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By R G Warren

Sparse geochronological data have been combined with data on felsic suites and depositional facies of rocks to provide an overview of the development of the Arunta Block. The study provides a basis for construction of a map showing the distribution of granites and associated felsic extrusive rocks in the Anmta Block. The tectonic evolution can be subdivided into a series of significant time intervals. Only in the initial stage, to about 1880 Ma, was there any subduction-related magmatism. All later felsic magmas were crustal-derived melts. The early, pre-1880 Ma arc-related units in the SE contain small showings of Cu, probably including the small Cu deposit in the Casey Bore Inlier at the edge of the Simpson Desert. The most significant time-interval for formation of mineral deposits was 1820-1760 Ma, when volcanogenic Cu-Pb-Zn deposits formed in the Strangways Metamorphic Complex and also in the Jervois district. Stratabound tungsten lodes in the hanging wall of

Jan 1, 1994

By G R. Hancock, J F. Martín Duque

Post-mining landscapes are required to geomorphologically and ecologically integrate with their surrounds (Martín Duque et al., 2015). Designing and constructing an erosionally stable landform is the first and arguably most important part of the rehabilitation process. Without an erosionally stable landform topsoil and nutrients are lost, shallow groundwater is depleted as well as when excessive erosion occurs, expose suboptimal materials. Here we examine the ideas of geomorphic design and rehabilitation and how the landform can be tested and enhanced using computer based design and landscape evolution models. Specifically we evaluate the complementary capabilities of landscape modelling (SIBERIA) (Hancock and Willgoose, 2017) and geomorphic design software (Natural Regrade with GeoFluv) (Bugosh et al., 2016), in order to maximise erosional stability on post-mining landscapes (Zapico et al., 2018). CITATION:Hancock, G R and Martín Duque, J F, 2018. Geomorphic design and landscape evolution modelling for best practice mine rehabilitation, in Proceedings Life-of-Mine 2018, pp 119–121 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By E Baafi, G Brassington

Coal mining operations can impact on various types of surface infrastructure or natural features, including cliff-lines, steep slopes and natural watercourses. Longwall mining leads to a subsidence depression due to the changing geometry of the mined out area. The current regulatory process for managing subsidence in New South Wales (NSW) involves the preparation of a Subsidence Management Plan (SMP). This paper demonstrates the use of a Weights of Evidence (WofE) technique applied within a Geographical Information Systems (GIS) environment to predict potential areas for rockfalls along cliff-lines in the NSW Southern Coalfield. The WofE is a ædata-drivenÆ method that can be used to predict subsidence impacts prior to mining. The WofE method was applied to ten known rockfalls along the Cataract River to evaluate the reduced impact of not mining within 50 m of cliff-lines along the Nepean River. There is significant reduction of probabilities of rockfall occurrence when mining is avoided within 50 m of cliffs.

Jan 1, 2006

By P Vaikkattil, K Li, J Bullock

Unlocking maximum value is essential when designing a stope and the associated drill and blast packets. This is becoming increasingly important at Olympic Dam as the operation continues to expand south into the new mining areas away from existing infrastructure, increasing operating costs and required capital investment; into areas with less competent ground conditions, requiring smaller stopes and increased interactions. The introduction of Orica’s WebGenTM system is one way in which Olympic Dam can continue to unlock value into the future by decoupling traditional drill and blast limitations. The Lime 390 stope was the first stope at Olympic Dam to trial the new technology on the last blast packet. This paper reviews the drill and blast design of the Lime 390 stope, including the technical and operational challenges associated with the stope and the trial of the Orica’s WebGenTM system for the firing of the last blast packet.

Mar 15, 2021

Attention is given to three possible alternative structures namely corporate joint venture, partnership joint venture and unincorporated joint venture. A corporate joint venture involves the formation of a separate and distinct legal entity with limited liability. The shareholders of the Company will be the members of the consortium. A partnership joint venture involves the members of the consortium joining a formal partnership. The partners will conduct the business in common with each other and will share the profits and losses of the project activities. The partners will be jointly and severally liable. An unincorporated joint venture is distinct from a partnership. The members of the venture will not be jointly and severally liable. Taxation and accounting aspects are examined and an outline provided of a typical joint venture agreement. The two main advantages of an unincorporated joint venture are considered to be a favourable treatment for income tax purposes and a greater degree of flexibility when compared with the corporate joint venture and the partnership joint venture.

