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By R. E. Simpson

Beginning in 1972, fully grouted resin bolts were used in underground mines. An estimated 20 million resin bolts will be installed in 1980 owing to their apparent support improvement in most roof-bolt applications. Inorganic cements were tested to replace the resin at a lower cost while retaining the advantages of a grouted bolt. Although other inorganic materials were considered, all but portland and gypsum cements were rejected for reasons of availability, performance, or cost. Portland and gypsum-type cements were tested by the Bureau of Mines to select a fast-hardening, low-cost material that would anchor a roof bolt adequately to meet safety standards. An alpha-gypsum cement, accelerated with potassium sulfate, was selected as the best material because it had adequate pull strength at a desired set time of less than 5 minutes and was readily available.

Jan 1, 1980

By W. A. Wilkinson

In creating a surface mine design, a complicated series of events may be required to meet both mining and environmental objectives. Envisioning the mine at every step of the operation can greatly assist the engineer to identify design and operational problems that might otherwise go undetected until the field operations reach the problem. Providing operations a visual progression of the mine ensures that critical designs generated by the engineer are understood and effectively communicated to operations. Providing the plan as electronic data to the surveyors and/or on-board GPS systems can ensure successful implementation of the design. This paper discusses using computer technology to generate a virtual mine plan and strategies to consider when communicating a virtual mine plan through electronic and paper formats.

Jan 1, 2002

By John V. Simmons, Peter J. Simpson

Excavated slopes in open pit coal mines are designed to be as steep as possible consistent with stability and safety requirements. Slope failures occur for many reasons, including oversteepening. This paper is concerned with slope design and excavation experience in the Bowen Basin coalfields of central Queensland (Figure 1), [ ]

Jan 1, 2006

By R. N. Hambright

Gaseous and particulate exhaust emissions are characterized for a 1200 Bhp two-stroke cycle diesel, a 1000 Bhp four-stroke cycle pre-combustion chamber diesel, and a 900 Blip four-stroke cycle, direct injection diesel using steady-state modal testing and a versatile exhaust dilution-collection system. In addition, a 1.50 Bhp four-stroke cycle, pre-combustion chamber, turbocharged diesel was characterized for use in experimental water injection evaluations. Water injection downstream of the turbocharger compressor and upstream of the turbocharger exhaust turbine are evaluated for their particulate removal effectiveness on the small turbocharged diesel engine. The water droplets are inertially separated using cyclone separators designed for minimum pressure drop and outsize, lip to 50 percent of the total particulate mass generated was removed using a combination of both inlet and exhaust water injection techniques.

Jan 1, 1981

By D Wyatt, J Domenico, W Kow

Over the past few years developments in heavy minerals processing have concentrated on the mineral separation portion of the business. The best example of this would include new developments in rare-earth magnetic separators and associated flowsheet modifications. Except for some minor modifications in spirals, the æwetÆ side of the separation business has lagged behind the ædryÆ side. Basic concentrator design has not changed in 20 years. Recent pilot trials by Outokumpu Technology have shown the benefits of a new gravity flowsheet that combines density separation and spiral concentration on a variety of heavy mineral deposits. This concept is already well utilised within the iron ore industry. The synergistic combination of these two technologies allows smaller, simpler, and controllable gravity concentrators to be built while providing equivalent or better grade and recoveries of valuable heavy mineral. This is contrasted to the all spiral flowsheet characterised by the diminishing returns of multiple stages of spirals and associated recirculating loads. Examples of the flowsheets and associated benefits will be presented from a variety of cases.

Jan 1, 2001

By Irajá Bernardino Ribeiro Juniorr

O presente trabalho tem por objetivo apresentar alguns exemplos de aplicações na Indústria Siderúrgica e de Mineração (Prensa de Rolos e Torre de Resfriamento) mostrando que com o emprego de uma confiável metodologia para determinação dos benefícios energéticos é possível a implantação das medidas de conservação de energia em sistemas de força motriz instalados nestas indústrias com o simples uso de Lubrificantes Sintéticos Especiais em substituição ao largo emprego de óleos minerais. Esta solução também proporciona ganhos energéticos e financeiros expressivos e mais atrativos do que as já consagradas soluções de eficiência energética como troca de lâmpadas e /ou motores de alto rendimento. Além do mais, a troca de lubrificante já é rotina implementada nas indústrias e seus profissionais da área de manutenção, não sendo preciso treinamento adicional para implementação, tornando esta ação com o propósito de economizar energia simples e fácil de ser implementada. Este trabalho é uma parte dos resultados do projeto inovador desenvolvido pela Klüber Lubrication desde 2010, onde o principal objetivo é disponibilizar aos usuários de sua linha de produtos este recurso, internacionalmente reconhecido, de Medição & Verificação para a comprovação de ganhos de energia em prensas de rolos com alcance de redução de cerca de 10% de consumo de energia.

