Abstract: Sodium carbonate monohydrate from crude trona is prepared by calcining the crude trona to crude sodium carbonate, dissolving the crude sodium carbonate in an aqueous solution, clarifying and filtering the resulting solution to remove insoluble material to form a carbonate process solution, subjecting the carbonate process solution to a first crystallization to form a first crop of sodium carbonate monohydrate crystals from said carbonate process solution, subjecting the mother liquor separated from the first crop of monohydrate crystals and having a higher concentration of soluble organics to a second crystallization, including a crystallization temperature higher than that employed to obtain the first crop of said monohydrate crystals, to effect formation of a second crop of sodium carbonate monohydrate crystals, and separating said second crop of monohydrate crystals from a mother liquor having an organics level higher than said carbonate process solution and said mother liquor separated from said first cry