Method for recycling sylvinite by using carnallite decomposition mother liquor

A method for recycling sylvinite by using carnallite decomposition mother liquor comprises the following steps that 1, the carnallite decomposition mother liquor is heated to 70-80 DEG C, and the preheated carnallite decomposition mother liquor is divided into carnallite decomposition mother liquor I and carnallite decomposition mother liquor II; 2, the carnallite decomposition mother liquor II continues to be heated to be boiled and evaporated, then cooling, crystallizing and filtering are carried out, the obtained solid phase is artificial carnallite, and the liquid phase is old brine; 3, anhydrous thermal decomposition is carried out to obtain high-temperature solid-liquid mixed ore pulp; 4, dehalogenation is carried out, wherein the high-temperature solid-liquid mixed ore pulp obtainedin step 3 is subjected to heat preservation and filtration, solid-liquid separation is realized, and solid sylvinite and high-temperature mother liquor are obtained. The method is simple in technological process, easy to ope