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By H J. J Boshoff

Mine closure planning integrated into life-of-mine (LOM) planning during the operational phase consists of many subcategories. One of these subcategories that needs to be fully integrated into the LOM planning is that of water management planning. Issues arise when mine water management infrastructure, which is required post-mine closure, is only considered closer to the end of LOM. Once the mine is closed monitoring is focused on water quality as an indicator of closure performance, hence inadequate upfront post-mining water management planning or integration into operations will result in environmental harm. The lack of considering post-mining water management is not uncommon in LOM planning. Poor mine site water management and planning are a wide reaching problem for the mining industry. Numerous active mines have been issued with environmental notices and penalties for contaminated water discharge; including issues with abandoned mines now being cared for by governments all over the world.Mitigating sources of water contamination caused by existing and closed mine sites that are leaching pollutants might be impractical, due to inaccessibility to the contaminants or final landform topography. The opportunity to consider and introduce post-closure required mine water management infrastructure is lost once the waste facilities are constructed. Mitigating contamination is made more problematic with mines located in remote areas, serviced by dedicated roads, water supply, electrical supply, etc. It is expected that these services will be decommissioned or drastically reduced, once closure is reached making remedial work much harder. Inadequate planning, to ensure access and easily maintainable water management infrastructure, could lead to erosion and contamination going unnoticed. There are numerous examples of poor mine water management practices in Africa, Asia, Australia, South and North America. In the United States more than 23 000 km of streams are affected by pollution sourced from some 50 000 abandoned or mature mine sites (DeGraff, 2007).CITATION:Boshoff, H J J, ?2014. Inadequate water management planning resulting in long-term closure liabilities, in Proceedings Life-of-Mine 2014 , pp 233–246 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By . Adolfo Farfán C

El presente trabajo describe los problemas ocasionados por los incendios en la mina de Cerro de Pasco. Si bien es raro que se origine un incendio en minas de características especiales como la de Cerro de Pasco, no se descarta la posibilidad de un corto circuito o algún otro infortunio. Por ello, es necesario conocer las causas, zonas de vulnerabilidad, los métodos de minado, ventilación, los antecedentes del incendio, origen, combate, las cuadrillas de rescate minero y la prevención de este desastre.

Nov 20, 1978

"El presente estudio describe el proceso de combate contra incendios efectuado por la mina de Cerro de Pasco. Dicho procedimiento incluye una revisión anterior al año 1936 en dos etapas, las técnicas actuales y los planes futuros preventivos sobre incendios. Anteriormente al año 1936, los siniestros ocurrían en los tajos del último tipo y la forma de contrarrestarlos era a través de tapones, aislando la zona de incendio y creando un enfriamiento por medio de chimeneas de ventilación. Sin embargo, esta forma de combate contra los incendios no resultó efectiva, dado que no evitaba completamente el ingreso del aire por medio de los tapones y a su vez, la proliferación de minerales con el tiempo volvía inaccesible la zona. Por tal motivo, la minera solicitó los servicios de un consultor, quien propuso tres sistemas: inundación de la zona del incendio, sofocación del incendiopor medio de anhdriddo carbónico y el sistema Plenum. De los tres sistemas, se consideró a este último pues mantenía la zona de incendio bajo presión de aire y no alteraba el resto de la zona de trabajo. Posteriormente se sugirió el uso del sistema ""Slimming"" o relleno de lodos, los cuales cubrían hidraúlicamente los espacios vacíos alrededor del incendio con un material inerte, adquierendo la forma de un fluído. La efectividad del método era suficiente que fue adoptada a partir de 1938 hasta el presente. Entre los procedimientos actuales se propuso el reemplazo del pino de oregón por la madera de eucalipto por su costo y composición menos inflamable. Asimismo el entablado del piso se sustituyó por una capa de concreto de tres pulgadas de espesor, limpieza del tajeo y equipamiento adecuado de las chimeneas, la ventilación adecuada, el entrenamiento permanente de las seis cuadrillas de combate, construcción de galerías y cruceros auxiliares de transporte, el relleno por lodo y el uso del sistema de alarma denominado ""Stench Mercaptan"", que se inyecta en las tuberías de aire comprimido y sistema telefónico. "

