# Grain Size Effect in Elution Test of Electric Arc Furnace Slag
## 4 Conclusions  
The structure, microstructure and leaching behavior of EAF slags from seven different steel makers located in Brescia have been studied and their relationship with the parameters of the slagging procedure are discussed. We showed that, when silica is added during the slagging procedure, slags have low porosity and smooth surfaces. The element concentrations in the leaching tests samples are not significantly related to the slagging parameters and their high variability is mostly due to the furnace feeding and sampling.  
The influence of the granularity on leaching has been checked by sieving four samples in nine granularity fractions. In general, the results showed a positive trend with surface area and the element content, with the exception of V and Zn in one sample. This result is likely due to the effect of the grinding on phases, which will cause a higher percentage of hard phases in large grains. Indeed, this difference on phase percentages will change the solubility equilibrium of the leachates. Studies are in progress to demonstrate the correlation between the element concentrations in the leaching tests and the phase composition of the slags.  
New leaching test requirements for EAF slags must consider the effects due to the grain size, particularly when grinding is necessary for their uses.  
The following are available online at [[http://www.mdpi.com/2076-3417/10/2/477/s1](http://www.mdpi.com/2076-3417/10/2/477/s1)]([http://www.mdpi.com/2076-3417/10/2/477/s1](http://www.mdpi.com/2076-3417/10/2/477/s1)), Figure S1: XRD patterns of samples A, B, C, D1, E1, F and G, with the corresponding phase identification, Figure S2: XRD patterns collected on Fractions of the lowest (blue) and highest (black) size fraction of sample B, Table S1: Granularity fraction sizes, Table S2: Intra-sample and inter-sample RSD% variability, Table S3: Leaching test results performed in different laboratories, Table S4: Comparison between leaching test results performed by ICP-AES and TXRF, Table S5: Leaching test results performed by TXRF on the different granularity fractions.  
Conceptualization, A.R., L.B. and L.E.D.; methodology, A.R., L.B., L.E.D.; software, A.R., G.C., M.G., and A.Z.; investigation, A.R., A.Z., G.C., M.G., A.C.; writing--original draft preparation, A.R.; writing--review and editing, L.B., A.C., M.V.B., E.B., G.C., M.G.; supervision, L.E.D.; project administration, L.E.D.; funding acquisition, L.E.D. All authors have read and agree to the published version of the manuscript.  
This research was funded by Regione Lombardia Cariplo Foundation 19037, 18-12-2018 on B.U.R.L. n\({}^{\circ}\)52, 27-12-2018, grant n\({}^{\circ}\) 2018-1733, project \"Development of novel slag based glass ceramic for plasma spray coating and 3D printing--3D SLAG\", CUP E83D18000240009.  
The authors acknowledge RAMET consortium (Environmental Research for Metallurgy) for providing the samples and Eng. [PERSON] for useful discussion.  
The authors declare no conflict of interest.  
Figure 3: Normalized elements concentration of Ca, Zn, Sr, V and Ba measured by TXRF, in leachates from samples B, C. Reproduced in Colors.