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Single particle breakage tests have been used by a number of researchers to investigate some salient features of the complex comminution process. A twin pendulum setup is designed to indirectly measure the losses in energy for single particle breakage which is assumed to be equivalent to comminution energy. Calculated comminution energies are analyzed for their relations against breakage characteristics therefore impact energies, specimen size and operating work index. Breakage pattern of material also analyzed with the determination of single distribution parameter (t 10). Comminution energies and breakage behavior both analyzed against the transfer patterns of energy; transfer of part of impact energy to useful energy in comminution and its dependency on breakage characteristics such as material hardness and size of material are presented and discussed in this article. Above mentioned terms are modeled to bring conclusions in a mathematical platform.

Continuous fluidized bed roasters are being widely used in industries for oxidation of sulphide ores. In the present study we consider a roaster of height 24.5m, freeboard diameter of 16.85m and bed diameter of 12.5m. The distributor contains 12300 nozzles of diameter 6mm. It has two material inlets for the zinc concentrate, one gas outlet for the top product and one outlet for the bottom product. The air is blown from the bottom through four inlets for distribution across the distributor. Cooling of the bed is done by ten cooling coils inserted in the bed and water injected on the top of the bed. The feed contains around 60% particles of size ��� 57 micron. The initial bed height is 0.8m. In this study a 3D multiphase Eulerian-Eulerian computational fluid dynamics model has been used to study the flow profile of the particles of different sizes individually (two-phase flow) as well as together (five phases). Due to the complexity of the geometry, the roaster was divided into several zones to reduce the number of cells and the computational time. Single phase simulations were carried out with 2.4 million, 3.2 million as well as 4.3 million cells and it was found that for preliminary studies a computational domain consisting of 2.4 million cells would suffice. Simulations were carried out on a HPC with 32 nodes. It was seen that there was considerable difference in the flow profiles in the case of two-phase and five-phase flow for finer particles due to resistance offered by larger size particles on the flow of finer particles.

Continuous fluidized bed roasters are being widely used in industries for oxidation of sulphide ores. In the present study we consider a roaster of height 24.5m, freeboard diameter of 16.85m and bed diameter of 12.5m. The distributor contains 12300 nozzles of diameter 6mm. It has two material inlets for the zinc concentrate, one gas outlet for the top product and one outlet for the bottom product. The air is blown from the bottom through four inlets for distribution across the distributor. Cooling of the bed is done by ten cooling coils inserted in the bed and water injected on the top of the bed. The feed contains around 60% particles of size ��� 57 micron. The initial bed height is 0.8m. In this study a 3D multiphase Eulerian-Eulerian computational fluid dynamics model has been used to study the flow profile of the particles of different sizes individually (two-phase flow) as well as together (five phases). Due to the complexity of the geometry, the roaster was divided into several zones to reduce the number of cells and the computational time. Single phase simulations were carried out with 2.4 million, 3.2 million as well as 4.3 million cells and it was found that for preliminary studies a computational domain consisting of 2.4 million cells would suffice. Simulations were carried out on a HPC with 32 nodes. It was seen that there was considerable difference in the flow profiles in the case of two-phase and five-phase flow for finer particles due to resistance offered by larger size particles on the flow of finer particles.

A drop weight tester (DWT) is designed and fabricated for the purpose of analyzing single particle impact breakage characteristics of different ores. The test results were evaluated through the breakage distributions of different size fractions at five different input energy levels. The breakage parameter, t10 (Narayanan, 1986) is used to represent the degree of size reduction, which is assumed to be representative of the breakage product size distribution obtained from single particle breakage. Representation of breakage distribution with this method consist one more breakage dependent parameter (��). To evaluate the impact breakage characteristic of different ores, a mathematical relationship was established to analyze the dependency of breakage parameters, t10 and �� on specific input energy (EIS) or fracture energy (Tavares et al, 1998, Fandrich, 1998), specimen size (��) and Bond���s operating work index (WI0). Mathematical results developed gives adequate model for all ball mill modeling. It can be concluded that the drop weight test method is a useful and practical way of evaluating the impact strengths of various ores and results of which can be used in modeling mills.