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High precision GPS systems for mining are accurate to within a few centimetres. Typical systems consist of one or more GPS antenna, GPS boards, sensors to detect the position of the blade or bucket of the machine radios to pick up correction signals, a computer to control the system and a display screen to give instructions and information to the operator. GPS systems offer two benefits û they give information to the operator to get his job done faster and more accurately and they can send information to management about how the job was done. On dozers, GPS systems allow the operator to accurately complete earthmoving jobs with no survey pegs. On hydraulic excavators the systems can be used to accurately locate the position of the bucket teeth for selective mining. On blasthole drills the systems can guide the operator to each hole and record accurate as-drilled plans. By reporting the position of the blade or bucket in three dimensions it is possible to continuously upgrade a mapfile of the excavation. From this file it is then possible to report productivity numbers in real time. High precision GPS works best with a minimum of five satellites visible. This may be difficult in a pit. Systems which also access the Russian GLONASSS satellites offer significantly better uptime. GPS systems will become indispensable for efficient mining operations in the future.

Jan 1, 2003

By Woodcock JT

Successful chemical control of flotation requires practical solutions to many problems. A brief discussion is first given of those para- meters which can be controlled and those which it would be desirable to control. Suitable analytical methods for application to flowing pulp and to clear solution from pulp are out- lined in relation to on-line and off-line control. Practical problems of deciding where a measurement is to be made or a sample is to be taken and how the sample is to be prepared and presented to the measuring device are then considered. Equipment calibration and maintenance are considered in relation to the above factors.

Jan 1, 1978

When a joint venture is established between a major and a minor, the co-venturers often have a number of divergent interests; the major may have put up significantly more capital into the project and will want to protect its investement; the major may have more financial resources and be more readily to commit capital to the project; the major may have more technical resources and expertise to provide to the project; the major may have other competing demands for its capital; the minor may be relying on rapid development of the project as its sole source of cash flow. Successful joint ventures arise when the co-venturers understand each others' interests and attempt to satisfy these interests. This could be achived by having a clear process and timetable for development of the project coupled with clear rules for distribution of income, the commitment of capital to the project and the provision of inter-company services. If divergent interests are either regulated clearly or eliminated, both co-venturers are more likely to seek common objectives in the joint venture with less scope for conflict. This paper, written from the perspective of a major, examines means of establishing successful joint ventures between majors and minors.

Jan 1, 1997

By Jimbo I, Ogawa O

A series of experiments was carried out to investigate the solubilities of copper, arsenic, antimony and bismuth in silica-saturated iron silicate slags under controlled oxygen partial pressures at 1200 and 1250¦C. Molten copper containing each of the above elements was kept in contact with a slag in a silica crucible for 24 or 48 hours to attain equilibrium. No me- chanical entrapment of metal into the slag was observed. The appearance of the magnetite phase in the slag was avoided by holding oxygen potentials at substantially lower values than that evaluated from available data on iron silicate slags. Solubilities of copper, arsenic, antimony and bismuth in slags were plotted against oxy- gen potentials and both oxidic and atomic types of dissolution were found, except in the case of arsenic, from the dependencies of the solubili- ties on the oxygen potential and from positive intercepts of regression lines when extra- polated to zero oxygen potential. The dissolu- tion of arsenic seemed mostly oxidic. Distri- bution coefficients of arseò,ic, antimony and bismuth between copper and slag are also Discussed.

Jan 1, 1980

There have been many developments in recent years in pipeline transport to enable them to be more widely used in industry. Substantial tonnages of materials that are not affected by water, such as coal and other minerals, aggregates and wastes, can be moved over considerable distances in quite small diameter pipes. Where there are no existing road or rail facilities, long-distance pipelines are usually cheaper to install, and this advantage increases in difficult terrain. Pipeline operators all over the world assert that hydraulic lines pay for themselves in a relatively short time, in spite of the heavy capital outlay, and this is equally true for lines convey-ing slurries or pastes within a plant complex.'This paper reviews some of the more important investigations in the hydraulic transport field. Although reference to systems carrying a wide range of materials is made, the majority of recent published data centres on coal transport.The paper looks at the application to a wide range of particle sizes, the development of non-aqueous slurrying media and coal/water fuels. The review also looks at some of the equipment being proposed to provide more reliable operation and in particular the range of solids-handling pumps now available.-The paper goes on to identify areas where further research and development is required and some of the many organisations undertaking this work.

