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Flotation Performance Improvement by Air Recovery Optimisation on Roughers and Scavengers

Sep 13, 2010

The role of government and the community has changed significantly over the last two decades in relation to environment protection, particularly in the mining sector. Increased community expectations have moved well ahead of regulatory requirements, and there is now a much greater appreciation generally of the concepts of ecologically sustainable development and intergenerational equity, and the gap between current practice and practices which would be in harmony with these concepts. Besides providing a `safety net' through regulations to ensure that basic environmental performance standards are met, government is now working proactively with the mining industry to encourage higher levels of environmental performance. This paper describes some initiatives between the Commonwealth government and the industry designed to achieve these higher levels of environmental performance, through programs aimed at the paradigms of best practice environmental management and continual improvement.

Jan 1, 1997

Truck fires in a tunnel can create heat release rates (HRR) significantly higher than 100 MW. Because of a fast spread of smoke and heat the self-rescuing period is shortened significantly. Furthermore, it was experienced that firefighters are not able to approach the fire because of enormous heat and radiation. As consequence, the fire may spread to adjacent vehicles, which is reported for distances of more than 50 m. Tunnels can be damaged severely by fires and the repair works causes long closing time of tunnels. In addition to direct costs for the refurbishment of the tunnel, further economic losses will occur due to the closure time. Conventional deluge systems in Japanese and Australian road tunnels have been known since the 1960s. During the last years the research work was concentrated in the development of more effective and cost-effective solutions based on water mist technology. Orientating fire tests as well as specifications of minimum requirements were carried out within the European research project UPTUN. This basic work was extended by the safety of life in tunnels (SOLIT) research project, funded by the German government. The scope of SOLIT was not only to study the effects of water mist fire suppression systems in tunnels, but also the interactions with other safety systems, such as fire detection, passive fire protection or ventilation. Furthermore, the integration of active fire suppression systems into a holistic tunnel safety system was part of the work program. Within this research project a large-scale fire test program with more than 50 fire tests, including 25 truck fires with a potential HRR of almost 200 MW, was carried out in the test tunnel of San Pedro des Anes (Spain). Furthermore, a two-week testing and training period with the Madrid Fire Brigade was carried out after the SOLIT program. Two fundamental results were achieved during the fire tests:Primarily, water mist systems are able to control the HRR of fires in tunnels, so the atmosphere will be improved significantly. Hazardous effects of toxic smoke on people will be reduced and due to the reduction of temperatures and radiation, a firefighterÆs approach is improved significantly. Furthermore, the fire spread will be hampered and the thermal load on the building structure also be reduced. Secondarily, due to positive interactions with the ventilation system, the effectiveness of a tunnel ventilation system, longitudinal as well as semi-transversal, is increased significantly. Based on the results of the SOLIT research project, a water mist system was applied into several parts of the M30 tunnels in Madrid. As a basic principle the technical equipment and the methodology of implementation comply with the UPTUN 251 guidance, recommending minimum standards for water-based fire suppression systems in tunnels.

Jan 1, 2008

The mining industry continues to faces significant challenges due to increasing resource constraints (quality of ore bodies, water, energy, human resources) and increasing license to operate requirements (safety, health, environment, location) from society, employees and shareholders. Technology advancements and hence research are necessary to ensure that the industry remains viable in this changing environment. Collaborative research is an important part of a company's research portfolio and offers the opportunity for the industry to work on generic issues that it is facing. Obvious benefits include the reduced cost to individual companies by sharing the costs, the opportunity to leverage government funding and the opportunity to conduct longer term projects resulting in skills development (PhD and MSc). Limitations of collaborative research include the reduced focus on company specific issues and the loss of competitive advantage from owning the outcomes of the research. The challenge for researchers and research managers is for them to demonstrate the value derived from longer term, pre-competitive collaborative research. The competitive advantage is not necessarily derived only from the outcomes of the research but rather from the company's ability to direct the research, translate the generic research outcomes to address company specific issues and to implement improvements at its operations. Implementation remains the greatest challenge. In this paper, case studies of selected collaborative research projects are presented to demonstrate key success factors required for implementation of research outcomes. This is an ABSTRACT ONLY. A full-length paper was not prepared for this presentation.

