Development and field application of a modified magnesium slag-based mine filling cementitious material

Ruan, Shishan; Zhu, Mengbo; Shao, Chengcheng; Xie, Lei

doi:10.1016/j.jclepro.2023.138269

Cited by 25 publications

(6 citation statements)

References 74 publications

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“…Currently, the filling materials employed in coal mine goaf filling mainly include gangue, paste, and high-moisture materials. However, they suffer from disadvantages such as insufficient supply of gangue aggregates, low filling rates, and high investment costs (Cai et al, 2019;Li et al, 2023;Ruan et al, 2023;Shi et al, 2019;Zhao et al, 2020). Application of waste straw as filling material in coal mine goafs not only helps mitigate surface subsidence but also promotes residual coal conversion into methane.…”

Section: Introductionmentioning

confidence: 99%

Field conditions for the synergistic increase of biomethane in the goaf of coal mines filled with corn straw

Li,

Guo,

Zhang

et al. 2024

GCB Bioenergy

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Synergistic fermentation of coal and corn straw is an effective tool to increase biomethane production. However, a large gap exists between the biomethane production conditions of corn straw filling coal mine goafs and laboratory experiments. In order to determine the effect of the field environment on synergistic biomethane production, biomethane production experiments with coal and corn straw were carried out under different conditions to find the key factors restricting the potential of biomethane production. The obtained results showed that various bacterial sources had significant influences on the biomethane production of coal and corn straw, and domesticated bacterial sources provided fermentation systems with more efficient biomethane production capacities than mine water sources. Biomethane production of coal and corn straw was relatively high under mixed conditions, but it was also promoted under unmixed conditions. Different inorganic minerals had different effects on synergistic biomethane production, which varied. For example, calcite, montmorillonite, and kaolin are common minerals in coal‐bearing strata that significantly enhance synergistic biomethane production of coal and corn straw. However, pyrite was found to significantly inhibit the synergistic biomethane production effect of coal and corn straw. Highly metamorphosed anthracite coal also presented biomethane production potential when stimulated by corn straw as a carbon source. The obtained results revealed the influences of different field conditions on the biomethane production of coal and corn straw and provided a reference for the field application of corn straw filling in coal mine goafs.

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Section: Introductionmentioning

confidence: 99%

Field conditions for the synergistic increase of biomethane in the goaf of coal mines filled with corn straw

Li,

Guo,

Zhang

et al. 2024

GCB Bioenergy

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“…With this application, magnesium metal production costs will also be reduced; it will contribute to the reduction of cement production costs, it will enable more economical and long-lasting use of cement raw material resources and an environmentally friendly green product will be obtained as a result of the reduction in CO2 emissions. More than 1,000,000 tons of magnesium metal were produced in the world in 2020, and 8,500,000 tons of magnesium slag were obtained during the production of this material [8]. The increase in the magnesium crisis during the pandemic period indicates that the magnesium production rate will increase in the coming years, and new production facilities will be opened.…”

Section: Introductionmentioning

confidence: 99%

Effect of Thermal Activation on the Mineralogical Structure of Magnesium Slag

Korkmaz

2024

IJCESEN

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Magnesium slag's production process is similar to the Portland cement production process. The raw material used is carbonate-containing dolomite, and is calcined in a rotary kiln at 850-900 oC. Afterwards, ferrosilicon and fluorite raw materials are added to the calcined material, they are ground together and turned into pellets, and then they are reduced at a temperature close to the firing temperature of Portland cement clinker (1250-1350 oC) to obtain crown magnesium and magnesium slag. The reduction time of pellet material in reduction furnaces is 12 hours. During this period, almost all of the magnesium minerals in the mixture material are reduced and taken as crown magnesium metal. The remaining material, described as magnesium production slag (reduction furnace waste), consists of Alite (C3S), Belite (C2S), Celite (C3A) and C4AF minerals contained in Portland cement clinker. Some of the minerals contained in Portland cement clinker in the rotary kiln are formed at temperatures below 1400 °C, which is the clinker firing temperature. The only difference other than the firing temperature is that after the Portland cement clinker is fired in the rotary kiln, the clinker is cooled rapidly, increasing the alite (C3S) crystals formed in its structure and preventing the alite minerals from turning back into belite (C2S) minerals. This study produced magnesium slags at different temperatures (1200-1350 oC) by thermal activation method in an industrial environment. The Bogue and XRD methods calculated the mineral phase amounts of the products produced.

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“…More than 6 tons of magnesium slag is produced when smelting 1 ton of magnesium metal on average, and it is accompanied by nearly 30 tons of CO 2 and various types of flue gas emissions [3], which seriously pollute the environment of the area where it is located [4]. At present, there is no complete treatment technology for magnesium slag to enable its industrial utilization, which leads to massive accumulation of magnesium slag in the open air [5]. This not only takes up considerable land resources and damages the ecological environment, but also poses a threat to human health [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…Whilst the desulfurization performance of the original magnesium slag is poor, a calcium conversion rate of up to 73.7% can be reached after mixing with additives or modification [34]. Magnesium slag, like other solid wastes, can also be used for mine filling [5,35,36] or road base material [37][38][39][40][41][42]. Numerous studies have conducted extensive research into other industrial solid wastes, such as granulated blast furnace slag [43][44][45], steel slag [46], red mud [47] and so on [48][49][50], which provide guidance for the utilization of the corresponding tailings and slag.…”

Section: Introductionmentioning

confidence: 99%

Structural Characteristics and Cementitious Behavior of Magnesium Slag in Comparison with Granulated Blast Furnace Slag

Lu,

Zhao,

Zhang

et al. 2024

Materials

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Magnesium slag is a type of industrial solid waste produced during the production of magnesium metal. In order to gain a deeper understanding of the structure of magnesium slag, the composition and microstructure of magnesium slag were investigated by using characterization methods such as X-ray fluorescence, particle size analysis, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. In addition, the state of Si occurrence in magnesium slag was analyzed using a solid-state nuclear magnetic resonance technique in comparison with granulated blast furnace slag. An inductively coupled plasma-optical emission spectrometer and scanning electron microscope with energy dispersive X-ray spectroscopy were used to characterize their cementitious behavior. The results show that the chemical composition of magnesium slag mainly includes 54.71% CaO, 28.66% SiO2 and 11.82% MgO, and the content of Al2O3 is much lower than that of granulated blast furnace slag. Compared to granulated blast furnace slag, magnesium slag has a larger relative bridging oxygen number and higher [SiO4] polymerization degree. The cementitious activity of magnesium slag is lower compared to that of granulated blast furnace slag, but it can replace part of the cement to obtain higher compressive strength. Maximum compressive strength can be obtained when the amount of magnesium slag replacing cement is 20%, where the 28-day compressive strength can be up to 45.48 MPa. This work provides a relatively comprehensive analysis of the structural characteristics and cementitious behavior of magnesium slag, which is conducive to the promotion of magnesium slag utilization.

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Development and field application of a modified magnesium slag-based mine filling cementitious material

Cited by 25 publications

References 74 publications

Field conditions for the synergistic increase of biomethane in the goaf of coal mines filled with corn straw

Field conditions for the synergistic increase of biomethane in the goaf of coal mines filled with corn straw

Effect of Thermal Activation on the Mineralogical Structure of Magnesium Slag

Structural Characteristics and Cementitious Behavior of Magnesium Slag in Comparison with Granulated Blast Furnace Slag

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