kA.     

导电聚苯胺在铝固体电解电容器上的应用研究

采用化学氧化法,在规格为25 V/10μF的卷绕式铝电解电容器芯子中,以过硫酸铵为氧化剂合成了聚苯胺。分别考察了单体用量、氧化剂浓度以及掺杂剂种类与浓度对铝电解电容器容量和损耗的影响。结果表明:对甲苯磺酸的浓度为1 mol/L、过硫酸铵的浓度为0.7 mol/L时,所制备的铝固体电解电容器有较低的损耗和较大的容量。     

电解法制备钽粉的研究

以Ta2O5为原料,在20MPa压力下成型,1200℃烧结6h后制成阴极,以石墨为阳极,采用无水CaCh和NaCl混合熔盐体系,在800℃的温度下以及3．0V的电解电压下进行电解制取钽粉,电解时间分别为6h,12h,18h,24h,实验结果表明,随着电解时间的延长,电解产物中的氧含量逐渐降低．     

不同下电极对Sol-Gel LiTaO3薄膜性能的影响

用醇盐制备了钽酸锂(LiTaO3)溶胶,分别在Pt、ITO、TiN衬底上旋转涂胶成膜.经快速热退火后,用X射线衍射(XRD)测试了膜的结晶取向,用PLC-100铁电材料分析仪测试膜的铁电特性,用TH2818测试薄膜的介电常数及损耗.结果表明,3种衬底上制备出的薄膜在650℃均可达到充分结晶,薄膜的相对介电常数约160;在10 V时,Pt、ITO、TiN下电极上的剩余极化强度分别为8.42,5.21和5.76μC/cm2;在5V时的漏电分别为2.71×10-7,9.24×10-7和2.19×10-7A/cm2;介电损耗分别为0.02,0.18和0.31.讨论了衬底对薄膜性能影响的原因.     

银试样的电解液制备及工艺参数优化

为了有效地分析银试样的微观组织及形变织构,结合透射电镜和电子背散射衍射,制备了银试样的电解液,优化了电解抛光工艺参数.研究结果表明：利用配比为硫酸50mL＋冰乙酸115mL＋高氯酸6mL＋甲醇350mL＋草酸12g＋硫脲77g的电解液,分别在温度为0～25℃,电压为5～25V,时间为3～5min和温度为0～25℃,电压为15～20V的条件下,对试样Φ3mm×0.1mm和10mm×3mm×2mm进行电解抛光,获得了大薄区的透射电镜试样和标定率高达85%的电子背散射衍射试样.     

溶剂浸取法制备低氟高纯氧化钽研究

采用浸取剂A对工业半成品氢氧化钽进行浸取脱氟,最终制备低氟高纯氧化钽新工艺的研究。通过正交实验及其方差分析,确定了浸取脱氟的最优工艺条件为:V(浸取剂A):V(水)为1:1,浸取时间为10 min,洗涤次数为6次,煅烧温度为800℃。在该最优条件下,产品氧化钽中氟含量可控制在6 g.m-3以下。新工艺不需改变原工艺过程的工艺条件和设备,只需增加浸取洗涤装置即可。该技术具有工艺简单、投资少、成本低和节约能耗等优点。     

超级电容器在整流滤波中的应用

通过对整流滤波电流的基本要求的分析和超级电容器性能的分析,得出超级电容器也可以作为整流滤波电容器,通过2只15000ìF/10V的铝电解电容器并联和3只4.7F/2.7V超级电容器串联的对比测试、输出纹波电压波形分析,得出超级电容器可以用作整流滤波电容器,且与电解电容器相比,具有很大的性能优势、价格优势和体积优势。     

Relation between doping and texture and property of tantalum bar and wire

Relation between doping and texture and property of tantalum bar and wire was carefully investigated by optical microscope, SEM fractograph, electron microprobe analysis, density test, observation of TEM and mechanical property test at room temperature. It is illustrated that the grain of tantalum bar after sintering reduces with the increasing of dopant quantity, and the effect of dopant Ce on reduction of the grain is more obvious than that of dopant Ge, even that sintering is becoming insufficient and the density of tantalum bar tends to be lower with the increaseing of dopant Ce. The recrystallization temperature of tantalum wire increases and the grain of texture reduces with the increaseing of dopants quantity. The tensile strength of tantalum wire at room temperature increases with the increasing of dopants quantity, while its elongation decreases with the increase of dopant Ge quantity and rises with theincrease of dopant Ce quantity. And the strengthening effect of dopant Ce is clearer than that of dopant Ge.     

Optical properties and microstructure of Ta<Subscript>2</Subscript>O<Subscript>5</Subscript> thin films prepared by ion assisted electron beam evaporation

An effective method for determining the refractive index of weak absorption transparent thin films was presented, which is also applicable to other weak absorption dielectric thin films. The as-deposited Ta2O5 thin films prepared by ion assisted electron beam evaporation showed a maxima transmittance as high as 93% which was close to that of the bare substrate, and exhibited a blue shift when the substrate temperature increased from room temperature to 250 ℃. The refractive index seemed to be immune to the substrate temperature and film thickness with its value about 2.14 at incidence wavelength of 55（1 nm. The surface morphology measured by atomic force microscopy （AFM） revealed that the microstructures lead to the slim optical difference, which was the interplay of substrate temperature and assisted ion beam.     

