Synthesis of MgCO3 microcrystals at 160°C starting from various magnesium sources

Xing, Zheng; Qin, Hao; Ju, Zhicheng; Xu, Liqiang; Qian, Yitai

doi:10.1016/j.matlet.2010.03.042

Cited by 22 publications

(17 citation statements)

References 11 publications

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“…The TGA results for the sediment treated by MgO only are also presented for comparison purposes. In previous studies that used TGA analyses to evaluate the hydration and carbonation of MgO, brucite (Mg(OH) 2 ), and magnesite (MgCO 3 ) were reported to decompose at around 300–500 and 500–800°C, respectively . In this study, we observed changes in masses at these temperature ranges, which confirmed the existence of brucite and magnesite in our samples.…”

Section: Resultssupporting

confidence: 88%

MgO‐Based Binder for Treating Contaminated Sediments: Characteristics of Metal Stabilization and Mineral Carbonation

Hwang

Seo

Quang

et al. 2013

CLEAN Soil Air Water

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We developed a novel mixed binder of MgO (magnesia) and supplementary cementitious materials that can solidify sediments contaminated with heavy metals as well as store CO2 through mineral carbonation reactions. The optimal MgO‐based binder consisted of MgO, lime (L), fly ash (FA), and blast furnace slag (BFS) with a formula of MgO0.5–(L0.1–(FA0.4BFS0.6)0.9)0.5. The binder exhibited a compressive strength of 11.9 MPa, which was similar to that of Portland cement. Sequential extraction of treated sediments showed that the stabilization capacity of the MgO‐based binder for heavy metals (Cu, Cd, Ni, Pb, and Zn) was two times higher than that of PC. Results also show that more than 50% of the stabilized heavy metals existed within very persistent solid phases that were not disintegrated during the final step of the sequential extraction procedure using a HNO3/HClO4/HF solution. The hydration products of MgO that contributed to strength development and metal stabilization included brucite (Mg(OH)2), magnesium–silicate–hydrates (M–S–H), and lansfordite (MgCO3 · 5 H2O). Lansfordite was a major carbonation product in the treated sediments. By use of thermogravimetric analyses, we found that 58 kg of CO2 could be sequestrated within the solidified sediment when a ton of dredged sediment was treated.

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Section: Resultssupporting

confidence: 88%

MgO‐Based Binder for Treating Contaminated Sediments: Characteristics of Metal Stabilization and Mineral Carbonation

Hwang

Seo

Quang

et al. 2013

CLEAN Soil Air Water

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“…Samples with compositions x > 0.6 were prepared using 0.1 M Na 2 CO 3 and 0.1 M mixed (Ca 2+ + Mg 2+ ) chloride solutions. The calcite sample was obtained from Fisher Chemicals and dried at 250°C for 20 h. Magnesite was synthesized by urea hydrolysis using a hydrothermal method previously reported (Xing et al, 2010). A 30 ml aqueous solution containing 1.40 g of MgCl 2 Á6H 2 O and 4.05 g of urea loaded in an autoclave (50 ml capacity) was hydrothermally treated for 30 h at 160°C.…”

Section: Sample Synthesismentioning

confidence: 99%

Energetic and structural studies of amorphous Ca1−Mg CO3·nH2O (0 ⩽x⩽ 1)

Radha¹,

Fernández-Martı́nez

et al. 2012

Geochimica et Cosmochimica Acta

127

228

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“…The present study deals with the solventmediated transformation (Cardew and Davey, 1985) of hydromagnesite to magnesite during heating cycles over a range of temperature (120À180ºC) in excess of the boiling point of water. For the three temperatures under investigation (120, 150 and 180ºC) the transformation of hydromagnesite to magnesite (Sandengen et al, 2008;Xing et al, 2010) is analysed by applying the Avrami theory to isothermal solvent-mediated processes (Prigiobbe and Mazzotti, 2013). The transformation kinetics and the activation energy of the process are estimated using the so-called ''time to a given fraction'' method (Putnis, 1992).…”

Section: Introductionmentioning

confidence: 99%

Kinetics of the solvent-mediated transformation of hydromagnesite into magnesite at different temperatures

2014

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The process of transforming hydromagnesite to magnesite is analysed in the context of the theory of solvent-mediated transformations. A series of experiments at 120, 150 and 180ºC with different heating times was designed to determine, by powder X-ray diffraction, the amount of magnesite generated as a function of time. The aqueous-phase composition was monitored by inductively coupled plasma-mass spectrometry and carbonate alkalimetry. From the analytical data, the evolution of saturation indexes with respect to both phases was determined using the geochemical code PHREEQC. Finally, two different methods were applied to obtain the activation energy of the process and a TTT (TemperatureTransformation-Time) graph was constructed to define suitable conditions in which to obtain magnesite.

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Synthesis of MgCO3 microcrystals at 160°C starting from various magnesium sources

Cited by 22 publications

References 11 publications

MgO‐Based Binder for Treating Contaminated Sediments: Characteristics of Metal Stabilization and Mineral Carbonation

MgO‐Based Binder for Treating Contaminated Sediments: Characteristics of Metal Stabilization and Mineral Carbonation

Energetic and structural studies of amorphous Ca1−Mg CO3·nH2O (0 ⩽x⩽ 1)

Kinetics of the solvent-mediated transformation of hydromagnesite into magnesite at different temperatures

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