PROCESS FOR PRODUCING HIGH GRADE HYDROMAGNESITE AND MAGNESIUM OXIDE

摘要

The present invention provides a process for producing high purity hydromagnesite from a source of magnesium chloride. The process involves preparation of a magnesium chloride brine of a specific concentration, which is ammoniated at a specific temperature range, followed by carbonation, while maintaining the reaction at a specific temperature range to form a hydromagnesite precipitate. The product can be calcined to generate high purity magnesium oxide compounds.

主权项

1. A method of preparing hydromagnesite from a source of magnesium chloride, comprising:
a) preparing a feedstock brine solution from said source of magnesium chloride, wherein said feedstock brine solution comprises magnesium chloride and calcium chloride; b) mixing a sulfate salt into said feedstock brine solution to convert said calcium chloride into a calcium sulfate precipitate; c) removing said calcium sulfate precipitate from said feedstock brine solution; d) ammoniating said feedstock brine solution produced in step c) at a temperature range of about 20° C. to about 60° C. to convert magnesium chloride at least partially into magnesium hydroxide and to form ammonium chloride; and e) carbonating said magnesium hydroxide while maintaining the reaction temperature at about 20° C. to about 120° C. to form a hydromagnesite precipitate.