Syntheses, Adsorption And Oxidation Of Todorokite-Manganite With Different Mn AOS

Mn oxide minerals are known as important adsorbents,redox agents,catalysts and environmental information carriers in soils,and their resource and environmental properties have been attracting more and more researchers' concern. Therefore,it is of great significance to promote exploration and utilization of Mn oxide minerals.Yodorokite is one important mineral of them for its 3×3 tunnel structural which is propitious to let the metal ion insert and emerge,and this outstanding property makes it is largely applied not only as oxide-redox and adsorbent,but also as the material for ion-change and electrode of lithium batteries.Based on the todorokite successfully obtained at atmospheric pressure and high pressure,we used general techniques to analyze the similarities and differences of the products synthesized in these two diverse methods.Meanwhile,the characteristics of oxidation of Cr and adsorption of Pb by amendable products were observed under experimental condition,as well as its chargeable and dischargeable capability as electrode of lithium batteries had been understood.The results are as follows:1,To obtain a series of products with different Mn AOS,we controlled the proportion of Mn(Ⅱ) and Mn(Ⅳ) in the precursor-birnessite,and via improve the traditional method,we got buserites with steady frame and different Mn AOS.2,By the method of synthesized at atmospheric pressure and high pressure,we got the Mn oxides which were mainly composed with todorokite.It was testified that birnessite was still remain in the products by traditional method,while it disappeared through the improved way,but some manganite was observed.Testing results identified that the products presented big Mn AOS differences.3,The products of todorokite-manganite with different Mn AOS presented variable oxidation property that was the sample with higher AOS had greater rate of oxidation of Cr(Ⅲ).4,The adsorption to Pb by the todorokite-manganite samples revealed different capability.The higher Mn AOS sample has a greater sorbed capability but lower Mn(Ⅱ) release ability during the adsorption process,and the release amount of H~+ rose when AOS went up,but the release amount of Mg had no remarkable relationship with AOS.5,The samples with different AOS as lithium electrode also revealed different chargeable and dischargeable capability It was noticeable that the samples with AOS between 3.46 to 3.73 demonstrated high capability in the first discharge,while the mineral with AOS 3.83 displayed lesser capability in the first discharge,but its cycles were excellent,the capability still remained about 79%after 40 times of charge and discharge cycles.