过氧化氢分光光度法测定湿法提钒工艺中钒

为了提高湿法提钒工艺过程控制效率,采用以过氧钒离子(VO(O₂)⁺)显色特性为基础的过氧化氢分光光度法测定钒含量,实现了样品中钒含量的现场快速测定。首先通过在试样溶液中加入适量氢氧化钠溶液,调整溶液pH值至9～10,然后加入过氧化氢将低价态钒全部氧化至钒(V),再加入硫酸调整溶液至酸性,钒(V)与过氧化氢在室温下形成稳定的红棕色过氧钒离子(VO(O₂)⁺),于450 nm处测定吸光度。钒质量浓度在2.0~400 mg/L内与吸光度值符合比尔定律。采用实验方法测定3种湿法冶金提钒液体试样(包括钒浸取溶液、钒盐沉淀后溶液以及废水等)中钒,结果的相对标准偏差(RSD,n=10)分别为0.38%、3.5%和7.6%;与高锰酸钾氧化-硫酸亚铁铵滴定法结果相一致。

Determination of vanadium in vanadium hydrometallurgy by hydrogen peroxide spectrophotometry

In order to improve the control efficiency of vanadium hydrometallurgy process, a method for the determination of vanadium content by hydrogen peroxide spectrophotometry based on the coloring characteristics of peroxide-vanadium ion VO(O₂)⁺] was proposed, realizing the rapid determination of vanadium content in sample on site. Firstly, the pH of sample solution was adjusted to 9-10 by adding appropriate amount of sodium hydroxide solution. Hydrogen peroxide was added to fully oxidize the low-valence vanadium to vanadium (V). Then sulfuric acid was added to adjust the solution to be acid. Vanadium (V) could react with hydrogen peroxide at room temperature to form a stable red-brown peroxide-vanadium ion VO(O₂)⁺]. The absorbance was measured at 450 nm. The Bill's law was obeyed between the absorbance and mass concentration of vanadium in range of 2.0-400 mg/L. The contents of vanadium in three vanadium extraction liquid samples of hydrometallurgy (including vanadium leaching solution, solution after vanadium precipitation, and wastewater) were determined according to the experimental method. The relative standard deviation (RSD, n = 10) of determination results was 0.38%, 3.5% and 7.6%, respectively. The found results were consistent with those obtained by potassium permanganate oxidization-ammonium ferrous sulfate titration method.