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By J A. Cowburn

The high intensity zone within the Jameson Cell is the downcomer. It is largely external and separated from the flotation tank. This, together with operation of the downcomer under vacuum, rather than at elevated pressure and the absence of moving parts, allows ready access to the high intensity zone for measurement and analysis. Experimentation was conducted allowing measurements of recovery for residence times of between 20 milliseconds and ten seconds within the downcomer of a Jameson Cell. The affect of aeration rate on the recovery of different particle sizes was also studied.

Jan 1, 2005

By Nelson G

The construction and placement of tunnels by means of jacking is continually advancing. This paper presents an outline of the construction of a major highway tunnel placed by a combination of mining and progressive placement by hydraulic jacking of precast units. Features of the project were the relatively shallow ground cover between rail and road routes over the tunnelling and jacking operations and also the weight of tunnel sections to be moved into position.

Jan 1, 1993

The winning and upgrading of mineral raw materials necessarily includes size reduction, which serves the liberation and production of marketable products from highly valuable and bulk materials. For crushing, the following factors can be duly accounted for depending on material type and the selection of the suitable machine: ò producing a particular size distribution, ò producing a particular grain shape, ò selective comminution, ò gentle comminution, and ò producing a size range required by a specific process and/or for a specific product.

Jan 1, 1993

Roadheader tunnelling machines have been used in Australia by both mining companies and contractors involved in the mining and con- struction industries since the early 1970's. They have both advantages and limitations, and this paper discusses machine excavation from the point of view of a contractor who has both reaped the benefits and suffered the conse- quences of using roadheaders. The paper also includes brief descriptions of three projects tackled by roadheader, all the projects being Declines.

Jan 1, 1987

The advancements achieved in rapid tunnelling in the 60's and 70's have been notable. It is unfortunate that shaft sinking has not enjoyed equivalent advances and there are many good reasons why this is so. Technical and commercial considerations have held back development and continue to do so despite the increasing urgency in the search for minerals and energy. By the careful selection of an appropri- ate project and the application of specialist engineering the Bdard took advantage of a unique opportunity to apply a mechanised shaft borer in field conditions.

Jan 1, 1981

The Mesozoic intrusive rocks in southeastern coastal China can be divided into three intrusive suites, and they can be brought into corresponding with four cycles of volcanic activity. This paper describes their time-space relation with volcanic rocks, and their geochemical characteristics. Data from the Mesozoic volcanic-intrusive. complex rocks in Eastern Zheijiang, Eastern Fujiang and Eastern Guangdong show distinct regional differences, both within and tectonomagmatic activity regions. The southeastern coast of China involves four tectonomagmatic activity regions. They have many differences on the nature of magma source regions, activity patterns of magma, time-space distribution, petrography and petrographic facies association of volcanic and intrusive rock and mineralization.

Jan 1, 1990

By G D RICHMOND, Campbell J. J

Aberfoyle Limited has developed the Hellyer complex base metal sulphide deposit located in North West Tasmania. As part of exploration and feasibility study, the ore was extensively tested, including trial milling, and was found to be very fine grained and to have poor flotation selectivity. Substantial innovation was required to produce saleable concentrates at acceptable recoveries and costs. Efforts were made to reduce operating costs, to improve metallurgical performance and to improve work organisation. These efforts were pursued both in design and in subsequent plant operation. This work has resulted in a very competitive operation with production costs in the lowest quartile of the industry. Examples of the measures taken are presented and the results are evidenced by improved plant performance since commissioning.

Jan 1, 1992

By R Grogan

Nautilus Minerals Inc is a sea floor resource exploration and development company focused on developing the Solwara 1 Project, a copper-gold sea floor massive sulfide deposit in the territorial waters of Papua New Guinea, for which it holds a mining lease and associated environment permit.Economies depend upon four key types of capital: built, natural, financial and human. Natural capital consists of the ‘minerals, energy, plants, animals, ecosystems (climatic processes, nutrient cycles and other natural structures and systems) found on Earth that provide a flow of natural goods and services’ (Daly and Farley, 2004). Many ecosystem goods such as fish, fruit and water are already valued and sold in markets; however, some ecosystem services are not amenable to markets and have remained unvalued in traditional accounting methods, even though they provide significant value (such as flood protection, climate stability etc; Batker and Schmidt, 2015).There are now economic methods available to quantify and value natural capital and many non-market ecosystem services. When valued in dollars, these services can be incorporated into a number of economic tools, including benefit-cost analysis, accounting, environmental impact statements, asset management plans and rate of return on investment calculations. Their inclusion ultimately strengthens decision-making. When natural capital assets and ecosystem services are not considered in economic analysis, they are effectively valued at zero. This omission can lead to poor decisions, inefficient capital investments, higher incurred costs and losses due to unexpected events (Batker and Schmidt, 2015).In 2015 Earth Economics was commissioned by Nautilus Minerals Inc to conduct an independent, objective environmental and social benchmarking analysis of the proposed deep seabed Solwara 1 mine with terrestrial copper mines (referred to as ‘the report’). The report represents the first ever natural capital accounting and ecosystem goods and services framework for seabed mining.The report compares the proposed Solwara 1 mine with three terrestrial mines: Bingham Canyon (Utah, USA), Prominent Hill (South Australia, Australia), and Intag (a proposed mine in Intag Province, Ecuador), and provides a natural capital accounting assessment for all four operations.CITATION:Grogan, R, 2016. Natural capital accounting – a sea floor mining application, in Proceedings Life-of-Mine 2016 Conference, pp 2–4 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By S D. Dessureault

