Temperature and common-ion effect on magnesium oxide (MgO) hydration

Amaral, Luís; Oliveira, I. R.; Salomão, R.; Frollini, Elisabete; Pandolfelli, V. C.

doi:10.1016/j.ceramint.2009.12.009

Cited by 141 publications

(97 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Physical damage caused by MgO hydration was evaluated using the measurements of the apparent volumetric expansion (AVE) [2,5,[13][14][15]. The AVE values were obtained by measuring the dimensions of the samples before and after being exposed to the hydration condition.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Chelants to inhibit magnesia (MgO) hydration

Amaral¹,

Oliveira

Bonadia³

et al. 2011

Ceramics International

Self Cite

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

“…[11][12][13][14][15] Nevertheless, the results attained are quite diverse due to differences in the magnesia source, purity, temperature, hydration time and the chemical environment where the hydration is performed.…”

Section: Introductionmentioning

confidence: 99%

Chelants to inhibit magnesia (MgO) hydration

Amaral¹,

Oliveira

Bonadia³

et al. 2011

Ceramics International

Self Cite

View full text Add to dashboard Cite

“…The aqueous dissolution of MgO and precipitation of magnesium hydroxide (Mg(OH)2) has been extensively studied [15][16][17]. Protonation (Eq.…”

Section: Hydrolysis Of Mgo and Dissolution Of Sf Influences The Formamentioning

confidence: 99%

Role of sodium hexametaphosphate in MgO/SiO2 cement pastes

Jia

Wang

et al. 2016

Cement and Concrete Research

View full text Add to dashboard Cite

The extent of reaction between magnesium oxide (MgO) and silica fume (SiO2) is normally limited and mixes require high water contents to give suitable rheology. The use of considerably lower water contents and the formation of magnesium silicate hydrate (M-S-H) gel as a binding phase is made possible by adding sodium hexametaphosphate (Na-HMP) to the mix water prior to the addition of MgO and SiO2. This results in the formation of extensive reaction products and cured samples with high compressive strength and low porosity. In this work, the effect of Na-HMP on the hydration of MgO/SiO2 mixes is investigated using high water to solids ratio samples to allow monitoring of pH and the solution chemistry during hydration. It is shown that a relatively small amount of Na-HMP inhibits the formation of Mg(OH)2 when MgO is hydrolyzed. It is proposed that this is due to adsorption of phosphate species on the MgO which inhibits the nucleation of the Mg(OH)2.. This gives rise to high Mg 2+ species in solution and elevated pH (>12) conditions relative to when Mg(OH)2 forms. In contrast, the phosphate does not suppress formation of M-S-H gel. In combination with the enhanced dissolution rate of SiO2 at high pH, M-S-H gel can form quickly without competition for Mg 2+ ions by Mg(OH)2 precipitation. Incorporating the optimum concentration of Na-HMP into the mix water therefore transforms the properties of cement paste and mortar samples formed by reacting MgO and SiO2.

show abstract

“…A consequência desse contato com a água na fase líquida ou vapor em temperaturas elevadas é a modificação da superfície das partículas sólidas, dando início à hidratação das mesmas [2][3][4][6][7][8][9][10][11]. As reações que descrevem esses processos são apresentadas nas Eqs.…”

Section: Introductionunclassified

“…Por exemplo, nos processos de extração e processamento do minério, o sínter de MgO passa por tratamento térmico a elevadas temperaturas, sendo possível reconstituir as imperfeições geradas na etapa de calcinação e obter cristais maiores, com menos contornos de grão e menor área superficial. Devido a isso, esse tratamento pode afetar diretamente a reatividade do óxido resultante [3]; 2) Presença de aditivos/impurezas nas composições refratárias: especialmente em concretos, a presença de aditivos (como dispersantes) e ligantes (cimento de aluminato de cálcio, alumina hidratável ou microssílica) também podem causar mudanças significativas na evolução da hidratação [11,[13][14][15]. Estes últimos conferem resistência mecânica aos concretos refratários durante as etapas iniciais de processamento.…”

Section: Introductionunclassified

Influência dos sais MgCl 2 e CaCl 2 no comportamento de hidratação do MgO

et al. 2018

View full text Add to dashboard Cite

INTRODUÇÃOO óxido de magnésio (MgO) ou magnésia é uma importante matéria-prima para a indústria de refratários e entre as diversas fontes disponíveis deste material, sínter, magnésia cáustica ou grãos eletrofundidos, isoladamente ou em combinação com alumina (Al 2 O 3 ) ou cromita (Cr 2 O 3 ), são os mais utilizados para tal finalidade. O potencial de aplicação do MgO em refratários se deve ao fato deste apresentar elevada refratariedade e contribuir para o aumento da resistência à corrosão destes produtos quando em contato com escórias alcalinas. Além disso, quando em combinação com o óxido de alumínio e exposto a temperaturas acima de 1200 °C, o MgO pode levar à formação de espinélio

show abstract

Temperature and common-ion effect on magnesium oxide (MgO) hydration

Cited by 141 publications

References 13 publications

Chelants to inhibit magnesia (MgO) hydration

Chelants to inhibit magnesia (MgO) hydration

Role of sodium hexametaphosphate in MgO/SiO2 cement pastes

Influência dos sais MgCl 2 e CaCl 2 no comportamento de hidratação do MgO

Contact Info

Product

Resources

About