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By Nicholas T. Camicia

A career in the coal mining industry today offers students one of the most interesting and challenging opportunities available in the industrialized world. As reserves of other fossil fuels dwindle in face of the world's demand for energy, it has become apparent that coal, once the king of energy sources, must be relied upon again as the major fuel for powering industrial growth in developed and developing nations. Centuries of coal supplies lie beneath the earth's surface, assuring the world of a steady, plentiful supply of energy until science and technology can produce a way to harness and efficiently use renewable sources, such as solar. The need to increase our use of coal during the last two decades of the 20th century is reason enough to believe that the future growth of the coal industry is assured. A major impediment to that growth might be backward national public policies that could restrict the full utilization of our coal reserves. These policies could result from overregulation and a failure of the public to recognize that coal use, with proper techno- logical safeguards, is compatible with our society's environmental-quality objectives. Communication of this problem and its solution is a major undertaking of the coal industry in the 1980s. At the end of the 1970s, the American coal industry was producing approximately 635 Mt/a (700 million stpy) of coal. To meet the nation's projected energy needs by 1985, the annual tonnage must be doubled. A similar scenario is predicted for the rest of the world. Such growth in the modern international business world will require huge additional amounts of capital, equipment, and people who know how to wisely raise and apply the capital ; use the equipment productively; and deal with the many community, public, and governmental problems such expansion will create. Whether a student's interest is in actual mining operations, business administration, engineering, finance, law, industrial relations, marketing and sales, or public affairs, a career opportunity is available in the industry.

Jan 1, 1981

By Harold E. Goetzman, Blair R. Benner

The U.S. iron ore industry is located primarily in Northern Minnesota and Michigan's Upper Peninsula with one additional small plant in Missouri. There are currently some 10 plants operating that produce about 48 million tons per year of pellets. The major reagent use occurs in the three general areas of: flocculation, flotation and pellet additives. Minor areas of usage are for corrosion inhibition and dust suppression. Current practice as to types of reagents, consumption, and method of application are reviewed. The interaction of reagents with other parts of the process are discussed. Also included is a discussion of future reagent needs.

Jan 1, 1994

The primary goal of a maintenance information system should be to aid the maintenance department in providing the required equipment or plant availability at the lowest possible cost. To achieve this goal, the system must provide information in support of the following objectives: (1) establishing the best fleet, equipment, and component configuration; (2) establishing the best maintenance program; (3) executing the defined maintenance program efficiently; and (4) monitoring equipment availability. These objectives can be satisfied with five groups of reports. Each of these groups should provide regular, periodic reports to aid in planning and monitoring trends, exception reports to identify problems, and on-request reports to provide analytical capabilities.

Jan 1, 1979

By Frank S. Hicks, Y. Charles Guan, Glenn A. Gruber

This paper describes a two-part program funded by the Florida Institute of Phosphate Research and performed by Jacobs. The first part of the program was to examine the application of ultrasonic treatment to clean phosphate particle surfaces. Florida phosphate pebble and rougher flotation feeds were treated in an ultrasonic trough to remove clays. Also, the de-oiling of rougher concentrates by ultrasonic treatment was tested. In order to improve the clay removal efficiency, viscosities of primary cyclone overflow from six beneficiation plants were studied in the second part of the program. Viscosities for different samples at the same clay % solids vary significantly, and increase exponentially with clay % solids content for the same sample. A method of controlling cyclone operation using on-line viscosity measurements and pump box level sensors is proposed to logically improve primary cyclone performance.

