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By Jin C, Shu H

The effect of operating parameters of a shaking table on the separation of mixed quartz-magnetite artificial feed has been experimentally investigated by use of laboratory-scale shaking table. Based on a great number of experimental data collected, the multi-variate non-linear model of shaking table has been developed. The model allows for the calculation of the product grade and recovery. A computer model has been programmed, for inclusion in a software package for the simulation and optimisation of shaking table if the feed characteristics and the concentrate grade are given.

Jan 1, 1993

By A. W. CAMERON

Over a 4 hr period of steady plant operation samples were taken at regular intervals from points within the grinding and flotation circuits. Size fractions of each composite sample were analysed for lead and zinc values and a comparison made of the behaviour of the lead, zinc, and gangue minerals, size by size throughout the whole circuit.Analysis of the breakage behaviour using dynamic mathematical models gave the rates of breakage of each size fraction of each main component. Simulated grinding experiments showed that the main grinding circuit had some reserve capacity.In the lead flotation circuit all lead values between 150 mesh (Tyler) and 5 microns had excellent flotation characteristics, and a major proportion had a high rate of flotation which was practically the same for all sizes. Increase in overall lead recovery would require improvement of the flotation behaviour of ultra-fine lead minerals. These were slow floating and were responsible for approximately half the lead losses in the final zinc concentrate and one-third of the lead losses in the final tails.All sizes of zinc values between 100 mesh and 7 microns floated well and the performance of the zinc flotation circuit was mainly limited by the relatively poor flotation of the very fine zinc values. Approximately 60 per cent of the zinc lost to the final tails lay within the minus 7 micron fraction.The overall flotation conditions were conducive to very good selective flotation of the major proportion of the values and limitations in metallurgical performance were mainly due to the properties of the ultra-fines.

Jan 1, 1971

By Millett R

In January 1989, Western Mining Corporation (WMC) acquired the Perseverance and Rocky's Reward orebodies and associated infrastructure from the Agnew Mining Company (AMC). AMC had closed the operation in August 1986 and it had been on care and maintenance since that time. To return the operation to full production as quickly as possible it was planned to mine the Rocky's Reward orebody by opencut mining and treat this ore whilst the underground Perseverance workings were rehabilitated. Removal of overburden from Rocky's Reward thus commenced immediately with a target of April 1989 for delivery of the first ore to the concentrator. Extensive rehabilitation and upgrading of the concentrator commenced in late January, and continued in stages for an 18 month period. The first stage consisted of overhauling all existing equipment and completing a crusher upgrade commenced by AMC prior to the mine closure. During this period, it was necessary to recruit a workforce and re-establish all the required support structure. In late April the plant commenced commissioning trials on mullock. The first ore was crushed on the 11th May 1989 and concentrate produced the following day. From May 1989 to June 1990 the plant was producing nickel concentrate whilst further upgrading continued. During this period, the flotation capacity was tripled by installation of a bank of eight Wemco 144L flotation cells in rougher-scavenger duties and two 12 metre by 2 metre diameter columns in cleaning duties. The existing vacuum drum filters were replaced by two Larox PF32 pressure filters, eliminating the need for solar drying and allowing the flash drier to be fed direct from the filters. These, along with a major borefield expansion and further work to the crusher increased the nominal plant capacity from 600,000 to 1,000,000 t/yr. The plant achieved the 1,000,000 t/yr rate in April 1990.

Jan 1, 1991

By R Berry, S G. Walters, J A. Hunt, D Collett

The texture of an ore type is fundamental in understanding the metallurgical behaviour of an ore. This study will show examples of how quantified textural attributes (mineral shape, grain size and mineral association) can be obtained from automated and scanning electron microscope (SEM)-based microscopy and utilised using advanced image processing techniques. Examples will be shown of integrating quantified and semi-quantified meso- and macro-scale textural attributes as well as how they relate to texture-based visual logging systems. The implications of texture for processing behaviours such as comminution, liberation and recovery will be discussed. This research is part of a major collaborative geometallurgical project undertaken at the Centre of Excellence in Ore Deposits (CODES, University of Tasmania) and the Julius Kruttschnitt Mineral Research Centre (JKMRC, University of Queensland). The authors wish to acknowledge financial support and permission to publish from the sponsors of the AMIRA P843 GEMIII project.

