Using Geopolymer Technology on Reutilization of BOF Slag
Basic Oxygen Furnace (BOF) Slag is the by-product of the iron making industry. It produced over 150 million tons
annually in Taiwan. This kind of slag has great engineering properties, such as, high hardness and density, high compressive
strength, low abrasion ratio, and can replace natural aggregate for building materials. However, BOF slag has the expansion
problem, due to it contains free lime and MgO. The purpose of this study was to stabilize the BOF slag's expansion behavior
by using geopolymer technology, hoping can prevent the expansion problem and reutilization successfully. The experimental
results showed that using geopolymer technology can successfully prevent the expansion problem. The main properties are
analyzed with regard to their use as building materials. Autoclave is used to study the volume stability of these specimens.
Finally, the compressive strength of geopolymer mortar with BOF slag can be reached over 21MPa after curing for 28 days.
After autoclave testing, the volume change rate can be controlled lower than 0.2%. In this study have success using these
results on ready-mixed concrete plant, and have the same experiment results as laboratory scale, the specimen's compressive
strength can be reached over 40MPa after curing for 28 days. These results gave encouragement that using geopolymer
technology on reutilized BOF slag has a great potential.
Keywords - BOF Slag, Geopolymer, Free Lime, Swell Behavior.