To achieve efficient resource recovery of steel slag

the effects of roller method and hot smoldering process on the basic properties of steel slag were studied by means of X-ray fluorescence spectrometry (XRF)

X-ray diffraction (XRD)

scanning electron microscopy (SEM)

particle size distribution

stability

and grindability. Research indicates that the main chemical composition and phase composition of roller steel slag (RSS) and hot smoldering steel slag (HSSS) have little difference. RSS contains a large amount of dicalcium silicate (C2S)

tricalcium silicate (C3S)

and dicalcium ferrite (C2F)

and metal iron particles can be observed clearly. Compared with HSSS

the CaO content of RSS is larger

while the f-CaO content is smaller. Autoclave stability test was carried out under 2.0 MPa saturated steam

and it was found that with in the same particle size range

the stability index of RSS was higher than that of HSSS

indicating that RSS has better stability. Cement test mill was used for grinding

and the curve of specific surface area with the increase of grinding time was obtained. Results show that during the same grinding time

the specific surface area of RSS was smaller than that of HSSS. When the grinding time exceeded 70 min

the grinding efficiency of RSS tended to be gentle

while the specific surface area of HSSS increased by 15.67% when the grinding time reached 110 min

which suggests that RSS has poor grindability. Sizing experiments and crush value test show that the particle size of RSS was mostly 3-5 mm

while that of HSSS was mainly 3-10 mm

and the particle size distribution was relatively uniform. The crushing values of RSS and HSSS coarse and fine aggregates both reached the technical index of type I coarse and fine aggregates

which can thus be directly used as coarse and fine aggregates.