Winter Natural Evaporation Experiment of Deep Brine with Sand-gravel Pores in Da Lang Tan

A test on deep sand gravel-type pore brine from the Dalangtan area showed four salt precipitation stages under natural evaporation, with potassium mainly precipitating as carnallite. The potassium recovery rate reached 89.62%, and the mixed salt, rich in K⁺, Na⁺, and Mg²⁺ chlorides, is ideal for potassium chloride production. Calcium remained unprecipitated at a mother liquor density of 1.423 g/cm³, providing valuable data for brine resource utilization.