Search Documents

The paper sets out the context for water and the challenges that have to be faced in the battle to alleviate global poverty. It acknowledges that the world has been blessed with abundant water but because of population and development pressures, and the projected changes in climate, avoiding serious water shortages in some places will be difficult. MiningÆs use of water is placed in context and the paper then considers the specific threats to the industry in terms of availability and price and the need to find mechanisms to deal with the issue of resource degradation caused by abandoned mines. Rio TintoÆs use of water is then set out and three examples are given of how different water challenges have been addressed. The paper goes on to consider each element of a water strategy designed to move Rio TintoÆs performance towards excellence. This strategy incorporates improved management procedures (policy, principles, standards and targets), performance enhancement (through use of the Rio Tinto Water diagnostic and technology changes) and working with others in the academic and NGO community who seek to address the same global issue.

Jan 1, 2003

By Chunbao Z, Zhenchuan Z

As known to the international mining sectors, Hunan province, called as ' Nonferrous Native Area ', is the main base of nonferrous metals Pro- duction in China. There are over 194 nonferrous mines in this province, most of them distribute over the basin of Xiangjiang River. The state of management of wastewater in Hunan's nonferrous mines is outlined.The experiences and economic benefit in the management and treatment of wa- stewater in Bofang and Mayang copper mines, and at Shizhuyuan polymeta- llic mine, are mainly introduced. It concludes with measures and recommendations for future management and treatment of wastewater in Hunan's nonferrous mines.

Jan 1, 1988

Ore textures in Australian BIF-derived ores are quite complex and have formed the basis for ore genesis models, which includes hypogene upgrading or supergene upgrading then regional metamorphism for the microplaty hematite ores and supergene upgrading for the martite-goethite ores. Despite a high level of ore texture knowledge, little is known about the spatial distribution of ore textures within deposits or their relationship to downstream processing. This paper describes a new iron ore texture classification system to better understand the vertical textural zonation characteristics of Australian BIF-derived deposits, the interpreted role of recent supergene upgrading processes on modifying primary ore textures and their implications for downstream mineral processing. The iron ore textural classification scheme presented uses textural groupings defined on the basis of similarities in mineralogy, ore texture, porosity, mineral associations and hardness. The scheme is non-genetic and has been successfully applied to deposits in the Pilbara, Yilgarn and Gawler cratons. The main ore texture groups include dense martite/hematite, microplaty hematite, microplaty hematite-goethite, martite-goethite, goethite-martite and goethite-rich. Each group can be further subdivided into physically hard to softer subcategories. The ore textural groups can be divided into those interpreted to be associated with primary replacement of BIF and secondary textures resulting from more recent modification by near-surface hydration or dehydration processes. A schematic vertical section through BIF-derived deposits consists (from surface) of detritals underlain by a carapace, both of which may have been eroded, followed by a hydrated zone with replacement of primary ore martite and microplaty hematite by vitreous goethite. The hydrated zone is underlain by 0.2 - 6 m thick zones of intense dehydration and textural infilling of porosity with hematite and hydrohematite. Immediately below the dehydration zone is a strong zone of leaching, where more porous and friable ore textures occur, followed underneath by a gradational contact with primary ore. Secondary supergene processes can impact on beneficiation with hydration and leaching resulting in more difficult density separations at the concentrator stage due to reductions in density differences between ore and gangue and loss of heavy media into pores. Supergene modification of primary BIF-derived ore textures can substantially change lump metallurgical properties, with hydration and dehydration favourably increasing lump yield but reducing resistance to thermal shock whilst leaching will give the opposing outcome. The lump properties of ore textural groups appear to be relatively consistent within and between the iron ore deposits examined.

Jan 1, 2002

I must tell you at the outset that I come to this conference deeply disturbed at the `role of Government in international dealings in mineral and energy resources'. I am disturbed by the confusion that now passes for policy. I am disturbed by the short- range view of critical problems taken by a majority of Governments. I am equally disturbed by the even shorter range of view taken by a growing army of industries. Many of them clamour for Governments to solve their problems in a specific way, with little regard for any other sector but their own-and with even less regard for the fact that every time a Government takes over some of their responsibilities they surrender some of their freedom. I would not say that longer range views don't exist. But I would say that they don't prevail at the present time. Instead, we are seeing the con- stant development of many policies for individual problems which don't tackle the fundamental causes. We must get back to basics without delay.

