System and method for deashing oil residues in direct coal liquefaction

The invention relates to the field of direct coal liquefaction, in particular to a direct coal liquefaction oil residue deashing system and method.The method comprises the following steps that S1, in an extraction device, solvent oil is used for extracting direct coal liquefaction oil residues, and extract liquor is obtained; s2, separating the extraction liquid in a settling separator to obtain settling top liquid positioned on the upper layer; s3, mixing the settling top liquid with a circulating material from a filter in a circulating pump to form a mixed material; s4, conveying the mixed material to a filter through a circulating pump, and filtering to obtain a concentrated solution, a purified solution and a circulating material; a ceramic membrane tube is arranged in the filter to serve as a filter element, the filter element comprises three layers of tube walls with sequentially increased pore diameters, the filter precision is high, the lipophilicity is good, in addition, when a mixed material is subj