Jan 1, 2008

The Key Centre for Mines consists of the School of Mines of the University of New South Wales and the Departments of Geology and Civil and Mining Engineering of Wollongong University. The Key Centre for Mines/International promotes, markets and develops overseas activities in applied geology, mining engineering, mineral processing and extractive metallurgy specifically in response to the perceived needs in the region for mineral resource and other related earth-science based development. the Key Centre for Mines/International will be involved in the overseas marketing of formal courses; special training activities such as short courses and in-house programs; technical and educational consultancy; research and development projects, and in the establishment of regional links through twinning, exchange and various network arrangements with other organisations in the region. Activities which are now being developed include a training program for Korean mining engineers and geologists, teaching and curriculum development in the Mineral Resources Engineering Faculty of the University Sains Malaysia and a staff development proposal for the Department of Geotechnology of Khon Kaen University, Thailand

Jan 1, 1990

By Durao F

A multi-layer feed-forward neural network was trained (using the error back-propagation algorithm) to learn a subset of rules designed to stabilise the performances of the copper flotation section of a complex sulphide processing plant and then tested in order to evaluate its expert performances. Two types of neural networks were compared: the classical ones, fully connected between one layer and the adjacents (with different architectures), and entropy networks, partially connected and generated according to a methodology that simplifies its building up. The advantages and drawbacks of both were analysed and compared with classic (rule based) expert systems.

Jan 1, 1995

A resume covering currently accepted views on blasting vibration measurement, human response, and criteria for damage is presented as background information for readers who are not conversant with blasting vibrations. This is followed by sections on vibration level estimation and blasting techniques to control vibration. Emphasis is placed on making use of the scatter in the delay intervals of half-second delay detonators, the use of smaller explosive charges for early delay numbers, and the non- use of zero-delay (instantaneous) detonators in cer`a. n cases.

Jan 1, 1976

As a number of underground fires have unfortunately happened in the Broken Hill mining district, the writer trusts that a paper dealing with such a subject may prove of interest. To simplify matters, the subject is classed under three mainheadings- I Origin of fires; II Methods of subduing them; III Precautions to minimize the risk of their occurrence.Underground fires may be started in three ways - arson, spontaneous combustion, or carelessness.With regard to the first-mentioned cause, direct evidence is usually lacking to prove that any fire has been caused maliciously; Though definite proof of spontaneous combustion having been the cause of a mine fire has not been brought forward, nevertheless it should be considered, especially in the case of sulphide ore bodies of a more or less friable nature. The writer has been informed on reliable authority that in an open stope on the...

Jan 1, 1911

By A G. L Pratt, G F. Dunstan, A Leonforte

The selection of the material sizing and mine dewatering systems are important elements in the development of a large-scale, high tonnage (greater than 4 Mt/a) underground hard rock mine. The sizing system will influence the size and type of the ore haulage system and therefore how the underground project is developed. With more underground developments considering or implementing caving methods of mining, the selection of the material sizing systems is also influenced by the caving fragmentation. Traditionally, crusher systems are used for material sizing in large hard rock mines, with the crusher installation and its ancillary equipment representing a substantial capital investment. Underground cave mining type operations generally express themselves with large surface subsidence areas, which can lead to large inflows of water from major rain events or purging underground aquifer systems. To minimise disruption to mine production, the dewatering system needs to be sized, with consideration to both storage and pumping capacities. The balance between storage and pumping capacity is assessed to provide the optimal economic solution with the appropriate risk measures. This paper outlines a process for the selection of material sizing and dewatering systems for large-scale caving operations. This process is illustrated with information drawn from NewcrestÆs Ridgeway Deeps Block Cave project. The Ridgeway Deeps Block Cave is located directly beneath the existing Ridgeway Sublevel Cave Mine.

Jan 1, 2008

Some fundamental aspects of recent single-particle fracture studies are reviewed. Findings from this research shed new light on the utilisation of energy during comminution operations and provide useful pointers to new research directions that could lead to significantly better comminution machines. Two methods for quantitatively predicting mineral liberation during comminution are reviewed. These methods have been developed into useful practical procedures, but they are almost unknown in the mineral processing community. Their use should promote the consideration of mineral liberation as an important variable to be considered during the design and operating control of comminution circuits.

Jan 1, 1993

Until recently, nickel laterite projects have been largely ignored, due to their supposedly higher treatment costs compared with sulphides, and to their perceived processing difficulties. A number of laterite projects in the 1970s were abandoned because of high capital and operating costs, while others experienced severe technical difficulties. Conventional wisdom had it that laterites would not be exploited until most of the sulphide orebodies had been depleted. Why then, have Australian mining and exploration companies started a resurgence of interest in the treatment of nickel laterites? It all began with the Bulong project, which has been under study since 1987, while more recently two further projects, Murrin Murrin and Cawse, have been initiated and are being fast-tracked to take advantage of the current high nickel and cobalt prices. A further project in NSW, Syerston, has also been investigated at bench-scale, but no further development has yet been announced. All these projects have the following advantages: 1. Good location near a major mining centre and,reasonably close to power, water, roads, accommodation and a developed service industry. 2. Straightforward, low cost mining. 3. Low cost of acid or sulphur. 4. Good to very good cobalt credits. In addition, there have been significant technological developments in the design and operation of high pressure autoclaves and high rate thickeners, as well as solvent extraction and electrowinning technology. This has helped to decrease capital costs and technical risks, and has allowed the development of alternative flowsheets to the existing laterite operations (Taylor, 1996).

