从高钙富硼老卤中提硼研究

Boron Extraction from High Concentration Calcium Boron-rich Old Brine

以青海某高钙富硼老卤为研究对象开展了提硼研究。结果表明,合适的萃取条件为:磺化煤油为稀释剂、异辛醇用量50%、萃取相比1.0、萃取混合时间15 min;合适的反萃条件为:反萃剂为pH=1的稀盐酸、反萃相比1.5、反萃混合时间15 min。以此条件在5级混合澄清槽中完成了连续逆流萃取—反萃运转试验,连续运转45 h,硼萃取率为95.49%,硼与钾、钠、钙、镁的分离效果较好;硼反萃率为99.59%,反萃液中硼含量达17.17 g/L。采用“溶剂萃取—反萃—高温蒸发—低温冷却结晶—重溶—冷却结晶—过滤洗涤—干燥”工艺高效分离提取硼,硼总回收率为92.33%,制备出的硼酸产品达国家标准(GB/T 538—2018)要求。

Experiments of extracting boron from high concentration calcium and boron-rich old brine in Qinghai were carried out.The results show that the suitable extraction conditions including using sulfonated kerosene as diluent,volume fraction of isooctyl alcohol of 50%,extraction phase ratio O/A=1.0,and extraction time of 15 minutes,and the suitable stripping conditions including using hydrochloric acid solution with pH value of 1 as stripping agent,stripping phase ratio O/A=1.5,and stripping time of 15 minutes.Under these conditions,the continuous countercurrent extraction and stripping of boron were performed with five-stage mixer-settler.The experiment runs continuously for 45 hours.The five-stage extraction percent of boron is 95.49%,and the better separation efficacy of boron and sodium,potassium,calcium,magnesium is got.The five-stage stripping percent of boron is 99.59% and the concentration of boron in stripping solution reaches 17.17 g/L.Boron can be separated and extracted effectively by the process including solvent extraction,stripping,evaporation in high temperature and cooling crystallization in low temperature,redissolution and cooling crystallization,washing and drying.The overall recovery of boron is of 92.33%.The prepared boric acid products meet the requirements of national quality standard(GB/T 538—2018).