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SINCE writing the above-mentioned paper, some further indicator cards have been taken from the No. 1 machine, and the writers believe that a reproduction of these cards will be interesting as illustrating the performance of the machine after fifteen month steady running, night and day, seven days per week and twenty-four hours per day, at the average speed of fifty-seven revolutions per minute (see Fig. 1, page 60). For the past twelve months no adjustment have been made in the valve setting, and the only repairs have been in connection with the springs of the poppet valves, and these but slight, the springs latterly having been removed. The cards illustrated were taken with one indicator, and, therefore, are not simultaneous, andmay show to some extent the yariations of individual strokes, and with that qualification may be taken as typical of the machine's average performance.In connection with some feed-water measurements of the winding engines a rough test was run with the two compressors, the Riedler and the Corliss, coupled to the condenser, and running at fifteen and fifty-seven revolutions per minute respectively, with the result of 15.9 pounds of steam per indicated horse power per hour. This result, though only approximate, seems to indicate that the No. 1 machine is running under the guaranteed consumption, and that it is capable of maintaining this under the severe conditions of everyday practice.

Jan 1, 1909

The resistance of lead to chemical attack and the ease of its fabrication has made it one of the most useful of the metals available to the chemical engineer and the electrometallurgist. It has proved to be of particular value in the manufacture of sulphuric acid, and since the conversion of the sulphur of pyritic ores into sulphuric acid is becoming the duty of the metallurgist, the corrosion resistance of this metal will be a matter of considerable interest to him from the standpoints of both producer and user. He realises that there is little to be gained in carrying the process of purification past the ordinary economic limit if little or nothing is to be added to its corrosion resistance, and he as user would not be willing to pay a premium for such purification if it can be shown that its reputed value has no scientific foundation.The metallurgist is well acquainted with the trouble and expense of meeting demands which have nothing torecommend them but prejudice and fancy. The valuable anti-corrosive properties of lead are very commonly ascribed to its forming insoluble compounds with the acids sulphuric, hydrochloric, carbonic, etc. If we trusted superficial visual evidence alone, such a view would receive strong support, but in the light of what we know of the mechanism of corrosion we must attribute its resistance to other factors much less obvious to casual inspection. Certainly there may be some mechanical obstruction set up to diffusion of the liquids towards the surface of the metal.

Jan 1, 1932

Scientific drilling and blasting techniques are currently being presented to the mining industry as an aid in the overall optimisation process. The degree of success in the development of these techniques over the last ten years has prompted statements that generally relate to blasting becoming a science rather than an art. Many of the techniques are currently operated or at least analysed by scientists. As such, their use has been restricted to project type activities while the more routine activities associated with day to day mining has continued to be carried out by engineering rather than scientific staff. Some of the scientific techniques will remain legitimately as a project or an occasional use facility. Generally speaking a cost/benefit analysis at a particular mine will decide the level of use. This should logically highlight a number of techniques with potential of regular mine site use. Regular mine site use implies mine site analysis and hence the gulf between the scientist and mine operator/engineer must be addressed. There are all sorts of solutions and they are not mutually exclusive. One alternative could be to increase specialisation at the mines. With "career paths" becoming more formalised the trend would seem to be away from mine site specialists unless, for instance, this specialisation was provided by term secondment from research establishments. Another alternative could be the scientists themselves applying their developmental skills to "humanise" and "package" the projects in such a manner that they can be routinely used at mines.

Jan 1, 1990

By B Leyland

The media in Australia is currently rife with articles and pronouncements on global warming as the most significant crisis of our time, which may æthreaten the future of civilisation as we know itÆ. This has been recently reinforced by release of Al GoreÆs film æAn Inconvenient TruthÆ, and one would be led to believe that the science of global warming is settled. And yet there is a strong body of literature disputing this apparent consensus which suggests that care should be exercised in introducing radical policies to solve a crisis which may not be real. Such policies would have a major impact on those in professions such as engineering (project approvals and design to minimise greenhouse gas emissions), accounting (carbon tax issues) and the law (corporate disputes on greenhouse gas issues are already in train in the USA). This paper addresses the hysteria apparent in the climate change debate by presenting factual evidence relating to climate change and the current phase of mild global warming. Some of the more extreme statements on future impacts are repudiated with published data, and alternatives to the purported role of fossil fuels in temperature change are offered. The potential impact of political decisions on professional activity is discussed, as are the implications of a possible future reversal of the scientific consensus, as has occurred in the past. The paper concludes with a call for the professions to exercise their Learned Society role to ensure that a rational and public debate is held on the broad issue of climate change.

