Abstract: To expand the utilization of iron tailings as secondary resources,lightweight closed-cell ceramsites were prepared using the SiC foaming method with iron tailings,quartz,and potassium feldspar as raw materials.The effects of the firing temperature (1 120,1 130 and 1 140 ℃ for 3 h),the ceramsite particle size (≤2.5,5-2.5 and 10-5 mm),and the addition of foaming agent SiC (1.0%,1.5%,2.0%,2.5% and 3.0%,by mass) on the structure and properties of the ceramsites were studied by XRD,SEM,FactSage software,etc.The results show that:(1)as the firing temperature and SiC addition increase,the bulk density and bearing capacity of the ceramsites decrease,and the ceramsites exhibit three pore structures: fine pore,honeycomb,and hollow;(2)with the firing temperature of 1 130 ℃,additions of 80.5 mass% iron tailings,10 mass% potassium feldspar,7 mass% quartz and 2.5 mass% SiC,as well as the ceramsite particle size of 10-5 mm,lightweight ceramsites can be obtained with a bulk density of 0.69 g·cm^-3 and bearing capacity of 311.2 N.

Key words: iron tailings, lightweight ceramsites, bulk density, bearing capacity

摘要： 为了扩大铁尾矿作为二次资源的利用范围,以铁尾矿、石英、钾长石为原料,利用SiC发泡法制备了闭孔轻质陶粒。借助XRD、SEM以及FactSage软件等手段研究了烧成温度(1 120、1 130、1 140 ℃保温3 h)、陶粒粒径(≤2.5、5~2.5、10~5 mm)以及发泡剂SiC的加入量(质量分数分别为1.0%、1.5%、2.0%、2.5%、3.0%)对陶粒结构和性能的影响。结果表明:1)随着烧成温度和SiC发泡剂加入量的增加,陶粒的堆积密度和承载能力均呈下降趋势,陶粒内部具有细孔状、蜂窝状、中空状3种气孔结构;2)当烧成温度为1 130 ℃,铁尾矿、钾长石、石英和SiC加入量(w)分别为80.5%、10%、7%和2.5%,陶粒的粒径范围为10~5 mm时,可获得堆积密度为0.69 g·cm^-3、承载能力为311.2 N的轻质陶粒。

关键词: 铁尾矿, 轻质陶粒, 堆积密度, 承载能力