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By H. A. Bedworth

AlloTs of copper and silicon have been known for one hundred years or more but the commercial development of this type of alloy has taken place during the past few years. In 1905, Sperry l proposed the use of copper-silicon alloys for springs and other purposes for which copper-tin bronzes were used. Some attention was given to this proposal at the time but no one succeeded in producing a practical alloy containing more than a fraction of a per cent. of silicon. The equilibrium relations of the copper-silicon system were studied first by Rudolfi2 and later by Sanfourche 3 and Corson. 4 The constitution of the system has also been recently investigated by Matuyama, 5 and in the laboratories of the American Brass Co. by Smith. 6 Some of the physical properties of the copper-silicon alloys have been investigated by Norbury7 and by Geiss and Van Liempt.8 Summarizing the results of various investigators of the constitution of copper-silicon alloys, the solubility reaches its maximium value, 6.7 per cent. silicon, between 721" and '782" C. At 852" (1. the solubility is 5.25 per cent., while at 400" C. it is only 4.1 per cent. silicon. The copper-silicon alloy begins to get so hard at about 3 per cent, silicon that it is difficult to manage. It was found by Jacobs that the addition of manganese to this alloy considerably improved the working

Jan 1, 1929

Since its inception in 1962, the Julius Kruttschnitt Mineral Research Centre has adopted the view that an effective method of training highly qualified engineers for the mineral industry is the pursuit of postgraduate research programmes conducted in operations, that is, in the mines and processing plants of the industry which the research serves. The paper describes how this is achieved in practice, at little or no cost to the taxpayer, and explores the strengths and weaknesses of this approach in the context of a dual mission for the Centre: 1. The postgraduate training of engineers for the mineral industry. 2. The production of useful R &I) for the mineral industry. Topics discussed include financing, relationships with industry and Government, the maintenance of academic excellence, research style, the marketing of research, and limits to growth.

Jan 1, 1989

Close spatial relationships between the deposits of the Etheridge Goldfield (23 000 kg of bullion) and various regional geological and geophysical features suggest that genesis of the ore deposits was a multi-stage process that started with magmatic and metamorphic stages in the mid-Proterozoic, climaxed with structural and hydrothermal stages in the late Palaeozoic and terminated with an oxidation enrichment stage in the Cainozoic. Acceptance of this hypothesis permits classification of the Georgetown region into areas likely to contain deposits of the Etheridge type and those unlikely to do so. Consequently there is little scope for the discovery of extensions of this field. However, the stratigraphic interval between the source rocks of the Etheridge field and stratigraphically bigger host rocks of the Croydon field may contain disseminated replacement gold deposits of the Carlin type. The potential host (pyritic carbonaceous and locally dolomitic siltstone of the Candlow Formation) is locally faulted and cut by granitoids and the extension of a mineralised, long-standing zone of structural weakness.

Jan 1, 1980

By Wadaw Cybulski

The problem of coal dust explosions: Basic information about the explicability of coal dust: Main parameters of the explosibility of coal dust; Main parameters of the explosibility of coal dust; Limit explosibility of coal dust and its dependence upon the basic parameters: The effect of the initiator of the explosion-on-the explosibility of coal dust: The dependence of the course of an explosion upon the distribution of coal dust in the workings, upon the dimensions of the workings, the length of zones, the direction of the development of explosions and upon the content of firedamp in the air of the workings; Con-sequences of coal dust explosions; The ways of suppressing the danger of coal dust explosions; Stopping the developed coal dust explosions; The explosibility and explosions of lignite dust of xylite structure

Jan 1, 1975

By Iman G. Ghanad

El presente texto describe un nuevo método para el tratamiento de concentrados de cobre con alto contenido de arsénico utilizando el carbón activado como catalizador. Para ello, se realizaron pruebas de lixiviación con concentrados de enargita de tres minas de Chile, Perú y Estados Unidos, donde los resultados señalaron que la disolución de la enargita fue más rápido con la influencia del carbón en la solución lixiviante, incluso después de haber reciclado el carbón.