Jan 1, 2002

By Edmond O’Donovan

Mooranbah North is a new greenfield project in Australia's Bowen Basin that is projected to produce 4 mtpa of hard coking coal from a single longwall. Located in Central Queensland in Australia's northeast, this is one of Australia's main coal producing regions. From the outset, Mooranbah North's approach to equipment selection has differed markedly from that usually taken in the mining industry, and the conveyor industry in particular. Until recently, no performance requirements have been placed on conveyor equipment suppliers. This arose from a practice of purchasing components in an ad-hoc manner from a variety of sources, and the mine then configuring the system. More recently, single source supply has been adopted as a means of obtaining some performance guarantee, usually expressed in terms of system availability. Unfortunately, the term "availability" has a multitude of definitions, particularly in the underground coal sector. A conveyor availability of 98% is a common goal but this rarely means the conveyor must operate 165 hours/week, 52 weeks/year. There are mines that have one maintenance shift for each production shift and claim availability of 100%. What is meant is that no down time is logged to the conveyor during the hours that it is wanted. This "generous" definition of availability would not be tolerated in many industries and nor should it. Unfortunately, a true definition of availability, such as is applied to steam turbines in the power generation industry, is not particularly helpful. Five day/ week operations would immediately face a 28% penalty against 7 day rosters, and there would be no sensible manner in which weekend maintenance could be incorporated into the availability formula. The approach adopted by Mooranbah North was to specify a period of "Failure Free Operation," which would be followed by a maintenance period. This

Jan 1, 1998

By R. A. Jankowski

Although the number of operating longwall mining systems has remained relatively constant, longwall production levels during the last five years have increased significantly. In the United States, longwall mining now accounts for approximately 50% of all underground coal production. While longwalls are highly productive and offer other advantages, operations employing this method of mining continue to experience dust-compliance problems. This increased longwall productivity has meant that far more dust is being produced. An improved understanding of the longwall face-ventilation system and the advancement of face-ventilation technologies are necessary to ensure all face personnel are allowed to work in an environment that is free of excessive levels of airborne respirable coal mine dust. The Dust and Toxic Substances Control Branch, National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, examined several basic principles of the long wall face-ventilation system and has evaluated the effectiveness of numerous improved face-ventilation techniques for longwall mining systems. These include identifying improved techniques for measuring face-ventilation parameters on longwall mining sections and investigating the fundamental relationship between face airflow and the entrainment and dilution of respirable coal mine dust. Studies have been completed to determine the impact on face dust levels of using belt entry air to ventilate the longwall. Novel methods have been identified to increase the face air¬flow and to manage face airflow to effectively minimize dust exposure to face workers. Unique systems of auxiliary face ventilation have been developed and evaluated at full-scale, simulated longwall test facilities. The theoretical and applied aspects of each of these principles and technologies are discussed. Application of these results throughout the longwall mining industry, as documented from surveys conducted in the early 1980s and 1990s, have reduced the health hazard associated with excessive exposure to respirable coal mine dust.

Jan 1, 2000

By Pierre M. Matheron

TRANSMANCHE-LINK is responsible for designing, developing and implementing the project for a fixed link under the English Channel, comprising two running tunnels of diameter 7.6 metres and a service tunnel of diameter 4.8 metres. The three tunnels will all be 50 km long, with 37 km bored through chalk marl at a depth of 40 metres under the sea bed. The tunnels will be driven from both sides of the channel from intermediate addits above the coastline on either side with a 55 m access shaft at Sangatte in France and two "descenderies" or inclined tunnels addits and a shaft at Shakespeare Cliff on the English side. A total of eleven tunnel boring machines will drive the 150 km of tunnels. The major part of the tunnel linings will be built of precast reinforced concrete segments, and two plants have been specially built to produce the necessary 725,000 segments. Seven million cubic metres will be evacuated on wagons along the tunnels and then lifted by belt conveyor on the English side, and by hydraulic mucking from the bottom on the French side. Preliminary work started early in 1987 with manufacture of the first boring machines, construction of five precasting plants, boring of the Sangatte shaft in preparation of the Shakespeare Cliff entrances. The principal project dates are :

Jan 1, 1987

By E. Jannoulakis

This paper introduces a practical methodology for analyzing vi¬bration records in view of improv¬ing blast designs and preempting anomalous vibrations. This technique, which is based on empirical data, uses a blasting-efficiency determinator (BED) as an indicator of vibration-energy transmission. The method was tested using data from a blasting event at an open-cast coal mine in the province of New Brunswick, Canada. The results derived from the BED values showed that geology and delay timing were probably the principal factors that induced high-intensity vibration propagation.

