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Traditionally, surface coal mines in the Western United States have been limited by economics to depths between 150 to 200 feet. Utah International Inc., however, is now planning to strip coal its San Juan Mine in Northwestern New Mexico to depths ranging up to 400 feet while uncovering 20 feet of steam coal. This method is cost-competitive with nearby shallower coal deposits and underground mining of the same property. How trucks and shovels can pre-strip for a dragline, along with results of the planning process, comparison with alternate systems, capital requirements, operating costs and comparisons with other coal sources are all detailed. Also discussed are the major problems anticipated, how they might be corrected, and potential improvements to the concept. Introduction The San Juan Deep Stripping Project will be situated at Utah International's San Jean Mine. The mine is in the Four Corners region, so-called because four states enjoy a common border point about 30 miles to the northwest.(see Figure 1). The area is a semi-arid plateau region with an average elevation of 5,200 feet, receiving an average of 6 inches of precipitation annually

Jan 1, 1981

Direct smelting of copper in a single vessel has long been the extractive metallurgist's dream. Such a process offers the important alvantage. of (i) maximum use of the energy available from oxidizing the sulphur and iron of the concentrate: (ii) restriction of SO2 emissions to a single constant-strength source; (iii) minimum materials handling and (iv) elim-ination of at least one process step. Extensive developmental work was carried out in the 1960's and 1970's to implement such single-step processes. Some of the processes reached the prototype stage and it appeared that copper smelting technology was on the thresthold of a new, efficient, minimum-pollution era. Since that time, however, the forward thrust has slowed and single-step copper smelting is still a process of the future.The paper describes the potential advan-tages of single-step smelting; its history and current status; and the reasons why it has not been adopted industrially. It concludes that the potential benefits of single-step smelting are powerful and that many of the difficulties encountered in the 1970's will be overcome in the 1980's.

Jan 1, 1985

By I KylmSkorpi, H Mansikkaviita

The traditional direct-heated drying process has been replaced by the steam drying process in non-ferrous metal smelters, where steam is available from waste heat boilers. Many recent projects have selected Kumera Steam Dryers in equipping a new production line or modifying an old production line. The industrial performance of the steam dryers has shown significant energy saving and emission reduction. The steam dryers have been operated at high availability and long maintenance interval. As the process principle of Kumera Steam Dryer is different from other equipment, the set-up for steam dryer plants is configured to fit the smelter site and operation conditions to achieve optimal performance. This article discusses the equipment involved in the steam drying process and their combination options.

Jan 1, 2008

By J B. Pateiro-Fernßndez, M Fuchsschwanz, G Deissmann, S Ahmad

Quang Ninh province is the most significant coal producing region in the north of Vietnam. The Nui Beo Coal Company (NBCC) operates open pit mines in Quang Ninh province and the waste overburden produced is dumped as sidehill fill in the Chinh Bac waste dump site. In the past, no special consideration has been given to the environmental impacts during the dumping operations. The mine waste is transported in trucks from the mine site to the dumping site and the loading, hauling and dumping operations are the main sources of dust emission. Rain events, especially during the rainy season, cause the generation of contaminated surface water as well as seepage of water through the dump at a number of locations. The existence of cracks at the top of the dump can pose serious stability problems with heavy rain events leading to failure of slopes which can potentially disturb vast areas of land currently used for agricultural purposes and human settlement. For sustainable development at the Chinh Bac waste dump site in the future, apart from the social and economic considerations to be assessed, there is an absolute necessity for environmental protection measures to be in place both during and after the dumping of the mine waste overburden. Research Association Mining and Environment in Vietnam (RAME) is working to develop and implement concepts for the mitigation of environmental problems emerging from dust, contaminated water and lacking slope stability to ensure successful rehabilitation of the coal mine waste dumps in the north of Vietnam. Within the framework of RAME, the Institute of Mining Engineering I (RWTH Aachen University) is managing and working to develop the stabilisation concepts for the solid mine waste dump in collaboration with the Chair of Geotechnical Engineering (RWTH Aachen University), Brenk Systemplanung and the Vietnamese group of companies VINACOMIN (Vietnam National Coal-Mineral Industries Group). The most economical and environmentally sound operations, as well as locally adaptable environmental protection measures, are essential for the sustainable development of the dumping operations at Chinh Bac dump. This paper describes the dump site and the sustainable development possibilities with an emphasis on the environmental protection and stability problems at the Chinh Bac waste dump.

