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By L C. Thompson

A new understanding of the formation of black organic shales in the Illinois Basin has contributed to insights on how to produce methane from these complex reservoirs. These shales are far from simple shallow derived sediments but are in fact the result of a complex series of events which include the intermixing of volcanic detritus and the marine organic material, onlap successions and low energy turbiditic intraformational activity. This has led to a review of the commercial significance of the mid Devonian shales in the sedimentary basins of the eastern half of the USA. These shale sequences are also characterised by very little contribution from the underlying Lower Palaeozoic carbonate formations. The later diagenetic influences and the interaction of sea floor bacteria especially since the mid Devonian have lead to the creation of a major source of energy in the form of methane. Vast areas measured in 1000s of square kilometres are known to contain biogenically derived natural gas as methane. However, this vast resource produces very little gas due to abundance of illite which acts as a major adsorption mineral and creates a refractory situation where though there is abundant gas present the rate of release is clearly subeconomic. This paper will present the results of recent laboratory trials which have indicated that it is possible to create microfracturing using bacteria within the gas bearing shale sequence and also restart the methanogenesis process. As most coal bed methane environments have similar organically derived shales in direct relationship to the coal beds themselves then this paper has ramifications for this industry as well.

Jan 1, 2004

By Lightfoot BW, Foo KA, Conochie DS

Aberfoyle Limited operated a matte fuming pilot plant, incorporating a SIROSMELT furnace in 1980/81. This plant was a significant advance in both smelting and tin extraction technology. Important design, construction and commissioning aspects are discussed and some of the key points to emerge from this phase of the work are reviewed.

Jan 1, 1984

There is very little in Australian mining law that sets out the rights of mining tenement and exploration licence holders as against other parties who wish to carry out ground or aerial surveillance over those areas.There have already been several legal actions arising out of this lack, and more can be expected as the public places more rigorous constraints on corporate and individual behaviour. Field personnel, who are mainly fairly junior and less experienced, are entitled to some guidance from the minerals industry, guidance which up to now appears to have been either lacking or covering such a wide range of standards from corporation to corporation as to be virtually useless.Because each State writes its own laws there is no consistency, and the laws generally are lagging behind developments in the industry. In particular, the practice of granting mining tenements for sporadic exploration, a practice that is a leftover from much earlier mining law, has dotted the Australian continent with unattended and unmarked or poorly marked tenements that are difficult to find but confer on the holder prior rights to the minerals under them. Entry onto those areas in most jurisdictions is an offence and their existence compromises the efforts of regional explorers.This clearly unsatisfactory situation requires remedying, which is the purpose of these proposals. A more systematic approach to the granting of reconnaissance, regional and detailed exploration, mining, and retention rights will eliminate much of the problem. For the rest, a code of practice needs to be adopted as soon as possible.

Jan 1, 1996

By R L. Koenig

Previous papers at Metplant conferences have covered the options for crushing and grinding circuit selection. High Pressure Grinding Rolls (HPGR) may have considerable advantages over autogenous milling circuits but test work and evaluating different grinding circuits must be done to establish which circuit provides the best option. The Hawsons low grade magnetite project provides a specific example in using thorough test work, careful simulations and detail in design to allow the evaluation of grinding circuit performance. Fortunately tools are available for this evaluation and the test work for the Hawsons iron ore is detailed in this paper. The results of the test work and simulation indicates that although the Hawsons iron ore is competent in terms of autogenous milling given the medium hardness of the ore in the Drop Tests, the HPGR testing indicates that the use of HPGR is likely to use half the energy requirement. This is a characteristic of the Hawsons iron ore and is likely to be valid for other iron ores in the Braemer Iron Formation which stretches from the Hawsons lease in New South Wales to Razor Back and South Dam in South Australia. The Hawsons magnetite iron ore resource has been known from the early 1960s when CRA explored the area. However, the Pilbara region was discovered in this era and this led to development of high grade direct shipping grade hematite ores. Carpentaria Exploration (Capex) rediscovered the magnetite whilst undertaking multi-commodity exploration in the Broken Hill district during 2009. The magnetite grade was found to be low at around 16% Davis Tube mass recovery (DTR) but despite this, the project provides a positive business case as a result of the following key factors:• The mineralisation is particularly soft for crushing and grinding with a Bond Work Index of 6.3.• The mineralised rock fractures easily preferentially along grain boundaries.• The location is close to mining infrastructure and a skilled workforce in Broken Hill, 60km to the North East.• It is close to road and rail infrastructure for access to the resource.• The only contaminant in concentrate is silica.• The resource contains many billions of tonnes of magnetite mineralisation.The low Bond Work index is a key characteristic of the Hawsons iron ore and the use of autogenous milling and HPGR circuits is compared to other iron ores indicating why the plant energy requirement may be just as important as iron ore grades.

