Dr Deside Chibwe
School of Engineering
Dr. Chibwe is a Research Associate in the Centre for Ironmaking Materials Research at the University of Newcastle. He completed his Bachelor of Science Honours degree in Metallurgical Engineering from the University of Zimbabwe, Harare, Zimbabwe followed by a Master of Science degree in Metallurgical Engineering from the University of Stellenbosch, Cape Town, South Africa and a Doctor of Philosophy degree in Chemical Engineering from the University of Newcastle, Newcastle, Australia.
Since the beginning of his career which kicked off in automotive and industrial battery manufacturing company, Smelting Process Department, he has worked in ferrous and non-ferrous pyro-metallurgical smelting operations in various capacities. Key interests and activities mainly involved the application of fundamental and applied research to solve, improve and address real-life process engineering problems related to mineral processing, bulk materials handling and pyro-metallurgy resulting in optimised utilisation of raw materials and process intensification. Initially, his research, which started in South Africa under the supervision of Professor Guven Akdogan at the University of Stellenbosch, mainly focused on computational fluid dynamics (CFD) investigations of submerged jets, mixing, mass transfer and phase distribution of high-temperature melt simulated at room temperature in lab scaled experimental rigs. The research involved a combination of experimental measurements and computational fluid dynamics (CFD) simulations. For the contributions made and in recognition of technical input to industrial solutions,
As a Research Associate in ARC Research Hub for Advanced Technologies for Australian Iron Ore which is focused on iron (ferrous) ore beneficiation, bulk materials handling and end-use functionality with major attention on developing innovative approaches on a suite of novel technologies to create enhanced value across the full value chain, Dr. Chibwe is currently reviewing the current blast furnace iron smelting practice and operation, particularly furthering the understanding of current process inefficiencies and interpret product requirements with more interest in the charging system and raw materials logistics, design and develop innovative solution concepts and flow sheets for the effective utilisation of ferrous burdens (sinter and lump iron ore) mixed with nut-coke that will improve the productivity of the iron blast furnace smelting process, improve pyro-metallurgical thermodynamics, mechanisms of chemical reactions and reduction of operational cost per tonne of hot metal (THM). He is carrying out proof of concepts and evaluation of the effectiveness of the new alternative mixed charging techniques with calibrated and validated discrete element modelling (DEM) numerical simulations.
- Doctor of Philosophy, University of Newcastle
- Bachelor of Science Engineering Honours, University of Zimbabwe
- Master of Science (Engineering), University of Stellenbosch - South Africa
- Computational fluid dynamics (CFD)
- Discrete element modelling (DEM)
- Mixing and mass transfer
- Multi-phase flow
- Particle dynamics
- English (Fluent)
Fields of Research
|091499||Resources Engineering and Extractive Metallurgy not elsewhere classified||30|
|091307||Numerical Modelling and Mechanical Characterisation||50|
|090499||Chemical Engineering not elsewhere classified||20|
|Title||Organisation / Department|
|Dates||Title||Organisation / Department|
|1/11/2011 - 30/12/2011||Commissioning Metallurgist||Lonmin Platinum Limited
|2/8/2004 - 29/4/2005||Process Engineer||Chloride Central Africa Limited
Lead Smelting Operations
|2/5/2005 - 31/12/2008||Process Engineer||Zimbabwe Iron and Steel Company
For publications that are currently unpublished or in-press, details are shown in italics.
Journal article (10 outputs)
Chibwe DK, Evans GM, Doroodchi E, Monaghan BJ, Pinson DJ, Chew SJ, 'Charge material distribution behaviour in blast furnace charging system', Powder Technology, 366 22-35 (2020)
© 2020 Elsevier B.V. Smooth operation, permeability control and high energy efficiency are critical operational indices which relate to the overall economic measure of the blast f... [more]
© 2020 Elsevier B.V. Smooth operation, permeability control and high energy efficiency are critical operational indices which relate to the overall economic measure of the blast furnace (BF) ironmaking process. The BF charging system is central to the realisation of good operational indices. However, the readiness of granular material to segregate (de-mix) due to particle geometry (size, shape, distribution and density) regardless of the material has been uniformly blended, remains a challenge. This research paper presents discrete element modelling (DEM) study to investigate, characterise and compare the effects of initial positioning of high flowability pellets material in ternary ferrous mixtures with two sinter material components of different sizes. In order to elucidate quantification of the particle-particle scale distributions of particle types relative to others as charge materials mix as well as providing useful inferences on segregation and dispersion, a quantitative approach using near-neighbour separation index (NNSI) was used to give instantaneous quantitative description of the material status in space and time during multiple handling state positions within the charging system. Based on the results obtained from the DEM simulations, the initial positioning of the high flowability pellets material in the upstream of the BF charging system has a bearing on the discharge flow characteristics in the downstream discharging operations as well as mixing and segregation behaviour of the material. The mobility of the high flowability pellets particles, compounded by their relatively small size, influence the overall material movement and interactions as they are acquiescent to percolation and sieving. The observations in this study form a significant contribution for considerations of a discharge model formulation for a mathematical model possible of tracking real-time material movements in a BF charging system.
