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By D MacKay, W J. Bruckard

One of the mining worldÆs greatest challenges is to effectively use consumables (ie reagents and grinding media) to maximise metallurgical response, while minimising operating costs. It is anticipated that this paper will provide a logical frame work within which this can be achieved. The current study, at PerilyaÆs Broken Hill concentrator in the lead primary grinding/roughing circuits, examines the dependency of collector adsorption on Eh. The data demonstrates clearly that under the right grinding chemistry the addition of a xanthate collector during grinding can improve galena flotation. Further, operating the ball mill under the desired grinding chemistry regime leads to significant reductions in collector consumption whilst maintaining the metallurgical benefit.

Jan 1, 2008

By Watson D. F

Armstrong's (1983) criticisms of PhiIip and Watson's (1982b) note on optimal drilling patterns are based on misinterpretation, supported by errors in geometry. Furthermore, Armstrong argues conceptually from the perspective of Matheronian geostatistics, as does also Rudenno (1983a, b). Thus, both authors embrace a global, probabiIistic method of assessing spatial data sets, an approach that must be contrasted strongly with local, deterministic interpolation methods. Some of the important assumptions of geostatistics are outlined and the non-unique nature of the method discussed. A probabilistic approach can be judged appropriate when exploration data are erratic, or known to be unreliable, or when extrapolation is desired. Where data are treated as exact, kriging can give the most biased result if tested against other interpolation methods. We reiterate our previous conclusion that the equilateral triangular grid is approximately 30 per cent more efficient (in terms of numbers of drill holes) compared with a square grid for the same maximum interpolation distance. This is simply due to the improved isotropy of sampling. New, locally-based, deterministic methods for computing ore reserves seem to be required.

Jan 1, 1984

Although the last decade has seen the growth of many new licencing and approval requirements for the exploration and mining industries, there remains in each State of Australia and the Northern Territory a predominant "Mining Act" containing provisions for the grant of exploration and mining tenements. What then are the rights and duties of tenement holders either by virtue of a Mining Act or through other approval and licencing mechanisms? What rights and duties does a person acquire when he is granted an exploration licence or a mining lease? In this paper I will attempt to cover these types of questions using in particular examples from New South Wales. I will also refer to a range of other subordinate approvals and licences which today's society requires and the need for ethics and recognition of liabilities.

Jan 1, 1995

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

By N Robson, E Stephens

Australian mining companies are actively exploring for and developing mineral deposits throughout the world with interests in emerging markets such as Africa, Asia and South America. It is important to understand emerging market risk as this will affect the willingness of mining companies and financial institutions to invest in a country, especially with reference to their key asset, the mining licence or operating/concession agreement. Mining companies looking to develop new projects in emerging markets have different risk profiles than projects in countries such as Australia and Canada. Examples of key risks faced in emerging markets include: political û expropriation, nationalisation, contract frustration, currency inconvertibility, war, terrorism, strikes, riots and civil commotion; and legal û mining legislation, arbitration and dispute resolution, trade agreements. There is a problem in the difference in risk perceptions between mining companies, financial institutions and insurers. This can cause different stakeholders to carry out different evaluations of the risks faced by a project, resulting in confusion about the risk margin attached to any project. In a time where resource nationalisation and energy security are prompting governments to become more involved in the mining sector we run through some recent examples of mining companies that have had problems due to the key risks highlighted earlier. Importance of carrying out the right due diligence to replace perceptions with reality: early identification of risks û detailed due diligence on emerging market risks that may arise will help with their identification and mitigation, make use of companies that can help identify risks and suggest solutions, control the cost of financing û risk margin applied to a project finance loan will be influenced by the risks faced, and risk management and using political risk insurance. There are plenty of opportunities in emerging markets but it is important to recognise the associated risks. Detailed due diligence at an early stage will provide long-term benefits.

Jan 1, 2007

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 Pollard P. J

Australia is well endowed with both tin and tungsten resources, and is currently a significant producer of both commodities for the international market. The intensity of exploration activity for both metals has been rather sporadic, reflecting the changing market situation. Thus tin has experienced three major boom periods around 1880, 1907 and 1983, while tungsten prices peaked around 1917, 1953, 1970 and 1977. During the earlier periods, the major discoveries were located utilising simple prospecting techniques involving creek travers- ing and stream sediment panning. The resulting location of tin alluvials quickly led to the discovery of adjacent primary deposits. The major tungsten deposits were composed of quartz- wolframite, which was readily visible as mineralised float both within the drainage systems and on scree slopes. Thus by the early 1900s most of the currently significant deposits had been located. More recent exploration approaches have combined these tradi- tional methods with the development of exploration models based on evolving genetic concepts. Within tin systems the emergence of province styles of clas- sification combined with enhanced perceptions of tonnage-grade characteristics and improved geological models has enabled more effective exploration strategies. Province classification at the inter- national scale demonstrated a clear relationship between deposit type and geological environment and thus considerable attention was given to the range of provinces present within Australia. Tonnage-grade diagrams enabled the refinement of economic per- spectives, while detailed models provided the basis for localised search parameters.

