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The deep seafloor in Papua New Guinea's proposed Exclusive Economic Zone appears to be a gold-rich province in the same sense as the territory above sea level. Two significant sites with polymetallic massive sulphide deposits forming today are known on neovolcanic ridges in the Manus Basin. Their high precious metal contents have led to renewed interest in the issue of exploiting seafloor mineral deposits. The prospects of finding other, possibly larger deposits in the region appear substantial. This paper reviews current data on seafloor deposits in Papua New Guinea (PNG) and raises some issues relating to future commercial exploration and mining of the sea floor. One of the known PNG deposits could become a prime candidate for the trials needed to develop technology, establish costs, and minimise environmental impact.

Jan 1, 1994

The initiation of cast Pentolite primers by detonating cord has been examined by the combination of two different experimental techniques with computer simulation by the finite element hydrodynamic code DYNA2D. In the first type of experiment, the cord/primer system was placed in a water aquarium, and photographed using a high-speed image converter camera. This highlighted the emergence of the detonation front through the primer surface and the generation of shock waves in the surround- ings. Numerical simulation was used to interpret the experimental record, establishing where the cord had induced buildup to detonation inside the primer. The second experiment used the plate dent test, where the primer was placed in contact with a block of metal (here aluminium), with the resul- tant dent in the metal surface being a measure of primer output. Detailed numerical simulation of this test confirmed that the observed dent was caused by the development of a complex series of shock waves inside the Primer.

Jan 1, 1988

Operating metallurgists spend a significant part of their time running plant trials to compare two or more conditions in order to improve the process, such as a new reagent, flow sheet or piece of equipment. The best way to conduct such a trial is as a paired experiment when testing two conditions (eg 'old' and 'new') or a randomised block design when testing more than two conditions. These experimental designs should always be preferred over alternatives if their requirements can be met, because they block the effect of uncontrolled variables ('covariates') and are the most statistically efficient, ie they will lead to the required level of confidence in the outcome faster than other methods. Sometimes, however, it is not possible to switch condition easily, which is a prime requirement of these methods. In such cases the only option may be to switch condition once only, and compare the process performance before and after the switch. Examples are testing grinding media, large equipment, or long residence time processes such as leach trains or CCD thickeners. This paper considers some data analysis methods to deal with this situation. Modelling with intervention analysis (IA) uses regression models with a dummy variable to indicate the presence or absence of the test condition. IA with a time series model ensures that the residuals are uncorrelated. IA with a process model helps to deal with the problem of covariates. The reference distribution is a method free of any statistical assumptions but is less powerful than the other methods. Cusum charts are a helpful visual aid to interpreting time trends. A combination of these methods can help improve the confidence in the final decision. None are as good as a formal experimental design such as a paired trial.

Jan 1, 2008

An intensive safety campaign at Mount Isa Mines Limited from 1956 to 1966 saw the lost time accident frequency rate fall to half its original level. A review of the safety programme was carried out in 1967 and in 1968 the Five Point Safety System was introduced. The seven years since its introduction have been years of significant achievement both in production and safety. Improving safety is a fundamental part of Mount Isa Mines Limited's policy and this system has been a major tool in implementing that policy. To be successful personnel need to be prepared and trained for its introduction and subsequently counselled on its use. A carefully prepared programme is required to phase in various aspects of the system and to make use of complementary steps. The system has been a success and it is anticipated that the continued drive to improve the use of principles of the system will further improve safety. It is hoped that this paper will be of value to those personnel concerned with industrial safety in Australia.

Jan 1, 1975

By Carter NB

A statistically-designed experimental program has been used to study compositional and processing variables which influence the development of strength and reducibility of iron ore pellets. The effects of chemical composition and processing variables were investigated by indurating laboratory-made green pellets, of known composition, under approximately isothermal conditions in a pot- grate simulator. Some findings from a six- variable study are summarized in the form of contour diagrams and emphasize the importance of interactions between the variables. Production of strong, highly reducible pellets is possible over a considerable range of combinations of temperature and firing time. Abrasion index (AI) and cold compression strength (CCS) improve as both these variables increase, but reducibility (R) declines, so a compromise is required. When the lime level is too low to form enough slag for bonding, the AI and CCS may be inadequate. Larger additions of lime tend to improve AI and CCS, with only slight effects on R. Finer grinding of the balling feed (i.e. higher Blaine index) tends to improve Al and CCS without

