四川高含硫气田产出水提锂工艺技术探索

Exploration of Lithium Extraction Process Technology for Produced Water from Sichuan High Sour Gas Field

四川某气田具有高含硫、局部存在底水的特征,气田伴生水日产1000 m^(3)左右,均属于高矿化度型卤水。地层水经过气田低温蒸馏站处理,产生的母液中锂元素含量约为0.25 g/L,远高于单独开采锂的工业品位,具有一定的经济价值。本文针对气田低温蒸馏站母液,围绕电化学脱嵌提锂法,实验配套了产出水除硫、除杂等预处理工艺,研究开发了高含硫气田产出水电化学脱嵌法提锂工艺技术,形成了提锂、沉锂、碳酸锂制备一整套工艺技术路线。根据实验结果,本文的提锂方法具有极佳的选择性提锂效果,地层水锂浓度可降至0.05 g/L以下,锂的直收率均在80%以上。电解材料的吸附容量单周期可以将富锂液的锂浓度浓缩到5 g/L,杂质离子截留率均在98%以上。该方法所得富锂液Li^(+)浓度高、杂质含量低,后续处理方便、成本低,该工艺完全能够满足气田低温蒸馏站母液提锂的需求。本文所形成的提锂方法为该类气井锂资源经济开发作出了有益的尝试,对促进气田开发成本有效降低具有重要示范意义。

The gas reservoir in Sichuan has the characteristics of high sulfur content and local presence of bottom water.The daily production of associated water in the gas field is about 1000 m^(3),all of which belong to high salinity brine.The formation water is treated by the low-temperature distillation station,and the lithium element content in the mother liquor is about 0.25 g/L,which is much higher than the industrial grade of lithium extraction alone,and has certain economic value.This paper focuses on the mother liquor of the low-temperature distillation station,and revolves around the electrochemical deinterlacing and lithium extraction method.Experimental supporting pre-treatment processes such as sulfur removal and impurity removal of produced water have been carried out.The research of the high sulfur water chemical deinterlacing and lithium extraction process technology have formed a complete set of process technology routes for lithium extraction,lithium precipitation,and lithium carbonate preparation.According to the experimental results,the lithium extraction method proposed has excellent selective lithium extraction effect,with lithium concentration in formation water falling below 0.05 g/L and direct lithium recovery rates above 80%.The adsorption capacity of electrolytic materials can concentrate the lithium concentration of lithium rich solution to 5 g/L in a single cycle,with impurity ion retention rates above 98%.The lithium rich liquid obtained by this method has high Li^(+) concentration and low impurity content,which is convenient for subsequent treatment and low cost.This process can fully meet the demand for lithium extraction from the mother liquor of the low-temperature distillation station.The lithium extraction method formed in this paper has made a beneficial attempt for the economic development of lithium resources in such gas wells,and has important demonstration significance in promoting the effective reduction of gas field development costs.