Jan 1, 2007

I start with some lines from "Pleasures of Hope" by the poet Campbell, published in 1798, which sets the flavour of what I am going to say. They blissful omens bid my spirit see The boundless fields of rapture yet to be; I watch the wheels of Nature's mazy plan, And learn the future by the past of man. I hope to echo the poet's optimistic view of what is yet to come. I am not sure I can find all the omens blissful but we all have some experience of what the wheels of Nature's mazy plan get up to. His advice to learn the future by the past of man seemed sensible to follow, so on the principle that the past of several men would be better than one alone I invited Alan Attwood, Maurice Cahalan, Gavin Moncrieff, Derek Temple, and Peter Wright to help me prepare this address; I am most grateful to them for their contributions. Of the technologies covered in this sequence of keynote addresses, metallurgy is the one which is closest to our consumers. On the age-old principle, which I do not expect to see changed in the 21st Century, that production is about providing the customer with what he wants, when he wants it, where he wants it, and at a price he can afford, I think we should start by trying to see how the market place is likely to develop, and to work back from there to review what technology we need to meet these demands.

Jan 1, 1986

By C Hall, P Hazell, C Wilson

Every mine is situated within a water catchment – a catchment with potentially many other land uses. A mine may take up a relatively small area in that catchment, but its operations have the potential to affect the whole catchment and long after that mine has ceased to operate. Therefore, the residents of any given catchment have the right to feel secure in the knowledge that their catchment, and indeed the wider environment, will not be degraded by mining activities. Much conflict can arise when this confidence does not exist.But, imagine if a community not only felt confident that their catchment would not be degraded by mining activities, but was also confident that their catchment would be left in a better and continuously improving condition – with improving water quality, biodiversity and soil - and a strengthening, more resilient economy. CITATION:Hazell, P, Wilson, C and Hall, C, 2018. Landscape regeneration lessons learned from Mulloon Creek, in Proceedings Life-of-Mine 2018, pp 125–126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

Author Biography William Poole was born in Sydney, NSW in August 1868. He was educated at Sydney Grammar School. William spent two and a half years as a cadet in the Railway Construction Branch of the NSW Department of Public Works doing office and field work. He then undertook a civil engineering course at Sydney University. Following this he was employed for six years as assistant and resident engineer at the Water Conservation Branch, NSW and was in responsible charge of various field operations, surveys, river gaugings and works of constructions including a large timber weir and also a concrete weir on the Macquarie River, NSW. He then undertook a mining and metallurgical course at Sydney University and became a graduate (BE) with honours in civil engineering, mining engineering and metallurgy. He then spent four and a half years with BHP Co, one and a half years at Broken Hill in the mining and concentration works and three years at the smelting works in Port Pirie, SA, in the latter case he was metallurgist and night superintendent and during that time had responsibility and control at night of the blast furnaces and, during the last 15 months, of the whole of these large works. The author left the Port Pirie, SA works to assume the position of Director of the State School of Mines at Charters Towers and had responsible control of the establishment and also lectured in mining, surveying and structure. William Poole was honoured to hold membership in the following organisations: Assoc M Inst C E, L S of NSW, M Aus Inst M M, Assoc Inst M & M (London).