Jan 1, 1980

By J Poniewierski, Varcos D

Efficient blasting requires constant vigilance with respect to the actual layout being used in the field. Objective measurement techniques are required in laying out a pattern as the 'by eye' or 'thumb suck' methods cannot guarantee consistent results in layout. Erratic blast results are the consequence of such an approach. In a case study at Sons of Gwalia mine, it was demonstrated that incorrect front burdens had a snowballing effect on otherwise carefully laid out blasts, resulting in both excessive amounts of boulders caused by preconditioning of bench fronts and tops, and tight digging. Both problems caused lower excavator productivity and excessive excavator damage, as well as making it difficult to set out subsequent blasts correctly. Several field measurement methods are available to aid in determining correct blast layouts and one is described in this paper.

Jan 1, 1994

By Marshall K. I

THE problem of satisfactorily eliminating the fumes and dust which are unavoidably produced in various metallurgical and manufacturing industries is one which has received considerable attention in the past, and has been the subject of much investigation and research. The solution of this problem was urgently desired for two reasons, the principal one being the fact that a considerable percentage of the total process losses in many industries was represented by the commercial values of the fumes and dust that escaped from the stack.The other reason is that, in some instances, the emission of the matter is regarded as objectionable. Various methods have been designed with a view to solving the problem thus presented, and the latest development that has beendesigned is the process of electrostatic precipitation. Continued investigational and developmental work with this process has already demonstrated its applicability to many industries, and new uses to which the process can be put are being opened up. Its use is already widespread, and the economic success that has attended its application in most instances would indicate that its use will become more general in the future.It has proved its ability to treat gases over wide ranges of temperature, and has successfully handled various types of fumes whose chemical characteristics differ very considerably. In many processes it has now come to be regarded as standard equipment.HISTORY OF ELECTRICAL PRECIPITATIONThe first recorded observations on the influence of an electrified insulated wire on gases containing solid particles in suspension was made as early as 1824 by Hohlfeld, in Leipzig. He found that, if he electrified a wire hung in a bottle filled with smoke, the smoke cleared rapidly, and a deposit formed on the sides and bottom of the bottle.

Jan 1, 1923

By Scott IR

In stratigraphic orebodies, estimation of footwall and hangingwall location is often of more importance than grade estimation. Contoured grade estimates often produce smeared boundaries and the use of accumulations and thicknesses as variables re-introduces the original problem: location of the point at which the estimate is to be made. The paper introduces statistical and geostatistical techniques for the solution of the problem and illustrates the techniques with a case study from Mount Isa, one of the world's largest producing silver-lead-zinc deposits. Solutions for calculating variograms in orebodies of variable dip, strike and plunge are presented together with relative variograms for individual metals, metal accumulation and orebody thickness. Optimal methods for hangingwall and footwall location are introduced and illustrated with an example. Orebody boundaries are then kriged after which individual metal grades are kriged within the estimated boundaries. The boundary estimates are compared with manually interpreted boundaries and known boundaries in mined-out areas. Grade and tonnage estimates are compared in mined-out areas.

Jan 1, 1986

By T Walsh, S R. Mudnuru

The development of lithium-ion batteries, coupled with the global trend towards electrification of transportation, has led to a dramatic increase in the demand for lithium. The production of lithium from hard rock ores is increasing, and flotation has proved to be an effective means for the beneficiation of many pegmatitic lithium ores. Clariant Mining Solutions has developed a range of novel collectors for the flotation of spodumene and other lithium ores, and this paper presents examples of some of the most recent developments. Fatty acids are the typical collectors for lithium flotation, however the grade and recovery achieved with these collectors is often below the desired level. There are also some significant drawbacks associated with the use of fatty acid collectors, such as the formation of calcium soaps which give rise to filtration problems and the need for acid washing. Several FLOTINOR products have been developed as alternatives to fatty acids. These products offer equivalent or better metallurgical performance at significantly lower dosages than fatty acids. This offers benefits to the flotation circuit as well as potentially reducing the issues associated with downstream processing of the concentrate.