Jan 1, 2009

The implementation of the Mining Further Amendment) Act, 1970, and later the Coal Mining Act, 1973, placed a requirement on the Department of Mines to accept an initiative in relation to coal exploration and coal mine development which does not apply in the case of other minerals. It is necessary to consider the exploration of the total coal resources of the State when considering exploration rather than one individual basin or deposit. If the level of knowledge of the coal resources in these basins is considered in relation to their potential for development it is possible to allocate broad scale priorities to their assessment. Due to the enormity of the task which involves a conservative estimate of in excess of 400 000 m of drilling to reach a broad reconnaissance level of understanding the involvement of industry with the Department in the exploration programme is necessary. The development of the coal deposits by mining operations must give consideration to a number of constraints apart from the simple availability of the resources. Principal among these are aspects

Jan 1, 1976

By J Lane, D J. Barker, B Pei

Queensland Alumina Limited (QAL) is the worldÆs largest producer of smelter grade alumina, located in Gladstone, Queensland, Australia. The plant employs evaporative cooling towers for waste heat rejection. Process water requirements include red mud residue disposal, steam venting to the atmosphere and Calcination feed moisture. Raw (untreated) water consumption in 2001 was 37 700 m3/d or 3.8 m3 per tonne of production. The Gladstone region experienced a water shortage in the period 2001 to 2003, resulting in progressive water restrictions. Industry operated under a ten per cent restriction from April 2002 and in November 2002 a 25 per cent restriction came in force. The maximum restriction level of 50 per cent was anticipated for the middle of 2003. Water restrictions of these magnitudes have the potential to result in significant production limitations, which would have major economic consequences for QALÆs owners, customers, suppliers and employees. Therefore it was imperative that measures be found to mitigate the impact of these restrictions. Furthermore, as one of the largest water users in the Gladstone region, QAL had an obligation to the community to minimise water usage as much as possible. A thorough analysis of water usage on site was conducted, focussing on all water streams leaving the plant. The philosophy used was that by minimising water outputs, the inputs would follow suit. Where possible, preference was given to solutions that provided lasting water savings. This occurs when the value of the water saving justifies the project cost, irrespective of water restrictions. By June 2002 an average water saving of 19 per cent was achieved, almost double the required saving. By end November 2002 further projects had increased the total water saving to 29 per cent, mainly through the re-use of GladstoneÆs municipal treated effluent as wash water. Further measures to reach the target of 50 per cent reduction were investigated. The evaporative cooling system was to be replaced with seawater cooling, using cooling towers to minimise the seawater pumping cost. Another benefit of this concept was the ability to dispose of the cooling tower bleed stream with the existing system for neutralised red mud disposal. This would avoid the need for an additional environmental outfall from the plant. In February 2003 the Gladstone region received over 500 mm of rain, which boosted water reserves to five years supply at forecast usage rates. This led to the lifting of all water restriction. As most of the implemented water savings measures are economically viable in the absence of water restrictions, raw water usage at QAL is still less than 75 per cent of pre-2002 levels.

Jan 1, 2003

By Bahsford A

The presence of coal in the Sydney area was confirmed in 1891 when Cremorne Bore No. I intersected cindered coal at 1 854 m. The decision to develop Sydney Harbour Colliery was based on the results of Cremorne Bore No. 2 (drilled in 1892) in which a 3.12 m. seam of unaltered coal was encountered at 889 m. Geologists from the New South Wales Department of Mineral Resources consider that this seam is probably equivalent to an upper split of the Bulli seam. Long Cove at Balmain was selected by Sydney Harbour Collieries Ltd. as the site for mine development in 1896. This was due to opposition to the proposed establishment of a colliery on the north shore of Port Jackson near Cremorne. Construction of the main access and ventilation shafts (termed Birth- day and Jubilee), other mine infrastructure and the quay wall occurred between 1897 and 1902. A fatal accident in which five men were killed occurred during the construction of the Birthday Shaft in 1900. This acci- dent resulted in amendments to the Mining Act providing for guide rails in shafts.

