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By Moxon NT, Torrace AC

The detonation pressure of an explosive is a function of its density and its velocity of detonation (VOD) and relates directly to the degree and manner in which the explosive loads the surrounding rock. The suitabil- ity of an explosive to any particular situation is determined not so much by the total energy released but more by the rate at which it is released. As the science of rock blasting advances it is becoming economically more important to quantify explosive performance, particularly with respect to quality control and fragmentation. As part of a major explosive user, BHP Central Research Laboratories have developed a number of tech- niques to determine the detonation characteristics of explosives. These include a method of continuous velocity of detonation measurement based on the SLIFER principle. This not only enables the VOD of the explo- sive to be determined, but also has the versatility to allow factors such as under priming, slow run up, the effect of water, variable energy load- ing and the velocity of the shock wave in the stemming to be assessed. Multi point VOD systems have also been developed for more routine appli- cations. With a minor modification they can be used to determine the absolute delay of detonators accurately and economically. Direct deto- nation pressure measurement methods have also been developed based on piezoresistive techniques. Future developments include the incorpo- ration of all the above techniques into a single, portable package, allow- ing easy use on the mine site.

Jan 1, 1988

By Blain CF

For all mineral resource-based companies, it is important to reach the right balance of investment between acquisition and exploration to allow the best chance of achieving long-term corporate goals. The Broken Hill Proprietary Company Limited (BHP) provides an excellent example of success from generative exploration and supports the belief that exploration can be justified, not only in terms of investment criteria, but also because it is essential to a company wishing to build a dynamic profitable growth path based on world-class deposits as cheaply as possible. BHP was incorporated in 1885 to mine a lead/zinc/silver discovery at Broken Hill. The Company has since gone through a steel development phase (1911-1965) and is now in a major phase of growth partly based on exploration success. This third phase was marked by decisions taken in the 1950's to search actively for mineral and energy resources above and beyond the requirements of the steel industry. The commercial successes of this period have been Bass Strait oil and gas, Groote Eylandt manganese, Deepdale iron ore, Gregory coal and Carnilya East nickel. In total at least 22 new resource discoveries have been made in the last 25 years, of which 11 have been developed and several are undergoing feasibility studies. A financial analysis shows that the real value of the returns seeded by discovery covers the real exploration cost many times over. Moreover, the major discoveries have had a spectacular impact on the growth and development of the Company. BHP's present exploration effort is directed towards geological targets which most frequently meet attractive financial criteria and also promote diversification from steel-related earnings.

Jan 1, 1986

The development of present methods of pillar extraction has evolved from the very earliest of hand mining operations which were limited in scope by venti- lation and transport considerations. Conservation and safety considerations also have led to the current shortwall operations with conventional equipment and powered supports. The shortwall methods have had significant effects on safety, costs, con- servation, flexibility, and other aspects of pillar extraction. The present stage falls short of the ideal but is some guide to prediction in what direction may lie the ideal methods for the future.

Jan 1, 1974

By Thompson IR

This paper describes a Client Consultant Relationship and shows how an engineering team created an environ- ment which fosters the development of good, economical and sometimes unique solutions. A major factor in establish- ing this environment was the Client's instruction to the Consultant to "propose solutions which, in the Consultant's considered opinion, best satisfy the needs of the project - not necessarily solutions which reproduce methods adopted elsewhere in the past." The Consultant's experience in other projects and disciplines outside mining has contributed by providing a cross- fertilisation of ideas. The team approach also allows the Client's expertise to be applied positively throughout the design process. These factors and the Client's foresight in providing adequate time for planning, allow the Client-Consultant Team to apply sound fundamental engineering in developing effective solutions.

