Variable grinding separation process for magnetic and hematite

The invention discloses a variable grinding separation process for magnetic and hematite, and belongs to the technical field of iron mine beneficiation. According to the method, one-section closed circuit ore grinding overflow control grading operation is adopted, the fineness of overflow products subjected to the one-section ore grinding grading operation meets the grading condition requirement, one-section closed circuit ore grinding overflow control grading operation equipment is composed of a ball mill, a spiral classifier and a hydrocyclone, hydrocyclone control grading is conducted through ore grinding grading overflow, and the grading efficiency is improved. The number of mills is reduced, configuration is simplified, and the problems that a spiral classifier adopted in traditional control classification is large in classification area and low in classification precision are solved; the requirements of independent magnetite production, independent hematite production and maghemite mixed production are