Aug 8, 2011

By T GRAHAM-TAYLOR

A trend towards mining more complex and economically marginal orebodies, often combined with increasingly tight product specifications, increases the number of variables which need to be considered in production scheduling. Linear programming incorporating integer constraints can be used to create production schedules which are practical as well as mathematically optimum. Factors which can be taken into account include variability in product stockpiles, targets for head or product grades, production of different material types, production from different areas, production targets for loaders, and dependencies between mining blocks. For each schedule an appropriate objective for optimisation must be chosen. Examples of objectives are: to minimise or maximise grade variation; to minimise waste movement; and to minimise movement by front end loaders. A staged approach to the implementation of computer systems based on linear programming optimisation is Proposed.

Jan 1, 1992

By Tsuchida N

The history of world nickel production has been affected significantly by the supply and demand situation and fluctuation of LME price of nickel metal. In the beginning of the 1980s, the decline of price and demand lead to the withdrawal of un-competitive producers and the shrinkage of the production capacity. During the same period, Sumitomo Metal Mining maintained the production level with continuous improvement of the traditional matte electrorefining process. However, Sumitomo has recognised that the continuous improvement alone does not promise us the ability to catch up with rapid changes in the world. In the meantime, Sumitomo intensively researched chloride hydrometallurgy and has developed the chloride process for the nickel refining. This includes the solvent extraction and chloride electrowinning in the mixed sulphide process and the chlorine leach of the anode slime arising from matte electrorefining. In the late-1980s, Sumitomo Metal Mining decided to develop a new nickel refining technology based on chloride hydrometallurgy. The new process was designed from the comprehensive aspects involving safety and the environment. Construction of the plant for the matte chlorine leach electrowinning (MCLE) process was commenced in 1991. The MCLE plant with a capacity to 2000 tonnes per month has been commissioned at Niihama since 1992. The process has provided high productivity, overall good economics and high quality of electrolytic nickel produced. After the establishment of the process, Sumitomo has maintained continuous improvement of the new process and has attained the best practice of the work classification.

Jan 1, 1996

In the last eight years inclined conveyor haulage systems have established themselves in the mainstream for hard rock underground mine haulage. This leaves the question; what else might be on the horizon for mine haulage and how do we address the process of selecting haulage systems for new mines? This paper considers the identification of viable haulage technologies for underground mines and explores an approach for assessing existing and potential technologies. The example of a large deep mine is considered here. The evaluation of existing haulage systems relies on precedence and the assessment of the system capacity to meet the haulage requirements envisaged for a particular mining project. The assessment of potential technologies for mine haulage relies on the capacity to deliver a viable production-scale system within the timeline envisaged for developing a mining project. The haulage technologies addressed in this paper include: shaft hoisting,conveyor haulage,truck haulage,vertical conveyors, andhydraulic hoisting. This paper does not consider rail haulage out of a mine. This is simply because Australian topography typically has insufficient relief to bring them into consideration. However, rail haulage is a widely used and effective haulage solution in situations where significant topographical relief is present. The assessment of haulage system capability focuses on the following fundamental questions: How reliable are they? What is the degree of technical risk in a business context?What levels of flexibility do they offer?How capital effective are they? What returns are indicated by the balance of capital and operating cost estimates?

Jan 1, 2008

When a fire or explosion occurs underground the ventilation maybe disrupted and the atmos- phere may become oxygen deficient and filled with noxious and flammable gases. The basic survival technique for:any man alive underground is to escape and this may be achieved and rescue workers may enter such atmospheres to carry out rescue work underground by using appropriate breathing apparatus.

