含碳球团熔融渗碳机理

使用CaO-SiO_2-Al_2O_3合成渣与磁铁矿、石墨粉制备含碳球团,考察了球团中渣相成分、渣量以及碳含量对铁水渗碳量的影响,并探讨了含碳球团内铁的熔融渗碳行为和机理。结果表明,熔融渗碳分为熔融还原渗碳以及铁熔体聚合过程渗碳2个阶段,前一阶段熔渣中Fe2+含量与铁的渗碳量处于动态平衡过程,主要受熔渣化学成分的影响;后一阶段的渗碳过程决定铁的物理渗碳极限,主要与铁、碳颗粒的接触条件有关,且熔渣中Fe2+的还原极限与渣相碱度和SiO_2绝对含量有关,铁的熔融渗碳量(质量分数)可以达到4%左右,满足铁锍分离要求。

Molten carburizing mechanism of carbon bearing pellet

The synthetic slag composed of CaO ,SiO2 and Al2 O3 ,was mixed with magnetite as well as graphite powder to prepare carbon bearing pellets ,in which amount and composition of the synthetic slag as well as carbon content were changed to examine the variation of carburizing content in molten iron ,and the molten carburizing be-havior as well as mechanism in carbon bearing pellets were discussed .The molten carburizing process proceeds in-to two stages :smelting-reduction and molten iron drops polymerization .There is a dynamic balance between Fe2+content in molten slag and carburizing content of molten iron during the first stage ,w hich is influenced by chemi-cal composition of the molten slag .The second carburizing stage determines the physical carburization limit of i-ron ,which is related to the contact condition between iron and carbon particles in pellets .Moreover ,the reduction limit of Fe2+ in molten slag is influenced by basicity and SiO2 absolute content .The molten carburizing content of iron in the present work reached about 4% ,which meets the requirement of separation between iron and matte melt .