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By Kurzeme M, Willoughby D. R

The current approach to the design of fill, as a structural component in a mining system, is based on traditional usage, previous experience, empirical rules and preconceived ideas. This approach does not permit the relative economicsof the various possibilities to be evaluated, retards introduction of new materials or processes, and results in fragmented fill research effort.A rational approach to the design of fill is proposed as a means of overcoming these disadvantages.This is based on five components:(a) statement of functions of fill,(b) definition of modes of fill response,(c) criteria of satisfactory performance,(d) analysis of fill response,(e) specification of required fill properties and methods of obtaining them.An assessment of each component indicates that the adoption of this rational design approach will require research effort in categorising modes of fill response and in defining criteria of satisfactory performance.

Jan 1, 1973

Currently, mining in Australia underpins the economic vitality of the nation, generating massive revenue from commodity exports and providing substantial infrastructure and employment. In addition, it is predicted that mining related services will in the future develop a global market of their own that could eventually grow to rival, in value, the export trade in mineral commodities. There is however little room for complacency. In the short- to medium-term, escalating, vigorous competition can be expected from many previously underdeveloped countries that are reforming their own mining and mineral export industries. In addition, most mining companies are facing a modem-day renaissance in terms of new expectations, changing social norms, evolving employee relations and statutory obligations. Thus, along with whatever promise the future might hold, the mining industry is currently being subjected to a growing number of largely unprecedented problems and pressures, both economic and social, that are both highly complex and demanding. In particular, it remains a matter of on-going concern that relations between mining companies and their employees still, in spite of recent reforms, continue to constrain productivity, perpetuate inefficiencies, affect quality of work life and retard progress towards mutually beneficial goals and achievements. If mining in Australia is to attain and hold on to a commanding position on the global scene, then further changes will clearly need to be made. Realisation of this appears to be growing, with most mining companies having attempted in recent years to improve workplace culture. Based on a wide ranging study, this paper presents an overview of what has been learned to-date with regard to the `people factor' when it comes to implementing and progressing positive change and reform in mining. From this, a number of practical suggestions, arising from hard won lessons and experiences in the field, are offered. Attention to the nine `key principles' given should help to ensure that many of the common problems encountered to-date with change and reform in the mining industry are in future avoided or at least minimised.

Jan 1, 1997

By Shonhardt JA, Bagster DF

This paper firstly examines the pollu- tion potential of burning colliery wastes. A comparison of two means of estimating the pro- pensity for coal to combust spontaneously is next presented. The use of microwaves, as a new procedure, is discussed in detail, while a comparison of the results is made with a modi- fied adiabatic technique. A number of coals that are known to combust spontaneously was tested, as were some coals that are not consi- dered to have self heating potential.

Jan 1, 1987

Leichhardt Colliery is developed for underground mining of coal seams at depths exceeding 280 m. Investigations of the area were conducted in phases, each designed to delineate seam characteristics more accurately and to indicate with increasing precision the nature of local geological features and the ranges of those coal properties susceptible to variation. The investigational campaign is described phase by phase summarizing evaluation of the area at the conclusion of each phase. Predictions of geological conditions likely to influence engineering planning are contrasted with actual conditions observed during trial mining.

Jan 1, 1974

In coal room and pillar, and pillar extraction panels, the sidewall conditions were investigated based on underground measurements and numerical simulations. Three-dimensional linear elastic models provided a useful and quick prediction of the amount of sidewall spalling. However, more complex constitutive models were required to simulate more accurately the extent of fracturing and its effect on the stress re-distribution. The input parameters of a Mohr-Coulomb model were determined by back-analysis of underground measurements, and the effect of the depth of the workings and the time dependent occcurrence of coal pillar fracturing were analyzed.

