Patent ID: 8808660

Claim:
A precipitation method of at least one metal ion, wherein magnesium and/or calcium minerals are calcined and hydrated to get magnesium hydroxide and/or calcium hydroxide, which are further carbonated to obtain magnesium bicarbonate and/or calcium bicarbonate aqueous solution as at least one precipitant, and the magnesium bicarbonate and/or calcium bicarbonate aqueous solution is mixed with at least one metal salt solution, and a pH value of mother liquor is controlled within a range of 4.5˜8 to precipitate the at least one metal ion, and then, at least one selected from the group consisting of metal carbonate, metal hydroxide, and metal basic carbonate is obtained, during which carbon dioxide produced from a metal ion precipitation reaction between magnesium bicarbonate and/or calcium bicarbonate and the at least one metal ion is collected and recycled to precipitate the magnesium bicarbonate and/or calcium bicarbonate solution.