Jan 1, 1988

The rare earths market is relatively small and slow growing. Three applications using mainly cerics rare earths : catalysts, glass-ceramics and metallurgy are volume market. Inside this slow moving frame, fast growing niches can be found lamp phosphors, permanent magnets, fine cera- mics... There is no specific ore for one given element, and the natural occurence of any ele- ment is almost constant in both monazite and basnaesite. This creates the "balance problem" that consists in the best compromise between shortage and over production. The general trend of prices is downward in constant money. Despite this difficult environment (price decrease, technology changes, etc...) lots of company have always been attrac- ted by the rare earth business.

Jan 1, 1986

The mineral sands deposit of Australia pose a number of unique, and quite unusual problems for the explorationist. Most concentrations of heavy minerals have been found in the unconsolidated sediments of the east and west coasts. Mineral sands mines open larger areas per tonne of concentrate than most other mines. This is because of the shallow depth of the sands containing the heavy mineral concentrations. Obtaining tenure can, by mining industry norms, be a massive operation due to the large areas to be examined and, particularly on the east coast, the large number of land holders encountered. A commercial development can still emanate from anything ranging from a small high grade body to a massive low grade deposit, the prices currently being obtained for rutile, zircon, ilmenite and monazite, although still modest when the remarkable properties and applications of these minerals are considered, is nevertheless attractive when compared to the prices being obtained for the base metals with the exception of gold. The current interest in the location and definition of new reserves of heavy minerals reflects this relative price attractiveness. The discovery of heavy mineral concentrates does not necessarily ensure the early establishment of a mine. Because of the cyclical nature of market prices, the average returns likely over the life of the mine permit the employment of only relatively simple, low cost, mining, concentration, and separation processes. If difficult mining conditions are encountered or the removal of small contaminants by complex metallurgical processes are required, then higher market prices must be obtained. Until the market is prepared to pay more for the commodities so produced, the resource will not be economic and lower cost reserves will be mined in preference. The Australian mineral sands industry has seen many closed mines because of past failures to properly assess the data base collected during the exploration and development phases of the failed projects.

Jan 1, 1987

THIS instrument, depends on the principle that, over a short period, the surfaee of a porous substance from which a liquid is evaporating receives the same amount of heat by conduction, convection, and radiation as it loses in the latent heat of the evaporating liquid. If, then, the amount of heat being received by a surface can be measured, the rate of evaporation can also be obtained. The Kata thermometer is also based on this principle differently applied.The instrument, as shown in Fig. 1, consists essentially of a thermometer with a sliding which is divided by three pointers into two equal parts which may be spaced so as to cover a distance of, for example, 5° of the thermometer scale. The instrument is calibrated so that the amount of heat required per unit area of the bulb to raise the menissus is known. The method of using the instrument is as follows:The slide is first set so that thc central pointer is at the temperature of the evaporating surface.The thermometer is cooled by any convenient means so that the meniscus is several below the lowest pointer. The thermometer is then placed near the evaporating surface, when the Ineniscus begins to rise and the time taken for it to rise from the lowest to the top pointer is measured. From this and the calibration results the amount of heat retained per unit area of the bulb at the mean temperature...

Jan 1, 1928

The needs for improved technology for the mineral industry are widely recognised and a summary list is given. Ways in which technology has been introduced into the industry are discussed, as are the means by which the general process of technology transfer takes place. Some possible sources of improved and new technology are considered, together with the constraints to its introduction into the industry. Responses to recent external influences on the industry are discussed in relation to their effects on technology development.

Jan 1, 1986

Congratulations on your considerable enterprise in securing the opportunity to have this international conference here in Brisbane - and congratulations on your success in attracting such a distinguished audience from so many nations, with such a broad selection of papers. It is a notable achievement that in the year in which Australia is celebrating two hundred years since settlers first came fran Britain, The Australasian Institute of Mining and Metallurgy is responsible for some ten major conferences, of which at least four are specifically international, or have a very strong international involvement.

Jan 1, 1988

Traditional methods for calibrating the most customisable forms of GyÆs formula for the prediction of sampling variances involve a large amount of experimental work. This work is often extremely sensitive to outlier treatment and often relies on assumptions. A general methodology called æthe consistency methodÆ, however, has proven efficient in guiding these critical steps and adding objectivity to these subjective tasks. After a quick exposition of its principle, it is shown how it can also be used to reduce the amount of experimental work when dictated by budgets.

Jan 1, 2008

Water Savings and Coal Product Compromise

Sep 13, 2010

By Moskovits EE

Spodumene was recovered from pegmatite by flota.ticn in lAoretory tests and ;pilot-plant, operation using an anionic collector e1 ulsi3.n. i sir_tilar process applied to beryl pegmatite g^.ve encouraging results.

