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The Metallurgical processes used in the gold industry in Queensland since the 1850's are reviewed. The major upswing in, gold processing this decade has brought the technology of heap leaching, carbon in pulp and carbon in leach, flotation for gold and tailings retreatment to Queensland. In many cases operators have developed or improved these processes to treat difficult ores or to cope with local climatic conditions.

Jan 1, 1989

By Harris HR

This paper documents the selection, installation and performance of six, seventeen cubic metre, Dorr-Oliver flotation cells for primary zinc flotation at the North Mine in Broken Hill. The cells were installed to replace fifty, small cells, and despite initial design problems, have per- formed satisfactorily.

Jan 1, 1988

When mining of ilmenite deposits wet process of preparation is traditionally used. But this method needs large volume of water. The problem of water deficiency is characteristic of many regions of the Republic of Kazakhstan. The Satpayevskoye ilmenite deposit is situated in the East Kazakhstan, its location has problems with water, and the mineralogical composition of rock is unfavourable: rocks contain up to 40 per cent of clays. That is why designers made a decision to use dry process of preparation for processing of these ores. Offered scheme and equipment selection are presented in this paper.

Jan 1, 2003

The competitiveness and future growth of the Australian mineral resources industry face a number of challenges. The paper addresses key factors likely to influence the attainment of high performance and continuous improvement including organisational leadership, management/employee relations, technology, safety, health and the environment. Business practices such as benchmarking, Total Quality Management and re-engineering to achieve process and performance improvements are commented on. Future success for the industry will largely hinge on global business skills, a sustained focus on Quality principles and achieving performance through people.

Jan 1, 1997

By Chen B

In recent years great efforts have been made in the optimisation of ball mill operation. This paper describes a methodology developed for modelling and optimising the steady-state grinding process. Thirteen basic similarity numbers of the process are derived. Based on these similarity numbers, we build a group of mathematical models which give a full description of the relation between dependent and independent variables. The parameter estimation and multi-objective optimisation of the grinding process have been done using these models, and validated with experiments in a continuous laboratory-scale ball mill.

Jan 1, 1993

Two recently published studies have considered whether and how robots, which have been designed for manufacturing applications, could find use in mining. The conclusions of both studies, if not identical, are compatible. Automation of mining activities will continue. Robots, at least in the short term, will have little application in mining. However, robotic concepts, both hardware and software, are of considerable relevance to mining automation, and can be anticipated to diffuse gradually into mine environments. The present paper is intended to convey the current state of thought on this subject to IFAC Symposium participants who may be unfamiliar with the referenced studies, and is not intended to report previously unpublished research.

Jan 1, 1985

By Quast K. B

Laboratory batch rod and ball milling tests were conducted on samples of Heavy Medium Separator (HMS) sinks from Renison Tin Limited. The product size distributions for this heterogeneous material were very different to similarly sized homogenous material previously reported by the authors. The effects of pulp density on product size distributions were only evident at pulp densities greater than 80 per cent solids. At high solids density, the major weight distribution product peak fell and broadened indicating less efficient breakage, particularly for rod milling. Tin distribution in the ground products was also affected by pUlp density, and there was always less cumulative per cent tin than cumulative per cent weight, ie there was no tendency for cassiterite to slime down to 10/lm.

Jan 1, 1995

By Seedsman R

The fundamentals concepts of roof support are similar between coal mining, metal mining and tunnelling and yet there are different design approaches, different hardware, and different levels of site investigation. This should not be the case and this paper discusses the key geotechnical issues that should underlie all roof support design - the need to reinforce defects. A design method to build a beam in laminated rock under high horizontal stresses is presented. The method allows for changing rock strengths, defect properties and varying horizontal stresses. At one level the design can be implemented with design charts and tables. Lessons learnt during the implementation of the designs at 5 different mine sites are Discussed.

Jan 1, 1998

The impact of computers on the mining industry has increased for the past twenty years in most parts of the world. The application of computers in the mining industry has been demonstrated in areas such as geological data analysis, ore reserve estimation, mine planning, and manpower training. There is also a general concern in this country regarding the computing background of graduating mining engineers from the Australian higher institutions of learning. This paper describes specific steps which have been taken at the Department of Civil and Mining Engineering, The University of Wollongong to provide adequate computing background to mining engineering graduates. Specific topics discussed include hardware and software available to students and how "computers" have been integrated into the mining engineering course.

