The closest comparison in microstructure is a wustite
rich slag from the Lapphyttan smelting site, which originates from the iron refining process (Buchwald 2008, 212).
The mill scale originating in the steel production process consists of mainly three types of iron oxides: wustite
FeO, magnetite [Fe.sub.3][O.sub.4], and hematite [Fe.sub.2][O.sub.3] .
Besides [Fe.sub.2][O.sub.3], a small amount of wustite
[Fe.sub.1-x]O was detected.
When this sample (7.8% cow dung) was reduction roasted at 1073 K, diffraction peaks for wustite
(FeO) appeared, while the diffraction peaks of [Fe.sub.2][O.sub.3] were no longer detected (Figure 7(b)).
Other phases were also identified with insufficient amounts ashematite (Fe2O3) and wustite
Iron in a black tattoo ink is associated with the use of magnetite and wustite
(iron oxides) as components of the ink.
Pratsinis, "Direct synthesis of maghemite, magnetite and wustite
nanoparticles by flame spray pyrolysis," Advanced Powder Technology, vol.
The more important ones are FeO (wustite
), [lambda]-[Fe.sub.2][O.sub.3] (maghemite), [alpha]-[Fe.sub.2][O.sub.3] (hematite), and [Fe.sub.3][O.sub.4] (magnetite) with rock-salt, vacancy rich inverse spinel, corundum, and inverse spinel structures, respectively; the two former ones being thermodynamically less favorable and [alpha]-[Fe.sub.2][O.sub.3] being the most oxidized one.
One mineral crucial to revealing these details is wustite
, or FeO.
Analysis of water-cooled slag (average sample) preparation identified wustite
(FeO), dicalcium and tricalcium silicates (2CaO.Si[O.sub.2], [C.sub.2]S i 3CaO.Si[O.sub.2], [C.sub.3]S), brownmillerite [([Ca.sub.2] (Al, Fe).sub.2][O.sub.5], [C.sub.4]AF) and mayenite (12CaO.7[Al.sub.2][O.sub.3], [C.sub.12][A.sub.7]), as showed in Fig.