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By C B. Smith, G L. Boxer, S W. Moss, A L. Jaques, V Lorenz, M J. Rayner

The Ernest Henry Iron Oxide Copper Gold deposit is hosted in a large dilation between two moderately dipping shear zones found in the footwall and hanging wall of the deposit. These shears are controlled by a large diorite intrusion to the north-east and south-west of the deposit, formed ~1660 Ma. A shear zone dubbed the ‘Interlens’ uncovered through underground workings truncates the main orebody into two lenses, and is hypothesized to have formed in conjunction with the Hanging Wall Shear Zone and Footwall Shear Zone. All three shears dip moderately to the SSE (50–140) from open cut exposures through to the current mining horizon approximately 800 m below the surface. Routine geological work and a capital drilling campaign has identified a significant flexure in these sub parallel ore bounding shears with increasing depth. A shift in shear orientation in the Interlens over approximately 100 m vertically from ~50° to the SSE to a steep, easterly trend (~85° to the east) is observed in both drill core and exposures in the underground workings. It is hypothesized the diorite intrusive to the south-west of the deposit controls the shear zone geometries at depth. The geometry of the Interlens mirrors the surface expression of the Proterozoic package of the orebounding shears to the south-west of the deposit, suggesting the surface geometries of the shear zones are consistent with depth. Additional drilling to explore the validity of this hypothesis is planned for the near future to better understand the structural controls on the Ernest Henry mineralisation with increasing depth.

Mar 22, 2022

In recent times there has been a marked increase in public awareness of air pollution. Some of this has been induced by the Press but our own senses tell us that there is a visible haze over our cities on many mornings. The people are now demanding a clean environment and will no longer tolerate smoke and dust fall or gaseous and odorous emission which either soil building and furnishings or interfere with comfort and well being.

Jan 1, 1971

The bureaucracy in Victoria has worked against exploration and mining development. There is no doubt that the new Mineral Resources development Act has simplified matters on the mining side of the system. However, WMC's Bendigo and Deep Lead experiences demonstrate that other parts of the bureaucracy can cause serious delays. The mining industry continues to view the approval process causal of excessive costs and delays compared with other States (and countries) and prohibitive to investment in Victoria.

Jan 1, 1992

By R Thompson, D Tulloch

"Wet-weather or 24×7 wet-trafficability is a commendable design objective for unpaved mine haul roads, but practically often difficult to achieve, due both to the road sheeting material selected, and also its breakdown under the action of traffic and environment. Accidents allied to wet-trafficability issues, either due to rain or often more commonly, over-watering of mine roads, is increasing and especially the loss of control or uncontrolled vehicle movements categorisation. The dominant system failure is that once vehicle control is lost, control cannot be regained.The friction supply, or ‘skid resistance’ of a mine haul road sheeting is critical to the safe operation of the road and data has to be collated concerning the variation of friction supply with sheeting material engineering or indicator properties. In the light of the paucity of data existing in this field, this paper presents the contributory research that informs the development of improved and validated unpaved mine road friction supply estimates, based on a number of mine site evaluations across a range of sheeting material types and characteristic parameters, leading to improved predictive models of friction supply.Results from this preliminary review will enable operators to assess their road sheeting materials, improve and validate unpaved mine road friction supply estimates. This will contribute to improved road design, management and 24×7 operability decisions and contribute to a reduction in heavy vehicle loss of control incidents on gravel-surfaced mine haulage roads.Citation:Thompson, R and Tulloch, D, 2016. What's Stopping You? The Role of Sheeting Material Selection in Safe Haulage Operations, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 253–264 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By A Tawadrous, B Wheeler, D S. Preece, S A. Silling

The two key results of rock blasting are fragmentation and movement of geomaterials. Movement/flow of the blasted rock is often referred to as heave. Moving rock with explosives rather than mechanical equipment can improve mining efficiency. Such is the case with coalmine cast blasting. Controlling and directing rock movement through explosive deck delay timing can greatly improve ore recovery by segregating ore and waste. In both cases, understanding, predicting and controlling heave is an important element of successful blasting.Computer programs for predicting 2D blasting-induced heave have been used in mining for decades, helping to drive the innovation of new and more efficient mining methods, ie cast blasting. The past few years have seen the advent of 3D distinct element modelling of blast-induced heave. This is an important advancement because most blasting situations are three-dimensional in nature, especially when controlling the direction and intensity of rock movement through explosive deck delay timing.This paper documents the first full-scale blasting simulations in 3D with distinct element models that include hundreds of blastholes and in excess of a million particles, made possible with parallel processing. Surface mineral blasting is the focus of this study which treats the effect of blasthole delay timing on ore recovery. Ore waste and dilution resulting from typical row-on-row delay timing will be demonstrated. Also demonstrated will be the ore recovery possible with delay timing designs that significantly enhance ore/waste segregation. This type of high fidelity modelling and the use of electronic detonators makes possible the sculpting of rock blasting muck into separate piles of ore and waste.CITATION:Preece, D S, Tawadrous, A, Silling, S A and Wheeler, B, 2015. Modelling full-scale blast heave with three-dimensional distinct elements and parallel processing, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 127–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By B Oostendorp, R van der Merwe, P

