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Obtaining correct assays for gold determinations relies on the correct methods being chosen and the assayer being made aware of the mineralogy of the sample and its general origin. Usually when a geologist or metallurgist obtains "incorrect" gold assays the problem can be traced to poor communication between the geologist or metallurgist and the assayer.

Jan 1, 1986

By Lin Bin, Minggao Qian, Zhiyi Yang, Fullan He

There are no efficient methods and instruments available in China at present for diagnosing the leakage problem for a hydraulic support system in underground coal mines. A new method has been developed to solve the problem. It is proposed that

Jan 1, 1998

By Summers DA

Faculty at the University of Missouri-Rolla have carried out research on the application of high pressure water jets as a means of excavat- ing coal for over 15 years. During the course of this time, a number of different concepts have been explored--the most recent of which has been to use high pressure water jets as a means of extinguishing an underground coal seam fire. This paper will examine the use of some of these technologies and will consider the results as a basis for discussion of further applications of water jets in the future. The structural pro- perties of coal which distinguish it from other adjacent geotechnical material and provide a considerable advantage to water jet cutting, will also be presented and the advantages of using this tool will be discussed.

Jan 1, 1986

In recent years, wide consideration has had to be given to methods of improving the condition of the mine environment in many coal mines, and significant developments and changes have evolved. Thus even after substantial increases inòair flow rates at the working place (they have increased over three fold in the last generation), environmental conditions have arisen for which it has been necessary to introduce or consider: i) additional ameliorative measures, such as good housekeeping; ii) layout changes: such as Y or Z layouts; iii) homotropal ventilation; and iv) air conditioning. In certain countries, consideration has been given also to: v) additional payments reduced working times; vi) heat acclimatisation programmes; and vii) the use of cold or cooling suits At many hot and humid mines, the principal benefits from adopting (i), (ii) and (iii) have already been realised. At such mines,

Jan 1, 1983

MAXIMINE is a compiled, comprehensive, spreadsheet-based, macro- driven software package, written to aid in the rapid and early assessment and design of virtually any small, medium, and large mining or quarrying project. The system has been des

Jan 1, 1998

The mining industry worldwide relies upon the identification of resources that can be economically developed and operated. Access to land is paramount through all stages of the exploration, development, operation and rehabilitation stages. Clear rights to use of land for the purposes of mining must be available and protected throughout the life of the project. Stable and enduring criteria for mining of the resource, once identified, are required to attract exploration and development expenditure. The purpose of this paper is to investigate the varying approaches to granting access to land for use for exploration and mining development, including the processes by which a project is approved by community and government and the time scale for such approval. The paper concentrates on the legal issues arising throughout this process. The law is stated as at September 1997.

Jan 1, 1997

Upon subduction, water is liberated from the sediments and the porous struc- ture of the oceanic crust and from de- hydration of minerals for redistribution and chemical reaction. A survey of pro- cesses which are likely to occur along the subducting plate reveals that water may well be basic in subduction induced gas generation, magma formation and ore deposition. In analogy to the industrial water gas process, reaction of water with car- bonaceous matter, in subducted sediments is likely to yield substantial volumes of hydrogen and carbon dioxide. While water and carbon dioxide appear to play a determining role in the development of differentiated magmas, hydrogen will react with metal sulfides and sulfur to form hydrogen sulfide which is essential in sulfide ore depo- sition. A survey of possible metal extrac- tion chemistry along subduction suggests a stepwise solubilization of metals from sediments and oceanic crust, and a poten tial accumulation of dissolved metals in zones of characteristic composition. The metal spectrum in ore deposits at near surface appears to reflect the com- position of the solution in the respec- tive subduction zone. A tendency for preferential solubi- lization of copper at subductidn level, from among the transition metals, an in- creasing generation of hydrogen sulfide in the sane direction and partition effects as well as sulfide precipitation characteristics lead to enrichment in copper and to its selective deposition in the direction towards the trench as observed in S. Latin America. A postscript deals with the formation of native copper.

Jan 1, 1986

Discovery 2000 is basically about data, its collection, management, assessment and dissemination. A major focus of Discovery 2000 is the collection of new geoscientific data. However, the Department is already a major source of data on the geology and mineral resources of New South Wales. These existing data when combined with the new data, will greatly enhance the knowledge of and information on the geology and the mineral development potential of New South Wales. This paper discusses some of the existing datasets and outlines how they can be accessed. It also gives an insight into the Department's strategy for data and information technology management.