Jul 20, 1957

By Fred H. Lippold, Wm. H. Wolf

Methods of fair payment for excavating, supporting, and concrete lining tunnels have been sought by various owners for years. Tunneling techniques have changed with the development of equipment-from the hand-mucking operation to the machine mucker and, most recently, to machine-boring; from tunnel supports using timber sets to steel sets to rock bolts and, most recently, to shotcrete support; and from hand-placing the concrete lining using wooden forms to pumping or pneumatic placing using steel forms. As tunnel construction techniques advanced, so did methods for payment for the work performed. The recent development of tunnel-boring machines, or "moles," is precipitating another change. These changes have led to some difficulty in providing proper payment for the various items of work for different types of tunnels. As a major construction agency engaged in water-resources development in the western states, the U.S. Bureau of Reclamation has long been aware of the need for clarification of payment provisions in tunnel construction. The Bureau has some 150 miles of tunnels completed on its projects and about 50 miles of tunnels under construction. In this construction, the Bureau has benefited by the advance made by contractors in improving the techniques of tunnel excavation. To assure that the Bureau has an up-to-date approach to payment provisions, the Chief Engineer recently established a "standard" method of payment for all types of tunnels. It is believed that this new method of payment will be equitable for all contractors bidding on various types of tunnels using the diversity of methods of excavation now available to them. These payment provisions provide for different quantities for excavated tunnels using the blasting technique or using machine-boring techniques. In this way, the contractors have a choice in excavation methods and an equal opportunity to be low in their bids. We believe this will be an incentive to all contractors to be as progressive as the development of new equipment economically allows.

Jan 1, 1970

By James L. McGregor

St. Joseph Lead Company has been paying incentive bonuses for well over 40 years. In 1958 almost half of St. Joe's 1,860 employees in Southeast Missouri received some form of incentive bonus in addition to their guaranteed wages. There are very few payroll jobs in St. Joe s Southeast Missouri organization that lend themselves to a reasonably good measurement of production or quality, or both, where an incentive bonus is not paid. The term "Incentive Bonus" is used to differentiate betwen bonuses that are based on quantity or quality of work, and those that are merely additional pay of a standard amount per hour or day because of an employee being temporarily assigned to some unusual task, An employee temporarily assigned to a job where the working conditions make the job performance unusually difficult or where a special skill is used is often given a bonus of some standard amount per hour or shift in addition to his usual rate. This is merely a convenient way of paying something extra without disturbing the normal rate structure. Actually, it is differential pay similar to that almost universally paid for evening and night shift work. Bonuses of that type are not being considered in this paper. The basic reason or theory for paying incentive bonuses 9s to get improved production at lower cost, Unfortunately, it is often difficult, if not impossible, to find a yardstick by which it can be definitely proved that a particular bonus plan is accomplishing its purpose, It becomes, then, a matter of judgment on the part of management personnel as to the value of the bonus plan. The fact that St. Joe Lead Company has continued to pay bonuses for over 40 yews and has increased the number of bonus schedules used attests to a definite belief that they are beneficial to the company's successful operations.

