Evolution rule of powders during preparation of tantalum powders by magnesiothermic reduction-acid leaching
CHENG Yuewei1,2, CHEN Yi4, WANG Ruifang2,3,4, XING Yichen4, HAN Zhenghao4, CHE Yusi2,3,4, HE Jilin2,3,4
1. National Engineering Research Center for Special Metal Materials of Tantalum and Niobium, Ningxia Orient Tantalum Industry Co., Ltd, Shizuishan 753000, China; 2. National Key Laboratory for Special Rare Metal Materials, Zhengzhou University, Zhengzhou 450001, China; 3. Zhongyuan Critical Metals Laboratory, Zhengzhou University, Zhengzhou 450001, China; 4. School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
Abstract：Currently, the tantalum powders prepared by sodium reduction of potassium fluorotantalate cannot meet the requirements of high-end capacitors for the morphology uniformity and oxygen content of tantalum powders. This paper prepared tantalum powders by magnesium reduction of tantalum oxide-acid leaching process. The phase composition, micro-morphology, element content, and particle size distribution of tantalum powders before and after the acid leaching were studied using X-ray diffractometer, scanning electron microscope, energy spectrometer, laser particle size analyzer, oxygen/nitrogen/hydrogen analyzer, and inductively coupled plasma emission spectrometer. The results indicate that the tantalum powder particles inherit the morphology of the raw material. When n(Mg)∶n(Ta2O5)=5∶1, a few of the tantalum powders absorb hydrogen forming Ta2H during acid leaching owing to the fine grain and high activity of the tantalum, the insufficient magnesium led to the formation of Mg4Ta2O9 resulting from the reaction of unreacted Ta2O5 and MgO at this moment, which is difficult to separate from tantalum powders; when n(Mg)∶n(Ta2O5)=7.5∶1, the tantalum oxides are completely reduced to tantalum; when n(Mg)∶n(Ta2O5)=10∶1, the oxygen content of tantalum powders decreases to 0.58%, and the morphology uniformity is obviously improved.
程越伟, 陈熠, 王瑞芳, 邢奕辰, 韩正豪, 车玉思, 何季麟. 镁热还原-酸洗制备钽粉工艺中粉体的演变规律[J]. 粉末冶金材料科学与工程, 2025, 30(1): 35-41.
CHENG Yuewei, CHEN Yi, WANG Ruifang, XING Yichen, HAN Zhenghao, CHE Yusi, HE Jilin. Evolution rule of powders during preparation of tantalum powders by magnesiothermic reduction-acid leaching. Materials Science and Engineering of Powder Metallurgy, 2025, 30(1): 35-41.
[1] 何季麟, 张宗国. 中国钽铌工业的现状与发展[J].中国金属通报, 2006, 14(48): 2-8. HE Jilin, ZHANG Zongguo.Current status and development of tantalum niobium industry in China[J].China Metal Bulletin, 2006, 14(48): 2-8. [2] 杨国启, 何季麟, 郑爱国, 等. 电容器级高比容钽粉制备工艺研究进展[J].湖南有色金属, 2014, 30(1): 48-52. YANG Guoqi, HE Jilin, ZHNEG Aiguo, et al.Research progress of capacitor grade high capacitance tantalum powder preparation new technology[J].Hunan Nonferrous Metals, 2014, 30(1): 48-52. [3] 程越伟, 郑爱国, 潘伦桃, 等. 电容器用钽粉的高比容化[J].宁夏工程技术, 2006, 5(1): 99-101. CHENG Yuewei, ZHENG Aiguo, PAN Luntao, et al.Trend of high capacitance tantalum powder[J].Ningxia Engineering Technology, 2006, 5(1): 99-101. [4] 梁雅丽, 王英红. 高比容钽粉在电容器中的应用[J].电子元件与材料, 2006, 25(5): 46-48. LIANG Yali, WANG Yinghong.Application of high CV tantalum powder in tantalum capacitors[J].Electronic Components & Materials, 2006, 25(5): 46-48. [5] 李福成. 钠还原高比容钽粉湿法提纯过程中酸洗新工艺[J].河南理工大学学报(自然科学版), 2022, 41(4): 176-180. LI Fucheng.Pickling technology in the wet purification process of sodium reduction high specific capacity tantalum powder[J].Journal of Henan Polytechnic University (Natural Science), 2022, 41(4): 176-180. [6] 李福成, 杨雨, 包富贵. 