摘要
针对云南某地铝土矿低铝、高硅和高铁的特点,采用焙烧—碱浸预脱硅工艺,获得高铝硅比铝精矿。考察焙烧温度、焙烧时间、碱液Na_(2)O浓度、碱浸时间、液固比对预脱硅效果的影响。在焙烧温度1050℃,焙烧时间30 min,浸出剂Na_(2)O浓度80 g/L,碱浸时间90 min,液固比L/S=8 mL/g的最佳预脱硅条件下,可将低品位铝土矿的铝硅比由4.08提升至17.98,脱硅率高达77.31%,同时预脱硅精矿氧化铝相对溶出率可达94.56%,溶出效果理想。结合热重-示差扫描量热、X射线衍射分析、红外光谱等多种表征手段,分析了焙烧—碱浸预脱硅机理,该铝土矿铝硅比的提高得益于原矿中高岭土类硅酸盐矿物通过焙烧可转化为碱溶性的无定型SiO_(2),采用常压碱浸即可实现铝硅高效分离,获得高铝硅比的铝精矿。
In view of the characteristics of low aluminum,high silicon and high iron in a bauxite ore in Yunnan province,a high aluminum-silicon ratio aluminum concentrate was obtained by roasting-alkali leaching pre-desilication process.The effects of roasting temperature,roasting time,Na_(2)O concentration,alkali leaching time and liquid-solid ratio on pre-desilication were investigated.Under the optimal pre-desilication conditions including roasting temperature of 1050℃,roasting time of 30 minutes,concentration of leaching agent Na_(2)O of 80 g/L,leaching time of 90 minutes,and liquid-solid ratio of L/S=8 mL/g,the Al-Si ratio of low-grade bauxite can be increased from 4.08 to 17.98,and the desilication rate is up to 77.31%,the relative dissolution rate of alumina in pre-desilicated concentrate can reach 94.56%,and the dissolution effect is ideal.Combined with thermogravimetric differential scanning calorimetry,X-ray diffraction analysis,infrared spectroscopy and other characterization methods,the mechanism of pre-desilication by roasting-alkali leaching was analyzed.The results show that improvement of the Al-Si ratio of bauxite is due to the fact that the kaolin-type silicate minerals in the raw ore can be first converted into alkali-soluble amorphous SiO_(2)by roasting,and the efficient separation of aluminum-silicon can be achieved by atmospheric pressure alkaline leaching,and aluminum concentrate with high aluminum-silicon ratio can be obtained.
作者
张笑天
徐璐
李超
李昃霖
杨耀辉
徐莺
冀成庆
ZHANG Xiaotian;XU Lu;LI Chao;LI Zelin;YANG Yaohui;XU Ying;JI Chengqing(Institute of Multipurpose Utilization of Mineral Resources,Chinese Academy of Geological Sciences,Chengdu 610041,China;Technology Innovation Center for Comprehensive Utilization of Strategic Mineral Resources,Ministry of Natural Resources,Chengdu 610041,China)
出处
《有色金属（冶炼部分）》
CAS
北大核心
2025年第1期77-83,118,共8页
Nonferrous Metals（Extractive Metallurgy)
基金
中国地质调查局地质调查项目(DD20230039)
贵州省科技计划项目(黔科合支撑[2023]一般171)
中国地质科学院矿产综合利用研究所基金项目(Skl2302)。
关键词
铝土矿
焙烧
碱浸
预脱硅
bauxite
roasting
alkaline leaching
pre-desilication
