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By G Harbort, C Sola

The rapid development of geometallurgy in the mining industry has occurred in relatively recent times. Its importance as an independent discipline in the mineral processing world has been emphasised and recognised. To a large degree, this is the result of a growing understanding of the ore type being processed and their application to provide better metallurgical responses in different mineral processing techniques. The development has matured from early progress through to geological knowledge and into the realm of the metallurgist and mining engineer. Working together, they have developed a powerful framework that will interpret a body of mineralisation into measurable properties.The integration of geometallurgy and operations has become of increasingly important due to improvement in understanding of an orebody as a natural system formed by a number of processes and with a definite fabric of mineralisation within different geological domain. These have to be taken into account when creating techniques that will enable operations to extract the valuable components from a distinct type of ore. Incorporation of such knowledge at an early stage of development, such as the feasibility stage significantly reduces the project risk.This paper is written from the unique perspective of a process engineer embedded within a geological team. It discusses issues such cross discipline communications and misconceptions and details the numerous tricks, traps and treasures of geometallurgy encountered during defining of the Seminco and Taysan resources.CITATION:Sola, C and Harbort, G, 2012. Geometallurgy - Tricks, traps and treasures, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 187-196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Cunningham CG

Many epithermal gold-silver deposits areknown to occur in the Neogene-Quaternary volcanic complex of the central Andean region of southern Peru, northern Chile, western Bolivia, and north-western Argentina, an area of about 300,000 km2 where these volcanic rocks constitute the dominant cover. Some of the gold-silver deposits were mined during Spanish colonial times, as early as the 16th century,- whereas others were not discovered until the 19th and 20th centuries. The extraordinary gold-silver potential of this young volcanic complex, however, was not recognized until the 1970's when the phenomenal increase in gold and silver prices stimulated new exploration. New discoveries were made, chiefly in southern Peru and northern Chile, of high-grade ores in old mining districts and large low-grade ore bodies, both in old districts and in new areas having no history of mining activity. Many additional gold and silver deposits remain to be discovered within and beneath the young volcanic complex of this region.

Jan 1, 1990

By J Tuma

Technical measurements are an integral part of research and development of new technical devices. Now they are also an integral part of production too, especially as a part of quality control systems. More new problems started with they applications up, like storing and following preservation of big data files. Many problems are also with processing of the measurement results, especially to be up to standards of ISO 9000 normative. It includes basic data about the measurement (structured data) and measurement outputs (huge data streams). Using database systems looks as good idea, because of structured measurement data and they processing. They were developed more concepts of database measurement system support during the research project MSM 272300012. It was decided to develop specialised measurement systems, on the base of experiments and experiences with they use in operating conditions. It proved to be wrong to develop general system, because of compound operating and long response of the system. And it is not possible to use these systems for mass production systems. The problem of data storing is not as easy to be answered, because of dependence on used technical devices. During realisation the measurement system for gearbox noise measurement are data stored to the database, because used analyser system PULSE (Brnel and Kjµr Co) is open structure and can cooperate with other software systems. Anyhow the data streams are not longer (after compression) than the Memo data type, in practical use increases the data file too fast (about hundreds MB daily). Therefore we must include a special supervisory system for administration and creating data files to the system. Nevertheless the used system MS-Access supports data files up to 1 GB, for practical application is better if the file size do not exceed the capacity of CD-ROM disc.

Jan 1, 2003

We often read and hear, especially in the United States, that we are running out of critical metals. These are vague forebodings of stagna- tion or winding down of our civilization. Our technological progress has been rapid in the last 50 years and is still advancing at an accelerated rate, and predictions of its long-term impact on consumption and production of metals are more hazardous than ever in the light of the great economic and political shifts that are bound to continue. There are many factors that will have a hardly predictable but profound effect on pro- duction and consumption of metals over a time span of, say, 25 years. Among such factors are recycling, substitution, availability of capital, direct involvement of governments in financing and production, and the capability of producing much lower grade ores at possibly much higher prices relative to costs in the event of scarcity. I must state at the outset that my discussion of this topic does not take into account the role that deep-sea nodules containing copper, nickel, cobalt, and manganese may play, because I don't believe production from these deposits will be of much significance within the 25 year span I will be discussing.