In order to assess whether polysaccharide depressants are strongly or weakly and reversibly bound to the surface of talc, a series of experiments was conducted on New York talc in which the floatability of the talc in a microflotation cell was determined. The talc was conditioned in solutions of carboxymethyl cellulose (CMC) or guar gum in 10-2 ionic strength Ca(NO3)2 or Mg(NO3)2. The talc was then washed with four successive aliquots of water, or cation solution, to try to remove the polymer and the flotation response of the talc was assessed. CMCs of different charge (DS) were used to assess the effect of charge on the strength of bonding. The results show that CMC and guar gum could be removed to a large extent from the talc surface by washing with water (the floatability was restored), however very little could be removed from the surface by washing with cation solution. The higher charge CMC was easier to remove from the talc planes in the absence of cations than the lower charge CMC. Thus CMC bonding to talc has been shown to be irreversible or very slowly reversible only if cations are present, implying that cations are necessary to keep the polymer bound to the surface of the planes to effect depression. The presence of ions in solution also had the effect of maintaining surface coverage of the talc by guar gum.

Jan 1, 2005

By J G Bastias

It is sometimes necessary to resort to extremes in order to call attention to something that is pertinent to safety in mining. When some of the experts in occupational safety talk about this topic, they usually refer to a 'regulation' established by the Romans which stated that, due to the health hazards, usually death, no Romans but only slaves should work in mining. Since the time of the Roman Empire, a lot of ground has been covered in the field of mine safety. Nowadays, it can be said that occupational safety is being seriously addressed, with the result that the number of mining accidents has reduced dramatically, fatalities in this industry are less frequent, and the rate of accidents compared with other activities, such as construction or fanning, is low. This achievement has been possible initially through government legislation and by procedures established by the mining companies themselves. However, the dilemma for government is whether to regulate and if so, how much. It is pleasing to observe that most companies are establishing working procedures which conform with new government legislation, placing strong emphasis on the duty of care for mine employees. There will always be some regulatory aspects of legislation, and perhaps the best example of this is in the use of mine hoists where there are no international or Australian standards, and the regulations applied are of an empirical nature that err on the side of safety.

Jan 1, 1994

By Jensen W. S

The Mount Morgan ore-body is intersected by dykes to such an extent that it presents peculiarly difficult problems in extracting ore. These are shown on Plates Nos. LXVII. and LXVIII. Besides ,these dykes there are innumerable "heads," which alsoare a source of danger. Falls of ore occurred in the end of the year 1908, resulting in serious loss of life to miners employed. It was decided, after an exhaustive inquiry, to change the entire system of mining from the" flat backed stope system" to the" square set sectional system ," the latter being more flexible and allowing bad ground to be cut out from a safe position; but it became evident that, whatever system was adopted, there would be more or less danger unless all the dykesand heads known were picked up, and their continuation plotted on a special set of plans on which the general scheme of stoping could be plotted from time to time as work progressed. It is worth while pointing out that, in every other branch of engineering, it is usual to design the work, and that only in mining engineering has it been common to do the work first and plot it down afterwards.The term "sectional analysis" is familiar in most branches of engineering design, and as applied in this paper to mining, may not bear the same meaning, but the general purpose is analagous, and there is no other term used.

