Technology survey and development tendency investigation on tantalum-niobium hydrometallurgical extraction

介绍了钽铌湿法冶金技术的发展概况和现状。根据分解介质的不同,钽铌湿法治金技术可分为碱熔融法、酸法和氯化法,碱熔融法可分为钠碱熔融法和钾碱熔融法,酸法主要有氢氟酸法和硫酸法。分别介绍了以上各方法的工艺路线,并对其优缺点进行了分析。针对现行氢氟酸工艺存在严重氟污染和对低品位钽铌矿分解率低的问题,依据清洁冶金原理,提出了钽铌亚熔盐清洁冶金新工艺,从生产源头消除了氟污染,可实现钽铌资源的高效清洁利用,具有良好的应用前景。The developments and current situation of tantalum-niobium hydrometallurgical extraction are presented.According to different decompositive medium,the tantalum-niobium hydrometallurgical extraction process can be classified as alkali fusion decomposition process,which mainly involves the sodium alkali fusion decomposition process and potassium alkali fusion decomposition process,while the acid decomposition process involving the hydrofluoric acid process and sulfuric acid process,and chlorination process.The principle of these process mentioned above is introduced respectively,and its merits and demerits are analyzed.At present,most minerals containing niobium and tantalum are decomposed by the hydrofluoric acid process.However,such a treating approach brings serious fluorin pollution to human beings and environment,and it is hard to decompose the refractory niobium-tantalum ore.With an objective to eliminate the fluorin pollution at the source,a new process for leaching the low-grade niobium-tantalum ore with alkali metals sub-molten salt is proposed.In the new process,alkali metals sub-molten salt is used as reaction medium to substitute the highly concentrated and toxic hydrogen fluoride solution of the traditional hydrofluoric acid process.And the clean conversion of niobium-tantalum ore is expected to be achieved.国家自然科学基金资助项目(20306031

Study on the Leaching Mechanism of Refractory Niobium-tantalum Ore by Concentrated Potassium Hydroxide

实验研究了难分解铌钽矿在高浓度氢氧化钾溶液中浸出过程的机理。考察了搅拌转速、反应温度、碱矿比、初始氢氧化钾浓度和矿粒度对铌钽矿中铌的浸出速率的影响。结果表明铌的浸出速率与铌钽矿粒径的平方成反比,浸出过程受克-金-布产物层固膜扩散控制,即1+2(1-X)-3(1-X)2/3=kt,并由阿累尼乌斯方程得到铌的表观活化能为72.2kJ﹒mol-1。结合动力学实验结果和电子扫描电镜(SEM)及X-射线能谱(EDAX)分析,进一步证明了在浸出过程中铌钽矿的表面形成了固相产物层,其主要组成元素为铁、锰等,并指出六铌(钽)酸根离子([(Ta,Nb)6O19]8-)通过固相产物层的内扩散为浸出过程的控制步骤。研究结果为浸出过程的强化提供了依据。The leaching mechanism of niobium from a refractory niobium-tantalum ore by concentrated potassium hydroxide was studied. The effects of stirring speed, reaction temperature, mass ratio of alkali-to-ore, initial potassium hydroxide concentration and particle size on the leaching rate of niobium were reported. The results show that the leaching rate is direct proportional to the inverse square of particle diameter, and the experimental data of the leaching rate are fit to the Crank-Ginsting-Braunshtein’s diffusion-through-layer-reaction-control model,that is: 1+2(1-X)-3(1-X)2/3=kt. According to the Arrhenius expression, the apparent activation energy for the leaching of niobium is 72.2kJ?mol?1. Based upon the result of the kinetic experiment as well as the SEM and EDAX analysis results, it is proved that during the leaching process of niobium-tantalum ore by concentrated potassium hydroxide, a solid product layer is formed on the surface of the unreacted core and its main composition elements are iron and manganese, the diffusion of [(Nb,Ta)6O19]8? through that layer is presumed to be the rate-controlling step of the leaching proces. The results obtained in this paper provide important basis for the strengthening of the leaching process.国家“十五”863资助项目(2001AA647010);; 国家自然科学基金资助项目(20306031)

Technology Survey and Development Tendency Investigation on ITO Films

综述了铟锡氧化物(ITO)薄膜的生产技术概况及其发展趋势。介绍了ITO薄膜的主要制备技术的制备原理,包括磁控溅射法、溶胶-凝胶法、化学气相沉淀法、喷雾热分解法及真空蒸发法等5种制膜工艺,并对其优缺点进行了分析。指出ITO薄膜生产技术的发展趋势为:1)大力开发溶胶-凝胶工艺;2)进一步深入研究其合成机理与性能;3)拓宽应用领域;4)开发先进的薄膜制备工艺技术。The technology survey and development tendency of ITO films were reviewed.The preparation principles of the main production processes of ITO films were introduced,including DCMS,CVD,Sol-gel process,chemical vapor deposition,spray-pyrolysis and vacuum evaporation,and their merits and demerits were analyzed.Based on the analysis results,the development tendency of production technology of ITO thin film are investigated as follows:(1) Developing the sol-gel process strongly;(2) Further studying their synthesis mechanism and properties;(3) Exploiting their application area;(4) Developing advanced preparation technology of thin film.国家自然科学基金资助项目(20306031