Sep 12, 2011

By D. Kachongo, Y. Cheng, A. Kashala, D. Samal, G. Mitshabu

Many copper processing flowsheets in the Democratic Republic of Congo include the leaching of oxide ores containing copper and cobalt, copper solvent extraction, copper electrowinning, and precipitation of cobalt salt. Recently, cobalt price gained momentum, driven mostly by the fast-growing electric vehicles battery market. The ore blending scenarios tend to prioritise high cobalt grade ore, whatever the content of copper and other impurities. Therefore, many copper solvent extraction circuits are running below design capacity. The variability of feed induces a variability of the leach solution with respect to copper, manganese, and silica contents. It is thus important to adjust hydrodynamic and metallurgical parameters of the solvent extraction plant to optimise metallurgical performance, production cost, and the quality of the copper electrolyte. This paper presents some results on how solvent extraction plant parameters have been managed in two solvent extraction plants running with lower than designed copper input. INTRODUCTION Referring to a report of the chamber of commerce of the Democratic Republic of Congo (DRC) the online publication Agence Ecofin (2019) indicated that the DRC ranks in the fifth position of the world top copper producing countries with over 1.2 million tons produced in 2018. The same year, 66% of the world’s cobalt was produced in the DRC at over 106,000 tons. If the political situation remained stable and the new tax regime introduced in 2018 did not deter private investors, copper production could reach 1.4 million tons/a in 2020 as pointed out in Mining.com (2019). Forecast figures for DRC cobalt production vary widely depending on analysts. The DRC online magazine Actualité.cd (2018) referring to a ministerial source forecasts over 141,000 t cobalt/a for 2020. The reality will depend on many factors, including the selling price, the supply compared to the demand, and finally the reaction of investors to the new DRC tax regime. The growing electric vehicle batteries market has been the major key driver of the price of cobalt. The five years historical cobalt price graph in figure 1 from infomine.com (2019) shows that the price of cobalt peaked at over 40 USD/lb in the first quarter of 2018. Cited by the online Magazine Creamer Media, Smith (2019) has indicated that the long-term demand of cobalt will likely remain strong.

Jan 1, 2019

By Jacek Paraszczak

For mining companies facing strong international competition and unfavorable commodities? prices, automation of underground operations has got a potential to increase productivity and help cut cost. However, despite considerable technological progress in this field, there still remain some problems to overcome. Furthermore, a success implementation of automation depends also on numerous operational, organizational and even human factors. In this context, this paper reviews briefly a technological progress with regard to different underground operations. Following that, several issues related to implementation of automated equipment and systems are presented and discussed. Particular emphasis is put on the factors whose importance is sometimes underestimated. Some recommendations in this respect are also given. It is stated that a success of an automation project is a function of many ?winning conditions?, which may be created through a very thorough planning and preparation. It is also underlined that despite achievements made, a vision of a man-less underground mine is not yet a question of near future as it may seem.

May 1, 2001

By Aly M. Mohammad

The Delaware River Tramway will link civic and retail developments in Philadelphia, Pennsylvania and Camden, New Jersey. Twin 300-foot towers will anchor the cables at either side of the river. Four high capacity drilled shafts designed by the Geotechnical Department of DMJM+HARRIS support each of the towers. At the Philadelphia tower, each 6-foot diameter shaft extends 130 feet deep and terminates with a 30-foot rock socket. The shafts are situated within the footprint of an existing relieving platform, which complicates the typical construction sequence. Also, the subsurface conditions at the site provide a unique challenge in both the design and construction of the drilled shafts. During the construction of the four-drilled shafts for the Philadelphia tower, a 6000-ton Osterberg load test was performed on the first shaft to verify design assumption and confirm the shaft capacity. The results of the test were utilized to establish load transfer characteristics and develop foundation design parameters suitable for the site conditions. By doing so the Design Engineer was able to reduce the length of the rock sockets on the remaining production shafts by approximately 5 feet per shaft. As a result, the test provided a significant cost saving to the Owner by eliminating 15 feet of rock drilling from the construction costs. This paper presents a description of the unique design and construction methods adopted for the foundations, also on the Osterberg load test including equipment used, number and locations of strain gages, and interpretation of results. The results and findings presented in this paper could benefit both the design and construction industries because it provides a comparison between geotechnical design assumption and actual field measurements; which has always been a challenge particularly for rock formation.

