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The copper and zinc contents of herbarium specimens of 11 of the 12 Australian species of Polycarpaea were determined in order to establish background and anomalous values of potential use in biogeochemical prospecting.Cumulative frequency curves were used to establish appropriate threshold concentrations for six species including the "copper plant"' P spirostylis. Collection localities of Polycarpaea specimens with anomalous copper or copper-and-zinc values are under investigation.

Jan 1, 1978

By L Terrusi

The Bungaroo Valley hosts a concealed Tertiary channel iron deposit (CID) along a 17 km stretch of its length. Bungaroo Valley is approximately 0.5 km wide upstream at its easternmost extent, and 3.5 km wide downstream where it joins the Jimmawarrada Creek. The valley follows the axial trace of an anticline that plunges gently to the southeast, and the CID infills the valley. Mineralisation extends to a depth of 230 m below the surface, and almost the entire deposit occurs below the water table. Bungaroo Valley cuts through the Buckland Hills and is bounded to the north and south by steep scarps capped with the resistant Dales Gorge Member of the Brockman Iron Formation. Basement rocks are believed to be mostly Wittenoom Formation shales and dolomites, with Mount McRae Shale and Mount Sylvia Formation also present. Deep, localised depressions appear at the base of the CID sequence towards the north edge of the upstream section of the valley, while downstream the basal CID contact is relatively flat and shallow. In both cases the profile of the CID surface closely mirrors that of the basal contact. The localised depressions seen in the upstream basal CID contact produce significant variations in CID thickness of up to 100 m over short strike distances. This uneven palaeotopography is most likely due to eddying and waterfalls forming within the riverbed prior to CID deposition during a time when the water table was much lower than at present. It may also be associated with possible karsting in an underlying dolomite unit and subsequent syn- or post-depositional collapse of the overlying CID. The irregular basal contact of the Bungaroo CID sequence has implications for mining in terms of pit design and resource accessibility.

Jan 1, 2007

The Effect of Ionic Strength of Plant Water on Valuable Mineral and Gangue Recovery in a Platinum Bearing Ore from the Merensky Reef

Sep 13, 2010

By Parr JM, Scott SD, Herzig PM, Gemmell JB

PACMANUS is an actively-forming seafloor analogue of volcanic-hosted massive sulfide orebodies, situated on the crest of an andesite-dacite-rhyodacite ridge overlying rifted older arc crust in a back-arc basin. Hydrothermal deposits range from Mn-oxide crusts to Cu-Zn-rich massive sulfide mounds and chimneys containing significant Au and Ag. Preliminary data suggest a substantial magmatic component to fluids and metal sources, and we speculate that PACMANUS is the cap to a complete hydrothermal system including subvolcanic and intrusive-related mineralisation.

Jan 1, 1995

Project cost control procedures and computer systems have enjoyed a successful and simple relationship over the past decade, thanks primarily to the proliferation of portable computers or PC's. Prior to the introduction of this technology, project control was largely a manual and somewhat onerous task of historical data compilations, with little time available for dynamic forecasting, staged planning, or pre-emptive cost control. Automated systems developed during this era were resident on "Heavy Iron" or mainframe computers and were expensive to maintain and operate. Use of these early systems was limited to large engineering, construction, and industrial concerns with the economies of scale and funding required for their successful application. Systems were either designed for critical path analysis or task scheduling, but rarely integrated with the other, much less cost control.

Jan 1, 1990

By K Grohs, A Satriawan, S R. Pearce

Martabe gold and silver mine is operated by PT Agincourt Resources (PTAR) and is situated in northern Sumatra and comprises several deposits in steep terrain, and in a tropical climate, that are required to be developed in the optimal sequence for the best possible Net Present Value (NPV) return on the project. In addition, the waste rock from excavations and tailings from processing is a by-product to be scheduled and used for a number of purposes identified as part of life-of-mine planning. These uses include construction of the current integrated tailings storage facility (TSF) as well as future engineering construction and waste disposal projects which includes plans for a program of in-pit backfilling. These plans need to be aligned to ensure the waste rock and tailings can be contained relative to the production rate. Given that the site will have multiple open pit voids upon cessation of mining activities opportunities for integration of in-pit disposal of mine waste have now been assessed with technical studies to review the practicality of the approach with respect to operational challenges and conformance with closure planning requirements. This includes assessment of disposal of waste rock, tailings (including consideration of filtered tailings) and co-disposal of waste rock and filtered tailings.

