Abstract: The present disclosure provides a process for recovering from high salinity liquid a substance comprising a selected alkaline earth carbonate salt, the process comprises (i) adding to said high salinity liquid a reagent comprising a solution of an alkali metal carbonate in an amount sufficient to allow precipitation of said substance in said liquid, while continuously introducing into the liquid a gas whereby a high degree of precipitate is formed in the liquid; and (ii) isolating said precipitate from the liquid, wherein said precipitate comprising the alkaline earth carbonate comprising substance in an essentially purified form (at least 95% w/w degree of purity). Also provided are a unit and a system constructed and operative for performing the process, preferably continuously.