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By B Clemen, D Gordon, F Cesnik, P Griffin

In March 2002 Newcrest Mining Ltd commissioned a 4 Mtpa gold-copper concentrator at its Cadia Valley Operations in New South Wales. This paper presents the design and construction considerations, commissioning and ramp up issues related to start up of the concentrator as well as current performance and future expansion plans. Commissioning of the plant was the culmination of six years of project planning, from discovery of the resource during the Cadia Hill drill out campaign in November 1996 to project implementation and plant operation. Current resource estimates stand at around 50 Mt with an average grade of 2.4 g/t gold and 0.8 per cent copper. At current processing rates the project life is expected to exceed ten years. The processing plant comprises a 9.75 m (32 ft) diameter Fully Autogenous (AG) mill, a single 6.7 m (22 ft) diameter ball mill, pebble crushers, gravity gold recovery circuit and flotation plant. Upgrades to the existing infrastructure and manning requirements at Cadia will be discussed as well as the resultant impacts on operating costs for the operation. The processing plant was expected to deliver 290 000 ounces of gold and 30 000 tonnes of copper in concentrate in its first full year of operation and progress against that goal will be presented.

Jan 1, 2003

By G. L. Mowrey, S. D. Maksimovic

An important element of the U.S. Bureau of Mines (USBM) mining research program is the development and evaluation of reliable coal interface detection (CID) systems. Commercially available CID sensors based on natural gamma radiation (NGR) are only applicable if the immediate roof is composed of shaley material. The USBM has made numerous underground and laboratory measurements using several NGR systems approved for installation on mining machines by the Mine Safety and Health Administration. In addition, two small handheld NGR instruments were used to make comparative measurements. Underground NGR measurements in 10 different coal seams, potassium-uranium-thorium radiometric analyses on samples from 16 seams, and chemical analyses of coal and rock for correlation with NGR counts were made. Laboratory test results on the effect of air gap and sample thickness, size, and weight on the NGR measurements, as well as general results of the various NGR systems, are discussed.

Jan 1, 1995

By Dong-kil Lee

Field tests have been conducted to investigate the characteristics of flow and physical chemistry of acid mine drainage(AMD) in the Hwangji-Yuchang settling pond in south Korea. pH and ferrous concentration of AMD flowed in the settling pond is 6.79 and 25.5 mg/l, respectively. As a results, we found that the ferrous oxidation reacted strongly around the inlet of the pond and the distributions of physicochemical properties is depended on flow characteristics and ferrous oxidation rate of AMD.

May 1, 2011

By D Reid, J Black

The adverse health impacts from diesel particulate matter (DPM) exposure are a well-known global concern. The building evidence has triggered underground mining operations to review existing atmospheric conditions and assess the scale of the challenge faced. South32’s Cannington Mine (Cannington) evaluated the ability to provide a healthy atmosphere from a whole mine approach, taking into account existing preventative controls including: maintenance strategies, fuel quality, mining operations, ventilation provisions, monitoring protocols and effective education and training programs.During the evaluation process, Cannington gave due recognition to the advice and guidance provided in the Queensland Guidance Note 21 (QGN21), the Guidelines of New South Wales’ MDG29 and Mining Industry Advisory Committee (MIAC) of Western Australia. Each of these documents advises a dilution rate of >0.06 m3/s/kW is best for reduction of DPM exposure in underground mines.Achieving the prescribed mine ventilation rate typically results in the need to directly invest significant capital into increasing ventilation infrastructure in order to further dilute contaminants. In today’s economic market of volatile metal prices and increasing pressures to meet regulatory requirements, it can become challenging for established metalliferous operations to create a balance between optimisation of current ventilation infrastructure and capital outlay.In order to obtain and correctly justify the requirements for capital investiture Cannington conducted a ventilation operational analysis for the life-of-operation, identifying the existing air volume envelope was adequate for current and future production rates by optimising existing primary ventilation infrastructure through the implementation of a modified ventilation on demand (VoD) and air conservation system.This process achieved sustainable operating and capital cost reductions without compromising delivery of adequate ventilation to work areas. The process also recognised that engaging mine workers’ ownership of their work areas is crucial to maintaining a technically efficient and operationally robust ventilation system.This paper will concentrate on Cannington’s existing preventative controls, their implementation and their management for the prevention of increased DPM exposure; reducing the risk of both short and long-term health impacts to ‘as low as reasonably achievable’ (ALARA).CITATION:Black, J and Reid, D, 2017. Delivering a healthy atmosphere underground in a cost-conscious environment, in Proceedings Australian Mine Vent Conference 2017, pp 159–168 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Jesús Ylazaca

