larnite

larnite

[′lär‚nīt]
(mineralogy)
β-Ca2SiO4 A gray mineral that is a metastable monoclinic phase of calcium orthosilicate, stable from 520 to 670°C. Also known as belite.

larnite

A mineral which is a major constituent of portland cement; beta dicalcium silicate.
References in periodicals archive ?
The analysis showed that the composition of the original ash sample included mainly quartz, lime, anhydrite, calcite and smaller amounts of orthoclase, periclase, gehlenite, larnite, merwinite, pseudowollastonite, hematite, ettringite, melilite and dolomite (Table 2).
The resonance lines at -71.5 and -107.3 ppm arise from larnite ([Ca.sub.2]Si[O.sub.4]) and quartz, respectively [18].
From XRD analysis, mineral phases of portlandite, calcium carbonate, larnite, and ettringite were found.
The XRD results showed that the BOF slag constitute of magnesium ferrite (Mg[Fe.sub.2][O.sub.4]) and larnite ([Ca.sub.2]Si[O.sub.4]).
The most characteristic minerals are the following: wustite (FeO), which is well crystallized into round and oval-shaped particles, similarly crystallized lamellar larnite with some allite ([C.sub.2]S + [C.sub.3]S), both of which are embedded in a microcrystalline matrix of brownmillerite ([C.sub.4]AF), and mayenite ([C.sub.12][A.sub.14][O.sub.33]).
The following mineralogical components resulted from X-Ray diffraction analysis of slag: wustite FeO; calcium ferrite Ca[Fe.sub.2][O.sub.4]/(CF); srebrodolskite [Ca.sub.2][Fe.sub.2][O.sub.5]/([C.sub.2]F); larnite [Ca.sub.2]Si[O.sub.4]/([C.sub.2]S); alite [Ca.sub.3]Si[O.sub.5]/([C.sub.3]S); mayenite [Ca.sub.12][Al.sub.14][O.sub.33]/[C.sub.12][A.sub.7]; brownmillerite [Ca.sub.2][(Al,Fe).sub.2][O.sub.5]/[C.sub.4]AF.
All the hydration products of the specimens showed some weak peaks, which can be identified as omphacite ((NaCa) (AlMg)Si[O.sub.6]), larnite ([Ca.sub.2]Si[O.sub.4]), poorly crystalline C-S-H, and calcite (CaC[O.sub.3]).
In addition, all SCP formulations showed the presence of ettringite [[Ca.sub.6][Al.sub.2][(S[O.sub.4]).sub.3][(OH).sub.12] x 26([H.sub.2]O)], hatrurite [[Ca.sub.3]Si[O.sub.5]], and larnite [[Ca.sub.2](Si[O.sub.4])] at 1 and 7 days.
The content of six main components: lime CaO, anhydrite CaS[O.aub.4], quartz Si[O.sub.2], calcite CaC[O.sub.3], periclase MgO and larnite [Ca.sub.2]Si[O.sub.4] was determined.
Furthermore, as shown in Figure 1, the mineralogical compounds detected in the LF slag could be attributed to mayenite (12CaO x 7[Al.sub.2][O.sub.3], [Ca.sub.12][Al.sub.14][O.sub.33], and [C.sub.12][A.sub.7]), periclase (MgO), gehlenite (2CaO x [Al.sub.2][O.sub.3] x Si[O.sub.2], [Ca.sub.2][Al.sub.2]Si[O.sub.7]), larnite ([beta]-2CaO x Si[O.sub.2], [beta]-[Ca.sub.2]Si[O.sub.4]), shannonite ([gamma]-2CaO x Si[O.sub.2], [gamma]-[Ca.sub.2]Si[O.sub.4]), and tricalcium aluminate (3CaO x [Al.sub.2][O.sub.3], [Ca.sub.3][Al.sub.2][O.sub.6], and [C.sub.3]A).
Initial ash contains quantitatively fixable amounts of lime CaO, quartz Si[O.sub.2], anhydrite CaS[O.sub.4], calcite CaC[O.sub.3], larnite [Ca.sub.2]Si[O.sub.4] (dicalcium silicate 2CaO x Si[O.sub.2]) and periclase MgO.
CaO, MgO, quartz and larnite ([beta]-[Ca.sub.2]Si[O.sub.4]) were the main phases in the calcinated samples.