Aug 17, 2017

By Willem Le Roux

Occupational health and safety is regulated by statute and common law. South Africa has, like many other countries, legislated extensively on occupational health and safety. Despite the body of legislation, the common law continues to play an important role as far as it concerns contractual, delictual and criminal liability. Two major Acts regulate occupational health and safety viz. the Occupational Health and Safety Act, No. 85 of 1993 (?OHASA?) and the Mine Health and Safety Act, No. 29 of 1996 (?MHSA?). The MHSA applies to mines and works as defined and related aspects. OHASA applies to other industries but does not apply to employers and workplaces to which the MHSA and certain matters covered by the Merchant Shipping Act, No. 57 of 1951 apply. See section 1(3) of OHASA. 2 The employer?s health and safety obligations in terms of the MHSA 2.1 Section 2(1) of the MHSA provides amongst others, as follows: ?The employer of every mine that is being worked must: (a) ensure, as far as reasonably practicable, that the mine is designed, constructed and equipped: (i) to provide conditions for safe operation and a healthy working environment (ii) ... (b) ensure, as far as reasonably practicable, that the mine is commissioned, operated, maintained and decommissioned in such away that employees can perform their work without endangering the health and safety of themselves or of any other person?.

Jan 1, 2011

By F. Baerhold, S. Mitterecker

"Acid recovery is an important process step in pickling and leaching processes. Pyrohydrolysis in spray roasters and fluidized beds is a well-established technology to recover hydrochloric acid, but the hydrolysis in the liquid phase is more and more considered as an alternative new process route. The characteristic features of these three processes will be discussed along with select industry trends. For example, hydrochloric acid based leaching processes for ilmenite and nickel laterite ores produce far larger volumes of waste acid streams than the steel industry. Scaling-up of the spray roasting technology to the highest possible capacity is necessary in order to become more cost effective. In addition, process routes based on ferric chloride pyrohydrolysis allow the production of super-azeotropic HCl (up to 30 wt.%). Finally, the new ECOmode concept optimizes the operation of both pickling lines and the spray roast acid recovery plant. Long term results from industrial applications show that fuel savings in the spray roaster of 25% are easily achieved without additional process steps. An attractive feature is also to upgrade existing installations to higher plant capacities.INTRODUCTION Pyrohydrolysis is the conversion of metal halides into metal oxides at elevated temperatures in the presence of water vapor. Reaction products are a hydrogen halide gas and a metal oxide. The process was originally developed and introduced into the market by ANDRITZ Ruthner in the 1960’s. It has found wide technical application in the field of acid recovery and oxide production. The introduction of this process has revolutionized pickling technology. The use of hydrochloric acid has strongly increased over the last decades, since pyrohydrolysis is available for the total recovery of waste pickle liquors from mild steel pickling, as illustrated in Figure 1.Chloride media are also used increasingly in the metallurgical industry. Oxide production processes for Mg, Co, Ni, and Al have been installed. Processes using hydrochloric acid are known for the leaching of ores as well as for the re-extraction of metals from organic solvents. In both cases the recycling of HCl is of substantial importance to achieve highly economic processes and to reduce waste."

Jan 1, 2016

By D. E. Stephenson. Discussion by R. G. K. Morrison, L. Obert

R. G. K. Morrison (Chairman, Dept. of Mining Engineering and Applied Geophysics, McGill University, Montreal, Que., Canada) - The discing of drill core has been a recognized pressure phenomenon for many years but only recently has an interest been taken in the mechanism involved. The work of Jaeger and Cook is referred to in the text. The authors have now advanced the study to establish, within certain loading limitations, a direct relationship between axial and radial stress at failure. This is an important contribution. In mines generally, where pressure conditions result in the spalling of openings, the faces of drifts and crosscuts, on scaling, usually show a concavity with respect to the opening very similar to the face of the drill hole after the separation of the stub. The same holds for shaft sinks. This suggests a similarity between the mechanism of the discing of core and that of the spalling of an opening, under pressure, to develop a more stable outline. The latter, commonly regarded as shear, is the most conspicuous type of failure observed in

