Origin Of Lithium-rich Brine In Yiliping Salt Lake,Qaidam Basin

Lithium resources are abundant in China,especially in the middle of Qaidam Basin Yiliping,West Taijinaier,East Taijinaier and Qarhan constitute Lithium-rich brines area However,the following problems seriously affected Lithium-rich brines mineralization research and lithium industrial development:Metallogenic conditions especially climatic conditions of lithium-rich brine,the role of deep brine in the process of mineralization,enrichment mechanism of lithium-rich brine.This research studies the formation of lithium-rich brine in Yiliping salt lake in Qaidam Basinre relying on the National Key Research and Development ProjectIn this research,we studied the sedimentary characteristics,the chronological frame,the paleoclimate during the salt-forming period,and the changes in the composition of the brine by Sedimentology,U-series unequilibrium dating method of halite,fluid inclusion temperature measurement,LA-ICP-MS technology test.We founded:(1)at 40 ka the upper halite layer began to deposit and at 100-120 ka the lower halite layer began to deposit in HC2105 hole;(2)getting 232 homogenization temperatures,of which the maximum value of the homogenization temperature is 30.1?,the minimum value is 8.8?,and the average value is 20.4? by fluid inclusion temperature measurement,and Quantified the climate change of Yiliping Salt Lake since 120ka;(3)getting 21 inclusion components data,of which the minimum lithium ion concentration is 13.5 mg/L,the maximum is 248.1 mg/L,and the average concentration is 134.21 mg/L and founded the closely relationship between the change of Li+and the deposition rhythmBy analyzing the climatic conditions,the structural evolution and material sources of the lithium-rich brine of the Yiliping Salt Lake,the Yiliping Salt Lake was relatively stable Under the closed tectonic conditions,the flood river flows into the Nalingele River and enters Yiliping through Xitai Jinaire Lake.during the Holocene and Late Pleistocene.During this process,the climate of Yiliping Salt Lake fluctuated frequently,brine temperature between 8.8-30.1?,which is is conducive to lithium enrichment.When the temperature was relatively high,mineralization materials accumulate and when the temperature was low,the salt lake brine evaporates and concentrates,the concentration of various ions in the brine gradually increases,and the evaporite minerals begin to precipitate,forming sand-containing salt and stone salt.During this process,the concentration of Li continues to increase,eventually forming a lithium-rich brine.