锂吸附剂在油气田卤水中的性能评价

Performance evaluation of lithium-based adsorbents in oil and gas fields brine

目的油气田卤水含有石油类、悬浮物等杂质,对锂资源的吸附分离存在潜在影响,考查了气田水吸附提锂的可行性及市面主流吸附剂的吸附提锂适应性。方法研究对比了pH、温度对铝系、钛系和锰系3种粉体吸附剂吸附、解吸效果的影响规律;对优选的铝系吸附剂,研究了其吸附剂形态、进卤量、进卤流量对成型吸附剂吸附、解吸效果的影响规律,并评估其循环稳定性。结果在最优条件下,3种粉体吸附剂饱和吸附容量分别约为7.9 mg/g、12.5 mg/g、15.3 mg/g。铝系吸附剂解吸液中钠锂比、钾锂比等要优于钛系和锰系,并且钛系和锰系吸附剂溶损率分别是铝系的20倍和70倍,长期运行情况下使用寿命要远低于铝系吸附剂。采用陶瓷膜去除卤水中的悬浮物和石油类,铝系成型吸附剂在进卤量为20 BV(1 BV=50 mL)、进卤流量为12 BV/h、解吸水量为10 BV、解吸流量为10 BV/h的条件下,连续10次循环单柱实验铝系吸附剂吸附容量和尾卤锂浓度保持稳定,平均锂吸附率为79.2%。结论综合证实采用吸附法提取龙王庙气田卤水中的锂资源是可行。

Objective Oil and gas fields brine contains impurities such as petroleum and suspended solids,which have potential impacts on the adsorption and separation of lithium resources.This papper studies the feasibility of lithium adsorption extraction from gas field water and the adaptability of mainstream adsorbents in the market for lithium extraction.Methods The study compared the effects of pH and temperature on the adsorption and desorption efficiency of three types of powder adsorbents:aluminium-based,titanium-based,and manganese-based adsorbents.Aluminium-based adsorbent was selected,and the effects of adsorbent morphology,brine,and brine feed flow rate on adsorption and desorption efficiency were studied,and its cycling stability was evaluated.Results Under the optimal conditions,the saturated adsorption capacities of the three adsorbents are approximately 7.9 mg/g,12.5 mg/g and 15.3 mg/g,respectively.In this experiment,the ratio of sodium to lithium and potassium to lithium in the desorption solution of aluminum adsorbent is better than that of titanium-based and manganese-based adsorbents,and the dissolution loss rate of titanium and manganese adsorbents is 20 and 70 times that of aluminum-based adsorbent,respectively.The service life during long-term operation is significantly shorter than that of aluminum series adsorbents.The ceramic membrane was used to remove suspended solids and petroleum from brine before the lithium extraction.Under the conditions of 20 BV of brine feed,12 BV/h of brine feed flow rate,10 BV of desorption water volume,and 10 BV/h of desorption flow rate,the adsorption capacity of aluminum molding adsorbent,as well as the concentration of lithium in tail brine remain stable in ten consecutive cycles of single-column experiments,with an average lithium adsorption rate of 79.2%.Conclusion It is feasible to use the adsorption method to extract lithium resources from the brine of Longwangmiao gas field.