How to extract lithium from aluminum ore clay?

Lithium is the lightest solid metal in nature and is widely used in various important application fields such as lithium-ion batteries, glass, ceramics, metallurgy, lubricants, nuclear energy and organic chemistry due to its high electrochemical activity, specific heat capacity, redox potential and other excellent properties. performance. The demand for lithium resources has greatly increased, making the extraction of lithium resources of great significance. Global lithium resources are abundant but unevenly distributed. Currently, lithium resources are mainly distributed in countries such as China, Chile, Argentina, Bolivia and Australia.

In recent years, a new type of bauxite clay rock closely related to carbonate rock deposition has been discovered in southwest China. At present, the main methods for extracting lithium from ores include sulfuric acid method, sulfate mixed sintering method and chloride roasting method. Among them, the sulfuric acid method is widely used to extract lithium from ores due to its high lithium leaching selectivity. Gu et al. once used medium-low temperature activation roasting and sulfuric acid leaching, and the lithium leaching rate could reach up to 86.23%.

According to the characteristics of high Al-Si content of this bauxite clay, it is suitable to be treated with sulfuric acid method. The aluminum hydroxide precipitation method cleverly utilizes the aluminum in bauxite clay rock to improve the extraction rate of lithium. First, the ground and calcined bauxite clay is leached with sulfuric acid to obtain a leachate with high concentration of Al 3+. Then, NaOH solution is added to form amorphous aluminum hydroxide to adsorb Li+. The precipitation rate of Li+ reaches 97.2% under suitable precipitation conditions. Finally, the precipitate is calcined and leached with deionized water to extract the lithium. Li+ achieved a water leaching rate of 86.13%. According to X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) results, the prepared precipitate is mainly amorphous aluminum hydroxide and partially composed of gibbsite phase. Elution experiments show that amorphous aluminum hydroxide has good adsorption selectivity for Li+. In addition, Al2O3 can be recovered from the solid phase after water immersion, which can significantly reduce costs.

In bauxite clay rock with extremely high Al 3+ content, through sulfuric acid leaching, NaOH is added to the leachate without adding an external Al source to form amorphous aluminum hydroxide, which has good adsorption selectivity for lithium. During the leachate precipitation process, the precipitation rate of Li+ can reach 97.2%. After calcination and water leaching of the precipitate, the water leaching rate of Li+ reached 86.13%.