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Prospecting in arid terrain can produce substantial environmental impacts, comparable to or greater in magnitude than the impacts associated with actual mining or petroleum production. Impacts are likely to be particularly severe where prospecting involves intensive geophysical exploration, especially in areas which have escaped degradation by other land uses such as pastoralism. With appropriate environmental planning and management, however, the environmental impacts of prospecting in arid terrain can be greatly reduced and mitigated, at low cost. In many countries, prospecting licences, exploration leases and associated tenements now carry a range of conditions relating to environmental protection. The assessment, avoidance and mitigation of environmental impacts is therefore an important component of and-zone exploration. My aim here is to give an overview of some of the main aspects of an environmental planning and management (EPM) programme for prospecting in arid terrain (PAT). Detailed operational prescriptions for environmental protection procedures are necessarily specific to particular areas and types of prospecting: see. e.g., Buckley (1982a, 1984, 1985a, 1986a), Klepacki et al. (1985) and Stone (1986). The intention here is to provide a checklist rather than a recipe book: as an aid in incorporating environmental aspects into the overall planning and management of an exploration programme, and in liaison with company environmental staff, consultants and regulatory bodies. I also hope to show that whilst some of the techniques used in particular environmental disciplines certainly require specialist expertise, the overall design of an EPM programme is not in the least esoteric, but simply an exercise in straightforward common sense. Perhaps this paper could be subtitled: "Demystifying environmental Planning".

Jan 1, 1988

By D Liang, L Zhang, X He

The sulfurisation-flotation process was unsuccessful when initially applied to the oxidised Pb-Zn ore in Lanping County of Yunnan Province China. A comprehensive mineralogical study indicates that the problem is caused by the soluble salt gypsum in the Lanping oxidised ore, which produces a large amount of Ca2+ cations. The Ca2+ cations react with S2- anions (from sodium sulfide) in preference to Zn2+ and Pb2+ forming calcium sulfide, and make it difficult to form zinc and lead sulfides on the surfaces of the respective oxidised Zn and Pb minerals. In addition, the calcium sulfide formation consumes a large quantity of the available sodium sulfide, further inhibiting the sulfurisation process. The efficiency of the sulfurisation of oxidised Zn and Pb minerals has been improved greatly by the pretreatment removal of gypsum, with the added benefit of the required dosage of sodium sulfide being substantially reduced.

Jan 1, 2008

By Y Gu, W McCallum

Mathematically sophisticated methods are now in common use for metal balancing of complex separation flow sheets at many concentrators. These balances usually entail minimisation of the sum of weighted squares of data adjustments subject to flow sheet constraints. The adjusted data provides numerical consistency across the complete flow sheet to facilitate performance calculations. A mine with multiple ore sources can be considered as a flow sheet with the end node comprising the concentrator and its products concentrate(s) and tailings. If the mass transfer and grade estimates for each ore source are sufficiently reliable, a similar metal balancing approach can be used for combined mine and concentrator data. Comparison of balanced and measured assays and mass movements provides useful guidance to security of marginal grade ore and possible dilution problems. This paper includes a summary of results from a case study based on a mine with multiple ore sources.

Jan 1, 2002

As the oxide reserves in an oxide/sulphide deposit are exhausted transition to the treatment of sulphides should be investigated in detail and well before processing the sulphide ore commences. The investigation should be broad based to consider all treatment options and not restricted entirely by the existing process plant treatment method. These options may include cyanidation, flotation, roasting, bacterial leaching or gravity treatment and are chosen on the basis of various testwork responses. Experiences in laboratory testing of sulphides and treatment of sulphides at various operations are discussed. This includes the treatment of copper/gold sulphides, CIP treatment of sulphides and treatment of marcasite ore in a conventional CIP circuit.

