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Largely inherited from the past and from strictly internal laboratory use, the certification of reference material using round-robin assaying is often insufficient for the use made today for external assay laboratory control by client parties. Certification often needs to be revisited on the basis of existing round-robin data, especially to derive reproducibility parameters to the end of establishing probabilistic performance gates for operational error detection on a batch per batch basis (ie batch-ærejectionÆ). The most common difficulty arises when only a few certification samples have been analysed in one single batch by each laboratory, so that the round-robin data do not contain the full variability that needs to be quantified. Existing certification data sets from properly submitted round-robin samples were studied using analysis of variance to derive a remedial method, leading to the proposal of default correction factors to restore full variability estimates when no other avenue is available.

Jan 1, 2008

The metallurgical works of the Electrolytic Zinc Company is situated on the Derwent Estuary, approximately five miles north of the city of Hobart and near a relatively dense housing area. Zinc concentrates, consisting chiefly of zinc and sulphur, have been roasted at Risdon for 53 years;- recently at rates of 1, 100 tons per day. The zinc content of the ores is converted to zinc calcine (ZnO), which is a dusty material. The calcine is leached with acid to form zinc sulphate, which is then electrolysed to make zinc. The sulphur is oxidised during roasting to sulphur dioxide, part of which is converted to sulphuric acid and part is dissolved in estuarine water which is then discharged to the Derwent Estuary. Photographic slides were exhibited showing the unaffected green flora of the nearby hills, of clear exit stacks, of green lawns, and of a w ll lrcnt nines hnlP anlf nniir.qa within the Wnrka hnnnrla_rv_

Jan 1, 1971

Low-grade manganese ore from Sandur, India containing 28.2 per cent manganese and 20.9 per cent iron was roasted with sulphating agents, viz ammonium sulphate and sulphuric acid. The effects of temperature of roasting (300 - 800°C), time (15 - 120 minutes) and amount of sulphating agent (0.5 to 2.5 times stoichiometric amount) were studied. Under optimum conditions, it was possible to extract 92 per cent manganese with 0.5 per cent iron at a temperature of 700°C for 90 minutes duration with stoichiometric ammonium sulphate. Further increase in quantity of ammonium sulphate has marginal effect on manganese extraction.Similar studies were carried out with sulphuric acid, and an extraction of about 87 per cent manganese with similar iron contamination was achieved at a temperature of 700°C for 60 minutes duration with stoichiometric quantity of the reagent. Selective extraction of manganese with respect to iron is discussed.

Jan 1, 1996

Trade unions are people. As organisations they exist to represent the needs and interests of their members; that is the workforce. Thus one of the underlying objectives of the trade union movement has been and will continue to be: achieving from management recog- nition that the labour input to the production process - whether that be in the factory, office or service context - is made up of individual people who can not be treated as just another factor of production. The essential difference between labour input and other factors of production such as capital and raw material is the "humanness" of the individual entities which make up a firm, company or industry's labour supply. Recognition of the "people" input to the production process has essentially two aspects: humanisation of the workplace and the treatment of labour as human beings who have a role to play both within the workplace and within broader society.

Jan 1, 1982

During the 1960s chalcocite ore was mined from the Black Rock open cut. A large amount of this uneconomic material was not treated by the No 3 Concentrator at the time and as a consequence a surface stockpile was created which contained 750 000 tonnes of material at an average of 1.5 per cent copper.Laboratory trials indicated that due to oxidation, an average of 25 per cent of the copper was water soluble and the remaining copper was leachable using a sulphate/ferriclbacterial leach. On the basis of these trials it was decided to investigate the feasibility of producing copper via a leach SX-EW process. The investigation proved the process was feasible, so began the design, construction and commissioning of a 10 tpd (cathode copper) Copper Leach SX-EW Pilot Plant. CMPS Pty Limited in a joint venture with John Holland Engineering Pty Limited were awarded the turnkey contract for the design, construction and commissioning of the Pilot Plant.