Jan 1, 1986

Poorly designed sampling protocols generally result in high project risk by artificially increasing grade variability (ie the nugget effect). Sample collection, preparation and assay protocols that suit the ore type, together with QA/QC systems, will reduce this risk. All reporting codes (eg JORC, 2004) require the Competent Person to consider the quality and implication of sampling and assaying programs. High sampling errors beget higher project uncertainty; despite this fact, sampling does not receive the attention it deserves. The case studies presented show that many sampling issues frequently go unrecognised or unaddressed, resulting in poor project decisions during exploration through to feasibility and production. The overall conclusion is that correct sampling is critical to mining project success and that there is often a need for its optimisation.

Jan 1, 2007

By D H. Bell

The potential for extracting gravel materials from active floodplain and channel areas has been investigated for three West Coast rivers û the Grey, Inangahua and Whataroa. Studies have focused primarily on resource availability and replenishment, but there are clearly also environmental management issues associated with such a proposal. The potential uses for of extracted materials include roading and concrete aggregates, as well as railway ballast, whilst a major benefit would be in assisting with flood control and channel maintenance in a naturally aggrading system. Sediment movement in the rivers has been examined at three scales; long-term (>100 years), medium-term (10 - 100 years) and short-term (<10 years). Long-term sediment movement is based on geological and geomorphological information, such as cyclic fan development and down-cutting in the Whataroa River where sediment input appears to be largely controlled by Alpine Fault rupture events. Medium-term assessment relied on air-photo interpretations over a period of about 50 years, with the mapping of channel changes and bank migration. Short term changes were evaluated from gauging records and other hydrological data, and took account of the development of an armour layer in these gravel-bed river systems. It was concluded that sediment in the lower reaches of each river was suitable for most aggregate uses, although input of more weathered Greenland Group materials in the upper reaches (eg of the Mawhera-iti or Little Grey) resulted in product that was not satisfactory for sealing chip or railway ballast. Of greater importance was the fact that short-term studies showed that a minimum threshold of flow was required for gravel entrainment, and that significant sediment movement only occurred above the one-year return period flood. Ongoing monitoring of river profiles, with accompanying flow gauging, would clearly be necessary were a substantial increase in river bed extraction to be permitted by The West Coast Regional Council.

Jan 1, 2003

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

By Pirvics AI, Whitworth NR, Tuppurainen JMI

Process control applications to the unit operations in both the Lead and Copper Smelters are reviewed. The basic aim of this control is to smooth plant inputs to produce an output of consistent quality in terms of chemical composition, temperature and physical properties. Most effort has been put into the process bottlenecks, namely in the process baghouse of the Lead Smelter and in the Copper Smelter reverberatory furnaces. The method of approach is discussed, firstly extensive plant measurement and data logging plus identification of factors which most affect the unit operation and secondly control of these factors to smooth out variations. This has been possible due to the development in-house of on-line instruments to measure the critical variables and the external use of computers for plant control. Some of these instrument developments are also briefly discussed.

Jan 1, 1984

In recent decades the awareness of environmental issues by the general public has developed at an accelerat- ing rate. This is the result of a number of factors including more scientific knowledge of environments and of the impacts of modern society upon them, higher levels of education, the opportunity for people to travel more, and the success of the various communication media in bringing in- formation to the communities of the world about such environmental crises or threats as the smogs of Los Angeles and London, the Torrey Canyon and Santa Barbara oilspills, Minamata disease in Japan, the spread of the Crown of Thorns starfish, the disposal of toxic industrial wastes into the Upper Rhine, the discovery of high mercury and zinc contents in marine foods in southern Australian waters, and the proposal to mine limestone at Precipitous Bluff in Tasmania.