Jan 1, 1983

The control of industrial grinding circuits in Australian concentrators has been practised for many years in one form or another. Some have established simple feedback loops in areas such as fine ore bin feeders (tonnage control), mill pump sump levels (flow control) and water additions (density control). There are also some sophisticated systems which infer circuit product size using complex measurements of mass flaws and water additions in the circuit and attempts are made to control those flaws to produce a constant circuit product size. The inferred size method in Australian concentrators has become firmly entrenched in the last ten years and control techniques involving the use of direct size measurements with reliable on-stream sizers have been Ignored.

Jan 1, 1983

By D A. Williams

The conventional method of transporting mine tailings from a process plant to a tailings storage facility (TSF) is in the form of a low to medium density1 slurry, which can be pumped using centrifugal pumps. Over the past several decades, therefore, mine operators have generally adopted this default approach. There are, however, some convincing arguments why consideration should be given to thickening the tailings slurry to a higher density paste consistency. In particular, the minimisation of environmental impacts, the reduction in water consumption and the cost savings relating to TSF closure make paste an attractive option for the life of mine tailings disposal. There are several environmental impacts that are associated with a conventional slurry TSF, such as land sterilisation, aesthetics, dust, seepage and acid mine drainage. Some of these impacts, such as dusting, may be difficult to mitigate while the TSF is in operation. Others can be influenced by adjustments made to the tailings slurry density at the plant. Unplanned fluctuations in slurry density and/or viscosity can have a significant influence on TSF performance and can exacerbate the environmental impacts relating to the facility. Relatively minor changes in the solids content of the slurry can affect tailings beaching behaviour, degree of segregation, position of the phreatic surface, amount of freeboard, consolidation behaviour, placed (settled) density (and hence TSF capacity) and in situ strength of the tailings. Paste is a non segregating slurry and many of these effects can be minimised at the TSF when the tailings slurry is thickened to a paste. These improvements are manifested by reduced seepage, flexibility in selecting an appropriate final landform, ability to rehabilitate progressively and reductions in plant water usage. It is possible to minimise environmental impacts of a TSF through the use of tailings paste. Ideally the paste production plant should be part of the initial design of the process plant. However, significant benefits can be gained by adding a paste production plant at some time later in the operational life of the mine to reduce environmental impacts and facilitate an environmentally acceptable TSF closure.

Jan 1, 2002

By I Sheppard, A Hills

This paper describes a multi-lift bench stoping method introduced recently to extract the narrow silver-lead-zinc orebodies at the Isa Lead Mine. Cut-and-fill methods were chief mining methods for the narrow orebodies at the mine over 35 years ago. Benching methods were introduced approximately two decades later, and quickly replacing the cut-and-fill methods. The benching methods had improved both the economy scale and safety of the mining operation. The multi-lift benching method combines a number of bench lifts into a single stope to further improve the operational efficiency. Three stopes in the initial multi-lift benching trials are described.

Jan 1, 2003

I trust you know now or will know by the time you havecompleted your degree and added a little on-the-job experience,how to make the product from the mine you are working for. Butyou may not know the process to turn it into dollars, which ofcourse will be the life blood of your company. I am not going topromise to turn you into super salesmen, but I hope I can takeyou beyond the level of believing that selling our mineralproducts is as simple as putting in it on to a train, waving itgoodbye and waiting for the cheque to turn up in the mailbox afew weeks later.

Jan 1, 1994

The Bowen Basin coal field is an important energy resource. A relatively small proportion is avail- able by open cut operations. Responsible men throughout the world have warned of the need to increase coal research immediately. Because energy is still available in abundance these warnings have not been heeded in Australia. The characteristics of the Bowen Basin coal make it a fairly difficult underground mining proposition and a significant research effort is required to solve the problems likely to be encountered. Both industry and government have responsibilities in the economic recovery of the maximum proportion of the resource and jointly funded research administered by existing organisations should be inaugurated forthwith.