Aug 24, 2022

By Bothe C

Froth flotation processes use different surface properties of the minerals to be sorted. In an aqueous environment the hydrophobic mineral attaches selectively to air bubbles and is lifted to the surface of a separation vessel, while the tailings settle towards its bottom. Besides the surface properties, the hydrodynamic conditions play an important role. With respect to the hydrodynamics the flotation process can be divided, for simplicity, in two sub-processes. The attachment of hydrophobic particles to air bubbles, the so-called mineralisation, demands a large number of collisions and therefore high turbulences. The phase separation however needs a deterministic movement of both the particle-bubbles-aggregates and the tailings particles and therefore a quiescent flow field. The optimisation of the overall process requires a separation of both sub-processes, especially when fine particles have to be sorted. In conventional mechanically agitated flotation cells both sub-processes take place in the same turbulent volume. For this reason they suffer from a decreasing selectivity with decreasing particle size. In flotation columns the mineralisation of air bubbles and the phase separation are performed in a quiescent environment. This results in high concentrate grades and at the same time in a very slow attachment kinetics, which must, especially for fine particles, be counterbalanced by a long residence time of the slurry.

Jan 1, 1993

In 1985 BMR assessed Australia's economic demonstrated resources of mineral sands as follows: rutile 8.0 Mt, ilmenite 41.4 Mt, zircon 11.5 Mt, and monazite 229 000 tonnes. These resources are located along the east coast of Australia, in the southwest corner of Western Australia, and in the Eneabba region, north of Perth, WA. However, over 40% of Australia's rutile and zircon resources, particularly those on the east coast, are presently not available for mining because of environmental considerations. As well, east coast ilmenite has been considered unsuitable for use by sulphate route pigment producers because of its relatively high chrome content. World demonstrated resources of rutile and zircon are estimated by BMR as 29 Mt and 38 Mt respectively. Demonstrated resources of ilmenite amount to about 1 billion tonnes. These occur predominantly in hard rock deposits in Norway, Canada, USSR and China, as well as alluvial deposits in Australia, South Africa and India. Quantitative data for world monazite resources is sparse. However, world production of rare earth oxides is now mainly from bastnaesite, a hard rock resource. Australia is presently the world's principal producer of rutile and zircon, and also provides a major share of the world's ilmenite. With the expected increase in Australia's rate of output of these commodities, combined with restrictions on mining along parts of the east coast, its position could diminish substantially over the next 25 years.

Jan 1, 1986

By J E. Everett

Maximising ore tonnage at a selected target grade requires that appropriate ore identification criteria be established. Iron ore mining block models may consist of many millions of estimated blocks, each block corresponding to the selective mining unit (SMU), with grade interpolated from drill hole data. Each block can be considered as a potential ore candidate. Analysis of such a huge database can require large computational resources, especially for sensitivity analysis requiring multiple computations. However, an alternative streamlined approach is possible, where the data are compressed to an appropriately smaller and representative subset. The consequent data reduction not only makes it feasible to consider the simultaneous analysis of multiple pits but also considerably speeds up computation, enabling sensitivity analysis of the potential ore tonnage as a function of the required grade. Ore identification criteria can be successfully established using appropriately chosen reduced data comprising less than one per cent of the blocks. The ore identified is virtually indistinguishable in tonnage and grade from the ore that would be selected using the entire block model.Two methods of data reduction are tested: sampling (using a proportion of unaltered blocks) and binning (consolidating groups of blocks to a single average grade). The source blocks are first sorted (such as by location, analyte grade, principal component score, random order or value) before sampling or binning. In this study, the sorting options considered were by location and Fe grade. The effectiveness of each method was evaluated using the block model subsets to select the maximum tonnage of ore at a specified target grade. Block model data from an anonymous Pilbara iron ore project with about one million blocks averaging 1.132 kt were used. The blocks are from multiple resource models, to be blended to a single product. Sampling is shown to be superior to binning because sampling preserves the full variability while binning, although matching the mean block grades reduces their variability.It was found that the appropriately sampled data sets (sorted by location) gave results virtually identical to the results for the full data set, even when the samples comprised less than one per cent of the original blocks. The reduction in computer time to identify maximum tonnage at a specified grade was approximately proportional to the sample percentage. The increase in computation speed greatly facilitated sensitivity analysis. A sampled data set of one-eighth the total block model was used to investigate the effects of changing each of the component grades around the original grade specification. The results of this sensitivity analysis are discussed, and illustrate the potential benefit of carrying out sensitivity analysis in determining feasible and marketable product grades.CITATION:Everett, J E, 2015. Block model data reduction and sensitivity analysis, in Proceedings Iron Ore 2015, pp 263–270 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By M Nehring, M Kizil, P Knights, A Mousavi, F Sotoudeh