Sep 13, 2010

Efficiency, Economics, Energy and Emissions - Emerging Criteria for Comminution Circuit Decision Making

Sep 13, 2010

The selection of the mining fleet can have as much of an effect on the efficiency and effectiveness of an operation as the mining method. This is not to say that inefficiencies are only attributable to inappropriate equipment selections, these aspects have many factors but are not the subject of this paper.This paper will give an overview of equipment selection processes that have been utilised to date. It will also look at the increase in application of study programs/simulations from an aspect of accuracy, as well as the importance of enabling the analysis of multiple sensitivity scenario planning. An aspect that is increasingly important in project planning with commodity market movements.Another aspect that is increasing in popularity is that of automation, what effect does this have on equipment selection? What additional aspects need to be taken into consideration when assessing Automation of equipment from the beginning of a project as well as introduction into an operating mine?Once the selection process has been finalised and equipment implemented, how do we, as an industry, 'close the loop' through analysis of estimated versus actual equipment application?

Dec 6, 2010

By R A. Binns, S Murao

The PACMANUS and Jade deposits are two active hydrothermal fields that are forming massive sulphide deposits at the Pacific rim margin. Both are associated with felsic submarine volcanic rocks and both occur in back-arc settings. However, PACMANUS is associated with almost sediment-free dacites and lies on the crest of a volcanic ridge, whereas Jade occurs in a heavily-sedimented tectonic depression associated with a basement of pumiceous rhyolite. The PACMANUS deposit is richer in Cu and Au, and Jade in Pb. Zinc, Ag, As and Sb contents are similar. Sulfide textures at PACMANUS suggest formation of Cu and Zn sulfides by simultaneous double-diffusion involving inwards-moving seawater mixing with outwards-moving hydrothermal fluid. By contrast, at Jade there is a more complex history of formation where initial growth of barite on the sediment surface, probably associated with microbial activity, formed an impervious cap which trapped higher temperature hydrothermal solutions.  

Jan 1, 1995

Bioleaching of E-Wastes

Sep 13, 2010

By T Day, I G. Robertson, G J. Lyman

"Various approaches are used in the industry for establishing procedures (sample mass estimation and method of subsampling) for sampling and analysis of gold ores. The key factors that determine the accuracy of the results that can be expected for a given set of procedures are widely misunderstood.Recent developments in sampling theory show that the estimation of the accuracy that can be expected for a given gold ore as a function of sample mass is actually a simple matter. For a given sample mass, the accuracy that will be achieved depends only on the grade of the ore and the range of masses of the grains of the gold in the ore. This, of course, demands that a reasonable estimate of the distribution or spread of gold grain masses in the ore be known. But this is something that should be known if the gold is to be efficiently recovered in the processing plant.This paper provides a simple explanation of the real facts about sampling of gold, either in the field or in the plant, and provides results for a number of cases of combinations of fine and coarse gold in an ore. The prerequisites for accurate gold sampling are:correct sampling with no loss of sample or contaminationsample preparation procedures that recognise the impact of the gold grain mass spreadpractical analysis of the sample masses required to provide acceptable accuracy.Issues of corporate governance are also discussed.Citation:Lyman, G J, Robertson, I G and Day, T, 2016. The Simple Facts about Sampling Gold Ores, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 159–172 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By K R. Vining, T E. Norgate