Jan 1, 2002

This paper considers the application of recent laboratory gas sorption data to the understanding outburst phenomena in underground coal mining. Previous use of threshold limits based on gas content and coal rank are placed in perspective. Although this work focuses on overseas research and experience, parallels can be drawn for New Zealand coal settings, taking into account localised mining and geological factors.

Jan 1, 1994

IN concentrating mills, where several millerals are recovered for realisation in more than one product, various systems are used to express the relative economic value of the work done, and, in the hope that it may prove of use to other operators, the writer will describe a system which, in his opinion, is more complete than any other that he has seen published.The controlling factor in all mill work must be based on the economic result represented by the greatest margin possible between the realizable value of the products and the cost of obtaining same.From a mill-man's point of view these are affected by the following factors:1. Metal contents of ore.2. Grade of products.3. Recoveries.4. Working costs.The grade of ore milled is usually outside the mill-man's control, but this may exercise a considerable influence on the grade of his products, metal recoveries, and revenue per ton of ore. Higher grades or recoveries may be obtained by using a more expensive process, or by additional grinding or reagents, and the economic comparison can only be arrived at by obtaining an analysis showing the monetary value of each variation within the possible limits.In the system to be described, the value of unit variations of metal contents of the ore, grade of products and recoveries are calculated in terms of a monetary unit per ton of ore with the returning charges ruling, and any suitable metal prices. To do this it is necessary to assume what, for convenience, is termed a "standard" set of results from the mill, preferably representing about average conditions, and having calculated the effect of unit...

Jan 1, 1931

By J. E. Carrasco, J. D. Stinnette, R. A. Alvarez

"Chuquicamata Underground Mine is one of the main projects for the Chilean government copper company (CODELCO). Underground mine project has been under construction since 2013 and presents a solution for the lower production levels of the open pit and prolongs the life of the mine for the next 40 years. Currently, around 2000 workers operate in the mine daily. Dozens of trucks and heavy machines drives through all main routes and access in the mine. As a mine under construction not all the infrastructure necessary to operate safely in the mine has been completed. Risk of a truck or fixed facility fire is always a challenge to keep under control. One important part of fire simulation relays on what we can do prevent a fire and what can be done with the existing infrastructure to control a declared fire and start evacuation plans. This study has been made as a feasible emergency plan to implement, in this case, of a mine under construction, were limited resources are available. Several fire scenarios have been made to support all the emergency plan strategy and a detailed step by step procedure indicates what the elements of a fire emergency plan and risk analysis are.INTRODUCTIONThe main objective of this study is to describe the importance of fire risk analyses (FRAs) and different methods to be used before commencing fire simulation and methodology steps utilized for a fire emergency plan strategy (EPS) at the Chuquicamata underground mine. It also describes how to classify zones which are going to be affected by fumes and gases propagation derived from the exact location of a fire event. Fire simulation study is helpful to determine the impact on a ventilation system with the main purpose of providing relevant information to complement emergency plans and stablished control techniques in ventilation design and its operation. Most fire simulation studies only concentrates in simulation techniques on itself. But what is the next following step in developing an emergency plan? How can we evaluate, classify and treat risky areas? This study is focused mainly in the phases before and after a fire simulation process. Phases corresponds to a good FRA and how output data can be used for an EPS."

