Abstract: Based on the problems，such as long mineralization and processing cycle，high impurity content，and difficult control to product quality，in the production of carnallite from the dissolved brine of Mahai salt lake with solarization process，a high temperature evaporation method was introduced for preparing carnallite and stepped evaporation research was carried out.Results showed solid product containing 92.23%（mass fraction） NaCl could be prepared with solid-liquid separation when the relative density of brine was 1.367 8；carnallite with the grade of 64.6% could be prepared by solid-liquid separation and the mass ratio of KCl to NaCl reached 1.94 when the relative density of brine was 1.417 5.In the range of 60~85 ℃，the temperature had  no significant impact on the solid-liquid separation in the preparation of carnallite，but Mg²⁺ content had a great influence on the viscosity of the brine.Through researching on the stepped evaporation process，carnallite could be separated from sodium chloride effectively and the carnallite mineralization could also be shortened.

Key words: salt lake, dissolved brine, high temperature evaporation, carnallite