Method for extracting lithium resource from low-grade clay type lithium ore

The invention discloses a method for extracting lithium resources from low-grade clay-type lithium ores, lithium is extracted from the clay-type lithium ores through grading table pre-separation and middling and tailing roasting-water leaching, the table pre-removal can reduce the roasting treatment capacity, produced concentrate with high aluminum grade is used as aluminum concentrate, and the lithium resources are extracted from the clay-type lithium ores. Comprehensive utilization of lithium and aluminum is realized, and the operation cost is reduced; and secondly, the added mixture of sodium sulfate and hydrogen peroxide has strong reaction activity under low-temperature roasting, an acid leaching agent does not need to be additionally added in the leaching stage, most of the lithium element can be extracted through water leaching, and the method has the advantages of being high in extraction rate, low in cost, good in water leaching environmental protection property and simple in process. According to th