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By Riley S

Many regulatory bodies have, or are considering, guidelines that require rehabilitated mine spoils to be erosionally stable (satisfying quantitative limits) over specified design lifetimes. One of the problems facing the industry is that many of the computer models used for erosion assessment were developed for agricultural applications and are unable to predict the change in the shape of engineered landforms over extended periods of time. In particular, they cannot predict where valleys and gullies will develop in the landforms and how big or deep they will be. Furthermore, many existing models require considerable skill to use. A computer model (SIBERIA) developed by the first author, able to model this valley and gully development over long design lifetimes, and which is directly based on digital terrain maps is discussed here. Proposed rehabilitation strategies for waste rock dumps at Ranger Uranium Mine as assessed with SIBERIA are discussed. New features of SIBERIA of interest to the mining industry include the spatial distribution of erosion, deposition and gully development, and various measures of the quantitative risk of failure. A collaborative project with the Queensland Coal Association, involving the first author, aims to deliver these capabilities to the coal industry in a user-friendly package. The objective is the cost-effective rehabilitation of strip mines. Some preliminary results from this project are presented.

Jan 1, 1994

The Palaeozoic succession of Victoria contains one of the world's major gold provinces with a total production of 2500 tonnes of gold. Larger deposits, including Bendigo (over 800 tonnes Au), are related to Ordovician slates and greywackes, but a wide range of metamorphosed sedimentary and igneous rock types are host to significant gold deposits. Most, if not all, deposits demonstrate structural control, although the controlling structural features are variable between deposits: a majority of deposits comprise quartz veins. It is suggested here that a major factor in making Victoria such a gold-rich province might be a particularly high geothermal gradient in central Victoria during the Tabberabberan orogeny (360-380 my). This generated auriferous metamorphic fluids from underlying successions (?Cambrian) which migrated upwards along active structural pathways. One cause of gold deposition appears to have been fluid reduction by carbon, but other methods are suspected. This model is considerably simpler than the plethora of syngenetic, granite magmatic and lamprophyre-related models that have been proposed recently, but is in basic agreement with Cox et al. (1983). Exploration models for similar gold deposits both within Victoria and elsewhere should take account of the negligible evidence for a major syngenetic contribution to Victorian gold production, and the lack of any clear genetic relationship to particular igneous rock types. A real opportunity exists for new deposit types not identified by the early prospectors.

Jan 1, 1991

ALTHOUGH the mineral Stannite (Cu2S, FeS, SnS2 , also known as "bell 'metal" ore, tin pyrites, etc.) is found in various parts of the world, in only three iocalities has development proved it to exist in sufficient quantity to warrant the erection of treatment plants. Two of those mines are in New South Wales and one is an Tasmania. The writer will deal with the latter-the Conah mine, Zeehan, Tasmania, it being the most important and extensive occurrence so far worked. The Conah mine was first worked by a Tasmanian company for silver-Iead, and was fairly remunerative until the zone of secondary enrichment was passed through, when the lodes became too poor for further exploitation. During the time that the line was thus operated the stannite lode was discovered. It occurs in a graphitic slate, which, in common with the slates and spilites of the Zeehan field, is probably underlain by the stanniferous granite which outcrops two miles to the west. The Conah stannite lode is older than the galena lodes of the district, being faulted by one of the latter. Near the surface the lode was very rich.Shipments were sent out assaying 150 oz. of silver per ton, 20% copper, and 18% tin. An .apparently homogeneous sample of stannite, analyzed by the writer for the Tasmanian Geological survey, gave the following results:

Jan 1, 1915

AustraliaÆs record-breaking drought, efforts towards environmental best practice and the current commodities boom is demanding water use and reuse as never before. Mining practices, processing, the remote communities and support industries require vast amounts of specific quality water. Sustainability of water use has been a key factor in mine development, expansion of existing operations and increasing profitability of processes involving water. Developments in water treatment technology have enabled the use of a range of processes to produce this water reliably at ever decreasing costs. This increasing acceptance of new technologies has seen seawater desalination, recycling of plant wastewater streams, municipal wastewater reuse and others to become commonplace. Processes including seawater and groundwater reverse osmosis (RO), low pH RO, thermal desalination, high rate clarification, brine water treatment, ion exchange and other advanced treatment technologies are now used as part of mining operations. This paper surveys the trends in water treatment for the mining industry both in Australia and internationally with a review of technologies and case studies of operating plants. The key technologies are explained with an emphasis on the specific requirements for mining operations û unusual raw water, process and operations limitations, environmental concerns, as well as harsh climate. Case study information from several mining operations is included.

