工业硫酸钡中钠、钙、钡、磷和硫的杂质形式分析

Studies on the speciation of impurity elements: sodium,calcium,barium,phosphorus and sulfurin industrial barium sulfate

在超声波辅助下对生产中各段工序的Ba SO4样品分别进行水浸取和酸浸取处理,用电感耦合等离子体发射光谱法(ICP-AES)对上述两种浸取液中的Na,Ca,Ba,P和S等元素的浓度进行测定,比较这两种浸取液中相应元素浓度的差异,并将它们与BaSO_4试剂作同样处理后的结果进行比较,结合工业BaSO_4的具体生产工艺,能够确定样品中Na,Ca,Ba和P的存在形式。通过分别加Bi^(3+)和Ba^(2+)到样品水浸取滤液中,测定加入Bi^(3+)和Ba^(2+)前后滤液中S的浓度变化,能够确定S元素的存在形式。水浸取的最佳条件为:固液比0.5000 g:14.0 m L,超声振荡时间30 min,温度为55℃;酸浸取的最佳条件为:固液比0.5000 g:14.0 m L,0.3 mol/L HNO_3溶液,超声振荡时间25 min、温度为35℃。结果表明,附着于工业BaSO_4上的主要杂质中,Na元素是以水溶性钠盐形式存在;S元素是以水溶性硫酸盐和硫化物,以及微溶Ca SO4形式存在;P元素少部分是以水溶性磷酸盐形式存在,而大部分是以酸溶性Ba_3(PO_4)_2和Ca_3(PO_4)_2形式存在。

With the help of ultrasonic,this experiment leached different industrial barium sulfate samples by water and acid respectively. The concentrations of sodium,calcium,barium,phosphorus and sulfurin the above leached solution were determined by inductively coupled plasma emission spectrometry（ ICP-AES）. The element concentrations obtained in two types of leaching solutions were compared each other and thene contrast to the pure barium sulfate. At last,combined with the manufacturing technique of industrial barium sulfate,the species of sodium,calcium,barium and phosphorus can be confirmed. By adding Bi^3＋ and Ba^2＋ to water leaching solution,and comparing the change of sulfur concentration,the species of sulfur could be confirmed. In the experiment,the optimum condition of water leaching was： 0. 5000 g ： 14. 0 m L of the solid-liquid ratio,30 min of the ultrasonic oscillation time,and 55 C of the temperature. The optimum condition of acid leaching was： 0. 5000 g：14. 0 m L of the solid-liquid ratio,0. 3 mol / L nitric acid,25 min of the ultrasonic oscillation time,and 35 C of the temperature. The results showed that impurity elements attached to barium sulfate surface exist in multiple species,such as sodium in the species of water-soluble sodium salt; sulfur in the species of water-soluble sulfate and sulfide. Meanwhile,sulfur also exists in the species of calcium sulfate slightly and phosphorus exists in the species of water-soluble phosphate. But the most of phosphorus exists in the species of acid-soluble barium phosphate and calcium phosphate. However,barium phosphate will be dissolved by acid solution and the Ba^2＋ is poisonous.