Jan 1, 1996

By T Elkington, A Finch

The theory of constraints (TOC) is a business improvement method that focuses on exploiting a business’s bottleneck to deliver the highest possible profit. Early applications were mostly in the manufacturing industry; however, the theory in itself is completely generic and has now been applied widely in other industries such as services, retail, software and distribution, amongst others. The intent of the approach is attractive – it focuses on the ‘silver bullet’ rather than ‘death by a hundred projects’, and it focuses on growth rather than cost cutting. Application within the mining industry has been limited to date, although there are a few applications emerging. This paper discusses how TOC can be applied to maximise value during the project planning phase and how to maximise profits when the mine is operational. The paper uses two case studies to illustrate the approach. Case study 1 uses the approach to improve tactical mine planning, which delivers an increase in revenue of 58 per cent. The second case study is a strategic mine planning example that delivers an increase in value of 77 per cent.CITATION:Finch, A and Elkington, T, 2014. Application of the theory of constraints to strategic and tactical mine planning, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 129–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By B Indraratna, A Dey

The surface geometry of a rock bolt plays a very important role in the rock/resin/bolt load transfer mechanism. Very little work has so far been reported on the influence of the bolt surface geometry on the bolt/resin interface failure mechanism. This paper examines the behaviour of bolt surface roughness under constant normal stiffness condition in the laboratory. To study the shear behaviour of the bolt/resin interface a series of shear tests with an initial normal stress between 0.1 to 7.5 MPa has been conducted on the flattened bolt surface of two most popular bolt types currently being used in Australia. Bolts with deeper ribs offered better shear resistance at low initial normal stress conditions whereas bolts with shallow and closer ribs offered better shear resistance at high normal stress conditions. The maximum dilation occurred at a shear displacement of 60 per cent of the rib spacing irrespective of the bolt type and depth of the rib.

Jan 1, 2000

By Tucker G, Clark A, Young M. F, Johnston M

Mount Isa Mines has made a huge commitment to process control in milling. Yet in lead zinc we still failed to achieve a steady operation. Comparisons with manufacturing plants showed the key difference was failure to control plant inputs. Lead

Jan 1, 1998

By Bhattacharyya A. K>

The Pemali Open Pit Mine is situated in a small island called Bangka in Indonesia. It produces approximately 165,000 m3/year of tin ore with an average grade of 3.67 kg/m' of tin from a primary deposit. The deposit occurs at the rim of a granitoid intrusion within sedimentary beds. The rock formations, all extremely weathered, and the overlying alluvium, are exposed to a rainfall exceeding 3m/year. Serious slope stability problems are experienced at the mine, despite using overall pit slopes of 20¦-29¦, the latter resulting in a stripping ratio of 4:1. This paper outlines a computer based back analysis of a major slope failure involving some 250,000 m' of material which occurred on the west wall of the pit in February, 1984. The findings from the analysis, together with other information, are used to examine the stability of the east wall of the pit, where tension cracks developed later. The results indicate that the large influx of water was the most significant cause of such slope stability problems and a more intensified water management programme would be beneficial.

