Abstract: a process of removing impurities from brine by using crystallizer was introduced.The traditional process is adding sodium carbonate and sodium hydroxide directly into brine for removing impurities，which is easy to produce calcium carbonate and magnesium hydroxide colloid precipitation.And the colloid precipitation is difficult to filter.The crystallization elimination process was used to reduce the reaction concentration of calcium and magnesium，and reduce the concentration of the impurity ions at the same time，so that the supersaturation of the impurity crystals was controlled.The factors affecting the crystal growth of impurities were verified.The separation effect of saltmud of eliminating impurities from brine by crystallization and traditional process was compared.Experimental results showed that the rate of filtration was 30 times faster than traditional saltmud filtration.

Key words: crystallization；magnesium hydroxide；eliminating impurities from brine；crystallizer