C923萃取铜电解液中砷和铋的试验研究

采用C923萃取铜电解液中的砷和铋,考察萃取剂浓度、酸度、萃取时间和相比等因素对砷萃取率的影响,并探讨原液中氯离子浓度对C923萃取铋的影响。结果表明,在优化工艺条件下,砷的单级萃取率为68.41%,三级错流萃取率为97.00%。氯离子浓度为0.86 g/L时,铋的单级萃取率为95.15%。负载相用水二级错流反萃砷,总反萃率为88.20%,再用酒石酸-氢氧化钠混合液反萃铋,反萃率为81.49%。     

氢化物发生-原子荧光光谱法同时测定锡矿石中砷和锑

通常锡矿石中砷、锑含量的检测方法都是以分光光度法为主,实验以盐酸-硝酸混合酸微波消解样品,建立了氢化物发生-原子荧光光谱法测定锡矿石中砷和锑的新方法。实验表明:以8 mL盐酸-硝酸(5+3)混酸为溶剂,采用微波消解样品,在盐酸浓度约为0.96 mol/L,硫脲和抗坏血酸的质量浓度均为10 g/L时,以HCl(1+9)作为载流液,20 g/L硼氢化钾溶液为上机还原剂进行测定,以砷和锑的荧光强度与其对应的质量浓度绘制校准曲线,线性相关系数均不小于0.999 8。砷和锑的方法检出限分别为0.044 2 μg/L和0.020 4 μg/L。干扰试验表明,锡矿石样品中的共存元素不干扰测定。采用实验方法对锡矿石实际样品中砷和锑进行测定,测得结果的相对标准偏差(RSD,n=6)分别为1.1%～1.3%和0.99%～1.4%,加标回收率分别为99%～104%和98%～104%。将实验方法应用于锡矿石标准物质的测定,测定值与认定值基本一致。     

电感耦合等离子体质谱法测定高纯镍板中砷锡锑铅铋

采用10 mL硝酸(1+1)低温加热至沸溶解0.100 0 g试样,在优化仪器参数的基础上,通过选择合适的同位素以避免质谱干扰和采用标准加入法绘制校准曲线以消除基体效应,建立了电感耦合等离子体质谱法(ICP-MS)测定高纯镍板中砷、锡、锑、铅、铋的方法。各元素校准曲线的相关系数为0.999 2～0.999 9,方法检出限为0.009～0.047 μg/g。方法应用于高纯镍板实际样品分析,测得结果的相对标准偏差(RSD, n=9)为2.4%～5.4%,加标回收率为95%～106%。方法测定高纯镍板实际样品的结果与原子吸收光谱法(AAS)相吻合。     

氧化铋法从硫酸锌溶液中除氯的研究

以硫酸锌溶液为研究对象, 研究了氧化铋脱除硫酸锌溶液中氯的工艺条件, 结果表明, 较佳的工艺条件为;pH值约2.0, 50 ℃, 氧化铋用量为理论计算值的1.5倍, 反应时间2 h, 此条件下除氯后溶液中Cl含量为0.28 g/L, Bi含量为0.96 mg/L。同时研究了氯氧铋转化的工艺参数条件, 较佳的工艺条件为;NaOH用量为计算值2倍当量, 初始碱浓度1 mol/L, 反应时间4 h, 常温, 在此条件下可达到转化率93.97%、余铋浓度约2.35 mg/L的较好转化效果。进行了6周期工业实验, 与模似实验结果重现性好。本工艺操作简单, 能有效降低硫酸锌溶液中氯的浓度, 且铋损失较小。     

Luminescence and electrical properties of Eu-modified Bi0.5Na0.5TiO3 multifunctional ceramics

The Eu³⁺-modified Bi_0.5Na_0.5TiO₃ (BNT) ceramics have been fabricated by the solid-state reaction method. The impact of Eu³⁺ doping on the structure, photoluminescence, and electrical properties has been studied by XRD, SEM, PL spectra, and LCR meter. X-ray diffraction analysis reveals that the crystal structure of the samples is well matched with the trigonal perovskite, and the optimal temperature of presintering is 880°C. The Eu³⁺-doped BNT ceramics show excellent red fluorescence at 614 nm corresponding to the ⁵D₀→⁷F₂ transition of Eu³⁺ under 466 nm excitation and relatively long fluorescence lifetime. The BNT-0.02Eu ceramic density is up to 5.68 g/cm³ and the relative density is up to 94.6% with sintering temperature 1075°C. The piezoelectric constant (d₃₃) of samples has been significantly improved up to 110 pC/N by Eu³⁺ doping. The BNT-0.03Eu ceramic presintered at 880°C and sintered at 1050°C has good dielectric properties and excellent luminescence properties. Eu³⁺-doped BNT ceramics make it potential applications for novel integrated electro-optical and multifunctional devices.     