Jan 1, 1960

By Joel K. Waterland

The Homestake Mining Company at Lead, South Dakota is one of the few remaining gold properties still in operation, in this country. The mine is relatively deep, with a bottom production level of 4250 feet, and a bottom development of 6200 feet. 4, 800 tons of ore are produced daily from three rather large, but inconsistent ore bodies; the dip of which is easterly at about 72 degrees, and the plunge to the south is about 30 degrees. The ore is, for the most part, a chlorite schist with large veins of secondary quartz and cummingtonite schist The ore is not continuous in any direction, but is localized at the ridges of the very intricate system of anti clinal folds. This property has been in active production since its establishment in 1876, except for a period during World War II. The incentive, or contract pay system, has been a gradual process that has been developed by the trial-and-error method down through the years. In looking over the old records, hand-shoveling was paid on an incentive basis as far back as 1916. Since this time, the contract system has grown until it now includes almost all types of underground work - except haulage and maintenance work

Jan 1, 1960

Methane is present in varying degrees in nearly all underground coal mining operations. At mixtures with air near 5-15% it is explosive and consequently since it is not usual for these levels of contamination to be reached in the general body of a mine ventilation system it is not unusual to experience it in specific places. On longwall faces the most used power loader is the shearer machine and because of its general shape, situation and operation it is likely that all the factors which are required to cause a frictional ignition can be present. This paper makes a general appreciation of the causes of these ignitions and methods which are and have been used to control these situations on and around these machines.

Jan 1, 1981

By Frank R. Field, Randolph E. Kirchain, Elisa Alonso

"There are a number of environmental incentives for increasing recycling, including the reduction of waste, energy and resource use. Recycling can also be advantageous for manufacturing firms in both the short and long term. Secondary material can substitute for primary material, potentially dampening primary material price increases and reducing the pressure for greater primary extraction. This paper examines the potential for and dynamics of recycling for the case of platinum using a dynamic, behavioral simulation model of the primary and secondary markets. Since the secondary supply of platinum depends on a supply chain separate from primary extraction, recycling can diversify the risks of primary supply instabilities. Over time, recycling can cut primary consumption, reduce overall costs to firms, and possibly reduce the impact of price fluctuations upon firms.IntroductionThe benefits of recycling, from the perspective of the environment, are many, and the environmental benefits of increased recycling are considered a step towards increased sustainability [1, 2]. Life cycle assessments indicate that obtaining materials from secondary sources generally requires less energy and has fewer environmental impacts than extraction and refining of primary materials [3]. Analyses of materials flows show that, in addition to landfill volume reduction, recycling reduces primary material consumption, affecting long term materials scarcity [4, 5].The benefits of recycling are not limited to the environmental. Firms can benefit from the lower energy costs of recycling, especially that of metals whose primary extraction and refining are particularly energy-intensive (e.g., aluminum). The routine participation by firms in secondary materials markets (e.g., www.recycle.net) shows that this advantage has not gone unnoticed.Recycling can also benefit firms whose costs can be significantly affected by changes in material prices resulting from material shortages and material scarcity, with potentially permanent effects upon firms [6-8]. This paper focuses on the impact of recycling in the face of platinum scarcity for supply chain downstream firms."

Jan 1, 2008

By Donald B. Gillies

The fundamentals of human nature don't change much from generation to generation, or even from century to century. Except for the spur of necessity and the lure of reward and ad venture, few of us would bestir ourselves unduly. The general welfare has little appeal to the average individual. Its promotion comes about mainly as a by-product to individual efforts directed at more personal benefits and satisfactions. In discussing incentives for the mining industry, we really are talking about incentives for people who devote their energies and resources to mining. The vigorous and productive mining industry as we have known it was the product of the varied incentives we have known in the past: the lure of great financial reward if you struck it rich; the thrill of romance and adventure in the search for mineral wealth, usually along the frontiers 'of civilization; the satisfaction of developing a great, productive enterprise by the application of skill, courage, and determination in the face of obstacles. Back of the prospector and engineer were other venturesome persons willing to take a flyer with their savings in a grubstake, or in stock in a promising mining venture, hoping for large returns, but reconciled to take a loss and try again with the next opportunity. It is free enterprise-a chance for high profits, but a chance also of total loss-that created the great mining industry of this country and of the world. Free enterprise has given us, in the United States, the greatest productive system in the world, the highest standard of living, the most abundant life. The lure of gold-whether from the ground or merely incidental to the discovery and development of our mineral resources-pushed our frontiers westward across the country and northward into Canada and Alaska far in advance of the staid course of agriculture and commerce. No one guaranteed success to our forebears as they risked life and fortune in developing a new country. Self-reliance was the backbone of our economic and spiritual Progress and achievements. Our neighbors had little time to spare from their own problems. And though there was a willingness among the pioneers to help one another, they didn't lean too much on one another.

