The role of Li2O, MgO and CuO on SO3 activated clinkers

Boháč, Martin; Kubátová, Dana; Kotlánová, Michaela; Khongová, Ingrid; Zezulová, Anežka; Novotný, Radoslav; Palou, Martin; Staněk, Theodor; Všianský, Dalibor

doi:10.1016/j.cemconres.2021.106672

Cited by 10 publications

(4 citation statements)

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“…Recently, the entry of Cu into the clinker phases and the influence of CuO on clinker formation 18,19 and the influence of SO 3 in combination with individual selected cations (Cu, Mg and Li) on the properties of belite-rich clinker was studied. 20 Computer simulation techniques and theoretical calculations confirmed that Cu tends to replace mainly Fe atoms. Cu also replaces Ca atoms more readily than Si atoms in the main clinker phases.…”

Section: Introductionmentioning

confidence: 92%

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The effect of the combined addition of copper, lithium and sulphur on the formation of Portland cement clinker

Staněk,

Rybová,

Boháč

et al. 2024

Journal of Microscopy

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Both copper and lithium act as strong fluxes and lower the temperature of the clinker melt formation. Sulphur promotes the stabilisation of more hydraulically active modification of alite M1. It is expected that this combination could produce an alite clinker at significantly lower temperatures with high quality technological parameters. In this paper, the effect of combined oxides of copper, lithium and sulphur addition on the phase composition and clinker structure of Portland cement was investigated. The reference raw meal was prepared from common cement raw materials. Each of the mentioned oxides was added to the reference raw meal in two different concentrations, and 8 combinations were prepared. Chemically pure compounds (NH4)2SO4, CuO and Li2CO3 were used as a source of these oxides. The raw meals were burned to equilibrium at 1450°C. Their phase composition was determined by X‐ray diffraction analysis, the microstructure was monitored by optical microscopy, and the microchemistry of the clinker phases was observed by electron microscopy with EDS analysis. It was found that in samples with high lithium or copper content, there is an increase in belite and free lime at the expense of alite. The combination of Cu + Li has the most negative effect, followed by Li alone and Cu alone. The higher SO3 content slightly offsets this negative effect.

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Section: Introductionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

The effect of the combined addition of copper, lithium and sulphur on the formation of Portland cement clinker

Staněk,

Rybová,

Boháč

et al. 2024

Journal of Microscopy

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“…One of the current areas of cement research is lowenergy cements activated by various dopants or combinations of dopants. [10][11][12][13][14][15] The content and reactivity of C 4 AF changes significantly due to fluxes and mineralisers. A deeper understanding of the mobility of individual ions and compounds is needed to support recent knowledge of mechanisms of C 4 AF hydration.…”

Section: Introductionmentioning

confidence: 99%

“…One of the current areas of cement research is low‐energy cements activated by various dopants or combinations of dopants 10–15 . The content and reactivity of C 4 AF changes significantly due to fluxes and mineralisers.…”

Section: Introductionmentioning

confidence: 99%

Early hydration of C₄AF with silica fume and its role on katoite composition

Boháč,

Zezulová,

Krejčí Kotlánová

et al. 2024

Journal of Microscopy

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C4AF is considered the least reactive main clinker phase, but its reactivity may be affected by adding supplementary cementitious materials (SCMs). Pure C4AF was synthesised in a laboratory furnace, and the role of silica fume without gypsum on its early hydration properties was monitored. Burning was carried out in four stages to achieve 99% purity of C4AF. Heat flow development was monitored by isothermal calorimetry over 7 days of hydration at 20°C and 40°C. The role of silica fume on hydrogarnet phase katoite (Ca3Al2(SiO4)3 – x(OH)4x x = 1.5–3) formation during early hydration was studied. Rapid dissolution of C4AF, formation of metastable C‐(A,F)‐H and its conversion to C3(A, F)H6 was evidenced by isothermal calorimetry as a large exotherm. Changes in microstructure during early hydration were documented by SE micrographs, EDS point analyses, X‐ray mapping and line scans by SEM‐EDS. The phase composition was characterised by DTA‐TGA and QXRD after 7 days of hydration. The katoite diffraction pattern is similar for the reference sample and sample with silica fume, but substitution in its structure can be revealed by X‐ray microanalyses. The composition of katoite is variable due to the various extent of substitution of 4OH− by SiO44− due to silica fume.

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