In this study, the behaviour of iron ore fines with varying levels of adhesion was investigated using a confined compression test and a uniaxial test. The uniaxial test was conducted using the semi-automated uniaxial EPT tester in which the cohesive strength of a bulk solid is evaluated from an unconfined compression test following a period of consolidation to a pre-defined vertical stress. The iron ore fines were also tested by measuring both the vertical and circumferential strains on the cylindrical container walls under vertical loading in a separate confined compression tester - the K-0 tester, to determine the lateral pressure ratio.
Discrete Element Method simulations of both experiments were carried out and the predictions were compared with the experimental observations. A recently developed DEM contact model for cohesive solids, an Elasto-Plastic Adhesive model, was used. This particle contact model uses hysteretic non-linear loading and unloading paths and an adhesion parameter which is a function of the maximum contact overlap. The model parameters for the simulations are phenomenologically based to reproduce the key bulk characteristics exhibited by the solid.
The simulation results show a good agreement in capturing the stress history dependent behaviour depicted by the flow function of the cohesive iron ore fines while also providing a reasonably good match for the lateral pressure ratio observed during the confined compression K-0 tests. This demonstrates the potential for the DEM model to be used in the simulation of bulk handling applications.
|Title of host publication||PARTICLE-BASED METHODS III: FUNDAMENTALS AND APPLICATIONS|
|Editors||M Bischoff, E Ramm, E Onate, R Owen, P Wriggers|
|Place of Publication||08034 BARCELONA|
|Publisher||INT CENTER NUMERICAL METHODS ENGINEERING|
|Number of pages||12|
|Publication status||Published - 2013|
|Event||3rd International Conference on Particle-based Methods - Stuttgart, Germany|
Duration: 18 Sep 2013 → 20 Sep 2013
|Conference||3rd International Conference on Particle-based Methods|
|Period||18/09/13 → 20/09/13|
- Granular materials
- discrete element method
- flow function
- uniaxial test
- iron ore fines
- cohesive solid