Jan 1, 1988

By C Sylvestre

Leaders have invested heavily in traditional safety management to improve safety performance over the years. This primarily involved: • fixing the environment (eliminating the hazard) • improving the system (more/less rules, procedures etc) • making safety more conscious (more/better interactions about the importance of safety). These approaches have helped improve safety performance significantly during the last 50 years and will continue to play a role in the future. Although these approaches may be part of an overall solution, they are not enough to prevent many incidents. Today, these three approaches are used more than before, and are used better than ever before. Yet, workplace fatalities in Australia have stagnated from 2013 to 2019, as have the number of incidents, even serious ones. In the USA, workplace fatalities have increased by 15 per cent in the same period.

May 5, 2022

By Curless JM, Power SG

Polymetallic hydrothermal veins of the Western Cascades are hosted in propylitically altered Tertiary volcanics of calc-alkaline affinity and (or) in nearby, altered, and compositionally similar plutons. Ores from shallow and now abandoned mines produced mostly gold and were considered to be of epithermal origin. However, recent discovery of breccia and porphyry types of Cu-Mo mineralisation and other data suggest that the deposits of this terrane vary systematically both regionally, south to north, and locally, high to low altitudes. The evidence includes changes in (1) size, composition, and complexity of plutons, (2) types of mineral deposits; (3) assemblages of alteration and ore minerals; (4) trace metal geochemistry of host rocks; and (5) fluid inclusion and sulphur isotope data. They collectively imply a consanguineous origin of vein, breccia, and disseminated-veinlet types of mineralisation by magmatic hydrothermal processes.

Jan 1, 1987

By A Karrech, C Schrank, O Gaede, I Canbulat

Strain-based failure criteria have several advantages over stress-based failure criteria: they can account for elastic and inelastic strains; they utilise direct, observable effects instead of inferred effects (strain gauges versus stress estimates) and they model complete stress-strain curves, including prepeak, non-linear elasticity and post-peak strain weakening. In this study, a strain-based failure criterion derived from thermodynamic first principles utilising the concepts of continuum damage mechanics is presented. Furthermore, implementation of this failure criterion into a finite element simulation is demonstrated and applied to the stability of underground mining coal pillars.In numerical studies, pillar strength is usually expressed in terms of critical stresses or stress-based failure criteria where scaling with pillar width and height is common. Previous publications have employed the finite element method for pillar stability analysis using stress-based failure criterion, such as Mohr-Coulomb and Hoek-Brown, or stress-based scalar damage models.A novel constitutive material model, which takes into consideration anisotropy as well as elastic strain and damage as state variables, has been developed and is presented in this paper. The damage threshold and its evolution are strain-controlled, and coupling of the state variables is achieved through the damage-induced degradation of the elasticity tensor. This material model is implemented into the finite element software Abaqus and can be applied to 3D problems.Initial results show that this new material model is capable of describing the non-linear behaviour of geomaterials commonly observed before peak strength is reached as well as post-peak strain softening. Furthermore, it is demonstrated that the model can account for directional dependency of failure behaviour (ie anisotropy) and has the potential to be expanded to environmental controls such as temperature or moisture.CITATION:Gaede, O, Schrank, C, Canbulat, I and Karrech, A, 2014. A strain-based failure criterion for pillar stability analysis, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 393–398 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

Universities have had a long history in the education of geology graduates, Analysis of this history reveals a record of success, as judged on a world basis. However there have been significant changes in the last 20 years that have impacted on the ability of universities to continue to provide their traditional style of geology education. These changes have increased in the last 10 years. In the teaching side, there has been a change in expectations. Additionally the increasing workload decreases the value of each academic to perform the tasks needed by the new education. In the area of research, the funds provided have continued to decline, in both real and absolute terms, and it is now necessary for universities to seek out funds to pay for their postgraduate research. Additionally, the universities have slipped into the error of what cahn only be termed "academic incest", and research student mobility has decreased to an undesirable level, stifling initiative and new ideas in a number of cases, The only solution is for Government monies to be "directed" - ie that the postgraduate student must leave his or her original university in order to receifve the research stipend/scholarship. On the government front, the government and its agencies have not adequately analysed and recognised the need for the redirection of education and research funds into the needy areas of science and technology, especially those that related to the minerals area.

