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By J. B. Mitchell

Comminution methods for base metal and precious metal ores have had considerable attention from mine operators, equipment suppliers and design engineers for many years and much of their work has been well reported. This interest derives from a healthy concern with the costs of comminution, often the largest single cost factor in ore dressing of hard ores. Many imaginative innovations have resulted. One notices a trend toward autogenous and semi-autogenous methods, combined with a trend toward very large equipment. Unfortunately, there has been less obvious cost incentive to experiment with softer ores. This is unfortunate because the consequences of inappropriate comminution methods can have an important effect on overall economics by influencing down stream processing and salability of final products. This paper concerns some of the factors to be considered in the selection of comminution methods for potash ores, and gives some specific examples to illustrate some of the principles involved.

Jan 1, 1969

By Russell L. Dahl

In a continuing effort to improve plant efficiency, United States Steel's Atlantic City Ore Operations completed the rubber lining of its balling drums in late 1982. This resulted in benefits of reduced bentonite consumption, reduced maintenance costs, improved production rates, and lower power consumption. These advantages far outweigh the disadvantages of increased oversize production and increased surging on the roll screen sizing devices. Certain operating characteristics and variables are discussed herein.

Jan 1, 1983

By J. M. Keane

SMEThis loaner is concerned with important criteria relative to the design of small flota¬tion concentrators. For the purpose of this discussion a small flotation concentrator is defined as a facility having a designed ore feed rate of 1,000 metric tons per day (MTPD), or less. The decision to design and construct a small flotation concentrator is the culmination of a series of logical steps relative to the ex¬ploitation of a potential ore body. The information required for a rational and timely decision regarding plant design and construction is usually contained in a feasibility report. The information required in a thorough feasibility report has been summarized (1) (2) as follows: Type of mine or plant and proposed daily, monthly, and yearly production of all intermediate and final products. Quantity of indicated ore reserves. Location of project illustrated by a map showing surroundings, trans-portation facilities, and existing utilities.

Jan 1, 1980

By B. Grosso

The National Italian Regulation concerning environment protection imposes that industrial areas are provided with systems aimed at preventing the circulation of contaminated groundwater. These systems can be static or dynamic and operate basically by intercepting the contaminated flow. Their effectiveness, realization time and costs depend on the intervention type and on the features of the specific site. The selection of the best solution is complex and the results obtained by this selection may be affected by residual risks related to the uncertainty of the hydrogeological and geotechnical characterization of the site. With regard to the industrial area of Portovesme, located in the south of Sardinia, the paper presents the analysis of alternative interventions aimed at the protection of the groundwater. The attention is focused on the evaluation of their effectiveness, impact on environment and, finally, time and costs of construction.

Jan 1, 2008

By J. T. Crawford

The purpose of this paper is two fold. It will: (1) examine leasing analysis as a project evaluation criterion, and (2) compare the cost of leasing with other methods of financing. The use of leasing has grown extensively in recent years as a method of obtaining equipment. The computer industry has been highly dependent upon leasing from its earliest days to dispurse its equipment to the customer, while airlines and railroads acquire large segments of their aircraft and rolling stock by leasing. Over the last few years the mining industry has leased haulage trucks, bulldozers and other equipment of similar nature.

Jan 1, 1974

By Lawrence R. Molsather

Certain hydrologic parameters are affected by development of a mine. These include the area, yield, and storage in a watershed. Alteration of these parameters results in variations in lake levels and stream flow rates and in changes in ground water elevations and gradients. These factors have become increasingly important in light of present environmental design standards and government regulations. Mitigation of adverse hydrologic impacts can be costly and can create operating constraints which complicate the mining process.

Jan 1, 1980

By Erich Sarapuu

Today's increasing needs for rapid excavation have stimulated efforts to break rocks without explosives. The application of electric energy for this purpose has been studied by a number of investigators. Following principles have been used in electrical rock breaking: 1. induction heating5 2. high frequency heating4, 14 3. microwave heating6 4. contact resistance heating9,12 5. resistance heating11,13 6. electron beam heating1, 3 7. plasma jet heating2, 8 8. arc heating7 9. condensor discharge energy14 In this paper the presentation of the principles of electrical fragmentation is limited to a process called "electrofracing". This technique uses electrical heating of rock by electrode contact resistance9 and resistance heating" phenomena. The electrically induced stresses inside of rock generate forces which break up the material. The fracturing of ore takes place by tensile stresses instead of compressive forces. The electric energy merely creates fractures in the rock and the separation of fractured material takes place by subsequent mechanical handling. Energy requirements in secondary breaking of iron ores have been about one to two kilowatt-hours per ton of ore. Power requirement is a function of the degree of fragmentation.

