Method and device for purifying 2,4-dichlorophenol

The invention provides a method for purifying 2,4-dichlorophenol. The method comprises the following steps of cooling crude 2,4-dichlorophenol to 10 to 20 DEG C, stopping crystallization to obtain crystals, discharging mother liquor, heating the crystals and sweating at the temperature of between 30 and 50 DEG C, and discharging sweat to obtain the purified 2,4-dichlorophenol. According to the method, rectification is simple and easy to operate, the defects of high energy consumption and high production cost, damage to the health of operators and environment pollution due to the use of organic solvents and the like are overcome by fractional crystallization, and the requirements of industrialized production are met. The purity of the purified 2,4-dichlorophenol is over 98 percent, and requirements for preparing other products by using the purified 2,4-dichlorophenol are met.