1. College of Materials Science and Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China
2. China Building Materials Industrial Construction Xi’an Engineering Co., Ltd., Xi’an 710065, China
Aiming at the problems of poor grindability and low activity of steel slag, the method of adding grinding aids and RO phase separation was adopted to reduce energy consumption and improve its activity. The steel slag was ground by adding six kinds of grinding aids, and the effects of grinding aids on the specific surface area, particle size distribution and RO phase liberation degree of steel slag powder were investigated. After grinding, the steel slag powder was separated by RO phase, and the effects of separation on RO phase content, activity and hydration microscopic properties of steel slag were discussed. The results showed that grinding aids and RO phase separation can significantly improve the cementitious activity of steel slag. The addition of grinding aid improved the uniformity of particle size distribution of steel slag powder, increased the particle content of 3~32 μm, increased the specific surface area and RO phase liberation degree of steel slag powder, and reduced the RO phase content of steel slag powder by separation. The grinding aid TD (mixed with triisopropanolamine and diethyleneglycol 1∶1) has the best grinding aid effect and the largest liberation effect on the RO phase. After separation, the content of RO phase in steel slag powder is reduced by 38.58%. When the steel slag powder content is 30%, the activity index of 7 and 28 d is increased by 27.32% and 21.48% respectively compared with the blank group.