Jan 1, 1911

By Boehme PW, Gregory OR

The results presented here show quite definitely that in the system investigated the intensity of dispersion is enhanced by switching the flow entry from bottom to sides of the packed trough. Since there is no reason to suppose that this would not be true generally then it is not surprising that the blast furnace dispersion data of Standish and Polthier lie above the data for packed columns with bottom fluid entry. In fact, on the basis of the present results, blast furnace dispersion results can never equal standard packed column behaviour but must always be above these. The result that the intensity of dispersion in the trough model is higher closer to the side ports than away from them is at variance with that of Standish and Polthier blast furnace results. Aside from the obvious structural differences between these two systems, it is thought that the presence of raceways and the tortuous path of the gas flow in the furnace may provide an answer. Clearly this is an important difference in the behaviour of the two systems and further investigations designed to clarify the position would have significant practical value. This would also give an indication of how the furnace D/ud values may be decreased along the whole height - assuming of course that this result gives the best overall performance of the furnace. However, there is to date no knowledge whatsoever about this aspect of blast furnace Technology.

Jan 1, 1975

By G Davies, D Dunn, C Mawdesley, O Bertoli

The coal industry in Australia has been actively working in recent years towards the (re)integration of geostatistical techniques to the process of coal resource estimation. The benefits of using geostatistical techniques, over the current interpolation algorithms in use in coal modelling packages used to generate the grid estimates, need to be illustrated for the methodology to gain a broader acceptance in the coal industry. This paper focuses on the benefits gained at BHP Billiton Mitsubishi AllianceÆs Saraji mine for the estimation of the total product yield value at a 9.7 per cent product ash cut-off of a particular seam of the Saraji deposit. In order to perform this comparison, the results of the alternative estimation methodologies need to be benchmarked, which in most situations is achieved through the reconciliation of the estimates against production and/or process plant reconciliation data. Unfortunately, this benchmarking was not possible as no reconciliation data for the area of interest in the chosen seam was available, as it has not been mined at the time of the study. Where no reconciliation data is available, an alternative method is to use conditional simulations as the benchmark for comparison. The simulated values can be regarded as ærealityÆ, and the alternative estimation methodologies, based on a sampling of the underlying ærealityÆ, can then be compared using the simulated ærealityÆ as the benchmark for comparison.

Jan 1, 2009

By McAllister J

Oxygen was in restricted use at Port Kembla until tonnage oxygen became available for steelmaking in the open hearth furnaces. In adopting the new process various modifications to furnace design and operation were necessary and some of these, including increase in roof height and variation in firing and draft control, are discussed.The design of oxygen lances is also discussed and various steelmakingtechniques considered.Steel production increased with oxygen roof lancing-one- furnace producing 8,507 tons in one week-but new problems, such as rate of refractory wear, and disposal of fumes, were created.Design of future open hearth oxygen furnaces is predicted.INTRODUCTIONIn the post-war era, the availability of "tonnage" oxygen caused a major revolution in steelmaking techniques. Various pneumatic processes showed that steel can be madeat a very fast rate and that oxygen steelmaking can be applied to open hearth furnaces. Methods used are surface impingement with roof lances, bath injection with door lances, flame enrichment with fuel firing, mixed gas and oxygen firing, and enrichment of normal combustion air by oxygen injection into the flue systems.Owing to its previous restricted availability and high cost, oxygen was used in rather small quantities in the open hearth furnaces at Australian Iron and Steel Pty. Ltd.(A.I. & S.), Port Kembla, until about the middle of 1960.At that time tonnage oxygen became available and roof lancing commenced on No. 33 furnace at No. 2' open hearth shop.

Jan 1, 1962

By Hargraves A. J

At 4 MPa gas pres ure and 30°C the sorptive capacity of 10 selected Australian dried coal ranges from 17 to 23 m3/tonne of CH4 and 27 to 36 m3/tonne of CO2. Values for moist coals are about 25 per cent less. At 20°C, sorptive capacities are about 18 per cent greater. No clear relationship between coal rank and sorptive capacity was established.The permeability of coal to gas is dramatically reduced by progressive hydrostatic confinement. No single 'permeability' for a coal can be established because of relative affinities of coals and the gases (Ar, CH4 and CO2) used in experiments. Bedding plane permeability is significantly greater than permeability normal to bedding. Dependent on gas/coal combinations, permeabilities without confinement ranged from 150 to 0.05 millidarcies, and with 8 MPa hydrostatic confinement from 1.0 to 0.001 md. Generally, permeability is increased by reduction in temperature, and reduced by increase in moisture as one changes from Ar through CH4 to CO2. In retrospect, it is preferable to ubject permeability sample to 8 MPa hydrostatic stress only once, because changes occur in the samples and it is difficult to use other gases successively.The initial rate of desorption, DP, does not appear to be a reliable index of proneness to instantaneou outbursts for Australian coals.The methods used for determining quantitative gas-coal properties appear suitable and reliable for testing other coals.