Jan 1, 2019

By M. J. Ramos

Without an exclusive definition of administration in business, we could propose to define it as performance by management to adopt or implement established business formulas. Administration could also be defined as a universal process that organizes people, and achieves, through efficiency, common objectives and goals. Humanity developed some form of this process from the beginning of civilization. To imply that something is new in administration might be considered specious or naïve. Moreover, what is new in management? Administration of business is not new to the world. To prove this statement, we need only ask this question: Does the architecture and monumental workmanship of the past civilizations of ancient Egypt, Rome, and the Incas demonstrate management without administration and without definition of objectives? The answer must be a resounding ?NO!? In spite of this acknowledgment and for the purposes of this presentation, I will use the word ?new? in business and hope that the reader will follow my reasoning. The mining industry has unique characteristics in respect to other industries. It is multi-disciplinary, has a single purpose (majority for one metal), has two players (man and nature), and it involves high risks for generating environmental imbalance. Mining exploits non-renewable and finite resources, creates an unstable job market (work hard to have no work) and a speculative economic market with unpredictable prices ? a one-time payment for a finite resource with multiple recycling. On top of all that, the industry still operates within obsolete petroleum-based technology, utilizing practices that were designed two centuries ago. Today, we confront the challenges of the millennium with outmoded practices and management. Ordinarily, several styles of administration are standardized into a FRAGMENTED vertical system of organization. Mining has rigid objectives in production, with profitability as the focus from the beginning to the end. Citing the concept of safety, as an important facet of production is bombastic since, in truth, mining is an experimental industry that consistently reports high numbers of fatal accidents. In mining, we designed a process to work according to our objectives, demanding attention and supervision of all levels of management with a halo of parameters that are not assimilated into the design. We continue to perform a rigid style of management in an industry that is still not responsive to variations of the market ? losses in particular. The existing design process generates loss without capitalization and without response to said loss. This perception is reflected in a mindset that is only too ready to ignore mining liabilities. The reality of the enterprise has created an immense pressure from top to bottom in the hierarchy to do more with less. It is for all of these reasons that I propose to set forth a new essence for administration that encompasses an alternative vision and style in mining: Management by Loss. MANAGEMENT BY LOSS Management by Loss (MBL) is a systematic, integral process organized to quality control operation and the human profitability within the industry. It permits focus on achievable goals by utilizing the best practices (Mining Open-closing). Identification and characterization of loss in the process determine how objectives are defined, controlling the time limits to execute based on constant balance of mass, energy, water, and ?wastes? in each stage of the industry, in order to reach final objectives. The concept of loss can be defined by various criteria. Generally, it is the mass that could not make or arrive at its destination from a designed process or simply, it could not maintain balance. Otherwise, the design of the process describes the final point of the resource. However, those resources could not make their destination because of failure to use the best design, resources and TIME. The loss has typical characteristics such as Identifiable, classifiable, measurable, manageable, controllable, valuables, negotiable, avoidable, reportable, and monitoring. In the traditional scheme, these losses are not registered; they are made exclusions. We are trapped within a system, which was designed to obtain objectives of the industry in a specific timeframe. In the present style of administration, the focus is total - our emphasis in this treatise is in the loss. The current traditional report form contains only the most positive achievement of objectives, only the best of the exercise, humanizing numbers, without touching what we left behind or what we were waiting for to assimilate as a ?surprise account?(new account of liabilities). Management by loss is a method that redefines the concept of waste (waste zero) for controlling the mine operation under the equilibrium of the ecosystems. This method confronts the problems that impact our industry in this millennium. Understanding and quantifying losses (reserves, resources, time, energy, water, soil, materials, equipment, tasks, labor, ecosystems, etc) is a priority mandate for the industry and demands the application of a ?new ? style of administration by seeking to maintain balance instead of the disequilibrium that mining now creates in nature. It is necessary to answer questions such as: How can we minimize loss? How can the loss be assimilated during the life of the mine? What is the vision of mining in respect to the generation of waste? How can we convert liabilities into assets? In addition, the control of loss is determined in the achievement of the plan. Loss occurs because of a failure of the process in the original plan. Still we do not plan to fail but we fail to plan appropriately. It is a remarkable thing to accomplish and compel those objectives described in the original plan when that plan is designed with a determined budget. If not, we lose time and, of course, capital. Moreover, in Management by Loss (MBL), we can find answers to the following questions: What is the multiplier of productivity in mining? What are the influences of identification and characterization of loss and what is the level of efficiency of energy in order to achieve waste zero (effective cut off grade)? The challenges of mining in this millennium validate this new style of administration. Finally, it is important to point out that mining is entering into an era that has different rules, but the industry is still run by companies functioning with objectives from two centuries ago. They are trying to confront issues with concepts that are not designed for new tasks. Therefore, I ask you to consider this new style of administration of business under a vision of how the industry should be organized and managed, with an attitude of balance toward nature and social responsibility.