Jan 1, 1992

By J Wei, X Lan, F Wang

This paper presents a quantitative assessment model for the assessment of environmental load in gold production, which is based on environmental ecology, Life Cycle Assessment (LCA) and artificial neural network. In LCA evaluation indexes include resource consumption, energy consumption, gas waste, liquid waste, solid waste and so on. Each item represents an aspect in gold production while their combination reflects the relationship between gold production and environment. In this paper an utility function of evolution index on environmental load is given by linear or non-linear transformation, which changes evaluation indexes with different dimension into an equivalent value in range of [-1, 1]. This paper also provides a new approach to make decision on the weight for quantitative assessment with the help of a three-layered artificial neural network. The proposed approach in this paper has been successfully used to a real synthetic assessment for the environmental load in gold production, which include seven kinds of different operational technologies in China. The applications prove that the new approach is successful and reliable. It provides a new tool for the assessment of environmental load of the gold production.

Jan 1, 2003

The eastern Asia island-arc systems are regarded as specific marginal structures having the common features of geological development and deep structure. The notions on deep structure of island- arc systems are based on the data of studies of the mantle and low-crustal xenoliths. Analysis of location of deposits and ore occurrences of different ages within island arcs in comparison with, the processes of deep heat and mass transfer allows us to develop a-model of mobilization, migration and accumulation of ore substance in the "crust-mantle" system.

Jan 1, 1987

The effect of temperature, time and SO2 concentration in the atmosphate have been studied for a complex Pb-Zn concentrate, which contained four sulphides and some organic material, in order to determine optimum roasting conditions. Under static roasting conditions virtually complete sulphation was achieved after roasting at 650¦C.2 hours in 10% SO2 in air. Both zinc ferrite and zinc silicate were observed to form early in the roasting, but continued exposure to SO2 -containing gases caused decomposition of these as the roasting time increased. Water and acid solubilities of iron, silica, calcium, magnesium and aluminium in the calcine were determined, as a function of roasting time, temperature and atmosphere composition.

Jan 1, 1970

The geographical region of South East Asia is variously defined, but generally agreed to include the Asean group - Philippines, Malaysia, Thailand, Singapore and Indonesia. Other regional countries, such as Vietnam, Laos, Burma, Kampuchea etc. are of course geographically part of the region, however in economic terms, they play a minor role. It is the Asean group that dominates present economic activity and provides the overwhelming opportunity for commercial development. My experience in South East Asia has been gleaned over 15 years of regular travel in the region. More recently, we have established company offices in Malaysia, Singapore and Indonesia to extend and deepen contacts with major customers. This progressive development is an integral part of a planned growth pattern and will be discussed in more detail shortly. South East Asia is a rapidly developing economic growth centre, a fact which is clearly recognised and accepted by most commentators. An important question is then to be asked: Why has the region been relatively neglected by Australian, U.S. and European industrial supply companies? I will attempt to address this question in the context of industrial minerals and propose some ideas as to how effective sales programs could be developed. Firstly, let's consider the market potential provided by countries within the region. It is reasonable to suggest that industrial growth in S.E. Asia over the past 20 years has been generally steady and in some cases, explosive. Until recently, this growth has predominantly been driven by development of internal (regional) demand. Population growth and rising living standards have ensured that basic industries have enjoyed a solid uptrend in sales and production. The industries which most benefitted from regional economic development over this period were, interestingly, those which we understand to be major users of industrial minerals - glass, ceramics, paper, surface coatings, cement, refractories, rubber and plastics. Each of these industrial sectors has been influenced by different growth stimulii over a 20 year period. Nevertheless, they also enjoy a common feature which ensured an above average performance. All sectors are fundamental to an environment enjoying rising living standards and rapid growth in general prosperity. More recently, internal growth factors have been overtaken by a recognition that manufactured products from the region are competitive in export markets. This comparatively recent development provides the most interesting possibilities for higher value industrial mineral raw materials. Let me explain: For 20 years, industrial growth in South Asia has essentially been focused on satisfying domestic demand. Finished quality of manufactured items was orientated to a developing market more interested in cost than aesthetics or long life. This was reflected in raw material specifications, which often did not exist and at the best were undemanding.