Jan 1, 1978

THE following notes simply sum up the writer's experience, which extended over a very busy period of some three years, dealing with wolfram ores and concentrates. The three methods for the estimation of tungsten that are discussed below are well known, but these results of their trials and comparison under technical conditions may be interesting. Method I. The routine procedure for the assay of rich wolfram ores or concentrates was as follows: Take 1 gram of finely-ground sample; digest with HCl and HNOs for about 2 hours, evaporating down to near dryness. To the remaining 5 cc., say, of liquid, add water, warm or boil for 1 to 1.5 hour, filter through a small filter paper, and wash the beaker and the insoluble matter with hot dilute HCl. It is best to keep the bulk of the insoluble matter (WOs, Si02, etc.) in the beaker at this stage. Then plaee a weighed porcelain dish under the filter funnel and wash the beaker and the filter paper with successive small quantities of strong NHOH, finally bringing all the insoluble matter on to the filter paper, and collecting the ammoniacal filtrates in the porcelain dish (S). Then place the filter paper with the insoluble matter in a porcelain crucible, dry and burn off the paper, cool, and brush the contents of the crucible on to an agate mortar, grind it to flour, and brush this back to the original beaker without loss. In the absence of draughts this can be done safely. Re-treat this residue with' acid and ammonia as above, running the second ammoniacal filtrate into the previous porcelain dish, which in the meantime has been heating on a water-bath.Finally evaporate to dryness on the water-bath the combined ammoniaeal filtrate, and then heat gradually to a red heat over a Bunsen burner, cool, and weigh. Then the contents of the porcelain dish give the WOs (tungstie aeid) direcvly (5).The final filter paper and insoluble matter may be ignited in a porcelain crucible, thus giving the "insoluble matter." If the ore...

Jan 1, 1922

This report will differ slightly from the traditional scientific and technical discussions given at this type of conference. It will focus on the personal experiences and choices that I undertook when deciding on my graduate position and location after completing university studies. Throughout the duration of my course I had experience in both fly-in, fly-out operations in the Pilbara and residential operations in the West Australian Goldfields. These experiences, though limited, allowed me to explore the two different methods and their pros and cons, and consequently to make my choice for graduate employment. Throughout the duration of my degree I believed it was important to gain a basic understanding of the two methods, focusing on lifestyle and personal interactions. The decision that a residential site suited my personality and lifestyle then allowed me to refine my job applications to a more specific list of mine sites and companies, resulting in a residential position with BHP Billiton at their Iron Ore operations in the Pilbara, Western Australia.

Jan 1, 2005

By Marton A

The Readymix Group have a Quarry Improvement Program - 'Building in Quality (BIQ) which has many parallels to the ICI Explosives' total quality management - 'Quality Improvement Program' (QIP). Both companies have for some time recognised that the 'do it right first time' principle means less wasted effort and materials, that efficiency breeds profitability and so actively promote the quality culture. To install the principles and generate the culture requires considerable commitment and effort from the top down and invariably spreads to the suppliers and sub-contractors. Understanding the component processes involved with the quarry operation, analysis of those processes and gaining a breakdown of the cost of non conformance then allows the astute quarry operator to make the necessary changes to improve the process to realise profits. This paper outlines the steps in such a process and the profitable outcomes of the commitment to continuous improvement at the Nickol Bay Quarry.

Jan 1, 1994

By E Holloway

The optimisation of an open pit mine can be broadly split into two stages, the first being the ultimate pit optimisation (and subsequent stage designs), and the second being schedule optimisation. Macroeconomic uncertainty clearly impacts on both however interrelationships do also exist. Generally, the opportunity exists for the ultimate pit to be revised during each planning cycle, however when this reprieve is removed the uncertainty for the underlying business increases. As one example, the introduction of an in-pit waste dump can be seen to significantly limit the option to revise the ultimate pit. When in this situation there are two potential risks that present: (i) the long-term price used for the ultimate pit selection is optimistic, and too large of a pit is selected resulting in waste being mined which uncovers material not of a significant value to deliver a profit; (ii) the long-term price used for the ultimate pit selection is pessimistic, too small of an ultimate pit is selected, and ore of realisable economic value left behind. Both of these outcomes are risks and as such can be assessed and quantified. CITATION: Holloway, E, 2018. Incorporating economic variability into a strategic planning framework, in Proceedings Complex Orebodies Conference 2018, pp 88–90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Zichenko ZA, Volkov SV, Shaluhina LM, Emelyanov AF

