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By Henri Letient, Tom Aley, David Evans

Antamina is a large open-pit copper and zinc mine located within the Central Andes of Northern Peru at an altitude of 4300 masl. The facilities are situated within the headwaters of several watersheds, within the Amazon basin. Nearby villages rely heavily on springs and streams for drinking and irrigation water. The principle source of baseflow during the dry season is from Cretaceous karstic limestone aquifers. Antamina will produce nearly 1.4 billion tonnes of waste rock over its mine life. Finding suitable sites for storing large volumes of waste rock is often a challenging task – especially in karstic, alpine terrain. Detailed hydrogeological investigations are essential for delineating the karstic hydrogeologic watersheds associated with the proposed waste facilities, which are often very different than topographic (hydrologic) watersheds. Contamination vulnerability mapping at Antamina consisted of geological and karst mapping, geophysical surveys, geochemical testing, dye-tracer studies, drilling and aquifer testing. Detailed mapping followed by dye-tracer studies proved to be the most cost-effective methods for characterizing the karst aquifer systems. The results were used to optimize waste rock management at the site to minimize potential impacts on groundwater resources.

Jan 1, 2005

By Jerome F. Thomas

The primary purpose of this paper is to review the fire and explosion hazards associated with hydrocarbons heavier than methane. Methane is the classical hydrocarbon encountered in mines whose presence is generally due to bacterial decomposition of organic debris. The higher hydrocarbons are more likely to be found during tunneling when petroleum products either natural or man made are encountered. Fires may be defined as rapid gas phase oxidations accompanied by the rapid evolution of light and heat. Explosions may be defined as uncontrolled fires. The rapidly expanding gases resulting from combustion exceed the speed of sound and generate percussive forces. The essential elements for a fire or explosion are shown on Figure 12: (1) a gas phase explosive mixture and (2) an ignition source. The paper will attempt to review various aspects relative to the explosive mixture; The concentration and composition; Techniques for detection; Techniques for ventilation to reduce concentration below explosive limits. The ignition sources are also listed on Figure 12. An arc originates from an electrical source such as electrical switches, relays and motor brushes. Static electricity can also be an arc source and may be generated by air flowing through rubber bases or a rapidly moving endless belt. A spark is generally associated with abrasion of iron metal. A flame source may be a match, candle. cutting or welding torch, or engine exhaust. If

Jan 1, 1974

By G. F. Revey

All underground operations have limiting factors that influence overall profitability. Hoisting, hauling, available headings, labor, milling capacity and other factors limit how much material can be removed from an underground mine. Consequently, when mines use limited labor to handle the additional rock from overbreak and to perform extra ground support tasks, productive activity is replaced by non-productive work. Mining economics are further penalized when overbreak causes dilution of ore grades. This paper reviews organizational systems that mines have used to create environments which foster the creation of successful overbreak control programs. Actual case histories document the various quality improvement techniques, worker incentives, and practical project management systems used by these mines. A brief review of controlled blasting technology sources and overbreak measurement tools is also included.

Jan 1, 1997

By J. M. Elegante

A belt drive attendant was working underground during his shift at the junction of two belt drives. He worked alone, but communicated with others at the mine by underground phone. At noon his shift foreman stopped by his workstation. At 2:00 p.m. he was contacted by phone by a fellow belt drive attendant. At 5:00 p.m., he was found dead by the oncoming evening shifter.

Jan 1, 1989

By O. M. G. Newman

The Electrolytic Zinc Company of Australasia Ltd., generates a jarosite waste at its Risdon smelter. Since 1974 this waste has been disposed of at sea off south-east Tasmania. As part of a monitoring programme prescribed by the Australian Government, bottom sediments from the disposal zone are monitored regularly. QEM*SEM image analysis complements conventional chemical analysis, having the ability to partition the occurrence of an element between sediment particles of metallurgical and natural origin. The adaptation of QEM*SEM techniques to the evaluation of bottom sediments provides insight into the fate of the particles of jarosite waste.

Jan 1, 1989

By R. K. Singhal

Optimization of a load-haul system for a surface mine involves two processes. The first is proper selection of mining equipment compatible with the minesite job specifications and the second is an efficient utilization of this equipment. All things being equal optimal productivity and cost is achieved when the capacity of the hauling equipment is matched at all times with that of the loading equipment.

Jan 1, 1986

By Dario DeBenedictis

The speaker intends to review the positions expressed by the Owner, Engineer and Contractor representatives, respectively, with emphasis on the legal aspects of the relationships among said parties, and particularly dealing with the preparation and interpretation of specifications generally, and changed conditions clauses particularly, and the handling of claims arising thereunder.