El presente trabajo describe el método de control de calidad del mineral o el denominado "Ore control", realizado en la unidad minera Yauli, cuya finalidad es maximizar el valor del mineral minado para lograr una mayor rentabilidad. En este sentido, el "ore control" es la gestión que optimiza las diferentes etapas de la exploración, explotación y concentración del mineral para lograr una buena calidad de producto (concentrados), a fin de satisfacer las necesidades del cliente. Los controles involucran a la Gerencia y el total de supervisores y trabajadores de operaciones, quienes deben ser proactivos ejecutando acciones preventivas más que correctivas.

Sep 12, 2005

By Yiming Sun

The 5-mile long Bay Tunnel is a major water supply facility to be constructed under the San Francisco Bay and adjacent marshlands between the San Andreas Fault to the west and the Hayward Fault to the east. The tunnel will have a two-pass lining system consisting of a watertight precast concrete segmental initial lining and a welded steel pipe final lining. Considering the Bay Tunnel?s location between two major active faults, the design earthquake produces a significant peak ground acceleration estimated at approximately 0.6g. To develop a design that can achieve the seismic performance objectives, full dynamic seismic analyses were performed using site-specific earthquake time histories. The analyses considered soil-structure interaction and an evaluation of the transverse and longitudinal effects of the design earthquake. This paper describes the seismic analyses and the design measures recommended to minimize potential adverse effects of the design earthquake on the tunnel final lining.

Jan 1, 2008

The problems of using comparatively simple x-ray diffraction equipment for quantitative analysis are examined. Internal standard and direct calibration procedures based upon the measurement of integrated diffraction energy (diffractometer peak area) have been developed for the determination of quartz in Broken Hill dusts. By these methods an accuracy of ± 10 per cent of the true value can be obtained and this can be improved to ±2 1/2 per cent by statistical methods if necessary.Rapid analysis for the components quartz, muscovite, rhodonite, galena, fluorite, sphalerite, calcite, and garnet has been developed by adaptation of direct calibration procedures and use of maximum diffraction energies (diffractometer peak height). Until more is know!) about the pathological effects of multi-component dusts of the Broken Hill type it seems undesirable to fix theIr allowable concentrations in terms of the quartz content.

Jan 1, 1968

Conventional hand drawn isopach maps of the cover of the Bulli Seam are too eomplex for use in the delineation of large domains of similar cover. Isopach maps prepared from trend surfaces fitted to the cover data are much simpler in form and so provide a convenient method of delineating broad domains of similar cover.

Jan 1, 1968

By Corry Goumans, Dwayne Wallace

"On July 1, 1997, a rockslide occurred on the I-40 in Hayward County, North Carolina that completelyblocked all lanes and disrupted traffic flow in the region. Remedial measures were undertakenimmediately in order to open traffic, however on-going geotechnical investigation revealed stabilityconcerns that necessitated closing the highway to ensure public safety. Access to the top of the slope was available only from the bottom of the slide on the Interstate I-40. Excavation and trim blasting started from the top and along the west slope of the failure, however, additional geotechnical evaluation indicated that slope stability remedial measures were required to support the western rock slope mass."

Jan 1, 1999

By Pfeifer H. C, Nicacio P. A D

Sinter has been used as part of the metallic charge in large-scale blast furnaces for many years with the well-known benefits in terms of productivity and fuel consumption. However, because of the high investment in a conventional sinter plant, small blast furnaces and the associated integrated mini steel plants have not taken the advantages of using sinter. Recently KTS Korf Tecnologia Siderurgica, a division of Mannesmann Demag Ltda in Brazil, has developed a mini sinter plant for which the investment is compatible with small blast furnaces. Consequently, it is of great interest to evaluate the economical impact of using sinter in such small-scale integrated steel plants. In order to compare two alternatives, ie 100 per cent ore and 70 per cent sinter in the blast furnace burden, mass and heat balances for the entire operation from sinter plant through the blast furnace and EOF-based melting shop, were performed to evaluate the final production cost of the liquid steel. It was found that, depending on the sinter feed price, substantial savings can be obtained with the use of sinter.