A method of selective gold recovery from black sands has been elaborated which is based on the liquid phase low temperature chlorination of materials. A liquid agent mixture of sulphur monochloride S2C12 and sulphur dichloride SC12 is used. This method ensures the gold extraction either in the state of AuC13.SC14 complex salt solution or as metal. The kinetics and main physico-chemical parameters of the process (eg density, solid: liquid ratio, temperature) have been investigated. The materials investigated were quartz-insipid ride samples with low sulphur and high iron (up to 70 per cent Fe2O3) contents. Gold recovery is 96 - 99 per cent at temperatures not exceeding 100¦C. Most of the associated minerals remain in the cake. To obtain metallic gold, the resulting solution of the AuC13.SC14 salt after leaching is reduced by hydrazine with subsequent annealing. The elaborated method is remarkable for small energy expenditures owing to low process temperature and a high gold dissolution rate. The solution of sulphur chlorides and other reagents are used in closed cycle.

Jan 1, 1993

By B Mohanty, D Zwaan

Systematic near-field vibration monitoring of stope blasts was carried out in a large, deep underground mine. A total of 31 production blasts were studied in order to investigate the effectiveness of existing blast designs. This involved the vertical retreat mining method, which requires drilling a raise bore or blasting a slot raise (typically 1.22 m in diameter) using large diameter boreholes (165 mm). The diagnostic technique employed multistation near-field monitoring of blasts with high-g (100 g) and high-frequency (>10 kHz) triaxial accelerometers. The amplitude of the vibrations is correlated with the strain energy transmitted from each explosive deck. The results showed that more than 30 per cent of the explosive decks contributed little energy to the rock breakage process in these blasts, and an equal number contributed only inadequately. These findings are indicative of serious blast malfunctions. The problems can be traced to inadequate deck blast design and possibly to drill hole deviation. The various causes for such malfunctions are discussed and remedial measures suggested.CITATION:Mohanty, B and Zwaan, D, 2015. Assessment of underground production blast designs and blasting performance, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 607–616 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

EIA is a test of a development proposalÆs legitimacy and asks two questions: not only æis the proposal competent?Æ but also ædoes the proposal have moral authority?Æ For reasons of miningÆs historic importance and of a scientific and technological industry culture, traditional EIA has focussed on the first on these, an increasingly misplaced priority in a changing world.This paper explains why competence alone is not enough and examines the second of the two questions: what is meant by a projectÆs moral authority, why does it matter, why has it taken so long to become an issue and what, in practical terms, can project proponents do about it.

Jan 1, 2004

By H Zhang, M Karimi, M Hassan, S Saydam, B Li

With the prevalence of Mine Internet of Things (MIoT), different types of sensors have been widely deployed in mine sites for environmental monitoring and operational management. Currently, sensors in mine sites are mainly powered by cables or batteries. However, the deployment and maintenance of a power supply network can be difficult and expensive, and batteries have a limited lifespan. The vibration energy harvesting (VEH) technology can be used to provide power for lowpower sensors in mine sites. This presentation briefly introduces three widely used VEH methods (ie piezoelectric, electromagnetic, and electrostatic). The performance of a commercial electromagnetic energy harvester (ReVibe model D) is evaluated based on the vibration of a lab vibrator (3 g, 50 Hz) and an idling SUV automobile (0.3 g, 25 Hz). Experimental results indicate that a ReVibe energy harvester can generate adequate electricity to power a sensor, and its power output depends on the load resistance as well as the vibration frequency and amplitude of vibration sources. To apply VEH to mining applications, this study also analyses the characteristics of vibration sources at the mine site based on the vibration data collected from various operating machines in a coal handling and preparation plant (CHPP). The vibration analysis results indicate that all the measured vibration sources in the CHPP can generate stable and abundant vibrations, characterised by substantial amplitudes (up to 5.55 g) and low dominant frequencies (ranging from 14 Hz to 25 Hz), which are sufficient for VEH.