Jan 1, 2006

By D Alexander

For nearly 100 years, the flotation plant metallurgist has often wondered what is happening æbeneath the frothÆ. To assist in unravelling this mystery, new technology has been developed as part of the Australian Mineral Industries Research Association (AMIRA) P9 project, to measure gas dispersion characteristics (such as gas hold-up, superficial gas velocity and bubble size) in industrial flotation cells. These measurements have been conducted in a large number of cells of different types and sizes by researchers from the Julius Kruttschnitt Mineral Research Centre (JKMRC) and JKTech. A large database has been developed and the contents of this database are described in this paper. Typical cell characterisation measurements show a wide spread in values, even in the same cell types and sizes performing similar duties. In conventional flotation cells, the typical gas hold-up values range from 3 - 20 per cent, bubble sizes range between 1 and 2 mm, and superficial gas velocity ranges from 1 to 2.5 cm/s. The ranges of cell characterisation measurements given in this paper will enable plant personnel to compare their operation to other similar types of operations from around Australia and the rest of the world, giving opportunities for further improvement to flotation plant operations.

Jan 1, 2005

The Perth Mint receives gold and silver from various sources for evaluation and refining. The metals are received in many forms and vary widely in assay. Refining is carried out using the Miller Process and the and the resulting market quality bullion is sold in a range of weights and alloys to suit the international bullion market and public demand. INTRODUCTION The Perth Mint was established in the late nineties as a branch of the Royal Mint, London, to refine the gold from the newly established gold- fields in Western Australia. The branch was opened for business in June, 1899. After refining, the bulk of the gold was used in the manufacture of sovereigns and half-sovereigns. Nowadays, although most of the gold received comes from the W.A. goldfields, some gold is deposited by producers in other states and in Papua-New Guinea, as well as scrap and trade wastes from manufacturing jewellers and old jewellery from the general public. Silver is deposited in the form of old silverware, recoveries from-photographic processes etc. Gold or silver may be lodged at the Mint in person, through a bank or other agency or by registered post. Telegraphic advice is usually given when gold is sent by the latter, so that insurance may be effected.

Jan 1, 1982

By Curless JM, Power SG

Polymetallic hydrothermal veins of the Western Cascades are hosted in propylitically altered Tertiary volcanics of calc-alkaline affinity and (or) in nearby, altered, and compositionally similar plutons. Ores from shallow and now abandoned mines produced mostly gold and were considered to be of epithermal origin. However, recent discovery of breccia and porphyry types of Cu-Mo mineralisation and other data suggest that the deposits of this terrane vary systematically both regionally, south to north, and locally, high to low altitudes. The evidence includes changes in (1) size, composition, and complexity of plutons, (2) types of mineral deposits; (3) assemblages of alteration and ore minerals; (4) trace metal geochemistry of host rocks; and (5) fluid inclusion and sulphur isotope data. They collectively imply a consanguineous origin of vein, breccia, and disseminated-veinlet types of mineralisation by magmatic hydrothermal processes.

Jan 1, 1987

By D Fargher

BHP BillitonÆs Cannington operation began production in 1997 and is presently the largest tonnage and lowest cost single mine producer of both lead and silver in the world. The original design capacity was 1.5 Mtpa and this has progressively increased via a series of debottlenecking projects in both the mining and milling operations. In 2003, 2.39 Mt of ore was mined, whilst 2.31 Mt of ore was milled. In February 2003 Cannington received approval to expand the project to a sustainable capacity of 2.4 Mtpa. This resulted in underground development into the northern zone, upgrades to the concentrator, increased accommodation at site and power station capacity. The Cannington project development team implemented a partnership approach to the project. Fraser Osborn Engineering and Outokumpu Technology worked closely together with the Cannington team to meet all of the project constraints.

Jan 1, 2004

By A M. L Smith, W E. Dubbin, K A. Hudson-Edwards

Jarosites (KFe3(SO4)2(OH)6) are examples of minerals that are highly effective scavengers of toxic elements, and are abundant in acid rock drainage systems, acid sulfate soils, metallurgical wastes and other contaminated sites. The K, Fe and S sites can be filled by toxic elements such as Cd, Cu and Zn, but the mechanisms of this incorporation are not well understood.We have used atomistic simulation methods to model the jarosite (102) surface and its interactions with Cd, Zn and Cu, in order to understand the mechanisms by which these potentially toxic elements are incorporated into the K-jarosite structure. Our results suggest that incorporation via a defect complex consisting of an impurity cation at the K site charge balanced by a K vacancy stabilises the (102) surface in the order Cu>Zn>Cd.