Jan 1, 2009

By Marc Ruest, Lewis Martin

A new instrumented cable bolt has been developed by the National Institute for Occupational Safety and Health at the Spokane Research Laboratory in Spokane, WA. Although various instruments are available to measure load distribution and magnitude along a grouted cable, this instrument is innovative in that it uses strain gauges internal to the cable as load-measuring sensors. The instrument has been successfully tested in the field at FMC’s Granger Mine, Meikle Mine, and Getchell Mine. A “split-pipe” laboratory pull test was performed on each of three cable bolts instrumented with the new device. Each test consisted of grouting a 1.83-m-long cable in two 0.91-m-long sections of schedule 80 pipe. A numerical analysis was then performed in which laboratory boundary conditions were simulated and model properties derived from textbook guidelines. The loads calculated by the model were then compared to the measured loads.

By Marc Ruest

A new instrumented cable bolt has been developed by the National Institute for Occupational Safety and Health at the Spokane Research Laboratory in Spokane, WA. Although various instruments are available to measure load distribution and magnitude along a grouted cable, this instrument is innovative in that it uses strain gauges internal to the cable as load-measuring sensors. The instrument has been successfully tested in the field at FMC?s Granger Mine, Meikle Mine, and Getchell Mine. A ?split-pipe? laboratory pull test was performed on each of three cable bolts instrumented with the new device. Each test consisted of grouting a 1.83-m-long cable in two 0.91-m-long sections of schedule 80 pipe. A numerical analysis was then performed in which laboratory boundary conditions were simulated and model properties derived from textbook guidelines. The loads calculated by the model were then compared to the measured loads.

May 1, 2002

By Robert H. Ridgway

This circular outlines salient facts regarding the pyrites industry of the United States and the world. It is founded chiefly upon published information available in the literature of the subject. The United States Bureau of Mines has in its files additional and more detailed data upon many of the subjects presented very briefly here, and will endeavor to assist the mineral industries and the public by giving further information in response to individual inquiries. The bureau will welcome comments, criticisms, and contribu- tions of data that may assist in making later editions of this circular of information more accurate, or may aid in developing more fully the files pertaining to pyrites.

Sep 1, 1931

By G. W. Jones

From evidence made available during the investigation, it was concluded that the first of a series of explosions occurred at 1:15 to 1:20 p.m. September 21, 1951, in an underground vault that housed pressure regulators on the gas-distribution lines that served Brighten. This explosion damaged the pressure regulators and permitted high-pressure gas to enter the distributing mains and individual-service lines. As a part of the gas-distribution system was not provided with means for protection against such excessive pressures, gas gained access to the interiors of many residences in this area and caused a series of disastrous explosions and fires, which took place during a period of approximately 2 hours after the initial explosion in the pressure-regulator vault. Two persons were killed in the first explosion in a residence, and a third person died of a heart attack attributed to the excitement that prevailed during the explosions and fires, Twenty-three persons were listed as injured. Forty-one residences were either destroyed or damaged - 11 by explosion and the remainder by fires, which developed as a result of gas leakage into residences. Fifteen residences were listed as "completely down" or "gutted." Unofficial estimates of property damage ranged from $1,000,000 to $1,500,000. In view of observations made and information obtained during the investigation, recommendations are presented in this report relative to the natural-gas distribution system in Brighton, which may be helpful in the prevention of similar accidents in this and other communities.

Jan 1, 1952

By Nikhil Dhawan, Shrey Agrawal, Veeranjaneyulu Rayapudi

India’s steel vision of 2030 requires a huge amount of quality iron ore. The utilization of low-grade iron ores such as banded iron ores will play an important role to achieve the same production. The absence of alumina impurities in the banded hematite jasper (BHJ) ore provides it an edge over other low-grade iron ores. The conventional beneficiation techniques such as magnetic separation and washing were found to be ineffective to produce suitable feed (Fe ~ 60%) for the blast furnace. It was found that microwave exposure provides significant enrichment to the low-grade iron ore and can be used as a pretreatment step in the beneficiation of similar low-grade iron ores. The above study reveals that hematite phase is susceptible to microwave exposure which enhances the separation of iron values from impurities. Under optimum conditions, an iron-enriched concentrate with 61% Fe, 85% Fe recovery at 50% yield can be achieved from BHJ feed ~ 38% Fe. The pretreatment process for BHJ beneficiation includes only microwave exposure without any chemical additive and may prove economical and industrially feasible.