Jan 1, 1976

By Johnston S

A blending trial was conducted on 60 per cent Perseverance/40 per cent Rockys Reward underground ore at WMC Resources Leinster Nickel Operations to compare the benefits between batching and blending treatment of the two ore sources. Milling, f

Jan 1, 1997

Taxes have an impact on mineral resource availability in several ways. There is the obvious effect on the grades needed for mineral deposits to become economic orebodies. There are also indirect effects which can have equally significant impacts. The paper examines the appropriateness of different types of taxes in the mining industry. The effects of discriminatory taxes such as price-based royalties are described. There is a discussion on the feasibility of introducing a single resources tax to replace completely the various forms of taxes presently applied to the industry. The subtle impacts of taxes are described in a section covering the way in which apprehension over future possible changes to both the level and diversity of taxes is reflected in industry confidence. It is concluded that taxation can significantly limit the economic availability of mineral resources.

Jan 1, 1978

Potential hlghwaJl mining reserves in Australia are large, but geotechnical and operating conditions are quite different from those where highwall mining has evolved in the USA. In order to achieve safe and effective resource recovery, equipment and procedures should be developed to penetrate 250 m in the Australian mining environment. This paper identifies key auributes to be incorporated in such machinery and methodology. These suggestions are intended to promote discussion on innovations to satisfy Australian requirements for highly productive, safe and environmentally acceptable techniques.

Jan 1, 1993

Although a formal EES was not prepared for the WIM project due it winding down, CRA Ltd has been through the EES and planning scheme amendment process for its demonstration plant. Community consultation was involved with all aspects of this process. The paper outlines the WIM EES consultation program and provides lessons for future community consultation for major projects in regional locations with significant potential to alter the environment.

Jan 1, 1992

By Draper J. J, Lang S. C

Regional geological mapping and facies analysis of the Late Devonian to Early Carboniferous Keelbottom Group of the Burdekin Basin have resulted in a depositional model representing six siliciclastic-carbonate facies. The six facies represent alluvial fan, braidplain delta, siliciclastic shoreline, siliciclastic shallow marine, restricted siliciclastic/carbonate shelf, and carbonate shoal depositional environments. These facies are identified in the Star beds which are equated with and included in the Keelbottom Group in this paper. Facies are repeated throughout the Group, as a result of two transgressive-regressive cycles.The first transgression recognised in the Keelbottom Group began in the mid-Famennian, and followed deposition of the Late Devonian Dotswood Group. It was marked by the deposition of Siliciclastic Shoreline facies in the basal Myrtlevale Formation, which was succeeded by Siliciclastic Shallow Marine facies at the peak of the transgression. The return of Siliciclastic Shoreline facies in the upper part of the Myrtlevale Formation marked the onset of the first regression, which resulted in the progradation of Braidplain Delta facies from the northwest of the basin. During the peak of this regression, deposition in the western part of the basin was dominated by Alluvial Fan facies.

Jan 1, 1990

By Eddy B. W, Washusen J. A, Wulff R. T

The State Electricity Commission of Victoria (SECV) has been con- tinuously involved in the extraction of brown coal from open cut mines in Victoria's Latrobe Valley for over 60 years, but have not completed a major mine. Detailed consideration for rehabilitation at this stage has only been able to be given to overburden disposal areas. Increasing interest in rehabilitation in the 1980's led the SECV to review its existing policies and practices and to embark in 1985 on a public consultation process to establish an agreed and accepted policy. This was extended in 1986 to the consultation process for the rehabilitation planning for the Mor- well Open Cut External Overburden Dump. This paper covers the con- sultative process developed and the lessons learned by the participants.

Jan 1, 1989

By Manula C. B

The total systems model for underground oal mining planning and design is a set of omputer programs which encompasses a realis- ic reproduction of the interaction between he geological, environmental, equipment, meth- ds and the health and safety aspects of the ining plan. The total system includes nine ajor subsystems - Geology and Reserves, Meth- ne Generator, Roof Support, Subsidence, Pro- uction, Rail Haulage, Cost, Water Generator, nd Ventilation. The subsystems themselves re divided into two categories based on the requency with which they are executed. Event riented Subsystems are executed either inde- endently, or at discrete intervals when cer- tain specific events occur. Dynamic subsystems 'unction interactively during the production :ycle. They transfer data to or request data `rom event oriented subsystems only when spe- ific events occur. Three specific areas for iodel application are in the measurement of system performance, the development of the '_ nterrelationships of the components of deep Wining process and the evaluation of new and Lnnovative mining technology.

Jan 1, 1977