Jan 1, 1993

By Staude W, Rosser A

Due primarily to the publication of the Fitzgerald Report the impact of taxation on the mining industry and the amount of taxes actual- ly paid by the industry have become items of intense debate. However, the discussion has been governed more by impassioned rhetoric than considered logic. It is equally as wasteful to the economy for the mining industry as a low cost efficient export earner to be punitively taxed, as it is for the industry to be given excessive taxation assistance. A comparison of the effect of five tax- ation policies on the cash flow of a capital intensive mining project is presented. The policies considered are Liberal 1969, Liberal 1976 with and without the coal levy, Labor 1975 and Labor 1976. The mining project used in the analysis is modelled on published estimates for the proposed Nebo coal project. The analysis is equally applicable to any large mining or petroleum development.

Jan 1, 1977

In the past two decades the global metalliferous mineral industry has trended away from pyrometallurgical (pyromet) and towards hydrometallurgical (hydromet) technologies including biometallurgical (biomet) processes. Pyromet, biomet and hydromet technologies have all developed considerably over this period. New projects have been biased or directed by legislation towards supposedly cleaner and greener hydromet and biomet technologies. The environmental cost and energy cost of pyromet production processes for copper and cobalt are compared with comparable hydromet processes using Life Cycle Assessment (LCA). The æreal costÆ of the global warming obsession and negative public perception of pyrometallurgy include greater carbon dioxide emissions and energy consumption per unit, associated with current hydromet technologies. Specific examples for copper and cobalt produced via the different routes are provided. The poor science involved with the global warming hypothesis is discussed. The use of LCA with sensitivity analysis as a decision making tool for mineral processing projects and technology developers is discussed.

Jan 1, 2004

By S Vianna

Mineralogical information obtained from plant surveys is subject to errors, both due to sampling and experiment. To reduce these errors, and to ensure that information is consistent, a data reconciliation model has been developed for mineralogical data. Its capability includes mass balancing size data, total assays, assays within size-classes and liberation data. Unlike any other mass balance package, this package also allows reconciliation of the complex mineralogical information. For example, particles cannot simply be treated as binary, but consist of combinations of many minerals. Hence the distribution of mineralogical information is multidimensional and the mineralogical distributions are referred to as multiphase. In this paper, the different levels of mass balancing are explained, including how to mass balance liberation data. Furthermore a new technique based on probability theory can be used to infer distributions even when there is insufficient information to perform a mass balance, and this technique is also explained. Results for various stages are given.

Jan 1, 2002

The activiltion of sphalerite with electrolytically generated copper ions from a copper electrode instead of the usual practice of the addition of copper sulphate was studied in the laboratory. A large surface area of copper was provided by lining three sides of a bench flotation cell with copper sheeting. The lining was connected to the positive terminal of a low voltage d.c. source, and the cell impeller to the negative terminal.Sphalerite was effectively activated by this arrangement and was subsequently floated using xanthate as the collector.Flotation results comparable to those obtained with 1 lb/ton CuS04.5H20 (0,255 lb/ton copper) were obtained using 0·1062 lb/ton of electrolytic copper and 0·488 kWh of electrical energy. The wastage of copper due to the formation of insoluble precipitates was found to be dependent on the length of time the current was passed. Maximum current was passed for the shortest time to minimize wastage.

Jan 1, 1973

By E House, V Lisitsin

Recent whole-rock geochemical data from nearly 900 fresh drill core and underground samples taken from seven central Victorian gold deposits confirm the presence of distinct and identifiable primary alteration haloes surrounding the deposits. Ferroan carbonate alteration extends for up to several hundred metres away from turbidite-hosted gold mineralisation outside of contact metamorphic aureoles. A less distinct phyllic alteration zone can be identified using geochemical molar ratios or short wave infrared analysis. It generally overlaps a sulfidic halo characterised by disseminated pyrite and in close proximity to mineralised structures, arsenopyrite. The extent of the sulfidic halo can be traced using low-level analysis of pathfinder elements such as S, Au, As and Sb. Recognition of these alteration features enlarges the target for exploration and provides a tool by which drilling can be directed towards mineralised structures. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By B Hall

The authors have undertaken many independent mine optimisation and operational improvement projects at Australian and international mining operations over the past decade. This work has provided an understanding of the underlying practices responsible for the good long-term performance of some operations, and the failure of others to achieve their objectives. Good long-term performance, and value creation can be achieved through a logical and rigorous process of identifying the optimal mine plan (æThe PlanÆ) that delivers the corporate goals, establishing appropriate performance measures that are aligned with these goals, and ongoing monitoring of compliance with the established targets to ensure the operation reliably achieves The Plan. A number of practical methods have been developed and implemented to assist mining operations deliver their corporate goals. This paper outlines some of these methods, providing some fundamental guidelines that will assist in the establishment, and reliable achievement of The Plan that delivers the corporate goals.