Jan 1, 1989

By Wu H. W, Just G. D

Australia's mineral resources boom in the two decades up to 1980 saw the establishment of about 25 new mining towns across the continent Quality housing and a high standard of community services were incorporated to attract a labour force for the major mine or mines i eing serviced. Town construction costs were high and were principally born by the private enterprise mine developer. There has been a change in the pattern in recent years and over 20 new mine developers have adopted a fly-in fly-out arrangement rather than construct new towns. Employees are drawn from a home base which is typically a large city, coastal community or established mining town and flown to the mine site for intensive work periods of about two weeks. The change has occurred for many reasons. Mining companies have been unwilling to support the high construction costs of towns, short life and smallermining operations do not justify a town, fast jet aircraft are available and there is a better perceived family lifestyle in established (coastal) communities. On the other hand reduced permanent development at new mine sites does not assist Australia's perceived need for decentralization. There have been questions as to the social problems which may develop from the artificial separation of the "breadwinner" from his family. The paper reviews a recent survey of the attitude of Australian mining companies employees, governments and unions to fly-in fly-out arrange- ments. The support for this approach is analysed and conclusions drawn that the concept is likely to be with the Australian mining industry for some time in the future.

Jan 1, 1991

By Willis G. M

Preliminary experiments have shown that, when used in a fusedchloride electrolyte, titanium carbide anodes dissolve yielding lower titanium chlorides which nlay be electrolysed in situ to produce a cathode deposit of pure titanium metal. The anode residues are easily withdrawn from the cell. Further experiments have established the operating conditions for maximum efficiency in the process.The process is essentially two-stage, viz.: (1) titanium carbide production, (2) electrolysis producing metal. Power requirements appear to be moderate and this fact, combine·d with the simplicity of the process make it attractive as a possible method for the production of titanium.INTRODUCTIONDue to the high reactivity of titanium and its, affinity for oxygen and nitrogen, the extraction of this metal generally involves the use of halide. compounds as intermediates. For instance, magnesium reduction of titanium tetrachloride is the basis of the well established Kroll process and electrolysis of the lower chlorides in a molten salt bath has been proposed by Cordner and Worner (1951, p. 358) and others (Brenner and Senderoff, 1952, 223C; The TitaI Company (Inc.), 1952) as means of production of the metal. Thedifficulty of preparation of these compounds prompted a search for an alternative extraction process. The fact that aluminium, an equally reactive metal, has been prepared by electrolysis using aluminium alloy anodes suggested the possibility of a similar process for titanium production.The Titan Company (Inc.) (1952) has patented the use of crude titanium metal anode, but it was thought possible that a metallic compound, such as the carbide, could be used for this purpose. Although Lorenz and Kaufler (1909) suggested the use of carbide anodes for metal production, no...

Jan 1, 1956

Much has been written about leadership over the years. It is probably one of the most written about but least understood and defined concepts in business. Leadership and management are often confused and blurred, and inspirational words such as mentor, coach, motivator and the like, are often interspersed when describing a leader. There are a few things we do know about leadership:The only thing common to all leaders is that they are different.Leadership is not the sole domain of business; it applies to every aspect of human endeavour. We are all required to lead at times, and we all have it in our ability to lead. There is no set of predetermined competencies, which a leader must possess to be effective. Hence there is no course in the world that can teach you to become a leader. There is no such thing as the perfect leader. Leadership is a verb, not a title; you actually have to do it to be judged a leader. All leaders no matter how you define the term, must leave a legacy. Thus in the busy world we all live in, what are the lessons in leadership that we can all learn from, that will assist us all in our pursuit of leadership. The purpose of today is to put forward a framework for leadership that I have been researching and working on for many years. It is not the definitive framework, merely a framework. Out of today you will take your own collective thoughts, learnings, observations, experiences, education and training, and collective wisdom, and apply it to yourself.

Jan 1, 2004

Environmental leaching methods such as the toxicity characteristic leaching procedure (TCLP) test or the ASLP test are used to assess wastes including mining and mineral processing by-products. These tests were initially designed as regulatory tests simulating conditions in a co-disposal municipal landfill waste facility and do not allow leaching performance to be predicted in site specific scenarios. Further, the assumptions underlying these tests tend to define worst-case scenario leaching conditions for by-products from the mineral industry disposed of outside a co-disposal scenario.   Recently some characterisation leaching test methods have been issued as ISO/TS standards (ISO/TS 21268-3:2007 and ISO/TS 21268-4:2007) that aim to define the leaching performance of soil type wastes and to predict the leaching performance of these wastes over long time frames. In this preliminary work these standards are trialled for by-products from the mineral industry and the quality of information that can be obtained from them compared to TCLP/ASLP tests.   Where clear comparisons were possible, the TCLP/ASLP tests were typically found to extract a similar, or often greater, amount of component than (i) tests conducted at the same pH but without the acetate buffer or (ii) for test conditions aimed at simulating long-term leaching in an eluate defined by the waste type. While further work is required, the preliminary results indicated that the tests may provide reliable long-term estimates of leaching performance of wastes in soil types of variable pH and provide a suitable basis for long-term planning for optimal waste handling, treatment or even re-use.

