Method for preparing chlorinated polyethylene by recycling diluted hydrochloric acid phase

The invention provides a method for preparing chlorinated polyethylene by circularly applying a diluted hydrochloric acid phase, and belongs to the technical field of preparation of chlorinated polyethylene. The method comprises the following steps: mixing a stabilizer, a dispersant, polyethylene and diluted hydrochloric acid to obtain a mixed solution; introducing liquid chlorine into the mixed solution in sections for chlorination reaction to obtain slurry; the slurry is sequentially subjected to filtering, first-time permeation, first-time centrifugation, second-time permeation, second-time centrifugation, third-time permeation and centrifugal drying, and chlorinated polyethylene is obtained. By adding the stabilizer and the dispersing agent in a certain proportion, polyethylene has a relatively strong dispersion effect in an acidic system in the range of 6-20% hydrochloric acid, and meanwhile, segmented chlorine introduction and chlorine introduction amount suitable for an acidic environment are controlle