Jan 1, 1985

Chief Geologist, Groundwater and Engineering Geology Branch South Australian Department of Mines and Energy The six papers submitted for consideration during this session include two dealing with techniques for measing rock mass behaviour, including permeability, in boreholes, one describing the use of surface geophysical methods to delineate pollution plumes in groundwater together with analytical modelling of the plume, and one presenting a biological tracer technique applied to the determination of the origin of water entering underground mine workings. A paper describing dewatering at a base metal mine in Queensland includes an account of the investigation techniques employed to establish a conceptual model as a basis for the evaluation of various dewatering strategies. Of considerable interest is the use of a field gravity survey to delineate a zone of highly weathered rock which forms the major aquifer at the site.

Jan 1, 1988

The Mineral Resources Act 1989 was assented to on 25th October, 1989 after more than two years of consultation and negotiation between Government, the mining industry and other affected parties particularly the major rural organisations.The legislation proposes major conceptual changes in a number of areas and adopts a totally new approach to the definition of land and the mechanisms available to the mining industry for accessing such land.Unfortunately the passage of the legislation through Parliament coincided with the lead-up to the State election. Ultimately it became an election issue generating much adverse comment in the media particularly from rural and landholder groups. It was obvious that much of this anti-mining propaganda resulted from a lack of understanding of the legislation and the benefits that flow to the majority of landholders as well as the mining industry.It is essential that the contents of the Mineral Resources Act be thoroughly understood by all parties. Only then will all the State's resources be able to be developed in a multiple land use environment.This paper outlines the philosophy behind the new Act and the more important provisions contained therein.

Jan 1, 1990

By Brasnett TC

A wide variety of problems are encountered on a day to day operating basis in the Isa Mine Concentrators. These vary from complex textural problems in the lead-zinc concentrator and their subsequent effect on grinding and flotation to scheduling of converter slag treatment in a chalcopyrite concentrator. With the advent of process control, metallurgists need to specialise and keep up to date with technology improvements. This paper will attempt to describe the significant problems'faced by a Metallurgist û Control.

Jan 1, 1978

By Bulters J, Sheppard I

Two blasthole density logging programmes have been conducted on the Mt Whaleback iron ore mine to evaluate the use of this type of logging as an aid to blast pattern design. The first programme also involved the setting up of a Density Test facility with which to calibrate the density probe. The programmes indicated that about 22-23 blastholes can be consistently logged per day at a cost of $1.30 per metre. Even though this is only half the rate required to log the average number of blastholes drilled daily on Mt Whaleback, testwork indicated that no significant loss of accuracy results if only half the holes in a pattern are logged. The major results of the programmes were: 1. The density range for black pyritic Shale is 2.2-2,9 g/cc. 2. The density range for soft to medium hard BIF is 2.1-3.0 g/cc. 3. The density range for hard BIF is 3.0-3.6 g/cc. 4. The front row blastholes show consistently lower densities than the main body holes due to blast damage. 5. A low density zone extending to a maximum depth of 6 m occurs at the top of most blastholes and results from blast damage from the bench above. These density results have been used to implement savings in drilling and blasting via pattern expansion and charge optimisation of blastholes. Eight ore

Jan 1, 1986

The Committee for Mineral Reserves International Reporting Standards (CRIRSCO) was formed in 1994 to promote development and adoption of international standards for estimation and reporting of exploration results, mineral resources and mineral reserves. The CRIRSCO standards have been accepted by most mining companies and professional societies worldwide. Market regulators from Australia, South Africa and Canada require that these standards be followed when releasing public information. Among these requirements is the use of specific definitions for what constitutes exploration results, mineral resources and mineral reserves. If such information is publicly disclosed in must be estimated by a Competent or Qualified Person. In the United States of America, public disclosures are regulated by the US Securities and Exchange Commission. The SEC does not recognise the CRIRSCO guidelines, and some of the SEC requirements for public release of information are materially different from those applicable in other countries. The CRIRSCO definitions and the Competent Person requirements are reviewed and compared with those of the SEC. The organisation of the SEC and its rule making process are briefly discussed. Ongoing efforts to bring the US regulatory requirements closer to those applicable in other countries are presented, as well as other activities that CRIRSCO is entertaining with the United Nations, the International Accounting Standard Board and other international organisations to reach the objective of worldwide standardisation of reporting procedures.