Jan 1, 1999

By J. A. Meech, G. R. Baiden

"A dynamic simulation of a mine-mill complex has been conducted using networked microcomputers (IBM PC/AT and IBM PC/XT). These models allow simultaneous operation of an open pit using shovels and trucks, a primary crusher, and a secondary crushing plant. Each process transmits information via the network, linking all operations together. The effects of blasting, ore quality, equipment utilization and configuration on productivity can be studied either interactively or from a report listing at the end of each shift. Programs are menu driven leading the user through the decisions required in day to day operations. The mine-mill simulator is currently being used as a teaching tool at Queen's University to provide senior mining and mineral processing engineering students with an experience and appreciation for the operating problems across the mine-mill interface. The need for coordination and close communication between the mine and mill can be aptly demonstrated using these models. The simulator could be used to contribute to the training of operating personnel in a real mining operation. INTRODUCTIONThis paper describes a computer simulator that is capable of showing the interactions and operating strategies between a mine and a secondary crushing plant. The simulator uses two models developed at Queen's University; one for open pit mining and the second for secondary crushing. PITSIM is a dynamic shovel/truck haulage model origin2lly developed by P.D.D. Chick (1) and K.G. Fytas (2) to solve shovel/truck scheduling problems. CRUSHSOFT is a dynamic secondary crushing plant model developed by R.J. Tucker (3) and C.A. Harris (4) to study alternative operating and control strategies in a crushing plant."

Jan 1, 1987

Typically, large volumes of data are collected during geotechnical investigations for mining projects but rarely is this done in a comprehensive manner that enables all aspects of the geotechnical environment to be evaluated. A geotechnical core logging process has been developed to record mechanical and structural properties of the rock mass. The method enables data for a wide range of rock properties and geotechnically significant major structures to be collected including rock strength, joint surface condition, fracture frequency and fracture orientation. The logging method is unique in that sufficient data is collected to enable the independent determination of all the major rock mass classification systems including rock mass rating (RMR), (Bieniawski 1976, 1989; Laubscher, 1990) Norwegian Geotechnical Institute (NGI) tunnelling quality index (Q) (Barton, Lien and Lunde, 1974) and geological strength index (GSI) (Hoek, Kaiser and Bawden, 1995). The logging system has been specifically developed to allow better and more precise appreciation of rock mass and structural conditions across the project area thereby optimising the use and application of the available geotechnical data and improving confidence in the outcomes of geotechnical investigations. This paper describes the core logging process with case examples showing how the logged data can be used for underground and open pit mine design.

Nov 25, 2010

By Marc Ruest, Lewis Martin

A new instrumented cable bolt has been developed by the National Institute for Occupational Safety and Health at the Spokane Research Laboratory in Spokane, WA. Although various instruments are available to measure load distribution and magnitude along a grouted cable, this instrument is innovative in that it uses strain gauges internal to the cable as load-measuring sensors. The instrument has been successfully tested in the field at FMC’s Granger Mine, Meikle Mine, and Getchell Mine. A “split-pipe” laboratory pull test was performed on each of three cable bolts instrumented with the new device. Each test consisted of grouting a 1.83-m-long cable in two 0.91-m-long sections of schedule 80 pipe. A numerical analysis was then performed in which laboratory boundary conditions were simulated and model properties derived from textbook guidelines. The loads calculated by the model were then compared to the measured loads.

An extensive series of tests was carried out on a ball mill-rake classifier circuit in the New Broken Hill Consolidated Ltd. concentrator. The data were used to develop a mathematical model of the operation of a rake classifier and this model has been used in the simulation of the performance of a ball mill-rake classifier circuit on a digital computer. As a result of this simulation it has been possible to develop a technique for the optimization and control of a circuit which includes these units.

Jan 1, 1967

By David W. H. Ellis

This presentation will discuss over 2 dozen past, present and future oils sands projects in Alberta. The very early projects as well as the most recent along with the ones that never got off the ground and the ones in production are all included. For each, the following will be given (where known): owners, location, type (mining/SAGD/refinery), production, capital budget, spent to date, status. Some overall impacts will be discussed.