Jan 1, 1975

The AJ Parker Cooperative Research Centre for Hydrometallurgy is the focus of a world-class effort in providing technical solutions to the minerals industry. The 85 FTE staff are drawn from the CentreÆs five joint venture research partners comprising universities (Curtin, Murdoch and Qld) and government research agencies (CSIRO and WA Dept of Industry and Resources). There are also 12 industry partners, representing most of the leading mining companies in the world. Around 45 postgraduate students, mainly PhDs, make a significant contribution to the research effort. Total annual expenditure on R&D is around $17 million.Hydrometallurgy activities encompass both fundamental and applied research across the alumina, gold and base metal sectors. The Centre is now growing its client base into overseas markets, particularly North America, South Africa and Europe. Quality, strategic R&D by the Parker Centre is seen by the industry as an attractive investment. A recent survey of the industry revealed an estimated ten-fold return based on direct costs of research to the client. In addition, the Parker Centre has a strong commitment to education of postgraduate students wishing to enter the mining industry as well as providing specialist courses for those technical professionals already employed in the industry. The wide range of employment opportunities in the mining industry is reflected in the diversity of the disciplines amongst the CentreÆs research team, eg extractive metallurgy, chemistry, biotechnology, physics, engineering, molecular modelling, microscopy, geology and computational fluid dynamics. How does an atomic force microscope and molecular modelling improve our ability to control gypsum scaling or understand crystallisation of alumina in a Bayer plant? Can a biologist contribute to the problem of the slow leaching of copper from chalcopyrite? Why are computational fluid dynamics and lasers the basis of understanding how to make thickeners work more efficiently. Can you combine a PhD or Honours degree with industry experience? What is crud and why is nickel stressed? These are typical examples of the CentreÆs research activities and demonstrate the contributions of its multi-disciplinary teams which keep the Australian mining industry at the cutting edge of advanced global technology.

Jan 1, 2003

In todayÆs demanding business landscape continual change and technological advancement is a given. With these changes there is now, more than ever, a need to ensure sustainable growth in respect of value protection and value adding whilst meeting the pressures and expectations of the societies in which we operate. Traditionally the management of safety has been a very reactive activity in the business, in some cases seen as an irritation and a disruptive process that demands a focus on preventing reoccurrences. This in turn has focused the measurement of safety performance on a range of lagging indicators û æafter the effect managementÆ. Gaining and maintaining a licence to operate is crucial to a sustainable business but as a prerequisite, organisations need to have a demonstrable ability to manage the safety of their people, as well as mitigating the people risk associated with the business activity. A major focus in the last decade has been on the implementation of enterprise risk management programs, where risk becomes embedded in all business systems and processes and the organisationsÆ genetic make up is programmed to analyse and integrate risk management into all facets of the business activity. The management of safety should be no different. One school of thought argues that there are no new accidents, but rather our inability to learn from the past. Others believe that as long as we have an appetite to achieve the unachievable, we will have to continue to push the boundaries, our safety comfort zones and inevitably take risks. Single reliance on highly evolved technical systems, elaborate processes, highly skilled people, safe equipment and safe work environments have shown one thing û they are not sustainable in providing adequate coverage in the business. In analysing a range of factors associated with some of the worst catastrophes of the 20th century, it can be suggested that they were in fact predictable and inevitable and that an integrated approach underpinned by sound risk management systems could have determined a different result. The key to a sustainable approach in the management of safety requires us to look at a multitude of aspects that collectively allow the performance of an organisation to be predictable. To have certainty in the business activities it is necessary to have controls in place that will mitigate the risks normally associated with unwanted events. It is ensuring that human factors effectively contribute to monitoring the planned approach and being able to safely adjust to any variability. In essence this is having the ability to proactively plan for the longer term. The sentiments articulated by organisational leaders echo that safety management is good business. Surely then a good business is a sustainable business, and a sustainable business is one that provides lasting benefits to its stakeholders.

Jan 1, 2006

By Qi P. H

Gold dissolution can be achieved with a number of complexing ligands, all with varying degrees of stability. Processes based on the use of halogens have been known for many years. Beside providing the necessary complex- ing role, the halogens under the appropriate conditions are very effective oxidants for gold. Of the halogens, the gold iodide complexes are the most stable in aqueous solution. Iodine can establish the desired oxidation poten- tial for oxidizing gold, and unlike chlorine and bromine, the oxidizing potential of iodine is mild enough to avoid the oxidation of impurity constituents like metal sulfides. A series of experiments to investigate the fundamental electrochemistry of gold in different halide solutions was performed. Cyclic voltammograms of gold in the presence of 10-2 M chloride, bromide and iodide, respectively show that for a given potential the rate of oxidation is much faster in iodide solution than in either chloride or bromide. An overlay of linear sweep voltammograms for the anodic oxidation of gold in iodide and the cathodic reduction of iodine species on gold provides an effective method for examining the dissolution of gold in iodideftodine solution. The dissolution rates obtained from both electrochemical and actual leaching results are compared. Optimum leaching conditions are analyzed in terms of the iodide/iodine concentrations. Conceptual processes for the recovery of gold and iodide and the regeneration of iodine are discussed.