Jun 1, 2010

By B McFadyen, Y Potvin, K Woodward

The Australian Centre for Geomechanics (ACG) held two workshops in 2019—one in Australia and one in Canada—to discuss processes and methods currently used in the mining industry for stope design and reconciliation. In practice, this work strives to optimise stope performance and aims to maximise ore recovery (minimise underbreak), while minimising dilution (overbreak). One of the key findings from the workshops was that current stope design practices, almost exclusively, rely on some versions of the empirical Stability Graph methods developed in 1980s. Although robust and useful at the feasibility study stage, there are a number of inherent shortcomings with this approach. The Stability Graph’s limitations first lie in that it cannot assess underbreak, which is a very important measure of performance. Furthermore, the method doesn’t consider a number of factors which often have a critical influence on stope stability, for example, drilling and blasting or the presence of faults. Given the current industry standard practice, there is a great opportunity to reinvent the stope design process to optimise performance. A finding of the workshops was that every mine quantifies stope performance in terms of volume reconciliation with a focus on dilution and ore losses, and reconciling metal tonnes recovered from the mill. Many mines further investigate stope performance by looking at individual stope faces and the causes for the deviations between the planned stope shape and the measured cavity. Recent research at the ACG has shown that investigating overbreak and underbreak at a higher resolution is a powerful way to identify the root causes of overbreak and underbreak. Finer scale assessment is achieved using an octree analyses, which effectively divides the relevant stope volume into cubes on the scale of a metre and produces many tens of thousands of data points. The octree data structure and subsequent analysis underpins a data-driven stope design methodology. The ACG is currently developing a design approach based on multivariate modelling methods that can account for the many variables that influence stope performance and forecast stope overbreak and underbreak results. Back-analysing stopes based on octree reconciliation results provides a rich database for training the model. Once the model can achieve reliable forecasting of overbreak and underbreak, an interactive drill-and-blast design will allow for the assessment of different firing strategies to optimise stope performance.

Mar 15, 2021

By Tukkimies M

During the late-1980s crawler-mounted crusher units established their position in the aggregates industry. Between 1986 and 1994 about 700 units were delivered to customers all over the world for surface operations, mainly in Scandinavia and central Europe. The crawler-mounted units are popular among smaller crushing operators because they are versatile and easy to move between sites. In large quarries the greatest benefit is obtained by combining a primary crawler-mounted crusher unit with mobile belt conveyors which eliminates the need for costly haulage by dump truck. Savings of up to 40 per cent in production costs prior to secondary crushing have been achieved. Today the environmental aspect in quarrying is assuming ever greater importance. Besides being costly the dump trucks are also the major source of dust and exhaust fumes within a quarry. A complete face crushing system consisting of a crawler-mounted crusher unit and mobile belt conveyors can be electrically driven and can be equipped with dust encapsulation and dust collectors. A mobile crushing unit is not a new idea. From the mid-1950s onwards the mobile and self-propelled units have been built equipped with crawlers, tyres or walking mechanisms, with weights usually of 500-1000 t. Due to their massive size these unit are not mobile in the same way as the today's mobile units. It is not feasible to move them more than a few times a year unlike today's fully mobile units which are often relocated once an hour. This means that the massive units can not continuously follow the production face and their loading always requires a certain amount of haulage. Today the mining industry is facing new challenges. With low mineral prices and high labour costs, increasing productivity is essential for survival. New standards are also being set for the labour safety and the environment. Large research programs have been launched to meet these challenges. However, technology which can partly solve these problems already exist and is only waiting to be introduced into underground applications as well - the mobile crushing unit followed by belt conveying. As in surface operations the elimination of truck haulage also brings considerable savings in operating costs in underground mines and reduces the amount of dust and exhaust gases generated. An additional benefit especially in underground applications is improved safety. In an underground mine most accidents are caused by moving vehicles.