Jan 1, 1995

By P G. Fuller

The Woodlawn Mine near Canberra faced the challenge of poor ground conditions from the commencement of underground operations 1987. Talcose shears bounded the dense massive sulphides on both the hangingwall and footwall side of the orebody. In another area the talc existed not only on the edges of the orebody but through out it as well. The country rock was relatively weak shales compounded by a low stress environment that allowed the wall rocks to fall apart quite easily. The challenge for the operators was to overcome the poor ground conditions. This was done by attacking the problem from three directions:technology, how technology is applied, human relations and leadership by all levels of the Management team, and by ensuring that these processes meshed together well.Woodlawn in it early days as an underground mine enlisted the assistance of BFP (Formerly Barrett Fuller and Partners) as a second set of eyes to assist with the assessment of the ground control procedures. The results are discussed in this paper. The progression to this end result included:non-contract payment systems; ground control training for the full range of mining personnel; the development and enhancement of cable bolting and shotcreting equipment; the development of Practical Standard Work Procedures by mine operators; and innovative use of shotcrete and cables bolts to control extremely poor ground conditions.

Jan 1, 1998

By K McCaffery, R P. Halomoan

Two column flotation cells have been installed as single-stage rougher cleaners at Batu Hijau. The objective was to provide additional residence time in the cleaner circuit to maintain maximum recovery during high mill throughput and high feed grade periods. Installation of the columns has allowed the relatively coarse, well-liberated rougher concentrate and the relatively fine, low-grade scavenger concentrate to be treated separately, improving metallurgical performance in the cleaner circuit. Plant results show that the columns produce a high-grade concentrate at an average stage copper recovery of approximately 80 per cent. There is also indication of increases in both overall plant copper recovery and final concentrate copper grade. In addition, the operability and stability of the cleaner circuit has greatly improved.

Jan 1, 2007

By P McCarthy

Despite significant advances in the platform technologies that could form part of a system of mine automation, the goal of full automation in most underground mining applications remains distant. This is because the industry developed these platform technologies to achieve local improvements in safety, machine and labour productivity, and asset utilisation, rather than to work towards a goal of a complete system of automation for general application in underground mines. This paper reviews the history and current state of automation in the underground mining industry and uses lessons learnt from the automobile and general manufacturing industries to gain insight into the opportunities and pitfalls in the complex and uncertain path to automation of underground mines. It also evaluates the relevance of the current drivers of interest in the industry. From this, we hope to engender an attainable vision of automation in underground mining and determine the best development path, process and timeline to achieve this vision.

Jan 1, 2008

Blasting is at first sight a simple operation. Blastholes are drilled in a suitable pattern, primed, charged with explosives, stemmed and finally the blastholes are connected together to give the appro- priate initiation sequence. In practice the action of the explosive takes place in the interior of an opaque rock mass and only the external faces of the rock mass to be blasted can be easily observed. The mechanisms of blasting cannot be observed directly and must be inferred from observations of the free face and meas- urements of particle movement made by sensors grouted into holes in the rock. Explosives react very rapidly, in some microse- conds and any instrumentation of a blast must have an appro- priate response time. In many mines several rock types can be encountered during production. Several different methods of blasting may be necessary to cope with changes in rock types espe- cially if weak rocks are found in the final limits. This also makes it difficult to be sure of getting a large enough volume of rock to perform a series of reproducible experiments. While there appears to be agreement on the mechanism of blasting it is unlikely that a detailed understanding of how all the variables that can be encountered in practice affect blasting. The ease of assessment of the results of blasting depends on the criteria used. It is easy to isolate, measure and count over- size boulders. It is however difficult and costly to get a complete fragment size distribution. Methods used to assess blasting can vary significantly from site to site and the ways in which data are collected, presented and analysed will vary making compari- son of blasts at several locations very difficult. The definition of an optimum blast can also vary with the type of blasting. The muck-pile profile and fragmentation will be different for a dragline to that for a truck and shovel operation. In order to be able to assess blasting the mechanism has to be understood. Th rock and explosive properties considered rele- vant to blasting can then be determined. This paper discusses the generally accepted mechanism of blasting. The on-site observa- tions to assess blasting are-then listed. The mechanism of blast- ing can also be modelled and the use of modelling to optimize hlaetina ie thPn Aiernccarl

Jan 1, 1988

By Sroka J

A comprehensive feasibility study should be submitted as part of the loan application to a financial institution for debt funding of a proposed project. Its scope should include technical, costing, marketing and other aspects pertinent to the project. The technical presentation should be sufficiently detailed to show that the assumpt- ions concerning future performance are realistic. A lender needs to be convinced that the capital and operating cost estimates are conservatively based with adequate allowances included for contingency and escalation. The marketing assumptions determine the level of revenue from which operating cost, debt servicing, and other commitments are to be met. The foregoing aspects establish the economic viability of the project, and are therefore relevant to the risk assessment and cash flow analysis carried out by a potential lender which determine his ultimate lending Decision

