Method for extracting valuable metal from clay type lithium ore step by step

The invention provides a method for extracting valuable metals from clay type lithium ores step by step, and relates to the technical field of lithium extraction. The method comprises the following steps: mixing clay type lithium ore and ammonium sulfate, granulating, and carrying out first roasting to obtain a roasted product; the roasted product is subjected to reduction water leaching through sulfur dioxide, and leaching liquid and leaching residues are obtained through filtering; and carrying out low-temperature freezing crystallization on the leachate to obtain a crystallized product and crystallized liquid. According to the method, valuable metals in the clay type lithium ore are activated under the action of ammonium sulfate, the activated roasted product is subjected to reduction water leaching with sulfur dioxide, the valuable metals in the roasted product are dissolved out of an aqueous solution, the sulfur dioxide reduces dissolved-out ferric ions into ferrous ions, and the ferric ions in the roast