Jan 1, 1995

By S Shipard

Filters are used in water treatment and hydrometallurgical process plants for objectives such as generating a dry spadable solid, pumpable high density slurry or high purity filtrate. The priority objective of every polishing filter, sometimes also termed clarifying filters is high purity filtrate and these are found in many diverse industries and even different applications within the same industry.To generate a high purity filtrate, process designers have the choice of many different polishing filter products, but in reality very few polishing filters are based on fundamentally different filtering concepts.This paper reviews the technology merits of well-known and the more recently developed polishing filter products and aims to assist metallurgists and engineers with the selection of an appropriate polishing filtration technology for pregnant liquor filtration and other process applications, plus a guide to best practice.CITATION:Shipard, S, 2013. Polishing filters for mineral processing plants, in Proceedings MetPlant 2013 , pp 118-125 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By S N SHEARD

The use of geophysics in mineral exploration in Australia, and overseas, has increased dramatically over this century. This paper shows that using simple equipment with clever interpretation that the foundations of modem geophysics were laid, using all the same principles. The plethora and diversity of mineral exploration geophysical techniques does not allow a full description of their evolution to be given in such a paper. To convey this evolution, however, the progress of two different geophysical methods, magnetics - a potential field (passive) method, and electromagnetics - an electrical (active) method, are described. Examples of magnetic survey data from the 1920s and more recent vehicle home and airborne surveys are given to show the increase in data quality through technological improvement. A set of four airborne electromagnetic data sets spanning three decades is used to indicate the improvement in electromagnetic techniques. It is argued, that considerable progress is still required in the electromagnetic field to increase its interpretability.

Jan 1, 1992

By Mercer JK

This paper gives a description of the research undertaken by an explosives manufacturer to give better technical advice to the Mineral Industry. Blasting Physics is defined as giving a systematic and coherent account of the initiation and subsequent effects of high explosives upon the surrounding medium. As a result of this work a mathematical model based on the gener- ally accepted mechanism of blasting has been developed. The mechanism and the resulting model are briefly outlined. IFrom'this model the effects of burden, spacing, blasthole diameter, rock and explosive properties upon fragmentation and heave can be calculated. Using these calculations it is then possible to see how variations in frag Imentation and heave can affect the overall production costs of a mine whether it is surface or underground. The overall costs are made up of a number of individual costs - drilling, blasting, loading, hauling and crushing. ach of these operations influences or is influenced by fragmentation and heave s these costs are inter-related, the

Jan 1, 1975

Mining is taking place at increasing depths of cover on the Southern Coalfield beneath pre- dominantly massive sandstone strata. Within the next twenty years, there will be longwall mining at depths greater than 600 m. As the Sydney Metropolitan area continues to expand and as coal mining approaches these urban areas subsidence will continue to become an increas- ingly important aspect of coal mining research. Investigations commenced in the mid 1960's and it is now possible to predict subsidence in the Southern Coalfield with reasonable con- fidence. The work is showing that the characteristics of the subsidence troughs over the deeper mining at Appin differ from the characteristics of mine subsidence at less cover. The longwall mining at Appin Colliery has resulted in a maximum measured subsidence of 730 mm. The maximum strains were small because of the large radii of curvature of the subsidence profiles. There was no damage to any of the buildings in the township of Appin.

Jan 1, 1981

The Prince Lyell Mine has been the major production source at Mount Lyell since under-ground mining commenced in 1972.Three lifts of stopes have been mined to date, with the fourth, the 40 Series lift, to commence production this year. As the mine has progressed deeper, the ore haulage system has evolved to accommodate the mine's economic circumstances while maximizing efficiency.In the first, or 10 Series lift of stopes, ore was removed from drawpoints by L.H.D. units and tipped directly into rakes of 7 tonne rail cars. The original concept for deeper stoping lifts entailed L.H.D.'s tipping into long ore passes, rail haulage, underground crushing and hoisting to surface via the No. 1 Shaft. The suspension of the No. 1 Shaft project in 1976, due to economic difficulties, lead to the intro-duction of diesel truck haulage of ore, initially via the internal Prince Lyell Decline and now to surface via the Main Decline.