Jan 1, 1985

By Sewell L. G, White H. S

OWING to two large falls of ground which resulted in serious accidents occurring towards the end of 1908, it became evident that the "open chamber" system then in use was unsuitable for the conditions existing in the Mount Morgan mine. It will be admitted that in all mining operations the first consideration is the economy of the system adopted, combined with its safety and ability to give the desired output. A sectional system with square sets has been introduced into the mine, in which due attention has been paid to these factors. In this paper a brief description of this system will be given. An outline of those previously used will be included, as it is necessary to understand the conditions which existed in the mine at the initiation of the sectional system. Outside the actual mining methods employed, various points that might prove of interest will be touched on.The square set system of mining has been in use throughout, the stopes in the gold ore in the upper levels of the mine since underground operations were started in Mount Morgan. In the oxidized zone the ore was of a friable nature, and in some cases rImning ground was encountered. In the lower levels the ground became heavier, and although the stopes were for the most part long, wide, high, and irregular, and not sectionalized, no difficulty was experienced in winning the ore, and no accident of a serious...

Jan 1, 1911

By T Raynlyn, R J. Holmes, J R. Manuel, A Poliakov, L Lu

The prediction of sintering performance of iron ore fines and the possibility of targeted optimisation of specific sinter properties are very important for both the iron ore industry and related research organisations. Physical pilot-scale sinter runs require large amounts of raw materials and are expensive, so it is critical to target large test work programs with many different sintering parameters effectively. To predict values for sintering performance parameters such as tumble index (TI), low temperature reduction disintegration index (RDI) and productivity, a comprehensive database of pilot-scale sintering experimental results has been established and empirical modeling conducted. Similarly to earlier work, physical, chemical and mineralogical characteristics of the iron ores have been considered. However, in contrast to the previous work where only one textural parameter was taken into account, namely the proportion of dense haematite ore texture, the current model includes the abundances of several different textures which were combined into different textural factors corresponding to different sinter properties. Coefficients for the variables within specific regression equations can provide a better understanding of the effect of the variables on the corresponding sintering performance. The modelling results have also been used for predicting the sintering performance of mixtures that were not part of the database used for establishing the models. Comparison of experimental and modeling results for the verification test data is also reported in this paper.

Jan 1, 2009

By J D. Lubben

Hibbing Taconite is a Lake Superior-type granular magnetite taconite deposit occurring within the Biwabik Iron Formation along Minnesota’s central Mesabi Iron Range. The deposit is situated on the northern margin of the Proterozoic Animikie Basin. The deposit strikes northeast, dips gently southeast, and occupies 10 km of strike length. Mining focuses on 50 m of granular cherty and laminated slaty taconite within the Lower Cherty member.Ores generally consist of a quartz, magnetite, siderite, ankerite, minnesotaite, stilpnomelane, and haematite mineral assemblage. Processing is optimised by exploiting the physical and chemical variations that exist between three major ore types. Taconite ore averages 20 per cent magnetic iron (MagFe), 27 per cent weight recovery (WtRec) and produces a final concentrate with 4.5 per cent silica (SiO2). Since 1976, production has totalled approximately 237 million long tons (Mlt) of pellets (8 Mlt per year rated capacity).Ore processing uses a simple fl ow sheet of autogenous grinding (<0.044 mm) followed by two phases of wet magnetic separation, fi ltering, limestone/bentonite addition, balling, and firing to create pellets averaging 66 per cent total iron. A Liberation Index (LIS) is used as a primary guide for ore grading and metallurgical control. Grind requirements, magnetite liberation and silica grade are closely monitored to ensure plant optimisation and product quality.A recent program of benefi ciation of low-grade ores by in-pit crushing and dry magnetic cobbing has demonstrated that low-grade ores (<17 per cent MagFe, <25 per cent WtRec) can achieve a signifi cant metallurgical upgrade (up to 25 per cent MagFe and 40 per cent WtRec). This operation recovers 60 per cent of the total crushed volume, and has a calculated effi ciency factor (magnetic iron recovery) of 79 per cent. This paper discusses the benefi ts of this upgrading and its effects on ore blending and processing.

Jul 11, 2011

The valuation of resources companies is open to a huge amount of subjectivity. Not only are valuations subject to fast changing assumptions, such as commodity prices, exchange rates, ore grades, etc., but there is also no common agreement on the methodology to be used. To borrow from Malcolm Fraser, life wasn't meant to be easy for the resource company valuer. I will demonstrate three recent examples of valuations carried out but where the market or actual transactions done show very different results.

