Summer and Winter Research Programs for Undergraduates

The hydrocyclone performance testing

The devices most commonly used for classification in the mining industry are hydrocyclones. E Hydrocyclones have been preferred over most other devices due to low operating cost and a small footprint and have not received as much attention as more expensive comminution units, and their technological progress has been incremental.

This project is about the hydrocyclone performance testing.

The student will be helping with running the hydrocyclone test rig, collecting representative samples, sizing and data analysis. These steps are an important part in understanding how the hydrocyclone operating parameters can impact its performance.

This project is open to students willing to gain some experience in mineral classification.

Developing software for bubble size determination by using a convolutional neural network.

Froth flotation is one of the most common methods of recovering valuable minerals (metals) in the mining industry, and bubble size is one of the key drivers of flotation performance. Thus, proper control of bubble size is essential for maintaining good performance. Good control starts with good measurement. Bubble size is measured by taking snapshots of the bubbles and processing these images using image analysis software.

The aim of this project is to develop an advanced image analysis routine to determine size distributions of bubbles and bubble-particle aggregates from images taken inside operating froth flotation equipment.

These images will include existing ones collected during plant visits, as well as new ones collected during the laboratory and pilot plant experiments that will be conducted as part of this project. The experiments conducted during this project will be designed to compare different image capturing techniques and thus provide a wider range of example images to test the new image analysis routine.

The expected outcome of this project is a user-friendly image analysis routine capable of accurately determining bubble and particle sizes from images captured using a range of techniques. After the laboratory data collection and comparison of the different techniques, a journal article is an expected outcome of this project.

During this project, the student will have an opportunity to develop their laboratory, data-analysis, and report-writing skills. They will receive hands-on training in industry standard tools such as National Instruments LabVIEW, Mettler Toledo PVM, Mathworks MATLAB and python. And they will gain experience working to deadlines and specifications in a world-renowned industrially-focused research centre.

This project is open to applications from students with a software development background. Proficiency in programming languages such as MATLAB or python is essential for this project, and experience with image analysis and neural networks would be an advantage.

Applicants should be familiar with the health and safety requirements of laboratory work, and be comfortable conducting experiments with laboratory-scale equipment.

An experimental study of three-phase fluidisation behaviour in vessels of various designs

Fluidised bed reactors are used in fields such as oil and gas, biotechnology and pharmaceuticals for applications requiring a large surface area contact between a powder and a fluid (liquid or gas). Fluidised beds have recently been adopted in the field of mineral processing where they are used to increase the contact area between particles in a slurry (a mixture of solids and liquid) and air bubbles. Many questions remain about the behaviour of such three-phase fluidised beds.

The aim of this project is to experimentally study the behaviour of a fluidised bed of particles contained in vessels of various designs.

These experiments will include manual observations, the use of a specialist optical probe and a high-resolution camera, and online sensor measurements.

Once the data has been collected and analysed by the student, they will be asked to produce a final report. It is hoped that this report will form the basis of a journal publication, and that its findings will suggest further research questions.

In undertaking this project, the student will have an opportunity to develop their laboratory, data-analysis and report-writing skills. They will receive hands-on training in industry standard tools such as National Instruments LabVIEW, Mettler Toledo PVM and Mathworks MATLAB. And they will gain experience working to deadlines and specifications in a world-renowned industrially-focused research centre.

This project is open to students with a practical and numerate background, particularly in engineering. Applicants should be familiar with the health and safety requirements of laboratory work, and be comfortable conducting experiments with laboratory-scale equipment such as pumps and motors.

Processing the experimental data, particularly the image analysis, will require the use of a programming language such as Matlab or python. Training will be provided, but some familiarity would be beneficial.

A CFD study of a multi-phase fluidised bed

Fluidised bed reactors are used in fields such as oil and gas, biotechnology and pharmaceuticals for applications requiring a large surface area contact between a powder and a fluid (liquid or gas). Fluidised beds have recently been adopted in the field of mineral processing where they are used to increase the contact area between particles in a slurry (a mixture of solids and liquid) and air bubbles. Many questions remain about the behaviour of such three-phase fluidised beds.

The aim of this project is to conduct preliminary computational fluid dynamics (CFD) simulations of a small-scale fluidised bed containing a continuous liquid phase and two dispersed phases (particles and bubbles). The simulation results will be compared with experimental data to validate the computational approach.

Once the simulations have been performed, and the results analysed, the student will be asked to produce a final report. It is hoped that this report will form the basis of a journal publication, and that its findings will suggest further research questions.

In undertaking this project, the student will have an opportunity to develop their numerical modelling, data-analysis and report-writing skills. They will receive hands-on training in Siemens STAR-CCM+, an enterprise standard CFD code, in the use of UQ’s high-performance computing facility, and in MATLAB for scientific computing. And they will gain experience working to deadlines and specifications in a world-renowned industrially-focused research centre.