By R N. Humphries, R J. K Thompson

Large-scale coal mining in South Wales dates back to the late 18th and early 19th centuries with the birth of ironmaking on an industrial scale. This rapidly gave rise to new and large communities with immigration from far and wide across the United Kingdom (UK). These new communities were largely dependent on coal mining and served as the main form of employment and social cohesion until the industry’s demise in the 1990s. With wholesale mine closure and the concomitant loss of employment, the extensive environmental degradation and chronic mine-related illness left a deep scar on the psyche on many still living in the South Wales mining communities. This coupled with memories of strife in the 1980s has resulted in ongoing hostility toward the surface coal mining of the remaining accessible coal reserves in the proximity of these communities.The purpose of this paper is to set out the historical basis of the concerns of these legacy mining communities in South Wales and explain how they are being positively addressed by both the recently evolved planning and regulation system and by today’s surface mining industry. Reference is made to experience gained from two recent applications for surface coal mining adjacent to former mining communities. Ways are suggested in the approval process that surface mining can work in more harmony with the local communities through working partnerships between the mining company, the authorities and regulators and the affected communities. It is concluded that partnership is key to creating a more responsive mine-operating culture and a means to securing approval for future surface coal-mining prospects in South Wales, and probably elsewhere too.CITATION:Humphries, R N and Thompson, R J K, 2014. Surface mining and legacy mining communities in South Wales, UK, in Proceedings Life-of-Mine 2014 , pp 399–412 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By L. A. Maseko

"As part of the mining engineering curriculum, students are required to be placed in industry for vacation work or work-integrated learning (WIL). In this paper we review work-based placement as done at the four South African mining schools: the University of Johannesburg, the University of Pretoria, the University of the Witwatersrand, and the University of South Africa.Key aspects of past and current WIL (pre- and post-graduation) practices that may need attention are highlighted for consideration by all universities that provide professional qualifications. Work-directed theoretical learning, problem-based learning, project-based learning, workplace learning, and simulated work experiences are discussed as legitimate approaches to WIL.Regardless of the choice each institution makes, commitments of universities, preparedness of university teachers, and the desire for equity and excellence will play an important role in the provision of WIL.DefinitionsAccredited Qualification: a qualification awarded on successful completion of an accredited programme.Advisory Boards (or Committees): are essential infrastructure for a WIL curriculum that is built on the integration of the workplace and the university. This requires the collaboration of experts from both environments. Workplace advisors are critical to the success of the academy as they embody expert knowledge of the ‘real world’.Assessment: the process of determining the capability or competence of an individual against standards by evaluating performance.Category: a mode of registration defined in or under the ECSA Act which has a distinctive purpose, characteristic competencies, defined principal routes to registration, and educational requirements.Experiential learning: (in South Africa sometimes used synonymously with work placement or cooperative education) is a term used with a great variety of meanings in the international literature. More broadly, it may refer to learning that has meaningful learner involvement. It is the process of generating meaning from direct experience. In the international literature, experiential learning is learning through reflection on doing, which is often contrasted with rote or didactic learning."

Dec 1, 2018

By John G. Henning

The Hoyle Pond underground mine is located in the Porcupine Gold Camp, 18 km east of downtown Timmins. Since the initiation of production in 1985, the operation has produced in excess of 1.9 million ounces of gold at a grade of 15 grams per tonne. Currently, Hoyle Pond ranks 8th in total ounce production for all past and present producing mines in the camp, with the highest head grade of any of the significant past, or present producing mines in Timmins. Cut and fill, shrinkage, longhole and panel mining methods are employed to excavate the narrow gold bearing structures. Using illustrative examples, this paper provides an overview of factors, such as geologic setting, rock mechanics challenges and mine infrastructure, which influence mine design at Hoyle Pond.

Oct 1, 2004