Method of preparing sea crystal from byproduct salt of refining iminodiacetic acid

The invention relates to a method for preparing seawater crystal with refined iminodiacetic acid by-product salt and the steps are as follows in order: washing the by-product salt, solving, fine filtering, filtering with various medium, micro-filtering, chelating, secondary fine filtering, recrystallizing, centrifugating and drying, then adding a proportion of MgSO4, MgCl2, CaCl2, KCl and NaS2O3 into the salt to prepare seawater crystal and the proportion is: NaCl 72.3-77.5%, MgSO4 7.5-12%, MgCl2 11.6-13.5%, CaCl2 1.65-1.94%, KCl 1.35-1.64% and NaS2O3 0.001-0.002%, with the total percentage of 100%. The invention uses a method for preparing seawater crystal with refined iminodiacetic acid by-product salt, which is characterized in using by-product NaCl, reducing raw materials cost and protecting the environment, which is a typical clean production process.