Jan 1, 1989

By Crawford J

The paper asks the question 'Why Limit the HYDROTRANSPORT of material to the confines of your washplant'.A brief historical review of widely accepted slurry transport operation establishes that we are not talking about new technology - simply applying proven experience to an innovative continuous system.The paper reviews a simple potential application and compares capital and operating costs with conventional trucking.No attempt has been made to develop a complete mine plan and the comparison has been limited to material transport costs.

Jan 1, 1992

By Till M, McGee WA

The Hermit Islands are situated at 145¦ E 1 30'S in the Bismarck Sea approximately 200km WNW of Manus Island. They are dominated by basalt flows, one of which yielded a K/Ar isotopic date of 3.4 + 0.05Ma. All basalts examined were olivine-bearing, but one sample also contained hornblende. Although many outcrops were weathered, no evidence of pervasive hydrothermal alteration was observed on any islands and non-weathered rocks are petrographically fresh and many retain glass.

Jan 1, 1990

By J Masliyah, Z Xu

The largest oil sand deposit in the world is located in Alberta, Canada, with a total proven reserve of 2.5 trillion barrels of oil. The water based extraction process is currently being used in commercial operations to recover bitumen by flotation from oil sand ores. A recognised challenge in bitumen extraction is the reduced bitumen recovery when processing ores containing high fines content or æweatheredÆ oil sand ores, collectively known as poor processing ores. Inspired by demonstrated success of using kerosene as collectors in coal flotation, an innovative idea of using oily bubbles (air bubbles coated with a thin layer of oil or solvent) was tested to improve bitumen flotation recovery from poor processing ores. In this study, dynamic contact angle of air bubbles or oily bubbles on bitumen and induction time of bitumen-oily bubble attachment in water were measured to justify the use of oily bubbles in bitumen recovery from poor processing ores. The type of oil or solvents, including kerosene, toluene and naphtha, used in generating oily bubbles showed a marginal effect on the contact angle values, similar to the values measured with air bubbles. However, the spreading of an air bubble was found to be much slower than that of oily bubbles on a bitumen surface. The induction time for oily bubble-bitumen attachment was found to be much shorter than that for corresponding air bubble-bitumen attachment in the process water from poor processing ores. The reduced induction time for kerosene-coated air bubble-bitumen attachment correlates well with the improved bitumen recovery from poor processing ores using kerosene-coated oily bubble flotation technology.

Jan 1, 2005

When a major mineral find has been announced the general perception is that a battle between Aborigines and the mining company involved will inevitably occur.It is a fact that many miners in the past have not had a good relationship with Aborigines because of their indifferent attitudes towards them. They saw no common future and went their particular way. However, attitudes have changed significantly since Noonkanbah and both miners and Aborigines are seeking common ground in order to achieve mutual benefits from the establishment of a mine on or near Aboriginal land. There are many obstacles that both miners and Aborigines need to overcome inordertofindthiscommongroundtoachieveawin/win situation. The obstacles can be found in entrenched ideas and practices which need overhauling, not the least of which emanate from government policy and requirements.Without going into specifics, the Noonkanbah incident during the 1970's where Aborigines and their supporters confronted miners who were ordered by the Western Australian governmentto drill on Aboriginal land, polarized Aborigines and miners. Since this incident, many Aborigines, particularly those in the cities, have had the attitude that mining and Aboriginal culture are in direct conflict. Aboriginal opinion is generally shaped in the larger cities through mass media coverage of the opinions of urban Aborigines and their supporters. Through no fault of their own, these Aborigines were removedfromthe land of their ancestors and have notlived atraditional Aboriginal life-style for a number of generations and most have little knowledge of, nor have had involvement in, traditional Aboriginal lore and culture. For the most part these people live in awestern life-style and few still know their language. They generally have high profiles, often giving viewpoints that are wrongly considered "Aboriginal" and supposedly representing all Aborigines. This group is very different with their thought processes and values from those Aborigines who live on their own traditional lands with a traditional life-style, and practise their age old ceremonies. Their tribal values are based in their relationship with the land, expressed through complex religious ceremonial rites of song, dance and legend. Today this group is very much diminished in numbers but nevertheless in the region of the Gulf of Carpentaria there is a high proportion ofpeople who practise their lore, speak their own languages and pass on traditions to their children. It is well documented in the history of Australia that Aborigines have been decimated in numbers and whole tribes have been wiped out. Certainly in this region the experience has been no different.

Jan 1, 1993