Influence of Na2 CO3 as Additive on Direct Reduction of Boron-bearing Magnetite Concentrate

摘要

Boron-bearing magnetite concentrate is typically characterized by low grade of iron and boron (wTFe=51%-54%,wB2 O3=6%-8%),as well as the close intergrowth of ascharite phase and magnetite phase.A promising technology was proposed to separate iron and boron by coupling the direct reduction of iron oxides and Na activation of boron minerals together.The influence of Na2 CO3 as additive on the direct reduction of boron-bearing magnetite was studied by chemical analysis,kinetic analysis,XRD analysis and SEM analysis.The results showed that the ad-dition of Na2 CO3 not only activated boron minerals,but also reduced the activation energy of the reaction and pro-moted the reduction of iron oxides.Besides,the addition of Na2 CO3 changed the composition and melting point of non-ferrous phase,and then promoted the growth and aggregation of iron grains,which was conducive to the subse-quent magnetic separation.Thus,the coupling of the two processes is advantageous.