Sep 1, 2024

By J-P Franzidis, M Esvelt, E V. Manla

The Floatability Characterisation Test Rig (FCTR) is a self-contained, highly instrumented, mobile pilot plant that is able to treat up to 2 tph solids. It consists of a bank of six 130 L WEMCO« SmartCells« and a bank of six 50 L WEMCO« SmartCells«. It was developed as part of the AMIRA P9 Project, primarily to determine ore floatability characteristics and to develop and validate flotation plant modelling, scale-up and simulation methodologies. However, it may also be used to carry out pilot-scale flotation test work. This paper briefly describes the circuit modelling, simulation and scale-up test work performed using the FCTR and the use of the FCTR in pilot-plant test work performed by the metallurgical staff at WMCÆs Kambalda Nickel Operations and Mount Keith Nickel Operation. At both Kambalda and Mount Keith the FCTR was found to be very flexible and straightforward to run, with an easily changeable circuit configuration and stable operation. Testwork was facilitated through having full stream sampling on all streams, and a high degree of instrumentation providing accurate measurement of process variables. The results obtained from the FCTR testwork were highly repeatable. As a consequence of using the FCTR, WMCÆs Kambalda Operation and Mt Keith Operation were able to complete a rigorous programme of pilot plant testwork more quickly than in the past, and with a high degree of confidence in the results.

Jan 1, 2003

The introduction of rubber tyred diesel equipment underground in the early 1960's and subsequent design improvements to diesel haulage systems over the past 2 decades has meant that diesel truck haulage has often been the first choice when selecting a haulage system for a new underground mine. Even today only 9% of all vehicles underground are electric powered.However, with the development of more efficient electric haulage systems, the suc-cessful installation of low cost shaft hoisting systems and improvements in conveyor design, alternative haulage systems are appearing as viable alternatives to diesel truck hauling. In particular, the aspects of ergonomic and environmental operating conditions, maintenance and operating costs as well as productivity rates are becoming more and more important in the selection of underground haulage systems. Future develop-ment of existing diesel haulage systems will require that diesel haulage units become more productive, have considerably reduced exhaust emissions compared to existing units and remain the cheapest haulage method for under-ground one way haul distances up to a distance of 3 kilometres. Development of electric truck and associated fuel cell haulage systems

Jan 1, 1985

By S R. Grano, M Vera

This paper deals with two separate case studies investigating the froth phase performance and characterisation of two industrial rougher/ scavenger flotation circuits. Froth phase performance was quantified using a mass balance approach to estimate froth zone recovery. Measured characteristics of the froth phase included frother solution concentration determined by gas chromatography, and the time taken for an equilibrium froth sample to decay to one-half of its original froth height. The latter measurement is referred to as the æfroth half-lifeÆ and is strongly linked to froth stability. Special methods and techniques developed to preserve frother in solution and to measure froth half-life are briefly described. The frother type in the first case study was a mixture of straight and branched alcohols, whilst the frother type in the second case study was a mixture of alcohols, aldehydes and triethoxybutane. The first case study focussed on a flotation circuit treating a low-grade ore containing only a small fraction of floatable copper sulfide minerals, while the second case study focussed on a flotation circuit treating a higher grade complex sulfide ore containing significant quantities of chalcopyrite, galena, sphalerite and pyrite. It was found that froth zone recovery of valuable mineral generally decreased down-the-bank of the two industrial rougher/scavenger circuits. Moreover, decreases in froth zone recovery significantly limit the overall cell recovery of valuable mineral achievable from the plant scavenger cells. However, the decrease in froth zone recovery could not be linked to the removal of frother from the pulp solution to the concentrate product in the preceding rougher flotation stages. Measurements of residual frother in solution suggested that, approximately, only five to ten per cent of the added frother was removed into the rougher/scavenger concentrate, with the remainder appearing in the scavenger tailings. This finding suggested there was apparently adequate frother in solution in the scavenger stages.

Jan 1, 2005

By S Hapugoda

Iron ore oxide and oxyhydroxide minerals such as haematite (eg various types of martite and microplaty haematite), different forms of goethite, magnetite, hydrohaematite and kenomagnetite were analysed using optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) techniques, to determine the type and proportion of deleterious elements present and the chemistry of associated gangue minerals. The aim was to characterise elements potentially deleterious for agglomeration and steelmaking, eg sulfur, phosphorus, aluminium and silicon and correlate their distribution with mineral texture and association, to provide feedback on downstream processing performance and product quality.Examples of characteristic mineral associations are shown from various genetic styles of iron ores, including magnetite banded iron formation (BIF), BIF-derived martite-goethite and skarn-type magnetite ores.A number of examples are presented demonstrating the benefits of the use of combined techniques of reflected optical microscopy, SEM and EPMA data to reliably identify ore and gangue minerals and their associations in different types of iron ores.