This project is open to applications from students with a numerate background, particularly in mathematics, physics and engineering. Basic programming experience is essential, although guidance in applying existing MATLAB code will be provided. Training in STAR-CCM+ will also be provided, but some experience of CFD or fluid mechanics would be a great advantage.

Assessment of the High Voltage Pulse Process for Ore Processing – Towards a Continuous System

BACKGROUND

Global demand for minerals and metals, particularly copper and gold, has risen and is forecast to continue rising in the decades to come. Indeed, Batterham (2017) quotes that demand in 2050 will be double that in 2015. The quality of deposits of these materials is decreasing, tending to be located at greater depths, hosted in harder rock matrices, be of lower grade and of a more complex, finer grained and disseminated mineralogy. As such, the costs of processing these deposits, to enable extraction of the valuable metals, have increased and will continue to do so unless novel technologies to reduce costs are developed and deployed.

Comminution is especially challenged in the face of likely future ores. Comminution is the process via which the individual minerals are made separable, typically due to the size reduction achieved. Comminution is currently the most energy intensive process used in minerals operations. This  will only increase for harder ores, with more disseminated, finer grained, complex mineralogies which will require finer grinding, and thus more energy input, to enable a subsequent separation to occur. High Voltage Pulse (HVP) technology is a selective comminution process designed to decrease the energy required to liberate valuable materials and enable their separation, such that the contained metals can then be extracted.

HVP comminution applies electrical energy directly to ore fragments to achieve selective breakage of particles containing metalliferous mineral grains. In the past 10 years, the JKMRC has conducted extensive research using HVP electrical comminution technology for the mineral industry and have become the leaders in this field. Three major applications for the mining industry have been identified and explored by the research team to date:

• Pre‐weakening – HVP generates cracks/microcracks which pre‐weaken ore particles for improved downstream comminution circuit energy efficiency or higher circuit throughput in a particular comminution design;
• Pre‐concentration – This selectivity allows for early gangue rejection as well as decreasing the economic cut‐off grade, by turning waste into ore;
• Enhanced Liberation – HPV results in preferential liberation of minerals resulting in improved recovery in the downstream separation processes. HVP can potentially enable alternative separation technologies, such as coarse particle flotation, to be viable.

Research to date has shown HVP has significant potential to address many current and future mineral processing challenges. Nonetheless, barriers remain to industrial uptake of the HVP technology.  Fundamental knowledge gaps, around ore composition and amenability to HVP, and the optimum means of incorporating this technology and the benefits it provides, into mineral processing circuits exist.

High Voltage Pulse Technology is a large and exciting research initiative at the JKMRC. The student will work with researchers and undertake various studies and tasks on HVP, including experimental and analysis of results, in order to obtain a better understanding of the responses of ores with different mineralogy to this novel technology.  The intern will gain valuable knowledge about the HVP process as well as learn technical and laboratory skills relevant to the mining industry.

PROJECT:

JKMRC has conducted extensive research using high voltage pulse (HVP) electrical comminution technology for the mineral industry. Three major potential applications using the HVP technology have been reported:

• Cracks/microcracks generation to pre-weaken ore particles for improved comminution circuit energy efficiency (Wang, Shi and Manlapig, 2011; Shi et al., 2014);

• Preferential liberation of minerals which could potentially enable recovery at coarser sizes in the separation processes (Wang, Shi and Manlapig, 2012; Parker et al., 2015).

• Selective fragmentation of particles containing high conductivity/permittivity minerals followed by size-based separation for ore pre-concentration (Zuo, Shi and Manlapig, 2015; Shi, Zuo and Manlapig, 2015). This technology has the potential to upgrade ore by rejecting waste material prior to processing. Alternatively, it can split an ore into different grade components which can be sent to different recovery processes.

The HVP technology therefore has the potential to be applied to improve ore processability of different mineralised ore.  Most of the research done to date has used a commercial HVP unit in batch mode.  The JKMRC has installed a Flexible HVP Testing Facility and has recently designed and commissioned a small-scale continuous HVP system.  The objective of this project is to optimise the new processing unit and to investigate different parameters (i.e. electrode configuration, operating settings, operating mode, etc.) to assess its efficiency with respects to ore breakage and pre-concentration.

The successful applicant will be working with researchers and a PhD Student on this project.  It is envisaged that the applicant will gain both experimental and data analysis skills from the work to be undertaken.  The successful applicant will obtain:

• Exposure to the mining industry
• Training on a variety of sample preparation equipment and analysis tools
• Experience in the novel HVP technology which could lead to potential step-change in industry
• Experience in experimental work and investigating the performance of HVP on a particular ore type
• Data collection and analysis skills

At the completion of the project, the successful applicant will be asked to produce a report and/or an oral presentation of their project. They will also have an opportunity to generate publications from their research work.