Jan 1, 1978

By A Richmond

"In some lode-style gold deposits the geological (lithological) uncertainty may have similar economic significance as the grade uncertainty. In the absence of precise knowledge of the deposit geology, geological models of these types of deposits that are used to constrain spatially the estimated (or simulated) grade values may influence significantly the contained metal. Methods for assessing geological uncertainty quantitatively are rarely considered due to their perceived inability to consider exhaustive geological interpretations, and resulting models that often appear geologically unrealistic. Furthermore, should the lodes have been subjected to folding, or where the mineralisation continuity does not follow a planar orientation along strike or down dip, standard methods of variography and interpolation using linear vectors in space often do not provide a good representation of continuity. An alternative approach is to relate spatial samples from adjacent drill holes using an unfolding plane.The paper demonstrates conditional simulation of the geometry and gold grades of a folded lode-style deposit where:simulation of lode geometry considers explicitly the geologistÆs interpretation, andsimulation of gold grade values that consider explicitly the folded nature of the lodes.The results are contrasted to the traditional approach of linear vectors in real space for a single lode interpretation.CITATION:Richmond, A, 2012. Conditional simulation of a folded lode-style gold deposit, in Proceedings Narrow Vein Mining 2012 , pp 149-154 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

By Bluck R. G

The Murray Basin is known to contain major deposits of heavy mineral sands and intensive exploration for new deposits is being conducted in Victoria, South Australia and New South Wales. The western Basin was well served in the Pliocene and Early Pleistocene by a variety of appropriate sediment sources, and potential coastal traps. Immature, fluvially-sourced sediments forming the Pliocene coastal complex of the Marmon-Jabuk Range in South Australia are part of a marginal marine assemblage containing a suite of economically important heavy minerals that include ihnenite, zircon, rutile and tourmaline. From a consideration of Pliocene palaeogeography and coastal dynamics, specific targets where concentrating processes are likely to have operated are identified in the South Australian portion of the Murray Basin. Such palaeo-environments include the down-drift, littoral zone of discrete foredunes or coastal barriers, the source area for transgressive dune complexes, tombolo facies, and intertidal shoals and sandbanks. Similar coastal processes are recognised for a preserved Early Pleistocene barrier complex.

Jan 1, 1990

The process of refurbishment is not a precisely defined one. It is under- stood to mean an upgrading of a plant which is normally performed only once. The application of refurbishment in the field of materials hand- ling equipment poses particular problems because complex plants con- sist of individual components having quite different remaining service lives. For this reason, a systematic, proven procedure is proposed for the refurbishment of large materials handling equipment, designed to ensure economic implementation in accordance with the company goals. Rheinbraun2 has been using materials handling equipment since 1900, the largest units today being bucket-wheel excavators with a daily capacity of 240,000 bank cubic metres of overburden and a service weight of up to 13,500 t (metric tons). Since 1975, more than 50 large-scale refurbish- ment projects have been carried out in the company. In the process, refur- bishment has turned out to be the proven alternative to replacement of large materials handling equipment. Rheinbraun Engineering,3 a Rhein- braun subsidiary, carries out planning, consulting, and supervising work in the implementation of refurbishment projects in Germany and abroad. The most recent example is the refurbishment of Dredger 11 of the State Electricity Commission of Victoria in cooperation with Krupp-Australia, Melbourne.

Jan 1, 1989

Australia had an active uranium mining industry in the 1950s with uranium oxide being supplied under contract to the atomic energy authorities of the U.K. and U.S.A. In the 1960s, when these con- tracts concluded, domestic production ceased, apart from Rum Jungle, whose production until 1971 was stockpiled. By the 1970s, the demand for uranium from the electrical utility industry had risen sharply and the effects on Australia were notable. The Mary Kath- leen mine re-opened in 1976 but, more significantly, exploration activity suddenly expanded with the re- sult that several world-standard deposits were locat- ed. Western world requirements for uranium based on increasing energy consumption and a changing energy mix, will warrant the development of Aust- ralia's resources. By 1985 our mines could be pro- ducing 9,500 tonnes of uranium oxide yearly and by 1995 the export value from uranium could reach that from wool. In terms of benefit to the community the economic rewards are considerable but, in terms of providing energy to the world, Australia's uranium is vital.

Jan 1, 1978

By Yushan Ma, Jiqing Wang, Hanyi Jia

The Hedong Gold Mine is located in the Yantai area, Shandong province, China. It is an underground mine with an annual gold output of some 700 000 grams. The orebody is located on the edge of the Wanger Shan metamorphism zone, and the hangingwall of orebodies is thus defined by a prominent set of fractures. The proximity of the metamorphism zone and the inclusion of the fracture set ensure that both the orebody and the country rocks are unstable. The main orebodies dip at an angle of between 40 to 45¦, with a strike length of 160 metres and a horizontal width of 50 metres. Surface subsidence in the area is not permitted. Cut and fill mining is usually practiced. As the mining operation proceeds to greater depths, the ore grade is diminishing and it is necessary to find a more efficient stoping method. Sublevel open stoping with sequential extraction and filling of each sublevel has been designed and applied in situ. This new mining method is called æsublevel open and fill stoping methodÆ in the mine. Experience to-date is that new mining method is satisfactory.

