Source separation of vanadium over iron from roasted vanadium-bearing shale during acid leaching via ferric fluoride surface coating
Source separation of vanadium over iron from roasted vanadium-bearing shale during acid leaching via ferric fluoride surface coating
复制标题
氟化铁表面涂层酸浸过程中从焙烧含钒页岩中钒与铁的源分离
DOI：
10.1016/j.jclepro.2018.01.226
复制
发表时间：
2018-04-20
影响因子：
11.1
通讯作者：
Xue, Nannan
中科院分区：
文献类型：
--
作者：
Hu, Pengcheng;Zhang, Yimin;Xue, Nannan
含钒页岩酸浸液中的钒在浸出过程中常被大量杂质污染，特别是铁杂质。因此，随着钒氧化还原液流电池、特种合金钢和催化剂等领域对钒产品需求的不断增加，从源头上分离钒和铁杂质以生产高纯钒产品是非常必要的。本文采用FeF 3表面包覆的方法实现了焙烧含钒页岩酸浸过程中钒与铁的源分离。在硫酸浓度为20vol%、浸出温度为95 ℃、浸出时间为4 h、液固比为1.5mL/g的条件下，加入5wt%CaF2时，钒的浸出率为89.8%，铁的浸出率仅为5.2%;然而，在不添加CaF 2的情况下，20.9%的铁和仅66.2%的钒被浸出。CaF 2与H2SO 4反应生成的HF能有效地分解白云母，是钒浸出率提高的主要原因。Fe 2 O3和FeSO 4+与HF反应生成的FeF 3对赤铁矿表面的钝化作用抑制了铁的浸出行为。FeF 3包覆层可有效阻止H+和SO 42-对赤铁矿的侵蚀，实现了酸浸过程中钒与铁的源分离。(c)2018爱思唯尔有限公司版权所有。
The vanadium in acid leachates of vanadium-bearing (V-bearing) shale is usually contaminated by massive impurities during leaching, especially iron impurity. Therefore, the separation of vanadium from iron impurity at source for the production of high purity vanadium products is of great necessity because of increasing demand for vanadium products in the fields of vanadium redox flow battery, specialty steel alloy and catalyst. In this paper, the source separation of vanadium over iron from roasted vanadium-bearing shale during acid leaching was achieved via FeF3 surface coating. Under the conditions of a H2SO4 concentration of 20 vol%, a leaching temperature of 95 degrees C, a leaching time of 4 h and a liquid-solid ratio of 1.5 mL/g, 89.8% of the vanadium leaching efficiency was obtained with only 5.2% of the iron leached with a CaF2 addition of 5 wt%; however, 20.9% of the iron and only 66.2% of the vanadium were leached without CaF2 addition. The enhancement of vanadium leaching efficiency was mainly attributed to the muscovite disintegration in HF generated from the reaction between CaF2 and H2SO4. The suppression of iron leaching behavior was due to the surface passivation of hematite coated with FeF3 which was generated from the reactions of Fe2O3 and FeSO4+ with HF. The FeF3 coating can prevent the attack of H+ and SO42- on the hematite; therefore, the source separation of vanadium over iron during acid leaching was realized. (c) 2018 Elsevier Ltd. All rights reserved.