Jan 1, 1967

By H. Lawson

The Mine Safety and Health Administration (MSHA) issued Program Information Bulletin P09-03in April of 2008, providing formal guidance on using programs that model the redistribution of stress during underground mining of coal. A key part of this guidance is visual observation and mapping of ground conditions. If a correlation between ground conditions and model output can be established, the model is considered to be verified, and can be used to guide mine design in similar ground. A simple scale is recommended for ranking observed roof, rib, and floor conditions. This paper discusses optimization and implementation of a ground condition rating scheme in the gateroads of a deep underground longwall coal mine. Roughly 80% of each gateroad length deteriorated in a fairly uniform manner. However, this manner varied between gateroads, as did pillar size. The implementation of a ground condition mapping program, similar to that recommended in PIB 09-03, was successful in characterizing the ground response to mining in gateroads of a longwall coal mine.

Jan 1, 2012

By A G. Mitchell

Stream sediment geochemical analyses were collated from open-file mining company reports and assembled in the REGCHEM computerised database at the Institute of Geological and Nuclear Sciences Limited. The database operates on an IBM-compatible PC microcomputer using an application programmed in dBASE IV and termed GEOEXPL. By August 1992, data for 6383 stream sediment samples from 6335 different sites in the Coromandel Peninsula region (Hauraki Goldfield) were entered, giving a total of 29 292 separate elemental analyses. Preliminary statistical analysis using PROBPLOT on a set of data collected by AMOCO from the Mahakirau-Whangapoua area shows that these data are a complex mix of subpopulations related to mineralisation and different source rock types. Thresholds of 37 ppm copper, 31 ppm lead, 112 ppm zinc, and 2.3 ppm molybdenum, defmed by arithmetic models for the combined data set, separate the individual element sets into 'first order anomalous/lesser anomalous and background' subpopulations as follows: copper five per cent/95 per cent, lead five per cent/95 per cent, zinc one per cent/99 per cent, and molybdenum 15 per cent/85 per cent.

Jan 1, 1992

By David E. Nicholas, Steven R. Dismuke, Paul F. Cicchini

The Buick mine, located 195 kilometers (120 miles) southwest of St. Louis in the Viburnum Trend, is owned and operated by Homestake Mining Company. The mine produces lead and zinc ore from a room and pillar mining method at a depth of approximately 335 m (1 100 ft). The Buick orebody typically averages 60 to 120 m (200 to 400 ft) in width with ore thicknesses ranging from 2.4 to 36.6 m (8 to 120 ft). The mine is divided in two; the halves are referred to as the North mine and South mine orebodies. The North mine orebody contains the higher grade ore; however, the developed reserves for the South mine orebody comprise about 60 percent of the total developed reserves for the Buick property. Existing pillars represent one-third of the total developed reserves.

Jan 1, 1986

By Joseph Daly

An investigation into inaccurate scatter of pyrotechnic detonators led to the innovation of utilising existing (every day) equipment in a manner to accurately determine the true scatter of detonators. This can then be utilised to determine the accuracy of a particular batch of detonators.

Jan 1, 2014

By S. Gorzalczynski

The recent trend in underground mine developments is “bigger is better.” This is most certainly evident in the mine shaft and conveyances that operate within its compartments. Today, there are several new installations requiring mine cages that can transport up to 170 passengers. The technology in mine hoisting is advancing to address a combination of higher capacity requirements, deeper hoisting depths and faster winding rates, however, some areas of the hoist plant have not changed in the past 50 years. The most notable of these areas is the shaft compartment guide string and the conveyance mounted safety arrest mechanism. The technology in use today for the protection of passengers in a shaft conveyance from a hoist rope severance incident remains conceptually unchanged from Elisha Otis’ design of 1850. The actual retardation components, the safety dogs, have taken on several forms since Elisha’s invention with the last major design change occurring in the late 1940s. The arrest of a free falling shaft conveyance requires that the shaft guides withstand the energy imparted on them by the safety dogs. There are some very real limitations presented by the use of wood for this application. The new hoisting era will most certainly continue to demand larger capacity equipment, but also an increased awareness toward safety

