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Mount Read is 'situated in the county of Montagu, on 'the west coast of Tasmania, about 20 miles inland from. Remine in an easterly direction, 15 miles northerly from Mount. Lyell, and 30 miles south-east from Mount Bischoff, and is one of the mountains forming the west coast range; it rises to a height of 3890 ft. above sea level.About eleven years ago the first mineral section was taken up on Mount Read by a Hobart company, known as the Mount Reid Silver Mining Company, consisting of 25,000 shares its holding consisted of one section of 80 acres, held under mineral lease. Prospecting was carried on for some months under great disadvantages, as all supplies had to be carried up the mount from Dundas, a distance of nine miles, on men's backs, until a pack track for horses was made.The track rises 2500 ft. in the first five miles, and then falls 200 ft. from that point to the mines, which are at an altitude of 3000 ft. above sea level, and at a point about two miles westward from the summit of the mountain, approximately midway between Mounts Read and Dundas.

Jan 1, 1901

By Ray Hutton, Darrell Liebno, Taro Nonaka

Background Population growth and increasingly stringent regulatory controls on water quality across North America have resulted in municipal governments investing heavily in infrastructure to control what are known as Combined Sewer Overflows (CSOs).These are events which occur when combined sewers exceed their conveyance capacity during periods of heavy rainfall or snowmelt. The city of Atlanta, Georgia is one such municipality; with a population of over450,000 within city limits and a sewer system servicing 1.2 million including adjacent jurisdictions, the City of Atlanta has a Combined Sewer System (CSS) encompassing approximately 15% of its total 3,540 km (2,200 miles) of sewers. Atlanta’s CSO discharges to local watercourses began to draw fire from environmental groups in the1980s. As a result, in the early 1990s, the City constructed a series of CSO control facilities which provided screening and chlorination at seven CSO discharge points across the CSS watershed. Unfortunately, these facilities were not capable of handling all of the overflows generated due to heavy storm events; frequently, untreated water was bypassed around the treatment facilities. The federal Environmental Protection Agency (EPA) deemed that water quality standards were being violated by these discharges, and a suit was brought against the City to force a higher standard of compliance. As a result, the City entered into a federal Consent Decree which would bring CSOs into compliance with federal standards by 2007. A critical component of this plan was the design and construction of the West Area CSO Tunnels and Pumping Station. In February 2003 the City’s Department of Watershed Management retained the services of Jordan Jones & Goulding/Hatch Mott MacDonald/Delon Hampton Associates (JDH Joint Venture) to design and provide construction management ser-vices for the project, which was designed to capture combined sewage from three of the City’s existing CSO facilities on the northern end of the CSS watershed. The design consisted of two connected tunnels which would convey the wastewater originating from the North Avenue, Clear Creek, and Tanyard Creek CSO facilities to a submersible wet well pumping station located at the R.M. Clayton Water Reclamation Center (WRC). Since the majority of the effluent stream consisted of storm water, the City elected to design and construct a separate treatment plant. This plant was designed under a separate contract, and is currently under construction.

Jan 1, 2007

By Dennis R. Dolinar, John L. Ellenberger, Gabriel S. Esterhuizen, Anthony T. Iannacchione

A survey of pillar conditions was carried out at 21 operating limestone mines that use the room-and-pillar method. The surveyed pillars were all located in rock that was classified as “Good” to “Very Good” using the RMR rock mass classification system. The average pillar width was 14.5m and the width to height ratio varied between 0.53 and 3.52. Pillar conditions were rated using a visual rating system that accounts for the effect of geological structures as well as stress related fracturing. Nine cases of pillar instability were recorded. Pillar instabilities were typically limited to individual pillars or small groups of pillars within an otherwise stable layout. Local geological structures such as inclined discontinuities or weak bedding planes contributed to instability in seven of nine cases that were observed. Elevated pillar stresses contributed to instability in the two remaining cases. All the unstable pillars observed had width-to-height ratios of less than 1.5. It is concluded that pillar instability is most likely to be caused by unfavorable geological structures in pillars with width to height ratios of less than 1.5. Stress related instability such as rib spalling becomes more prevalent when the average pillar stress approaches approximately 20 MPa.