基于FBG传感技术的复合材料加筋板低速冲击损伤监测

针对碳纤维增强树脂基复合材料低速冲击损伤的实时监测,本文设计将布拉格光纤光栅(FBG)传感器埋植在复合材料加筋板结构的三角填充区,在线监测复合材料T型加筋板冲击损伤过程。分别将FBG传感器埋植于复合材料层合板内部和复合材料T型加筋板的三角填充区,对比FBG传感器的埋入对复合材料层合板与复合材料T型加筋板对力学性能的影响,结果表明内埋FBG传感器的复合材料层合板试样的拉伸强度比未埋植传感器的层合板试样降低了约5%,但在FBG传感器的破坏应变范围内,FBG传感器可以准确、实时地监测复合材料的应变信号。将FBG传感器埋入复合材料T型加筋板的三角填充区,内埋FBG传感器的加筋板样件压缩破坏载荷与未埋植的样件基本一致。通过对比加筋板蒙皮上冲击位置、冲击能量对FBG传感器测得的冲击过程持续时间和最大应变值的影响,表明冲击过程持续时间随着冲击能量增加而延长,最大应变值随着冲击距离的增加呈下降趋势,而最大应变值随着冲击能量的增加呈上升趋势。利用FBG传感器测得的应变信号可初步实现对复合材料T型加筋板蒙皮冲击损伤位置及冲击能量的实时监测。国家重点研发计划(2016YFD0700603);;航空科学基金(2016ZF68011);;江苏省重点研发计划(BE2015007);;福建省科技创新平台建设计划(2014H2006

Research on facial spectrum and color characteristics of five-zang disease status

目的:观察疾病状态人群面色光谱色度情况,为疾病状态五脏病评价提供可供依据。方法:采用日产柯尼卡美能达CM-2600d分光测色仪,观测健康组(183例)、疾病组(370例)额部、眉间部、鼻部、下颏、左右颧部、左右眼胞8处明亮度l、红光度A、黄光度b、饱和度C值及波长段(400~700nM)下的面色反射率值等指标,并据中医理论对疾病状态进行五脏病位分析。结果:疾病组l值显著低于健康组,b、C值均显著高于健康组;疾病组各波长段下反射率显著低于健康状态组(P<0.05)。疾病组除左右眼胞外的6个位点间的l、A、b、C值有显著性差异(P<0.05),不同点位有其特异性的色度变化特征。疾病组五脏病各组光谱色度特征比较有显著差异(P<0.05),结果与中医面部脏腑五色理论在一定程度上相符合。结论:运用光谱色度测定方法,可以作为诊断疾病状态五脏病的重要指标。Objective: To observe disease status facial spectrum and color,providing good quantitative basis for disease assessment.Methods: We gathered the facial color information in health(183) and disease groups(370) including L,a,b,C values and reflection of different wavelengths in 400-700nm with CM-2600D spectral photometric color measuring instrument on 8 points including frontal part,glabellas nose,mandible two cheeks and eye cells and analysized disease status five-zang positioning according to the principle of TCM syndrome differentiation.Results: L value of Disease group was lower than health status group and b,C values were higher than health status group,reflection of different wavelengths of disease group were lower than health group(P<0.05).6 points in disease group between loci L,a,b,C values with varying degrees of significant differences(P<0.05).Different point had its own specificity facial complexion variation characteristics.Facial spectrum and color of each five-zang disease group had significant difference through comparion of facial complexion.To a certain extent the result was consistent with TCM facial organs Five-color theory.Conclusion: There existed diagnostic value in distinguishing five-zang disease status in some degree by spectral photometric color measuring technique.国家科技支撑计划(No.2012BAI37B06);国家高技术研究发展计划(863计划)资助项目(No.2008AA02Z407);国家自然科学基金资助项目(No.30873463;No.81173200);国家自然基金青年项目(No.81102558);上海市重点学科(第三期)建设项目(No.S30302;No.S30303)---

对流扩散方程三角形有限元解的一致估计

利用三角形线性元的积分恒等式,给出了二维非定常对流扩散方程的半离散有限元解和真解的一致最优误差估计,即误差与ε无关,而仅与右端f和初值u_0有关