废弃块矿作铺底料强化红土矿烧结工艺及机制  

Sintering performance and mechanism of limonite laterite strengthened by using waste lump ore as hearth layer

作　　者：朱德庆[1] 薛钰霄 潘建[1] 田宏宇[1] 潘料庭 黄庆周 ZHU De-qing;XUE Yu-xiao;PAN Jian;TIAN Hong-yu;PAN Liao-ting;HUANG Qing-zhou(School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,Hunan,China;Guangxi Beibu Gulf New Material Co.,Ltd.,Beihai 536000,Guangxi,China)

机构地区：[1]中南大学资源加工与生物工程学院,湖南长沙410083 [2]广西北部湾新材料有限公司,广西北海536000

出　　处：《钢铁研究学报》2020年第7期591-600,共10页Journal of Iron and Steel Research

基　　金：广西创新驱动发展专项资金资助项目(桂科AA18242003)。

摘　　要：为减少因低品位废弃含镍矿堆积而产生的重金属污染和镍资源浪费,同时达到有效利用固废资源及改善褐铁矿型红土镍矿烧结性能的目的,在研究两者基本物化性能及矿物赋存状态的基础上,对比了褐铁矿型红土镍矿无铺底料烧结工艺、烧结矿铺底料烧结工艺及废弃块矿铺底料烧结工艺各项指标,并揭示了相关机制。结果表明:相对于无铺底料烧结工艺及烧结矿铺底料烧结工艺,采用废弃块矿作为铺底料能更为有效地改善褐铁矿型红土镍矿烧结性能,烧结矿转鼓强度分别提高10.16%、3.82%,利用系数分别增加13.40%、6.80%,固体燃耗分别降低9.64%、9.20%;同时,烧结矿冶金性能优异,RI和RDI+3.15mm分别高达78.24%及96.79%。固结机制研究发现:相对于其他2种工艺,废弃块矿铺底料烧结工艺中,烧结矿微观结构由大孔薄壁结构转化为大孔厚壁结构,且孔洞趋于规则的圆形;另外,SFCA面积分数由7.27%、8.78%增至12.21%,并沿孔洞边缘向内部发展,主要固相—铁尖晶石晶粒有所长大,彼此之间连结程度较好,能更为有效地被液相所润湿,烧结矿微观结构更为紧密,从而使得烧结矿强度进一步提高。而强度更高的块矿作为铺底料,料层透气性更为有效地提高,促进了无烟煤的充分燃烧,使得烧结矿固体燃耗大幅降低,利用系数明显改善。In order to reduce heavy metal pollution and nickel resources waste by the accumulation of low grade nickel-containing waste lump ore,and at the same time achieve the effective utilization of solid waste and improvement of sintering performance of limonitic laterite,based on the characterization of the used waste lump ore and limonitic laterite,sinter indiators of limonitic laterite with different sintering processes were studied and the corresponding mechanism was revealed.The results indicate that,compared with sintering processes without hearth layer or with product sinter as hearth layer,sintering process using waste lump ore as hearth layer possesses better sintering performance with tumble index increased by 10.16% and 3.82%,productivity increased by 13.40% and 6.80%,and solid fuel rate lowered by 9.64% and 9.20%,respectively.Meanwhile,excellent metallurgical properties are obtained,i.e.RI of 78.24% and RDI+3.15mm of 96.79%.The investigation of consolidation mechanism demonstrates that,in the sintering process with waste lump ore as hearth layer,sintered ore mainly possesses large size and round pores with thick wall rather than large irregular thin-wall pores and the area fraction of SFCA is increased from 7.27% and 8.78% to 12.21% with extending along the edge of the pores to the internal structure of sintered ore.Besides,the main solid phase,i.e.hercynite,is more effectively wetted by the liquid phases including SFCA and eutectic spinel-type olivine phases with the grain aggregation and growth.All of them promotes the formation of close-knit sinter microstructure,leading to a higher sinter strength.Furthermore,waste lump ore with higher strength as hearth layer plays a better role on improving the permeability of sinter bed compared with product sinter of limonitic laterite which is beneficial to fully burning of anthracite,contributing to the substantial improvement of solid fuel rate and productivity of product sinter.

关 键 词：低品位废弃含镍块矿 铺底料 褐铁矿型红土镍矿烧结 透气性 固结机制 

分 类 号：TF046.4[冶金工程—冶金物理化学]