The adsorption of tungsten on ferric oxide, manganese dioxide, slate, carbonaceous slate,kaolinite and bentonite in the solutions of pH 4---9 at atmospheric temperatures and pressures has been examined. Experimental r...The adsorption of tungsten on ferric oxide, manganese dioxide, slate, carbonaceous slate,kaolinite and bentonite in the solutions of pH 4---9 at atmospheric temperatures and pressures has been examined. Experimental results show that acidic solution is in favour of the adsorption of tungsten on the adsorbents. The adsorptivities of these adsorbents for tungsten decrease with increasing pH values for the solutions. Of all the substances joining the expe-riment, Fe2O3 is possessed of the highest adsorptivity and clays of the lowest. Their adsorptivities reduce in the order of Fe2O3, MnO, carbonaceous slate, SiO2, slate and clay in neutral and acidic solutions and of Fe2O3, carbonaceous slate, MnO, slate, clay and SiO2 in alkaline solutions. The adsorption of tungsten on the adsorbents and its pH dependence can be explained by the presence of W(VI) complex cations. The increase of pH results in the reduction of their quantities in the solutions with concomitant diminution of adsorptivity.Experimental data indicate that W shows a strong tendency of concentration during supergene processes in tungsten geochemical provinces. Therefore, it is of particular significance in the formation of tungsten-bearing formations.展开更多
文摘The adsorption of tungsten on ferric oxide, manganese dioxide, slate, carbonaceous slate,kaolinite and bentonite in the solutions of pH 4---9 at atmospheric temperatures and pressures has been examined. Experimental results show that acidic solution is in favour of the adsorption of tungsten on the adsorbents. The adsorptivities of these adsorbents for tungsten decrease with increasing pH values for the solutions. Of all the substances joining the expe-riment, Fe2O3 is possessed of the highest adsorptivity and clays of the lowest. Their adsorptivities reduce in the order of Fe2O3, MnO, carbonaceous slate, SiO2, slate and clay in neutral and acidic solutions and of Fe2O3, carbonaceous slate, MnO, slate, clay and SiO2 in alkaline solutions. The adsorption of tungsten on the adsorbents and its pH dependence can be explained by the presence of W(VI) complex cations. The increase of pH results in the reduction of their quantities in the solutions with concomitant diminution of adsorptivity.Experimental data indicate that W shows a strong tendency of concentration during supergene processes in tungsten geochemical provinces. Therefore, it is of particular significance in the formation of tungsten-bearing formations.