Jan 1, 1969

By Frederick B. Henderson

The US Environmental Protection Agency (EPA) has tried many regional and laboratory efforts to develop measurement and monitoring techniques using environmental remote sensing technologies. In 1997, the agency established the Advanced Measurement Initiative (AMI): This is a eadquarters-level program, operating under the auspices of the EPA Office of Research and Development. The program is one result of the April 30,1996 White House Conference on Advanced Monitoring of the Environment. The EPA was encouraged to work with other federal agencies to leverage its remote sensing capabilities and use them to improve the efficiency, cost-effectiveness and flexibility of environmental measurement and monitoring for regulatory compliance and reinvention. During the fall of 1996, the EPA and the Department of Energy developed an interagency effort to broaden the use of governmental technologies for environmental measurement and monitoring. In addition, the EPA and the National Aeronautics and Space Administration (NASA) conducted joint workshops on the use of NASA remote sensing and other technologies for water quality and pollution applications. In the meantime, the EPA proceeded with an industry-proposed workshop to explore ways to cooperatively examine new research and to develop commercial remote sensing systems. It also examined how these systems might become accepted by the EPA in the regulatory and compliance processes. In particular, industry was interested in where new remote sensing capabilities might fit in with EPA's efforts at regulatory reinvention. Historically, the mining and petroleum industries have been reluctant to experiment with or use environmental remote sensing. They were concerned with the unknown liability from potential discovery of previously unknown environmental problems. Moreover, resource industries have been reluctant to use remote sensing for environmental applications where the EPA did not accept such data or information as part of the compliance process. Acceptance by the EPA of these advanced measurement and monitoring technologies (AMMT) will be a major reason for industry's increasedd use of remote sensing in environmental "applications for regulatory compliance. In July 1997, the EPA Office of Research and Development hosted at the Colorado School of Mines a stakeholders workshop on the AMI program and industry-government collaboration. The workshop's aim was to demonstrate the usefulness of AMMT technologies for environmental applications. Stakeholders included the mining and petroleum industries; environmental services companies; state environmental agencies and local governments; remote-sensing, value-added companies and data suppliers. The workshop used specific technologies and applications as a way to develop collaborative demonstration projects for several AMMT technologies covering different environmental problems. The workshop focused on the use of highly sensitive hyperspectral (very narrow spectral bands), geographic information systems and surface mapping to identify active acid-producing mine dumps and wastes from benign wastes at Leadville, CO. NASA's advance infrared imaging spectrometer (AVIRIS) was the instrument used. It was developed at California Technology's Jet Propulsion Laboratory. The EPA, the US Bureau of Land Managment (BLM), the US Geological Survey and several environmental service contractors sponsored the overflight and data evaluation. The AVIRIS study demonstrated reliability (95% correct surface mineral identification) and cost-effectiveness of this technology to accurately map and discriminate active acid-producing mine wastes from benign wastes. It could also predict which streams would be effected by acid and toxic mineral drainage. The BLM'said that the AVIRIS overflight could save it $500,000 a year in surface sampling costs at Leadville. The AMI workshop further outlined five 1997 funded AMI projects of potential interest to the mining industry. They were: ? Mine waste characterization using remote sensing methodologies at Asarco's Ray Mine in Arizona. ? Predictive emissions development and testing in

Jan 1, 1997

By A. Frank Alsobrook

DOUG HALBE: Thanks, Terry. And in spite of your introductory comments, I'm going to attempt to continue our hallowed tradition of saying nice things about the speakers. This is really a serious comment now. We, as mineral processing and mill people, don't often talk to people outside our general operating area. One thing that we've tried to do in this operators' symposium is get speakers from various types of plant operations to help illustrate all the things we have in common. Our next speaker is from the industrial minerals area. I think there's a lot to be learned from industrial minerals operations. Some of the people in the last session learned some things about fine grinding in industrial mineral operations. I was a little surprised to see people there grind to 2 microns. Our next speaker is Frank Alsobrook. Frank is another nonmetallurgical engineer. He has a degree in geology, a master's of science from the University of Wisconsin. He's had his own very successful consulting company for a number of years. This is your 11th anniversary, Frank? Very good. He's also the immediate past chair of the industrial minerals division. I think the folks at the speakers' table should be ashamed. You have been so rowdy that Frank chose to sit in the audience. [laughter] We'd like you to come up now, Frank, and tell us some things that you've seen that might be useful to us. INTRODUCTION FRANK ALSOBROOK: The three topics addressed briefly are (1) teamwork and operations modeling, (2) the pitfalls of capital conservatism, and (3) the potential for by-product recovery. Ideas for improvements in these areas are not unique to industrial minerals but apply to metal mining and processing operations, as well. Several additional topics are suggested at the end of the paper.

Jan 1, 1998

By Charles H. Grant

Blast design methods generally deal with end points or limits of design such as spacing, burden, stemming depth, etc. Even cratering design deals with limits defined as a function of energy decay to a limit. Although this crater method provides a better method than trial and error judgment it does not take into consideration the distribution of energy throughout the material to be blasted. This paper deals with a method of examining this distribution with the aid of a computer and how changes in blast design affect this distribution. First I would like to explain the equation used to develop the energy summations throughout the blast. As shown in Figure I a series of drill holes are drilled to various depths starting by placing the explosive charge on the surface and then at various depths until a sufficient depth of hole is reached to exceed the ability of the explosive energy effect to reach the surface of the ground. All volumes of explosive are the same, all holes contain the same explosive and the drill hole diameter is the same.