Jan 1, 2006

Citigold Corporation operates the Warrior gold mine at Charters Towers, northern Queensland, mining narrow quartz veins (0.1 to 2 m wide) in granodiorite by long hole open stoping on levels 15 m apart. Access is by decline and cross-cuts with on-ore development drives. The mineralisation comprises Palaeozoic mesothermal quartz veins containing gold, pyrite, sphalerite and galena, hosted by the Ordovician age Towers Hill Granite. The gold grain size is variable from 1 to 500 ¦m with 1 m face samples up to 800 ppm Au, and average run-of-mine grades of 10 to 14 ppm. Despite the spectacular gold tenor, little visible gold is present. Gold grades are highly variable presenting challenges in ore reserve estimation. Tonnages are discounted by 70 per cent to allow for the low payabilities (30 to 50 per cent) of the veins. Estimation techniques allow high confidence in overall global grade estimates but poor reliability on a local scale (25 m). Kriging ranges as low as 5 - 8 m means that obtaining a Proved Ore Reserve by diamond drilling is not economically feasible, and broad-scale mine planning decisions are made at the Inferred Mineral Resource stage and mine design work at the Probable Ore Reserve stage. Proved Ore Reserves can only be estimated after underground development has proceeded through the mineralised body with levels at 15 m vertical spacing sampled at 2 - 3 m intervals along the level. However, reconciliations between actual gold produced and earlier resource estimates produce workable results. A further three mines are scheduled to be developed underneath the city of Charters Towers.

Jan 1, 2008

As an Inspector of Mines in Queensland, my main responsibilities include the enforcement of the Mining Act 1968 - 1986, the Mines Regulation Act 1964 - 1983 and the Metalliferous Mining regulations 1985 to promote the safe and responsible exploitation of the States' mineral wealth. An important adjunct to this task is the offering of an advisory service to the mining industry. However, in the pursuit of my duties to this regard, I have sadly observed in some cases, numerous wrong doings and negative activities by miners which have led to their ultimate demise, not to mention that of others. Despite what I consider corrective advice, I have witnessed, again in some cases, disregard and blind pursuit for the wrong end. This then is a novel approach to get the message home in the form of a light hearted cartoon presentation relating the saga of an average Aussie battler entering the mining game unprepared, making the wrong decisions due to his own ignorance and the cleverness of others, leading finally to his and possibly others' downfall. It is not intended to insult any particular profession or group of individuals and only endeavours to impart to readers and listeners, the message of being prepared and alert when entering the gold mining industry. Even though the presentation focuses on the woes of a rookie alluvial gold miner, a similar analogy could be drawn with his hard rock counterpart since the basic issues that I have attempted to address are common. By no means is there a saga complete because there are many more traps a miner can inadvertently fall into and only time has prevented me from referencing them.

Jan 1, 1989

By S Grano, M Fordham, H Manouchehri, J Curral

This paper focuses on the impact of high pulp temperature on sphalerite flotation after the zinc regrind circuit in the Zinc Plant of Somincor, owned and operated by Lundin Mining Corporation. In the zinc circuit, the zinc rougher concentrate is reground with forged steel media before flotation with one stage of roughing and scavenging, and three stages of cleaning to obtain a zinc final concentrate (zinc grade >50 per cent). After regrinding, sphalerite flotation has been found to be seriously affected by high pulp temperature which may occur during the summer months. Mineral recoveries were found to be seriously reduced at pulp temperatures above 60¦C. At this high pulp temperature, neither elevated copper sulfate concentration nor a decreased pH alone appreciably increased Zn recovery. However, a combination of these two (eg a decrease in pH from 11.5 to 10.8, and an increase in copper sulfate dosage from 400 g/t to 800 g/t) was found to reduce Zn depression at high pulp temperature. At pulp temperatures below 45¦C, the negative influence of pulp temperature on mineral recoveries was minimal. A systematic series of flotation tests and solution/surface analyses were performed to reveal causes for poor sphalerite flotation at high pulp temperature after regrinding. The decrease in mineral recovery was shown to be associated with variations in the surface species on mineral particles in response to the increased pulp temperature. These variations in the surface species include collector desorption and superficial oxidation to form lead/zinc oxide/hydroxides on mineral particles. The influence of the type of regrinding media on sphalerite flotation at high pulp temperature was also addressed in this work.