Aug 2, 2023

By Torabi S. R, Daly C. R

Wind blast is the sudden movement of air displaced by the massive collapse of roof rock in underground openings and is experienced as a high velocity flow of air through adjacent workings. The initial flow in the outbye direction is often followed by 'suck back', that is a reverse flow of air towards the newly created void. As part of the Wind Blast Project, undertaken by The University of New South Wales, Department of Mining Engineering, a physical model was constructed. One of the functions of the laboratory wind blast model is to provide insight into the dynamics of the interaction between the falling strata and the air being compressed below. During a collapse, some air is expelled into the surrounding roadways while the remainder penetrates towards the top of the roof elements. In this paper two aspects of the rock mass properties which influence the phenomenon are considered: - Flow paths through the falling roof element, ie the permeability of the roof element; - Bed separation prior to the fall which introduces a void above the roof element. A series of tests was carried out utilising the physical model in order to investigate the relationships between the flow of air through the simulated roadways, the variations in gauge pressure above and below the falling roof element, and the acceleration and terminal velocity of the latter, all as a function of the flow paths through the roof element and of the extent of the void above. The results of comprehensive tests using the wind blast physical model suggested that the time history of outbye air flow in the simulated roadway comprises two distinct phases. a) A primary phase, characterised by a high velocity flow of air which exhibits a peak and corresponds to the period during which the roof element is accelerating. The peak air velocity is related to the acceleration of the roof element. b) A secondary phase, characterised by a residual air flow of a lesser velocity than in the primary phase and corresponding to the period during which the roof element is falling at its terminal velocity. The velocity of the residual air flow is directly proportional to the terminal velocity of the roof element. In a monolithic collapse of a roof element it was shown that the presence of flow paths in the roof element increased the air velocity in the roadway in both the primary and the secondary phases. The presence of an air-filled void above the roof element, on the other hand, influenced the air velocity only in the primary phase by increasing the peak air velocity. The overall duration of the process was however decreased as a result. 'plug type' collapses, where roof failure extends to the ground surface, potentially generate the highest peak air velocities likely to be encountered during wind blasts.

Jan 1, 1995

By A Jha, R Merz

The substantial growth in world demand for Queensland coking coal has seen a number of new coal mine developments in the Bowen Basin in recent times. The Bowen-Broken Water Supply Scheme (BBWSS) is presently based on water supplied from Eungella Dam and storages at Collinsville to two major pipelines. In early 2004, three successive years of well-below average rainfall had left Eungella Dam at critical levels, threatening the regionÆs mines, which rely on it for their essential water supply. SunWater noted that without significant inflows into Eungella Dam, or the development of a new water supply to the region, existing mines would be severely restricted in water supply, and downstream economic impacts to the region would follow. SunWater investigated the opportunities for additional supply capabilities, including combinations of off-stream storages, additional pipelines, and raising Eungella Dam. An off-stream storage (OSS) was selected as being the preferred option to improve the reliability of the system and head off impending falls in announced allocation for the system. The integrated quantity quality model (IQQM) is the Queensland GovernmentÆs preferred model to define and assess total catchment performance against water security and environmental objectives. Modelling of the performance of the water supply system, with and without the proposed OSS, was required to provide justification to the customers of the system that the OSS was in fact required, and also to optimise the configuration of the OSS within time and budgetary constraints. In the case of the BBWSS, no environmental base flows are dictated by the Department of Natural Resources, Mines and Water (NRM&W) at present and the primary reason for applying IQQM was therefore to investigate the trade-offs between supply options and reliability. SunWater produced IQQM outputs for a range of scenarios for the proposed off-stream storage, and these IQQM outputs were then used as input to a decision-support tool based on the GoldSim modelling package. The GoldSim model was then applied to investigate the water supply reliability for high priority users resulting from various existing and/or proposed water supply infrastructure configurations coupled to the hydrologic system. The GoldSim model included the ability to assess the long-term water supply reliability impacts for each of the water supply end-users for a wide range of user-defined scenarios. Non-technical model users were able to change the size of the off-stream storage, pipeline capacities and assumed climatic conditions and test for themselves the relative benefits (in terms of water supply reliability) of different infrastructure configurations under consideration. The decision tool was of significant benefit in assisting the decision process to SunWaterÆs mining customers. These customers needed to decide if they felt that the increased reliability in their water supplies from the system that would be created warranted the estimated increased charges that would require to be levied to recover costs of the new infrastructure with appropriate profit margins. The conjunctive use of IQQM and GoldSim was successful in demonstrating the impact of both hydrological and non-hydrological issues on the future water supply reliability in the BBWSS and resulted in a decision to proceed with the construction of a new OSS.