Jan 1, 2006

By H Durrant, P I. Corke, J Cunningham

This paper reviews the state-of-the-art in the automation of underground mining vehicles and reports on the development of an autonomous navigation system under development through the CMTE with sponsorship arranged by AMIRA. Past attempts at automating LHDs and haul trucks are described and their particular strengths and weaknesses are discussed. The auto-guidance system being developed overcomes some of the limitations of state-of-the-art prototype æcommercialÆ systems. It can be retrofitted to existing remote controlled vehicles, uses minimum installed infrastructure and is flexible enough for rapid relocation to alternate routes. The navigation techniques use data fusion of two separate sets of sensors combining natural feature recognition, nodal maps and inertial navigation techniques. Collision detection is incorporated and people and other traffic are excluded from the tramming area. This paper describes the work being done by the group with regard to auto-tramming and also outlines the future goals.

Jan 1, 1998

By Q Zhou, Y Ma, J Zhu, R L. Frost, P Yuan

A series of organoclays with different surfactant arrangements were prepared by ion exchange. The resulting organoclays were investigated using a combination of characterisation techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric measurement (TG) and N2 adsorption-desorption. In the present study, the pores within the organoclays were discussed on the basis of the micro- structural parameters, including BET-N2 surface area, pore volume, pore size, surfactant loading and distribution. The results show that both BET-N2 surface area and pore volume decrease from low to high packing density of the surfactant as the average pore size increases. Two basic organoclay models were proposed for hexadecyltrimethyl- ammonium bromide (HDTMAB) modified montmorillonites: 1. the surfactant mainly occupied the clay interlayer, and2. both the clay interlayer space and external surface were modified by surfactant. This study demonstrates that the pore structure of the resulting organoclays has a significant influence on the sorption efficiency and mechanism of p-nitrophenol onto the organoclays.

Jan 1, 2008

Dewatering tailing slurries by mechanical means is often not possible and gravity and solar driven processes must be used. It has been shown previously that better use of gravity is achieved when the tailing is drained as it settles. Not only are more compact sediments obtained but also the dewatering is faster. From the results of laboratory and field tests reported here, equations were established which describe the evaporation and drainage components of the dewatering. These equations were used to calculate the effects of ponding depth, solids content of the tailing and clim- atic conditions on the time required to dewater the tailing. Since the calculations can be made with and without the drainage component, the advantages to be gained with drainage can be determined. The tailing used in the work was a clay slime from a sand washing operation. However, it is anticipated that this approach will be applicable to other similar tailing.

Jan 1, 1978

Geological models for the exploration and evaluation of epithermal Au and porphyry Cu-Au deposits rely upon a classification of different deposit styles and an understanding of the evolutionary processes of deposit formation. These models guide the interpretation of subsurface deposit anatomy in order to target drill testing and assist the explorationist to focus on the more prospective projects. It is important for the explorationist to distinguish between different styles of magmatic arc Au deposits as each style displays distinctive characteristics with exploration implications. Magmatic arc Au deposits are distinguished as porphyry Cu-Au formed at depths of 1 - 2 km at the apophysis to larger, buried, magmatic sources which are also the ultimate metal sources for the varying styles of shallower level epithermal Au deposits. Low sulfidation epithermal Au deposits characteristically develop from dilute circulating meteoric waters and are distinguished as the group with a closer relationship to intrusive source rocks, and slightly higher sulfide contents (still generally