Jan 1, 1991

By B Tadesse, L G. Dyer, B Albijanic, M Jung

The presence of high concentrations of dissolved ions in groundwater, sea water or recycled water may alter the water structure, particle surface wettability and colloidal interactions between bubbles and particles and can have a significant effect on mineral flotation. While the impact of water quality on the flotation of precious and base metal minerals is well established, no relevant published study exists currently regarding the effect of water salinity on the flotation of rare earth bearing minerals. This paper attempts to quantify the effect of water quality variation on flotation recovery and grade of rare earth minerals and gain an understanding on which ions existing in saline water affect flotation behaviour. Specifically, it is aimed at investigating the effects of water quality on the flotation of monazite in the presence of cations such as Ca2+, Mg2+, K+, and Na+. Flotation tests, zeta potential measurements, and adsorption tests were performed to explain the flotation behaviour. It was found that monovalent ions such as Na+ and K+ have negative impact on rare earth minerals recovery and grade. The result of single mineral flotation tests showed that the floatability of monazite was significantly depressed in the presence of Ca2+ and Mg2+. The result of single mineral flotation test showed varying depression levels in the presence ions in the order of Ca2+ > Mg2+ > Na ~ K.

Aug 24, 2022

The metallogenic belts of the Central Andes (iron, porphyry copper, polymetallic and tin) are genetically related to an eastward migrating magmatic arc. The polymetallic belt of the Bolivian Altiplano formed during Miocene arc broadening and lies in a critical position for understanding the genesis of this zonation. It is penecontemporaneous with parts of the copper and tin belts, and shares many characteristics with them. The differences between the belts result from contrasting volcanic and feeder stock geometry, depth of erosion and country rocks, and are not due to variations in magma chemistry, age or Benioff Zone depth. Polymetallic mineralisation in the Altiplano is epithermal in style and mostly related to flow-dome volcanism. The intermontane basinal setting precludes deep erosion to expose the epizonal feeder stocks and predicted porphyry copper mineralisation. In contrast, erosion of the less abundant stratovolcanoes of the Altiplano-Puna and Pampean Massif may expose contemporaneous Miocene porphyry copper mineralisation in subvolcanic stocks. The tin belt is coincident with the Paleozoic fold belt of the Eastern Cordillera. The occurrence of minor tin in Altiplano epithermal deposits hosted by Paleozoic sediments, and the persistence of tin mineralisation in the tin belt over 350Ma, suggests that Paleozoic sediments are the source of the tin.

Jan 1, 1987

By Fallins J

THE John Darling Colliery, owned by The Broken Hill Proprietary Company Limited, is situated 12 miles south of Neweastle, NSW and about 1 mile from the ocean. The area of the holding is approximately 10,000 acres, about half of which underlies the Pacific Ocean. The area was proved to be coal bearing by diamond drill boring: this method not only proved the coal to exist, but gave the depths from which could be calculated. It also proved the existence or otherwise of heavy faulting, which is a very important factor in the design of the underground lay-out of a mine. The location of shafts had to be carefuIly studied, and, before final selection, the following salient points had to be considered:Railway communications.Flood waters.Boiler feed water.Surface buildings.Probability of coal washing.Underground haulage arrangements.Lengths of roadways from a ventilating viewpoint.Before the shaft sites were finally selected, an underground design was prepared to determine the direction of the main drives in relation to the boundaries of the holding, and the of the coal seam: the latter, being an important factor in this particular locality, was ascertained by a geological survey of rock outcrops in the neighbourhood. Size of shafts was the next subject for consideration. This was determined by output, number of seams to be worked, amount of ventilation required, and, on...

Jan 1, 1930

By Ross R

Although mining is an old industry its management is quite a new science, and its complications are now being recognised as demanding expert knowledge in many branches of technical and professional education. Not the least amongst these isaccountancy, for probably its most important problem is "How to control the expenditure." Unlike most businesses a mining company stands almost entirely in the light of a purchaser in the world's markets, and not as a seller, except say for product so the established and perfected systems of modern industries cannot be adopted for mining purposes. For this reason it has been left for late years to consider the matter seriously, and now a number of well-managed concerns have devised costs systems to suit their own requirements.Very little, however, has been published and even that is disjoined and difficult to make use of. Some of the costs systems in vogue, although elaborate and imposing, are not of very great value for keeping check on wasteful expenditure, or for displaying the commercial effect brought about 'by any particular change in practice, or by an addition or alteration to a portion of existing plant.

