Discrete element modeling of particle breakage considering different fragment replacement modes

Zhou, Wei; Wang, Di; Ma, Gang; Cao, Xuexin; Hu, Chao; Wu, Wei

doi:10.1016/j.powtec.2019.10.002

Cited by 62 publications

(37 citation statements)

References 63 publications

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“…As already reported by Schönert [14] and recently observed by Zhou et al [38] using DEM simulations, the main cause for the drop in energy efficiency in particle bed breakage is the reduction in the voids that are caused by fine debris relocating themselves as a result of the application of high normal applied stresses. Such a drop in energy efficiency in compressed bed breakage is also evident in Figure 9 for specific energies higher than about 6 kWh/t.…”

Section: Blaine Specific Surface Areamentioning

confidence: 51%

“…Assessing limestone breakage response under confined conditions, Cabiscol et al [29] observed that the packing density reached a maximum of around 90% of the specific gravity of the material with particles with mean initial size of 236 µm, being equivalent to the value found by Wünsch et al [28] for different materials used in the production of pharmaceutics. On the other hand, recent works have attempted to assess particle bed behavior under confined conditions from computational simulations using the discrete element method (DEM) [37][38][39]. Besides DEM simulations, Garner et al [37] also showed several experimental results highlighting the ability to reach relative densities around 0.95 for a vertical stress of 150 MPa.…”

Section: Introductionmentioning

confidence: 99%

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Confined Bed Breakage of Fine Iron Ore Concentrates

2020

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High-pressure grinding rolls (HPGR) have gained great popularity in the mining industry in the last 25 years or so. One of the first successful applications of the technology has been in iron ore pressing prior to pelletization. Piston-and-die tests can provide good insights on the material response in an HPGR. This work analyzed confined bed breakage of four iron ore concentrates under different conditions. Saturation in breakage of particles contained in the top size in the tests was observed to occur at specific energies of about 2 kWh/t, whereas full saturation in breakage, with no additional increase in specific surface area of the material, occurred at energies above about 6 kWh/t. An expression was proposed to characterize the propensity of a material to break under confined bed conditions. The phenomenology involved in confined bed breakage of such materials was then analyzed in light of the results.

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Section: Blaine Specific Surface Areamentioning

confidence: 51%

Section: Introductionmentioning

confidence: 99%

Confined Bed Breakage of Fine Iron Ore Concentrates

2020

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Section: Discussionmentioning

confidence: 99%

“…The formation of new cohesive bonds during the simulation would allow us in the future to reproduce the ductile-to-brittle transition in snow and thus the repetitive formation and reflection of compaction bands, as observed by Barraclough et al 2 . Additionally, www.nature.com/scientificreports/ implementing a particle breakage criterion 41,42 would enable us to simulate more complex types of localized deformation such as erratic and oscillatory compaction bands, observed in the compression of rice crispies 1 . Evaluating the conditions for the onset of localization of compacting shear bands or anticrack nucleation in porous rocks is a great challenge 5,43 and has implication for the understanding of deep earthquakes.…”

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confidence: 99%

Microstructural controls of anticrack nucleation in highly porous brittle solids

Ritter

Löwe²,

Gaume

2020

Sci Rep

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porous brittle solids have the ability to collapse and fail even under compressive stresses. in fracture mechanics, this singular behavior, often referred to as anticrack, demands for appropriate continuum models to predict the catastrophic failure. to identify universal controls of anticracks, we link the microstructure of a porous solid with its yield surface at the onset of plastic flow. We utilize an assembly method for porous structures, which allows to independently vary microstructural properties (density and coordination number) and perform discrete element simulations under mixed-mode (shear-compression) loading. In rescaled stress coordinates, the concurrent influence of the microstructural properties can be cast into a universal, ellipsoidal form of the yield surface that reveals an associative plastic flow rule, as a common feature of these materials. Our results constitute a constructive approach for continuum modeling of anticrack nucleation and propagation in highly porous brittle, engineering and geo-materials.

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“…With this approach, from one hand we control our computational cost but also represent particle characteristics as close as possible to laboratory experiments. Our DEM model is developed based on the open source software LIGGGHTS (Kloss et al 2012) as discussed extensively in our previous works (Dorostkar et al, 2017a(Dorostkar et al, , 2017bDorostkar andCarmeliet, 2018, 2019;Ren et al, 2019;Zhou et al, 2020). -b show the time series of macroscopic friction and thickness of granular gouge comparing the unbreakable (reference run with no fragmentation model) and breakable samples with = 40 MPa.…”

Section: -Methodsmentioning

confidence: 99%

On the Effect of Grain Fragmentation on Frictional Instabilities in Faults With Granular Gouge

et al. 2021

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The evolution of frictional strength during stick-slip dynamics of a fault system is key to understanding the earthquake nucleation and rupture patterns. In mature faults, granular gouge is produced by wear, comminution or fragmentation during tectonic movements. In this work, we introduce a fragmentation model in the simulation of a sheared granular fault to explore the influence of grain breakage on the stick-slip dynamics. With fragmentation of highly stressed particles, the fault frictional strength increases accompanied with many small slip events triggered by particle breakage. The small fragments produced by particle breakage are not only stronger and more difficult to break, but they also change the distribution of contact forces, leading to strengthening of the fault system. By statistical analyses on size distribution of slip events under different particle strengths, we find that when particles are weaker, slip events become more correlated with particle fragmentation events and that the number of large slip events decreases. In addition, our analyses on the relationship between slip and particle fragmentation events reveal three types of correlations: in the first and second types, particle fragmentation events trigger micro-or major slips, respectively. In the third category, large-scale particle fragmentations take place at the end of large slip events owing to stress localization during post-slip particle rearrangements. Our results in this work highlight the role of micromechanics of particle fragmentation in failure of fault damage zones and help in understanding the relation between particle breakage and frictional failures.

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Discrete element modeling of particle breakage considering different fragment replacement modes

Cited by 62 publications

References 63 publications

Confined Bed Breakage of Fine Iron Ore Concentrates

Confined Bed Breakage of Fine Iron Ore Concentrates

Microstructural controls of anticrack nucleation in highly porous brittle solids

On the Effect of Grain Fragmentation on Frictional Instabilities in Faults With Granular Gouge

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