Jan 1, 2000

By Jean-Michel Rendu

Accurate modeling of the semivariogram is an extremely important step in the geostatistical analysis of mineral deposits. Automatic fitting of a mathematical model is often possible but not necessarily desirable. Significant geologic and statistical information must be taken into account in the fitting process, which is not always available to the computer. Manual fitting of the model is, on the other hand, extremely time consuming. Interactive graphics are best suited to optimize the process. A number of interactive methods are described, which are adapted to the modeling of semivariograms in one-, two-, or three-dimensional environments.

Jan 1, 1982

By Herschel H. Potter

While preparing this paper, I soon realized I had a problem in defining what injuries should be classified as "personal." Admittedly, in some cases, falls of persons, sprains and strains, pulling and pushing injuries, and back injuries may have been caused by the individual. But, I believe the number of injuries directly attributed to an individual's carelessness is relatively small in comparison to the total number of injuries in those categories. For discussion purposes, the injuries most often considered to be personal, that is, caused by individuals are those classified as back injuries. My paper will be devoted to back injuries because this category represents the greatest number of injuries occurring in coal mining. A man's best friends are his wife, his back, and his dog. The back, however, has a reputation of not being as faithful as his other two friends.1 "Industrial back injury is one of the major occupational health problems plaguing industry to- day. According to national surveys, back injury accounts for more lost time than any other occupational injury and costs companies thousands of dollars in compensation, medical fees and over- time pay."2 A study conducted by USA Today found that back ailments afflict an estimated 75 million Americans, have totally disabled about 2.5 million adults, lead to as many as 200,000 required surgeries each year, are a leading cause of absenteeism and disability, are the second leading cause of hospitalization, are responsible for 18 million doctor visits a year and cost about 93 million work-days annually. The cost to industry is estimated at $14 billion a year.3 During the past 30 years, a great deal of accident prevention education has been directed toward the reduction of back injuries. However, this effort has not produced any great change in the incidence of the injury. Back injuries should be of the utmost concern to everyone here today. I don't need to tell you what the incidence rate is for back injuries, nor will I use any statistics to inform you of the incidence rate for the coal mine industry or any specific mine. It is only important to know that the number of back injuries is excessive. Back in- juries resulting from lifting have been and continue to be one of the most constant and undiminishing problems in the occupational environment. The fact is, we use our backs to per- form work that the back was not designed to do. Historically, manual materials handling related accidents have consistently accounted for the largest percentage of all industrial accidents. In fact, over 25 percent of all industrial accidents are related to handling of materials.4 In underground coal mining operations, material handling accidents account for even larger percentage of lost time injuries. In 1983, for example, they accounted for 34 percent of all lost time injuries and 32.6 percent of all non-lost time injuries. 5 I want to use one example of a task that will illustrate what I have just said: the building of a concrete block stopping. Each solid concrete block will weigh from 60 to 70 pounds. To build a stop- ping 6 feet high and 20 feet wide will take approximately 80 blocks. On the average, these 80 blocks will be handled at least four times from loading into the conveyance for transportation to being placed while constructing the stopping. This generally requires repetitive lifting from ground level. The next three slides demonstrate the lifts