By E K. Leeka

Process control limitations have led to suboptimal performance of the crushing section of Sishen MineÆs Jig Plant. The performance of the PID (proportional-integral-derivative) controller implemented during commissioning was hampered by the relatively small buffer capacity between the crushers and screens. The inability to maintain the tertiary crushing chamber under full choke conditions lead to inefficient crushing and reduced crusher product cubicity.Model predictive control (MPC) was implemented in the tertiary crusher plant in May 2012 and resulted in a throughput improvement of six per cent in its first month. The controller was further optimised and indicated a throughput improvement of 16 per cent during on/off testing in July 2012. The throughput improvement is attributable to the finer crusher product resulting from operating the crusher under full choke conditions and controlled feed rate to the tertiary crusher plant screens. The next step is to couple the model predictive controller, automated gap control system and an economic optimiser to ensure maximised throughput and value from the resource.CITATION:Leeka, E K, 2013. Performance of model predictive control on the crushing circuit at Sishen Mine, in Proceedings Iron Ore 2013 , pp 417-420 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By Johnson I. R, Muir M. D

The Dugald River zinc-lead deposit is located 60 km northwest of Cloncurry. It was discovered prior to 1881, and since 1937, has been the subject of several drilling programmcs which have outlined a resource potential of 60 million tonnes grading 10 per cent zinc, 1 per cent lead, and 30 g/t silver.The deposit is a classical example of stratiform zinc lead mineralization in a black shale host. It occurs within a restricted clastic sedimentary basin within the Corella Formation of Carpentarian (Middle Proterozoic) age. Sabkha, lacustrine and fluvial sedimentary environments have been recognized within this basin. Each environment is characterized by suites of evaporite mineral pseudomorphs, after both shortite and gypsum, indicating that both alkaline and hypersaline environments prevailed at different times during basin evolution. The Dugald Slates which host the zinc-·lead mineralization are lacustrine in origin. Thin Mount Isa-type K-rich tuffite beds occur in the Dugald Slates and in the sabkha sequences.The basin as a whole appears not 10 have been marine, and 10 have had strong tectonic controls on its depositional history.The mineral deposit itself is conformable within the Dugald Slates and many primary sedimentary and soft-sediment deformation structures are preserved. It has a strike length of 2 km, average width of 10 m, and a westerly dip of 50-80 . Drilling suggests continuity to 1000 m vertical depth. The predominant sulphides are pyrrhotite, pyrite, sphalerite and galena in graphitic slate and quartz-carbonate ganguc. Anomalous concentrations of barium, manganese, cadmium, mercury and antimony are present in the ore.The deposit crops out over a distance of 2 km as a gossan ranging from 5-15 m in width. There is a striking vegetation anomaly over the gossanous outcrops. The gossan is enriched in lead, silver, antimony, barium, titaniulll, silica and iron, with respect to the primary mineralization. The depth of total oxidation reaches about 20 m.Cieochemical and geophysical test surveys over the deposit give pronounced anomalies.

Jan 1, 1982

By Vincent A. Scovazzo

On March 12, 1994, the 1,100-foot deep 2 Yard South panel of the 1l0 year-old Retsof Mine collapsed. At the time of this occurrence, the Retsof Mine was characterized as the world's largest, most productive salt mine. The collapse produced a seismic event and resulted in a sinkhole and small lake forming on the surface. An existing highway bridge was rendered unusable. Water entered the mine and despite valiant efforts by the miners and the mining company, the entire mine was flooded and lost. John T. Boyd Company (BOYD) studied the incident to evaluate design procedures, and assess the short- and long-term environmental impacts of the collapse. This paper presents our analysis of the cause of the collapse and our review of the rock mechanics design of 2 Yard South panel. Our review is, in part, based on a rock mechanics monitoring program of 2 Yard South. The monitoring program was established by the mining company as the panel was developed and continued even after the panel became unstable.

