高钙铁尾矿对多孔陶瓷烧结温度和性能的影响

Effect of High Calcium Iron Tailings on Sintering Temperature and Properties of Porous Ceramics

为促进矿业固废铁尾矿的高值化利用,以高钙铁尾矿作为主要原料,高岭土为黏结剂,石英作为骨料,碳化硅为发泡剂,采用“注浆成型-直接发泡法”制备高孔隙率铁尾矿多孔陶瓷,并通过测试多孔陶瓷孔隙率、孔径分布、体积密度和抗压强度,研究铁尾矿用量对多孔陶瓷烧结温度及性能结构的影响。结果表明,高钙铁尾矿可作为助熔剂使用,在原料配比为40%铁尾矿,20%高岭土、40%石英,外加0.3%碳化硅,烧结温度在1160~1170℃的条件下所制备的多孔陶瓷各项性能最优,其体积密度密度为0.38~0.46 g/cm^(3),气孔率高达80.84%~83.5%,平均孔径为0.33~0.88 mm,抗压强度为1.95~3.28 MPa。微观分析表明,铁尾矿内的方解石高温下分解产生的CaO可以与原料中的SiO_(2)反应生成钙长石,并大幅度降低材料的烧结温度和液相黏度,同时铁尾矿中的方解石和Fe_(2)O_(3)可以促进气泡的增长,有利于进一步提高气孔率。

In order to promote the high-value utilization of mining solid waste iron tailings,high-calcium iron tailings were used as the main raw material,kaolin was used as the binder,quartz was used as the aggregate,and silicon carbide was used as the foaming agent,the high-porosity iron tailings porous ceramics were prepared by"grouting molding-direct foaming method".The effects of iron tailings on the sintering temperature and performance structure of porous ceramics were studied by testing the porosity,pore size distribution,bulk density and compressive strength of porous ceramics.The results show that high calcium iron tailings can be used as fluxing agent.When raw material ratios are iron 40%tailings,20%kaolin,40%quartz,0.3%silicon carbide and sintering temperature is 1160-1170℃,the porous ceremics have the best properties.The bulk density is 0.38-0.46 g/cm^(3),the porosity is as high as 80.84%-83.5%,the average pore size is 0.33-0.88 mm,and the compressive strength is 1.95-3.28 MPa.Microscopic analysis shows that CaO produced by the decomposition of calcite in iron tailings at high temperature can react with SiO2 in raw materials to form anorthite,greatly reduce the sintering temperature and liquid viscosity of the material.At the same time,calcite and Fe2O3 in iron tailings can promote the growth of bubbles,which is beneficial to further improve the porosity.