Jan 1, 1978

Pressures are foreseen for departments of metallurgy to make. radical changes in their undergraduate curricula. The curricula need to be made more attractive to high'school students in -order to increase the number of enrolled students. The distinctive character of extractive metallurgy needs to be emphasised to resist encroachment by chemical engineering. There should be content relevant to each of the professional functions and, particularly, to' society's broad expectations of metallurgists. Content, teaching methods, etc. need to be acceptable to women, mature-age -students, Aboriginals, and other groups, as well as young white males. Learning experiences should be negotiable by the students in response to the advent of learning packages delivered via personal computers. All of these needs could be satisfied by a radical change. in attitudes and objectives during the design; implementation and evaluation stages of . a new type of curriculum, using a wide range of problem-based learning experiences..

Jan 1, 1986

I am honoured to have been asked by Sir James Foots, the President of the Congress Organising Committee, to open this, the 13th Congress of the Council of Mining and Metallurgical Institutions. The theme you will be addressing over the next few days is "The Twenty First Century - Mining, for Mankind" - a theme that must be regarded as an enormous challenge for the entire minerals industry. Previous conferences, starting in 1924 in London and followed by two others in the United Kingdom, have also taken place in Canada (three), Southern Africa (three), Australasia (two), and Hong Kong (one), but this is the first to be held in Singapore.

Jan 1, 1986

Quality Assurance has become a buzzword amongst governments and industry. Notwithstanding the world class work done by its committees in developing codes of ethics and of practice in field geological handbooks, mining cost estimation handbooks, and reserve estimation, the AusIMM could better prepare its membership for QA. MICA could provide a simple set of guidelines to enable consultant members to develop their own QA procedures manual conforming to AusIMM Codes and to IS09003, and AS3903.

Jan 1, 1994

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

Analysis of the 2001 Australian census data set can be used to gain a detailed insight into the trends and levels of employment in different industry sectors. There is a common perception that employment of geoscientists within the mining industry and indeed across all industries has decreased significantly. However, the data shows that the number of individuals stating that they are geoscientists employed across all industries has decreased by only five per cent from 5336 in 1996 to 5067 in 2001. Within the mining industry (Australia and New Zealand Standard Industrial ClassificationÆs û ANZICÆs mining class), the number of geoscientists employed has decreased by ten per cent from 2701 in 1996 to 2441 in 2001. These figures, while showing a decrease, do not reflect the magnitude of the decrease commonly perceived. However, further analysis shows the number of geoscientists employed in mineral exploration may have decreased significantly more.

Jan 1, 2003

The Proterozoic Pb-Zn deposits of the Gulf of Carpentaria, Australia, include HYC (McArthur River), Mt. Isa, Dugald River, Lady Loretta and Hilton. Two seamingly incom- patible depositional models have been proposed to account for their origin. Finlow-Bates (1980), Large (1983) and Russell(1983) classify these-deposits as sediment-hosted submarine exhalative deposits. This class includes Rammelsberg, Meggen, Silvermines, Sullivan and others. In contrast, a lacus- trine, shallow-water origin has been advocated by Williams and Logan (1981), Logan and Williams (1984), Muir (1983) and Eugster (1985). The discrepancies between these two models can be removed by creating a separate class, that of continental sediment-hosted exhalative deposits.. HYC., Mt. Isa and Dugald belong to this class and their sediments were deposited in shallow, alkaline lakes. Metal- rich, hot, Na-Ca-Cl brines entered the basins along boundary faults and interacted with pore fluids and sediments, depositing-Cu-Zn-Pb sul- fides. Similar brines entered the Lady Loretta basin after marine flooding, depositing sulfi- des and barite, placing Lady Loretta into the class of marine Sedex deposits.

Jan 1, 1987

Organisations are starting to develop processes for achieving sustainability principles they have defined for their organisation. The foundation for these principles is now well accepted. The definition of a sustainability framework is a good starting point for any project. The delivery of the framework requires the organisation to think differently about how project objectives can be met. New tools are becoming available to help achieve the sustainability outcomes for the projects. This paper will examine the project building blocks that are necessary to ensure the sustainability framework can be achieved for the project. These include new approaches to decision-making processes and evaluation tools and when to apply them. An integrated approach with shared expertise to project delivery, which is applicable to the whole supply chain, will be discussed. This will cover sustainability procurement, integrated waste management, cleaner production and eco-efficiency, sustainable products and disposal. A project toolkit will be presented and some key project tools identified. The need for management support in undertaking these new approaches is critical, as is the need to develop partnerships and cooperative management to facilitate delivery.

Jan 1, 2004