Jan 1, 1911

By Ault A. R

The recent modernisation program at the Risdon electrolytic zinc smelter of Pasminco Metals - EZ (PMEZ) inyolved significant changes to the composition of cell electrolytes. The most significant were increased acidity and sulphate level, a reduction in Co level, and the replacement of 2-naphthol in the additive mixture with licorice. In determining acceptable operating ranges, a relatively large number of industrial deposition tests under controlled conditions was required. The cathode zinc deposits so produced were examined in terms of overall appearance, crystal structure according to X-ray diffraction, and a micro-roughness parameter. Beginning with typical deposits produced in the presence of an excess of one of the addition agents glue or antimony or a mist suppressant (licorice or 2-naphthol), a simple classification system was developed. In this system, the deposits are divided into the following types: Doughy, Pinholed, Compact and Stressed. There was a weak correlation between deposit type and crystal orientation. In terms of ease of stripping, observations in plant operations showed that only Compact and Pinholed were consistently acceptable. Current efficiency was normally maximised by producing a Compact deposit. Process variables such as zinc concentration, temperature and the use of strontium carbonate were found to cause changes in deposit type if the reagent mixture used was unchanged. From the knowledge gained, guidelines were developed to allow glue and antimony additions to be altered to fit new circumstances. The simple classification system was first used to expedite recovery from undesirable morphologies and then to optimise individual cell units operated under substantially different conditions. It is believed that finer control could be exercised by determining the micro-roughness of Compact deposits. However, difficulties can arise if sudden, large deviations occur and go undetected. Suggestions are given for an improved additive control system. The classification system developed has been compared with published information in the literature, and good correspondence was noted suggesting a predictable relationship between short-term, laboratory deposition tests and observable phenomena in industrial electrowinning cells run under steady conditions.

Jan 1, 1993

By Grouhel P

Blasting performance is directly related to the characteristics and efficiency of the explosives used. The selection of the correct explosive for particular blast conditions and objectives depends on the ability to characterise the performance of individual explosive products. Techniques have been developed by the JKMRC to measure explosive performance and assess the impact of explosive performance on blast results. Studies conducted at a number of mine sites have shown that different types of explosives perform quite differently and that the performance of any particular explosive can vary significantly. The principal causes of these variations have been identified and detailed blast monitoring techniques, including the analysis of muckpile fragmentation and shape, have been used to quantify the effects of explosive performance on blast Results.

Jan 1, 1990

By KeBler H-W, Seeliger A

Vibration analysis for diagnosis of machines is a powerful instrument for condition monitoring. Especially for diagnosis of antifriction bearings various equipment and techniques have been developed and are available. The envelope analysis is the most reliable method for bearing diagnosis. Different bearing failures lead to different patterns of the envelope spectrum. Checking the amplitudes of characteristic bearing frequencies is mostly not sufficient for a reliable diagnosis. Therefore human experts compare the pattern of the spectrum with typical patterns of bearing defects. In this paper a diagnosis system is presented which imitates this action of human experts. Using a neural net the system not only distinguishes typical bearing defects but also detects unbalance, beating of disengaged machine parts and other kinds of machine failures.

Jan 1, 1995

By Singh TN

Rampura-Agucha Zinc-Lead deposit is unique as it is reported for the first time in the gneissic terrain with a rich oregrade quality of early to middle Proterozoic of Bhilwara supracrustal belt in the Precambrian of Northwest India. These sulphide ores are mostly confined to the graphite bearing Quartzofelspathic gneisses with intermittent bands of Calc-Silicate granofels and amphibolite. The ore and country rock mineralogy and their textural features are indicative of highly metamorphosed deposit and further the presence of marmatite and monoclinic phyrrhotite revealed high temperature environment of deposition.The present paper deals with some of the ideas about the ore genesis and petrographics of the associated rocks for Rampura-Agucha Zinc-Lead deposits of Bhilwara District (Rajasthan).

Jan 1, 1990

By M I. Pownceby, N Karimian, J R. Manuel, M J. Peterson

The CSIRO ore classification scheme for Pilbara ores was used as a reference frame to target recognisable ore types/textures with potentially elevated phosphorus content for detailed analysis. Particles of each individual ore texture were separated from a Brockman high-P ore and each class was characterised using methods including XRF, XRD, EPMA and synchrotron-based XAS. Results were then correlated with optical microscopy and hand specimen identification to establish any relevant associated mineralogical phases and/or textures. This represents a more systematic approach to identification of high-P ore components based on particle and goethite type and texture. The information can then provide the basis for more targeted P-removal strategies factoring in the relationship between particle/ore texture and phosphorus deportment

