氟化氢在不同酸介质溶液中的离解性能研究  

Study on Dissociation Behavior of Hydrogen Fluoride in Different Acid Solution

作　　者：周安林[1] 昝琼[1] 李建峰[1] 刘建伟[1] ZHOU Anlin ZAN Qiong LI Jianfeng LIU Jianwei(Western Superconducting Technologies Co. Ltd., Xi’an 710018, China National Engineering Laboratory for Superconducting Materials,Xi’an 710018, China)

机构地区：[1]西部超导材料科技股份有限公司超导材料制备国家工程实验室,陕西西安710018

出　　处：《化工技术与开发》2016年第11期19-23,共5页Technology & Development of Chemical Industry

摘　　要：超导材料用铌钛、钽等金属采用硝酸和氢氟酸的混合酸液进行清洗,清洗后的废酸中含有大量游离氟离子.本文研究氟化氢在不同酸介质溶液中的离解特性,使废酸溶液中的氟化氢分子完全离解为游离氟离子,并降低氟离子浓度至排放标准以下,对于含氟废酸处理具有重要意义.取4%和20%的氢氟酸溶液、30%-35%分析纯硝酸＋8%-12%分析纯氢氟酸清洗铌钛后的废液、30%-35%分析纯硝酸＋15%-20%分析纯氢氟酸清洗钽后的废液,分别不断加入分析纯氢氧化钠、氯化钙和氢氧化钙,并测试溶液中游离氟离子浓度.结果表明：①稀溶液有利于氟化氢分子的离解;②废液中加入氢氧化钠后发生中和反应的同时,氢离子浓度降低促进了氟化氢分子的离解;③废液中加入氢氧化钙后发生中和反应促进氟化氢分子离解的同时,钙离子与游离氟离子结合形成氟化钙沉淀的化学反应更占主导;④废液中不断加入氢氧化钙,控制溶液pH在 8.5-9的基础上,通过加入氯化钙从而进一步降低游离氟离子浓度,可以使游离氟离子浓度达到排放标准要求.Niobium and tantalum metal for superconducting materials was cleaned with the mixed acid of nitric acid and hydrofluoricacid. There were a large number of free fluoride ion in waste acid. The study of the dissociation characteristics of hydrogen fluoridein different acid media was of great significance. Concentration of free fluoride ion in different solutions was tested by adding reagentof calcium hydroxide and sodium hydroxide. The results showed： （1）dilute solution was beneficial to the dissociation of hydrogenfluoride. （2）Neutralization reactions were occurring and the dissociation of hydrogen fluoride was promoted by the addition ofsodium hydroxide. （3）The dissociation of hydrogen fluoride was promoted and the precipitation of calcium fluoride was generatedby adding calcium hydroxide. （4）Concentration of free fluoride ion could meet the discharge standard by adjusting the amount ofcalcium hydroxide and adding calcium chloride.

关 键 词：游离氟离子 离解 中和 沉淀 

分 类 号：O645[理学—物理化学]