Jan 1, 2008

The Osborne copper-gold deposit (within the Trough Tank project area) is located in the Cloncurry Shire about 195 kilometres south-east of Mount Isa. It is hosted by Proterozoic metasediments of the Eastern succession of the Mount Isa Inlier. The deposit is overlain by 25-40 metres of Mesozoic cover, so it represents a true "blind target". Placer Exploration has 100% outright ownership of the property, having purchased the remaining 10% interest in the property from Shell in early 1993.Intensive exploration, both surface and via drilling at Osborne, has taken place since 1985, when CSR Limited Mineral Exploration and Development Group (acquired by Placer in 1988) entered into a joint venture with Billiton Minerals. Exploration effort from 1985 to June 1988 outlined a 20 kilometre strike length of magnetic horizons, in what was termed the North-East, Central and Southern anomalies, which were drilled with weak indications of copper-gold mineralization in the North-East anomaly. During the later half of 1989, four core holes were drilled into the shallower northern partofthe North-East anomalywhere previous drilling had outlined economic intersections of mineralization. These holes encountered high-grade copper-gold mineralization confirming the potential for an economic deposit to be hosted within the ironstone sequence. Further drilling involving over 400 holes (100 kilometres of drilling) has brought the deposit up to its present resource status.The current resource inventory is 36 million tonnes grading 2.0% copper and 1.0 grams pertonne gold and includes a high-grade zone of 13 million tonnes grading 3.6% copper and 1.5 grams per tonne gold. The discovery of this potential economic mineralization resulted from a persistent exploration effort based on indications that a large mineralizing system existed within a sequence of ironstones.

Jan 1, 1993

Completion of a project requires two separate money-focused activities, namely economic evaluation of the cash flows underlying the project (before financing) and if the economics look promising, how it can be financed. Economic evaluation might be best led by a person with a technical-operating background, whereas financing might be best led by an accountant. Both should be presented in simple language with easy to understand models. Economic evaluation has a sad and bad history because it evolved from the fringes of accounting. Anyone can become a self-appointed practitioner. Some still take pride in mathematical complexity without realising that they distance themselves from the decision-makers and alienate other team members. Today there is no evaluation modelling consistency across the mining industry and this reflects poorly on our discipline. It is not tolerated amongst our peers in engineering and accounting. In 2009 æbest practiceÆ economic evaluation modelling is well defined. It is:easy to follow;tailored to its purpose;transparent;discipline, rigour and consistency;recording of all source data; and hencequick to audit. Mantra: If you cannot readily understand my model you do not have a problem, I do! The task of the economic model is to make the range of business cases underlying the decision easy to understand. Intellectual power is used to simplify the decision to its key issues and risks and to present the full range of possible business outcomes in readily understood terms. Project team members, management and the board must be able to make their decisions with æeyes wide openÆ. A steering committee should be established to develop a set of standards and practices that could be adopted for economic modelling within the industry. The industry needs to purge itself of the undisciplined economic evaluation modelling that now characterises the discipline.

Jan 1, 2009

Mispah form (FAO: Lithosol) soil contaminated with >380 000 mg kg-1 creosote was co-composted with sewage sludge and poultry manure for a period of 19 months. The soil was mixed in a ratio of 1:1 (v/v) with wood chips to improve aeration. The soil-wood chips mixture was then mixed in a ratio of four soil-wood chips mixture: one compost material (sewage sludge or poultry manure). Compost heaps were set up in triplicate on wood palettes overlaid with double layers of nylon straw bags. Control experiments, which contained the contaminated soil-wood chips mixture without sewage sludge or poultry manure were set up in triplicate. Moisture, temperature, pH, ash content, C:N ratio of the compost and the creosote concentration of the soil was monitored monthly. The concentration of selected creosote components in the soil was also determined at the end of the incubation period. Temperature was observed to rise to about 60¦C in the poultry manure and about 58¦C in the sewage sludge within two months of incubation, while temperature in the control fluctuated between 15¦C and 35¦C throughout the incubation period. Creosote concentration in the control was reduced by 17 per cent at the end of the incubation period while concentration of creosote in the sewage sludge and poultry manure compost was reduced by about 99 per cent. The percentage rate of creosote reduction in the poultry manure compost was initially lower than observed in the sewage sludge compost. However, the reduction rate became similar towards the end of the treatment period. The concentrations of selected creosote components were reduced by about 100 per cent within the same period. Respiration of compost microorganisms and counts of microbial populations showed that microbial activity correlated with reduction in creosote concentration.