Jan 1, 1983

The blasting of the 2190_6095 stope at Kimberley Nickel MineÆs Sally Malay operation in Western Australia is an example of what can be achieved with electronic detonating systems when a drill and blast engineering team is faced with complex blast geometry and a major pump station in close proximity to the stope. Using Dyno NobelÆs HotShotÖ system, the engineering team successfully designed and initiated the 36.5 Kt stope firing, with a powder factor of 0.35, resulting in no damage to the pump infrastructure, better fragmentation of the ore and less overbreak in what had previously been a geotechnical and geometrically challenging stoping environment. This paper will discuss the design parameters used for this stope blast as well as the benefits the operation found in using precision detonator timing in this 252 hole shot over two levels using a combination of up and down and slashing rings that were initiated in four different directions.

Jan 1, 2007

By Trevits MA

The United States Steel Corp. in cooperation with the United States Government is conducting a large-scale methane drainage field demonstration using stimulated vertical boreholes drilled in advance of mining. A grid pattern of 23 boreholes, isolating approximately 1.5 km2 of coalbed area, has been drilled to the lower bench of the Mary Lee coalbed, Jefferson County, Alabama. Upon completion of drilling operations, various hydraulic stimulation treatments utilizing nitrogen-generated foam, water, and gelled fluid were performed to enhance the rate of methane gas removal. Production from the grid pattern began in September 1977 and continued as the last borehole was placed on production during October 1980. To date, in excess of 33,800,000 m3 of methane gas has been drained as a result of this effort. Underground mining operations were approximately 3.2 km from the grid pattern when production began and have currently progressed to within 1.6 km. Underground interception of the grid is expected in 1986.

Jan 1, 1982

This paper describes some experiences in the design of flotation reagent schemes for the efficient flotation of complex gold ores containing free gold and/or gold associated with easily flotable sulphide minerals such as chalcopyrite and bornite. Historically, the design of gold flotation reagent schemes has been based primarily on experiences using high dosage levels of water soluble charged collectors such as xanthates and dithiophosphates and carefully controlled regions of pH. This approach has been effective with gold associated with complex sulphide minerals, in particular gold associated with iron sulphides such as pyrite. An alternative two-stage reagent approach is presented that is applicable to certain types of gold ores. This approach involves using very small dosages of uncharged water insoluble collectors at natural ore pH followed by a modified bulk flotation reagent approach for the second stage. The reasons for utilising this approach, when applicable, are discussed and illustrated with examples.

Jan 1, 1997

By S Vianna

Mineralogical information obtained from plant surveys is subject to errors, both due to sampling and experiment. To reduce these errors, and to ensure that information is consistent, a data reconciliation model has been developed for mineralogical data. Its capability includes mass balancing size data, total assays, assays within size-classes and liberation data. Unlike any other mass balance package, this package also allows reconciliation of the complex mineralogical information. For example, particles cannot simply be treated as binary, but consist of combinations of many minerals. Hence the distribution of mineralogical information is multidimensional and the mineralogical distributions are referred to as multiphase. In this paper, the different levels of mass balancing are explained, including how to mass balance liberation data. Furthermore a new technique based on probability theory can be used to infer distributions even when there is insufficient information to perform a mass balance, and this technique is also explained. Results for various stages are given.

Jan 1, 2002

Government geoscience may be categorised by objective under three headings: Applied Research for Geoscientific Framework Studies, Resource Inventory, and Technical Advice. In Queensland, the Department of Resource Industries is active in all three categories. Under the program-based management system adopted in 1987, three Programs, namely, Geological Survey, Mineral Resources Development, and Energy Resources Development and Utilisation, have geoscience responsibilities.Prime responsibility for geoscience resides with the Geological Survey Program, which provides a geoscientific framework for mineral and energy exploration and the development of the State. Simply stated, the Program goal is to provide geological information when and where it is required. Geological Survey work also encompasses aspects of resource inventory and technical advice, complementing the work of the other two Programs. This role has a 122 year long tradition, for geoscientists of the Geological Survey have been engaged in investigations designed to facilitate the identification and utilisation of the mineral, water and energy resources of Queensland since 1868.

