페로니켈슬래그(FNS) 미분말을 활용한 그라우트재 연구

Abstract

The main raw material of stainless steel is called ferronickel slag, an eco-friendly resource with more than 1 million tons of emissions per year and excellent physical and chemical properties. It is a natural resource substitute for concrete aggregate, foundry sand, abrasive, and contributes to resource and environmental conservation. In Japan, New Caledonia and other advanced countries, ferronickel slag (FNS) has already been used in a variety of ways. However, in Korea, it can be recycled as fine aggregate for concrete but its utilization rate is insufficient. As a result, only 10% of the total amount of the total fraction is abandoned and landfill. Recently, the environmental pollution of the FNS buried has been controversial. There is still a problem with the treatment of FNS. To combat the current issue of dwindling resources and rising costs in construction materials, the use of FNS micropowder which is derived from waste arising, is being used for construction as well as ground amelioration. In this study, cutoff effect is confirmed from the mechanical characteristic of mixed cement paste with FNS micropowder and analysis of Gel-time. Land reclamation, environmental assessment of ground water and gushout water, soil pollution are performed to estimate the possibility of using in the field as an FNS grout material, concerning landfill. In the consequence of uniaxial compression experiment, strength has declined about 85%∼92% contrasted with 100% of cement strength when it is mixed with 10% of FNS micropowder instead of using cement. The optimal replacement ratio of FNS micropowder is 10% since there is large range of diminution strength when the proportion goes over 10% . From the result of constant head permeability test, it has found that the specimen, mixed with 40% of FNS micropowder, shows cutoff effect over than 20 times comparing with the specimen that has not been mixed with FNS micropowder. So, it is more suitable grout material for the ground that needs cutoff than strength enhancement. Furthermore, as a consequence of estimation in the affection of FNS to surrounding environment, detected harmful metals are all in 1 district tolerance range of concern level. It confirms that the heavy-metal contamination from FNS gushout was insignificant.