Jan 1, 2006

In planning and operating mining projects, managers must take into account economic conditions in foreign markets in addition to Australian conditions. As the manager has little influence over the price or the demand for the product, it is particularly important that close attention is paid to the control of costs to ensure that the mining operation remains competitive with foreign producers. This is not necessarily true for some sectors of the domestic manufacturing industry where foreign competition is restricted and costs can be passed on to consumers because of the protection afforded by tariffs. The effects of protection on the cost structure of Australian industry are more pervasive than is commonly understood. The issue of protection is particularly important to the Australian mining industry management because the cost burdens imposed by local protection must be absorbed within profit margins. Furthermore, because protected industries are effectively subsidised to use scarce resources such as skilled labour, the development of more efficient industries such as mining is inhibited. The mining industry has much to gain from any relaxation in protection policy, and hence the issue is of considerable importance to all managers in the mining industry concerned with costs.

Jan 1, 1980

By Hyde L. J

Blasting is one of the available technologies to be employed in underground excavation systems. In many instances it can be the only technology which is suitable. The recent moves towards more mechanised working systems is resulting in a reduced awareness of new blasting practices and technologies on the part of many excavation engineers. Recent developments in blasting systems can be utilised to significantly improve operating efficiency, reduce total cycle times, better comply with regional environmental constraints and reduce the total cost of underground excavation. Blasting is and will remain, a very adaptable and exciting alternative which is far from boring.

Jan 1, 1987

By Dorricott M. G

Rock bolt installation is generally carried out in two steps. First the hole is drilled and the drill steel is extracted, then the bolt is inserted into the hole and tightened or grouted. With single pass bolting (SPB), however, these two steps can be carried out at the same time. This kind of bolting system has at least three advantages, (1) the time used for the bolt installation could be reduced, (2) the condition of safety for the operators could be improved, and (3) the degree of automation of the rock bolting practice could be increased. The study presented in this paper is concerned with the development of the SPB system. The current state of the system is discussed, and further improvement of the technique is explored.

Jan 1, 1992

University education in Australia is changing, driven by greater market orientation, reduced funding available per student, especially in the higher-cost minerals industry disciplines, and the call for more flexible delivery of subjects and courses to meet changing lifestyles and expectations. The opportunity exists for a true partnership to develop between industry, government and academia that will reshape minerals education in Australia and secure the future supply of the specialists industry needs to maintain international competitiveness. If this partnership does not emerge, it is anticipated that AustraliaÆs somewhat fragmented and unstable higher education system, especially in the disciplines of particular relevance to the minerals industry, will be put under further pressure so decreasing its effectiveness to produce quality graduates. The Minerals Council of Australia in 1998 published æBack from the BrinkÆ, a discussion paper which proposed strategies to build a world class minerals tertiary education system in Australia. Those strategies are now being implemented collaboratively with principal emphasis on the disciplines of mining engineering, metallurgy and earth science and as far as process is concerned, on the necessity to æcooperate to competeÆ. For metallurgy, the challenge is to integrate more closely undergraduate teaching with the existing world-class research centres and to link the tertiary institutions in such a manner that the strengths of all components are harnessed and then made available nationally in major population centres and at remote sites where appropriate. For industry the challenge is to build effective partnerships with the academic community that will enable and assist the agreed course of action to take place.

Jan 1, 2000

By T Tran, F Lucien

Supercritical fluids (SCFs) have gained recognition as solvents for the extraction of a wide range of organic materials. Their principle advantages over conventional organic solvents are that they possess much more favourable transport properties and that such properties can be easily altered by adjusting the system temperature and/or pressure. More recently, SCF solvents have been employed in the extraction of metal ions. The direct extraction of metal ions using SCFs such as CO2 is normally not possible due to the charge neutralisation requirement for solubilisation. However, extraction can be achieved with a SCF solvent containing an organic complexing agent as a cosolvent (Laintz et al, 1992; Laintz and Tachikawa, 1994; Dehghani, 1996). The role of the SCF is therefore similar to the role of a diluent in conventional liquid-liquid or solvent extraction processes. In this regard, SC-CO2 is a particularly good diluent since it exhibits good solubility for many organic complexing agents. The extraction of metals with SCF solvents has been examined mainly in the analysis of environmental samples and the treatment of metal contaminated wastes. Nonetheless, some interesting results have been reported recently on the extraction of rare earth metals, which highlight the potential of SCF solvents in mineral processing applications (Laintz and Tachikawa, 1994; Dehghani, 1996).