Jan 1, 2004

Basicity(aO2−) has been known to affect the physicochemical properties of molten slags in the metallurgical processes. However, because of the impossibility of direct measurement of single-ion activity, various indirect measures such as capacity, redox equilibrium of transition metal ions, activity of basic oxides, and (theoretical) optical basicity have been proposed; but these basicity measures have been restricted within slag systems and the interaction between measuring elements and slag components has affected the quantitative estimation of slag basicity. Recently, since it was reported that solubility of noble metals in molten slags could be an indirect measure of basicity, the influence of slag basicity on the solubility of platinum and silver has been reported. The reaction mechanism of platinum dissolution into basic slags has been reported, whilst that in acidic slags has not (Nakamura and Sano, 1997; Sano and Nakamura, 1997; Nakamura et al, 1998). Richardson reported that the solubility of metals such as cupper, gold, silver, and lead in the CaO-SiO2-Al2O3 slag was presumably dependent on the atomic radius and the accommodation ability of the silicate network (Richardson, 1974). Swinbourne and You measured silver solubility in the Na2O-SiO2 slag over a wide range of oxygen partial pressure and suggested that silver would be present as both Ago and Ag0.5 in the slags (Swinbourne and You, 1999). For brevity, these previous works discussed the dissolution mechanism of silver into the slags based on the existence of silver as a neutral or molecular species. However, because the almost chemical reactions occurring in the slag are affected by the basicity, the reaction formula with O2- ion is required based on the ionic characteristics of the slag such as desulphurisation and dephosphorisation reactions as given in Equations 1 and 2, respectively.

Jan 1, 2000

By I Ametov, G Levay

It is now common practice to use substantial amounts of recycled water in mineral processing plants to minimise both environmental discharge and withdrawal of fresh water from often limited water resources. Recycled water additions to process water are frequently obtained from sources such as tailings dams, tailings thickeners and concentrate dewatering. It has been suggested for some time that addition of recycled water to process water will impact the quality of the process water and that changes in water quality may influence flotation performance. To date, investigations of process water quality changes as a result of water recycling have been limited and as a consequence there are very few data available to substantiate these ideas. Thus the impact of recycling on process water quality remains largely unquantified. Over recent years we have conducted water quality studies at a number of mineral flotation plants with varying degrees of water recycle. This paper describes the results of these investigations, including data which suggest that build up of salinity due to recycling while it occurs, is reduced by fresh water make-up. The fate of flotation reagents such as collectors, promoters, frothers and flocculants during process water recycling has also been investigated. Results show that process water concentrations of these reagents vary from plant to plant, but that, with the exception of frothers, most reagents are generally removed from the system through mineral adsorption. In general, the results of these investigations suggest that recycling process water will not result in continuous increase in solute concentrations as appears to be the commonly held view.The effects of changing water quality on flotation can vary. In many cases, flotation conditions can be optimised to suit the water quality, while in others, treatment of the water may be necessary to obtain acceptable plant performance.