Jan 1, 2006

By M Haest, O Dominguez, D Mittrup

Technological innovations and emerging analytical capabilities are transforming the way drill samples are analysed, with real-time mineralogical analysis made possible. In addition, new business/technical requirements are challenging long standing processes to incorporate more sources of information during planning in order to improve compliance to plan during mining and processing. Unfortunately, the new sources of information that are added do not always have adequate protocols in place to ensure quality data is collected.Spectral data covering the visible – near – short wave – midwave – longwave range are routinely collected by the Geoscience and Exploration department at BHP Billiton Iron Ore for accurate mineralogical identification. These data are used for geological interpretations (logging and modelling) and prediction of physical variables (metallurgical and geotechnical properties).This paper introduces how sampling and quality assurance / quality control concepts have been applied in the spectral data process. The described routine for sampling, data collection/management and reconciliation has been developed to track system precision and accurately and consistently ensure the data is of high quality before it is used across the mining chain.CITATION:Mittrup, D, Dominguez, O and Haest, M, 2017. A new approach to implement quality assurance and quality control to technological innovations – quality of spectral data capture and processes in the minerals industry, in Proceedings Eighth World Conference on Sampling and Blending , pp 265–270 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

Dr Eric Bumstead is to be commended for his recent paper on gold analysis, published in the March 1984 Proceedings. It is not often that someone in industry, rather than academia, takes the time to collect and report on such a volume of data, data which is of interest to everyone involved in gold exploration and development.After reading the paper I felt, as a geochemist and as ayer, that there was another side to this whole question of analysis that few people are aware of, i.e. the problem facing a laboratory and how the laboratory can try to give the customer maximum value for money spent.Analyses for gold are carried out for different reasons, depending on the aims of the geologist or metallurgist who presents the samples. These can broadly be separated into three classes, to answer the following questions.1. "Is there any gold in this sample?"2. "Approximately how much gold is there in this sample?"3. "How much gold is there in this sample?"In every case there is a different balance between accuracy and precision, cost and avoiding chemical problems. By "chemical problems", I mean such possibilities as samples containing high levels of sulphides, gold present as tellurides, cyanide being present, contamination with mercury, and other mineralogical oddities, plus problems such as samples containing grease.There is no such thing as one assay to cover all possibilities.Samples in category I come mostly from early stages of exploration.There are often large numbers of samples, their mineralogy is not well known and hence chemical problems could exist, but the explorer wants assays at a minimum level of precision and expects minimum cost. These characteristics do not easily come together, for although the precision required is low, the accuracy required is high at low levels. A small positive result when the true answer is nil could lead to a fruitless search and a waste of money. Conversely, a nil result, when the true answer is a small but significant level of gold, could lead to the passing over of an area that may warrant further work.Because there are conflicting requirements for this type of assay, the methods chosen must be a compromise and different assayers will balance these requirements differently and come to different conclusions. The methods cover sample preparation, assay sample size and variations in assay techniques.