Jan 1, 2002

Inhibition of Bubble Coalescence by Salts and Sugars

Sep 13, 2010

By J. Dean Warner

From 1984 through 1987, the Bureau of Mines investigated numerous prospects and new discoveries of columbium, rare-earth elements (REE), uranium, zirconium, and other metals associated with the multi-phased peralkaline granite at Bokan Mountain, southeastern Alaska. This report summarizes the mineral evaluations and estimates indicated and inferred resources for those prospects containing significant tonnage and grade. A total of approximately 96.2 MM lb Cb205 (43 pct of the tonnage at a grade exceeding 0.125 pct Cb205), and 11.8 MM lb U308, 27.9 MM lb Th02, 133.0 MM lb Y203, 637.6 MM lb ZrO2, and 241 MM lb REO are estimated to be contained within nine deposits totalling 37.8 million tons (at least 80 pct of resource tonnage also exceeds 0.5 pct Y203 + REO). Generally, half of the REO content is composed of the heavy yttrium subgroup. Several deposits also contain beryllium and tantalum; 2.1 MM lb of Ta205 and 8.9 MM lbs of BeO were estimated. These estimates would likely be substantially increased with additional exploration. Four deposit types were investigated; shear zones and fracture-related deposits, pegmatites, mineralized dikes, and placers. Mineralized dikes contain most of the beryllium, columbium, tantalum, yttrium, zirconium, and REE resources, whereas shear zones and fracture-related deposits (Ross-Adams mine) contain the principal of the uranium resource. Pegmatites are similarly mineralized as are dike deposits, and contain low levels of gold. Placer potential is suggested, but no deposits were found.

Jan 1, 2011

By Q. Wu

Neural network methodology is used to predict mean particle size resulting from rock blast fragmentation. A blast data base developed in a previous study is used in the current study. A part of this blast data was used to train a single-hidden layer back propagation neural network model for each of the similarity groups obtained in the same previous study. Levenberg-Marquardt algorithm provided the most stable and efficient training out of the four algorithms evaluated. An extensive analysis was performed using a part of the blast data to estimate the optimum number of units for the hidden layer for each similarity group. The remaining blast data are used to validate the trained neural network models. Capability of the developed neural network models is determined by comparing predictions with measured values and predictions based on one of the most applied fragmentation prediction models appearing in the blasting literature. Prediction capability of the neural network models was found to be strong and better than the existing most applied model. Diversity of the blasts data used is one of the most important aspects of the developed models. The developed neural network models are suitable for practical use at mines.

Jan 1, 2011

By R. Gallinger, B. Kelley

"In 1997, a group of Canadian mining companies met to review the Mine Environment Neutral Drainage (MEND) program and to consider future activities. They concluded that (1) that Canadian industry and Natural Resources Canada (NRCan) should fund a small secretariat in Ottawa to support technology transfer in Canada and, (2) that it was important for industry to continue the momentum of MEND on an international scale.The need for the International Network for Acid Prevention (INAP) was strongly endorsed by consultants, company, university, and government experts from Australia, Canada, and the United States who convened in Vancouver in February 1998. The initial focus was the development of a solid knowledge base covering the collective experience of INAP’s members to promote the dissemination of successful practices, the identification of knowledge gaps, and the formulation of effective research proposals. The sharing of information on past successes and failures alone was viewed assufficient justification for the formation of INAP.INAP was officially launched in October 1998, and is now an effective, industry-based initiative to globally coordinate research and development in the management of sulphide mine waste. Significant improvements in the management of sulphidic mine materials through knowledge sharing, research, and development of technology by INAP will reduce liability associated with acid drainage.This paper will explore the international efforts and activities of INAP."

Jan 1, 2005

By R. J. Hickson

From 1993 through 1999 Cyprus Amax Minerals Company successfully completed eight major construction projects around the world. Six greenfield mines were brought into production, an ongoing operation was completely modernized, and an environmental issue was appropriately remediated. The projects stretched over three continents, from arctic Russia to the Atacama Desert, from 16,000feet to sea level, from city suburbs to remote wilderness, from a low of $130 million to over $1 billion. Open pit and underground; mill and leach; gold, copper, molybdenum, and coal were all encompassed. The breadth of diversity experience from these projects inspired Cyprus Amax to create a “best practices” project management protocol, to steer corporate expansion into the next millenium. This paper summarizes those best practices, while high-lighting project management pitfalls to avoid.

Jan 1, 2000

By D. Waite

The Chairman opened the session by wondering why so few papers on Maritime Structures had been received for this conference. Perhaps because the marine environment is so hostile and the access so difficult that engineers tend to be more prudent about new ideas and designs. Dennis Waite noted the number of grey hairs in the room - grey hairs which could be equated with experience gained the hard way. He hoped that this experience would be passed on in the discussion period of this session. The Chairman was delighted to welcome two authors from China, Mr Sun and Mr Liang. He was most grateful on behalf of the conference for their efforts both in preparing their papers and for being able to present them. He regretted that Messrs Noce and Fedolino were not able to present their paper and then welcomed Mr Christensen from Denmark who would present the first paper.

Jan 1, 1991