A study was carried out to compare the environmental impacts of the two major iron ore agglomeration processes, sintering and pelletising, using life cycle assessment (LCA) methodology. The following agglomeration processing routes, with the fuel options shown, were investigated:sintering with combined natural gas/coke breeze or charcoal as fuel, grate-kiln pelletising with combined natural gas/coke breeze as fuel, and straight-grate pelletising with combined natural gas/coke breeze as fuel. Inventory data for each process derived from the literature, and in some instances supplemented by additional simulations and calculations, were used in the study and the environmental impact categories considered were gross energy requirement (GER), global warming potential (GWP) and acidification potential (AP). The results of the study showed that the GER, GWP and AP for a sinter plant are higher than those for a pellet plant for the same amount of metallic iron in the agglomerated products. These results are partly due to higher consumption of solid fuel and flux in the sintering process. However, it should be pointed out that the study only compared substantially fluxed sinters with acid pellets that may require additional flux (and hence potentially more greenhouse gases emissions) to be a balanced blast furnace feedstock. Extending the LCA to the blast furnace process stage was beyond the scope of the current study. Within the sinter plant, the sintering stage itself is the largest contributor to the GER, GWP and AP. In the case of pellet plant, the pellet induration stage is the largest contributor to the various environmental impacts. The GER and GWP of a straight-grate pellet plant are marginally higher than those of a grate-kiln pellet plant due to the higher electrical power required by the straight grate system. The substitution of coke breeze with charcoal in the sintering process results in an increase in GER but a decrease in GWP. However, a substantial proportion of the GER is derived from renewable sources (wood), resulting in a decrease in the non-renewable components of this environmental impact. Given the source of the inventory data and the assumptions and approximations made in carrying out the LCAs, it is emphasised that the results presented in this paper should be considered as indicative rather than as definitive results for the two iron ore agglomeration processing routes considered.

Jan 1, 2006

By L R. Sousa, M He

Rock burst is common in deep underground excavations and is characterised by a violent ejection of block rocks from excavation walls. It is critical to understand the phenomenon of rock burst and particularly the failure mechanism. Laboratory experiments are one of the ways. For that purpose, a rock burst laboratory test system was developed at the State Key Laboratory for Geomechanics and Deep Underground Engineering at the China University of Mining and Technology, Beijing. A true triaxial test system, designated the Deep Underground Rock Burst Analogue Test Machine, was developed, which can transfer a stress state from three-direction-compression on six surfaces to the compression on five surfaces with one set free. The rock burst experimental system comprises an acquisition of acoustic emission signals, a high-speed recording in order to accurately record the kinetic characteristics of rock fragments ejected during a rock burst event and the possibility of infrared thermography showing the surface temperature of the samples. In this paper, analyses of typical results from rock burst tests are presented with a description of the obtained results. The mechanisms of rock burst are illustrated, and a rock burst classification is proposed based on these laboratory tests. For the control of rock burst, the constant resistance, large deformation (CRLD) bolt or anchor is presented for accommodating the large displacement of surrounding rock masses and absorbing the impact of the sudden release of rock burst while outputting a constant resistant force in response to the external load. The CRLD bolt or anchor has had practical applications in underground mines. Finally, in situ tests performed in a tunnel at Qingshui coalmine, China, are analysed in detail.CITATION:He, M and Sousa, L R, 2014. Experiments on rock burst and its control, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 19–32 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

Study on Mineral Processing Technology for a Refractory Iron Ore

Sep 13, 2010

By R Brake

The Enterprise Mine (EM) is located at Mount Isa and is wholly owned by Mount Isa Mines Limited (MIM). This high-grade copper mine extends from about 1000 m below surface to almost 2000 m below surface. A recent $400 million upgrade has taken the operation from a production rate of 1.3 Mtpa to a capacity of 3.5 Mtpa. The effects of high surface ambient temperatures in summer, combined with the depth of the mine and high virgin rock temperatures results in heat stress in the working place that, without intervention, would exceed the levels that human physiology can withstand. It would also result in significant decreases in productivity and high accident rates even where work is possible. Moreover, with a very hot and deep mine, the needs of æegressÆ and entrapment of workers during a mine emergency must be carefully considered. Enterprise Mine has taken a æsystems approachÆ to the issue of working productively, healthily and safely in heat. This involves setting limits of thermal stress for workers, understanding productivity decrements when working in heat, establishing productive and healthy environmental targets, developing engineering solutions to meet these targets, creating a well-educated workforce with respect to working in heat and then developing health protocols to ensure workersÆ health is protected. Refrigeration must be added to the mine to provide acceptable and productive conditions underground. By the time the mine is commissioned in 2000, Enterprise mine will have an installed refrigeration capacity of in excess of 40 MW(R). The ventilation engineering principles proven over many years at the other Isa underground mines are tailored to æfloodingÆ the mine with air to remove the heat, which is the main contaminant. This principle will not work at the Enterprise Mine, for reasons discussed below. With the underlying ventilation principle no longer satisfactory, a complete review of the entire ventilation principles and engineering solutions was required for the Enterprise Mine.

