摘要
针对现有钒渣生产氧化钒工艺熟料浸出选择性差、浸出液杂质浓度高的问题,提出钒渣空白焙烧-碳酸氢钠浸出提钒新工艺,重点研究了焙烧温度、焙烧时间、钒渣粒度、碳酸氢钠浓度、浸出温度、浸出时间、熟料粒度、液固比对钒浸出率的影响规律,采用矿物解离分析仪(MLA)、扫描电镜(SEM)、能谱仪(EDS)等表征方法,分析了钒渣焙烧、浸出过程的物相和形貌变化特征.结果表明:钒渣空白焙烧过程中,钒主要与钙、锰结合生成焦钒酸钙锰,呈环状分布在氧化铁、铁板钛矿边缘;在焙烧温度930℃、焙烧时间120 min、碳酸氢钠浓度160 g/L、浸出温度95℃、浸出时间120 min、液固比(mL∶g)2∶1等条件下浸出,钒浸出率为94.03%;浸出液中钒38.83 g/L、硅0.21 g/L、铁0.08 g/L、磷0.08 g/L、钙0.02 g/L,锰、镁、铝、铬均＜0.01 g/L,这表明浸出液中杂质浓度低,实现了熟料中钒的选择性浸出.碳酸化浸出液中的钙、锰、镁、铁、铝、磷、铬浓度低且理论上不富集,沉钒后的上层液可直接循环浸出熟料,省去废水处理工艺过程,避免水处理固废产生.
Abstract
In view of the problem of poor selectivity in clinker leaching and high impurity concentration in leaching solution with existing vanadium oxide extraction process from vanadium slag,a new process for vanadium extraction from vanadium slag by blank roasting and sodium bicarbonate leaching was proposed.The research mainly focused on the influences of roasting temperature,roasting time,particle size of vanadium slag,sodium bicarbonate concentration,leaching temperature,leaching time,particle size of clinker and liquid-solid ratios on leaching rate of vanadium.The phase and morphology changes of vanadium slag during the blank roasting and carbonation leaching process were analyzed with mineral liberation analyzer(MLA),scanning electron microscope(SEM)and energy disperse spectroscopy(EDS).The results show that during the blank roasting process of vanadium slag,vanadium mainly combines with calcium and manganese to form calcium-manganese pyrovanadate,which is distributed in a circular pattern at the edges of iron oxide and pseudobrookite.The leaching rate of vanadium is 94.03%when the roasting temperature is 930℃,roasting time is 120 min,concentration of NaHCO3 is 160 g/L,leaching temperature is 95℃,leaching time is 120 min and liquid-solid ratio(mL∶g)is 2∶1.The leaching solution contains V 38.83 g/L,Si 0.21 g/L,Fe 0.08 g/L,P 0.08 g/L,Ca 0.02 g/L,and Mn,Mg,Al,Cr＜0.01 g/L,which means low impurity concentration,realizing selective leaching of vanadium from clinker.The carbonation leaching solution has low concentrations of Ca,Mn,Mg,Fe,Al,P and Cr,and theoretically does not enrich,the wastewater after vanadium precipitation can be directly used for leaching clinker,eliminating wastewater treatment processes and avoiding the generation of solid waste in water treatment.
基金项目
国家重点研发计划资助项目(2022YFC3901004)
NETL
NSTL
万方数据