高比容钽粉湿法新工艺提纯过程中物化性能的研究[J].宁夏大学学报(自然科学版), 2022, 43(3): 1-5. LI Fucheng, YANG Yu, BAO Fugui.High specific capacity metal tantalum powder wet new technology purification and chemical properties research[J].Journal of Ningxia University (Natural Science Edition), 2022, 43(3): 1-5. [7] 包玺方, 谢永旭, 李仲香, 等. 气流粉碎机在高压高比容钽粉中的应用研究[J].有色金属(冶炼部分), 2017(3): 44-48. BAO Xifang, XIE Yongxu, LI Zhongxiang, et al.Study on application of air jet mill in high voltage high capacitance tantalum powder[J].Nonferrous Metals (Extractive Metallurgy), 2017(3): 44-48. [8] 刘银元. 高压电解电容器用钽粉的制备[D].长沙: 中南大学, 2011. LIU Yinyuan.Preparation of tantalum powder for high voltage electrolytic capacitors[D].Changsha: Central South University, 2011. [9] 胡小锋. 熔盐电脱氧法制备金属Ta及Nb-Ta合金[D].沈阳: 东北大学, 2006. HU Xiaofeng.Preparation of tantalum and Nb-Ta alloy by electro-deoxidation in a eutectic CaCl2-NaCl melt[D].Shenyang: Northeastern University, 2006. [10] ZHU H M, SADOWAY D R.Synthesis of nanoscale particles of Ta and Nb3Al by homogeneous reduction in liquid ammonia[J].Journal of Materials Research, 2001, 16: 2544-2549. [11] 何季麟, 潘伦桃, 郑爱国, 等. 氧化钽(铌)还原制取钽(铌)粉的新方法[J].矿业研究与开发, 2003, 8(S1): 15-17. HE Jilin, PAN Luntao, ZHENG Aiguo, et al.A new method for making tantalum/niobium powder by reducing Ta/Ta oxide[J].Mining Research and Development, 2003, 8(S1): 15-17. [12] CHAI L Y, ZHONG H Y.Influence of alkali halide additions on tantalum powder production[J].Transactions of Nonferrous Metals Society of China, 1996, 6(3): 36-39. [13] 宋金磊. 多级深度还原法制备钽粉的基础研究[D].沈阳: 东北大学, 2019. SONG Jinlei.Basic research on preparation of tantalum powder by multistage depth reduction process[D].Shenyang: Northeastern University, 2019. [14] 雒国清, 李慧, 陈学清, 等. 氟钽酸钾还原制备工艺对钽粉性能的影响[J].有色金属(冶炼部分), 2022(11): 85-88. LUO Guoqing, LI Hui, CHEN Xueqing, et al.Effeet of potassium fluotantalate reduction condition on properties of tantalum powder[J].Nonferrous Metals (Extractive Metallurgy), 2022(11): 85-88. [15] 王东新, 李军义, 孙本双, 等. 还原氧化钽制备钽粉工艺研究进展[J].中国材料进展, 2011, 30(10): 54-58. WANG Dongxin, LI Junyi, SUN Benshuang, et al.Research progress on tantalum powder production technology by reducing Ta2O5[J].Materials China, 2011, 30(10): 54-58. [16] 马海燕, 王浩亮, 程越伟, 等. 氟钽酸钾钠还原搅拌釜中的搅拌流场数值模拟[J].有色金属(冶炼部分), 2022(12): 92-100. MA Haiyan, WANG Haoliang, CHENG Yuewei, et al.Numerical simulation of stirring flow field in stirred tank for potassium fluotantalate sodium reduction[J].Nonferrous Metals (Extractive Metallurgy), 2022(12): 92-100. [17] YUAN B Y, OKABE T H.Production of fine tantalum powder by preform reduction process using Mg-Ag alloy reductant[J].Journal of Alloys and Compounds, 2007, 443(1/2): 71-80. [18] OKABE T H, SATO N, MITSUDA Y, et al.Production of tantalum powder by magnesiothermic reduction of feed preform[J].Materials Transactions, 2003, 44(12): 2646-2653. [19] LEE Y K, SIM J J, BYEON J S, et al.Production of high-purity tantalum metal powder for capacitors using self-propagating high-temperature synthesis[J].Archives of Metallurgy and Materials, 2021, 66(4): 935-939. [20] ORLOV V M, KRYZHANOV M V.Magnesium-thermic reduction of tantalum oxide by self-propagating high-temperature synthesis[J].Russian Metallurgy (Metally), 2010, 2010(5): 384-388. [21] ORLOV V M, KRYZHANOV M V.Magnesiothermic reduction of Mg4Ta2O9 in the combustion regime[J].Inorganic Materials, 2018, 54: 910-914.
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