Jan 1, 1989

By C Vejrazka, A Wyllie

A common problem faced by underground mining operations around the world is airborne dust sourced from production and auxiliary processes. In most underground mining methods, air is generally directed through a limited number of drives and is thus more effective at carrying dust away from operational areas quickly. In a block caving operation, there are a number of ways to set up ventilation systems. In its simplest form the air is entering the extraction level through access drives and then split over the number of extraction drives—based on the pressure differences—without being regulated. This is the case at Northparkes Mines. Larger operations and panel caves most often utilise designated ventilation levels and ventilation raises with some form of regulation to ensure adequate airflow to all work areas.Northparkes Mines utilise electric loaders as a productive means to transport ore to the run-of-mine (ROM) bin, which have the added advantage of allowing the mine to require less airflow through the extraction drives as dilution of exhaust gases is no longer required. Dust was controlled during the operational period of the previous two block caves by using water spray bars in each of the drawpoints, which were seen as the main source of dust. These drawpoint spray bars only wet the surface of muck piles and require a lot of water to achieve an effect on the overall air quality. The drawpoint sprays can be remotely operated from mine control, whenever a loader is sent to bog a particular drawpoint. A significant amount of airborne dust is also generated during loading as rilling of material occurs, with further dust being generated during tramming and dumping activities as only limited mixing of the water and ore occurs. The water sprays are ineffective at precipitating dust that has already become airborne.When built, the currently operational E48 cave was fitted with drawpoint water sprays. As the cave is in a different orebody with higher silica content, the water sprays were not able to keep airborne dust and thus silica quantities under control efficiently. It was therefore necessary to find more sustainable solutions. The problem was further intensified by the concurrent load-haul-dump (LHD) processes across multiple extraction drives and tipping points, as well as secondary breaking, using non-explosive blasting and development activities occurring nearby.This paper describes the practical approach taken at Northparkes Mines to reduce personal dust exposure on the E48 extraction level. As the extraction level is one of the main contributors to airborne dust at the mine, it is believed that much can be learnt by focusing improvement efforts initially on this part of the mining process and later applying the effective solutions in other parts of the mine.CITATION:Vejrazka, C and Wyllie, A, 2014. Reduction of airborne dust on the E48 extraction level at Northparkes mines, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 227–232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

The outcome of future metallogenic research will be important to everyone because it will. have a profound impact on our ability to find new deposits of non-reservable mineral resources. Failure to replenish our mineral stocks will threaten man's economic and social well-being, and it is vital that future directions of metallogenic research are considered carefully to ensure that research funds are applied wisely to underwrite our future.Today we are witnessing the declining phase of the era of easy exploration. The rate of discovery of shallow orebodies is slowing. This is very evident for base-metal deposits but is becoming increasingly apparent for gold deposits. The easy exploration era was marked by a heavy reliance on exploration techniques capable of directly detecting mineralization. These include simple prospecting methods as well as a host of geochemical and geophysical procedures and tools that enable explorers to pin-point regions' of mineralization within the upper couple of hundred metres of the Earth's crust. The role of

Jan 1, 1990

By M J. Nimmo

extremely powerful tools for building predictive and generative models. ML can be used for building highly accurate regression and classification models. But without careful data science and statistical analysis, a regression or classification model could be highly biased and completely wrong – and we may not even realise. An example rock density estimation task will be used to illustrate the potential gains and possible pitfalls in using ML and AI in Mineral Resource estimation. What could possibly go wrong? Nothing! For most simple regression or classification problems, very little. For density estimation, using the global mean may be all that is possible, but the resource classification would need to reflect the uncertainty in global estimation of tonnage. Everything! From data collection and measurement, from selecting ML and AI techniques and designing the analysis workflow to our own cognitive bias. The things that could go wrong are vast and may include but not limited to asking the wrong question, not asking questions, data bias, measurement errors, insufficient data coverage, not collecting the right variables, not collecting enough observations, collecting clustered samples, unbalanced data, filtering out data without reason (outliers), clipping data (outliers), relying on automatic feature selection, including irrelevant variables, excluding relevant variables, geological interpretation, changing context, blindly following best practice, splitting small data sets, subsetting large data sets, using the wrong tool for the task, insufficient budget to complete the analysis, not allowing enough time for testing and experimentation (the science), focusing too much on building the model (the engineering), not learning from the data, our assumptions, our preconceptions, and our skill. This paper will explore the question of how training regression models to predict rock density are affected by gaps in the data (missing observations and missing variables). What could possibly go wrong?

May 24, 2023

Its two years since we have presented at this conference and since that time we have made significant progress with our coal developments in New Zealand. In 2005 we held the Whareatea West exploration permit and had just completed the purchase of the Cascade mine. Today, in addition to Cascade and Whareatea we now have the Takitimu Mine, Eastern Coal Supplies, our coal blending and distribution facility in Timaru, prospecting permits at Ohai and Orepuki and an established customer base underpinned by the contract to supply FonterraÆs Clandeboye plant commencing in September 08. For this presentation I would like to take you through our purchase and development of the Takitimu mine.

Jan 1, 2007

By Kilgour I

The installation of a final cleaning column at Ok Tedi Mining Limited was carried out to increase final concentrate grade in order to reduce concentrate handling, shipping and treatment charges and to reduce penalty payments. To fast-track the project a decision was made to install a full-size column on one of the two parallel circuits, designed on information readily available and utilising the experience of mill staff and an engineering consultant, rather than delay installation while a pilot scale program was conducted. A 3.66 m diameter by 12.8 m high column was installed to produce 40 t/h of final concentrate from a combination of rougher concentrate and recleaner concentrate. The column design and sparger system were by Cominco Engineering Services Limited.

Jan 1, 1991