Reaction Mechanism and Kinetic Analysis of the Decomposition of Phosphogypsum via a Solid-State Reaction

AbstractNon-isothermal reaction mechanism and kinetic analysis for the synthesis of monoclinic lithium zirconate (m-Li2ZrO3) were investigated by processing of TG-DTA, along with XRD, DLS, and HRTEM. For this purpose, the solid-state reaction of Li2CO3 with ZrO2 was carried out by TG-DTA at different heating rates (10, 20, and 30 °C/min) from room temperature to 1100 °C. The thermal data was used to calculate the kinetic parameters by two types of isoconversional methods: Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS). The reaction mechanism was determined by the model-fitting method, applying the Coats-Redfern (CR) approximation to the different solid-state reaction models. The results confirmed the formation of pure m-Li2ZrO3, consists of semispherical particles of about 490 nm, using a very short reaction time. The average activation energy obtained by FWO and KAS methods were 274.73 and 272.50 kJ/mol, respectively. It was found that the formation of m-Li2ZrO3 from Li2CO3 with ZrO2 is governed by the three-dimensional diffusion mechanism. Based on these results, a microscopic reaction model of the formation of m-Li2ZrO3 was proposed.

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Interdiffusion kinetics and solid-state reaction mechanism between Cr2O3 and calcium ferrite based on diffusion couple method

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2021.158754 ◽

2021 ◽

Vol 865 ◽

pp. 158754

Author(s):

Bojian Chen ◽

Tao Jiang ◽

Mi Zhou ◽

Lin Li ◽

Jing Wen ◽

...

Keyword(s):

Reaction Mechanism ◽

Solid State ◽

Diffusion Couple ◽

Solid State Reaction ◽

Calcium Ferrite ◽

Interdiffusion Kinetics ◽

Couple Method

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Study of the reaction mechanism between electroless Ni–P and Sn and its effect on the crystallization of Ni–P

Journal of Materials Research ◽

10.1557/jmr.2003.0002 ◽

2003 ◽

Vol 18 (1) ◽

pp. 4-7 ◽

Cited By ~ 28

Author(s):

Y. C. Sohn ◽

Jin Yu ◽

S. K. Kang ◽

W. K. Choi ◽

D. Y. Shih

Keyword(s):

Reaction Mechanism ◽

Solid State ◽

Solid State Reaction ◽

Crystallization Temperature ◽

Low Temperatures ◽

Transformation Temperature ◽

The Self ◽

Heat Of Reaction ◽

Solder Reaction ◽

Electroless Ni

The reaction mechanism between electroless Ni–P and Sn was investigated to understand the effects of Sn on solder reaction-assisted crystallization at low temperatures as well as self-crystallization of Ni–P at high temperatures. Ni3Sn4 starts to form in a solid-state reaction well before Sn melts. Heat of reaction for Ni3Sn4 was measured during the Ni–P and Sn reaction (241.2 J/g). It was found that the solder reaction not only promotes crystallization at low temperatures by forming Ni3P in the P-rich layer but also facilitates self-crystallization of Ni–P by reducing the transformation temperature and heat of crystallization. The presence of Sn reduces the self-crystallization temperature of Ni–P by about 10 °C. The heat of crystallization also decreases with an increased Sn thickness.

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