关键词: 水热法, 立方形碳酸锰, 锰系, 锂吸附剂

Abstract:

The micro-morphology of the adsorbent has a significant effect on its dispersion and adsorption behavior in solution.The manganous lithium adsorbent with controllable morphology and uniform particle size was prepared by hydrothermal synthesis of cubic MnCO₃ as a self-template.Using potassium permanganate，sucrose，and tartaric acid as raw materials，the effects of reactant concentration，solution pH，hydrothermal temperature，and hydrothermal time on the morphology of cubic MnCO₃ and the crystal structure and adsorption capacity of the corresponding adsorbent were investigated.The results showed that the optimum conditions for preparing cubic MnCO₃ by the hydrothermal method were as follows：the optimal reactant concentration was 7.406 2 g/L（in KMnO₄），LiOH·H₂O solution was used as pH regulator to adjust the pH of the reaction solution to 3.00，the hydrothermal temperature was 120 ℃ and the hydrothermal time was 36 h.Under the optimal hydrothermal conditions，the maximum adsorption capacity of the corresponding C-HMO for Li⁺ was 50.62 mg/g，the adsorption capacity was stable above 38.50 mg/g and the desorption rate of Li⁺ was above 80% in 5 adsorption-desorption cycles.X-ray diffractometer（XRD），scanning electron microscope（SEM），and synchronous thermal analyzer（TGA-DSC） were used to characterize the MnCO₃ prepared under optimal hydrothermal conditions.The results showed that the hydrothermal product MnCO₃ had a regular cubic structure，the single particle edge length was about 8 μm，the dispersion between the particles was good，the particle size was uniform，the impurity was less，and it had good thermal stability，which was an ideal raw material for the formation of cubic manganese series lithium adsorbent.

Key words: hydrothermal method, cubic manganese carbonate, manganese series, lithium adsorbent