Jan 1, 1998

Large scale open pit mining at Ok Tedi and Misima are described in this paper. The paper also presents the socio-political problems encountered in the construction, operation and waste disposal of high technology, high output gold and copper mines in very remote and rugged terrains. Despite these handicaps, mining companies from all over the world have established top class mining facilities including huge open pits, underground mines and mineral processing plants to extract rich mineral deposits of gold, silver and copper.Papua New Guinea is the sixth largest gold and copper producer in the world. New projects likely to come on stream before the end of this century would make it the world's third largest gold producer. The mining industry is the largest organised industry in the country employing over 10 000 persons and investing over US $1000 million on these mega projects per year.

Jan 1, 1992

The importance of the minerals industry to Australia is briefly reviewed and the professional specialists essential for the industry identified. The average first degree graduation numbers in geoscience, mining engineering, metallurgy/materials and chemical engineering are shown and compared with the postgraduate numbers. Demographic trends in population are reviewed and the implications for the required numbers of trained specialists indicated. Short/medium and long-term possible solutions to potential shortages of trained personnel are canvassed.

Jan 1, 1997

By Davison GR

The cost of drilling consumables is always a large component of any mine budget. It is important that this cost be carefully examined with a view to reducing the overall cost per inetre or at least minimising its escalation.At Renison it is considered that the only way to ensure drilling costs do not rise unduly is through a total system of control from purchase to disposal.In 1979 extension of an existing drill supply service contract was carefully examined and abandoned in favour of a hybrid system. This system is providing a great deal of control over the use of drilling consumables and has maintained a relatively constant cost per drilled metre over the last five years.Current consignment stock contracts for drilling consumables are strictly specified by the Technical Services section of the Mine Department and consumables purchased under these contracts are distributed and refurbished/sharpened by a contractor.The total result of this package is individual drilling items that achieve the best cost per metre and careful distribution and maintenance to ensure maximum life.

Jan 1, 1985

Zinc concentrates from the newer mines and from proposed developments provide both opportunities and processing challenges to the conventional roast-leach electrowin smelters. These concentrates are often characterised by low iron, elevated silica, possibly high manganese, and levels of elements such as germanium which may cause concern. In addition, environmental constraints on residue disposal are forcing significant changes to some smelter practices. Iron in concentrate, and the resulting environmental impact of residue disposal are now major questions. However, normal concentrate tariff structure provides a disincentive against smelters taking high grade concentrate and oxide fume. Processing technology to cope with these changes is reviewed, as is de-watering and materials handling of ultra-fine concentrate. Within a few years, such fine concentrates will account for up to 1 000 000 t/y of contained zinc. New processing technologies including novel transport methods, siliceous leach circuits, manganese removal cells and front-end smelting will become significant in zinc smelting.

Jan 1, 1993

By Turner T. M, Jorgensen F. R A

The tendency of the concentrate to ignite was studied using four techniques, namely, laminar flow furnace, fluid bed, thermal analysis and boat-in-furnace. Exothermic activity occurred at two temperatures: minor activity in the vicinity of 200¦C, major activity at 330-350¦C. The low temperature reaction was due to the ignition of a small amount of free sulphur while the major activity was associated with the ignition of the sulphide minerals, notably pyrite. To avoid ignition of the sulphide minerals, the gas temperature should not exceed 300¦C and the oxygen content of the gas phase should be as low as possible. It was shown that little of the arsenic in the concentrate entered the gas phase during drying.

Jan 1, 1987

By Jeffrey IC

This paper presents a method of measuring field power consumption of shearers and deriving specific energy consumption versus shearer haulage speed performance curves. A description of a computer program which simulates the cutting action of a shearer drum is presented. A comparison between the field specific energy curves and the computer simulation results is made. The simulation results compare well with the field data where all the coal seam is being cut by the shearer. The computer simulation results give back-calculated field pick force cutting characteristics, which allow the performance of the shearer to be predicted for other operating conditions, e.g. effect of changes to pick lacing, effect of changing the drum rotational speed, allows the calculation of power requirements for a particular production rate.

