Investigation on the reaction between MgO–CaO–CaF2 and Al–C powders to extract magnesium under atmospheric pressure

Zhang, Teng

doi:10.1016/j.jma.2019.03.001

Cited by 7 publications

(10 citation statements)

References 12 publications

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“…The weighed samples are mixed well by the ball milling process, and the weight ratio of ball to sample is 5:1 (YXQM-1L, MITR, Changsha, China). Based on our previous experiment results [23], in order to obtain activated sample sufficiently, the ball milling speed and time are fixed at 600 r/min, 5 h, respectively. During the milling process, sodium stearate (ball mill additives 6 Wt%) was added to the mixtures to improve ball grinding efficiency of reaction materials.…”

Section: Mechanically Activated Samples Preparationmentioning

confidence: 99%

“…Compared with the reducing agents ferrosilicon alloy and carbon, aluminum metal has stronger reducing power. Thus, lots of valuable research works have been focused on the reduction of MgO using the vacuum aluminothermic reduction method with a vacuum pressure of less than 20 pa [19][20][21][22][23]. Nevertheless, this method has some drawbacks; one is that the reduction process is performed under the lower vacuum pressure condition.…”

Section: Introductionmentioning

confidence: 99%

“…Here, we report the closed microwave aluminothermic reduction method to prepare magnesium and Mg-Al alloy directly from magnesia. In order to make full use of carbon resources and reduce the cost of magnesium production, the reaction between Al-C, Al-CaC 2 , and MgO-CaO is investigated as well based on our previous work [23]. Firstly, the electric and magnetic field intensity of the reaction device and the sample were calculated by using the computational simulation calculation software (ANSYS electronics desktop 2018) in order to obtain the best microwave heating conditions for the reaction sample.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Novel Approach to Prepare Magnesium and Mg-Al Alloy from Magnesia by Using the Closed Microwave Aluminothermic Method

Zhang

Wang

Niu

et al. 2023

Metals

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Herein, we report a novel approach to obtaining magnesium and nanocrystal Mg-Al alloy from magnesia using a closed microwave aluminothermic method in order to solve the problems of high energy consumption, high pollution, and low productivity in the process of magnesium and its alloy production. The main idea of the paper is to design a technique for the preparation of magnesium–aluminum alloy during the reduction process of MgO directly under atmospheric pressure. Based on this experimental idea, we have established a closed microwave aluminothermic reduction reactor. The great advantage of the reaction device is that it can make the reaction material heat up quickly to the reaction temperature in the microwave heating process and produce high-pressure magnesium vapor, which reacts with aluminum dramatically to form Mg-Al alloy under microwave irradiation. By the calculation of the electromagnetic field of the reaction device and sample using ANSYS electronics desktop 2018, the optimum microwave heating conditions for samples have been established. Based on the calculation results, we demonstrate that magnesium and its alloy are prepared successfully by using this method. In addition, the reduction rate of MgO is greatly improved, which is higher up to 79.97 Wt% when the reduction time is 30 min, at 1273 K, and the Mg2Al3 and MgAl alloy is formed during the reduction process as well. Moreover, the formation mechanism of Mg-Al alloy during the reduction process under microwave irradiation was discussed further. Our findings could provide a new approach, insights, and research directions to obtain magnesium and Mg-Al alloy directly from magnesia under normal pressure.

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Section: Mechanically Activated Samples Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Novel Approach to Prepare Magnesium and Mg-Al Alloy from Magnesia by Using the Closed Microwave Aluminothermic Method

Zhang

Wang

Niu

et al. 2023

Metals

Self Cite

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“…In the traditional industrial production of magnesium by Pidgeon process, it was often necessary to add a certain amount of calcium fluoride to the material to improve the reduction rate of magnesium oxide in the reduction process. Previous studies [17][18][19] had shown that CaF2 could increase the reaction energy on the surface of oxide, accelerate the interaction between materials, and reduce the reaction temperature. However, due to the excessive CaF2 content, the reduced slag would bond to the reduction tank in a semi molten state, which made it difficult to slag out.…”

Section: Fig 1 Comparison Of Improved Process and Pidgeon Processmentioning

confidence: 99%

“…Previous studies [17,27] had found that the addition of CaF 2 could increase the reduction rate and shorten the equilibrium time, that was, the addition of CaF 2 could increase the reduction rate of MgO in the same reduction time. Most of the previous studies focused on the traditional Pidgeon process and aluminothermal process, which was characterized by the reduction process in vacuum, reduction temperature not more than 1250℃, and calcium fluoride addition not more than 6% [18,19]. In this paper, magnesium was extracted by prefabricated pellets in flowing argon, so the effect of CaF 2 on the reduction rate of magnesium oxide was studied.…”

Section: Effect Of Caf 2 On Reduction Rate Of Mgo In Prefabricated Pelletsmentioning

confidence: 99%

The effect of calcium fluoride on extracting magnesium from magnesite and calcium carbonate by silicothermal reduction in flowing argon

Guo

Han

et al. 2022

J min metall B Metall

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At present, the production of magnesium is mainly carried out semi-continuously with ferrosilicon as reducing agent under high temperature and high vacuum. In order to continuously produce magnesium, anew method of extracting magnesium from low-grade magnesite and calcium carbonate by silicothermal method in flowing inert gas was proposed. The effects of calcium fluoride(CaF2)on decomposition rate, decomposition kinetics, reduction rate of magnesia and crystal type of dicalcium silicate in reduction slag were investigated in the paper. The experimental results showed that calcium fluoride could accelerate the decomposition of carbonate, and had no side effect on the calcined products. In addition, the analysis results of DTA curves showed that calcium fluoridecould reduce the decomposition reaction activation energy and the reaction temperature of carbonatein the prefabricated pellets. The results of reduction experiments showed that proper calcium fluoridecould promote the reduction rate of magnesia, and in the temperature range of 1250? ~ 1350?, with same timeframe, the corresponding calcium fluoride contents were5%, 3% and 1% respectively when the reduction rate reached the maximum. Excessive calcium fluoride could reduce the reduction rate of magnesia, but it couldpromote the transformation of dicalcium silicate to ? phase in the reduction slag.

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The Preparation of Magnesium from Magnesia by Using Atmospheric Microwave Al-C Reduction Method

Zhang,

Wang,

Niu

et al. 2024

JOM

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Investigation on the reaction between MgO–CaO–CaF2 and Al–C powders to extract magnesium under atmospheric pressure

Cited by 7 publications

References 12 publications

Novel Approach to Prepare Magnesium and Mg-Al Alloy from Magnesia by Using the Closed Microwave Aluminothermic Method

Novel Approach to Prepare Magnesium and Mg-Al Alloy from Magnesia by Using the Closed Microwave Aluminothermic Method

The effect of calcium fluoride on extracting magnesium from magnesite and calcium carbonate by silicothermal reduction in flowing argon

The Preparation of Magnesium from Magnesia by Using Atmospheric Microwave Al-C Reduction Method

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