A High Sulfur Concentrate Of Western Henan Desulfurization Test And Mechanism Research

The sulfer present in iron concentrate from the west of Henan is mainly pyrrhotite.which is easy to be oxidized?inhibited by lime and hard to be activated subsequently.Due to it's individual crystal chemistry property,it is difficult to sulfer removal from the concentrate with high sulfer content.In this thesis,single mineral flotation test,simulation calculation based on Material Studio,FTIR,XPS and XRD analysis,zeta potential analysis of mineral surface,surface thermodynamic calculation,flotation solution chemistry calculation have been conducted.To study the flotation mechanism of pyrrhotite such as collecting?inhibition and activation mechanism based on iron concentrate from the west of Henan,theoretical basis in iron concentrate from the west of Henan desulfurization process have been laid the foundation.The band structure and density of states of pyrrhotite calculation results showed that,pyrrhotite is an indirect semiconductor,and Fermi level closer to the valence band.This conducted adsorption on anion agents more easily.Besides,close to the Fermi level state density is mainly contributed by Fe3d orbital,that's meaned Fe atoms in pyrrhotite hold strong activity and prone to defect mode or replaced by other metal atoms.The results of single mineral flotation tests showed that pyrrhotite has a good natural flotability in a certain slurry pH and electrical potential of pulp;and the results of different inhibition of pyrrhotite turned out that the floatability descend with the oxidation under the natural conditions of laboratory simulation.The activation of pyrrhotite in different inhibition mechanism is slightly different,lime inhibition sulfuric acid and oxalic acid has a good activation effect under the single oxidation.Salt activator have similar activation trend,only in a certain range have a good flotability.On the basis of single mineral flotation experiment,the desulfuration flotation of contained pyrrhotite iron concentrate of western of Henan were tested.Under the isoamyl xanthate 750g/t,fluorine sodium silicate 3000g/t and 2#oil 60g/t,used a ro-ughing,cleaning,scavenging desulfurization process flow,could obtained iron conce-ntrate with total Fe 61.55%,sulfur 0.28%,total Fe recovery 87.89%.The pyrrhotite surface features are investigated,conclusion as followed.butyl xanthate and pyrrhotite can occured chemical adsorption,the adsorption product is dixanthate.Pyrrhotite have an excellent natural flotability as long as control pulp potential in a suitable scope.However,the Eh of pyrrhotite is lower in the water system,which meaned pyrrhotite is easy to oxidated excessively.On the other hand,from the oxidation of pyrrhotite Fe2p and S2p extension map,oxidized pyrrhotite surface products are hydrophilic Fe(OH)O and FeO(OH),explained that excessive oxidized pyrrhotite caused the poor flotability.In the calcium lime system,the corresponding combination of hydrophilic state form are Ca(OH)2 and CaSO4.After adding activator oxalic acid,sulfuric acid and fluorine sodium respectively,Ca binding energy disappeared significantly.Oxalic acid and sodium fluosilicate as activator have similar activation mechanism,they can not only reduce the slurry pH,improve the surface of pyrrhotite oxidation potential,but also being complexing agent of iron,calcium and other metal ion,generate soluble metallic complex salt.Molecular dynamics calculation test showed that,Ca(OH)2,CaOH+ and pyrrhotite interaction energy over the interaction energy of water molecule and hydroxyl ions Slightly,which indicated that Ca(OH)2 and CaOH+ would compete with water on the surface of pyrrhotite.Oxygen and pyrrhotite interaction energy over the water molecular interaction energy,which indicated that pyrrhotite are oxidized easily in oxygen flotation system.