Jan 1, 2000

Currently all engineering schools face a common problem, an ever expanding technological base which must be presented to students within a fixed time period. Traditionally the programmes of study taken by engineering students destined for employment within the mineral industry include formal instruction in aspects of management to an extent greater than that presented in other engineering disciplines. Providing an adequate coverage of an expanding technological base within a fixed time span can lead to a reduction in the time available for 'non-technical' subjects, such as 'management'. This situation calls for periodic review of course contents and allocations of time. Following consultation with an Advisory Committee representing the mineral industry, mining research establishments, and kindred teaching institutions, the University of Melbourne has revised its mining programme. This programme is offered as an example of how aspects of management such as communications, economics, labor

Jan 1, 1980

By R Sridhar, M Fe, W G. Bacon

The problems of magnetite build-up have plagued the non-ferrous pyrometallurgical industry for many years. To better understand these problems, a study was undertaken to determine the thermodynamic variables that affect the behaviour of magnetite under different smelting conditions. Equilibration studies were performed in the nickel smelting systems of matte-gas and matte-slag(silica saturation)-gas. The relationship of thermodynamic variables such as temperature, sulphur and oxygen partial pressure and matte grade on iron and magnetite activities were calculated and the significance on smelting parameters such as metal losses and partition coefficients were defined. The experimental data from this study were employed to develop practical methods which could be used to control the build up of magnetite, as well as to obtain additional metallurgical benefits. In general, a lower sulphur partial pressure and higher temperature operation was shown to enhance the metallurgical benefits of nickel smelting by decreasing the magnetite activity. Operating in this manner can also have added benefits such as higher metal recoveries, more efficient vessel utilisation and efficiency and lower smelter emissions at equivalent or higher primary furnace matte grades.

Jan 1, 2000

By R Miller, D Hawcroft

The business environment is never still and there has been enormous change in demand, technology and opportunity during the last decade. In order to succeed it is necessary for organisations to change the way work is planned, scheduled and carried out. This is necessary just to survive over time. The success or failure of the business is strongly influenced by people; the way they work, the way they are guided and their feelings about being part of both a team, as well as an organisation. Our Sustainable Integrated Management System (SIMS) philosophy is built on the belief that people want to be constructive and creative and it is their environment and working relationships that influence how their energies are directed.

Jan 1, 2000

Any hypothesis for the origin of the Otago gold-quartz lodes must account for the following observations. 1. Southeast of Glenorchy, where the schists hosting the lodes are comparatively unaffected by Neogene Alpine Fault deformation, the dominant strike of the vein systems is NW-SE, parallel to the axis of greatest post-metamorphic uplift in the Otago Schist belt (Paterson, 1986). 2. The lodes are fault-hosted, with some developed along steep, low-displacement normal faults (eg Barewood, Bendigo, Nenthorn), implying NE-SW extension, and some developed along low-angle thrusts (eg Macraes) implying, in apparent contradiction, NE-SW contraction (Teagle et al, 1990). 3. The mineralising fluid was of metamorphic origin (McKeag and Craw, 1989), but while some of the lodes developed in a mesothermal environment at considerable depth (eg ~10 km for Macraes), others appear to have formed at very shallow depth (eg <1 km for Nenthorn) (Craw and Norris, 1988). 4. The timing of the mineralisation is generally poorly constrained but postdates the main Rangitata schist metamorphism. It probably initiated during early Cretaceous exhumation and unroofing of the schist belt (140 - 120 Ma?) and may have continued well into the Tertiary (Craw, 1989). Estimates for the relative ages of the different lodes are largely speculative but, based on pressure estimates from fluid inclusion studies, Macraes likely represents the deepest and oldest lode system while Nenthorn (just 12 km to the southwest) is perhaps the shallowest and youngest (Craw and Norris, 1988).

