基于硫酸铵+硫酸混合助剂的石煤焙烧─酸浸提钒

摘要

为了了解含钒石煤焙烧过程助剂硫酸铵+浓硫酸对焙烧—酸浸提钒效果的影响,以四川广元某V2O5含量为0.82%的含钒石煤试样为研究对象(33.03%的钒赋存在有机质中,59.45%的钒赋存在硅酸盐矿物中),在混合助剂硫酸铵与浓硫酸的物质的量之比为1:1的情况下,考察了焙烧温度、混合助剂添加量、试样的粒度和浸出温度对钒提取率的影响.结果表明,在添加硫酸铵+浓硫酸助剂的情况下,250℃焙烧导致试样中的云母相消失,伴随着硫酸铁铵、硬石膏新相的生成;焙烧温度上升到400℃,硫酸铁铵的衍射峰强度达到最强;继续提高焙烧温度至500℃,硫酸铁铵的衍射峰强度减弱;在320℃的焙烧熟料中有新相硫酸铝铵生成,至350℃处于增强阶段,至400℃硫酸铝铵相又全部消失.细度为-120目的试样按SO2-4与Al2O3+Fe2O3的物质的量之比3.5添加硫酸铵+浓硫酸,350℃下的焙烧熟料在90℃下进行硫酸酸浸,钒浸出率可达95.67%.%In order to understand the influence of ammonium sulfate and concentrated sulfuric acid additives on extrac-tion of vanadium in the process of roasting-acid leaching of vanadium-containing stone coal,taking the vanadium-containing stone coal fromguangyuan,Sichuan as the research object(33.03% of vanadium occurs in organicmatter,and 59.45% of va-nadium occurs in silicateminerals),the influences of roasting temperature,the dosage ofmixed auxiliary additives,particle size of the sample and leaching temperature on the leaching rate of vanadium were investigated under themole ratio ofmixed auxil-iary ammonium sulfate and concentrated sulfuric acid 1 : 1.The results showed that under the conditions of the ammonium sul-fate + concentrated sulfuric acid as additives,mica phase disappeared at roasting temperature 250 ℃with new phases NH4Fe (SO4)2and CaSO4generated. With the roasting temperaturegradually raising to 500 ℃,the diffraction peak intensity of NH4Fe (SO4) is weakened.A new phase NH4Al(SO4)2among roasting clinker wasgenerated at 320℃,raised at 350℃ and totally disappeared at 400 ℃;For the samples with fineness of -120mesh,adding ammonium sulfate + concentrated sulfuric acid with themole ratio of SO2-4 and Al2O3+Fe2O33.5,the roasting clinker with temperature of 350 ℃ was treated by sulfuric acid leaching at 90 ℃,and then the leaching rate of vanadium reached 95.67%.