Jan 1, 2008

By M Hino, Y Sasaki

Sustainable handling of municipal waste and sewage sludge has an important goal to recycle resources without supply of harmful substances to humans or the environment. The gasification mechanism of phosphorus from municipal waste and sewage sludge during the incineration process has been investigated to develop a phosphorus recovery system. Quadrupole mass spectrometer coupled to an electric furnace is applied to study the vaporisation behaviour of phosphorous gas phases from municipal solid waste (MSW) incinerator ash of sludge during solid-state reduction by carbon. Measurements are carried out in vacuum conditions of 2 x 10-6 Torrs and furnace temperature range 573 - 1773 K, at a heating rate of 7.22 K/minute. It has been found that most of the phosphorus is vaporised as PO2, P2 and P4, in agreement with thermodynamic estimation despite a shift in the temperature regimes.

Jan 1, 2006

By N Kusuma

Recoverable copper and gold estimates for resource models and ore control routing decisions at Batu Hijau were initially based on flotation testwork from several commercial laboratories. Due to the greater number of copper and gold assay grade available, regression relationships were developed between assay grades and flotation recoveries. Other recovery controlling variables such as oxidation and lithology were included to improve the regression models. With additional drilling, more flotation work was carried out and the regression models were revised to include the new flotation data, also alteration classification and in situ pH. The regression models were replaced in favour of spatially derived models for ore control and short range mine planning. To harness local variability in the block model, blast hole flotation testing is carried out in unison with routine grade assaying. Recovery data are processed (kriged) simultaneously with grade assay data prior to ore polygon delineation. Short range mine planning utilises this model in conjunction with a spatial recovery model derived from drill core flotation data. Long range mine planning utilises the æhybridÆ recovery model whereby the globally robust regression recovery models are overprinted by a spatial (kriged) recovery estimate where flotation data density is adequate (Phase II reserve).

Jan 1, 2002

This paper provides a brief fundamental insight regarding the fabric media concept for liquor filtration. The subject matter will be of interest to metallurgists and engineers with professional responsibility for world class design of solid liquid separation processes and efficient lowest cost operation of existing mineral process plant. Avocet Mining commissioned the worldÆs first mineral liquor clarification process incorporating a fabric media liquor filter at their Lanut gold mine in Sulawesi, in 2004 with design consulting provided by the Australian company SLS Technology Pty Ltd. Development of the technology continues with applied research focused on selecting textile parameters to apply filtration to a wider range of particle and contaminant types, higher solids concentrations, and different process liquors. Liquor filtration with the Fabric Media technology offers an array of attractive benefits. For Avocet Mining, filtration of pregnant liquor directly from the heap leach pad has enabled removal of the sediment pond and sand filters from the traditional process flow sheet, thus providing significant cost and installation time savings. Avocet Mining has recently expressed confidence in the technology indicating selection preference of the technology for the expansion at Lanut and for a new project. The application design window for the Fabric Media concept is extremely flexible with the technology now successfully applied to many different liquor chemistries and application objectives around the world. Potential cost savings for solid liquid separation process plant, such as counter current decantation circuits, clarifier vessels and thickener tanks can be calculated from laboratory measurements or pilot plant demonstrations.

Jan 1, 2008

By B L. Dickson, J H. Hodgkinson

The self-organising map (SOM) is an exploratory data mining technique that is both non-traditional and underutilised. Methodologies based on SOM tend to be data-driven and unsupervised, which makes them ideal to assist in the integrated analysis and interpretation of complex and disparate æmineral explorationÆ data sets. While traditional statistical multivariate approaches have difficulty with relationships that are non-linear and data distributions that are not normal, SOM-based data mining procedures are useful in these circumstances. In a SOM analysis each sample is treated as a vector in a data space defined by the variables; and measures of vector similarity, such as the dot-product or Euclidean distance, are used to order or segment a data set into naturally occurring populations. These groupings are positioned as nodes, or groups of nodes, on a 2D rectilinear representation of the multi-dimensional ædata spaceÆ, which is the æself organized mapÆ. While it is common not to include a sampleÆs locational information in the actual SOM analysis, such information can be used to display the spatial location of samples coded by their SOM node or cluster. If one finds there are coherent spatial patterns belonging to samples from particular nodes, or groups of nodes, then there is strong evidence that the technique is determining patterns and relationships within the data that have natural significance. Variations of the SOM technique may be used to perform broad categories of operations, including: 1. outlier identification û for samples belonging to various nodes or grouping of nodes; 2. function fitting, prediction, estimation or imputation û for calibrating relationships between variables and determining replacement values for missing, null or censored values; 3. clustering, pattern recognition or noise reduction û for determining the natural patterns within a data set; and 4. classification û for classifying samples into the clusters determined in three. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By F Sahlström, E M. Jolis, V R Troll, E Jonsson, K Högdahl, C Harris

