钇、钪分离工艺的新进展

本文简要介绍中国科学院长春应用化学研究所近年来在钇、钪分离工艺研究方面的新进展。     

钪系阴极基体的研究

采用氧化钪与钨机械混合、氧化钨与钪盐水溶液固液掺杂法制备了氧化钪-钨基体，采用扫描电镜及原位俄歇电子能谱方法研究了基体中钪的分布及阴极基体的抗离子轰击性能。结果表明，采用液固法制备的烧结体，氧化钪分布均匀，这样的结构有利于钪的扩散和补充，原位俄歇轰击实验结果表明，阴极基体具有良好的耐高温和耐离子轰击性。     

含钪Al-Cu合金的显微组织

采用硬度测试、金相观察、扫描电镜和透射电镜测试及能谱分析的方法,研究了稀土元素Sc含量对Al-4Cu合金组织的影响.结果表明:Sc可显著细化Al-Cu合金的网胞组织,减小枝晶间距,细化合金的晶粒组织,提高合金的显微硬度,提高幅度最约70%;将Sc添加到Al-4Cu合金中,当w(Sc)≈0.3%时,Sc除部分固溶于基体外,大部分与Al形成Al3Sc相,其与基体的共格或半共格界面促进了θ′(CuAl2)的析出;当w(Sc)＞0.3%时,Sc除部分固溶和形成Al3Sc外,还与Al、Cu元素作用形成W(AlCuSc)相,降低Cu在α(Al)中的固溶度,减少Al2Cu(θ′)相的生成,从而降低了合金的性能.     

含钪Al-Cu-Li合金的形变时效研究

通过显微组织观察和室温拉伸试验，研究了形变时效对含钪Al-Cu-Li合金组织和拉伸性能的影响。结果表明，时效前的预变形能促进T1(Al2CuLi)相弥散细小的析出，显著提高合金的强度，使时效峰值提前。合金的强度随预变形量的增大而升高，但预变形量过大，不利于T1相的析出形态和分布，影响合金的性能。在本试验条件下，该合金的最佳预变形量为3．5％。     

从高纯氧化钪中分离微量铁、锆的研究

选用D235阴离子交换树脂和P350萃淋树脂分别吸附分离99．95％Sc2O3中的微量铁与锆。对吸附酸度、分离介质、洗脱液用量等条件进行了筛选试验。在选定的条件下，微量铁与锆的分离结果令人满意。本方法可在提取高纯Sc2O3工艺中应用。     

Effects of scandium on hypoeutectic aluminium copper microstructures under low solidification rate conditions

This work addresses the microstructures and mechanical properties of Al-4.5 wt-% Cu alloys containing 0.1, 0.2 and 0.4 wt-% Sc that were solidified under low cooling rate conditions (0.01, 0.08, 0.3 and 0.8°C s^?1) and then heat treated. The solidification and heat treatment processes were carried out in a differential scanning calorimeter. Two different approaches were used for heat treatment. The first approach, involved the traditional heat treatment sequences including solutionising for 18.5 h at 535°C then quenching, followed by aging at 240°C for 2 h. The second approach consisted of direct aging of the as-solidified samples. Under low solidification rate conditions, Sc is found to modify the grain morphology from elongated dendrites to equiaxed structures but is neither a grain refiner nor a strengthener. Indeed, much of it is tied up with Cu in the form of the intermetallic W-phase. Consequently, there appears to be no benefit to adding Sc, in the hypoeutectic composition, to Al-4.5 wt-% Cu if the traditional heat treatment route is followed. However, a minor improvement in hardness is observed upon aging immediately after solidification when 0.4 wt-% Sc is added, owing to excess Sc dissolved in the matrix and not precipitating as the W-phase.     

High‐performance polymer‐supported extractants with phosphonate ligands for scandium(III) separation

As the market demand for scandium has grown, a great deal of interest has been generated in its recovery. To substantially simplify the process and provide a green alternative for scandium separation, novel polymer‐supported extractants containing di(2‐ethylhexyl) phosphonate and bis(2,4,4‐trimethylpentyl) phosphonate, [D201][DEHP] and [D201][C272] are proposed because they demonstrate improved adsorption capacity and selectivity toward scandium(III). Scandium(III) adsorption is significantly affected by the solution pH, with the maximum adsorption occurring at a pH of approximately 0.78. The batch adsorption data fit well with the Langmuir isotherm and pseudo‐second‐order kinetic models. A combination of the Fourier transform infrared and XPS spectra suggest that the complexation of oxygen atoms in phosphate groups with scandium(III) is the predominant adsorption mechanism. Additionally, the two resins were used to recover scandium from leaching liquor of nickel laterite ore. [D201][DEHP] exhibits unusual selectivity for scandium and low competitive behavior with other metals, thus increasing its market potential. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2479–2489, 2016     

赤泥-钛白废酸浸出液中微量钪的检测

研究了在赤泥-钛白废酸浸出液中微量钪(Ⅲ)的测定,采用铬天青S作显色剂,考察了反应条件对检测结果的影响,确定了酸浸液中钪的最佳检测条件。实验结果表明,有色溶液的最大吸收波长为615nm,表观摩尔吸光系数为1.57×105L·mol-1·cm-1。钪(Ⅲ)的质量浓度在0~14 g/50mL范围内符合比耳定律,分光光度法应用于赤泥-钛白废酸浸出液中微量钪的测定,结果满意。     

钪配合物催化丙烯与月桂烯的共聚合

研究了两种钪配合物(C5Me4SiMe3)Sc(CH2C6H4NMe2-o)2(记作钪配合物1,Me为甲基)和(C5Me4SiMe3)Sc(CH2SiMe3)2(THF)(记作钪配合物2,THF为四氢呋喃)催化丙烯与月桂烯共聚合的性能.结果表明:在室温及丙烯压力为0.6?MPa时,通过调控月桂烯的用量,采用钪配合物1和...     

四川某黏土矿中钪和钛的焙烧浸出试验研究

以四川某地含钪、钛、稀土黏土矿为研究对象,进行钠盐焙烧-酸浸、直接酸浸、硫酸化焙烧-水浸、空白焙烧-酸浸探索试验。结果表明,直接酸浸、空白焙烧-酸浸对钪和钛的回收效果均不好。硫酸化焙烧-水浸对钛的回收效果很好,但钪的浸出率较低。钠盐焙烧-酸浸试验结果表明,适宜的焙烧条件为:碳酸钠用量80%,焙烧温度800℃,焙烧时间1h;适宜的浸出条件为:10v.%硫酸,液固比20:1,浸出温度60℃,搅拌浸出时间2h;钪的浸出率为89.98%,钛的浸出率为80.55%。液固比对钪和钛的浸出率有显著影响,增大液固比可以暂时解决硅酸造成的过滤困难的问题。