Predicting the effect of operating and design variables on breakage rates using the mechanistic ball mill model

By means of Discrete-Element simulations with Bonded-Cell method for particle breakage, we investigate the evolution of crushable granular materials in a 2D rotating drum partially filled with heavy balls and powder grains. The grinding process with balls of different sizes or numbers is analyzed in terms of grain size and specific surface. The grinding rate is an increasing function of the number of balls, but, as a result of increasing energy dissipation by inelastic collisions between the balls, the process becomes energetically less efficient for larger number of balls. When the total volume of balls is kept constant, the ball size has generally little influence on particle breakage. We also introduce a model for the evolution of three size classes by accounting for the cushioning effect and transition rates between the classes. This model predicts an exponential decrease of the volume of large particles at the beginning of the process.

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“…In contrast, with large ball size D b (D b /D p = 10), fewer impacts of higher magnitude occur [42]. As shown in Fig.…”

Section: Effect Of Ball Sizementioning

confidence: 90%

Discrete-element simulations of comminution in rotating drums: Effects of grinding media

et al. 2020

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“…Furthermore, several studies investigated the effect of the variation of kinetic model parameters, when different mill operating conditions were used. These conditions include ball size [33][34][35][36], media shape [37,38], mill speed [28,39] and powder loading [40].…”

Section: Introductionmentioning

confidence: 99%

Improved Modeling of the Grinding Process through the Combined Use of Matrix and Population Balance Models

Petrakis

Komnitsas

2017

Minerals

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Abstract:The mechanistic approach has proven so far to be flexible and successful for simulation of the grinding process. The basic idea underlying mechanistic models, namely the matrix and population balance models, is based on the identification of natural events during grinding. Since each model has its own capabilities and limitations, their combined use may offer additional advantages on this aspect. In this study, the matrix model and the selection function, namely the probability of breakage of the population balance model, were combined through a MATLAB code to predict the size distribution of the grinding products of quartz, marble, quartzite and metasandstone. The modeling results were in very good agreement with the particle size distributions obtained after grinding the feeds in a ball mill.

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“…O comportamento das partículas que apresentam características diferentes, tais como: tamanho, forma e estrutura interna; já foi estudada por diversos autores como King (2001), Austin (1994), entre outros Carvalho (2013). Segundo Tavares (1997), existe uma variabilidade intrínseca relacionada à fratura em populações de partículas, ou seja, em partículas do mesmo material, com mesma faixa granulométrica é possível encontrar uma grande variabilidade de partículas com diferentes resistências, sendo algumas mais fáceis de fratura que outras.…”

Section: Figura 2: Princípios De Fragmentação Das Partículas De Coqueunclassified

Avaliação Da Resistência Mecânica a Compressão No Coque

Oliveira¹,

Silva²,

Moura³

et al. 2017

Anais Do Congresso Anual Da ABM

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Resumo O coque desempenha três principais funções no Alto-Forno sendo elas: física, térmica e química, em se tratando do papel físico, a função estrutural é de primordial importância, pois não pode ser assumida por outro combustível, com isto as indústrias avaliam a resistência mecânica a frio para garantir uma marcha estável no reator, porém os ensaios padronizados não são suficientes para avaliar a resistência do coque. Neste contexto este trabalho desenvolveu uma metodologia para avaliar de forma individual a resistência mecânica a compressão do coque nas granulometrias típicas do coque metalúrgico e como os principais defeitos, poros e trincas governam a resistência do material. Foram realizados testes de compressão, análise de microestrutura, microtextura, inspeção visual de trincas, MEV. Os resultados das análises realizadas no coque mostraram que a tensão média de ruptura aumenta com o aumento da granulometria.

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Predicting the effect of operating and design variables on breakage rates using the mechanistic ball mill model

Cited by 92 publications

References 13 publications

Discrete-element simulations of comminution in rotating drums: Effects of grinding media

Discrete-element simulations of comminution in rotating drums: Effects of grinding media

Improved Modeling of the Grinding Process through the Combined Use of Matrix and Population Balance Models

Avaliação Da Resistência Mecânica a Compressão No Coque

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