Characterisation and leaching behaviour of granulated iron silicate slag constituents

The Effect of Zn Content and Granulation Temperature on Zn Leaching in an Fe-Saturated (FeXZn(1−X))2SiO4 System

“…The mineralogy and microstructure of the samples were studied via powder X-ray diffraction (XRD) using a PANalytical Empyrean X-ray diffractometer and via scanning electron microscopy (SEM) on a Zeiss Gemini Merlin instrument equipped with an Oxford Instruments energy-dispersive spectroscopy (EDS) detector, respectively [14]. XRD was used to determine the crystalline phases, over a 2θ range of 10.0131-89.9891 • with a step size of 0.0260 • and to quantify the amorphous and crystalline matter in the samples by Rietveld refinement, over a 2θ range of 5.0089-151.3109 • with a step size of 0.0130 • .…”

“…To compare the leachability of the different slag samples, leaching tests, as shown in Table 1, were conducted according to the two-stage batch leaching test at different liquid to solid ratios (L/S2 and 8), as specified in EN12457-3, and pH titration, performed as in an earlier paper by the authors [14]. The EN12457-3 test followed the standard protocol, except for the use of 25 g of solid with a size fraction of 0.3-0.6 mm and 50 mL (L/S2) or 200 mL (L/S8) of water (Milli-Q, Millipore).…”

“…The correlation between the chemical composition of the copper smelter slag and leaching has been addressed in several studies [10][11][12][13]. The sulfide and metal(loid) granules contribute to the leaching of Cu, Ni, As, and Sb when present in a fayalite-type slag [14]. The leaching from inclusions such as copper sulfides and metals (matte and metalloids) can be minimized by decreasing the content of inclusions.…”

“…Piatak et al concluded that, of the various slag types, those from copper extraction (including smelter and converter slag) leach the highest concentration of Zn when using equivalent leaching methods [5]. In addition, the authors concluded in an earlier study that the slag mineralogy has an impact on the leaching of specific elements [14]. Alter (2005) discussed leaching differences depending on the copper-smelter-specific raw materials, slag chemistry, and metallurgical processing [10].…”

“…Further, Kero Andertun et al showed that the oxidic glass phase is responsible for Zn leaching in fayalite slag [14]. The Zn leaching behavior of the oxide phase in fayalite slag has not been addressed in the literature and is a subject for further investigation.…”