Jan 1, 1997

By Cesar Sáenz Acosta

El presente texto señala las mediciones de impactos que se han realizado a los programas de responsabilidad social de una empresa minera. Esta medición se realizó a través del cálculo del indicador “Retorno social de la inversión”, aplicando el modelo SROIM o Gestión del Retorno Social de la Inversión. Los proyectos de RS medidos permiten actuar a las empresas de manera responsable con su comunidad y comprenden: salud y nutrición, educación y desarrollo económico. Asimismo, esta medición contribuye a mejorar la comunicación de los impactos generados y desarrolla una gestión adecuada de estos.

Sep 12, 2011

By P. Schilizzi, A. Jarosz, M. Karmis

This paper is concerned with subsidence prediction methods and in particular with two techniques, one based on profile functions and the other on influence functions. Profile function methods provide a tool for a fast calculation of subsidence on a line across a mine panel. Influence function methods, on the other hand, allow for a more detailed calculation of ground movements, in any mode and at any depth, on a grid or at any specific point. In more detail, the hyperbolic tangent profile function, as developed by VPI&SU from field data pertaining to the eastern U.S. coalfields, and an influence function method currently being adapted for the same region, are presented and discussed. The applicability, advantages and limitations of these techniques are examined and comparisons are presented with field measurements. Computer software developed for the application of these prediction methods, for two widely used personal computer systems, are also discussed and a number of examples are presented demonstrating the potential of such programs.

Jan 1, 1986

The Bayswater seam of the Singleton Coal Measures is discussed in relation to its field occurrence and related li~hotype profiles. The seam is correlated throughout widely separated areas of the Hunter Valley with the Farrells Creek seam at Howick, Broke seam at Broke, and Saddlers Creek seam at Mt. Arthur. The unusual features of composition of the seam in relation to adjacent seams is dealt with in terms of the seam environment, particular attention being given to the sandstone at the base of .the seam. Petrographic and other data are used to support the arguments submitted.

Jan 1, 1973

By J. A. Every-Brown

Case studies are presented of three derelict sites in Kent and Essex that provide a good cross-section of opportunities for second-generation commercial uses of former chalk, limestone, clay and gravel workings. A 240 ha abandoned chalk quarry at Grays in Essex, now known as Chafford Hundred, is undergoing mixed development to include leisure facilities, a range of housing and commercial areas and an enhanced environment. The 120 ha of Stone Marshes now comprises the Crossways business park and the Dartford international ferry terminal. Reclamation and servicing required more work than had been anticipated and the fact that the area was within the green belt added to the delays, but Blue Circle was eventually able to provide a comprehensive development of the entire area to a high environmental standard. Stone Pit 1 landfill, at Dartford in Kent, is a former chalk quarry 40 ha in area and with an original average depth of 35 m. Landfilling commenced in 1976 and during the period 1979-1984 the site operator designed, developed and installed a gas collection and flaring system. From 1986 a gas plant supplied up to 5 000 000 therm/yr of landfill gas to a local cement works and in 1989 a 1 MW power generation scheme, later expanded to 3 MW, was commissioned. Gas is currently also supplied to a metal refining company for use in internal combustion engines

Aug 1, 1994

By Bengt L. Stillborg

INTRODUCTION This paper summarizes the result of a two and a half year research program. The objective of the research was to develop a fundamental understanding of the Rib-in-Roc method. Through the development of a new model technology, namely three-dimensional physical models which powerfully exploit the results of dimensional analysis Stillborg, Stephansson and Swan (1), it has been possible to establish the contribution to both permanent and immediate stabilization of a large underground opening pre-reinforced by the Rib-in-Roc method. Using the results from these physical models and earlier work by Stillborg and Stephansson (2) and Åkesson (3), a conceptual synthesis is given in this paper so demonstrating the Rib-in-Roc method to be a practical working system of pre-reinforcement. DESCRIPTION OF THE RIB-IN-ROC METHOD To give the reader an idea of how this method of pre-reinforcement is performed, a short description will be given, Figure 1. Before any full-scale excavation takes place an entry is made in the host rock and rib raises are driven around the proposed opening. These raises are made at a spacing that is dependent upon rock quality; an opening in poor rock needs more ribs per length of opening. As the ribs are driven they are used as a site from which very competent rock bolting can be done. As a rib is excavated it is filled with reinforced concrete. Finally after having in this way reinforced the zone around the proposed opening, (a reinforced arch is formed) the displacements are automatically controlled as the opening is being excavated. Using this method openings with a span of 50-60 meters (160-200 ft) and a height of 60-80 meters (200-260 ft) are likely to be realised.

