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By K Ellis, K Quast, R Newell

The use of ammonia as a leaching agent in the recovery of copper from ores and concentrates has a number of potential benefits. These include the ability to treat ores with an acid consuming gangue, non-corrosivity, the insolubility of iron in the solution and increased selectivity. This paper reviews the previous and current use of ammonia based leaching systems for copper recovery and presents the results of a laboratory investigation that involved leaching of a copper concentrate and a low-grade ore. The effects of the operating variables (particle size, oxygen addition, agitation and temperature) are discussed. Of these, the particle size had the greatest effect, with decreasing size giving improved leaching rates and recoveries. The possibility of using ammonium salts in heap leaching is also discussed, and the results of some small-scale column leach tests presented. Possible methods for recovering the copper from the leach solution are outlined, and the types of ores and concentrates for which ammonia leaching may prove to be a viable alternative processing route are discussed.

Jan 1, 2000

The great philosopher, Marshall McLuhan, is said to have stated that the use of forecasting as a means of guiding future actions is akin to driving an automobile through observations made in the rear-view mirror! In effect, in forecasting it is assumed that there will be an orderly progression from the past into the future, and that the model will be sufficiently unvarying for use to gauge both the directions and the rates of change. The concepts of forecasting have served man well in disciplines in which the relationship between causes and effects can be clearly demonstrated; such as between rainfall and crop yield, for example. These are of no value, however, when conditions change rapidly and unpredictably, or when there is no model at all. Even worse, under such circumstances our preconceived notions may cause us to make some horrendous errors in judgement. Such are the risks at present in attempting to make an assessment of the educational needs of the minerals industry for the coming century! The model, and the conceptions that we have had of the linkages between cause and effect are in disarray. Minerals markets are chaotic, and there is almost no ability to forecast trends in metal values. Linkages between supply and demand seem tenuous. Internationally, producers are struggling for survival. Mine closures, temporary shutdowns, and reopenings are frequent occurrences. Decision-making under uncertainty is probably one of the most certain things about the world mining industry Today!

Jan 1, 1986

Over the last thirty years production of heavy minerals from Australian deposits has dominated the world market. The main incentive has been to suoply the raw material for titanium dioxide based pigments. These ~ninerals include ilmenite, rutile, leticoxene and more recently, synthetic rutile. Inevitably the viabilit/ of developing placer type deposits has seen influenced by other heavy minerals present, such as zircon and monazite, but these have been of secondary importance. For most of the sixties and seventies, Australia supplied the 'najority of free world rutile and zircon, and a large proportion of the ilmenite. With the run-down of rutile- rich reserves in eastern Australia, the emphasis has s:iifted in several countries, including Australia, to fill }the gap with i l Wen i to and its derivatives, leucoxene, synthetic rutile and titanium rich slag. over the next 15 - 20 years, as high grade beach placers in Western Australia are mined out, less traditional sources for mineral sands products will be opened up. Low grade placers (particularly those dominated by ilmenite) will be reassessed in Australia, U.S.A., Africa and Asia, and exploration will shift from beach and dune environment, to heavy mineral concentrations in alluvials, lake deposits and continental shelf deposits. At the same time, production of anatase and bastnaesite will be expanded, as required, from the huge resources contained in carbonatites in 3razil, U.S.A. and China.

Jan 1, 1986

Much has been written about leadership over the years. It is probably one of the most written about but least understood and defined concepts in business. Leadership and management are often confused and blurred, and inspirational words such as mentor, coach, motivator and the like, are often interspersed when describing a leader. There are a few things we do know about leadership:The only thing common to all leaders is that they are different.Leadership is not the sole domain of business; it applies to every aspect of human endeavour. We are all required to lead at times, and we all have it in our ability to lead. There is no set of predetermined competencies, which a leader must possess to be effective. Hence there is no course in the world that can teach you to become a leader. There is no such thing as the perfect leader. Leadership is a verb, not a title; you actually have to do it to be judged a leader. All leaders no matter how you define the term, must leave a legacy. Thus in the busy world we all live in, what are the lessons in leadership that we can all learn from, that will assist us all in our pursuit of leadership. The purpose of today is to put forward a framework for leadership that I have been researching and working on for many years. It is not the definitive framework, merely a framework. Out of today you will take your own collective thoughts, learnings, observations, experiences, education and training, and collective wisdom, and apply it to yourself.