Jan 5, 1950

By Ricardo Boullosa

El presente trabajo describe el sistema de bonificación como método de incremento de producción en el personal de la minería. El diseño de estos sistemas beneficia al trabajador y a la empresa, así como permite obtener ganancias sobre la base propuesta. Entre los sistemas de incentivos más conocidos figura el sistema de Halsey, Rowan y Barth. Asimismo, tenemos los sistemas en los cuales las ganancias varían en proporción al rendimiento y aquellos con ganancias variables a diferentes niveles de rendimiento como el de Taylor y Merrick. En ese sentido, la administración debe garantizar el apoyo necesario para el avance de incentivos, actualizándolos periódicamente.

Nov 8, 1982

By P M. Black, T Itaya

Arc-type volcanic activity has been a major feature of the late Cenozoic geological evolution of the Pacific-Australian plate boundary in the northernNew Zealand region. The time/space distribution patterns of arc-type rocks reflect changes in the nature of the plate boundary as it has evolved. Inception of volcanism began in the north during earliest Miocene times (26 Ma) following ophiolite emplacement and during the next 10 Ma developed into a volcanic arc segment extending south to the present position of the central North Island. The northern part of the arc became extinct about 15Ma ago, but activity continued in the central (Coromandel) part of the arc until about 5 Ma ago. In late Pliocene and Quaternary times volcanic activity has become concentrated in a northeast trending zone which is collinear with the Tonga-Kermadec Arc.   These time/space patterns can be interpreted in two ways. Firstly, if relative plate motion was essentially transform in the region prior to 26 Ma then a small change in the relative plate vectors may have initiated subduction and the associated volcanism. Southward evolution of the arc can then be seen as the straightening and extension of a single arc. Alternatively, the distribution of volcanic rocks can be interpreted as the capture of a relatively short lived arc by southward migration of the dominant Tonga-Kermadec subduction system.

Jan 1, 1995

By Black PM, Itaya T

Arc-type volcanic activity has been a major feature of the late Cenozoic geological evolution of the Pacific-Australian plate boundary in the northern New Zealand region. The timelspace distribution patterns of arc-type rocks reflect changes in the nature of the plate boundary as it has evolved. Inception of volcanism began in the north during earliest Miocene times (26 Ma) following ophiolite emplacement and during the next 10 Ma developed into a volcanic arc segment extending south to the present position of the central North Island. The northern part of the arc became extinct about 15 Ma ago, but activity continued in the central (Coromandel) part of the arc until about 5 Ma ago. In late Pliocene and Quaternary times volcanic activity has become concentrated in a northeast trending zone which is collinear with the Tonga-Kermadec Arc.

Jan 1, 1995

By Eduardo Christo Saltoratto

Foram realizados tratamentos térmicos de têmpera e revenimento para aumentar a tenacidade do material, aço NM87 designação 1045, uma vez que ele apresentava, no estado inicial, baixa absorção de energia. Com o material mais tenaz foi obtida uma melhor faixa de energia para cálculo das incertezas. Foram feitos corpos de prova com variações nas medidas laterais, de comprimento e profundidade do entalhe e ensaiados na temperatura ambiente para determinação das incertezas do tipo A e B. Com as incertezas determinadas pelos métodos estatísticos e não estatísticos, foram feitos ensaios, variando-se a temperatura, para obter dados de ductilidade (energia absorvida, expansão lateral e percentual de área dúctil) em relação a temperatura e com esses dados determinar-se a temperatura de transição dúctil – frágil e sua incerteza.

