Thermally-induced color transformation of hematite: insight into the prehistoric natural pigment preparation

Improving the Reactivity and Stability of Fe2O3/Al2O3 in Chemical Looping Process by Optimizing the Al2O3 Precursor

“…Moreover, there is a surprising view that almost no obvious change in the micromorphology for the Fe 2 O 3 supported by Al 2 O 3 from the AlOOH, activated Al 2 O 3 , and Al­(OH) 3 , and no obvious sintering occurred. By comparing the macromorphology and elementary mapping on the cross section of the fresh and the cycled OCs, as shown in the Figure S6, it can be found that the surface color changed from dark red to red after CLHG cycling tests, which results from the electronic structure transformation under different treatment temperatures, and there is no clear phase segregation occurred between the Fe 2 O 3 and Al 2 O 3 for most OCs except for the Fe 2 O 3 –AlOOH and Fe 2 O 3 -inert Al 2 O 3 , which originates from the Fe 2 O 3 phase agglomeration in the CLHG cycling process and Al 2 O 3 particle agglomeration in the OC preparation, respectively. However, for other OCs, the stable phase distribution may be a result of the low reduction degree for the OCs in the present work conditions and improved mass transfer ability for the prepared OCs when compared with the work by Kidambi et al…”

Arsenic, cadmium, lead, antimony bioaccessibility and relative bioavailability in legacy gold mining waste

“…While grey battery sands contained 2.90 – 58.7% mica (biotite + ephesite + muscovite), calcine sands contained hematite as the second major phase [25.9 – 44.8%]. The presence of hematite confirms that these purple-colored materials were produced via high temperature roasting [ 35 ].…”