Kinetics of extracting magnesium from mixture of calcined magnesite and calcined dolomite by vacuum aluminothermic reduction

Fu, Daxue; Wang, Yaowu; Peng, Jianping; Di, Yuezhong; Tao, Shaohu; Niu, Feng

doi:10.1016/s1003-6326(14)63133-2

Cited by 30 publications

(8 citation statements)

References 14 publications

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“…Occurrences and industrial mineral deposits, primarily in North Greece, are examined in relation to their uses, such as feldspars, pozzolan, pumice, kaolin, zeolites, quartz, gypsum, and white carbonates. Fu et al [91] Kinetics of extracting magnesium from mixture of calcined magnesite and calcined dolomite by vacuum aluminothermic reduction…”

Section: Study Of Mineral Composition Microstructure Thermal Expansmentioning

confidence: 99%

Review on the elaboration and characterization of ceramics refractories based on magnesite and dolomite

Sadik

Moudden

Bouari

et al. 2016

Journal of Asian Ceramic Societies

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One of the most important elements of furnaces, boilers and other heating units is the structure (lining), usually made of silica-alumina, basic or special refractories. The basic refractories are materials that are increasingly in demand and whose manufacturing involves necessarily the use of MgO and CaO. In this article, the description and characterization of magnesite (MgCO 3) and dolomite (Mg,Ca(CO 3) 2) and their contribution in industrial ceramics-refractories have been reviewed.

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Section: Study Of Mineral Composition Microstructure Thermal Expansmentioning

confidence: 99%

Review on the elaboration and characterization of ceramics refractories based on magnesite and dolomite

Sadik

Moudden

Bouari

et al. 2016

Journal of Asian Ceramic Societies

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“…Since the Pidgeon process was put forward in 1941, it has developed rapidly in China due to its simple technology and flexible scale, but it has also increasingly highlighted the problems of high labor intensity, interrupted production and high energy consumption [9][10][11]. Therefore, some new processes such as aluminothermal process [12], carbothermal process [13,14], MTMP process [15] have been studied, which also provide new ideas for industrial magnesium production.…”

Section: Introductionmentioning

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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“…Based on the analysis above, searching for a reducing agent with lower reduction temperature and faster reduction rate than ferrosilicon is an alternative way to solve this problem. Al and Al(46.7%)-Si(45.7%)-Fe(7.6%) alloy were considered as a promising substitute materials for FeSi [10][11][12][13][14]. The previous research results showed that these reduction agents can decrease the reduction temperature.…”

Section: Introductionmentioning

confidence: 99%

“…The mechanism of magnesium oxide reduction by aluminum and Al-Si-Fe alloy is different from that of ferrosilicon. [10]. Although the reduction process of magnesium oxide by Al and Al-Si-Fe alloy have many advantages, the higher price of these reducing agents makes it difficult to be industrialized.…”

Section: Introductionmentioning

confidence: 99%

Phase transformation involved in the reduction process of magnesium oxide in calcined dolomite by ferrosilicon with additive of aluminum

Wang

2020

Green Processing and Synthesis

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AbstractMetal magnesium is mainly produced from the calcined dolomite by the silicothermic production. However, in this process, the reduction temperature is higher while the reaction speed is slow, which results in higher energy consumption and serious environmental problems. In this paper, adding aluminum into the ferrosilicon reducing agent is expected to lower the reaction temperature so as to solve the problems above. The phase transition involved in the whole reduction process including with and without aluminum addition were investigated in details by theoretical calculation and experimental research. The influence of aluminum on the magnesium oxide reduction path was analysis to clarify the internal mechanism. The results show that aluminum added into the ferrosilicon would first react with magnesium oxide to form magnesium vapor and alumina under vacuum pressure of 10 Pa when the temperature rises to 720°C. Then, calcium aluminate would be formed by the reaction of aluminum oxide and calcium oxide. Once the temperature reaches 1150°C, silicon begins to reduce the magnesium oxide to create the silicon oxide that will finally react with calcium oxide to form calcium silicate. When the temperature rises above 1150°C, both the aluminum and silicon will participate in the reduction of magnesium oxide. In the process of heating up, the mixture of aluminum, ferrosilicon and calcined dolomite forms Mg2Al4Si5O18 and Ca3Al2(OH)12 phase with the components in calcined dolomite. Mg2Al4Si5O18 and Ca3Al2(OH)12 phase finally form Ca12Al14O33 phase. The interaction between aluminum and ferrosilicon in the mixture is less; the mixture of aluminum and ferrosilicon first forms Al3FeSi2 phase, and finally has the trend of forming Al4.5FeSi phase. There is a great difference between the phase transformation of aluminum in the mixture of aluminum, ferrosilicon and calcined dolomite and that of aluminum in the mixture of aluminum and ferrosilicon.

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Kinetics of extracting magnesium from mixture of calcined magnesite and calcined dolomite by vacuum aluminothermic reduction

Cited by 30 publications

References 14 publications

Review on the elaboration and characterization of ceramics refractories based on magnesite and dolomite

Review on the elaboration and characterization of ceramics refractories based on magnesite and dolomite

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

Phase transformation involved in the reduction process of magnesium oxide in calcined dolomite by ferrosilicon with additive of aluminum

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