Jan 1, 2004

Anyone who has driven backwards using only their rear view mirrors knows how difficult it is to avoid spinning the steering wheel the wrong way. So why run your mine that way? Traditionally Reconciliation has focused on the past performance of the mine. In this paper we make a case for Prognostication û the act of forecasting or predicting something in the future from present indications or signs. Reconciliation is a common activity carried out at most mines around the world. Countless geologists and engineers spend hours poised in front of spreadsheets diligently comparing how their resource/reserve model, grade control, and survey pick ups compare to what was actually produced. The result is usually a group of factors, which are applied to future estimates in an attempt to better predict how the operation may perform. Unfortunately, if the road ahead isnÆt the same as what you have just been down, youÆll be æoff-roadingÆ in no time! An alternative is to constantly collect and analyse key measurements that are used to calibrate critical estimates in an iterative process. When variations occur, they are analysed and corrective action is taken to ensure the estimates and measurements realign. In this way the estimates become forecasts and can then form the basis for decision making to ensure that what does happen in the future will match the plan or schedule. By automating this process, some mines have been able to be proactive on a daily basis in order to improve the overall performance of the operation. This paper outlines the key estimates and measurements used for reconciliation, details the characteristics of an automated web based information management system to facilitate the process and provides some insights about how mining operations might move beyond reconciliation.

Jan 1, 2003

By J Q. Shi, M Karakus, Y Liu

Predicting the spatial distribution of rock mass properties in cave mining is a critical challenge. In this study, we introduce a novel machine learning-based model to advance our comprehension of rock behaviour. This model specifically focuses on the spatial distribution of rock mass and mechanical properties, a crucial aspect of our understanding of rock mechanics. Our model is inspired by the recognition that neighbouring information serves as crucial prior knowledge for predicting the spatial distribution of these properties, wherein closer neighbours are likely to exhibit similar characteristics. To effectively capture and model these neighbour relationships, we design a neural network-based model to map the spatial locations within the data set into a new highdimensional space. Within this transformed space, we utilise Euclidean distance to identify N neighbours. Leveraging these neighbours, we introduce a straightforward yet highly effective approach—label propagation—to construct a graph that illustrates neighbour relationships. This graph not only facilitates the prediction of the spatial distribution of rock mass properties but also offers a measure of uncertainty for these predictions. We validate the proposed method using a real rock data set and showcase its efficacy in capturing intricate relationships and distributions within rock properties, enabling precise predictions across diverse spatial scales. Our results underscore the potential of machine learning-based approaches to revolutionise the field of rock mechanics, providing valuable insights applicable to geotechnical engineering, mining, and other sectors where an accurate understanding of rock properties is paramount. This model has direct practical implications, offering a new tool for geotechnical engineers and mining professionals to enhance their understanding and prediction of rock properties, thereby improving safety and efficiency in their operations.

Sep 1, 2024

By Zhang Y. D, Zhang R. X

A new decision-making approach of artificial neural network system with hierarchic structure is presented. The fundamentals of network topology, node functions and network training are introduced. A neural network system with hierarchic struct

Jan 1, 1998

Following a summary of aerodynamic principles and the changes imposed by the process, areas important to the operator are then enumerated. These include furnace lines, cooling and casting technology, coke properties, gas distribution and others. Questions are raised on the implication of lowering the hearth substantially below the tuyeres and about the status of stack injection. Finally, the future developments are identified as being those associated with gas volumes required to pass through the furnace stack per unit time or per tonne of product.

Jan 1, 1975

By F

Ore reserve estimation has been described as the most individualistic, the most prickly and even the most controversial of all the technical aspects of the mining profession. This symposium is a great opportunity to look at the present state of the art and full marks must go to the Sydney Branch for organi- sing it at this time. The first essential of good ore esti- mation is probably an awareness of the uncertainties involved, and the possible impli- cations of these uncertainties.

Jan 1, 1979

It is with great pleasure that I accepted the invitation to make a closing address to this Congress particularly as it is here in Brisbane. The main duty of the International Mine Ventilation Congress Committee and in particular the chairman is to ensure that these conferences are held every four to five years in suitable locations. My main role over the last four years has been to promote holding this Congress in Australia and it was a great relief when the Queensland team and the Australasian Institute of Mining and Metallurgy accepted the challenge in November 1986.

Jan 1, 1988

The successful operation of diesel equipment underground does not entirely depend on selection of robust, reliable, easily maintained machines. Results are also heavily influenced by the following factors: Design and condition of the operating area. Skill of operators. Correct maintenance facilities. Experience, skill and initiative of maintenance personnel. If the mine layout does not allow access to a central workshop area, the effect of any shortcomings will be magnified. The best results will only be obtained by close co-operation between mining and maintenance departments right from the initial planning stages.

Jan 1, 1977

The expense of mine environmental and planning process approvals is a fundamental and proper part of mine planning and feasibility costs. It is not a cost that should be the subject of challenge nor is it a cost that should be avoided. However the additional process approval costs incurred by bureaucratic delay, process duplication and administrative incompetence is a scandal and a deterrent to investment.