Jan 1, 1975

To grow a mining company today is seen to be challenged by the reduced interest in resources companies by the financial markets, the complexity of native title and a somewhat depressed commodity cycle. However, the opportunity to grow production and sales in a mining company are as numerous as they have ever been. It is the challenge of growing significant shareholder value that is difficult. The distinction between growth in æcompany sizeÆ and growth in æshareholder valueÆ is an important distinction upon which some resource companies are now firmly focussed. The equity market/commodity market cycle can provide windows of opportunity to consolidate and expand a company for the benefit of shareholders. These benefits may not be reflected until more buoyant equity markets return but, as the cycle turns, as it surely will, those with the foresight to position themselves may be richly rewarded.

Jan 1, 2000

This data is intended to provide a quantative cost comparison of one 40 800 kg. pull down rotary blast hole drill versus two smalter drills in the 18 100 kg. pull down class. While this cost analysis is affected by blast design, this paper is not intended to be a treatise on blasting theory and therefore places more emphasis on costs than on blast design. All costs, prices and production rates in this paper are estimates and should be used for comparison purposes only. The drills are sized in order to maintain a production rate sufficient to stay ahead of a dragline that is excavating in an average overburden (sandstone and shale). The large drill will use 270mm bit and penetrate at a rate of 0.012 m/s (scheduled basis). The small drill will use 170mm bit and penetrate at a rate of 0.010 m/s (scheduled basis).

Jan 1, 1986

Until 1937, the mining of ore was carried out by conventional methods, using pneumatic drills and standard drill steel. The adoption of the diamond drill, formerly used for exploration work, for blast hole drilling in stopes, was first developed by Noranda Mines Limited, Noranda, Quebec, although it had been used previously in Northern Ontario and Western United States, to remove weak pillars and ore remnants left by conventional methods. Previous to the adoption of the diamond drill method at Noranda, a sub-level benching system of stoping was used. Sub-levels were driven at 35 ft. intervals and the benches drilled off by pneumatic drills using sectional steel. Results were very satisfactory, in sulphide ore, where the drilling was comparatively easy, but in the harder rhyolitestopes the footage drilled per machine-shift was only half of that obtained in the sulphide stopes, and owing to the high gauge loss, there was often difficulty in drilling holes to the required depth. This led to trials with the diamond drill for this type of work. While the cost per foot was more than with sectional steel, an appreciable saving in development work could be made by increasing the sublevel interval from 35 ft. to 60 ft., and stope widths from 60 to 100 ft. This saving, together with the increase in blasting efficiency, resulted in a substantial reduction in overall costs.CONDITIONS FOR SUCCESSFUL APPLICATIONWhile long diamond drill blast-hole mining has widespread application, there are certain conditions which appear to be desirable, if not absolutely necessary, for its successful use.

Jan 1, 1946

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

From December 1994 to November 1997 Odin MiningÆs Estero Hondo alluvial gold mine in western Ecuador washed almost 3.2 million bank cubic metres of gravel to produce just over 2600 kilograms of pure gold at a recovered grade of about 0.8 grams per bank cubic metre. The operation was a simple open pit. Draglines stripped the overburden, backhoes mined the gravel, and trucks transported the ore to a stationary, gravity-based wash plant for processing. At start-up the planned throughput was 55 000 bank cubic metres/month, but a year later this had been increased to 100 000 bank cubic metres/month. From April 1993 to July 1997 a total of 440 churn drill holes and 15 pits were sunk to test the property. The methods used to prepare the resource and reserve estimates from the raw field data are described, and seven sets of completed estimates are used to track the evolution of the projectÆs resource/reserve base through the exploration, feasibility and production stages.

Jan 1, 2003

The ER&S Company operates a copper sinter plant, blast furnace and converter smelting complex at Port Kembla. Eighty percent of the smelter feed is dirty copper concentrates that contain some lead and zinc. The remaining twenty percent of the smelter feed is copper bearing secondary materials, some of which contain lead, zinc and tin. A predominately lead/zinc fume is produced during the smelting and converting of this feed mix. The composition and tonnage of fume produced at Port Kembla has varied over the years as the smelter feed sources have changed. The economic processing of the fume has always been dependent on the value of the metals contained in the fume and on the fume composition. Both pyrometallurgical and hydrometallurgical methods have been used to treat the fume for the recovery of some or all of the following metals - lead, zinc, tin, copper, cadmium, silver and bismuth. A detailed description of the treatment methods that have been investigated and used to process ER&S fume is given.

Jan 1, 1984