Jan 1, 1985

By Frith RT, M D. Goodz

Drilling has been accepted as a major exploration tool. However its use in mine planning and development has been overlooked.This need for drillhole data was highlighted during the redevelopment boom of the central Victorian gold mines. During the 1980's numerous old mines were evaluated and successfully drilled to yield mineable parcels of quartz reefs close to existing workings.Invariably the initial decision was always to attempt reopening and rehabilitating existing access. The four case studies described have proceededsufficiently to show that major cost savings would have been made if underground drilling had been used as the main tool in mine planning.Savings not only in expenditure, but in the time required to make key decisions. In two cases the mines would have experienced far earlier expansions in production. In one case the mine would be currently producing rather than awaiting further finance. In the fourth example, the decision to case development would have been much earlier providing capital to other projects.

Jan 1, 1990

By Miyatani J. Asaki Z, Kondo Y

The oxidation of sphalerite particles of 60 to 100 mesh size was studied in a fluidized bed of low 02 concentration at 900¦C. Par- tial pressure of 02 in the fluidizing 02-N2 gas mixture was chosen between 0.0009 and 0.02 atm. In the region of p02 between 0.008 and 0.02 atm, the oxidation rate was lowered with the decrease of p02, and the unreacted-core model was applied. At lower pbelow 0.008 atm, the reaction rate was enhanced as compared with the calcu- lated values from the unreacted-core model. From microscopic examination, it was found that ZnS was evaporated at the particle surface and the dissociated Zn vapor was oxidized in the gas phase. Initial reaction rate and the distance between the surface of inner sphaler- ite core and the oxide shell were studied based on the model of enhanced oxidation.

Jan 1, 1980

By M D. Rosengren, G Gregor, M F. Young

Over the last 15 years the silver/lead/zinc ore treated at Mount Isa became increasingly complex and lower grade. Metal recoveries dropped dramatically, causing a serious decline in profitability. The ætraditionalÆ response of increasing tonnage to reduce unit cost was unsuccessful, since the additional tonnage was even lower quality ore. A major technical and capital program in the 1990s restored metallurgical performance, but business return was still too low and ore quality continued to decline. In 1996 a new, holistic approach integrated the steps of geology, mining, concentrating, smelting, and refining. Previous assumptions about æfixedÆ and æmarginalÆ costs in mining and processing were shown to be wrong. Detailed analysis showed that some ore sources were reducing profit. This led to a fundamental redesign and downsizing of both Mount Isa and Hilton mines. The result was dramatic increases in head grades, metallurgical performance and plant stability without any capital expenditure. The business is now smaller, but more profitable.

Jan 1, 1998

The Honeymoon Well nickel sulphide deposits are located in the Agnew-Wiluna greenstone belt, about 45 km south of Wiluna. Both disseminated and massive sulphide nickel deposits are hosted by komatiitic rocks within the deformed and metamorphosed Honeymoon Well ultramafic complex. Fresh ultramafic bedrock is covered by up to 50 m of highly conductive transported material which greatly hampers both exploration and understanding of the bedrock geology. In the early-1970s, mineralisation was discovered by diamond drilling geochemical anomalies defined by wide-spaced percussion drilling over ultramafics that had been outlined by ground magnetics. Subsequent drilling has defined a resource of 158 Mt at 0.71 per cent nickel (based on 0.4 per cent nickel cut-off, 300 m below surface, December 1995) in four deposits. Over the life of the project a wide range of geophysical techniques have been used including airborne and ground magnetics, time domain clectromagnetics (EM), induced polarisation (IP)/resistivity, gravity and downhole techniques including EM, IP and physical property Measurements.

Jan 1, 1996

By Noller B. N, Mine F. J

Modem open cut and underground mining in the tropics inevitably expose partially weathered and unweathered rocks to oxygen and water, leading to weathering and the release of solutes and often acidity as well. Historical monitoring data can demonstrate these phenomena. Three case studies from open cut mines in the north of the Northern Territory illustrate the deterioration in quality of pond water receiving drainage from waste rock dumps. The potential for deterioration of water quality was not recognised in many mine Environmental Impact Statements prepared and accepted in the 1980s. The examples documented indicate the importance of adequately planning for this near inevitable process. Retrofitting a mine water management system to 'no' or minimal release can be very difficult and expensive, and may not be feasible, leading to downstream pollution. The characterisation of acid and solute production potential of ore and waste rock, and improved dumping strategies and water management are very important to minimise the environmental impact of mining in the tropics.

Jan 1, 1994