Nb_(2)O_(5)-Al_(2)O_(3)-MgO-Na_(2)O-CaO-SiO_(2)体系相平衡研究  

Study on Phase Equilibrium of Nb_(2)O_(5)-Al_(2)O_(3)-MgO-Na_(2)O-CaO-SiO_(2)System

作　　者：陈昌 任国兴[1] 韩文生 冉孟杰 陈雯[1] CHEN Chang;REN Guoxing;HAN Wensheng;RAN Mengjie;CHEN Wen(Changsha Research Institute of Mining and Metallurgy Co.,Ltd.,Changsha 410012,China)

机构地区：[1]长沙矿冶研究院有限责任公司,长沙410012

出　　处：《有色金属（冶炼部分）》2023年第10期55-63,共9页Nonferrous Metals（Extractive Metallurgy)

基　　金：国家自然科学基金重大研究计划重点支持项目(92062223)。

摘　　要：为揭示Nb_(2)O_(5)-Al_(2)O_(3)-MgO-Na_(2)O-CaO-SiO_(2)多元含铌炉渣体系中的铌矿物的定向结晶规律,采用高温相平衡—冷淬—SEM-EDS/XRD/EMPA试验方法,考察了温度、钙硅比(CaO/SiO_(2))、Nb_(2)O_(5)含量等因素对炉渣相平衡关系的影响,并构建了含铌矿物结晶析出的优势相图。结果表明:铌的结晶矿物主要有三种,分别为Ca_(2)Nb_(2)O_(7)、Ca_((14-x))Nb_((2+x))Si_(8)O_((35+1.5x))和3CaO·MgO·Nb_(2)O_(5);铌先富集于液相,相较于脉石组分,含铌固相为后析出相;CaO/SiO_(2)增加会使含铌固相优势区间发生从Ca_(2)Nb_(2)O_(7)相到Ca_((14-x))Nb_((2+x))Si_(8)O_((35+1.5x))相、再到3CaO·MgO·Nb_(2)O_(5)相的转变。Ca_(2)Nb_(2)O_(7)相的优势析晶区间为:温度1050~1200℃,C/S=0.8~1.2。Nb_(2)O_(5)在Ca_((14-x))Nb_((2+x))Si_(8)O_((35+1.5x))相中的嵌布质量浓度在18.5%~19.5%。In order to reveal directional crystallization rules of niobium minerals in Nb_(2)O_(5)-Al_(2)O_(3)-MgO-Na_(2)O-CaO-SiO_(2)multi-component slag system,the influence of calcium-silicon ratio(CaO SiO_(2)),Nb_(2)O_(5)content and temperature on phase balance of slag was investigated by the high temperature equilibrium,cold quenching,SEM-EDS XRD EMPA method.A dominant phase diagram for the crystallization of niobium-containing minerals was constructed.The results show that three niobium phases are found in the system,it is Ca_(2)Nb_(2)O_(7),Ca_((14-x))Nb_((2+x))Si_(8) O(35+1.5 x)and 3CaO·MgO·Nb_(2)O_(5)respectively;Niobium is enriched in the liquid phase first,and compared with the gangue components,the niobium-containing solid phase is the later precipitated phase;With the increase of CaO SiO_(2),the dominant interval of the niobium-containing solid phase changes from Ca_(2)Nb_(2)O_(7) phase to Ca_((14-x))Nb_((2+x))Si_(8) O(35+1.5 x)phase,and then to 4CaO·MgO·Nb_(2)O_(5)phase.The dominant crystallization range of Ca_(2)Nb_(2)O_(7) phase is temperature at 1050-1200℃and CaO SiO_(2)=0.8—1.2.The intercalation mass concentration of Nb_(2)O_(5)in the Ca_((14-x))Nb_((2+x))Si_(8) O(35+1.5 x)phase is between 18.5%and 19.5%.

关 键 词：铌资源 相平衡 矿相转化 Nb_(2)O_(5)-Al_(2)O_(3)-MgO-Na_(2)O-CaO-SiO_(2) 

分 类 号：TF841.6[冶金工程—有色金属冶金]