Research On Variation Of Lithium Concentration During The Seawater And Brine Concentration Process

Sea water and salt lake bittern contain abundant resources, such as lithium resources, need reasonable development and utilization. The paper mainly studied the variation of lithium concentration during the sea water and a sulfate-type salt lake brine concentration process, respectively.Firstly, this paper studied the salts crystallization law and the lithium-varition concentration during seawater concentration process. And then analyzed the chemical composition and determined the lithium concentration of the22brines samples of different phases of salt field and23brine-samples of seawater evaporation, respectively. The results showed that, the cures of salts concentration and evaporation rate during the salt land and seawater concentration process are similar. With the evaporation rate increasing, the calcium sulfate and sodium chloride concentrations increased at the beginning and decreased latter, and the concentrations of magnesium chloride, magnesium sulfate, and potassium chloride increased gradually. Calcium sulfate began to separation when the evaporation rate was73.52%, sodium chloride began to exhalation at88.61%. Under the experimental concentration range, no lithium salts precipitated, and the lithium concentration increases as the evaporation rate improved-without absorbed by other salts.Secondly, this paper also studied salts crystallization law and lithium concentration variation during one sulfate-type salt lake brine concentration process. Analyzed the chemical composition and determined the lithium concentration of the14brine-samples after experimental brine evaporation. The results showed that during the brine concentration process, the bittern evaporation and the chloride and sodium ion increased at the beginning and decreased latter. But later, the content of the two appeared deviation with the potassium mixed-salt precipitated. And at evaporation termination, sodium content close to zero in the mother liquor, and chlorine ion greatly increased, more than25%. The change of sulfate ion and potassium ion were similar. In the first stage, the contents of sulfate ion and potassium ion increased at the beginning then decreased gradually; but at the late stage of potassium mixed-salt precipitated, both of them decreased greatly. During salt lake brine concentration process, lithium without absorption by other salts, instead, the concentration increased as the salt brine evaporation rate improved.The paper mainly studied the variation of lithium concentration during the concentration process of the sea water and one sulfate-type salt lake brine, can provided basis data for extracting lithium from the seawater and salt brine in the future.