关键词: 正交设计, 镁橄榄石, 球形骨料, 制备工艺

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