Jan 1, 1979

By K. Duckworth

"Comparative tests of the conventional Turam survey configuration and an alternative configuration called the Tx-parallel configuration were conducted at the McClean uranium deposit in northern Saskatchewan. Both configurations detected the known conductors at the site but the alternative configuration demonstrated its particular effectiveness in the reconnaissance role. This effectiveness results from the fact that the length of Tx-parallel traversesis controlled only by the length ofthe transmitter and not by its power. In addition, the field strength along a Tx-parallel traverse is uniform unless the traverse approaches the end of the transmitter. This freedom from a strong gradient of the primary field along a Tx-parallel traverse eliminates the gradient-induced anomaly shifts which are common in conventional Turam operations. The locations of each of the McClean conductors, that were obtained from the Tx-parallel profiles, werein better agreement with the locations known from drilling than were the locations obtained from the conventional profiles. However, the conventional profiles gave better estimates of the conductance of the targets.The results obtained over the McClean conductors indicate that current gathering has a strong influence on Tx-parallel results with consequent unpredictable influence on depth and conductance estimates. However, the depth estimates obtained from the Tx-parallel data appear to be in good agreement with the known depth of the McClean south conductor. The Txparallel results provide shallow estimates of the depth of the McClean north conductor which suggest that the fracture zone above the graphitic conductor is a significant conductor as was also suggested by earlier VLF surveys.Comparison with the wide range of published geophysical test surveys for the McClean site showed that apart from the work required to lay the transmitter, the Tx-parallel mode of operation of a Turam exploration system is operationally very similar to a moving source Slingram type of survey. At the McClean test site, it provided the same depth of exploration as a conventionally deployed fixed loop transmitter."

Jan 1, 1988

By Bin Feng, Xiang Fang, Tao Guo, Fandong Lu

Abstract: Rough set theory (RS) can find useful information from a large number of data and generate decision rules without prior knowledge. Support vector machines (SVM) have good classification performances and good capabilities of fault-tolerance and generalization. To effectively control blasting vibration effect, prediction model of blasting vibration parameters based on rough sets and support vector machines are established. Particle swarm algorithm (PS) is used to dynamically discretize attributes. Then, according to the optimal particle calculated by the PS algorithm, the decision table is established. After eliminating less importance attributes and data, then SVM is trained and established for prediction. The model can deal with both quantitative and qualitative factors such as aperture and cast direction, and analyze their importance to peak vibration acceleration value. The improvement of prediction accuracy is verified by testing data.

Jan 1, 2014

The paper is a general review of practice in design of sub-level open stopes in Northern Rhodesian copper mines and gives examples of some interesting developments during the last five or six years. It discusses the effect of hangingwall subsidence and the methods used to combat rock pressure on working areas.INTRODUCTIONAll producing mines on the Northern Rhodesian Copperbelt have large ore reserves and are designed for high rates of production. The three mines (Mufulira, Rhokana Corporation, and Roan Antelope) where sub-level open stoping is used, hoist from 250,000 to over 400,000 short tons of ore a month so that any stoping method used must be adaptable to concentrated' mining. Individqal stopes produce from 5,000 to over 25,000 short tons of ore a month.Structure af the ore bearing sediments is simple; faulting in ore is almost entirely absent and copper mineralisation is found in the same beds over great distances...