Jan 1, 1984

By J P. Evert

Didipio gold-copper mine operation is situated in the island of Luzon, approximately 270 km north of Manila in the Philippines, in an area of high seasonal rainfall. The hydrogeological water flow model implied that there would be high connectivity between regional structures and underground operations. This model predicted that underground mine groundwater inflows were expected to quickly rise as the decline progressed to a peak of 510 L/s. Designing a capital pump station to deal with 510 L/s has its own challenges, however developing the decline down to the required level, always dealing with 300 L/s of water and constructing the pump station is extremely challenging and required a robust water management plan and mine design. When dealing with expected high volumes of water, underground mine design and scheduling plays a key role in protecting electrical infrastructure, equipment, secondary pumps, and the decline from flooding. A good drainage system and controlled dewatering plan is essential for safety and progress. This paper details the dewatering techniques and mine designs required to accomplish decline development with high water inflows as used in the Didipio project. It will describe the learnings and outcomes that are achievable with a flexible design, as new structures are mapped, and water intersections are increased. It also highlights the potential for adaptability in mine planning to provide evolving improvements or to evade problems that are expected from the constant reconciliation of data recorded during development.

Mar 29, 2023

FOR some time it has been recognised by the Metallurgical Staff that the presence of pyrite in the ore was adversely affecting the grades of the flotation concentrates.Following experimental work, it was decided to change over from the acid circuit in the mill to an alkaline circuit. The following description sets out the procedure adopted, -and the results obtained when such change-over was made.The Zinc Corporation ore consists mainly of galena, marmatite, calcite, and quartz, with smaller quantities of pyrite, fluorspar, and rhodonite.A clean specimen of marmatite picked from the ore assayed 53.4% zinc, and 10% iron, with no lead or insoluble. However, as zinc concentrates have been, at times, produced in the plant assaying over 53% zinc, and with only 8.7% iron, apparently the picked specimen of marmatite did not represent an average composition.The average would probltbly be between 8 and 9% of iron, and from 53.5 to 54.5% of zinc. It is obvious, therefore, that from this ore it is not possible to produce zinc concentrate of a higher grade than this average figure.In the Colorado School of Mines Quarterly for April, 1928, Vol. 23, No. 2, on page 47, we find the following statement:As the zinc in the ore exists as marmatite, which contains approximately 54.5% zinc and 10% iron, 49% zinc in the concentrate may be considered high.This statement refers to the ore treated in the Sullivan concentrator, owned by the Consolidated Mining and Smelting Company of Canada Limited.

Jan 1, 1930

By M J. Sale

The Epithermal and Mesothermal Gold Prospectivity Modelling Projects recently completed by Crown Minerals provided explorers in New Zealand with a new compilation of historical exploration data combined with new geological information from the GNS QMap 1:250 000 scale mapping project. These data were used to produce predictive mineral potential maps for gold mineralisation in New Zealand. The aim of these projects, which was to stimulate mineral exploration and investment in exploration, has been successful with new companies acquiring new tenements and committing significant exploration expenditure to exploring in New Zealand in the coming years. The projects were undertaken at a national scale and consequently not all exploration data were compiled into the prospectivity models. HPD New Zealand Ltd recognised the value of the prospectivity modeling work and committed exploration funds to continue the modelling process started by the projects. They recognised the need to compile the remaining data and run the models again to allow detailed exploration targeting.

Jan 1, 2004

High pressure (-1.2 GPa) Early Cretaceous granulite facies orthogneisses in Fiordland, New Zealand are in tectonic contact with a cover sequence comprising mid-Palaeozoic amphibolite facies metasediments, subordinate metavolcanic rocks and syntectonic granitic orthogneisses. This cover sequence and the underlying granulites constitute upper and lower crustal plates of a mid-Cretaceous metamorphic core complex whose emplacement was linked to continental rifting and the Late Mesozoic breakup of the Pacific margin of Gondwana. Exhumation of the lower plate granulites occurred in two stages. The first stage was associated with extreme attenuationand tectonic denudation of the cover sequence accompanying emplacement of the core complex, leading to rapid uplift of the granulites but without generating the large volumes of Fiordland-derived sedimentary detritus normally expected if uplift and erosion were the only factors involved in unroofing the granulites. Final uplift and exposure of the granulites at the surface occurred mainly during the last 10 Ma in response to transpression across the mid-Tertiary Alpine Fault and/or the obduction of Fiordland continental crust over oceanic crust of the Tasman Sea.