Aug 17, 2017

By R. C. W. Webber-Youngman

The mining industry in South Africa faces real challenges with regard to the reduction of safety-related incidents. The purpose of this paper is to highlight the need for alternative interventions in addition to other safety improvement strategies already employed on mines. It furthermore supports an existing paradigm: incident investigations. An investigation into fatalities in the South African mining industry shows that although great progress has been achieved through the reduction in fatalities in all sectors of the industry over the last few years, more can and should be done to achieve status of ?zero harm?. Fatalities and lost time injuries on mines result not only in large financial losses, but also in disruptions of mining operations in general through Section 54 stoppages to resolve the situation. The approach of the paper is therefore not to try and prove whether there is high fatality rate and/or lost time injuries, but in what way incident reconstruction simulations (IRS) can have an impact in the future prevention of such incidents. The challenge therefore lies in the utilization of pro-active systems that would show employees the possible outcomes of being exposed to certain hazards. In real life, these incidents cannot be re-enacted and in most cases we can only learn through the previous mistakes of others. A virtual reality (VR) education and training system will enable employees to be ?exposed? to different hazards in a safe environment, and simulation, in a ?forgiving? environment, of the possible consequences of unsafe acts. According to the Occupational Safety and Health Act (OSHA), unsafe acts and unsafe conditions are indirect causes of safety-related incidents, but there are also direct causes; for example, unplanned release of energy and/or hazardous material, and basic causes, for example, management safety policies, personal factors, and environmental factors. The administrative workload associated with any incident investigation places a large burden on the investigation team, and in most cases other employees are informed through vague administrative processes what the ?real cause? for the incident/accident was. New preventative strategies are often put in place without showing the employees what the real causes of the incident/accident were. This can be mitigated through the use of interactive VR simulations/animations of the hazards that they are exposed to and how to deal with them. If VR interventions are not used as proposed by this paper, the real causes and consequences of almost all fatalities and lost time injuries may never be fully understood. This paper also emphasizes what potential impact IRS could have on the prevention of future mine incidents as part and parcel of a pro-active risk prevention strategy. The intention is therefore not to replace any other risk prevention strategies, but to visually enhance the reality of the incident. Keywords virtual reality, risk management, incident reconstruction simulations, interactive safety training, usability context analysis, mine safety.

Jun 1, 2013

By R. L. Grayson

Evidence has accumulated indicating that cultural change toward safer workplace behaviors is beginning to occur systematically in the coal industry. Through a range of programmatic mining company successes, enforcement and litigative actions, economic responses to competition, and integrated efforts by federal and state agencies, a broader participation of safety and training professionals is being achieved to address prioritized workplace problems at mines. Small steps in workplace-related improvements have been realized already, but the trends in industry safety statistics, coupled with focused programmatic initiatives, indicate that more definitive and systematic steps are occurring to improve safe behavior in the workplace routinely.

Jan 1, 1996

By Teh-Yu Kao, Don J. Wood

With the increasing industrial use of the method of transporting solids by fluids through pipes, a better understanding of the basic mechanics of a solid-liquid pipe flow system is essential. In this study the phenomenon of incipient motion of solid particles resting in a sediment bed on the bottom of a pipe is investigated. Since a system would fail to operate at the designed solid-liquid flow condition if it was not capable of operating through the transient initial flow phase, information concerning the starting transient is of great interest. An objective definition of incipient particle motion, derived from energy considerations, is first proposed. Using this the critical state is defined to describe the flow condition during which a solid particle can at least temporarily escape the sediment bed and move in the liquid. Postulated also in this study is that the condition of incipient motion can be reasonably well predicted by a consideration of particle equilibrium in a direction normal to the pipe axis. The incipient condition is considered to occur at the instant the force between the bed and the particle, normal to the pipe axis, is zero. Experimental measurements of incipient conditions are obtained for water flowing through a horizontal pipe with sand sediment beds of different thickness. These are compared to predicted values with good agreement.