Jan 1, 1954

By T. Celik, B. Genc, C. Musingwini

"Mine planning software continues to be an important factor when it comes to the development of the South African mining industry. To contribute to this development, a new methodology to define and measure mine planning software utilization in the South African coal mining sector within an evolving data-set framework was developed. An initial data-set showing the mine planning software providers, their corresponding software solutions, as well as the software capabilities and information on the number of licences was collected and compiled in 2012 in an online database for software utilized in the South African mining industry. Details of the database development and implementation were published in the Journal of the Southern African Institute of Mining and Metallurgy in 2013. In 2014 the data-set was updated with additional and new information.In this paper, using the 2012 and 2014 time-stamps, a methodology for estimating the software utilization is developed. In this methodology, three variables: commodity, functionality, and time factor are used to define and measure the software utilization in order to ultimately inform decision making strategies for software utilization. Utilization in the coal sector was measured according to six different functionalities, namely Geological Data Management, Geological Modelling and Resource Estimation, Design and Layout, Scheduling, Financial Valuation and Optimization. The methodology is useful for stakeholders reviewing existing software combinations or intending to purchase new software in the near future and wanting to estimate the comparative attractiveness of a certain software package. These stakeholders include mining companies, consulting companies, educational institutions, and software providers. The work presented in this paper is part of a PhD research study in the School of Mining Engineering at the University of the Witwatersrand."

Jan 1, 2016

By B. S. Gottfried

This paper is concerned with possible transport mechanisms which occur during segregated burning (i.e., burning in an oil reservoir in which the oil-bearing formation is overlain by a "clean" porous zone containing only gas). ,Two analytical models are presented. In the first, burning is assumed to occur at the gas-oil interface, and the dominant mechanism is taken to be the rate at which oxygen diffuses to the interface. The second model assumes that combustion occurs within the clean zone, with the dominant mechanism being the mechanism of fuel deposition from the oil-bearing formation to the clean zone. ,Comparison of the results of the analyses with limited experimental data indicates that the latter mechanism is much more plausible. Both models are idealized representations of the actual process and are somewhat conjectural, however, owing to the lack of more definitive laboratory or field data. INTRODUCTION In recent years there has been considerable theoretical and experimental research directed toward understanding the recovery of crude oil by underground combustion. Although two different recovery schemes have been proposed, known as forward and reverse combustion, it is only forward combustion that shows promise of becoming a practical recovery technique.17 Most of the analyses of the forward combustion process have considered it to be pistonlike; i.e., oil is displaced by a vertical combustion zone which, with its ensuing gases, pushes die oil forward as the flame front is propagated through the reservoir.l-8,ll,l2,14-16 However, information gained in field pilot studies indicates that, at least to a certain extent, forward combustion proceeds in a segregated manner in oil reservoirs.10 An ideal segregated system is one in which the oil-bearing formation is overlain by a "clean" porous zone containing only gas. The location of the combustion zone in such a system is not immediately evident, although combustion is believed to occur either at the gas-oil interface or within the clean zone. In either case, the combustion zone may be horizontal and it moves in parallel rather than in series with the produced oil. The purpose of this paper is to explore the likely mechanisms by which segregated burning can occur, and to determine the sensitivity of the resulting models to changes in various physical parameters. Two governing mechanisms are considered: the case of a horizontal combustion zone at the gas-oil interface with the rate of combustion governed by the rate at which oxygen diffuses to the interface, and the case of combustion within the clean zone with the combustion process controlled by the transport of fuel from the oil-bearing formation to the clean zone. Both models are somewhat hypothetical and involve considerable simplification of the actual process. However, the results allow some preliminary understanding of segregated burning which is useful in the absence of more definitive laboratory or field pilot data.

Jan 1, 1967

In referring to two subjects of interest to the Members of this Australasian Institute of Mining Engineers, I would at the outset desire to express our gratification that to-day we are able to welcome as now united with ourselves, those members who until recently constituted the New Zealand Institute. It is hoped that the amalgamation so amicably arranged may be productive of the best results to all concerned, incorporated as this combination has been at the moment of the fulfilment of that greater political union, the Australian Commonwealth.Since last Annual Meeting held in Brisbane, we have come under the same roof as the Chamber of Mines of Victoria, and we entertain the hope that as that Chamber and this Institute possess so many interests in common in the encouragement and advancement of mining and metallurgical progress in these colonies, that much mutual benefit will ensue. There are many directions in which each body can assist the other, and I trust that a friendly co-operation will be maintained.It is gratifying to feel that in all the colonies a distinct movement is being made to increase the facilities for education in Mining and Metallurgy but if I may refer to our colony of Victoria in particular, we have to express the profound regret that in the means of education in the higher branches, we occupy an inferior position, and it is quite certain that we will continue to do so unless the Government is prepared to subordinate provincial considerations to the weightier.