Jan 1, 2000

By G De Tomi, R Sousa, A Lapworth

One of the current challenges for iron ore producers is the ability to respond to changes in ROM stockpile specifications in a quick and cost-efficient manner. The decision-making process to respond to such changes is normally associated with grade-control and short-term mine planning activities, from where new operating instructions to the mine are provided. Mines are under increasing pressure from changes in the industry, such as a scarcity of skilled staff; a higher turnover of skilled employees and tighter product specifications. The quality of operational activities easily suffers as a result of these pressures. The technology that supports operational activities is often poorly implemented, which results in systems being unsustainable and poorly understood by the organisation. All successful technology implementations rely on the people, processes and technologies involved being well understood. Because of the complex nature of mining, the processes that underpin mine planning, scheduling and operational control are often not well defined. This results in activities undertaken by individual departments being poorly integrated. Datamine has developed a set of tools and methods for decomposing; capturing and documenting processes and ensuring those are embodied in implemented solutions. A case study of such a solution is the GEROS planning system, which has been successfully implemented at CVRDÆs Southern Iron Ore System, in Minas Gerais, Brazil.

Jan 1, 2005

By Warren M

Many Australian tunnelling and mining companies regularly investigate different methods or equipment in an attempt to keep ahead of their competition. Sometimes the result is a new approach or process which wins a tender or provides an advanced solution to a problem.The Australian Government has a policy of encouraging forward thinking among Australian companies and provides a range of incentives. One of these incentives is currently available retrospectively to 1985 - 86, and the registration process is relatively simple with only one form to be completed. Companies who investigate methods of raising productivity could be reimbursed for the costs of the investigation.

Jan 1, 1993

By Moorrees C

Carbonic acid leaching of crude iron-containing magnesia derived from Savage River magnesite yields a magnesium bicarbonate leachate with a substantial soluble iron concentration. The iron concentration depends upon the leaching conditions (particularly time, temperature and pulp density) but is generally in the range 0.005-0.5 g/litre. If this soluble iron is not removed prior to the precipitation of the magnesium as a hydrated carbonate, then this product will be contaminated by the iron, and will not yield a final product (high-purity magnesia) that meets specifications.The soluble iron content of the magnesium bicarbonate leachate can be reduced to an acceptable level by addition of solid aluminium sulphate either during carbonic acid, leaching of the crude calcine or to the clarified leachate. Chemical analysis and X-ray diffraction revealed that the iron is precipitated as an iron-containing hydrotalcite-type compound, [Mg6(Al,Fe)2(OH)16]CO3.4H2O. The actual composition of the precipitate depends on the amount of aluminium sulphate added and the precipitation technique used. Because precipitation of iron in this manner also results in reduced magnesium recovery from the leachates, It WIll be necessary to develop methods for recovering the magnesium component of the precipitates.

Jan 1, 1984

By S C. Goel

The Obuasi Mine in Ghana, West Africa is the largest producing gold mine in Africa, outside South Africa. The mine has changed from a mine producing from narrow vein, high grade quartz orebodies to a mine producing from wide, lower grade sulphide rebodies. Traditionally mining methods were cut and fill and sublevel caving. Now the preferred stoping methodologyis long hole open stoping. Transverse or longitudinal methods are both used, dependent on the orebody characteristics. The change has been technically, socially, economically and politicallychallenging and at times has tested the abilities of those responsible for the operation of the mine. However, the benefits have been many. Safety has improved significantly, ounces from underground have doubled. Productivityhas doubled and underground unit costs have reduced bya third. These achievements have allowed the Obuasi mine to staycompetiti ve in this time of falling gold price. During 1999 and 2000 a full review of the mining and processing operations was undertaken, and as a result, the mine is now in a phase of restructure. Efforts are being made across the mine to improve efficiencies and to reduce costs. The future for the Obuasi Mine is an exciting one.

Jan 1, 2000

By G K. Robinson

The existence of bias in samples taken by cross-stream sample cutters has been investigated using three-dimensional discrete element method (DEM) modelling. Detailed quantitative information on overall extraction ratios, size specific extraction ratios, missed and extra sample components can be made by comparing a reference sample to the actual sample. A key advantage of using this modelling approach over physical experimentation is that the reference sample can be measured on precisely the same portion of the stream of material as the actual sample, thereby allowing the elimination of a significant fraction of the variability and allowing statistically significant results to be obtained using many fewer replicates. Quantitative analysis of results broadly supports the commonly-used rule that the cutter aperture should be at least three times the nominal top-size of the material being sampled, but does not support the commonly-used rule requiring increase in cutter aperture if the cutter speed exceeds 0.6 m/s. Sampler performance can be understood in terms of the balance of forces in the congested region of material formed by the slowing of the particle stream due to collisional interactions around the mouth of the cutter.

Jan 1, 2008