Sep 18, 2023

By Y Wan, L Liao

Organo-montmorillonites were synthesised by intercalating different amounts of dodecyl trimethylammonium bromide, cetyl trimethyl- ammonium bromide and stear trimethylammonium bromide into montmorillonite layers, and were used for the adsorption of 17b-estradiol in aqueous solution. The adsorption kinetics and thermodynamic of 17b-estradiol onto organo-montmorillonites and the effect of pH on the adsorption capacity of organo-montmorillonites for 17b-estradiol were studied. The adsorption isotherms at 20¦C, 35¦C and 50¦C were measured. Results show that organo-montmorillonite has a high affinity for 17b-estradiol. More 17b-estradiol can be adsorbed on to organo-montmorillonite and the adsorption is more rapid at a lower temperature. The montmorillonite intercalated with cetyltrimethyl- ammonium bromide with the amount equivalent to one times of its CEC has the highest adsorption capacity. For all organo-montmorillonites synthesised in this study, an optimum pH (around nine) for the adsorption of 17b-estradiol exists. Before this pH 17b-estradiol uptake increased with increasing pH. After that the 17b-estradiol uptake decreased with increasing pH. Simulation of the isotherms indicated that the adsorption of 17b-estradiol onto organo-montmorillonites is a spontaneous and exothermic process. Endocrine-disrupting chemicals (EDCs) are the focus of current environmental concern, as they can cause adverse health effects in an intact organism, or its progeny, subsequent to endocrine function. Most EDCs are man-made organic chemicals (industrial chemicals, crop protection products, antifouling compounds, pharmaceuticals and personal care products). In addition, EDCs can be naturally occurring in the environment (eg the natural female hormones estrone and 17b-estradiol). Therefore EDCs, especially estrone and 17b-estradiol, are ubiquitous in the aquatic environment receiving sewage inputs. Estrogen and 17b-estradiol are among the most potent of all EDCs and are sufficiently stable to survive present sewage treatment processes and are reactivated during those processes through deconjugation (Clara, Strenn and Saracevic, 2004; Zhang and Zhou, 2005; Fukuhara et al, 2006; Butler and Guilbault, 2006; Volpe et al, 2006; Ren et al, 2007; Zeng and Li, 2007). In comparison to traditional contaminants such as pesticides, the concentrations of the most potent EDCs are low, generally within ng/one range. The current sewage treatment processes have limited capacity in removing certain EDCs (eg 17b-estradiol, C18H24O2) It is therefore essential to install additional treatment processes to remove them from wastewater before discharge (Zhang and Zhou, 2005; Fukuhara et al, 2006; Lee, Jung and Kim, 2006). Adsorption is considered to be a possible way to remove EDCs from aqueous solution. Various adsorbents have been studied, including chitin, chitosan, ion-exchange resin, activated sludge, activated carbon (Clara, Strenn and Saracevic, 2004; Yoona and Westerhoffa, 2003; Zhang and Zhou, 2005; Fukuhara et al, 2006; Ren et al, 2007). Studies have shown that organo-montmorillonite has a high affinity for organic pollutants (Li, 1997; Zhu et al, 1998; Han et al, 2001). The aim of this work is to investigate the feasibility of removing 17b-estradiol from aqueous solution by adsorption onto organo-montmorillonite.

Jan 1, 2008

By Best R, Poulos H

This paper discusses the results of an Australian Coal Association Research Program project into the development of a routine analytical design method for roof support in underground mines. Simple design tools have been developed using a combination of elastic solutions, free body diagrams, and pile theory. An approach to the design of roof support in layered strata based on the ability of bolts to resist shear stresses is outlined. It is shown that pre-tensioning and angled installation are effective ways of increasing the effectiveness of bolts in such a situation. In highly stressed strata, macroscopic failure is predicted and a design based on the support of surcharged rock wedges is proposed. The methods are applicable to both coal and metalliferous mines.

Jan 1, 1995

By Komosa T

The increase in the proportion of sulphide ore treated by the gold mining industry has led to generally higher oxygen requirements. Additions of pure oxygen, hydrogen peroxide and in some cases calcium peroxide, have been proposed as a means of satisfying the oxygen demand and overcoming the problems from reactive sulphides in the ore. Current oxidant addition options and practice are reviewed.Laboratory oxygen demand tests are reported for a suite of ores to show some of the effects of pH and preaeration.Laboratory leach tests at high and low dissolved oxygen levels are reported on two of the ores with higher oxygen demands, and the results are assessed in terms of gold leaching kinetics, ultimate gold extraction, and cyanide requirements.

Jan 1, 1992

The history of the discovery and development of the Kambalda nickel orebody. is reviewed and the decision to process the Kambalda concentrates by the Sherritt-Gordon process at Kwinana is discussed. The Kwinana Nickel Refinery is described and the problems encountered in the first year of operation are Outlined.

Jan 1, 1971