Jan 1, 1997

By D. E. Ranta, George F. Weaton

Estimating the Iron Ore reserves of Minnesota are directly related to both the geology of the deposit and the Scandinavian heritage of its people. The flat lying deposits, when properly prospected, make estimating easy and accurate across wide areas of the Mesabi Range. It also makes taxation simple on the unmined reserves. The reserves are their heritage and all the people should benefit, not just the owners. Heritage also dictates that newly discovered ores were there before discovery, hence, subject to the omitted property tax and liable for six years back taxes.

Jan 1, 1992

By S. E. Clay, P. R. Taylor

A physical model for the diffusion and flow of gases through porous solids, which accounts for the random nature of individual gas molecules moving through a solid of definite structure, has been formulated. The model was solved using' the Monte-Carlo technique. It was then used to evaluate specific constants related to the dusty gas model and to describe the gas-porous solid diffusion phenomena. Experimental results were used to validate the stochastic model.

Jan 1, 1988

By P. E. Sperry, J. M. Duncan

INTRODUCTION The purpose of the report on which this paper is based is (1) to evaluate the potential for cost reduction of urban mass transit tunnels by use of alternative materials transport systems during the tunneling process, and (2) to identify research and development program elements to assure that the materials transport system will not become the limiting factor for the rate of excavation. The approach taken was: Review the state of the art of urban tunneling by extensive interviews with representatives of tunnel contractors, equipment manufacturers, government agencies and consultants, and by review of recent literature.

Jan 1, 1979

By D. M. Larsen, K. R. Gardner, P. B. Altringer

The Bureau of Mines, U.S. Department of the Interior, is conducting batch and small- scale continuous laboratory studies on the biologically assisted removal of selenium from process waste waters. Mixed cultures of gram- negative bacteria isolated from several brackish water marshes are capable of reducing selenate [Se(VI)I to selenite [Se(IV)I and precipitating an amorphous elemental selenium product. Selenium extractions ranged from 80 to 96% regardless of the initial selenium concentration. The conditions for rapid bacterial growth and reactor design for optimal selenium removal have been investigated. The mechanisms of bacterial reduction and the rate of selenium removal for scaleup to larger systems is discussed.

Jan 1, 1989

By Paul Gribbon, Greg Colzani, Jim McDonald

The $300 million West Side Combined Sewer Over?ow Project consists of over5.5 kilometers of soft ground tunnel, an 833-million liter per day (220-MGD) deep shaft pump station, 3 kilometers of micro tunneling, and other miscellaneous shafts and pipelines. The construction contract, underway since September 2002, is a reimbursable cost plus fixed fee contract that included a quali?cations-based contractor procurement process and has undergone some modi?cation since execution. This paper will describe the contractual issues addressed to date, dispute resolution, where improvements can be made, and how an Owner can evaluate whether this type of contract is the best approach for an underground project.

Jan 1, 2005

By Arthur M. Ribe

In my experience, nothing helps me better to get off to a good start in preparing a paper or a talk than a copious consultation with a comprehensive dictionary. I also feel defining the perimeters of a particular subject is helpful to the listener and reader. Sometimes thus precisely defining even the most common of words is helpful. Our general topic this morning as all of you know is "Transportation of Industrial Minerals." The definition of transportation given by the dictionary which I think is appropriate here is: "Systems and modes of conveyance of persons or goods from place to place." Our preceding panelists have outlined for you the state of the art inso¬far as systems and modes of conveyance from place to place are concerned today via rail, water and motor. My assignment is somewhat different as indicated by my topic, "The Traffic Manager in an Industrial Minerals Operation."

Jan 1, 1969

By A. A. Odunaike, E. G. Okafor, M. H. Mokwe

Microscopic Studies were performed on ore samples from the Muro banded iron ore deposit in Nigeria and the Marampa iron ore deposit in Sierra Leone. Ore characteristics that affect processing of both ores were compared with a view toward assisting mineral processing engineers in choosing the most suitable methods for upgrading the ore. The Nigerian ore contains 30% to 37% (by weight) Fe and the Sierra Leonean ore contains 34% to 51% (by weight) Fe. Hematite is the main iron mineral in both ores. The Sierra Leonean ore is relatively coarse grained (typically around 250 µm) and can be upgraded by conventional gravitational methods. In contrast, the Nigerian iron ore is fine grained and must be ground to -74 µm to liberate the hematite for recovery by flotation. Both ores contain high percentages of phosphorus and sulfur, which are above the required specifications for direct reduction and blast-furnace practice. These deleterious elements can be rejected by grinding and flotation.

