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Table 3 Key to grain populations shown in the flow-chart in Fig. 5, showing brief descriptions of diagnostic (mineralogical) characteristics and preferred interpretation per population

From: A method for analysis of nuisance dust from integrated steel works: chemical and mineralogical characteristics of contributing sources

ID Population's key phases/characteristics Preferred interpretation Source/material ID
w  < 15% Fe/FeOx: Ca-silicate with Ca–Al-silicate or P-rich Ca(-Mg–Al)-silicate Weathered converter slag 1
x As above, with > 5% sulphate Weathered converter slag; additional covering of sulphate phases on surface 1
y  < 15% Fe/FeOx: Ca-silicate ± Ca-(hydr)oxide/-carbonate with sum of both > 40% Converter-slag particles rich in C2S, C3S and Ca-hydroxide/-carbonate 1
z As above, with > 5% sulphate As above, with additional covering of sulphate phases on surface 1
aa  < 15% Fe/FeOx: Ca(-Al)-ferrite with apparent Mg–Ca–Fe-oxide from Mg–Fe-oxide + Ca-ferrite mixed pixels Converter-slag particles rich in brownmillerite intergrown with Mg-wustite (and the latter’s finely intergrown oxidation products) 1
ab As above, with > 5% sulphate As above, with additional covering of sulphate phases on surface 1
ac  < 15% Fe/FeOx: Mg–Fe-oxide with apparent Mg–Ca-Fe-oxide from Mg–Fe-oxide + Ca-ferrite mixed pixels Converter-slag particles rich in Mg-wustite (and its finely intergrown oxidation products) 1
ad As above, with > 5% sulphate As above, with additional covering of sulphate phases on surface 1
an  > 20% total Ca-ferrite + Ca(-Fe)-silicate, < 2% FeOx, with apparent Ca-aluminate pixels (probable aluminous brownmillerite) Converter-slag particles rich in brownmillerite 1
v  < 15% Fe/FeOx: Ca–Mg–Al-silicate with Ca-silicate Possible converter slag, rapidly cooled 2
q Ca-silicate with > 15% Ca–Mg-silicate Rapidly cooled converter slag—possible slopping material or formed during discharge of slag into cooling pits 2
ao  > 20% total Ca-ferrite + Ca(-Fe)-silicate with > 2% FeOx Sintered iron-ore material, rich in Ca-ferrites (chiefly SFCA and SFCA-I) and/or C2S 3
aq  < 20% total Ca-ferrite + Ca(-Fe)-silicate, with low apparent Fe-silicate Probable sintered iron-ore material with 1–20% Ca-ferrites (chiefly SFCA and SFCA-I) and/or C2S 3
ai FeOx with apparent Fe-silicate (including with minor Na, K, Al below peak threshold), < 1% Ca-ferrite Probable pelletised iron-ore material with highly silicic secondary silicate formed from reaction of ore gangue and FeOx during firing 4
aj FeOx with Mg–Fe-oxide (probable Mg-ferrite), < 1% Ca-ferrite Probable pelletised iron-ore material with Mg-ferrite-rich spinel solid solution phase formed by reaction with Mg-flux during firing 4
ap  < 20% total Ca-ferrite + Ca(-Fe)-silicate, with high apparent Fe-silicate Probable pelletised iron-ore material with highly silicic secondary silicate and Ca-ferrites or Ca–Fe-silicate: limestone-fluxed pellets only 4
r Mg–silicate (probable olivine) with Ca-ferrite ± Mg–Ca-silicate Partially reacted Mg-olivine (forsterite) flux in sintered or pelletised iron-ore material 5
ah Apparent Ca–Fe-silicate (including mixed FeOx—Ca-silicate pixels) or Mg–silicate with < 5% FeOx and < 1% Ca-ferrite Rare sintered ore particles 5
al  > 80% FeOx, < 1% Ca-ferrite Most commonly iron-ore particles with little adhering/intergrown binding matrix from sintering or pelletising process; also potentially oxidised metal/scrap 5
ak FeOx rich, < 1% Ca-ferrite Most commonly iron-ore particles, potentially with intergrown/adhering gangue phases 5
