Room temp. reduction of metal oxides by mechanical alloying

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We examined the reduction of metal oxides at room temperature by mechanical alloying method. Through ball-milling the solid metal oxide powders with solid reductant, the non-equilibrium chemical reactions are induced by force. 4 systems were carried out ; (1) silver oxides (Ag_2O,Ag_2O_2), (2) cupper oxides (Cu_2O,CuO), (3)zinc oxide (ZnO) and (4) iron oxides (FeO,Fe_3O_4, Fe_2O_3). Carbon powders were used for reductant. (1) and (2) were successful, so there is good possibility of the industrialization. And It was predicted that the pretreatment of the metal oxides was important for the reactions.Reactor System : Spex 8000 mixer was used for the experiments. The reactor were produced by way of trial with zirconia (volume = 60cc).Exp.(1) (Silver) : Both of the primary and the secondary oxides were reduced to metallic silver for comparatively short period, 20 or 30 minutes. Those reactions were momentary.Exp.(2) (Copper) : Metallic copper powder were obtained after 100 or 200 hours in the both oxides. Those reactions were continuously inactive.Exp.(3) (Zinc) : The raw ZnO easily adsorps H_2O,therefore the pretreatment, roasting, is necessary. With excess carbon, the reaction advanced inactively.Exp.(4) (Iron) : The reduction from hematite (Fe_2O_3) to magnetite (Fe_3O_4) were achieved, however the following reactions were interrupted. It is suggested that the interruption caused from that the adhesion of the powders to the reactor relaxd the invested mechanical energy.