A cut-off grade is used to distinguish an economically viable block of ore from non-economical ones in mining operations. In order to obtain a high Net Present Value (NPV), a strategic and precise determination of cut-off grades (mill feed/marginal, marginal/waste) is required. In recent years, the significant depletion of feed grades and increasing mining operating costs have affected the viability of new and existing mining operations. Hence, the introduction of a pre-concentration system to process ore before sending it the main processing plant has gained increasing attention for its potential improvements in resource exploitation processes, mineral processing, energy consumption and environmental impacts. The primary potential advantage of implementing a pre-concentration system is the improvement of resource utilisation and increased reserves as a result of a reduction in cut-off grade. The objective of this paper is to present a new cut-off grade method, which can be used in the presence of a pre-concentration system for underground metalliferous mining operations. The results of this study illustrate the potential economic benefits of using a pre-concertation system prior to a mineral processing operation as a result of the reduced cut-off grade and increased NPV.

Nov 10, 2020

By Tapp B. A

The minerals industry in Australia is currently regarded as the country's economic saviour; the bastion of economic security. As Fitzgerald (1974) stated, 'Australia's natural endowments in minerals are the envy of most countries of the world'. As a result the proposed new mineral developments are on a scale that hitherto in the sixties would have been completely unenvisaged. It is reported that Australia is poised on the verge'of a sixteen billion dollar mining-based investment boom: a boom that will see Australia dominate the energy export field, the mineral processing field, and create the 'coal dollar'. This growth scenario has many inherent dangers, and it is the authors' contention that these should be carefully considered before further development proceeds. Two of the major problems related to the mineral industry growth scenario are the predictability of the future metal market, and the energy cost of mining. The latter problem is the one discussed here. The mining-mineral processing industries in Australia currently use about 36% of Australia's primary energy

Jan 1, 1980

By G Pattenden, R Hargreaves, P Pettit

"Even with the cyclic nature of mining, when it comes down to it, the bottom line is that whatever direction the commodity market is going there is always a desire to improve the economics of an operation in order to deliver a greater return to investors. Adapting to market pressures by introduction of an operational process change can often have a downstream impact. What may be less obvious is that reconciliation can play an important part in measuring the effectiveness of many operational changes. Through the adoption of best practice reconciliation and related comparisons, it is possible to measure the impact of changes across the mine value chain and identify variability that may have been introduced. Using analytical business improvement tools, examining and monitoring planned changes can be crucial in understanding whether the introduced changes have been effective and whether they have provided the expected result. Using several case studies, the authors will highlight the benefits provided by modern business intelligence tools, which can provide data validation and accurately report data trends related to both planned and unplanned change events.Citation:Hargreaves, R, Pattenden, G and Pettit, P, 2016. Measuring the Effectiveness of Change through Best Practice Reconciliation, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 71–83 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By Sen A. K

The Chiria Iron Ore deposit falls within the well-known Horse-shoe-shaped Singhbhum-Bonai-Keonjhar belt in India, where most of the deposits supplying ore to various steel works of Steel Authority of India Limited (SAIL) and Tata Iron and Steel Company (TISCO) are located. With an estimated reserve of about 2000 million tonnes of ore (at 55 per cent Fe cut-off) spread over four contiguous blocks, it is the largest iron ore deposit in India and one of the largest in world. The present study is confined to only one of the four blocks of Chiria viz North Block, comprising an area of 2.11 km2. `Corporate Plan 2005' of SAIL envisages development of a large open cast mine at Chiria to meet its enhanced requirement of iron ore by 2001-02 AD.

