【摘 要】
：
In this work,a novel approach of leaching valuable metals,such as niobium,yttrium and cerium,from a niobium-bearing ore of low grade by roasting KHSO4-H2SO4 sys
【机 构】
：
National Engineering Laboratory of Biohydrometallurgy,GRIMAT Engineering Institute Co.,Ltd,Beijing 1
论文部分内容阅读
In this work,a novel approach of leaching valuable metals,such as niobium,yttrium and cerium,from a niobium-bearing ore of low grade by roasting KHSO4-H2SO4 system was experimentally studied.Through the work,the effects of roasting temperature,roasting time,mass ratio of agents to ore and the types of leaching agents on the extraction of Nb,Y and Ce were investigated,and the roasting KHSO4-H2SO4-ore system was thought as an effective method to extract these valuable metals.It was found that the recovery of Nb,Y and Ce can,respectively,reach 90.20％,97.22％ and 98.41％ in condition of roasting temperature of 300℃,roasting time of 2 h,mass ratio of KHSO4-to-H2SO4 to ore of 0.5∶1∶1,particle size of-74 μm(～95％),leaching solution of oxalic acid(30 g·L-1),leaching temperature of 90℃ and leaching liquid-to-solid ratio of 5∶1.The leaching kinetics of the calcined Nb-bearing ore in oxalic acid solution was suc-cessfully modeled by chemical reaction model,and the apparent activity energy was obtained to be 14.16 kJ·mol-1.The results generated from this work will provide the fundamentals for extracting Nb,Y and Ce from a niobium-bearing ore of low grade and have potential applications value in future.
其他文献
Magnesium alloys exhibit significant potential for use in next-generation biodegradable materials.Implanted magnesium alloys are expected to exhibit good wear resistance.In this work,the effects of rare earth metal Sc on the wear resistance of biodegradab
Microstructure evolution and properties of a Cu-Cr-Ag alloy during the continuous manufacturing process were investigated in detail by scanning electron microscopy(SEM)and transmission electron microscopy(TEM)in the study.The Cu-Cr-Ag alloy rod with unifo
Al-Cu-Li alloy is a huge potential alloy for aerospace industry due to its low density and excellent comprehensive performances.In this study,the microstructures and mechanical properties of a novel cast Al-Cu-Li alloy during the heat treatment were inves
Solvent extraction based on ionic liquids is generally considered to be an environmentally benign and effective technology for gold(Ⅰ)recovery.The aim of this work is to study gold(Ⅰ)extraction from aurocyanide solution using fluorine-free ionic liquids[A
The interaction mechanism of B and Ti in liquid Gd metal was theoretically analyzed,and the occurrence state transformation and removal of Ti impurity were experimentally analyzed in this study.The research results indicated that the B additive reacted wi
为解决金属管道损伤检测问题,提出一种非接触式谐波检测方法和目标信号辨识算法。首先利用调频载波构建谐波激励信号,并采用高灵敏度隧道磁阻(TMR)矢量传感器阵列进行信号采集。然后采用变尺度自适应时域随机共振(SR)增强目标信号能量,并引入量子遗传算法(QGA)对系统多参数寻优。最后通过正交锁相(OPL)与阵列融合方法抑制激励背景场,从而识别损伤源信号。建立仿真模型和室内实验平台对算法进行验证,并分析比较典型因素的影响效果。结果表明,该方法能够有效检测管道损伤并提取目标信号。
先进结构是支撑航天运载器研制及航天任务实施的基础,而先进材料与工艺技术则是先进航天运载器结构研制的重要基石。本文在简要论述航天运载器结构特点及我国发展趋势的基础上,综述了我国航天运载器结构金属材料、复合材料和智能材料的应用与发展需求,最后从超大型结构制造、整体高精高性能制造、复合材料结构制造、增材制造和绿色制造五个方面综述了航天结构先进工艺技术的未来发展趋势,并对重点研究方向进行了展望。
为降低噪声干扰、低频误差及信号漂移等对加速度信号积分位移信号还原度的影响,提出了一种采用自适应噪声的完备集合经验模态分解(CEEMDAN)算法和小波阈值去噪对加速度信号进行预处理,时域积分结合频域积分的位移信号还原方法。通过仿真分析及试验测试结果对比,该方法能够有效降低采集的加速度信号中存在的高低频误差影响。误差评价指标MAE和RMSE均有改善,混合积分方法位移信号还原程度高。
光栅测量的分辨率受限于光栅盘的刻划间距,需通过电子细分等方法提高其测量精度。文中借助时空转换原理,通过载波调制将表征光栅位移的莫尔信号相位加载到时间信号中。证明了通过对时间信号的周期测量实现光栅莫尔信号的40倍细分的方法可行性,并基于现场可编程门阵列(FPGA)平台设计了光栅莫尔信号的40倍细分集成化的功能电路;分别使用仿真与实际电路测试验证了细分方法的有效性。基于时空转换的数字细分系统具有可靠性高、易于集成以及低成本可定制化等优点。
The excitation wavelength-dependent and-independent emissions are two crucial fluorescent properties of carbon dots(CDs).However,CDs reported till date exhibit only one of these properties,which limits their practical applications.Herein,dual-property car