Optical Properties and Microstructure of Ta2O5 Thin Films Prepared by Ion Assisted Electron Beam Evaporation

An effective method for determining the refractive index of weak absorption transparent thin films was presented, which is also applicable to other weak absorption dielectric thin films.The as-deposited Ta2O5 thin films prepared by ion assisted electron beam evaporation showed a maxima transmittance as high as 93% which was close to that of the bare substrate, and exhibited a blue shift when the substrate temperature increased from room temperature to 250 ℃. The refractive index seemed to be immune to the substrate temperature and film thickness with its value about 2.14 at incidence wavelength of 550 nm. The surface morphology measured by atomic force microscopy (AFM) revealed that the microstructures lead to the slim optical difference, which was the interplay of substrate temperature and assisted ion beam.     

Removal of organic matter from H2TaF7 solution by adsorption

The removal of organic matter from H2 TaFT solution by adsorption was investigated in order to reduce the carbon content in the K2TaF7 crystal. Three kinds of adsorbent, LSA-5 resin, LSA-20 resin and active carbon were applied in the fixed bed respectively. Experimental results indicate that LAS-5 resin, LAS-20 resin, the mixture of LAS-5 resin and LAS-20 resin(with volume ratio of 1：1), and the active carbon can all reduce chemical oxygen demand(COD) value of the H2TaF7 solution, and reduce consequently carbon content of K2TaF7 crystal to 0.0010%-0.0015% from 0.002 5%-0.0030%. Comparing with the others, the active carbon is an approved adsorbent whose bed volumes of effluent reaches 70. In addition, there is a linear relationship between the COD value of H2TaF7 solution and the carbon content in K2TaF7 crystal, and the carbon content in K2TaF7 crystal decreases with the decreasing of COD value of H2TaF7 solution. When the COD value of H2TaF7 solution is lower than 7 mg/L, the carbon content in K2TaF7 crystal would decrease to less than 0. 001 5%.     

Removal of organic matter from H_2TaF_7 solution by adsorption

1　INTRODUCTIONIn the process of tantalum powder production,the organic matter in H2TaF7 solution can enter in to K2TaF7 crystal by adsorbing or enwrapping inthe crystallizing step[1, 2], thus rendering conse quently a higher carbon content of the tantalumpowder as a result. Impurity elements in the tanta lum powder, such as carbon, can influence thequality of the tantalum powder enormously, espe cially to the capacitor grade tantalum powder, re ducing the break…     

Effect of doping on microstructure and technical usage property of tantalum wire

Effect of different dopants and various dopants quantity at different annealing temperatures on microstructure of tantalum wire, bending of tantalum wire after sintering and bending after pressing into tantalum powder and sintering were investigated through observation of microstructure and testing of bending of tantalum wire after sintering and bending after pressing into tantalum powder and sintering. The results show that the recrystallization temperature of tantalum wire increases and the grain of microstructure can be reduced with the increase of dopants quantity. At the same time, the effect of dopant Ce on reduction of the grain is more obvious than that of dopant Ge. The bending time of tantalum wire after sintering increases with the increase of dopant Ge or Ce quantity. Under the same condition, the bending time of tantalum wire after pressing into tantalum powder and sintering worsens with the increase of oxygen content in tantalum powder. The bending time of tantalum wire doped with Ge and Ce after pressing into tantalum powder and sintering is better than that of tantalum wire doped with Ge, while that of tantalum wire doped with Ge is better than that of pure one when oxygen content in tantalum powder is not too high.     

固体钽电解电容器频率特性研究

讨论分析了烧结型固体钽电解电容器电容量C、损耗tgδ、阻抗Z与使用频率厂的关系．实验证明，固体钽电解电容器随着厂的提高，C值相应下降，tgδ值相应上升．当频率f升到一定值时，阻抗Z出现最小值．同时还探讨了进一步改善固体钽电解电容器频率特性的方法。     

MIBK removal from aqueous solution by aeration method

In order to develop an effective MIBK removal method of H₂TaF₇ solution in tantalum extraction process, MIBK removal from aqueous solution by the aeration method was investigated by using an aeration column with the dimensions of 78 mm in inner diameter and 1 100 mm in length. The effects of aeration conditions on aerating efficiency were investigated in the ranges of temperature 303–333 K, airflow rate 50–300 L/h, volume of solution 1 600–3 200 mL. Aerating efficiency increases with the increase of temperature and airflow rate. MIBK in aqueous solution can be removed from 0.058 mol/L to 0.002 mol/L at 50°C, airflow rate 200 L/h, volume of solution 2 400 mL and aeration time 1h. The experimental results show that MIBK can be removed effectively from aqueous solution by the aeration method. Biography of the first author: LI Qing-gang, engineer, born in March 1966, majoring in extraction metallurgy of rare metals, application of membrane separation technology to metallurgical process.