Table 1 Selected PARC groups, correspondence with phases detected by XRD and other common phases/mixtures/artefacts inferred from detailed SEM–EDS analysis

{Si, Ca}

¹ C2S

Beta-C2S (larnite)

C3S (hatrurite, or breakdown products thereof); other Ca-silicate phases; mixed pixels—{Ca} calcite/lime/portlandite + {Si} silica

{Si, P, Ca}

Alpha'-C2S

Extreme P-rich variant: weathering product after C2S

{Fe}

{Fe, Fe(Kβ)}

FeOx/FeO(OH)/Fe

Hematite

Siderite; Artefact, {Fe, Fe(Kβ}} pixels used as tracer for iron metallic on grain/population/sample scale

Magnetite (incl. Mg-ferrite rich)

Goethite

Iron metallic

{Ca}

Calcite/lime/portlandite

Calcite

Lime

Portlandite

{Ca, Fe}

Ca-ferrites

² SFCA

Note: SFCA⟶CWF occur near exclusively in sinter, brownmillerite C2(A,F) dominantly in converter slag; Mixed pixels—{Ca} calcite/lime/portlandite + {Fe} FeOx may occur in poorly reacted pellet/sinter material

SFCA-I

SFCA-II

CF2

alpha-CF2

C2W4F9

CWF

{Al, Ca, Fe}

Brownmillerite C2(A,F)

{Al, Ca}

Ca-aluminates

C3A

Artefact pixels—highly Al-rich brownmillerite C2(A,F) where Fe peak intensity does not exceed threshold for assignment as {Al, Ca, Fe}

C12A7

³ CMAS Q-phase

{Si, Ca, Fe}

Kirschsteinite, clinopyroxene, amphibole

Kirschsteinite

Mixed pixels—{Si, Ca} C2S + {Fe} FeOx or {Ca, Fe} Ca-ferrites intergrowth in sinter

{Mg, Si, Ca, Fe}

Clinopyroxene

Mixed pixels

{Mg, Si, Fe}

Amphibole

Mixed pixels

{Mg, Si, Ca}

Monticellite

Monticellite

Clinopyroxene

{Mg, Si}

Forsterite

Forsterite

Orthopyroxene

{Al, Si, Ca}

Gehlenite and Katoite

Katoite

Ca-feldspar (anorthite)

Gehlenite

{S, Ca}

Gypsum/anhydrite

Anhydrite

Gypsum

{± , S, ±}

–

–

Diverse sulphates and sulphides; mixed pixels—sulphates on particle surfaces

{Si}

Quartz

Quartz

Amorphous silica; SiC

{Al, Si}

Kaolinite

Kaolinite

Mullite, other alumino-silicates

{Mg, Al, Si}

Mica

Mica

{Al, Si, K}

Feldspar

Feldspar

{Mg, Fe}

Mg-wustite

Mg-wustite

Mg-ferrite rich spinel solid solution in pellets and sinter; finely intergrown oxidation products after Mg-wustite in converter slag, including spinel solid solution (magnetite)

{Mg, Mn, Fe}

{Mg, Ca}

Dolomite

Dolomite

Decarbonation products after dolomite

{Mg, Ca, Fe}

–

–

Mixed pixels—{Mg, Fe} Mg-wustite + {Ca, Fe} brownmillerite C2(A,F) in converter slag

{Si, Fe}

–

–

Mixed pixels—{Si} silica or diverse high-Si silicates + {Fe} FeOx in pellets and sinter; much less commonly fayalite

{Mg}

Periclase/brucite

Periclase/brucite

{Mg, Al}

–

–

Spinel

{Mg, Al, Si, Ca}

–

–

Blast furnace slag (glassy); other Ca–Mg–Al-silicate glasses; melilite (akermanite–gehlenite)

{P, Ca}

Apatite

Apatite

{± , P, ±}

–

–

Diverse phosphates/phosphides

{Mn}

MnO-rich monoxide

{Si, Mn}

Mn-silicate

{Al}

Alumina (corundum); aluminium metal

{Ti}

TiO2 (rutile)

{Al, Si, Ti}

Ti–Al-silicate

{Si, Ti}

Ti-silicate

{Zn (Lα), ±}

–

–

ZnO (zincite); ZnFe-oxide (Zn-ferrite) + other Zn-dominated oxides with minor elements

{Na, Cl}

Halite (NaCl)

Halite (NaCl)

{± , Cl, ±}

–

–

Diverse chlorides; mixed pixels—chlorides on particle surfaces

{empty spectra}

Graphite

Graphite

All forms of carbon, including sample mounting medium