Six additives,i.e.,limestone,lime,magnesite,magnesia,dolomite and light-burned-dolomite,were added for investigating their influences on the pellet quality.For green balls,adding lime and light-burned-dolomite makes t...Six additives,i.e.,limestone,lime,magnesite,magnesia,dolomite and light-burned-dolomite,were added for investigating their influences on the pellet quality.For green balls,adding lime and light-burned-dolomite makes the wet drop strength decrease firstly,and then increase with further increase of additive dosage.Ca(OH)2 affects the bentonite properties at the beginning,but the binding property of Ca(OH)2 will be main when the dosage is higher.The other four additives decrease the drop strength for their disadvantageous physical properties.For preheated pellets,no mater what kind of additive is added,the compressive strength will be decreased because of unmineralized additives.For roasted pellets,calcium additives can form binding phase of calcium-ferrite,and suitable liquid phase will improve recrystallization of hematite,but excessive liquid will destroy the structure of pellets,so the compressive strength of pellet increases firstly and then drops.When adding magnesium additives,the strength will be decreased because of the oxidation of magnetite retarded by MgO.展开更多
基金Project(2008BAB32B06) supported by the Key Projects in the National Science and Technology Pillar Program during the 11th Five-year Plan PeriodProject(2009ybfz20) supported by the Program for Excellent Doctor’s Degree Paper in Central South University,ChinaProject(1343/74333001114) supported by the Postgraduate’s Paper Innovation Fund of Hunan Province,China
文摘Six additives,i.e.,limestone,lime,magnesite,magnesia,dolomite and light-burned-dolomite,were added for investigating their influences on the pellet quality.For green balls,adding lime and light-burned-dolomite makes the wet drop strength decrease firstly,and then increase with further increase of additive dosage.Ca(OH)2 affects the bentonite properties at the beginning,but the binding property of Ca(OH)2 will be main when the dosage is higher.The other four additives decrease the drop strength for their disadvantageous physical properties.For preheated pellets,no mater what kind of additive is added,the compressive strength will be decreased because of unmineralized additives.For roasted pellets,calcium additives can form binding phase of calcium-ferrite,and suitable liquid phase will improve recrystallization of hematite,but excessive liquid will destroy the structure of pellets,so the compressive strength of pellet increases firstly and then drops.When adding magnesium additives,the strength will be decreased because of the oxidation of magnetite retarded by MgO.