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Bastnäs-type magnetite-skarn-hosted rare earth element (REE) mineralisations are located in the Palaeoproterozoic Bergslagen ore province, central Sweden, and occur along a ca 100 km long belt of 1.90–1.87 Ga metavolcanosedimentary rocks. Ten different Bastnäs-type deposits have been sampled in order to assess the origin of ore-forming fluids in these systems. Magnetite and quartz have d18O values ranging from -2.3 to +1.1‰ and +7.2 to +8.3‰ respectively. Mineralised carbonates have d18O values between +5.8 and +7.2‰ and d13C values between -5.4 and -3.3‰. Temperature calculations based on the O-isotope composition of mineral pairs, combined with available fluid inclusion data, suggest primary mineralisation at ca 650–400°C. For these temperatures, calculated equilibrium fluids have d18O values that range from those typical of magmatic fluids (+6 to +8‰) to lower values (down to +3‰). Variation in carbonate O and C isotope data are consistent with interaction between local Palaeoproterozoic carbonate rocks (d18O = +12.5 to +19.6‰ and d13C = -1.8 to +1.7‰) and fluids of a magmatic origin. It is suggested that the Bastnäs-type REE-magnetite mineralisations formed as a result of reactions between local carbonate units and high-temperature, magmatic-dominated hydrothermal fluids during 1.90–1.87 Ga (Svecofennian) syn-volcanic activity.CITATION:Sahlström, F, Jonsson, E, Högdahl, K, Harris, C, Troll, V R and Jolis, E M, 2015. O and C isotope study of Bastnäs-type rare earth element mineralisation, Bergslagen, Sweden, in Proceedings PACRIM 2015 Congress, pp 439–444 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Burman B. C

This paper describes studies into two particular aspects of the Lochiel deposit which formed part of feasibility level geot2chnical and hydrogeological investigations for proposed open cut mine development. The two aspects were depressurisation of thick beds of silt located through the profile and the determination of characteristics and origins of soil structure and their effect on pit stability. The studies were very detailed and multi disciplinary and highlight the integration of geology, geotechnics, hydrogeology and mining that is required for mine development studies. It is considered that as more marginal deposits are developed throughout the world the demands for efficient economic mining together with in- creasing scales of operation will require simi- lar types of studies. As such the studies pre- sented herein are likely to be a forerunner to a,emerging trend for development of open pit mines in difficult ground and water conditions.

Jan 1, 1986

By J Cook, S Pike, D Pridmore

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The application of high-resolution seismic reflection to map structure and/or mineralisation in hard rock environments has progressed significantly in the last decade. Improvements in equipment, field practice, processing and understanding has seen the seismic reflection technique emerge as a cost-effective tool for high-resolution three-dimensional structural and lithology mapping to depths far greater and with superior accuracy than other more conventional geophysical techniques.This paper outlines results and preliminary interpretation of 2D and 3D seismic reflection surveys aimed at defining fault zones and locations for quartz load development in favourable host lithologies at the Cracow low-sulfidation epithermal gold system in Queensland, Australia.As this is possibly the first time that high-resolution seismic reflection data has been used to define the structurally-controlled location of low-sulfidation epithermal gold mineralisation, an important aspect of this work was the derisking or due diligence steps taken prior to commissioning the full 3D surveys at each site. This included full wave sonic logging, vertical seismic profiling and trial 2D lines. Interpretation of the 2D profiles and the drilling of interpreted structure provided the confidence to proceed with the full 3D survey.The advantage of collecting 3D data extends beyond ensuring that the received reflections are located correctly in 3D space. The final 3D data cube can potentially map the entire fault network, thus highlighting flexures and changes in orientation of the structures both vertically and along strike, which is an important aspect in the deposition of gold and for direct targeting.CITATION:Smith, R, Cook, J, Pike, S and Pridmore, D, 2015. Application of high-resolution seismic reflection surveys to exploration for blind vein systems at the Cracow low-sulfidation epithermal field, in Proceedings PACRIM 2015 Congress, pp 77–84 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By R O. Laidlaw, J L. Mauk

