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In the Illawarra District of New South Wales, Mines were traditionally developed from the seabord. The advantages were close access to the working faces and a minimal depth of cover. Travelling times to the working faces have become prohibitive in many cases due to progressive westward development of the mines. As a result, additional vent- ilation shafts were sunk to service existing mines and new mines were established west of the Illawarra escarpment. Mining operations west of the escarpment are now being conducted at an increasing depth of cover and can be effected by gas related problems such as high seam gas emission rates and gas outbursts.

Jan 1, 1983

By Welch B. J

Results obtained from linear sweep voltammetry at a graphite anode in cryolite-alumina melts are presented, together with those obtained from a chronopotentiometric investigation of the influence of dissolved metal. The results, consistent with both production information and other fundamental studies, showed that the following two reactions occur at the anode.Equation 1Al (dissolved) ? Al3+ + 3eThe latter accounted for some of the loss in currentefficiency.The rate of the former reaction is limited by the slow desorption of the CO from the electrode surface. Mass transfer conditions, and hence cell design, influence the importance of the second reaction.

Jan 1, 1976

By J Vann, S Jackson, O Bertoli

Ordinary kriging and non-linear geostatistical estimators are now well accepted methods in mining grade control and mine resource estimation. Kriging is also a necessary step in the most commonly used methods of conditional simulation used in the mining industry. In both kriging and conditional simulation, the search volume or ækriging neighbourhoodÆ is defined by the user. The definition of this search can have a very significant impact on the outcome of the kriging estimate or the quality of the conditioning of a simulation. In particular, a neighbourhood that is too restrictive can result in serious conditional biases. The methodology for quantitatively assessing the suitability of a kriging neighbourhood involves some simple tests (which we call æQuantified Kriging Neighbourhood AnalysisÆ or QKNA) that are well established in the geostatistical literature. The authors argue that QKNA is a mandatory step in setting up any kriging estimate, including one used for conditioning a simulation. Kriging is commonly described as a æminimum variance estimatorÆ but this is only true when the neighbourhood is properly defined. Arbitrary decisions about searches are highly risky, because the kriging weights are directly related to the variogram model, data geometry and block/sample support involved in the kriging. The criteria to look at when evaluating a particular kriging neighbourhood are the following: the slope of the regression of the ætrueÆ block grade on the æestimatedÆ block grade; the weight of the mean for a simple kriging; the distribution of kriging weights themselves (including the proportion of negative weights); and the kriging variance. Outside of the technical geostatistical literature, there is little in the published domain to describe the nature of QKNA and no practical presentation of case examples. In this paper we attempt to redress this by setting out the calculations required for QKNA and defining some approaches to interpreting the results. Several practical worked mining case examples are also given. Finally some comments are made on using the results of QKNA to assist with block size selection, choice of discretisation and mineral resource classification decisions.

Jan 1, 2003

By Simes C. D

Results of experiments for dissolution of zinc by aeration of sphalerite in glass, copper, galvanised iron and stainless steel vessels of identical dimensions are reported. It was found that in a glass container dissolution of zinc reaches a maximum after 30 min aeration and then decreases whereas in the copper container dissolution remains nearly unchanged up to 30 min aeration and then increases. In the cases of galvanised iron and stainless steel containers zinc dissolution increased steadily with time up to 60 min aeration. It is suggested that the different rates of dissolution in glass and copper containers may be due to electro-chemical actions.

Jan 1, 1984

ICI Australia has been developing PC-based software to assist the blast engineer to design and monitor open pit blasts. The scope of this software differs significantly from commercially available mine design packages.The software is designed for routine use in a normal production environment. The system enables the engineer to produce practical documents which include: a drilling plan, a loading sheet, a hook-up diagram, an inventory of explosives and auxiliary items, and other data on the blast such as tonnages and powder factors.

Jan 1, 1992

By Newell R

The influence of layering on the rate of heat transfer through a packed bed consisting of particles of two different sizes and heat capacities has been determined by measuring the heat front velocity through beds of quartzite particles and iron ore pellets. The heat front velocity through the layered beds was less than that through a bed consisting of a random mixture of the par- ticles. This is due to the formation of an interface in which the smaller pellets in one layer penetrate into the layer of quartzite Below.

Jan 1, 1987

By Sorokin M. L, Komkov A. A

Flash smelting of nickel sulphide concentrate has been practiced at WMC's Kalgoorlie Nickel Smelter for 20 years. The mineralogy of the concentrate from the original mines was particularly suited to this process. However, taking a strategic view, potential new processing routes should be fully evaluated as possible replacements for the current technology. The Vanyukov process has been under development in Russia for the past 40 years and has been successfully applied on a large scale to the smelting of copper concentrates, at two locations - Norilsk and Balkhash. The potential for the application of the Vanyukov process to the smelting of nickel concentrates offers a number of processing advantages, including smaller reactor and decreased dependence on fuel oil. This paper reports on preliminary investigations into the application of the Vanyukov process to the smelting of nickel concentrates. At this stage the investigations are limited to semi-quantitative comparisons and modelling studies.