Jan 1, 1990

By Bell MG

At various decision points in the development of a project, a developer, joint venture partner or financial institution may require an independent review of the basic assumptions and technical aspects of the project. This type of review or technical audit is becoming a more common feature of the project development process. This feature has evolved because of the need of investors and lenders to be more confident of the viability of a project by the confirmation of its technical and cost aspects. Technical Audits offset some uncertainties introduced by the combination of longer development periods for, projects and the highly dynamic world economic scene. This paper reviews the place, nature and process of the technical audit by examining the circumstances when it might be needed, the typical scope of work or brief, the responsibilities of and relationship between the auditor and the client, and the auditing procedure. Detailed aspects of technical audits are discussed followed by a case study of the Hail Creek Coal Project Audit.

Jan 1, 1983

By Morrison RD, Simmons CJ

A bewildering array of process control instrumentation is currently available for mineral processing plants. For sequencing control, special purpose microprocessors or the process control computer can be used. Where continuous control is required, then the choice is between pneumatic controllers, electronic controllers, shared display micro- processor systems and direct digital control. The benefits of each system are discussed and the advantages of using direct digital control in mineral processing plants are outlined. The factors which need to be considered when selecting control systems for new plants are listed. Instrumentation systems designed by Fluor Australia are used as case studies to illustrate the selection process. For established plants, conversion to direct digital can be advantageous, and case studies are given. However, replacement of existing systems requires justification based on a productivity improvement which will allow the control equipment to be paid for within a specific time period. Productivity improve- ments maybe assessed in terms of increased

Jan 1, 1978

All sections of our community are becoming increasingly aware of the dangers of uncontroll- ed erosion associated with modern earthworksy whether they be concerned with the protection of capital structures, reforestation of mine tailings or generally the aesthetic and ecol- ogical impact. Because of the many ecological variances and climatic conditions no single technique may be offered as the complete answer. Rather that a combination of a series of techniques is nec- essary to achieve an individual end result. These techniques may appear to be expensive initially, but when considered in relation to the overall cost, and we realise that this work represents our only insurance of the stability of our project, the cost of stabilisation is insignificant. Once erosion has commenced the cost of stabilisation escalates dramatically which highlights the definite need to include the requirement of stabilisation in early design of your projects. Stabilisation should commence during construction to ensure that control of mobile soils is gained at the earliest possible time.

Jan 1, 1976

By Fewings JH

When the mining and milling of 1100 Copper Orebody commenced, difficulties were experienced in producing a satisfactory grade of copper concentrate. The major concentrate contaminants were fine pyrite and silica, particularly in the minus 10 microns fraction. Studies of the 1100 Orebody showed that much of the fine grained pyrite and a proportion of the silica present in the ore contained carbonaceous matter in the form of complete or partial rims and as internal carbon films disseminated throughout grains. The hydrophobic surface property of the carbonaceous material resulted in an inherently flotable fine pyrite and silica fraction. The addition of a 60:40 mixture of nigrosine and dextrine, initially to a prefloat concentrate of the inherently flotable carbonaceous material and finally to'the total copper flotation feed, successfully controlled the flotation rates of the carbonaceous pyrite and silica. The objective of a 25 per cent Cu concentrate grade was then achieved without decreasing copper recovery.

Jan 1, 1970

Natural gas is a comparatively new fuel in Australia. It was first used in small quantities in Queensland in 1965, but it was not until 1969 that natural gas reached the capital cities Brisbane, Melbourne, and Adelaide in that order; then in 1971 it reached Perth. By the mid seventies, natural gas had secured a significant proportion of the energy markets in Queensland, Victoria, South Australia and Western Australia and in 1976 supply commenced in Sydney. In that year - 1976 - gas supplied about 12.5% of the total demand for primary energy in Australia excluding transport. In the current financial year - 1981/82 - natural gas is expected to supply nearly 19% of the market and forecasts for 1990 range up to 25%. From a starting point in the late 1960's when manufactured gas supplied a small but important proportion of the non-transport energy market - less than 3% - we have exper- ienced an average growth of nearly 24% per annum up to the present time.