The Coeur d'Alene mining district in northern Idaho, USA is the second largest producer of silver in the world. Mesothermal silver-lead-zinc veins occur in the metasedimentary rocks of the Belt Supergroup with five main types of associated hydrothermal alteration: 1) feldspar destruction, 2) hydrothermal bleaching, 3) carbonatisation, 4) sulfidation, and 5) silicification. Hydrothermal bleaching is characterised by hematite destruction with associated siderite and quartz veins and veinlets, coarse euhedral pyrite and magnetite. Bleached zones envelop both mineralised and barren veins and extend for metres to tens of metres into the wall rocks. Carbonatisation consists of addition of siderite, which occurs as veins, veinlets, stockwork, irregular blebs or spots, and coarsely disseminated grains, depending on the relative distance from the main vein structure. Siderite envelops nearly all mineralised veins, relates to all other alteration types and extends from several metres to tens of metres into the wall rocks. Pyrite and galena alteration dominate sulfidation and are associated with some mineralised veins. Pyrite alteration strongly correlates with siderite alteration and exists in three main forms: a) very fine-grained pyrite flooding, which can extend for metres to tens of metres into wall rocks; b) coarse-grained, euhedral pyrite, which is sporadic and associated with the redox boundary in hydrothermally bleached zones; and c) small isolated zones (6 - 15 cm) of medium-grained, subhedral to euhedral pyrite associated with pervasive siderite alteration. Where present, disseminated galena extends for metres to tens of metres into the wall rocks. Silicification is characterised by veins, veinlets, stringers, irregular patches and variable hardness in siltites and commonly appears in association with hydrothermal bleaching and siderite alteration. Although related to mineralisation, silicification is sporadic and in most places a clear envelope around mineralised veins cannot be identified.

Jan 1, 2001

By Grobler H. P, Chitombo G. R

Production blasting of Dc Beers Consolidated Mines Limited, Koffiefontein and Finsch Mines involves both uphole trough rings of 9 to I I holes and near vertical 360 degree compound rings of 42-54 holes. The rate of production from these stages is dependent upon being able to achieve a specified fragmentation size range and this has driven the derivation of blasting practices to consistently achieve this target fragmentation. At the Dutoitspan Mine, in Kimberley, where mining of the kimberlite pipe is by block caving, 100 per cent extraction of the undercut level by ring blasting is essential. If this is not achieved, pillars are formed which not only inhibit the efficient initiation of the caving process, but also concentrates load onto the extraction level, causing damage to draw points and pillars. These two case studies demonstrate the importance of achieving optimum blasting performance for downstream mining efficiency; ie fragmentation for increased productivity at Koffiefontein Mine and 100 per cent undercut extraction for efficient initiation of the caving process at the Dutoitspan Mine. The case studies also serve to highlight the long road towards blast optimisation taken by De Beers Consolidated Mines Ltd (Koffiefontein. Finsch, Premier and Kimberley Mines) since 1989.

Jan 1, 1995

A non-contacting under-belt capacitance and gamma-ray backscatter technique has been developed for the on-line measurement of moisture in coal. In this technique, moisture was correlated with radio frequency susceptance and conductance determined using an under-belt capacitance sensor in which a fringing electric field Interrogates a layer of coal on the conveyor belt directly above the sensor. To compensate for variations in the density and thickness of the coal layer, an under-belt gamma-ray backscatter gauge was used to measure an equivalent volume of coal.A plant trial of the technique was conducted at Stockton Borehole Colliery, SW Australia, where the gauges were installed on the coking coal product conveyor. Product moistures, in the range 7 - 14%, were determined with r.m.s errors of 0.50 and 0.25 wt% using on-belt and static off-belt gauges, respectively. The difference in the on-belt and off-belt gauge measurement accuracy was attributed to sampling errors in the calibration of the onbelt gauge.

Jan 1, 1989

Polarization phenomena associated with the use of an agitated bed of particles as an electrode for metal deposition were studied. The concentration polarization at this type of electrode is much smaller than that occurring at a fixed or moving electrode surface. Agitated particle electrodes can be used to electro-reduce copper from solutions over a wide range of concentration and at cur·rent densities up to 2000 AIsq. ft. of bed cross section.

Jan 1, 1971