Jan 1, 1986

A real Dorothy Dix title has been selec- ted for this paper. It has the advantage, however, of being capable of being interpreted in many different ways and hence I can select my own approach. You probably are thinking that this topic would be more appropriately handled by an Accountant. I wish to make it clear at the outset that I am not skilled in the sometimes mysterious ways of Accountants - likewise that profession frequently has difficulty in pinning down economists. We have our own strange ideas about profits, marginal efficiencies, cost/benefit analysis etc. What follows is in the main a mixture of two disciplines, probably in a form that few of the purists from either side would accept. Nor do I expect the reader to accept my own prejudices. The paper is designed to stimulate thought and discussion'on the subject. Emotive words such as "profit" and "loss" make for wide differences of opinion. At the time of writing there is a surprising degree of acceptance of the viewpoint that profits in Australia are too low and one is tempted to make this point of near agreement a starting Point.

Jan 1, 1975

The last two years have seen a rapid change-over from mechanised cut and fill. stoping to the more economic and productive long hole open stoping method, such that today more than 80 per cent of total production is won from open stopes. At first drilling was by sub-level rings and/or parallel up and down holes from inter- mediate sill horizons using conventional exten- sion rod equipment. Sub-levels were developed no more than 40 metres apart to allow accurate drilling. Compact, crawler mounted in-the-hole hammer equipment was introduced as soon as it became available in Australia. Today, all open stope drilling is done with three Atlas Copco ROC306 rigs and two Ingersoll-Rand CMM jumbos. Fans of 115 mm diameter holes, varying from near vertical down holes to horizontal, are drilled with a burden of 3 m. Toe spacing varies from 3.5 m to 4 m. An Atlas Copco DG418 booster compressor is used to boost run-of-mine air from 700 kPa to 1400 kPa in the areas of longest drilling. This has improved overall drilling performance in these areas by 40 percent.

Jan 1, 1977

By M Dietrich

The paper describes an efficient method for analysing the different attachment kinematics of excavators and other linkages by taking into account digging forces, the workspace and the stability of the machines. The different attachment kinematic systems of hydraulic excavators and a æclassical analysing methodÆ will be presented. The method was integrated as a plug-in for the multibody simulation (MBS) software MSC.ADAMS to create an easy to use solution for design engineers. A comparison of the new MBS-solution with the classical static analysis is a part of this paper and shows the advantages of the new method. This takes into account the manifold and new dynamic analysing opportunities, as well as more detailed models leading to more accurate results.

Sep 26, 2011

By Kobayashi M

Particulate chalcopyrite samples (78 ~ 98 mole per cent chalcopyrite, screen size fraction from 710 to 250 µm) were prepared by crushing and sieving lump ore samples from 12 locations in the Mt Isa Mine. Measurements of thennoelectric power (which does not involve the passage of a current) were made using a packed bed that was compressed by loading with a weight and placed in a temperature gradienL Details of the apparatus are described.The effect of particle size was investigated by preparing 12 fractions, with mean particle sizes ranging from 605 to 2.2 µm, from one of the ore samples. Values of thennoelectric power decreased with both increasing particle size and loading pressure; however it remained fairly constant for particle sizes above 80 µm, when loading pressure exceeded 3.3 MPa.Measurements of the chalcopyrite samples gave an average value of -260 JlV/K (-248 ~ -268 µV/K) for nine samples and about -290 µV/K for three samples, showing that these samples were all n-type semi-eonductors.

Jan 1, 1990

By H Kurth

Mining geologists utilise many technologies to map, sample, measure, model and plan before and during the mining process. Predicted ore quality rarely corresponds with feed quality determined by process operators. Objectively measuring conveyed material quality accurately in real time avoids disagreements over mined ore quality and generates opportunities to improve mill feed quality.This paper discusses the well proven PGNAA (prompt gamma neutron activation analysis) technology used in the GEOSCAN-M elemental analyser that is ideally suited to measuring composition of primary crushed conveyed material in real time. Representative, continuous, fully penetrative measurements are unaffected by particle size, belt speed, mineralogy, dust or layering on the conveyor. Material can be directed to processes or stockpiles by utilising measurement increments of typically one to five minutes and then activating diverters to direct increments to the correct location. Waste, low-grade or deleterious material can be rejected to waste dumps or stockpiled for later processing. Material meeting a product specification can bypass unnecessary processing. Paybacks in weeks have been achieved for such applications. Process operators are able to control the blend of ores fed into the mill to improve processing performance and use measurements for ore reconciliation and metal accounting. Utilising the technology to upgrade ore quality after mining and before processing is beneficial in improving plant economics.The technology has been successfully utilised in base metals, ferrous metals and industrial minerals. Mining geologists can determine ore quality being produced in real time and modify the ore quality prior to milling. Ore feed quality measurements are also used by process operators in optimising plant performance. The elemental content can help identify geometallurgical domains as well as other major changes in quality, which may affect processing. This paper outlines proven applications and case studies and proposes some innovative applications.CITATION:Kurth, H, 2017. Measuring ore quality using real-time on-belt elemental analysis – more than grade control, in Proceedings Tenth International Mining Geology Conference 2017, pp 213–220 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By Kewu W