Jan 1, 1975

By J. W. Bolton

PRODUCTION of sound bronze castings is a matter of great practical interest to users and manufacturers of high-grade non-ferrous engineering specialties. Although there has been much excellent research in this field, there still remains some confusion regarding the fundamental principles underlying production of really sound bronze. The literature of the past 20 years on this subject indicates that the prevailing opinion of metallurgists and foundrymen has been that unsoundness in bronze is due generally to oxidation. The following references are typical.

Jan 1, 1929

By Hilde TWC

Synthesis of GLORIA side-scan sonar and other geophysical data has provided morpholo- gical and tectonic details of the interaction between the Nazca and South American plates along the Peru Trench (80S-15¦S). Our analyses suggest that a new propagating rift of the Galapagos type is evolving along the Mendana Fracture Zone (MFZ). Subduction induced rift- ing of the Nazca plate is accompanied by organized seafloor spreading for the last 3 Ma at least. GLORIA sonographs and bathymetric mapping show an 8-10¦ divergence in MFZ width towards the Peru Trench. The fracture zone comprises numerous ridges and troughs and a lack of sediment cover in the axial part. Young magnetic lineations (anomalies 1-2A) are observed within the fracture zone wni.cn are orthogonal to the older Nazca plate lineations. The central anomaly narrows west- ward and can be observed up to 400 km seaward of the trench whereas anomaly 2A is terminated about 200 km from the trench axis. Recent SeaMARC II sonar mapping in the region shows large igneous blocks in the Trench axis to the north of MFZ but absent to the south. We believe these blocks represent young seafloor of MFZ rift/spreading center broken off from the ridges as they subduct along the Peru Trench. The MFZ rift is propagating west- ward at a rate of 115 km/Ma (25 km/Ma relative to the South American plate). Given the present rates of accretion at the East Pacific Rise and of propagation along MFZ rift, the Nazca plate will be divided into two parts in about 35 Ma.

Jan 1, 1987

By D. D. Munro

Finsch Mine is a kimberlite diamond mine located at Lime Acres in the Northern Cape Province of South Africa. The mine was founded in 1961 and started surface mining in 1964. Underground production commenced in 1990 using a modified blast-hole open stoping method for the mining of Blocks 1, 2 and 3. Block 4 is currently being mined as a block cave. The process of identifying and optimizing a method to mine the Block 5 orebody started in 1991, and in 2006 incline caving was identified as being technically feasible. This paper aims to document the process employed in developing this method by the Block 5 prefeasibility team as well as discuss the technical challenges encountered during this process. The paper commences with a history of Finsch Mine and highlights the complex geology and threat of sidewall failure that prompted the decision to use block caving as the mining method for Block 4. A literature study of mines that implemented mining methods upon which the incline cave was conceptualized is then presented. These practices were then used to form the basis for the designs on which the initial geotechnical modelling was done and built upon through an iterative process of modelling and design changes. The ventilation of the mining area, initial productivity simulation results, and the applicability of automation and comminution processes in the incline cave are also presented. The paper concludes with an investigation into some of the challenges of the mining method, and shows that that incline caving is a technical option available for further investigation in determining the optimal mining method to be employed at Block 5, Finsch Diamond Mine. Keywords massive mining, incline caving, geotechnical modelling.

Jul 1, 2013

By W. G. Scott

SINCE devising the incline top-slicing method in use It the Coronado mine,1 I have had numerous inquiries is to how the same system could be adapted to larger orebodies. Based upon our experience here, 1 have outlined below some suggestions for its, application to orebodies of larger size. Modifications and extensions, of course, would have to be made to take care of different dimensions and irregularities. In order that one may have a better understanding of the scheme, a brief description of the Coronado method will he given first.

Jan 11, 1917