Jan 1, 1982

A company tax rate based on profitability return, or as more commonly expressed, a resource rent taxation scheme has been intro- duced at various stages in the past by both Australian state and commonwealth governments. At present a number of overseas countries are applying this form of legislation to the taxing of sections of their mining industries. Within this study, ways in which this type of tax has been used are examined. The form in which the tax can be applied varies. 1. It can be selectively or universally applied. 2. The base on which economic return is calculated can be selected in a number of ways. 3. It can start operating only when high profit levels exist, or alternatively be the basis of a total taxation scheme. The implication for the Australian mining industry of the introduction of different types of resource rent taxation schemes is assessed within the context of previously enacted systems.

Jan 1, 1978

Financial theory often takes some time to penetrate industry and when it does it can result in a paradigm shift in valuations and mental models. The Black Scholes option valuation was first published in 1973, although the authors were only awarded a Nobel Prize in 1997. The valuation of real options has been applied to the oil and gas industry for some time, however it has only recently been more widely applied to the non-oil, mineral resource sector. The use of real option valuation (ROV) for the valuation of marginal and short mine life resource projects is a more useful valuation tool than the conventional DCF, NPV valuation tool. The application of ROV has major implications for corporate strategy. It generally favours equity over debt funding and non-hedging over hedging. A retrospective assessment of the successful development of the Lennard Shelf Operations demonstrates the concepts of implementing real options and the value destruction of limiting operational flexibility through debt and hedging activities.

Jan 1, 2003

By Kershaw MG

At the Risdon plant of the Electrolytic Zinc Company of Australasia Limited, impurities toxic to the electrolytic production of zinc metal, notably arsenic and antimony, have traditionally been coprecipitated when precipitating iron as ferric hydroxide. With the development of a new lead/zinc mine at Elura, New South Wales, it was anticipated that the concentration of impurities, particularly arsenic, in the zinc sulphide concentrates treated at Risdon would increase. This suggested that an increase in the capacity of the iron purification step in the Risdon plant would be required to cope with the higher input of these impurities.Laboratory investigations showed that the additional capacity would be achieved, either by a massive increase in the amount of iron used as the "collector" in the process, or by a two-stage process. The latter approach was preferred as an increase in the amount of iron precipitated would lead to much higher operating costs and overloading of the existing equipment.

Jan 1, 1985

The growth of the mining industry around Australia over the last ten years has seen many open cut mines developed on shallow oxide reserves. Most of these have been gold operations, although there are some copper mines in the list, too. Many of these have exhausted their oxide reserves and have made the transition to underground mining to access their deeper sulphide ores. Other operations have reached or are approaching the point where the decision has to be made to go underground or cease mining. This paper discusses the issues involved in making the transition from surface to underground mining. The aim is not to discuss each of the issues exhaustively. This would take a conference in its own right. Nor is it intended to provide a primer on underground mining. Instead the aim is, firstly, to flag the issues which must be addressed when planning to make the transition from surface to underground mining and, secondly, to identify critical aspects of mine development.

Jan 1, 1997

A mining joint venture presents a real management challenge to achieve harmony with the other participants in the successful development and operation of a mine. This can best be facilitated by a detailed agreement and guided by a set of joint venture principles which recognise the differences of the interests of the parties and seek to establish sound business and personal principles by which differences not anticipated in the agreement might be resolved. The major and minor co-venturers can and do present potential difficulties to one another. This paper, one of the pair in the joint venture panel discussion session, predominately presents the minor's viewpoint. Usually commercial matters such as project finance, areas of interest, divestment, pre-emptive rights and decision-making can be adequately covered in the agreement. However, when the parties disagree and have difficulty in resolving their differences, the joint venture principles should be used to advantage to resolve relationship difficulties.

Jan 1, 1997