Jan 1, 1999

By C. D. Wittreich

The University of Idaho, Department of Metallurgical and Mining Engineering, through the Generic Mineral Technology Center, has been engaged in mine design research at the Lucky Friday Mine, Mullan, Idaho. The purpose of the research is to develop and implement the longwall underhand cut-and-fill mining method for conditions at the Mine. The longwall underhand cut-and-fill mining method involves backfilling mined stopes with a compacted tailings-cement mix. After the backfill has been allowed to cure, mining is resumed from underneath. Horizontal stresses in the Lucky Friday Mine are exceptionally high and rock bursts are a common problem. Beus and Chan (1980) have reported a 2:1 horizontal to vertical stress ratio at the mine with a 65-MPa (9,500-psi) maximum horizontal stress at the 1,295-m (4,250-ft) level. Using this mining method under these stress conditions, it is desirable to have a backfill material that has sufficient strength to safely carry the high horizontal wall loads while minimizing external steel supports.

Jan 1, 1987

By Raj K. Singhal

This paper is a report on a task force study dealing with many facets of computerization. The primary mandate of the task force was to examine the software and hardware currently available for application relating to reserve estimation, mine planning, economic evaluation, equipment selection, production scheduling and composite mine simulation and to evaluate how adequately the software fulfills the user needs in surface mining of oil sands and coal. To meet its objectives the task force consulted extensively with the users, developers and suppliers of hardware and software. The paper outlines the approach taken by the task force to fulfill its mandate, summarizes its findings and presents some pointers which might be useful to others considering this type of evaluation.

Jan 1, 1986

By Thomas P. Meloy

There is much interest in the automation of entire comminution circuits, At the present technological level it is possible to automate a circuit but to date it has not been done, To successfully automate a circuit, a number of problems must be solved. Not all of them are engineering problems. The purpose of this paper is to discuss some of these problems, as certain the implications of these problems and indicate solutions to them. In this paper the term "automation" is used loosely but in the popular sense. Namely, that a plant is automated if a computer is used to control the basic flow of the materials as well as setting the critical parameters in the process. Specifically, the discussion will concern itself with the control of comminution circuits from the dumping of the ore into the primary crusher until the final interface between the comminution circuit and say, the flotation mill in the case of a sulfide ore.

Jan 1, 1965

By H. Colijn

The problem of the freezing of moist raw materials, such as concentrates, in railroad cars during winter shipment has been a continuing source of both economic and operational trouble to the industry and to the railroad companies. The difficulties center around the discharging of frozen cargoes into the plant materials handling system. Because of cargo freezing, appreciable delays in car-dumping schedules occur each winter and cause additional expense for demurrage charges and for slowdown of plant operations. In one plant during one winter, a car dumper rated at 40 cars per day could dump only 3 cars per day in bad weather. Delays became so serious one winter, that 500 cars held in the yard became so badly frozen, that they were sent to the southern part of the United States to thaw after they accumulated an average of two months demurrage charges. These delays in car unloading become critical if unit or integral train concept is applied to the movement of raw materials. Anticipated savings in transportation costs through better equipment utilization are largely based on rapid loading and unloading cycles of whole trainloads. If freezing problems cannot be adequately solved, unit train operations cannot be operated to achieve the potentially large reductions in transportation costs. The freezing problem may tend to become even greater in the years ahead, because the unit train concept will allow the trains to run faster and consequently the heat loss will be accelerated due to the larger heat transfer coefficient. A compensating factor, however, will be the shorter travel time. Further, the sources of raw materials being mined are located farther north than before and the ambient temperatures during transit are going to be lower.

Jan 1, 1976

By R. A. Matuszak

In recent years, a new concept in the control of electrically powered excavators has come into existence. The new type of control system has come to be known as "static" control. The use of the name "static" to describe this system is somewhat misleading since this term refers only to one of the many advantages of this very important advance in excavator control systems. In 1959, the first truly "static" control for Ward-Leonard equipped electric excavators was designed, developed and placed in service. The control system, originally intended only as a more modern electronic type of alternate to the tried and proven rotating amplifier control system then in use, has since proven to be much more.

Jan 1, 1964

By F. G. Crack

This paper is based on the philosophy that the management structure and strategy required for mine construction and development projects are different from that required for routine production and maintenance operations in a mine. The purpose of this paper is to present an integrated approach to the management of mine development projects. This paper highlights the four major aspects of the integrated approach. First, a brief review of the various types of contract documents is provided. Second, the management organization of a project is discussed. Third, the project manager's role and the field supervisor's responsibility are briefly outlined. Finally, the use of scientific techniques for planning, scheduling, executing, and controlling projects is presented. Each of these aspects is important; however, each by itself cannot be expected to bring order or unifying impact to the complexities involved in overall project management. When all these aspects are coordinated, the result will be a sore successful project from conception to completion.

Jan 1, 1982