Jan 1, 1990

By B Veera Reddy

For thick seam extraction, the Blasting Gallery (BG) method is ideal for obtaining the maximum percentage of extraction at fast rates. The continued use of this mining method is threatened by strata control and spontaneous heating problems. The strata control problems are managed, to some extent, by supporting the roof with cable bolting and roof bolts of 2.5 m length and with regular induced blasting. However, a number of BG panels were sealed off prematurely due to spontaneous heating problems, losing 1.12 million tonne of coal. The use of compressed CO2 for controlling mine fires is not uncommon in the coal mining industry, but its use is something new for controlling active spontaneous heating in a BG working panel goaf. This method was attempted at the BG I/8 panel of the Godavarikhani (GDK) 8 Incline, Singareni Collieries Company Limited (SCCL). The spontaneous heating was effectively controlled and the remaining coal in the panel was completely extracted by continuous flushing of carbon dioxide (CO2) into the goaf for 40 days. One thousand and twenty four CO2 cylinders, each of 45 kg at 80 bar pressure were flushed into the goaf at the rate of 25 to 30 cylinders (350 m3 of CO2) per day. A quantity of 35 510 tonne of coal was extracted during the period from 30 July 2002 to 7 September 2002. The main objective of this paper is to present the complete process of controlling the spontaneous heating by CO2 flushing and to report on the study of the behaviour of gases and their analysis. The unique experience of controlling the active spontaneous heating in the working Blasting Gallery I/8 panel goaf at GDK 8 Incline with CO2 flushing (till the completion of the panel) will go a long way in establishing a working procedure for handling fire/spontaneous heating problems in BG panels.

Jan 1, 2005

By Gray J, Krouse HR, Changkakoti A, Kwak TAP

The Dachang tin field with more than one hundred million tonnes of ore at 1% tin and 3% Zn is one of the largest tin fields in the world. It comprises five carbonate replacement tin deposits, of which the Changpo deposit containing about 80 million tonnes of ore at about 1% tin is the largest deposit. The deposit, hosted by middle Devonian limestone, argillaceous limestone and black shale, is genetically related to the Longxianggei granite.The oxygen, hydrogen and carbon isotope data of minerals, rocks and fluids suggest a magmatic fluid which evolved during the crystallization of the Longxianggei granite. Mass balance calculations show that the depletions observed in 180 and 13C values of calcites from the ore bodies to the country rocks were due to continous isotopic exchange reactions between the magmatic fluid and the marine limestones at different W/R ratios and between 300 and 600¦C.

Jan 1, 1990

By P Collins, C Sheriff

The Sand Queen gold mine is a typical Archaean narrow, high-grade gold quartz lode deposit within a shear hosted system. Initial mining during 1904 - 1948 produced 181 659 ounces of gold from 248 564 tonnes of ore milled at an average production grade of 22.7 g/t Au, which equates to a minimum of 750 ounces per vertical metre. The current mining operation is using the old Sand Queen main shaft to access the Sand George deposit, which is a narrow quartz lode system discovered in the same shear structure along strike to the south of the Sand Queen mine workings. Current underground resources contain 360 200 tonnes at a grade of 11.8 g/t Au for 136 500 ounces. Mining is scheduled to produce 20 000 ounces of gold annually. Re-opening of the Sand Queen mine and underground development of the Sand George lodes has revived several grade control issues relevant to a narrow, ænuggettyÆ gold lode mining environment. These include the dependence of assay grade of individual samples upon a number of factors, including how and where a sample is collected, how and where it is analysed, and how grade data is used to estimate an æaverageÆ grade. Ideally, the only way to achieve an acceptable estimate of ætrue gradeÆ is to mine and mill a large parcel of ore (eg >100 tonnes) from each lode or ore type. In a mining operation producing relatively small tonnages from a number of separate ænuggettyÆ gold lodes, availability of resources and operational constraints may preclude intensive sampling for predictive grade control. At the Sand Queen mine, one of the key issues has been to establish a reliable system for estimation of gold grade with which to reconcile milling data. Extensive use has been made of detailed geological data to understand the grade distribution within individual lodes and between lodes, so as not to rely solely on assay results.

