Research On Occurrence State And Forming Process Simulation Of Copper And Silver In Iron-manganese Oxides

Iron-manganese oxiaes is an important mineral resources with the mainly minerals of limonite and psilomelane.It is also associated with some valuable elements,such as gold,silver,copper,lead etc.And the associated elements have a complicate occurrence caused by the similar geochemical parameters of the associated elements and iron/manganese in iron-manganese oxides.However,very little study has been published on the occurrence(especially the dispersed form)of the associated elements in iron-manganese oxides.Apparently,it is easily to recover the associated elements in the form of minerals and hard to recover the dispersed form,which leads to a low recovery rate of associated elements.The composition and content of mineral is gained through chemical analysis and MLA detection,the occurrence of copper,silver in limonite are researched by the microscope,MLA,XRD,EPMA combined with adsorption test,electrodialysis experiment,the forming process of associated elements occurrence in iron-manganese is studied by the roasting test,adsorption test,electrodialysis experiment.The conclusions are as follows,Selecting the limonite of Beiya gold ore Dali Yunnan as the research object,it is found that the limonite has a high purity with less psilomelane and coronadite.The limonite contains 52.42%iron,3.08%manganese,0.33%copper,50.16g/t silver by elements content analyze.The occurrence states study of copper and silver shows less copper and silver exists in the forms of independent mineral and micro-fine particle inclusion in limonite.The independent mineral is major of acanthite,chlorargyrite,native silver,malachite and chalcocite with a non-uniform dissemination size.Most copper,silver occurred in forms of ionic adsorption and isomorphism in limonite and psilomelane.The adsorption forms of copper and silver ion in limonite and psilomelane is studied by adsorption experiment of synthetic ferric oxide and manganese oxide colloid.The results shows adsorption capacity of manganese oxide is stronger than ferric oxide under the same condition.The forms of adsorption about copper and silver are specific coordination adsorption and electrostatic adsorption in manganese oxide surface and electrostatic adsorption in iron oxide surface.The roasting and electrodialysis experiment is studied on the colloid of iron oxide and manganese oxide after the adsorption experiment.The results shows that the electrodialysis rate of copper,silver for crystal is smaller than colloid in the result of a part of copper,silver in the form of ionic adsorption transform into isomorphism.It is speculated that the copper,silver adsorbed on the surface of limonite and psilomelane transform into isomorphism in the process of crystallization of limonite and psilomelane.