Jan 1, 1992

By Miovski P, Hooft P. V

In the majority of recently commissioned gold mines granular activated carbon is used to adsorb gold from alkaline cyanide pulps or solutions. At the same time the carbon also adsorbs many other inorganic and organic species, most of which lower the activity of the carbon. Removal of these foulants is necessary before the carbon is reactivated and recycled. Standard practice for re- storing carbon activity involves high temperature treatment in a kiln - an apparently straightforward unit operation which is not always satisfactorily carried out. This paper presents the results of some fundamental work carried out on the thermal reactivation of carbon in a laboratory rotating pot kiln. The effects of temperature and steam addition on carbon activity were examined and compared with the activity of carbons obtained from a number of commercial kilns. Carbon was also reactivated using a small-scale Rintoul Furnace in which carbon was resistively heated by the direct passage of an alternating electric current. It was established that both elevated temperatures and the addition of steam to hot carbon generally enhanced its activity although peat-based extruded carbons responded a little differently to coconut shell types. Other measurements made included the weight loss and the hardness of carbons as a function of reactivation conditions.

Jan 1, 1987

By R H. Boffey

The Osborne copper-gold deposit was discovered in North-West Queensland in 1989. Underground production activities commenced at Osborne deposit in April 1996. This paper will examine technical and operational aspects of the underground mine during its development to a 1.2 Mtpa operation . Technical aspects discussed include geology, mine design and mining methods, equipment fleet selection and capital infrastructure. Operational aspects discussed include the evolution and performance of the integrated work teams that are utilised at Osborne to perform all mining and maintenance activities.

Jan 1, 1998

The behavior of a curved wall under earth pressures for a horseshoe shaped tunnel lining is considered to be closely related to the beha vior of a vertical beam with variable flexural sti-"ness on an elastic foundation. In stress analysis an approximate method which divides the axis of the tunnel lining into small finite lengths and replaces the integrals by summation is usually adopted. this method is extremely complicated and tedious. However the variations of the moment of inertia from point to point along the wall axis can be expressed by a power function inversely .eith the distance from the ll )ottom and the analytical method can still used. The equations for the calculation of deflection, rotation, bending moment, shearing urce, and soil reaction of the curved wall are derived in nondimensional forms in this paper.

Jan 1, 1987

Choosing an Effective Dust Suppressant

Sep 13, 2010

By Toomey P. T

In many open cut coal mines, rivers and large creeks can cause planning and operating difficulties, both in the terms of the more obvious location of the current watercourse, but, and sometimes more importantly, past meandering of the watercourse. Prevent and past flow regimes may have deposited large alluvial sequences within the current mining areas. The presence of groundwater within the alluvium further complicates the planning and operating practices.A situation exists at Saraji Mine in which alluvial sediments overlie a massive sandstone sequence which in turn lies at about one metre above the coal seam. The problems encountered include high levels of groundwater ingress to the pit, highwall instability, and an unacceptably high rate of blast hole collapse (prior to charging with explosives). Other aspects of the dragline stripping operation were also affected.

Jan 1, 1992

By Russell J

A sustained drop in the grade of Mount Isa lead-zinc-silver ore occurred in mid 1980. It was decided to increase concentrator throughput from 200 000 to 240 000 tonnes/four week period to maintain budget metal production. To achieve this increase whilst maintaining acceptable grinding and flotation performance, crushing plant final product size had to be reduced from 100%-13mm to 1000-11.2mm. The goal in the crushing plant was to achieve a 20% increase in throughput with a 20% decrease in the top size of the product. This was achieved by operational changes to improve plant availability and optimisation of the existing crushing and screening equipment Performance.

Jan 1, 1978

By M Donatelli, E Grazio, A Heissenberger

The distribution of a contaminant in a bulk mass greatly influences the effectiveness of sampling procedures. Most currently used sampling guidelines for genetically modified organisms (GMO) testing have stringent distribution requirements. Specifically, all these protocols are based upon the assumption that GM material, if present, is randomly distributed. Yet, assuming randomness is risky because the applied sampling plan may not provide an accurate estimate of the content of the contaminant. Despite the general consensus that an evaluation of the possibility of non-random distribution of GM materials within lots is a pre-requisite for the definition of effective sampling protocols, no experimental data on the distribution of GMOs in kernel lots are available anywhere in the world. Additionally, to date there is no distribution-free statistical model to estimate sampling errors, thus making the theoretical definition of optimal sampling technique impossible when randomness cannot be assumed. Here we present preliminary results of the KeLDA project, which is the first study investigating the distribution of GM materials in large soybean lots imported within the European Union. The extensive variability of GM content, observable both within and among soybean lots, indicates that heterogeneity issues cannot be overlooked when defining sampling strategies for large lots of particulate material and that randomness cannot be assumed a priori. A new statistical model free from any distribution assumptions, developed in order to estimate the sampling error associated with different sampling protocols together with the risk of false-negative results, is also presented. The new model, which is applicable to any consignment of particulate material with respect to any kind of contamination, presents two novelties: first, freedom from any distribution assumption; second, the possibility of estimating the magnitude of the sampling error associated with different sampling protocols as a function of specific distributional properties.