Chibwe DK, Evans GM, Doroodchi E, Monaghan BJ, Pinson DJ, Chew SJ, 'Particle near-neighbour separation index for quantification of segregation of granular material', Powder Technology, 360 481-492 (2020) [C1]
Cloete JH, Akdogan G, Bradshaw SM, Chibwe DK, 'Physical and numerical modelling of a four-strand steelmaking tundish using flow analysis of different configurations', JOURNAL OF THE SOUTHERN AFRICAN INSTITUTE OF MINING AND METALLURGY, 115 355-362 (2015)
Chibwe DK, Akdogan G, Taskinen P, Eksteen JJ, 'Modelling of fluid flow phenomena in Peirce-Smith copper converters and analysis of combined blowing concept', JOURNAL OF THE SOUTHERN AFRICAN INSTITUTE OF MINING AND METALLURGY, 115 363-374 (2015)
Chibwe DK, Akdogan G, Bezuidenhout GA, Kapusta JPT, Bradshaw S, Eksteen JJ, 'Sonic injection into a PGM Peirce-Smith converter: CFD modelling and industrial trials', JOURNAL OF THE SOUTHERN AFRICAN INSTITUTE OF MINING AND METALLURGY, 115 349-354 (2015)
Chibwe DK, Akdogan G, Aldrich C, Taskinen P, 'Modelling of mixing, mass transfer and phase distribution in a Peirce-Smith converter model', CANADIAN METALLURGICAL QUARTERLY, 52 176-189 (2013)
Chibwe DK, Akdogan G, Taskinen P, 'Numerical investigation of combined top and lateral blowing in a peirce-smith converter', Chemical Product and Process Modeling, 8 119-127 (2013)
Typical current operation of lateral-blown Peirce-Smith converters (PSCs) has the common phenomenon of splashing and slopping due to air injection. The splashing and wave motion i... [more]
Typical current operation of lateral-blown Peirce-Smith converters (PSCs) has the common phenomenon of splashing and slopping due to air injection. The splashing and wave motion in these converters cause metal losses and potential production lost time due to intermittent cleaning of the converter mouth and thus reduced process throughput. Understanding of the effect of combined top and lateral blowing could possibly lead to alternative technology advancement for increased process efficiency. In this study, computational fluid dynamics (CFD) simulations of conventional common practice (lateral blowing) and combined (top and lateral blowing) in a PSC were carried out, and results of flow variables (bath velocity, turbulence kinetic energy, etc.) were compared. The two-dimensional (2-D) and threedimensional (3-D) simulations of the three-phase system (air-matte-slag) were executed utilizing a commercial CFD numerical software code, ANSYS FLUENT 14.0. These simulations were performed employing the volume of fluid and realizable k - e turbulence models to account for multiphase and turbulent nature of the flow, respectively. Upon completion of the simulations, the results of the models were analysed and compared by means of density contour plots, velocity vector plots, turbulent kinetic energy vector plots, average turbulent kinetic energy, turbulent intensity contour plots and average matte bulk velocity. It was found that both blowing configuration and slag layer thickness have significant effects on mixing propagation, wave formation and splashing in the PSC as the results showed wave formation and splashing significantly being reduced by employing combined top- and lateral-blowing configurations.
Chibwe DK, Akdogan G, Aldrich C, Taskinen P, 'Characterisation of phase distribution in a Peirce-Smith converter using water model experiments and numerical simulation', Transactions of the Institutions of Mining and Metallurgy, Section C: Mineral Processing and Extractive Metallurgy, 120 162-171 (2011)
In this study, we have experimentally and numerically studied fluid flow behaviour in industrial Peirce-Smith converter (PSC) using cold model simulations. The two- and three-dime... [more]
In this study, we have experimentally and numerically studied fluid flow behaviour in industrial Peirce-Smith converter (PSC) using cold model simulations. The two- and three-dimensional simulations of the three phase system were carried out using volume of fluid (VOF) and realisable k-e turbulence model to account for the multiphase and turbulence nature of the flow respectively. These models were implemented using commercial computational fluid dynamics (CFD) numerical code FLUENT. The cold model for physical simulations was a 1 : 5 horizontal cylindrical container made of Perspex with seven tuyeres on one side of the cylinder typifying a PSC. Compressed air was blown into the cylinder through the tuyeres simulating oxygen enriched air injection into PSC. Industrial treated feed, product and byproduct referred to as matte-white metal and slag were simulated with water and kerosene respectively in this study. The influence of blowing conditions on the distribution of phases was studied with five different compressed air volumetric flowrates at constant simulated matte and slag ratios. Both numerical and experimental simulations were able to predict the dispersion characteristics of the system in relation to flow and have substantially added to the understanding of the fluid dynamics of PSC. © 2011 Institute of Materials.