This project is suitable for 3rd – 4th year students only with a background in mining, minerals processing or chemical engineering.

Hybrid Microwave Technology for Dry Stacked Tailings Applications

BACKGROUND

One of the most pressing challenges facing the mining industry today is the increasing frequency of catastrophic tailings dam collapses. Such events are known to cause significant environmental damage as well as loss of life. A viable alternative to tailings storage in dams is Dry Stacking of Tailings.

One of the major obstacles to implementing Dry Stack Tailings is that it requires a maximum moisture content of 10 – 12 wt%. Coal tailings material contain significant amounts of moisture, requiring removal prior to disposal. A host of conventional technologies are currently employed to dewater tailings however, products from these processes may still contain up to 40% moisture.

Microwave dewatering is an alternative technology that has the potential to achieve the required moisture content of tailings to both satisfy material handling requirements and achieve a product that is dry enough for stacking. Microwave systems can be mounted above a rapidly moving conveyor, continuously removing moisture.  Microwaves also have the potential to be more energy efficient than conventional heating because it selectively heats the water in the tailings, rather than heating the solids.

The use of microwaves is widely understood to be highly effective in dewatering. Microwave technology has the potential to reduce the moisture content of mineral slurries suitable for dry stacking. However, this comes at a considerable energy cost. For this reason, microwaves have not been accepted in the minerals industry despite their efficacy.

This project proposes a new approach to developing a technology that can reduce the tailings moisture content to the level required for dry stacking, at a reduced operational and capital cost – the use of Hybrid Microwave Technology. Two different approaches are being investigated:

1. Microwave Polishing – a hybrid system consisting of both a conventional dewatering technology and microwave technology
2. Selective Processing – a hybrid system which requires separate processing paths for coarse and fine tailings.

These methods could bridge the moisture content gap between conventionally dewatered material and Dry Stack Tailing requirements.

This project will be undertaken at JKMRC and will comprise benchmarking experiments using microwave energy and assessing conventional technology including heating, filtration and centrifuging, to allow comparison with microwave technology. It is expected that the outcomes from this work will include a better understanding of the characteristics of different tailings samples and their amenability to microwave treatment. The information collected can then be used to develop the concept for a microwave-assisted dewatering system.

The successful applicant will be part of a larger project working towards developing a hybrid microwave technology to achieve tailings suitable for dry-stacking.  The successful applicant will work with JKMRC researchers on this project.  It is envisaged that the applicant will gain both experimental and data analysis skills from the work to be undertaken.  The successful applicant will obtain:

General:

• Introduction to the mining industry
• Training on a variety of sample preparation equipment and analysis tools used in the mining industry
• Experience in simulation software
• Data collection and analysis skills

Project Specific:

• Exposure to the mining industry and the challenges in tailings management
• Training and experience in novel microwave technology and other dewatering equipment
• A better understanding of the characteristics of different types of tailings samples and their amenability to microwave treatment

At the completion of the project, the successful applicant will be asked to produce a report and/or an oral presentation of their project. They will also have an opportunity to generate publications from their research work.

This project is suitable for 3rd – 4th year students only, with a background in mining, minerals processing or chemical engineering.

Primary breakage and its effects on mineral and liberation distribution

This research project will support an existing PhD project that is researching on how to integrate teeter bed floatation technologies into comminution circuits aiming for early coarse waste rejection.

Coarse waste rejection is a processing strategy that aims to save grinding energy and increase circuit capacity by separating gangue particles as early as possible in the flowsheet to avoid grinding the entire ore stream to the final required size. Integrating these technologies into comminution circuits poses new technical questions due to its requirement of a coarse, narrowly sized feed distribution. Its performance will also be governed by the degree of liberation of the feed to the flotation device. To optimise the effectiveness of coarse gangue rejection using teeter bed flotation, there is a need to better understand how mineral deportment and liberation is affected by comminution and classification processes.

This project will try to decouple the effects of breakage and classification within a breakage device, to be able to measure how liberation classes respond to a single primary breakage event.

The student will receive training in the safe use of the breakage devices to conduct experimental investigations, as well as gain skills in accurate data collection, analysis and reporting. The student will be integrated into the research program of the JKMRC and receive instruction on minerals processing knowledge and common breakage characterisation techniques in mining industry.

This project is suitable for students who would like to learn basic mineral processing skills and theories.

Self-motivation and willingness to learn new skills are essential.

Experimental work using the Short Impact Load Cell breakage device to assist comminution

The Julius Kruttschnitt Minerals Research Centre (JKMRC) is world-renowned for development of novel rock breakage characterisation devices for the mining industry.

