Research Of Tuning Composition Of Molten Blast Furnace Slag For Direct Fiber Forming

Slag wool is prepared by industrial waste slag or industrial waste slag which isadded some acid conditioning agents. This kind of inorganic fiber produced bycentrifugal or injection blowing method after waste slag is re-melted. This kind of fiberhas a series of advantages, like good chemical stability, high temperature resistant andsmall coefficient of thermal conductivity. This topic is from the chemical composition ofblast furnace (BF) slag and conditioning agents. This study focus on the influence ofcomposition’s changing on slag acidity coefficient, mineral composition and slagmicrostructure and provide theoretical basis for direct production of high quality slagwool.Testing on mineral composition, viscosity and microstructure of blast furnace slagwere made by taking advantage of X-ray diffract meter, mineral microscope examinationinstrument. The results show that: there is a turning point in the BF slag’s viscosity-temperature curve. Also when modified slag acidity coefficient is1.0, there is a transformpoint in slag viscosity-temperature curves. BF slag and modified slag shows shout slagcharacter. And there is a narrow temperature range when the slag fiber forming viscosityis1～3Pa·s. A large number of mineral has appeared after water cooling. Melilite is themain minerals appeared in the slag, and it has a small amount of igneous rock. Slagviscosity-temperature gradient curve landing more gentle and inflection pointdisappeared when modified slag acidity coefficient is1.2~1.8. The slag short slagproperties disappear too. Water cooling slag all form vitreous analyzed by XRD spectrum.Combined the microstructure of slag with slag acidity coefficient, analysis resultsshow that: when taking fly ash and tailings as conditioning agent, slag acidity coefficientis1.2～1.8and1.2～1.6respectively, vitreous content is greater than97%after watercooling, when adding tailing into slag, slag acidity coefficient is1.8and vitreous contentdeclined, vitreous content is95%～96%.In the final, comparing the effect of two kinds of modified agent of BF slag, theappropriate modified agent adding proportion is: fly ash is15.5%～15.5%, and slagacidity coefficient is1.2～1.8; The adding proportion of tailings is16.98%～34.18%andslag acidity coefficient is1.2～1.6. Modified slag is suitable for the requirements of thepreparation of mineral wool materials. And this kind of slag satisfies the requirement ofhigh temperature viscosity when slag transform into the fiber directly.