Jan 1, 1986

By Harry M. Conger

Good afternoon, fellow members of the international mining community. I appreciate the opportunity to participate in this special three-day, international gathering, and to join with you in honoring one of my very good friends, Doug Fuerstenau. It couldn't be more fitting to have this kind of event to mark Doug's 60th birthday. You know, in addition to his faculty position at the University of California in Berkeley, Doug is a member of the Board of Directors of our Homestake Mining Company. So it is a double pleasure for me to help pay tribute to one of the outstanding academicians of the mining industry as well as a man with whom I work closely in running Homestake. I have been asked to talk about "The Future of Precious Metals," but I will concentrate my remarks on gold. Since the theme of this Symposium is "Challenges in Mineral Processing," what I'm going to talk about is a challenge that relates especially to a major problem faced by those of us who process ores to recover gold. I noted that in the Scope of this Symposium, it stated: "the mineral industry is currently facing many challenges to improve the economics, operating efficiencies and environmental concerns of the mineral processing system." I couldn't agree more with that statement. I think that a need exists for us to address this situation as it involves gold. And who better to consider this than the worldwide leaders of mineral processing research here assembled. I start with the premise that we need a new method for cyanide use or a chemical to replace sodium cyanide entirely. In the case of using cyanide differently, I see a continuing difficulty in getting general public acceptance regardless of how

Jan 1, 1989

By John F. Martonik

When OSHA came into existence in 1970, it adopted national consensus standards to improve safety and health conditions in work places. Coke oven emissions, which are proven to cause cancer and respiratory diseases, were regulated by the coal tar pitch volatile standard, adopted from the 1969 edition of the Threshold Limit Values for Airborne Contaminants by the American Conference of Governmental Industrial Hygienists. The coal tar pitch standard, based upon the benzene soluble fraction of total particulates, limits the personal exposure to 200 micrograms of the benzene soluble fractions of total particulate per cubic meter of air. This standard can be classified as a performance standard because only general limits are set which allows the employer to choose for themselves the means to comply. Both the United Steelworkers of America and the American Iron and Steel Institute petitioned the Secretary of Labor to write a new standard for coke oven missions, each thinking the coal tar pitch standard unsatisfactory.

Jan 1, 1980

By Kenneth N. Han, Jianshe Liu

Various techniques used in the removal of metal ions from effluent streams have been reviewed. These techniques include recovery of metals by biological treatment, chelating agents, adsorption, ion- exchange and chemical precipitation. The main thrust of this paper however, is concerned with the removal of cadmium and zinc ions from the solution by adsorption utilizing liquid fluidized beds. The bed particles used were silica of 150x200 mesh. The range of the concentration of these ions studied was 10-3 to 10-5 M. Important variables examined included flow rate, concentration of metal ions and amount of bed particles. A mathematical model describing the concentration profile of metal ions in the axial direction in liquid fluidized beds has been developed. The equation of continuity was solved numerically and the results were used to predict the recovery of metal ions in fluidized beds.

Jan 1, 1992

By Alfred Jr. Petrick

Modelling of cash flows and calculation of net present value of rate of return over the expected life of a mine/processing unit continues to be the accepted basis for mineral investment decision-making. The computer and spreadsheet programs have greatly improved ability to perform sensitivity and risk analysis, hence our ability to deal with key analytical problems. These problems of cash flow analysis result from the necessity of forecasting an uncertain and risky future. Cash flow models begin with the critical assumption of a "design basis", then integrate all of the variables relevant to the investment decision including forecasts of price, cost, taxation, financial conditions, and company strategy. Alternate "scenarios" portray possible future outcome of the investment decision. The potential for straying from reality is enormous. The computer has eliminated the time consuming hand calculations from the cash flow analysis, but the analyst still struggles with the risk of trying to predict "how the project will really turn out".

Jan 1, 1991

By R. L. Grayson, T. L. Dickinson, C. G. Anderson

Sponsored by the EPA, USGS, DOE, and NSF through the Committee on Earth Resources, the National Research Council’s Committee on Material Flows Accounting of Natural Resources, Products, and Residuals, created in August 2002, studied the value that material flows accounting, which can track the flow of a material from the time it is extracted to its ultimate disposal, may provide for making better integrated economic, social, and environmental policy decisions. This could be a crucial technology for the mining industry to incorporate. This paper will recount the statement of tasks, the study process, and the science-based conclusions and recommendations reached.