Short impact load cell (SILC) is a research device being used to characterise rock breakage when particles are broken under impact. This device is part of a generation of instrumented breakage test for improving practices in mining industry, which aims to improve understand of breakage using less material and faster tests.

The objective of this project is to assess whether the results of cumulative distribution from SILC tests can be better interpreted if related to the particles physical characteristics. For instance, if more energy is related to breakage spherical particles rather than more flaked or elongated ones while still fitting to similar size range. The student will also contribute to increasing our database of breakage using SILC.

This research requires a student to conduct a series of breakage experiments for different particle size and shape. The experimental plan includes sample preparation, measurement of the dimensions of the particles, sorting by shape or volume, execution of the experiments and the analysis of the results.

The successful applicant will receive training in the safe use of the breakage device to conduct experimental investigations. Strong attention to detail is required. Processing the experimental data will require the use of a programming language such as Matlab or python, some familiarity would be beneficial.

The applicant will receive knowledge on minerals processing and breakage characterisation techniques for comminution. This project can be the start of a larger research project, such as Honours or PhD.

The project is well suited to engineering and/or geologist students with an interest in rock characterisation and breakage. Ideal candidates would be 3rd - 4th year or Masters Earth Sciences, or Engineering students.

A novel method to gathering data for ore breakage modelling

The student will work with a PhD student to gather data to populate the primary breakage appearance function. A novel rolls breakage device will be used to precisely measure the energy to fragment a range of mineral ores. The progeny of the breakage will then be fitted to generic models to describe the breakage function.

The stage of comminution (reducing mined rocks to fine powders for mineral extraction), uses over 1/3 of all mining energy and the equipment is generally the production bottleneck on mines. A novel device for rapidly breaking many particles (as small as 0.2 mm) is under development for accurately characterising the breakage energy requirements for existing and new ore bodies.

This project will gather data from the accurate rolls breakage device and work with Dr Weatherley on applying the product size to a model of breakage that can then be applied to modelling production comminution devices.

This is an experimental project with careful data analysis, followed by assessing models of the results.

The student will develop a range of skills in conducting experiments, the experimental method, and data analysis.

Generic skills in conducting laboratory-based experiments, scientific methods, data integrity etc. will be developed. This will include utilising and potentially coding automated data logging software, data cleaning, and review.

Clear and comprehensive reporting of the experimental outcomes through progress updates and data presentation is expected over the duration of the project. A simple oral presentation and summary report will form the fila delivery.

This project also provides the student with exposure to research in the mineral processing arena that can open up final year Project and further study opportunities.

We encourage technically skilled students who have an interest in research. Some experience in mathematical modelling and coding is an asset but not essential.

Transport of media along a mill

The student will work conducting experiments in the JKMRC pilot plant, on a modified small tumbling mill. The objective is to measure the rate at which rocks are transported along the mill as a function of rock size.

The stage of comminution, reducing mined rocks to fine powders for mineral extraction) uses over 1/3 of all mining energy and the tumbling milling equipment commonly used is generally the production bottleneck on mines.

The JKRMC has progressively developed models of these mills over the past 50 years, with the next iteration being a step-change to mechanistic models, to greatly improve the fidelity and predictive capability relative to the current suite of models. The transport of material along these mills (that are up to 12m long) is poorly understood and lacking form all but the most recent models that are under development.

The project will use a scaled model of a production mill (about 1m long by 0.5m diameter) to conduct controlled experiments of the factors that influence transport and segregation of rocks in these mills. These findings will feed directly into the mechanistic mill models.

This is an experimental project with careful data analysis and interpretation.

The student will develop a range of skills in conducting experiments, the experimental method, and data analysis.

Generic skills in conducting larger laboratory-based experiments, scientific methods, data integrity etc. will be developed. This will include utilising and potentially coding automated data logging software, data cleaning, and review.

Clear and comprehensive reporting of the experimental outcomes through progress updates and data presentation is expected over the duration of the project. A simple oral presentation and summary report will form the fila delivery.

This project also provides the student with exposure to research in the mineral processing arena that can open up final year Project and further study opportunities.

We encourage technically skilled students who have an interest in research and enjoy experimental work.

Investigating SAG mill operational behaviour

Ball mill overloading is a phenomenon that can impede the optimal operation of the comminution circuit. The development of methods to detect the onset of ball mill overloading is not yet mature. This project will explore the effect of void filling and feed particle distribution (F80) and lifter profile on ball mill performance. Performance indicators used to understand the onset of overloading are mill power draw and product size distribution.

The student will be helping with preparing the feed to the SAG mill, running the mill, collecting representative samples, sizing and data analysis. These are crucial steps for understanding the operational behaviour of the SAG mill.

This project is open to students willing to gain some experience in mineral classification.