This invention discloses a method for the comprehensive utilization of
calcium and
magnesium solution and CO2, comprising the following steps: S11: using high-
salt calcium and
magnesium wastewater and CO2
tail gas as raw materials, the high-
salt calcium and
magnesium wastewater contains CaCl2 and MgCl2, water-soluble amine is added to the high-
salt calcium and magnesium
wastewater and mixed, and CO2
tail gas is introduced to carry out a mineralization reaction, generating
calcium carbonate precipitate, water-soluble amine
hydrochloride and
magnesium bicarbonate; S12:
solid phase
calcium carbonate is obtained by
solid-liquid separation, oil-soluble amine is added to the separated
liquid phase, HCl in the water-soluble amine
hydrochloride is extracted, the water-soluble amine is regenerated, and oil-soluble amine
hydrochloride and magnesium
carbonate trihydrate precipitate are generated; S13: after phase separation, the aqueous phase is separated by
solid-liquid separation to obtain
liquid phase water-soluble amine and solid phase magnesium carbonate trihydrate, and the oil-soluble amine hydrochloride in the
oil phase is pyrolyzed to obtain regenerated oil-soluble amine and HCl gas. This invention utilizes a water / oil dual-phase amine-enhanced calcium-magnesium solution mineralization CO2 and an extraction-
pyrolysis synergistic regeneration cycle process to achieve harmless treatment and
resource utilization of both calcium-magnesium-containing high-salt wastewater and CO2
tail gas.