Study on Fluorine-Bearing Iron Concentrate Pellets Added With Dolomite

The effect of MgO on the properties of fluorine-bearing iron concentrate pellets was investigated.The results showed that the properties of green-ball did not change evidently with the increasing of the content of MgO.When the content of MgO was increased from 0.83% to 2.0%,the compression strength of roasted pellets was increased evidently from 3 555 to 5 050 N per pellet.However,CO2 from dolomite decomposition increased porosity of pellets,reducing the compression strength of preheated pellets.The compression strength of roasted pellets and preheated pellets were improved by prolonging the preheating time.Most of the MgO existed in iron phase which made magnetic iron ore and magnesia crystal lattice stable at high roasting temperature,these minerals were interconnected,tightened by cementation and mutual eroded with calcium ferrite and Fe2O3,all of them could improve the compression strength of roasted pellets.