PhD Opportunity - Numerical modelling of the iron ore sintering process
Thursday, 17 August 2017
A PhD Scholarship is available through the Faculty of Engineering and Built Environment at the University of Newcastle for a student to investigate Numerical modelling of the iron ore sintering process under the supervision of Professor Geoff Evans, and Associate Professor Tom Honeyands.
Iron ore sinter constitutes up to 70-85% of the total ferrous burden in the blast furnace process, which remains the major source of iron production worldwide (1.2 billion tonnes in 2016).
The sintering process is utilised to convert weakly-bonded iron ore granules into a partially fused porous sinter cake using coke breeze as fuel.
In a typical sinter strand, air is drawn down and a flame front is allowed to propagate at 1200-1400oC through the granule bed.
The process results in partially melted bed which solidifies into a bonding phase for the unreacted materials upon cooling.
Partial phase transformations, i.e., melt formation and coalescence of particles and release of gaseous products during the sintering process, lead to a porous structure. Interspersed between the large voids are the densified lumps of sinter which are released on crushing and used as blast furnace feed.
When less densified, weaker sinters are formed due to lower level of coalescence.
Each solid phase has a different particle size and chemical composition.
BHP in association with University of Newcastle has developed a detailed iron ore modelling framework which uses a proprietary material database to predict a number of parameters such as particle size distribution after granulation, green bed permeability, bed temperature profile, waste gas composition, and sintering air velocity.
The proposed PhD project aims to numerically investigate this complex multiphase system and suggest improvement to this existing model.
Emphasis will be given to quantify permeability in different zones of the bed i.e. green (un-sintered) zone, flame front zone accounting for transformation of the solid phase into the melt (liquid) and re-solidification into sintered clusters, and the sintered cake zone.
Particle size changes during the combustion process which affect bed porosity hence bed structure, with additional complexity due to the formation of a liquid melt.
This project will aim at developing a mechanistic description of spatial variation in bed porosity in the direction of flame front propagation and estimate sintering air flow rate using a better physical representation of flame front resistance which is often derived empirically.
It is necessary to obtain a thorough understanding the hot gas flow through the sintering bed involving gas to solid phase heat transfer, corresponding phase transformation and re-generation of the pore structure as the flame front gradually descends from top to bottom of the bed.
Outcome of the physical knowledge of the process translates directly into the quality of the finished sintered material (agglomeration/coalescence level) that finally needs to be fed to the blast furnace.
The improved sinter model will also aim to include better estimation of fuel rate and prediction of sinter product quality parameters. It will be used to better understand how to optimise the sintering of changing iron ore blends in the industry (including more goethitic ores and finer ores).
For the validation of the developed model, some experiments will be necessary which may be carried out at the University of Newcastle itself or one of its collaborating partners.
During the project, the candidate will have the opportunity to liaise with our industrial partner BHP (the world’s largest diversified resources company), relevant industrial and academic researchers and he/she will have the prospect of travelling nationally/internationally for conference presentations.
The studentship is for a period of three years, subject to satisfactory progress and provides payment of tuition fees plus an annual stipend of $26,682 plus a supplement if applicable.
Honours degree in chemical, mechanical, or materials/metallurgical engineering with strong computational background. Experience in multiphase system modelling using CFD tools, programming language (FORTRAN, C), MATLAB and Microsoft Excel Macro coding is desirable.
Applicants are advised to contact Tom Honeyands.
Contact: Tom Honeyands
Ph: +61 2 4033 9216