The invention relates to a method for extracting
lithium salts from
saline salt brine with a
low magnesium-
lithium ratio through a
calcium cycling solid-
phase conversion method. The method is to take the
saline salt brine with the
low magnesium-
lithium ratio as a
raw material and adopt the technological flows of brine concentration,
magnesium and
sulfur removal through
lime cream,
calcium separation through
lithium carbonate, lithium extraction through
sodium carbonate,
thermal decomposition of
calcium carbonate, hydration of quicklime into cream, and the like to extract
lithium carbonate products. The main technical points of the method comprises that: the method is based on a
solid-
phase conversion principle of anions (OH, CO3) and realizes
magnesium and calcium removal of the brine, purification of the lithium salts and closed cycle of calcium through
solid-
phase conversion of Ca(OH)2, Mg(OH)2, Li2CO3, Ca(OH)2, CaCO3, CaO, Ca(OH)2. The method comprehensively utilizes
magnesium resources and lithium resources of
saline lakes, has the characteristics of
high magnesium removal efficiency, good purification effect of the lithium salts, high
recovery rate of lithium and magnesium, low
energy consumption, low cost, closed cycle of the calcium, small project investment, and the like, and is particularly suitable for industrial production on a large scale. In addition, the whole process is simple, clean and environment-friendly.