Process for producing magnesium metal from magnesium chloride brines

Claim 1

In a process for producing magnesium metal by electrolysis of a magnesium chloride electrolyte prepared from naturally occurring brines wherein a naturally occurring brine is treated in a succession of evaporation and concentration steps to form a magnesium chloride concentrate which is dehydrated by spray drying and chlorinated to remove occluded magnesium oxide the improvement comprising: treating a brine consisting essentially of from 7.0 to 7.5% Mg, water and trace amounts of metal impurities including from 400 to 550 ppm boron with an extractant to remove a major portion of the boron from the brine, desulfating and concentrating the partially deboronated brine, incorporating a gelling agent in said partially deboronated brine and homogenizing the brine-gellant mix to convert the brine to a magnesium chloride containing gel, chlorinating said gel by spray drying said gel in the presence of gaseous HCl to form a dried product comprising discrete particles of partially deboronated magnesium chloride substantially free of MgO, MgOHCl, and H 2 O and having a bulk density in the range of from 20 to 48 pounds per cubic foot, thereafter introducing said dried product without melting and chlorinating the same into an electrolytic cell and melting said dried product directly in said cell in the presence of fluoride ions to form a magnesium chloride electrolyte.