Chibwe DK, Akdogan G, Aldrich C, Eric RH, 'CFD modelling of global mixing parameters in a Peirce-Smith converter with comparison to physical modelling', International Journal of Green Economics, 6 (2011)
The flow pattern and mixing in an industrial Peirce-Smith converter (PSC) has been experimentally and numerically studied using cold model simulations. The effects of air volumetr... [more]
The flow pattern and mixing in an industrial Peirce-Smith converter (PSC) has been experimentally and numerically studied using cold model simulations. The effects of air volumetric flow rate and presence of overlaying slag phase on matte on the flow structure and mixing were investigated. The 2-D and 3-D simulations of the three phase system were carried out using volume of fluid (VOF) and realizable k - ? turbulence model to account for the multiphase and turbulence nature of the flow respectively. These models were implemented using commercial Computational Fluid Dynamics (CFD) numerical code FLUENT. The cold model for physical simulations was a 1:5 horizontal cylindrical container made of Perspex with seven tuyeres on one side of the cylinder typifying a Peirce-Smith converter. Compressed air was blown into the cylinder through the tuyeres, simulating air or oxygen enriched air injection into the PSC. The matte and slag phases were simulated with water and kerosene respectively in this study. The influence of varying blowing conditions and simulated slag quantities on the bulk mixing was studied with five different air volumetric flow rates and five levels of simulated slag thickness. Mixing time results were evaluated in terms of total specific mixing power and two mixing time correlations were proposed for estimating mixing times in the model of PSC for low slag and high slag volumes. Both numerical and experimental simulations were in good agreement to predict the variation characteristics of the system in relation to global flow field variables set up in the converter through mathematical calculation of relevant integrated quantities of turbulence, Volume Fraction (VF) and velocity magnitudes. The findings revealed that both air volumetric flow rate and presence of the overlaying slag layer have profound effects on the mixing efficiency of the converter.
Chibwe DK, Akdogan G, Eksteen J, 'Solid-liquid mass transfer in a Peirce-Smith converter: A physical modelling study', Metallurgical and Mining Industry, 3 202-210 (2011)
Pyro-metallurgical processes are multiphase in nature involving gas-liquid-solid interactions. In the Peirce-Smith converter operation, the additions of cold solids in liquid matt... [more]
Pyro-metallurgical processes are multiphase in nature involving gas-liquid-solid interactions. In the Peirce-Smith converter operation, the additions of cold solids in liquid matte in the form of fluxing agents (silica sands) for slag liquidity, process scrap and reverts for temperature control is a common practice. It is reasonable to postulate that with such practice, solid-liquid mass transfer step may play an important role in the performance and attainment of liquid bath homogeneity of the process. In this work, solid additions were simulated with sintered benzoic acid compacts spatially positioned in a 1:5 water model of a Peirce-Smith converter. Water and kerosene were used to simulate matte and slag respectively. Solid-liquid mass transfer was characterized by experimentally determined mass transfer coefficient, K (ms-1) values of benzoic acid sintered compacts and calculated dimensionless turbulence characteristic, Tc values. The mass transfer coefficients and dimensionless turbulence characteristic values were highest at the bath surface and near plume region. The values decreased in identified dead zones in the regions close to the circular side walls of the model. The results revealed that the mass transfer coefficients and turbulence characteristics were different with respect to different submergence levels of the compacts. These findings lead to the conclusion that the fluid flow was stratified within the vessel. © Metallurgical and Mining Industry, 2011.
|Show 7 more journal articles|
Conference (5 outputs)
Chibwe DK, Evans GM, Pinson DJ, Austin P, Biasutti M, Chew SJ, Monaghan BJ, 'Sinter - nut coke interaction and behaviour during conveyor belt transportation and discharge: A DEM study', Austria (2016)
|2014||Chibwe DK, Akdogan G, Bradshaw SM, Bezuidenhout GA, 'Physical and CFD modelling study of mixing and splashing phenomena in subsonic-sonic transition operated platinum group metals (PGMs) - Peirce-Smith converters', Mexico (2014)|
|2012||Chibwe DK, Akdogan G, Bradshaw SM, Bezuidenhout GA, Davis J, Eksteen JJ, Kapusta JPT, 'Towards sonic injection in Peirce-Smith converters: A computational fluid dynamics (CFD) modelling study', Canada (2012)|
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