Jan 1, 1992

Laboratory testwork was carried out on an overall orebody composite, of 2.9 per cent Cu and 4.2 per cent Zn, prepared from drill core taken from the Currawong fine-grained, copper-zinc massive sulphide deposit near Benambra in Victoria. While 90 per cent of the copper was readily recovered in a concentrate of 20 per cent Cu, after grinding to 95 per cent passing 38 microns, zinc responded poorly to conventional flowsheet/reagent regimes. Experience elsewhere with the use of reverse cleaning, to separate pyrite from sphalerite, led to a series of tests in which better (but still modest)metallurgical results were obtained. The best result was a zinc recovery of 55 per cent in a concentrate of 50.5 per cent Zn. The major loss of zinc occurred in the reverse cleaning stage where the unit recovery of zinc was similar to pilot plant results achieved at Mount Isa Mines on similar feedstock. Diagnostic mineralogy suggested that an overall zinc recovery of 70 per cent was probably the practical upper limit, at a 50 per cent Zn grade.

Jan 1, 1999

By W C. Burton, J S. Kuszma, T O. Aspinall

The environmental impact of mining and evolving environmentallegislation has received increased attention worldwide in the last two decades (Bradfield, Shultz and Stone, 1996). The potential impacts associated with unstable spoil dumps from mine operations is the focus of concern both by the mining industry, environmental regulatory agencies and members of the public. Engineered slopes of mine spoils may be stable at the end of construction, but they can deteriorate over time. There is thus the need to increase the base of knowledge on the existing practices of spoil dump design and rehabilitation. Efficient engineering design and systematic economic evaluation of spoil dump reshaping techniques for mine rehabilitation assists in maintaining the expected standards of environmental compliance. As part of the overall approach for effective engineering design ofspoil dumps, a comprehensive, computational and efficient tool isrequired for assessing the economics and productivity of existing spoil dump reshaping practices for efficient mine rehabilitation. Such a design tool is useful in linking current spoil dump environmental management practices with engineering design planning and economic impact evaluation. This paper identifies the processes for the economic impact evaluation for existing spoil dump reshaping practices and proposed final site dump designs. Selection of an efficient spoil dump design at optimum costs will ensure operational efficiency. A case study is presented identifying economic impact evaluation in earthmoving equipment selection and the costs involved for the reshaping of spoil dumps to that of varying final site designs.

Jan 1, 2000

By A G. L Pratt

Change and its relationship with the introduction of new technology is a constant of human history. The mining industry has many examples of this relationship. This record contrasts with its present day struggles to move beyond a public perception of being just ‘dirty, dumb and dangerous’. The drivers for the introduction of new technology are frequently listed as the occupational health and safety of people working in the mines, reductions in direct operating costs, and increases in productivity.This paper discusses the issues that a mining business needs to deal with to implement new technology with the best possible conditions for success. It comments on how the strategic and tactical components of technology planning relate to and interact with change management. The central discussion is directed at the role that people play in the successful implementation of new technology. The introduction of autonomous underground haulage equipment provides a background for the discussion of this topic.The paper uses case study references, equipment supplier information and research findings. The aim is to offer a high-level view of the issues a mine operator needs to consider when approaching the introduction of new technologies for underground mining.CITATION:Pratt, A G L, 2017. Technology change in underground mining – things to consider, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 103–114 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017