Jan 1, 1995

Western Australia has often been referred to as the fly-in, fly-out capital of the world. Fly-in, fly-out is a commonly used practice in Western Australia due to the geographic size and isolated location of the vast resource projects. In the State today, approximately half of all resource sector employees operate on a fly-in, fly-out basis, with a minority utilising drive-in, drive-out arrangements. fly-in, fly-out arrangements are generally beneficial from a sustainability perspective, delivering significant economic, social and environmental benefits to regional communities, the State and nation as a whole. Skills shortages and labour supply issues mean that the industry will be required to discover new ways of attracting and retaining employees, one of which is the adoption of fly-in, fly-out work journey arrangements. By 2015, the minerals sector in Australia will need to employ 70 000 more employees than it currently employs to achieve predicted increases in output. Of the 70 000 additional employees required, 42 000 will be required in Western Australia, almost 15 000 in Queensland and approximately 5000 in both New South Wales and South Australia. The fly-in, fly-out lifestyle as a preferred method of employment should be recognised as a valid lifestyle choice by all members of the community, offering a profound improvement in the quality of life for large numbers of employees and family members. It should be acknowledged that whilst fly-in, fly-out is a preferred option for many companies and their employees, individuals who make a choice to engage in fly-in, fly-out must balance the difficulties associated with the work û isolation and separation from family and friends û against the economic and lifestyle benefits that the work offers. This paper aims to illustrate the significant steps that the resources sector has taken to facilitate the fly-in, fly-out choice by ensuring that the commute option is a safe, attractive and manageable work journey arrangement.

Jan 1, 2008

Discontinuities often have a very detrimental effect on the stability of mine highwall faces. The west wall of the Muja open cut is remarkable for the number and variety of discontinuity sets which occur over a relatively small area. To-date 14 separate structural domains have been identified over an area measuring approximately 560 m by 120 m.The structural domains have been grouped into four structural assemblages on the basis of their angular relationships to each other and to regional folding and faulting. The distribution of these structural assemblages appears to be erratic and no controlling factors have been identified to explain or predict them other than in the most generalised terms.

Jan 1, 1993

The completion of the Hot Strip Mill at the Port Kembla works of Australian Iron & Steel Ltd., makes possible the production of steel plates and wide strip of a quality and in quantities not possible previously in Australia, and will also enable the production of tinplate to be undertaken in this country.The site chosen for the mill was a mud fiat underlain by a hard stone bottom at 5, to 801 feet below the surface; and a total area of one hundred acres was reclaimed to a level of 20 feet above the original surface.Three adjoining buildings were constructed to house the slab receiving yard, mill equipment and electric drive, together with the plate finishing line.After slabs have been heated to 2250°F at a rate of 90 tons per hour, they are transferred to the vertical scale breaker which is the first stand in the hot roughing mill. Here the primary furnace scale is first cracked and then blasted off by high velocity water descaling sprays.The next stand is the horizontal scale l;Jreaker, where any remaining primary scale is broken and then blasted off. After descaling, the slabs pass to the broadside mill, where short slabs are turned and rolled on broad side for wide plate.The next step is a slab squeezer which squares up the edges after broadsiding ready for the reversing mill. This is the finishing stand for plate and the last roughing stand for strip, which then passes to the finishing mill.The hot strip finishing mill consists of six stands with a maximum finishing speed of 2,230 feet per minute. Strip is cooled for coiling by water sprays on a hot run table and then coiled on a mandrel type downcoiler, from whence coils of hot strip are weighed and transferred by conveyor to the coil storage building.Plates are transferred from the reversing mill to the plate finishing line where operations consist of levelling, inspection, branding, cutting to width and length:INTRODUCTIONDue'to the increasing production of cars, refrigerators, washing machines and similar consumer goods in Australia, together with the increased requirements of galvanised iron...

Jan 1, 1956

By Aspinall T. O, Just G. D

Computer software systems have been developed to assist in a wide range of specific mine planning and scheduling applications. In selecting appropriate systems for any mining operation it is apparent that certain features have particular advantages for each mine site. The ideal solution to this problem is to select a range of systems which best relate to sections of each mining operation. This approach raises potential data linking difficulties where output from one system is incompatible with input requirements for other systems. A study at the University of Queensland investigated the problems related to the integration of a number of mine planning and scheduling software systems. The project used data from large scale coal strip mining operations in Central Queensland. Two major computer packages used extensively in the study were the SURPAC mine planning and XPAC mine scheduling systems. Dragline and truck and shovel operations were analysed in the project. Results of the work have been directly applied at the mine site to assist current strip design by effectively automating the design procedure. This enabled sensitivity studies to determine the effects of changing dragline working levels and varying pit dimensions. Coal blending studies and procedures to optimise operations have been investigated using linear programming within a spreadsheet software application. Output from the SURPAC and XPAC programs was directly linked to the linear program for this analysis. The simulation program GPSS/PC was also used in a similar manner to assess optimisation parameters.

Jan 1, 1992