摘要
以湖北某地含钒石煤为原料,研究了空白焙烧-加助浸剂酸浸提钒工艺,并考察了在浸出时间为4 h,液固比:1.5∶1.0的条件下,焙烧温度、焙烧时间、硫酸浓度、助浸剂用量、浸出温度对钒浸出的影响,列出了白云母在浸出过程中与酸发生的主要反应,计算了各反应不同温度下的ΔGθT,并绘制了ΔGθ-T的关系图。研究表明:焙烧温度700℃,焙烧时间1 h,硫酸浓度4 mol.L-1,含氟助浸剂用量为原矿质量的5%,浸出温度为98℃条件下,钒的浸出率可达86%以上。由XRD,FTIR及钒的价态分析可知:空白焙烧能改变云母的内部结构,促进钒的转价;对于不同焙烧温度条件下的焙烧熟样,在浸出过程中加入含氟助浸剂,钒的浸出率较硫酸直接浸出时提高15%以上;热力学研究表明,含氟助浸剂中的F-易于与Si4+及Al3+反应生成络合离子,使白云母发生的反应的ΔGθ明显小于直接与酸的反应的ΔGθ;添加含氟助浸剂的酸浸体系对白云母结构的破坏能力明显大于空白焙烧过程。
The process of blank roasting-sulphuric acid leaching of vanadium with leaching agent was studied by using the stone coal in Hubei province as raw materials. The influence of roasting temperature, roasting period, dosage of leaching agent and extractiontemperature on the leaching of vanadium was observed individually when the liquid-solid ratio remained at 1.5：1.0 and leaching time was 4 h. The main reactions between muscovite and acid during the leaching process were given. And the ΔGθT of each reaction undera specific temperature was calculated, the ΔGθ-T state graph was provided as well. It showed that the leaching rate of vanadium could exceed 86% under the conditions that roasting temperature remained at 700 ℃ for 1 h, the dosage of F-contained leaching agent was5% of the raw ore＇s amount, the sulfuric acid concentration was 4 mol·L^-1 , and the leaching temperature remained at 98 ℃ for 4 h. From XRD, FTIR, and the valence state analysis of vanadium, it could be concluded that blank roasting could change the internalstructure of mica, thus causing the valence change of vanadium; for residues roasted under different temperatures, the leaching rate of vanadium increases by more than 15% with the addition of F-contained leaching agent instead of pure acid; and the addition of F-contained leaching agent could lower the AGe of the reaction of muscovite during the extraction process due to the fact that F- in the leaching agent was prone to react with the Si4＋ and Al3 ＋ to form complex ions according to thermodynamic study, and the damage to thestructure of mica in this process was much more serious than that in the blank roasting process.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2013年第3期446-452,共7页
Chinese Journal of Rare Metals
基金
国家科技部"十二五"科技支撑计划重点项目(2011BAB05B01)
国家环保部公益性项目(201009013)资助
关键词
石煤
酸浸
含氟助浸剂
热力学
stone coal
acid leaching
F-containing leaching agent
thermodynamics
