Freezing Experimental Studies On The Salt Precipitation Law Of Jiezechak Salt Lake Brines

The object of the experiment is the water collected in jiezechaka Salt Lake.Concentrate the water by natural evaporation to get different concentration of brine,and then freeze the 8 groups of brine under different temperature.The experimental results show that:different ions concentration changes with the decreasing of the freezing temperature.Ions are rich in low density of the brine with the decreasing of the freezing temperature except SO42-,but in high density of the brine SO42-、CO32-、B2O3 and Cl-will precipitate significantly.Mirabilite(NaSO4·10H2O) can be crystallized significantly from the brine after frozen at-8℃ with the density higher than 1.228g·cm-3,at about -12℃,natron(Na2CO3·10H2O) can not be precipitated within this brine,but the amount of natron increased with higher density of the brine.Within a set temperature and density range,brine density control the salt precipitation type and salt precipitation rate. When the brine density is lower than 1.180g/cm3, the precipitated solid phase mainly is ice,brine density higher than 1.180g/cm3,mirabilite will precipitate, When the density exceeds 1.228g/cm3, the precipitation of solid phase add natron; and with the brine density increasing,frozen solid precipitation rate will increase significantly. The results also show that the freezing process can not only get rid of the SKO42-and CO32- in the brine,but also increase the concentration of Li+、K+and other elements。The enrichment of Li+ and K+ increase significantly with the freezing temperatures decrease.The experiment results has important guiding significance for lithium-rich brine preparation,all the results has a certain reference value for the process control of brine concentrating in the carbonate-type salt lakeFreeze the brine at -12℃ with the density at 1.228g/cm3 to get rid of mirabilite and get the liquor,then prepare brine according to the liquid brine composition. Concentrate brine by solar envaporation and get brine samples with different mass evaporation rate.Freeze brine samples at -12℃ and separate the solid and liquid phase. Analysis the composition of the liquid phase,the results show that the higher the evaporation rate,the greater efficiency of the removal of natron.Freeze the concentrated brine to get rid of natron after the process of removing mirabilite,this method has even higher efficiency of the removal of natron than freezing brine directly to remove natron.