Jan 1, 1992

Major exploration companies can have a problem with what to do with small precious metal ore bodies located through exploration programmes. Low tonnage, but high grade, ore bodies too small to justify in-house development.1.2 Ban Ban Mining is a Sunshine Coast based partnership with considerable expertise in mining and earthmoving which specializes in the mining of small/medium size ore bodies on behalf of the tenement holder on a profit sharing or royalty basis.1.3 The partnership's first successful venture has been the mining and vat leaching of a small 40,000 tonne ore body with a head grade of 5 gm/tonne gold and 32 gms/tonne silver, situated near Ban Ban Springs in southeast Queensland.1.4 This paper looks at the low cost vat leaching method of treatment, as an alternative to CIP and CIL in the processing of low tonnage/high grade precious metal ore bodies.

Jan 1, 1990

The first stage in the refining of lead blast furnace bullion is the removal of copper and this is normally done as a batch process in open kettles,A number of attempts have been made in the past to establish fontinuous processes operating in reverberatory type furnaces, but the growth of accretions in the furnace has always presented a serious problem.This has been overcome in the plant of the Broken Hill Associated Smelters Pty Ltd at Port Pirie by the construction of a reverberatory furnace and ancillary cooling system of novel design.Although a number of mechanical and metallurgical problems still remain to be solved, it is claimed that a workable continuous copper drossing process has been established.

Jan 1, 1963

Pilot plant work has played a major role in the process development and design phase of the Iscor Heavy Minerals project. The pilot plant campaigns have been aimed at three process areas, namely primary beneficiation (wet gravity circuits), heavy mineral separation and ilmenite smelting. A process development structure was put in place, and the various pilot plants designed and built. A number of pilot campaigns were conducted during the project phase since 1995, and most of the key objectives were achieved. Various other valuable ælessonsÆ were learnt, and were incorporated in the full-scale plant designs, or used to change operating philosophies, equipment choices et cetera. The cost and durations of the pilot runs were significant, and an analysis indicated that the major risk and technology area of smelting has contributed more than 70 per cent of the total cost.

Jan 1, 2001

Neutralisation, normally using lime, is the most widely used method for treating high flows of acid mine drainage (AMD). Lime costs can be very high however. If carbonate sources could be used to achieve pH values above six, costs could be greatly reduced. For example, use of locally quarried limestone at Mt Lyell could potentially reduce alkali costs from about $A 3.5 to $A 1 million/year. Methods for enhancing the effectiveness of limestone and magnesite for neutralising Mt Lyell and Savage River AMD respectively have been examined through a series of investigations. Small-scale testwork found that the maximum pH economically achievable with ground limestone was about five, due to slow dissolution rates and surface armouring. The problems of surface armouring were greatly reduced by the use of crushed limestone or magnesite at high pulp densities (75 per cent solids w/w), enabling pH values >6 to be achieved in a practical time frame. The use of particle sizes in the range 6 mm and finer also reduces costs by avoiding the need for grinding, and reduces the problems of solid-liquid separation and solid recycling that arise if large additions of ground carbonate are used. Pilot scale tests were carried out using tumbling drum reactors with limestone and Mt Lyell AMD and a pulsed-bed static reactor with magnesite and Savage River AMD. pH values averaging 6.2 and 6.4 were achieved with Mt Lyell and Savage River AMD respectively. Approximately 80 per cent of feed acidity was neutralised. A preliminary engineering design and cost estimate has been completed on the pulsed-bed reactor and shows that the concept is technically feasible and, if results are confirmed, economically attractive. Further pilot testing is planned.

Jan 1, 2002

By Donchak P. J, Champion D. C, Fordham B. G, Domagala J

The Hodgkinson Province forms the northern part of the Tasman Orogen and contains the most extensive outcrops of Silurian - Devonian rocks in Queensland. Deep-water, marine siliciclastic sequences (mainly turbidites) dominate most of the province except near the western margin where mafic volcanics and fossiliferous limestones characterise much of the succession. It is difficult to apply normal stratigraphic mapping techniques to the Hodgkinson Province because of extensive stratal disruption by numerous thrust faults, the general lack of stratigraphic and structural markers, and the unfossiliferous nature of much of the succession. Nevertheless, several distinct units have been delineated although their internal stratigraphy or boundary or superpositional relationships are uncertain. Ordovician strata, as well as two major unconformities have been recognised in the western part of the province. Several models have been proposed to explain the evolution of the Hodgkinson Province. Although there is no general agreement most recent researchers favour an extensional tectonic regime.

Jan 1, 1990