Jan 1, 2004

By Alexander Filimonov, Yury Bloshteyn

Ventilation of gas mines keeps necessary sanitation and hygienic conditions for labor in mines and increases the safety by dilution and removal of hazardous and dangerous gases in accordance with the safety rules. Several different concepts exist at the present time to design mine ventilation control systems. But technical ideas have been developed inadequately and technological solutions have not been investigated experimentally enough to build a serviceable system. This paper presents a new concept of high- efficiency mine ventilation process control system (MVPCS). The methods of modern system engineering (Kalman, 1969) are used to establish its functional and algorithmic structure. A three level hierarchical principle of system building is considered.

Jan 1, 1991

By H. H. Murray

New and improved beneficiation techniques are available to allow the production of clay minerals of exceptionally high purity. This is particularly true for kaolins and smectites. Wet processing techniques include particle size separation, high intensity magnetic separation, chemical leaching ,flotation, and selective flocculation. The blending of clay minerals with other minerals provides opportunities to make special ceramic materials such as cordierite and other minerals that have very special ceramic properties including low heat expansion, high fired strength, low absorption, and other desired qualities.

Jan 1, 1990

By R M. Whyte, D McArthur, A Macintosh

In designing a gold extraction circuit utilising carbon­in-pulp (CIP) technology a number of process options can be considered. These include various combinations of leach or pre-leach, CIP or carbon-in-leach (CIL) and conventional counter-current or carousel CIP (or CIL) circuits. Factors affecting the process selection include the project's sensitivity to capital and working costs, the project life, and the mineralogy and head grade. Each process option has it's own advantages and disadvantages. This paper compares both the financial and technical aspects of the flow sheet options. The flow sheet, design aspects and operating performance of Anglogold's West Wits No. 2 and 3 Plants which are leach, pump-cell circuits are described.

Jan 1, 2000

By Mark E. White, John H. McCowan, Michael C. Costello

Minproc Engineers has carried out the design construction and commissioning of thirty two process plants in the period 1978-87. Twenty eight are gold silver recovery plants, and of these twenty two were gold alone and six were gold and silver. In most plants carbon was used for gold adsorption. Desorption has been carried out using the USBM Homestake method, the Anglo American Research Laboratories method, and the Micron Methanol method. Electrowinning has utilised steel wool, stainless steel wool, and aluminium cathodes. Electrorefining using polished stainless steel cathodes is practised. This paper summarises the experience gained in these operations

Jan 1, 1987

By William Ives

My presentation is from the viewpoint of the industrial mineral geologist, which is a relatively rare breed. Very few geologists become involved with industrial minerals for two reasons, I think: (1) Much of the industry utilizing non-metallic minerals has developed without the use of geologists in the begin¬ning and many of the management people, who generally derive from the processing plant supervision, tend to take raw materials for granted; and (2) non-metallic minerals are a very insignificant part of the curriculum of virtually all colleges granting a geology degree. One learns about the geology of industrial minerals by working with it. This "on-the-job-training" is probably best because it brings the geologist into close quarters with the production people and the production process. And the industrial minerals field has a distinctiveness when compared with the petroleum or metal mining field in that each deposit can yield a material differing in some aspect from that in any other or within the same deposit. The petroleum from a well in a given field will be similar to that from any other well, but a limestone on one side of a hill can differ signifi¬cantly in elemental composition, calcinability, soundness, specific gravity, or some other factor from the same ledge on the other side of the hill. This characteristic of almost certain variability creates problems sooner or later and provides for much of the employment of industrial mineral geologists. My job seen from the viewpoint of management is "Find us some rock we can extract and process at a profit." The industrial non-metallic geologist has much the same problems and approach as a detective. I do not mean the TV variety with the big mouths and the unfailing knack of spotting the wanted criminal immediately in a city of ten million people. Any real detective will tell you it takes leg-work, knowhow, and persistence to make a case. The same is true for the geologist who finds rock which can be quarried at a profit. I am responsible for finding raw materials for a company which manufactures portland cement and

Jan 1, 1977