Selective Li Extraction Strategy from Clay-Type Lithium Ores with Low Reagent Consumption: Briquetting-Enhanced Potassium Sulfate Roasting

With the rapid development of the global new energy industry, the strategic importance of lithium is becoming increasingly prominent. Clay-type lithium ore has attracted growing attention as an emerging resource, and its development and utilization are vital for a sustainable supply of lithium. Herein, a combined process involving potassium sulfate (K2SO4) roasting and water leaching was proposed to extract lithium from the clay-type lithium ore. Parameter optimization experiments indicated that the optimal Li extraction reached 93% with a 50% K2SO4 dosage and was roasted at 850 °C for 1 h. Comparative analysis of the raw ore, roasted product, and leached residue confirmed that the lithium extraction mechanism primarily involves ion substitution between Li and K. Additionally, we innovatively introduced briquetting technology to enhance the K2SO4 roasting process, ultimately reducing the K2SO4 dosage from 50% to 30%. This was attributed to the fact that briquetting pretreatment increases the effective contact area between K2SO4 and lithium-bearing minerals, thereby enhancing the solid–solid reaction efficiency. This study confirms that briquetting-enhanced roasting is an effective method for reducing reagent consumption, providing valuable insight for the economic and efficient extraction of lithium from clay-type lithium ore.