Jan 1, 1963

Cyanide is a significant contributor to the cost of producing gold. Any reduction in cyanide consumption that is achieved through more reliable measurement, and/or more efficient management of cyanide dosing rates, can produce a significant financial saving to the mine operation.

Jan 1, 1997

By P S. R Reddy, V N. Misra

The iron ore deposits in India are rich in iron content but usually contains high alumina and silica. The current industrial practice results three products namely lump, fines and slimes. The lump and fines with or without beneficiation are directly fed to the blast furnace and sintering plant respectively while the super fines or slimes are presently discarded as tailings. Around eight million tonnes of iron ore slimes estimated as being 15 - 20 per cent by weight of run of mine ore containing ~48 - 62 per cent Fe, is discarded every year causing huge loss to the Indian iron ore industry. In addition, these slimes stored in massive tailing ponds pose enormous environmental and ecological problems. Extensive investigations have been carried out on three iron ore slimes generated at Barsua, Bolani and Meghahatuburu iron ore mines of India. The studies include physical, chemical, mineralogical characterisation and beneficiation studies adopting conventional hydroclyclone and wet high intensity magnetic separator. The characterisation studies have indicated that most of the gangue minerals are accumulated in finer fractions. The studies on hydrocyclone and magnetic separation had indicated that an iron concentrate of 61 - 65 per cent Fe could be obtained by recovering 59 - 78 per cent of the iron values present in the slimes. Depending on the nature of the slimes the alumina and silica levels have been brought down to 2.5 and 1.0 per cent respectively. The effects of different operating and design variables along with detailed characterisation studies have been highlighted.

Jan 1, 2002

Computer software has been developed to link real-time information generated by underground mine ventilation airflow monitoring sensors into a network simulation program to undertake network simulations and allow interpretation of key system data and operational changes. Results were used in the development of a computerised monitoring and simulation system to provide immediate or real-time data on air behaviour within each branch of an underground mine ventilation network through linking of sensors to the ventilation network simulation software. The outcome of the project is an online system that can report changes in the mine ventilation system, allow causes of changes to be isolated and rectified, improve balancing of available air throughout the mine, allow improved approaches to regulator setting and dispense with much of the labour used for underground ventilation measurement. The work activities in both coal and metalliferous Australian mines have involved examination and modelling of regulators, software modification and considerable mine site testing and optimising activities. There is some discussion on approaches to control of flow through ventilation systems with increased information. New systems will be part of a total mine information management system. They will have to be cost effective and justified by gains in productivity. New systems will need to provide simulation of contaminant production such as diesels, vehicle heat, strata heat, radiation, blast fumes and other gases. More robust real-time ventilation simulation systems will be required. Personnel and vehicle identification and production tracking will be collected to provide integrated ventilation system monitoring and control. This paper examines a study to gain greater understanding of computerised real-time airflow monitoring and control within the mine production system to provide immediate simulated information in each branch of an underground ventilation network and to allow interpretation of key system data and operational changes. A case study implementing a real-time airflow monitoring and control is discussed. Approaches to control of flow through ventilation systems with increased information are discussed. The concept of a system that can be linked to or be part of a total mine information management system is developed. Such a system can form the base for mine automation that allows mines to incrementally and cost effectively implement monitoring and control to further seek gains in productivity.

Jan 1, 2005

Unprecedented political, economic, and social change throughout the world will have an increasingly profound effect on the dynamics of the world's mining industry. Analysis of the early financial trends in this development (statistics on exploration expenditure, and investment flows) gives some insight into the magnitude of structural change and its implications for established mining economics and companies.Increasing confidence in the stability of many third world and developing countries is attracting exploration and investment capital that had previously been largely directed to established mining economies in North America, Australia, Europe and Southern Africa. Some of the projects requiring capital and technology in the CIS, Africa and Latin America are technically very attractive. The end of the 'cold war' and the influence of the IMF is gradually changing their risk profile for mining investment.

Jan 1, 1993

The paper describes the studies conducted to date on the short term adsorption/desorption of gases in coal from the point of view of developing techniques to predict imminent outbursting conditions in coal mines. A number of different parameters such as'dP express, K' and AV 0/60 etc. which have been effectively used overseas were studied on samples of coal from Westcliff and Leichhardt Colliery. Results indicate that these do not seem to be valid indices for predicting an outbursting condition. Based upon desorption isotherms, a new index defined as "L" has been developed which shows promising results. This index is in a position to differentiate the changes in the structures of coal and its proness to outbursts. The "LZ value determinations and its usefulness opens a new field where it would be possible to determine outbursting conditions from existing drill cores obtained during exploration studies or from long holes drilled in advance from underground workings. The index is more or less independent of the time elapsed between the extraction of a sample and the conduct of the test. The test for "L" can be conducted'on site or in the laboratory. The test is simple, easy to carry out and the "L" value for a sample can be calculated in less than 20 minutes. It could be adapted as a routine test for monitoring outburst conditions in mines.

Jan 1, 1980