Jan 1, 1992

By T Harrington, M Cox

There have been many changes in the Australian mining industry during the last 30 years. One of the most dramatic changes, from a geological perspective, is the reduction of in-house geological staffing and an ever increasing reliance on contract and consulting services. As a result, there has been a change in the way geological information is generated, managed and retained within the industry. This paper describes the changes that have taken place in the industry, provides two case studies of how companies manage their geological Intellectual Property and reviews some of the issues associated with management of in-house and outsourced geology services.

Jan 1, 2009

By Morland R, Peck R

The Joint Committee of The Australasian Institute of Mining and Metallurgy (AusIMM) and the Australian Mining Industry Council (AMIC) have published a Code for the Reporting of Identified Mineral Resources and Ore Reserves. The Code is the result of an initiative begun in 1971 to achieve industry self regulation of Resources and Ore Reserves reporting which resulted first in guidelines for reporting standards but which have now been incorporated in ASX Listing Rules as a Code with significant sanctions ensuring compliance. This paper describes the background to the Code, its key provisions, and comments on practical aspects of working with the Code and compliance issues.

Jan 1, 1990

By K Heiskanen

Flotation is affected by several factors, part of which depends on the mineralogical characteristics of the ore and part on process variables. Sulfide Ni-Cu ores occur typically in mafic and ultramafic igneous rocks. Serpentine minerals are also common. As a consequence of metamorphosis, sulfides and secondary minerals may be finely disseminated in an altered ore matrix. The floatability of minerals depends also on process variables. Oxidation of sulfide particles, process iron and dissolved ions in process water affect the behaviour of sulfides. The effects of some essential factors on flotation of Ni-Cu ores are considered.

Jan 1, 2005

Deformation of the lithosphere by tectonic forces is investigated from both observational and theoretical standpoints. Global and regional geophysical data bases, coupled with the means for their rapid display and analysis, facilitate recognition of areas of the con- tinents and oceans where the response of the lithosphere to these deforming processes might fruitfully be studied. Gravity anomalies, from Seasat altimeter data and from land and shipboard measurements, provide critical infor- mation on the isostatic state of deformed lithosphere and therefore on its thermal and mechanical properties.

Jan 1, 1987

Gold recovery by catalytic copper ammonium thiosulphate solution has been studied. Such a process strategy is very attractive for leaching certain difficult-to-treat ores and presents lessened lixiviant toxicity compared to cyanide. Newmont Gold Company has evaluated the ammonium thiosulphate heap leach process for gold recovery from low-grade carbonaceous sulphidic refractory ores following biooxidation. The ammonium thiosulphate leach process has been studied in laboratory, pilot plant and demonstration scale. Satisfactory test results support the continuation of process development. However, the thiosulphate leach chemistry was found to be very complex. Maximum control of the stability of the leaching system is a key factor for success, especially for the heap leach process. Important solution chemistry is discussed in this paper.

Jan 1, 1997

By C Glassock, P Bodon, M Elias

Computer simulation is a well-accepted tool for modelling the behaviour of large or complex operating systems. Less common is the use of simulation as a design aid, but FluorÆs simulation group regularly applies discrete and continuous simulation models to assist with optimisation and risk management in a wide variety of mining, mineral processing and logistics applications. To demonstrate the wide applicability of simulation modelling as a design aid, this paper describes three case examples from FluorÆs recent work that cover both discrete and continuous operations.

Jan 1, 2003

By J S. Simmons, J G. Skousen

This project evaluated the performance of nine passive treatment methods by studying 137 treatment units in eight eastern states. Performance was normalised according to construction cost, projected service life and kilograms of acid load treated. Results were dimensioned as $/kg of acid load treated/year. These costs were then compared to those of chemical treatment. Sites that achieved acid load reductions at costs below those of chemical treatment were considered successful. In addition to evaluating the performance of the treatment methods, this paper describes the various passive treatment systems, their applications and performance data for individual treatment units.

Jan 1, 2003

The reasons for using SFRS, including the way a SFRS performs in comparison to plain shotcrete as a support element in mining tunnels, are discussed. The mechanisms by which steel fibres reinforce shotcrete and the need for specifying performance criteria are highlighted. A description of current testing procedures, including an overview of æquantitativeÆ design recommendations provided from various international authorities, is provided. A summary of international recommendations on suitable æqualitativeÆ performance classifications is also reviewed, including a critique of their suitability. Finally recommendations on the practical considerations necessary to ensure good quality, in-place SFRS, are made, including a calculation method for determining minimum steel fibre dosages.

Jan 1, 1999