Alite inclusions

The bulk composition affects the relative amounts of phases, the LSF, SR and AR affecting primarily the ratios of alite to belite, silicate phases to interstitial material and aluminate to ferrite phase, respectively. An LSF that is too high, either absolutely or in relation to the burning conditions, also gives rise to an excessive content of free lime. Belite may occur in such clinkers only as inclusions in alite. [Pg.103]

The possibilities of using free lime or periclase as expansive agents have also been investigated. Kawano cl al. (K50) and Long (L49) described clinkers in which substantial proportions of free lime are present as inclusions in alite. In both ca.ses, the raw mix included anhydrite. Long investigated and described the processes by which this microstructure was formed. [Pg.337]

Alite crystallizing from the melt has very differentiated morphology. Frequently of very disturbed constitution. Maki [42] distinguishes two periods of alite crystals growth quick and in condition close to equilibrium. The crystals formed during the quick growth period contains the inclusions of liquid phase. They are usually in the core of crystals. In the similar conditions the inclusions of small crystals of C2S and CaO as well as air bubbles can be formed. The latter, according to Maki, as... [Pg.52]

Colorless belite, according to Lee (1983), can occur as very small inclusions in alite and contains very little impurity. Large-crystal, ringlike belite nests (from coarse alkali feldspar) are also colorless because of iron-oxide deficiency. These occurrences of belite, therefore, do not reflect the cooling rate. Consequently, Ono (1978) recommends color observation of roughly 20 pm belite crystals in order to judge the cooling rate. [Pg.60]

Large alite with small inclusions of fine ferrite and aluminate crystals alite is mostly variety Result of burning at 1450°C (Maki and Goto, 1982)... [Pg.73]

Coarser alite (average = 50 to 60 pm) with a few large inclusions Longer coal flame (Kramer, 1960)... [Pg.74]

Zoned alite with dotlike inclusions Clinker burned with long flame (Ono, 1981)... [Pg.76]

Pseudomorphic crystals after primary alite contain fine inclusions or margins of ferrite, belite, and free lime Moderate reduction, and introduction of iron into alite lattice resulting in instability and decomposition (Woermann, 1960)... [Pg.77]

Intimate mixture of belite and dicalcium ferrite on alite lattice planes free-lime crystals with inclusions of 2CaO Fep3 Low temperature re-oxidation (Long, 1982b)... [Pg.78]

Alite with ultra-fine particles under 0.5 pm (inclusions) Excess solid solution (Ono, 1995)... [Pg.78]

Photograph 7-15 Euhedral to subhedral, zoned, yellowish tan alite dark, round belite with typical multidirectional lamellae and a well-differentiated matrix of aluminate (C3A) and ferrite (C AF). Small belite inclusions in alite. Epoxy-filled pore at bottom of photo. Coal-fired kiln, wet-process, 1000 tons/day, 38 MPa coarse seashell feed (30% greater than 75 pm). (S A6635)... [Pg.79]

Segregation of belite, digitation, gamma polymorph, exsolution in alite, reduced areas with metallic inclusions and oldhamite (Ca, MnS) variation in phase percentages Assimilation of high silica and alumina coal ash (Kihara, 1988)... [Pg.84]

Relatively large belite inclusions in elite, large belite crystals (45 pm) Abundance of coarse quartz in feed belite and alite became much smaller upon use of finely ground friable silica (Dorn, 1980)... [Pg.85]

Tiny belite inclusions suggestive of lamellae in alite Deficient air suppiy in sintering zone (Gille and others, 1965)... [Pg.86]

Belite inclusions in alite Relatively large (12 to 13 pm) In clinker made with quartz sand 8 pm in clinker made with sponge-silica (Dorn, 1980) residual original belite (Brown, 1948)... [Pg.87]

Photograph 7-26 Experimental laboratory burn with raw mix containing quartz (44-75 pm) as a silica source. Average alite crystal size = 44 pm. 1000°C for 30 min, 1425°C for 10 min. Very rapid temperature change. Note abundant free lime inclusions in alite. Clinker courtesy of Joe Garcia, Capitol Cement, San Antonio, Texas. (S A6646)... [Pg.88]

Photograph 7-80 Strongly zoned, tan alite with free-lime inclusions and round, coarsely lamellar belite with tan cores, the latter believed to have a relatively low calcium-to-silicon ratio. Coarse seashells in feed. [Pg.111]

Photograph 9-6 Nital-etched, broken surface of clinker, revealing belite lamellar structure. Note small belite inclusion in alite crystal (left center). (S A6732)... [Pg.130]

Efch reactivity variations (specify etch and length of time). Crystal morphology crystal surface characteristics (depth of alteration) internal structure tendency for coarse cannibalism (masses greater than 5 times the average alite crystal size) inclusions. Size and abundance variations within and between clinkers. [Pg.165]

The use of X-ray diffraction (XRD) data can clearly be supportive to microscopy in almost all materials investigations. One obvious advantage of XRD analysis is that it is a reliable mode of identification and quantification for almost all of the major phases commonly seen in raw feed, clinker, and cement. However, XRD analysis suffers one major disadvantage it cannot tell you where, in the examined mass of clinker, the belite is located or how the belite is related to alite. XRD analysis can indicate the presence of belite and, with some calibrated standards, the amoimts of belite polymorphs, but only the microscope can tell you that the belite occurs mostly as decomposition of alite crystals or that the belite occurs only as inclusions in alite. XRD analysis may indicate the presence and quantity of more than... [Pg.169]

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