Calcium oxide from crushed oyster shells and calcined dolomite are mixed with seawater to create a slurry of magnesium hydroxide (milk of magnesia). Magnesium hydroxide is mixed with hydrochloric acid to produce magnesium chloride and water. The water is then evaporated to produce bittern or nigari, primarily magnesium chloride crystals. The magnesium chloride crystals can be processed into pure magnesium by being melted along with sodium chloride (table salt) to produce molten magnesium and chlorine gas. The chlorine gas can be mixed with hydrogen gas to become recycled hydrochloric acid.