Electric field-induced irreversible relaxor to ferroelectric phase transformations in Na0.5Bi0.5TiO3-NaNbO3 ceramics

(1-x)Na_0.5Bi_0.5TiO₃-xNaNbO₃ (x = 0.02, 0.04, 0.06, and 0.08) ceramics were fabricated by solid-state reaction. High-resolution synchrotron x-ray powder diffraction (SXPD) data, coupled with macroscopic electromechanical measurements, reveal the occurrence of an electric field-induced irreversible crystallographic transformation for x = 0.02 and 0.04, from a pseudo-cubic non-ergodic relaxor to a rhombohedral or coexisting rhombohedral-tetragonal long range-ordered ferroelectric phase, respectively. The highest unipolar electrostrain, corresponding to an effective longitudinal piezoelectric strain coefficient of approximately 340 pm V⁻¹, was obtained for x = 0.04; this effect is attributed to enhanced domain switching as a result of the co-existing rhombohedral and tetragonal phases for this composition, which is critical for piezoelectric actuator applications.     

纳米ATO透明隔热涂料的制备与性能研究

以自制纳米氧化锡锑（ ATO）及其水性浆料和水性聚氨酯为原料,采用共混法制备出纳米 ATO透明隔热涂料。对纳米 ATO涂料的隔热性和透光性进行研究,结果表明：将通过溶胶 -凝胶法制备的 25 nm的 ATO粉体配制成水性浆料,与水性聚氨酯 SX-240共混制备出的纳米 ATO透明隔热涂料,具有较好的透明隔热性能。当涂膜厚度为 60 μm时,其可见光透过率（λ=600 nm）为 72.35%,平均红外透过率为 45.56%,隔热检测装置内温差达到 3~4 ℃。     

Sintering temperature effect on thermoelectric properties and microstructure of the grained Bi1.9Gd0.1Te3 compound

Elemental composition, crystal and grain structures, specific electrical resistivity, thermopower, thermal conductivity, and thermoelectric figure-of-merit of grained Bi_1.9Gd_0.1Te₃ compounds sintered at T_S = 690, 720, 735, 750, 780 and 810 K have been studied. Strong T_S – effect on the grain structure was found. Fine-grained samples with average grain size of ˜500 nm were prepared at T_S = 690, 720 and 735 K, whereas coarse-grained samples with average grain size above 1100 nm were sintered at T_S = 750, 780 and 810 K. Evaporation of Te takes place at high temperatures, which results in forming of anti-site defects of Bi in Te-sites. Electrical and thermal properties of the fine-grained and coarse-grained samples happened to be rather different. The highest value of the thermoelectric figure-of-merit equal to ˜ 0.55 was observed for the sample sintered at T_S = 750 K. This temperature corresponds to transition from the fine-grained to coarse-grained samples.     

树脂除杂技术在铜电解工业化应用研究

采用树脂对铜电解液中杂质锑和铋进行深度净化除杂的工业化应用试验,结果表明,该技术对铜电解液中杂质锑和铋的去除率均大于95%,吸附树脂锑和铋的解析率均大于95%,除杂过程中电解液中铜、镍离子含量基本不变,经过净化后的铜电解液持续返回铜电解生产系统,生产运行良好,阴极铜产品质量符合GB/T 467-2010标准中规定的Cu-CATH-1要求。     

微波消解-电感耦合等离子体原子发射光谱法测定银精矿中铅锌铜砷锑铋镉

采用盐酸-硝酸-氢氟酸并采用微波消解处理样品,高氯酸冒烟至尽干,加盐酸溶解盐类,选择Pb 220.353nm、Zn 206.200nm、Cu 327.393/Cu 324.752nm、As 193.696nm、Sb 206.836nm、Bi 190.171nm、Cd 214.440nm/Cd 226.502nm为分析谱线,使用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定铅、锌、铜、砷、锑、铋、镉,从而建立了银精矿中铅、锌、铜、砷、锑、铋、镉等杂质元素的分析方法。铅、锌、锑在0.50%~5.00%,铜、铋在0.10%~5.00%,砷在0.10%~3.00%,镉在0.050%~0.50%范围内校准曲线呈线性,线性相关系数r均大于0.9999。方法中各元素的检出限为0.001%~0.014%。实验方法用于测定两个银精矿样品中铅、锌、铜、砷、锑、铋、镉,结果的相对标准偏差(RSD,n=11)为0.74%~2.9%,并与相应的国标方法测定值相吻合(其中铅和锌采用火焰原子吸收光谱法(YS/T 445.9—2001),铜采用火焰原子吸收光谱法(YS/T 445.2—2001),砷和铋采用氢化物发生-原子荧光光谱法(YS/T 445.3—2001),锑参照采用氢化物发生-原子荧光光谱法(YS/T 445.3—2001),镉采用原子吸收光谱法(YS/T 445.8—2001))。按照实验方法测定两个银精矿样品中铅、锌、铜、砷、锑、铋、镉,并进行加标回收试验,回收率为96%~105%。