Al-Othman A O, Sweileh J A
Department of Chemistry, Al al-Bayt University, PO Box 130040, Almafraq, Jordan.
Talanta. 2000 Apr 28;51(5):993-9. doi: 10.1016/s0039-9140(99)00361-6.
A fast method for sample treatment of phosphate rock has been developed for the purpose of quantitative leaching (98-100%) of fluoride but less of the interfering cations such as iron and aluminum. Citric acid (0.5 M) was used to extract fluoride in 15-45 min. Leaching of iron and aluminum is minimal, and these ions are complexed with citric acid. The leaching method was optimized with respect to sample size, citric acid concentration, leaching time and temperature. The analysis was completed by the rapid determination of fluoride with ion-selective electrode. The proposed treatment method was applied to phosphate rock samples from Jordan and Morocco and yielded accurate results as compared to the standard steam distillation from strong acid solution followed by thorium nitrate titration.
为实现氟的定量浸出（98 - 100%），同时减少铁和铝等干扰阳离子的浸出，开发了一种快速的磷矿石样品处理方法。使用0.5M柠檬酸在15 - 45分钟内提取氟。铁和铝的浸出量极少，且这些离子与柠檬酸形成络合物。该浸出方法在样品量、柠檬酸浓度、浸出时间和温度方面进行了优化。通过离子选择性电极快速测定氟来完成分析。将所提出的处理方法应用于约旦和摩洛哥的磷矿石样品，与从强酸溶液中进行标准水蒸气蒸馏然后用硝酸钍滴定相比，获得了准确的结果。