Jan 1, 1989

By P C. Hagan

Production scheduling is often reliant on an estimation of a mineÆs trucking capacity. While this mechanistic approach is relatively simple, it often over-estimates actual throughput resulting in under-utilisation of downstream process and a shortfall in revenue. An alternate approach has been developed that recognises the interdependency between processes in the mine production system including materials loading, haulage and crushing. This approach incorporates a heuristic model based on queuing theory that accounts for the variability in performance of individual processes and that this paper presents the results of a study comparing the conventional approach to mine scheduling with a capacity constrained model at a large open cut mine having a truck and shovel fleet. The capacity constrained model consistently predicted a lower material throughput compared to the conventional approach. Differences in throughput between the two approaches were found to increase with loading time, for example when loading time exceeded 3.9 minutes there was a shortfall of up to 40 per cent in estimated throughput. Longer travel times tended to ameliorate any differences. When applied to a mine schedule that extended over a two and a half year period, the difference was equivalent to a shortfall of nearly eight per cent in total material movement.

Jan 1, 2007

Agglomeration pre-treatment is a new process now being used here and overseas whereby problems arising with the heap leaching of gold and silver from materials containing critical amounts of fines or clay can be simply and cheaply overcome. The technique involves mixing the material with a suitable binder, commonly Portland Cement, and tumbling the moistened material to agglomerate the fines. These agglomerates are placed on the leach pad and cured prior to leaching. Test results, plant and operating cost data are presented. INTRODUCTION Heap leaching is a low capital and operating cost alternative to conven tional processing techniques for gold and silver extraction. A number of commercial-scale operations have recently started in the United States and the method is being considered for further deposits there and elsewhere.

Jan 1, 1982

By Nightingale RJ

A column (50 cm 4) provided with a bell charging mechanism and a rectangular perspex insert was used to investigate the inter-relationship between charging pattern, size analysis and velocity profile for a number of charging methods. It is shown that a strong correspondence exists between size distribution and velocity profile for bell charged ore and coke and that decreased coke volumes cause higher pressure drops and increased central flow in beds with "V" shaped layers. It is also shown that a bell charged mixed burden exhibits greater segregation than when it is bell charged as layers and that when uniformly charged the mixed burden shows least segregation and a virtually flat velocity profile. A relationship is derived for "V" profile charges showing the extent of central segregation with furnace size.

Jan 1, 1975

I am very grateful to have the honor of delivering this Key- note Speech to all of you here today, to the Chairman Mr Cope- man, and to all the organisers. As you heard, I was mainly involved for a very long time in the purchase of iron and steel raw materials for Nippon Steel Corporation. Today, however, I would like to talk to you about a much wider issue, namely, how the Japanese steel industry is going to change towards the 21st Century, and what will be the main technical innovations and trends behind those changes. I will also mention the effect that the changes are likely to have on the procurement of raw Materials.

Jan 1, 1988

By L Lorenzen, C Aldrich

In this paper, a neurofuzzy model is proposed for the development of an explanatory model of an industrial gold leach circuit based on historic plant data. A regression tree was used to partition the data in the predictor variable space and the structure of the tree was used as a basis for the derivation of fuzzy rules that could be integrated into a fuzzy expert system useful for operator decision support or process control. The position and shape of the membership functions were optimised with a backpropagation algorithm in a neural network framework. The approach yielded a significantly better explanatory model of the gold losses in the plant than comparable linear models. Although a regression tree could perform somewhat better in accounting for the variance of the dissolved gold losses, the tree was less robust than the fuzzy model.

Jan 1, 2007

Concrete has been used for many years in block caving, principally for drift and drawpoint linings. This paper describes the requirements for concrete in this application, the required properties, the mix design, and transportation and placement systems. In addition a concrete mix design rationale is also proposed.

