The molecular structures of CaO-FeOx-SiO2 slags and their inorganic polymer counterparts were determined using neutron and X-ray scattering with subsequent pair distribution function (PDF) analysis. The slags were synthesized with approximate molar compositions: 0.17CaO-0.83FeO-SiO2 and 0.33CaO-0.67FeO-SiO2 (referred to as low-Ca and high-Ca, respectively)(.) The PDF data on the slags reasserted the predominantly glassy nature of this iron-rich industrial byproduct. The dominant metal-metal correlation was Fe-Si (3.20-3.25 angstrom), with smaller contributions from Fe-Ca (3.45-3.50 angstrom) and Fe-Fe (2.95-3.00 angstrom). After inorganic polymer synthesis, a rise in the amount of Fe3+ was observed via the shift of the Fe-O bond length to shorter distances. This shortening of the Fe-O distance in the binder is also evidenced by the apparent rise of the Fe-Fe correlation at 2.95-3.00 angstrom, although this feature may also suggest a potential aggregation of FeOx clusters. In general, the atomic arrangements of the reaction product was shown to be very similar to the precursor structure and the dominance of the Fe-Si correlation suggests the participation of Fe in the silicate network. The binder was shown to be glassy, as no distinct atom-atom correlations were observed beyond 8 angstrom.