In one of North AmericaÆs largest mines, which contains more than six active coal-producing faces, mine controllers must meet the complex challenge of adhering to the mine plan while also ensuring customer quality. Fleet management systems (FMS) provide many different avenues to control production flows, from the faces to the various pit crushers. Nonetheless, mine controllers must balance a variety of factors such as unplanned downs, differing customer demands, their own daily key performance indicators (KPIs) related to equipment utilisation, among others. Deviating from the short-term mine plan is the most common means of balancing the other factors, since adherence to the plan is traditionally only measured during the weekly variance meeting with engineering staff. However, such deviation may be one of the most costly responses, as long-term scheduling issues may arise such as multi-face dead-heading or insufficient stripping. This paper focuses on the development of a system for real-time adherence to mine plan within a control room environment. This system is part of a larger blending-focused, multi-million dollar project with elements of a centralised remote control room, developed at the University of ArizonaÆs Mining Information Systems and Operations Management (MISOM) Mine Control Center (MC2). The mine plan (MPL) component of the overall blending system integrates both historical and real-time FMS data with mine plan requirements directly sourced from original systems (no additional input required). The measures, displayed largely as graphs, have tools to help controllers manage the production to facilitate adherence to the plan. Some measures are designed to motivate crews to perform by inciting competition between crews, softened through a study of the controller culture. The MPL component was deployed at the mine, and the before and after deployment adherence was measured. This paper discusses the technical development of the new tool, its deployment, and an ethnography (study of culture) to understand controller motivation.

Sep 26, 2011

By H Zahiri

Utilisation of the InSAR technique for monitoring of subsidence in mining areas, employing open pit and underground mining methods, has large potential due to sensitivity and safety issues associated with usage of the classical surveying techniques. InSAR can also be very competitive concerning the cost of provided results. However, there are a few issues that may significantly limit InSAR applicability for subsidence monitoring in mining areas. The altered terrain topography, involving steep slopes and deep pits, may lead to the layover of radar signal for specific satellite and pit geometry. Also, the highly dynamic character of subsidence induced by mining, especially using mass mining methods, may lead to issues such as apparent heave and ambiguous results. In this paper the authors analyse the above-mentioned issues and demonstrate how InSAR technology was applied, as a supporting system, to monitor large scale and highly dynamic subsidence for a real case study in Western Australia.

Jan 1, 2008

By M Kongas, K Saloheimo

Concentrating lower and more variable grade ore resources to meet acceptable concentrate quality criteria requires removal of significant amount of gangue minerals. Monitoring plant feed mineralogy and concentrate by on-stream analysis has significant economic benefits in concentrate quality and recovery optimisation. There is a need to develop a sensitive slurry on-line analyser for silica, aluminium, magnesium and other light elements.On-line XRF elemental analysis technology, which is a routine practice in base metal concentrators is not able to measure lighter elements than calcium from slurry. Too much of the X-ray fluorescence signal from lighter elements is absorbed by water. The limitations in the direct measurement of silica and other light elements have restricted its use in some applications. Some light element slurry analysers have been developed based on prompt gamma neutron activation (PGNAA) method but they have not performed up to the expectations. This paper describes a new on-line elemental slurry analyser and the results of on-line laboratory tests.CITATION:Kongas, M and Saloheimo, K, 2013. Online light element slurry analysis, in Proceedings MetPlant 2013 , pp 93-101 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Weber D, Knox PR

The criteria developed for the Argyle Diamond Mine process plant control system are reviewed. The control system installed is described along with a discussion of the method of implementation adopted. The control system was extensively tested prior to instal- lation at site. This approach led to signi- ficant time savings during plant commissioning and facilitated rapid escalation of plant production. The control system has performed satisfactorily with a high level of operator acceptance and basically satisfies the criteria Developed.

Jan 1, 1986

Agglomeration pre-treatment is a new process now being used here and overseas whereby problems arising with the heap leaching of gold and silver from materials containing critical amounts of fines or clay can be simply and cheaply overcome. The technique involves mixing the material with a suitable binder, commonly Portland Cement, and tumbling the moistened material to agglomerate the fines. These agglomerates are placed on the leach pad and cured prior to leaching. Test results, plant and operating cost data are presented. INTRODUCTION Heap leaching is a low capital and operating cost alternative to conven tional processing techniques for gold and silver extraction. A number of commercial-scale operations have recently started in the United States and the method is being considered for further deposits there and elsewhere.