May 1, 2004

Pressure for Better Safety Practices ? Increase Government Regulation ? Safety practices evolve from: ? Increased efficiency and performance ? More knowledgeable workforce ? Focus on decreasing risk to shareholder value In Order to achieve this ? Focus Points: ? Skill Development ? Best practices ? Situation-based decision making ? Enablers: ? Adoption of new technologies ? Transformed miner education ? Delivering on-demand information to the point of work Results: Miners empowered to improve mine safety

Aug 1, 2013

By P M. Outhwaite

Everyone present today is especially aware of the need for minerals in this society of ours. The words 'especially aware' were deliberately chosen because this is a meeting of the NZ Branch of The Australasian Institute of Mining and Metallurgy not a dilettante group such as some of our critics. Members of the Australasian Institute of Mining and Metallurgy knew that our great farming industry, our shelter, our transport and our energy supply, are largely dependent on a flow of minerals into this country despite the presence of large coal and natural gas reserves. Flow in was said because New Zealand imports most of its mineral requirements with all the consequential strategic and economic disadvantages. If the above statements are accepted by this gathering it would be a premise fairly stated that New Zealand has a great need to discover and develop minerals.

Jan 1, 1976

By F. E. du Plessis

"The distinction between data suitable for process control and data subject to aliasing only becomes quantifiable with the availability of rapid real-time measurements. Expecting the dynamics of flotation to vary for different ore types, process flows and equipment types; a study was conducted to compare the dynamics of different flotation processes. The results shed light on the critical sampling intervals required for process control which in turn allows process stabilization and optimization. The technology used for the in-line measurements is based on diffuse reflective spectroscopy and has been introduced into the mineral processing industry over the past ten years. It has been widely implemented in the sulphide flotation industry in South Africa for the real-time measurement of grade.BACKGROUND AND OBJECTIVE A study was conducted by Du Plessis and Keet (2010) to quantify the minimum sample frequency required for grade and/or impurity control. The study was based on chromite data collected at 15 second intervals from the concentrate line of a flash float cell in the Platinum industry. The data captured the natural process variation of the entrained chromite through water recovery due to changes in feed parameters and flotation performance. It was found that the minimum rate of sampling required from the studied flash float concentrate was 2 minutes. This sampling interval time accounted for 90% of the variance in the process data. It was further found that a sampling interval time of longer than 4 minutes produced data with no significant correlation to reality. The dynamics of the flotation process has been misjudged in the past but can be quantified with the availability of real-time grade measurement based on diffuse reflective spectroscopy. The objective of the study was to compare the dynamics of different sulphide flotation processes through the comparison of maximum sampling interval times required to combat aliasing. All data were collected from single stream analyzers that are currently installed at mineral concentrators. The technology used is based on diffuse reflective spectroscopy."

Jan 1, 2012

At Great Boulder Gold Mines Ltd. a number of attempts were made to remove water soluble copper and iron salts from calcined pyritic concentrates but variou~ problems arose and the methods were abandoned.A method of rapid washing has been developed and although some problems still exist a workable process was established which resulted in substantial savings of reagents used for the cyanidation of calcine.INTRODUCTIONIn the Great Boulder flowsheet crude ore is ground in cyanide solution, then thickened, agitated and subjected to two stage filtering. Secondary filter discharge is pulped with flotation circuit water, gassed with sulphur dioxide to precipitate soluble gold and activate pyrite, and after the addition of copper sulphate and xanthate, the pyrite and tellurides are recovered by flotation. Flotation tailings are thickened and pumped to the disposal area and concentrates are calcined in Edwards roasters. Calcine is washed to remove water soluble copper and iron salts and the washings pumped to the flotation section where the copper is used as an activator. The washed calcine is cyanided and returned to the crude ore circuit via the thickeners. Solution for precipitation in the Merrill Crowe is drawn from the crude ore thickeners.Prior to the introduction of calcine washing the calcine contained 7 lb/ton copper of which approximately 60 per cent was water soluble. It also contained approximately 90 lb/tol'l of water soluble iron salts. Both the copper and...

Jan 1, 1964

By John J. Vieaux

Allowable loads on Dynamically-Cast-In-Place Piles (the Franki type) can be correlated with N values from the Standard Penetration Test. Using a constant developed by Nordlund, a conservative value for load-carrying capability of a DCIP pile is developed. The DCIP pile and method of installation is briefly described.

Jan 1, 1984