am FeOx dominated, < 1% Ca-ferrite, Zn(-Fe)-oxide > 5% FeOx dominated particles with significant content of Zn-oxide or Zn-Fe-oxide phase: potentially ore (agglomeration) material or Zn-rich scrap 6
ar Possible Fe-metal bearing, < 1% Ca-ferrite, > 80% Fe + FeOx Likely Fe-metal bearing particles/metallic slivers 7
as Possible Fe-metal bearing, < 1% Ca-ferrite Likely Fe-metal bearing particles/metallic slivers 7
at Possible Fe-metal bearing with Ca-ferrite or Ca-silicate Likely Fe-metal bearing particles/metallic slivers 7
e Zn-oxide/Zn–Fe-oxide with FeOx/Fe Particles rich in Zn-oxide/Zn–Fe-oxide: possible Zn-rich scrap 8
f Zn-oxide/Zn–Fe-oxide Particles rich in Zn-oxide/Zn–Fe-oxide: possible Zn-rich scrap 8
o Mg-(hydr)oxide/-carbonate with Mg–Al-spinel Possible de-sulphurisation process material 9
af Ca-aluminate rich Ca-aluminate rich slags from steelmaking processes 10
ag Ca-aluminate with Ca–Al-silicate with sum of both > 60% Ca-aluminate rich slags from steelmaking processes 10
n Dolomite/burnt-dolomite bearing Particles containing (burnt-)dolomite flux or thermal decomposition products thereof: iron-ore agglomeration and steelmaking processes 11
p Mg-(hydr)oxide/-carbonate ± sulphate/sulphide Combination of (at one time) MgO + sulphate is characteristic of partially reacted dolomite flux in iron-ore agglomeration; potentially also refractory material 12
l  > 60% Mg-silicate: probable forsteritic olivine Most commonly Mg-olivine flux used in iron-ore sintering and pelletising 13
m  > variable threshold % Mg-silicate: probable forsteritic olivine (set here to 60%) Most commonly Mg-olivine flux used in iron-ore sintering and pelletising 13
k Mg-(hydr)oxide/-carbonate with Mg-silicate (probable olivine) Possible tundish gunning-mass material: diagnostic phase combination of Mg-(hydr)oxide + Mg-olivine 14
ae Al2O3 or Al bearing Commonly alumina-dominated particles, otherwise alumina-bearing; encountered in iron-ore sinter reference materials but origin unclear 15
s Ca–Al-silicate rich Coherent population of particles dominated by Ca–Al-silicate pixels; unclear origin, speculative relationship with weathered converter slag 16
t Ca-(hydr)oxide/-carbonate rich Particles rich in Ca-(hydr)oxide/-carbonate lacking C2S or other Ca-silicates, Ca-ferrites and FeOx: potentially lime(stone) flux, particles of converter slag fully covered in a carbonate layer, as well as natural carbonate material 17
u Ca-(hydr)oxide/-carbonate rich with Ca-ferrite or FeOx Probable limestone flux residue from iron-ore sintering or pelletising with traces of reaction with FeOx (ore) 17
j Silica with Ca-silicate ± Ca-(hydr)oxide/-carbonate Possible cement/building material 18
d Gypsum/anhydrite dominated Likely urban dust, building material 19
au Ti-oxide bearing Source unknown, possibly ore-related 20
av Ti(-Al)-silicate bearing Probable paint chips/splinters 21
g Silica dominated Most commonly natural sand (quartz) 22
h Feldspar dominated Most commonly natural sand/rock 22
i Silica–feldspar–clay–mica mixture (any) Most commonly natural sand/rock 22
c  > 50% chloride/NaCl Most commonly salt from sea-spray/maritime influence 23
a Carbon rich with qz–clay–fsp–mica Probable coal/coke material with silicate ash phases 24
b Carbon rich Undifferentiated carbon-rich material: may include graphite flakes, organic carbon-based materials and diverse sources 25
aw Unassigned grains, < 40% empty spectra Unassigned grains with relatively low carbon content 26
  1. Assignment of grain populations to source/material categories as defined in Table 2 is also shown