Factors Governing The Formation Of Lithiophorite At Atmospheric Pressure

Lithiophorite is a manganese oxide with layered structure, and commonly found in soils. The factors governing the formation of lithiophorite during refluxing process at atmospheric pressure and hydrothermal treatment, such as type of birnessite as precursor, configuration of lithium-aluminum hydroxide complex ions, reaction temperature and time, and pH were investigated by element analyses(ICP), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM), in this paper. The results were showed as following:1. It was favorable to formation of lithiophorite that the ion in the interlayer of birnessite was easily exchanged with lithium-aluminum hydroxide complex ions. The stabilization of ion in the interlayer of birnessite increased with the increase of crystallization, and the formation of lithiophorite would more difficult.2. The difference of configuration and amount of lithium-aluminum hydroxide complex ions synthesized at different temperature affect the transformation from birnessite to lithiophorite, and the lithium-aluminum hydroxide complex ion synthesized at 60℃was most favorable to formation of lithiophorite.3. The conversion rate and crystallinity of lithiophorite increased with the reaction temperature increase, and high crystal lithiophorite could be obtained in short time when birnessite was treated at 100℃at atmospheric pressure.4. The conversion rate and crystallinity of lithiophorite increased with prolonging the refluxing time of birnessite.5. Lithiophorite could be obtained during from a weak alkali medium to a slightly acidic medium, but it was most easily prepared in a neutrality medium.6. The crystallization and amount of lithiophorite in products of reflux could be increased by aging treatment for different time at room temperature or at 40℃. The effects of aging treatment for 6 months on the formation of lithiophorite were similar between two aging temperature.7. Lithiophorite could be synthesized in shorter time than refluxing method, and the crystallization of products was also better than that of refluxing treatment, but more easily produced other manganese oxide minerals phase during formation of lithiophorite under hydrothermal condition.