Jan 1, 2008

By R Kerrich

Early-Archaean (3.26 Ga) volcanogenic massive sulphide (VMS) deposits located within the low strain and sub-prehnite-pumpellyite metamorphic-grade Strelley greenstone belt, East Pilbara, Western Australia, contain exceptionally well preserved sulphide textures which are directly analogous to those of sulphide chimneys formed by black smokers at present day submarine hydrothermal vents. The VMS deposits are associated with seafloor alteration zones in and below silica-carbonate laminites, at the top of tholeiitic to calc-alkaline intermediate and felsic rocks. VMS mineralisation comprises stratabound Zn-rich sulphide lenses with significant Cu and barite, and variable Pb and Ag, above Cu-rich stringer zones, all of which are similar to Phanerozoic polymetallic or Kuroko VMS deposits. Sulphide-sulphate mineralisation implicates hydrothermal discharge into sulphate-bearing ocean waters, ruling out a globally anoxic Archaean hydrosphere. The volcanic rocks and co-magmatic sub-volcanic intrusion hosting the VMS deposits are characterised by the conjunction of LILE>LREE>HREE, and Phanerozoic La/Yb with negative normalised anomalies of Nb, P and Ti, consistent with derivation via subduction zone hydrous metasomatism fusing the mantle lithosphere.

Jan 1, 1995

By A B. Christie, S C. Cox

Effective land-use planning requires accurate knowledge of mineral resource potential. Mineral companies during reconnaissance exploration, feasibility investigations and mine development also use this type of analysis. The Institute of Geological and Nuclear Sciences is undertaking a two-year project reviewing the resource potential of the West Coast of the South Island of New Zealand. Spatial prospectivity models have been developed as part of this resource assessment process, using computer based statistical pattern recognition techniques to delineate areas that are prospective for mineral deposits and to test deposit genesis models. Digital GIS data-sets of mineral occurrence were correlated against geology and exploration information. The distribution of mesotherrnal shear zone gold deposits in the Reefton Goldfield, were examined against geological data-sets from both the regional (QMAP) and local prospect-scale mapping. Weights of evidence analysis generated a correlation matrix that highlights relationships and degrees of association that might otherwise not normally be recognised.   Mesothermal shear zone gold deposits have strong positive spatial correlations with Greenland Group host rocks and areas with moderate to high quartz vein densities; moderate-strong positive correlation with regions <500 m from folds, with regions <600 m from faults and five to eight kilometres from granite contacts; moderate correlations with Ntrending fault and fold segments; and no/weak/poor correlations with fault intersections, fold-fault intersections, bends in regional structures and magnetic and radiometric data. The regional and prospect scale data sets give different results, with the more detailed prospect scale mapping giving generally better correlations. This emphasises the value of detailed geological mapping in the exploration process.   Maps generated by prospectivity modelling consistently highlighted areas of known mineralisation and generate targets where follow-up investigation is warranted. The prospectivity per unit area provides a measurable value that should change as new information comes to hand and, in addition to highlighting targets, can be used to measure the impact of increased exploration expenditure and assess the effectiveness of exploration investment.

Jan 1, 2001

FROM time to time articles have appeared in the technical press on the interesting subject of surface combustion. The theoretical part of the problem has, for practical purposes, received ample consideration in those articles, but the number of practical applications of surface combustion referred to has generally been very small.It is the writer's object to review some recent developments in surface combustion, and also to try to arrive at an estimate of its advantages and possibilities. It is not necessary for this purpose to dilate upon the phenomenon of surface combustion itself. Many interesting things have been said on the subject by Pro£. W. A. Bone, of Leeds, to whose researches the recent developments are largely due. A few illustrations may make clear what is meant by surface combustion.Prof. Bone, in an experiment, took a platinum crucible, which he heated in the flame of a Meker-burner. Then he turned the gas off for a second, and, opening the stop-cock again, allowed the combustible mixture to impinge upon the crucible, thetemperature of which was still well below the ignition temperature of the gas. Although no flame was visible at this stage, it was soon clear that, nevertheless, the gas and air had continued to combine, as the crucible would attain a red heat after a few seconds.Another instance of surface combustion was shown by a Mr. Fletcher, in 1882. He placed an iron ball, weighing 3 lb., on a slab of fireclay, heated it for a few seconds with a blow-pipe, and blew the flame out, leaving the gas-mixture still...

Jan 1, 1915