Jan 1, 2009

By W J. Bruckard

In Australia, ilmenite is produced from beach sand deposits. These deposits contain varying quantities of the valuable minerals zircon, rutile and ilmenite, along with a variety of other minerals. The valuable minerals are upgraded using combinations of gravity, magnetic and electrostatic processing techniques to yield high-grade products. One of the penalty elements present in ilmenite concentrates is chromium, present mostly as chrome spinels. This mineral is particularly difficult to separate from ilmenite, as the properties of the two minerals are very similar in relation to the traditional separation processes. While the deposits which have been treated in Australia in the past have had only low levels of chromium present, many of the newer deposits contain much higher levels of contamination and, thus, there is an increasing need to develop robust processes to separate chrome spinel from the ilmenite. Flotation, which is a unit process with the potential to solve this problem, has surprisingly received little attention for this application. The literature suggests the research effort to characterise the general flotation properties of chromite (chrome spinel with high chromium content) has been extensive and a substantial amount of data is available. However, the problem of separating a small amount of chrome spinel from a large amount of ilmenite requires a different approach to that from separating chromite from siliceous gangue, which has been the main commercial focus of chromite flotation in the past. Much of the work done has been fundamental in nature and the results obtained are fairly inconsistent, as is the testwork completed at batch and pilot plant scale. While these inconsistencies have been attributed to the variable composition of the mineral, there is little evidence supporting this premise. Just as chrome spinel and ilmenite have similar physical characteristics, the flotation response of both minerals is also similar. This paper reviews the literature relating to the flotation of chrome spinel and presents a considered approach to the development of a robust flotation method to separate chrome spinel from ilmenite.

Jan 1, 2001

By J Stojanovic, V Kasic

Gold-bearing polymetallic sulfide deposits are common in Serbia, and mostly occur in the Karpato-Balkan and, to a lesser extent, the Serbo-Macedonian metallogenic province. These deposits û Coka Marin (Majdanpek), Grabova Reka (Blagojev Kamen), Lece (Medvedja) and Veliki Cip (Boranja) û are dominated by Cu and/or Pb-Zn mineralisation that contains a variety of Pb, Zn, Cu and Fe (¦ Sb, As, Bi) sulfides and sulfosalts, as well as native elements. Gangue minerals are composed of quartz, carbonates and rare silicates and barite. Based on their gold content these deposits can be divided in three groups:1. Polymetallic deposits with a high gold content (>1 g/t).2. Polymetallic deposits with an intermediate gold content (0.1 to 1 g/t), and3. Polymetallic deposits with a low gold content (<0.1 g/t). Gold occurs as native gold or as an alloy with silver. Native gold ranges in size from 5 to 20 ¦m, with a few rare grains over 100 ¦m, as isolated grains or as microveins (in the first group of deposits). Its distribution within the deposit in uneven. Native gold in the second group is smaller in size (1 - 5 ¦m, rarely 20 ¦m), where it is uniformly distributed in a quartz-silicate matrix. The third group is of no economical importance. The subject of research has been the first group of polymetallic deposits.

Jan 1, 2008

By Just J, Nguyen G, Dunn J. G, Graham J

A sample of pyritic gold concentrate was investigated by wet chemical and electron optical techniques. Sub-samples were roasted in a laboratory scale fluidized bed roaster in the temperature range 400-700¦C. The calcine was characterised, and cyanide-leached using a standard bottle rolling test. Gold extraction efficiencies varied with roasting temperature. At temperatures of 400 and 450¦C gold ex- tractions of less than 40% were achieved, but between 500-700¦C the extraction had increased to 93--98Z. The surface area of the calcine varied with roasting temperature, reaching a maximum at 500¦C. There was no correlation between the surface area of the calcine and the efficiency of gold extraction.

Jan 1, 1987

By Hodkinson I, Slight M

Over the last five years Mt Leyshon has matured into a sizeable gold mine by Australian Standards. In the later part of 1990, after commissioning of the 3.5 mtpa CIP Plant upgrade, experience indicated there was potentially additional Mill capacity beyond that being utilised at the 3.5 mtpa rate. Overall throughput was limited by crushing plant performance and high operating costs resulting from the age and condition of the main crushing plant.In addition, mining was being carried out using a mining contractor who utilised relatively small, high cost mining equipment, and on-going exploration success was also indicating that the then current mine plan would result in only a portion of the available resource being exploited.

Jan 1, 1992

Rehabilitation has been very effective in the short to medium term in providing a cost effective and reliable means of containing the side effects of land disturbance. However, there is still insufficient data to critically evaluate the sucess of rehabilitation in the long term. There is an urgent need to develop objective criteria to monitor the sucess of rehabilitation. The aim of rehabilitation in Australia has traditionally been to return disturbed land to natural vegetation compatible with the surrounding area. This objective has often been accepted instinctively without adequately addressing alternatives.

Jan 1, 1992