Jan 1, 2000

By P J. Mathew

Quality and process control in the iron ore industry is based on measurements of ore grade from blast holes through to shiploading. Traditionally this has been carried out using conventional sampling, sample preparation and analysis methods, but on-line analysers are now being introduced for monitoring the grade of important process streams. Once a conventional sample has been collected, it can be analysed for a wide range of elements. On the other hand, on-line analysers measure only a few selected elements, but they provide rapid feedback on grade, which is important for effective quality and process control. In both cases, the linkage between mining, processing and final blending operations at the port is crucial to ensuring that product quality is maintained while production targets are met and the life of the resource is maximised.

Jan 1, 1998

The impact of moves to introduce Abori- ginal land rights was felt in the Northern Territory as early as 1972 when the Federal Government froze the processing of all appli- cations for mining interests over vacant Crown land. The Aboriginal Land Rights (Northern Territory) Act was finally proclaimed on Aust- ralia Day 1977 and since that date the mining industry and the Territory legislature have struggled to make the Act work. Despite these efforts long delays have been experienced by those required to negotiate mining and explor- ation agreements under the Act. In fact explor- ation on Aboriginal land has been effectively stiffled since the introduction of the Abori- ginal Land Rights Act. The Northern Territory government and the mining industry have both sought amendment to the Act to remedy some of its more onerous problems. These efforts have generally been fruitless. Some of the recommendations put forward by Mr Justice Toohey following his recent review of the Act would provide relief in some important areas. However, any such improvements are more than offset by a number of Mr Justice Toohey's recommendations which would severely disadvantage the vast majority of Territorians. A recent survey of mining companies seeking exploration licences over Aboriginal land indicates that many of the existing diffi- culties could be overcome without significant amendment to the Act but rather by the adoption of a positive administrative approach by the Land Councils. It is now up to the Commonwealth and the Land Councils to demonstrate that their Act can work without crippling the Northern Territory economy and its mining industry.

Jan 1, 1984

In February 1974 a continuous synthetic polymer dosing plant was installed at Hamersley Iron Pty. Limited's Pellet Plant at Dampier. The polymer, supplied in a liquid sus- pension, is used to improve the drying characteristics of green pellets. 'Three years of test work were involved in the development of the use of polymers. Polymer is continuously dosed to the balling spray water system at a rate determined by the flow of spray water to the discs. Problems have been experienced with handling the polymer in 44 gallon drums, the increased viscosity of the spray water, disc overloads, increased bed strength and increased "stickiness" of pellet fines.

Jan 1, 1974

Mine site restoration, involving the re-establishment of original ecosystems, is a far greater challenge than revegetation, which simply aims to stabilise the site and to give it a green appearance. One of the challenges is to establish a simple yet effective measure of restoration success. A potentially useful approach is to focus on particular groups of plants or animals which are likely to provide a general indication of the state of the ecosystem in which they occur. Ants have been used extensively by the mining industry in this context, particularly in northern Australia. Ants are likely to be useful bioindicators because of their general importance in the Australian environment, and because of the many linkages they have with other parts of the ecosystem. Moreover, ant community structure responds to stress and disturbance in predictable ways, and therefore provides an interpretable measure of ecosystem change. This is illustrated by a study of ant recolonisation at Ranger uranium mine. However, the extent to which ants reflect the responses of other ecosystem components is poorly documented. This is currently the subject of a collaborative project between OSS and CSIRO.

Jan 1, 1994

Economic evaluations of mineral projects are based on discounted cash flow analyses, followed by sensitivity and risk analyses. However, the global macroeconomic and political environment in which the mineral industries operate have a profound effect on the viability of individual projects. Since the oil crises of 1974 and 1980, demand patterns for minerals have become much more variable and prices more volatile. Significant changes in the geographical distribution of world mineral supply and demand are underway, and the mix of minerals used is also changing. Social and political factors are as important as economic and technical factors in determining the viability of mineral ventures. Economic evaluation of mineral projects have to be undertaken in a more uncertain and risky environment. They can no longer be reduced to a number crunching exercise.

Jan 1, 1987