Jan 1, 1901

For the purposes of this discussion it is assumed that contributors should express the thoughts that arise from their personal experience. So wide is the range of mineral deposits, and so varied the methods employed in their discovery and development, that no two geologists are likely to have been impressed with the same applications of their science. The author's own personal experience has been, during recent years at least, very largely concerned with the broader aspects of the employment of scientific method and geological knowledge to the problems of exploration and exploitation, for the guidance of the general public and governmental authority rather than of mine executives and directors. The view-point thus reached is likely to differ in many respects from that of men who are much more intimately concerned with the mining problems of a single metal or a single mining field, and for this reason a statement may perhaps supplement those from others whose experience has been markedly different.It may well happen that, at some not distant date in the future, when systematic and comprehensive instruction in economic geology is embodied in the courses- prescribed for mining engineers during their years of training, the author's comments will be quitesuperfluous; but at the present time they appear to him to call for expression.The Need for Training of Mining Men in Economic Geology.Contact over a period of many years with mining men who have had different kinds of training and experience has been convincing that there is a general reluctance to acquire a full rational understanding of the geological factors involved in exploratory and developmental problems. The correction of this attitude is regarded as vital to the industry and it is necessary to insist that the outstanding requirement of the present day is the utilization of all branches of geological, investigation in the field and the laboratoryby men who have had systematic and specialized training in these matters. The science of geology is many-sided, but is, nevertheless, whole and essentially indivisible. No one can afford to disregard any fraction of its content 'or any of its methods of investigation.The greatest advances have been made in the understarnding of the occurrence of mineral deposits by those whose knowledge Qfbasal principles, has been soundest, whose endeavour has been to ascertain all their relationships in space and time, whose attention to detail of all kinds has been keenest, and at the same time, whose capability to distinguish between major and minor features has been most marked.With the passage of the years and the accumulation of data from many lands, it has been possible to build up a great body of information regarding the primary deposition and secondary alteration of mineral occurrences, which is of the utmost value in guiding thesearch for new deposits to take the place of those that become exhausted. This heritage is due not only to the efforts of gifted in...

Jan 1, 1950

By David Kress

Mill crushing drive systems are essential to cement producers. With the increased emphasis on operating efficiency, it is vital that these systems be dependable and reliable. No one needs the costs or headaches associated with unscheduled downtime or inefficient machinery operation. A reliable drive system starts with the proper selection of the ring, or girth, gear and continues through proper maintenance. Ideally, selecting the right girth gear brings together the gear manufacturer, the system designer and the end user. The gear manufacturer must know the details of the application, the demands that will be placed on the gear and the nature of the equipment to be driven. Similarly, the user and the system designer must be familiar with the variables that affect gear drive performance and service. For example, an application that places a torque load on the drive in excess of its rated capacity will result in gear tooth distress and, in severe cases, breakage.

Jan 1, 2000

By A. Sobhy

Froth flotation is a widely used, cost effective coal cleaning process. However, its high process efficiency is limited to a narrow particle size range between approximately 50 to 600 µm for coal and 10 to 100 µm for minerals. Beyond this range, the efficiency of froth flotation decreases sharply, especially for difficult-to-float coal fines of weak hydrophobicity (e.g., oxidized coal). This study was aimed at enhancing recovery of an Illinois fine coal sample using a flotation column featuring a hydrodynamic cavitation nanobubble generator. Nanobubbles that are mostly smaller than 1 µm can be formed selectively on hydrophobic coal particles from dissolved air in fine coal slurry. Results indicate that combustible recovery of a -150 µm coal was increased by 5-50% for different size fractions in presence of nanobubbles, depending on process operating conditions. Other major advantages of the nanobubble flotation process include lower collector dosage and air consumption since nanobubbles are produced from air naturally dissolved in water and they act as a secondary collector on particle surfaces, thereby resulting in considerably lower operating costs. Key words: Cavitation; coal; froth flotation; nanobubble.

Feb 27, 2013