Jan 1, 2004

By Ellis WK, Greenwood-Smith R

A nuclear technique for the analysis of copper in bulk materials has been developed and successfully field tested at Mount Isa Mines Limited. The technique utilises the gamma-ray resonance scattering process. A bulk analyser based on this technique gives a rapid and accurate measurement of the percentage by weight of copper or nickel aver- aged over a large mass of sample, typically 20 kg. The only sample preparation required for accurate analysis is crushing to -2.5 cm. At Mount Isa over 100 mineral samples covering a wide range of rock types and copper contents were analysed. Bulk analyser assays and chemical laboratory assays agreed closely for underground pillar-extraction and geolog- ical chip samples, conveyor belt samples, and finely ground samples from the ore concentrator. For the concentrator samples, the root mean square deviation between bulk analyser and chem- ical laboratory assays was 0.06 wt.% copper. The chemical assay errors for these samples were about 0.06 wt.%

Jan 1, 1975

By Hall S. F, Quast K. B Newell R, Ketteridge I. B

For the past six years research funded by the State Energy Research Advisory Commit- tee of South Australia has been conducted at the South Australian Institute of Technology, School of Mining and Metallurgy on South Australian lignites. A major part of this work has been a study of the potential bene- fication of Bowmans lignite using hydrometal- lurgical techniques. The Bowmans lignite de- posit is the largest of its type in South Australia and is a major energy reserve for the state. The utilization potential of this deposit is reduced by its very high insitu NaCl content which presents serious problems for any process. Previous research conducted by Readett and co-workers (1984a & b) has shown that NaCl is amenable to extraction using simple batch water leaching operations. This leaching has been successfully described using a two stage diffusion model derived from first principles based on a simple diaphragm cell.

Jan 1, 1987

Autocompression and virgin rock tempera ture have a marked influence on the ventilation of the lower levels at North Broken Hill Limited N.S.W. To maintain comfortable working temp- eratures without penalty to working hours, increase in airflow or the cooling of the work area is necessary. The use of refrigerated air cooling is discussed. Ventilation of underground mining opera tions at North Broken Hill Limited is accomplished by downcasting air through No.3 shaft, the main operating shaft, 1581 m deep, with additional air through No.1 shaft (542 m) 2 and No.2 shaft (978 m), both no longer opera- tional shafts. Air is upcasted through No.3 ventilation shaft which is 4.9 m diameter and concrete lined, from the No.28 level (1140 m) to the surface. On the surface level of this shaft is a horizontally mounted Richardson 4800 mm diameter single stage axial flow fan with adjustable pitch rotor blades.

Jan 1, 1977

By R Linares

The efficient operation of any modern metallurgical facility depends on the accurate measurement and estimation of flow rates, inventories, and composition of their intermediate and final products. All of this information is subject to both statistical errors and gross errors, which can lead to poor estimation of efficiency, yields and specific energy consumption. The detection and the elimination of these errors require not only plant data, but also product transactions and the operational events. Once the gross errors have been eliminated, it is possible to estimate validated performance indicators, such as grade recovery or yields. This paper describes the methodology to implement a unification and gross error detection system using the available infrastructure of both information and data reconciliation system. It covers the different infrastructure layers, from the data collection layer to the data validation and reconciliation layer. In addition, the impact of these methodologies on the decision-making process is presented.

Jan 1, 2005

By Fengyan D

Removing the interference of latter events, the data of geophysical (such as gravity and aeromagnetic) anomalies may indicate whether the mobile belt exist and whether the adjacent terrains of the mobile belt originally belong to one single unit. The petrotectonic assemblage can provide informations about the tectonic setting where it was generated from. The structural style can exhibit the kinetic and kinematic processes. The form of ancient isogeotherm may reflect the ancient geothermal regime which is related to the tectonic mechanism. In general, the early Precambrian terrains suffered polymetamorphism and multiple structural deformation. The researches must be carried out for the distribution of paleogeotharm and m.tamo'phic facies and zones on the basis of recovering the early structural style with structural analysis method; then a relatively correct conclusion may be geined on the ancient geothermal regime. This method can be known as "Ancient Thermotectonic Analysis". Through the sythetical research, a real knowlege about the tectonic setting of early Precambrian mobile belt can be obtained.

Jan 1, 1990