China Nonferrous Metallurgy

China produces a large amount of electric furnace Ferronickel iron slag (FNS), which has certain alkaline hydration activity and can be used as an auxiliary cementitious material. Ground granulated furnace slag (GGBS) has excellent hydration cementitious activity and is one of the best performing auxiliary cementitious materials. In order to maximize the utilization of FNS, this paper prepared active composite micro powder (CMP) by adding FNS into GGBS, and investigated its activation performance and mechanical properties. The main conclusions are as follows. Increasing the specific surface area of FNS can improve the mechanical strength of FNS-cement mortar specimens, but it will reduce toughness. When the proportion of FNS in the CMP is less than 20%, the CMP can meet the activity requirements of grade S105 GGBS. When the proportion is between 20% and 40%, it can meet the S95 level. The addition of FNS can reduce the grindability, so before mixing into CMP, the FNS needs to be pre-ground to a certain fineness. The addition of FNS can lead to early strength loss of mortar, but the its hydration activity gradually becomes apparent with increasing curing age. When the specific surface area of the CMP is between 410 and 432m2/kg, the activity can reach the level II composite admixture standard; when the specific surface area increases to 519m2/kg, the activity can reach the level I standard. The price of FNS is lower than that of GGBS, and adding FNS can reduce the production cost of CMP, but the proportion of addition should not exceed 20%. At this time, the cost can be reduced by about 10%, and it has good technical and economic efficiency.