Jan 1, 2005

The perception of the mining industry in the Australian community has changed considerably over the last four decades. This has been partly brought about by changing values and expectations of the Australian community as well as by global factors. The legal environment for the Australian mining industry has undergone significant changes. Among them, the High Court's Mabo decision which confirmed native title rights as part of the common law and environmental legal developments are dealt with particularly. It is suggested that the Australian legal environment is not necessarily the prime cause for Australian mining companies taking their investment off shore. This is a summary on how native title impacts on land tenements and some of the major issues that emerged since the `Mabo decision' and the Native Title Act 1993 are discussed. Environmental legal developments have resulted in liability facing directors and senior management in compliance matters .and in operating mining and other businesses because of changes in community expectations. In the next decade it is suggested there will be many drivers for more changes in the legal environment. Some of these are touched on including the changing roles of the Commonwealth and State Governments, the High Court as -law-makers and the changing relationships with indigenous people in Australia and in overseas countries. The changing legal environment for mining demands a national approach in many areas on the proposition that resource based industries are part of a national industry. The uniform law approach among the States has been taking place but this needs to further. An appropriate task force should be forward to review the entire legal structure and regulations affecting mining on a national rather than a State basis . The mining industry will need to work with expectations of a changing community which have powerful, but sometimes contradictory, interest groups.

Jan 1, 1997

By I Kolomaznik

Each technological process can be reduced on the transport networks, and namely on the parametric networks and the non-parametric ones. The parametric networks are created by the piping, electrical cables or channels. The non-parametric network is created by the ways, suspended grooves, trackages and also by the belt conveyors or other conveyors for continuous material transport. If we reduce the technological process on transport networks, then, by the creation of these networks models and their mutual interconnection we obtain the model of the whole technological process. The model can be understood as the universal one, without exaggeration, because it is valid for any technological process. However, for us the mining production process is important what represents the mining and transport of raw materials under the support of the ensuring system. In this contribution one of the first attempt is described, and namely how to connect the parametric network which has been already worked out very properly with the non-parametric network what is presented in this contribution by the transport line of belt conveyors.

Jan 1, 2003

By R Nakia, R Livingstone

Historically the Goldfields of Victoria produced large volumes of gold. Interest in these historical Goldfields has grown over recent years with a view to restarting production of gold. A notable example of this is the Bendigo Goldfield. There is also interest in the Ballarat Goldfield and Ballarat Goldfields Ballarat East Project is a particular example of this. The aim of this paper is to describe the ventilation aspects of the potential Ballarat East project. The mine is proposed as a decline access. The paper gives an overview of the project and in particular the ventilation planning associated with a number of possible equipment scenarios. The paper also analyses the main ventilation pollutants that are likely within the proposed mine as it develops to increasing depth. An attempt is also made to determine the depth at which mine climate will become the dominant pollutant rather than diesel exhaust pollutants.

Jan 1, 2003

During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within North America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The traditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

Jan 1, 2005

A portable surface impedance meter has been tested extensively over a wide variety of geological formations both in Australia and elsewhere. It has proved a useful geophysical too] for relatively shallow mapping (i.e less than 100 metres depth) of faults, intrusions, dykes and conductive ore veins and can be used as a depth probe for overburden and glacial ice. Case studies involving coal seam mapping at Collide (Qld. Australia), galena ore vein location at Zeehan (Tas. Australia) and glacial ice probing on the Brewster Glacier (South Island, New Zealand) are detailed. The first results of a similar unit using a lower frequency with consequential increase in depth of penetration will be presented. The application of VLF measurements to monitor blasting in mines and in the location of earthquake epicentres will also he introduced.

Jan 1, 1987

By Isokangas T. A

With some two-thirds of the production exported, coal mining prac- tices of the last few years in Australia have been much influenced by the decline in the price received. It became essential to improve efficiency and rationalise operations. Trends in underground practice vary. On the one hand many additional longwalls have been installed and most recently the results achieved by them have shown a significant up-turn; this may be correlated more with increases in equipment capacity than with utilisation which has altered little during the past six years. Varied constraints remain affecting cur- rent and future longwall operations. On the other hand a number of mines have been closed whilst others have sought to improve results by various installations including miniwalls, shortwalls, and use of continuous haulage and mobile breaker line sup- ports. All mines continue to review working practices.

Jan 1, 1988