NOVELTY - Process for recovery of magnesium from a solution containing soluble magnesium, involves: precipitating magnesium hydroxide from the solution; forming an oxide blend including magnesium oxide derived from the precipitated magnesium hydroxide together with calcium oxide; reducing the oxide blend to form a magnesium metal vapor; and condensing the vapor to recover magnesium metal.    USE - For recovery of magnesium from a solution containing soluble magnesium including recovery of magnesium from a waste stream of a desalination plant, in which sodium chloride removed from the waste stream, and carbon dioxide produced during processing are useful in a bioreactor housing microalgae for production of biomass oil that is useful for production of biofuel (claimed). Also useful for converting a proportion precipitated magnesium hydroxide in a carbon dioxide sequestration process into magnesium carbonate, which is useful in a number of industries including direct use in the chemical industry, use in fertilizer production, and use in agri-water industries.    ADVANTAGE - The method provides a process for the recovery of magnesium from a solution containing soluble magnesium, such as in a high throughput solution feed, which is used in conjunction with other peripheral processes; and provides synergistic economical benefits. The method includes a pretreatment process, where prior to the precipitation of magnesium, the solution is treated to remove sodium chloride, such as by electrodialysis, which is electolyzed to form sodium hydroxide, which is then used for the precipitation of the magnesium hydroxide. Also a proportion of the precipitated magnesium hydroxide is converted into magnesium carbonate in a carbon dioxide sequestration process; and also allows for utilization of carbon dioxide generated during the burning of coal as a feed material to facilitate recovery of magnesium carbonate from a high throughput stream containing soluble magnesium derived from a desalination plant, which mitigates issues relating to carbon dioxide emission into the atmosphere. Further, a peripheral process that provides a synergistic relationship with the method involves utilization of sodium chloride recovered from the process or entrained in a waste stream emitted from the process, and carbon dioxide, such that the sodium chloride, and the carbon dioxide produced during processing or otherwise, are reported to a bioreactor e.g. a photo-bioreactor (such as ponds) housing microalgae for production of biomass oil that is then processable to biofuel. Thus the method addresses a globally recognized environmental problem of waste derived from coal-fired power plants and desalination plants in extreme quantities.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for recovery of magnesium from a waste stream of a desalination plant, involving: (a1) treating the waste stream using electrodialysis to remove sodium chloride; (b1) converting the sodium chloride removed from the waste stream to sodium hydroxide; (c1) reacting the sodium hydroxide with soluble magnesium in the waste stream to precipitate magnesium hydroxide; (d1) forming an oxide blend including magnesium oxide derived from the precipitated magnesium hydroxide together with calcium oxide; (e1) reducing the oxide blend to form magnesium metal vapor; (f1) condensing the magnesium metal vapor to recover magnesium metal; and (g1) reporting at least a portion of the sodium chloride removed from the waste stream and carbon dioxide to a bioreactor housing microalgae for the production of biofuel.    DESCRIPTION OF DRAWING(S) - The figure shows a flowchart illustrating a processing route for the magnesium metal recovery.