Jan 1, 1982

By Brosnan J. G

Simcoa Operations is the only silicon smelter in the region and since the plant was commissioned in late-1989, has progressed from supplying silicon metal to the secondary aluminium market to the current position of supplying in excess of 90 per cent of its production to the high quality chemical and primary aluminium markets. This position has been achieved through the unique advantage which Simcoa has developed within the industry, namely raw materials, people and Simcoa's ability to adopt and use modern technology. A quality culture was instilled into the workforce prior to commissioning which ultimately led to AS3902 qualification in 1992. Simcoa has continued its quality drive through the formation of 'Simcoa's Quality Leadership Process' which is planned to make Simcoa the best silicon producer in the world.

Jan 1, 1995

Analysis of different environmental scenarios and to represent, spatially, of impacted areas is possible by the use of geoprocessing techniques, specifically Systems of Geographical Information (SIG). Through these systems it is possible to create dynamic mathematical models, constituting of a georeferenced digital database and employing the integrated data originated from several sources. In this context, the general goal of this paper is to apply this tool in an environmental analysis of a specific karstic area impacted by mining activities. In order to preserve a limestone site, internationally recognised by its archaeological features, including caverns, lakes and evidences of prehistoric ages, the Brazilian government has created the Lagoa Santa Environment Protection Area. This place is located in the proximity of the Belo Horizonte international airport. In the past two decades exploitations of dimension stones have increased in this area. These exploitations have been done without a mine plan promoting several environmental impacts. The objective of this paper is to analyse these activities using SIG as a basic tool to locate the main mining related impacts and propose mitigation measures including waste and tailings disposal and reshaping of the landscape and introducing a drainage system for the considered zone.

Dec 6, 2010

Inefficient conveyors suffer carryback, leading to the build-up of materials on idlers, and other expensive components. They spill and leak material at loading zones and transfer points, causing accumulations that can damage the belt, wear moving components, and increase both cleanup labor and maintenance expense. They wander or mistrack, spilling material and en- dangering personnel and conveyor components, including the belt itself. And through these inefficiencies, they multiply an operation's hidden costs-the dollars lost because of missed production, of increased downtime, of the expense for the replacement of prematurely worn or damaged equipment. In this paper, the author will examine the importance of belt conveyors to mines and process plants He will trace the state-of-the-art in systems for cleaning belts, and controlling the release of fugitive material from conveyor transfer points, by exploring the roots of the problems, and demonstrating solutions that have been proven to be effective. Included in these systems to improve material handling are transfer point stabilization and sealing systems, dual belt cleaning systems, and belt training idlers.

Jan 1, 1991

This paper discusses equipment replacement strategies and specifically addresses the upgrading of technologically superseded equipment. The process of equipment replacement evaluations is reviewed, and areas have been highlighted where currently accepted practice results in a bias towards retaining existing equipment longer than otherwise justified. The Discounted Average Cost Method is described and the advantages of the technique for this style of decision making discussed. Several key issues influencing the replacement evaluation are also presented together with examples from recent consulting work.

Jan 1, 1992

By Dendyuk TV

The possible use of combined (flotation/magnetic separation and magnetic separation/flotation) technologies involving the new flotation reagent systems for upgrading the iron ore concentrates, low grade manganese products and beneficiation of graphite-bearing dusts from integrated iron-and-steel works has been shown. It has been found that the absence of magnetic flocculation phenomenon worsens the reverse cationic flotation of oxidised iron ore concentrates and direct flotation of low-grade manganese products which require the use of modifiers possessing the flocculating properties. The synergetic mixtures of polymers have been proposed to be used as modifiers, ie polyacrylamide (PAA) with carboxymethyl cellulose (CMC) and polyacrylamide with industrial lignosulphonates (LST)

Jan 1, 1993

By R H. Eric

Surface wave formation induced by a high-strength submerged jet in a bottom blown metallurgical vessels has been studied experimentally by using one-seventh water model of CLU (Creusot-Loire Uddeholm) reactor with two different tuyere configurations. Experimental results have been discussed in terms of the wave period, wave frequency and wave amplitude with respect to air injection rate and tuyere configuration at a 0.23 m bath height. The results from high speed photography observations displayed the formation of rotating surface waves which circulates within the water model. It was found that the frequency and the amplitude increased with gas injection rate. The wave period for off-centre nozzle orientation was found to be lower than those of the centre configuration. The experimental results also showed that the frequency of a rotating wave increases when the tuyere orientation becomes off-centred . The predicted amplitudes were in very good agreement with the experimental values over a range of gas flowrates between 0.00599m 3/s to 0.01081 m 3/s.

Jan 1, 2000

By Moort van J C

A new low-intensity magnetic separator which operates by spinning particles in a continuously rotating magnetic field is able to reduce particle entrapment of non-magnetics to an almost insignificant level. In such separators the removal of ma

Jan 1, 1997