Jul 11, 2011

By P M. Cepuritis

In hard rock mining, large-scale bulk mining methods such as block or panel caving (BC/PC) and sublevel caving (SLC) typically generate significant surface deformations such as subsidence. Surface deformations need to be considered in the project evaluation and planning stages of cave mines, for example, planning and location of critical underground mine planning infrastructure such as portals, haulage and vent shafts, access roads, or potential damage to existing infrastructure, changes to surface water management, waste dump, stockpile and tailings dam stability, and environmental impacts. Assessing the impact and risks associated with subsidence is a key component in robust mine planning and operations management.

Nov 29, 2022

By P R. G Milne

A risk-based approach to optimising pit wall slope angles was trialled in the design of a 60m deep open pit in extremely weathered and distinctly weathered materials in the Kalgoorlie area. The pit used for this approach was Stage 1 of a three-stage open pit project. The Stage 3 pit will require long term stability, as it will contain the portal for a long life underground project. Information from failures induced by steeper wall angles used in the Stage 1 pit would be valuable in predicting and preventing long-term stability issues in Stage 3. In this approach, the pit wall slopes are based not on the normal factors of safety, but on the assessment of the probability of failure and the direct and indirect costs of dealing with the failure when it occurs. In this example, the benefits and risks of adopting steeper wall angles were compared in a series of graphs. These charted the increasing probability of failure and simultaneous decreasing factors of safety with increasing pit wall slope, and the range in the possible volumes of circular failures for increasing wall angles. These were brought together in a graph showing the potential excavation savings (in BCM) and the probable cost of a failure (probability of failure times the probable volume of the failure). The resulting pit design was based on the project Mining EngineerÆs semi-quantitative assessment of where and when a higher risk of failure was acceptable and where it was not acceptable as it may have unduly affected the integrity of haul roads or production. The design incorporated wider than normal berm widths to accommodate anticipated failures and to enable modification of the wall configuration if required. Several re-designs were required during the life of the project in response to aggressively induced failures. It is considered that this risk-based approach provides a practical route to optimal pit design and operation but it requires an experienced, dedicated and efficient mining team for it to be implemented with benefit.

Jan 1, 2003

By B A. Webler, P Su, P C. Pistorius

Advanced high-strength steels (AHSS) typically have much higher aluminium concentrations (by an order of magnitude or more) than conventional low-carbon aluminium-killed steels. The resulting lower oxygen activity at the steel-slag interface changes the kinetics and thermodynamics of steelslag reactions. Previous work showed that the rapid transformation of alumina inclusions to spinel inclusions, and spinel to periclase, occurs because of the relatively high concentration of dissolved magnesium. In this paper, experimental results on nitrogen removal by ladle slag are compared with predictions based on the available thermodynamic databases. As in previous work, the kinetics was modelled by assuming mass transfer control, with steel or slag mass transfer limiting. The results show that significant removal of nitrogen by steel-slag reaction is possible.

Aug 21, 2024

By M C. Schodlok

Banded iron-formation (BIF) and iron ores were measured using the CSIRO developed TIRHyLogger ™ to assess its ability to map quartz, carbonates and riebeckite. The TIR-HyLogger™ measures continuously spectral refl ectance data from diamond drill core or drill chips with a high spatial and spectral resolution. Samples from twelve BIF, bedded iron deposits (BID) and channel iron deposits (CID) have been analysed. The spectral data were processed with two different approaches. The first approach, focused on the identifi cation of the major minerals, was performed using principal component analysis (PCA). It identified four minerals (quartz, ankerite, riebeckite and goethite) and provided pure spectra called end-members. The second approach included a mineral diagnostic spectral feature extraction involving wavelength position, relative peak heights and relative depths of absorptions. Quartz has a diagnostic absorption at 8.625 µm and ankerite shows a refl ectance peak at 11.275 µm. In addition to the identified end-members, two carbonate populations (calcite and siderite) and two silica species (quartz and amorphous silica) were identified.

Jul 11, 2011