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The elements and phase composition of a laterite nickel ore were analyzed and studied by ICP and XRD. The effects of acid concentration, solid-liquid ratio, stirring speed, leaching time and leaching temperature on the leaching of Ni, Co, Fe and Mg in laterite nickel ore under atmospheric pressure were explored through single factor condition experiment and comprehensive experiment, and the leaching kinetics of nickel was solved. The results show that the laterite nickel ore is silicon magnesium type. Under the conditions of acid concentration of 5 mol/L, solid-liquid ratio (g/mL) of 1 : 12, stirring speed of 250 r/min, leaching time of 150 min and leaching temperature of 85 °C, the leaching rates of Ni, Co, Fe and Mg are the best, which are 98.75%, 91.66%, 81.45% and 94.21%, respectively. The leaching process of nickel conforms to the shrinking core model, the reaction activation energy is 38. 804 kJ/mol, and the reaction process is controlled by the mixture of chemical reaction and internal diffusion. [ABSTRACT FROM AUTHOR]

The first-principles calculations are performed to investigate the geometric stability and the hydrogen storage capacity of lithium-decorated oxidized porous graphene (PG). Due to strong interaction between Li and O atom, two stable Li decorated structures have relatively high Li binding energies of 3.84 and 3.04 eV, which could eliminate the clustering problem for Li atoms on PG surface. One doped Li atom could hold five H2 molecules and the binding energy of each H2 is above 0.2 eV. The interaction of H2 molecules with Li atom results from charge exchange between H2's σ orbital and Li's 2s orbital. In the final structure with two Li-O groups in one carbon pore, a hydrogen storage capacity of 9.43 wt. % could be achieved. By the combination of the advantage of Li decoration and oxidized porous graphene, Li-OPG possesses remarkable geometric stability and high hydrogen storage capacity. [ABSTRACT FROM AUTHOR]