Abstract:

In order to research the influence of various factors on the properties of forsterite lightweight spherical aggregates and optimize its production technique,forsterite lightweight speherical aggregates were prepared using magnesite fine powder (<0.045 mm),natural silica powder (<0.048 mm) and silica fume as the starting materials,and magnesium sulfate solution with 15 mass% concentration as the binder,pelletizing on a disc pelletizer and sintering at high temperatures.The silica fume addition (5%,10%,and 15%,by mass),the rotation speeds of jar mill (300,400,and 500 r·min^-1),the milling times (1,1.5,and 2 h) and the calcination temperature (1 400,1 420,and 1 450 ℃) were chosen as the research factors,three levels of each factor were chosen for orthogonal design to research the effect of every factor on properties of spherical aggregates.The results show that:the silica fume addition and the calcination temperature are major factors,while the rotation speed of jar mill and the milling time are secondary factors.By comprehensive consideration,when the silica fume addition,the rotation speed of jar mill,the milling time and the calcination temperature are 10%,300 r·min^-1,1 h and 1 420 ℃,respectively,the production technique is opitimal.The lightweight spherical aggregates produced have good properties,evenly distributed pores diameter,and increased micropores,which are expected to become excellent basic heat insulation raw materials.

Key words: orthogonal design, forsterite, spherical aggregate, production technique

摘要：

为了研究各因素对镁橄榄石轻质球形骨料性能的影响以优化其制备工艺,以菱镁矿细粉(<0.045 mm)、天然硅石粉(<0.048 mm)和二氧化硅微粉为起始物料,使用浓度15%(w)的硫酸镁溶液为结合剂,采用圆盘造粒机成型料球,经高温煅烧后制备了镁橄榄石轻质球形骨料。选取二氧化硅微粉加入量(5%、10%、15%,w)、罐磨机转速(300、400、500 r·min^-1)、研磨时间(1、1.5、2 h)和煅烧温度(1 400、1 420、1 450 ℃)为研究因素,每个因素各选取3个水平进行正交设计,分析了各因素对球形骨料性能的影响。结果表明:二氧化硅微粉加入量和煅烧温度为主要影响因素,而罐磨机转速和研磨时间为次要影响因素。综合考虑,最优工艺路线为二氧化硅微粉加入量、罐磨机转速、研磨时间和煅烧温度分别为10%(w)、300 r·min^-1、1 h和1 420 ℃。采用优化工艺生产的轻质球形骨料的性能优良,孔径分布均匀,微孔数量增加,有望作为优良的碱性隔热耐火原料。

关键词: 正交设计, 镁橄榄石, 球形骨料, 制备工艺