Kaolin used as an industrial mineral, especially that in the paper-manufacturing industry, must be of fine size, with high brightness, a low impurity content, and good crystal shape. However, in most kaolin deposits there are various impurities which have a very bad effect on the quality of the kaolin. Therefore, it is necessary to remove these impurities from kaolin ore. Owing to their similar surface properties, the separation of kaolin and iron oxide minerals, especially microkaolin and iron oxide minerals, has been regarded as difficult. The iron oxide minerals often intergrow with kaolin in fine and complicated forms, such as thin films, which make separation difficult. In order to overcome this difficulty, many workers have suggested various treatment methods and obtained great success. Based on research work by Fuerstenau (1980), Huang, Li and Hu (1984), Hui and Wei (1991), Shergold (1978), and Zambrana et al (1974), we have investigated a two-liquid flotation technique for iron removal from kaolin and obtained some success.

Jan 1, 1993

Over the past 12 years screening of materials has undergone a dramatic change in both the types and materials used in screen mats and the quality requirements of the finished product. With the main thrust now on quality and a cleaner product a different approach was needed in the operation of sizing screens. New screen mats with many different aperture configurations have been developed using rubber and plastics.to replace the traditional screen mat of woven wire or punched plate.

Jan 1, 1984

This paper will address this question from the point of view of a drill and blast engineer or researcher working in open cut and underground mining operations. The paper will establish a common set of reference standards for high-speed imaging and data capture, which engineers and researchers can apply when deciding which type of imaging technology is appropriate. It will present an overview of current image analysis technologies and practices in use across a range of appropriate scientific fields and draw lines of commonality of approach between these fields and the field of mining and blasting applications analysis and research. In addition, the paper will examine the different technologies from an image quality and data stream reference point, ease of operation, cost, and reliability parameters. Finally, this paper will present an argument for the hybridisation of established and new technologies which could provide a more beneficial approach to the use of imaging as a tool of quality control, research and analysis in the mining based industries. This will include a novel approach to digital high-speed imaging and data analysis in the field, which should deliver high-quality images and data analysis in a time frame that is more appropriate to the need for immediate action, analysis and problem solving.

Jan 1, 2007

By C Moorhead, J Jones

A common problem in the mining industry is that company geologists can operate in relative isolation to the rest of the company (Jones and Moorhead, 2011). This may result in poor knowledge transfer and often priority conflicts with geology, operations and project departments. This problem is amplified by the acquisition of mineralogy capabilities and other metallurgical (met) test work undertaken by many companies in order to solve for complex orebody problems. Met data is often not located and viewed in 3D space so that geologists and engineers can create and work with geometallurgical (geomet) models (Bye, 2006). Visualisation of data in an interactive graphical 3D model provides a bridge enabling met professionals to collaborate with engineers and geologists to provide a common understanding of the relevance of geomet data.In recognition of this problem, Newcrest has undertaken an effective collaboration strategy to improve internal and external engagement through the use of large visualisation displays (Jones, 2009). The displays are underpinned by IT systems and information management practices that recognise the needs of underlying disciplines. Today it is generally understood within Newcrest that this is required to improve decision-making, deliver faster cycle times and improve governance.Collaboration in companies has been generally associated with the introduction of new IT functions (IBM, 2008). However, the science and engineering process that are used to structure modern IT-based collaboration systems and practices are now known to be simplistic compared to the long-standing practices associated with collaboration and knowledge management in disciplines such as geology and mining.CITATION:Jones, J and Moorhead, C, 2013. Geometallurgical communication as a distributed information system, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 133-138 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013