Jan 1, 1980

By John S. Owens

The National Steel Pellet Project and the Butler Taconite Project are operated by The Hanna Mining Company in the vicinity of the towns of Keewatin and Nashwauk, on the western Mesabi Range. Production began in 1967, after seven years of exploratory and development diamond drilling and reconnaissance magnetic surveys, Previously, direct shipping hematitegoethite ores and gravity concentrates had been produced in the area from numerous open pits and several underground mines since the start of the century. Total shipments of these oxidized ores amounted to more than 200 million tons, but at the present time such reserves are nearly exhausted, and there are no mining operations in the Keewatin-Nashwauk area except at the two taconite projects. The locations of all of the present taconite operations on the Mesabi Range are shown in Figure 1, extending for a distance of about seventy miles from the Butler plant to the Dunka River area. The Butler and National plants have a combined rated capacity of 4.4 million tons of pellets. Their reserves cover a combined strike length of about eight miles on the Biwabik iron formation. All of the intervals between present taconite operations on the Mesabi are potential sources of additional magnetic taconite; in particular, exploration and economic studies have been carried out by Jones and Laughlin Steel Corporation in the Biwabik area between Aurora and Virginia, and by Pickands Mather and Company in the Hibbing area. However, west of the Henna and Butler holdings, it appears unlikely that magnetic taconite exists in commerical quantities at economic depths due to extensive oxidation of magnetite to hematite.

Jan 1, 1968

By S. W. Thomas

One of the most difficult tasks associated with placer mining is the sampling of the deposit. More placer projects have failed due to inaccurate assessment of the reserves than to any other reason. Within the realm of placers, those containing valuable minerals with a high unit value .are more difficult to sample than those with larger bulk, lower unit value minerals. Some items to consider when sampling a placer deposit are as follows: A) A relatively large size sample is needed for accurate valuation of the ground being tested. Placers are composed of many sizes of gravel which makes a representative sample difficult to obtain. B) When sampling placers for high unit value minerals such as gold, any error in mineral content of the sample will be magnified in the calculation of reserves.

Jan 1, 1985

By L. E. Allen, J. F. Abel, D. R. Morgan

The Waste Isolation Pilot Plant (WIPP) is a geologic repository for disposal of transuranic waste and is operated by the U.S. Department of Energy (DOE). The repository is located at a depth of 655 m in the Permian age salt beds of the Salado Formation, 40 km east of Carlsbad, NM. A key component in the design of the WIPP repository is the installation of concrete structures as panel seals in the intake and exhaust drifts after a panel has been filled with waste containers. The DOE has proposed several panel closure design modifications to the EPA. EPA approval of the changes is required since the details of the designs are specified in EPA’s final rule as a condition for WIPP certification. The Environmental Evaluation Group, in its role of providing technical oversight on the WIPP project, has evaluated the proposed modifications. An analysis of this evaluation is discussed.

Jan 1, 2003

By W. C. Streib

A wide variety of materials have satisfactory to superior insulating properties and can be used to control the flow of heat, provide energy savings, improve personal comfort and contribute to personal safety. Such materials range from completely organic products--both of natural origin and synthetics--to completely inorganic. In many cases, thermal protective systems are actually combinations of both. Obviously, those insulating materials which are principally inorganic have the inherent advantages of low to minimal combustibility as well as utility at vastly elevated temperatures. Both of these properties are highly desirable in providing not only thermal energy conservation, but also personal safety in residential and commercial applications. As the thermal insulation needs of man and industry have developed, there has been an ever-increasing demand on the minerals industry to provide the resources required to fill these needs. On a global scale, industrial minerals have become the fundamental base upon which today's thermal insulation industry has been built. The use of minerals to control heat flow range from the most unsophisticated applications to those requiring the ultimate in scientific technology. In many cases the minerals are themselves converted in- to the major insulating media; for example, fiber glass, rock wool or refractory fiber. In other cases, minerals are used as the chemical reactants to form the binder matrix which in turn provides the product strength required for adequate handling and installation; for example, calcium silicate bonded products wherein the binder is the reaction product of lime and silica. In still other cases, low density mineral products are added to a high density binder System to provide lower weight and better insulating properties; for example, the use of expanded perlite in concrete.

Jan 1, 1976

By G. M. L. Robinson

Mineral Processing Wastes, as defined by the Environmental Protection Agency (EPA), has determined that most of the mine wastes will be regulated pursuant to subtitle D (Solid Waste Regulations) of the Solid Waste Disposal Act while specific mine waste categories will be regulated within the framework of the Toxic Substance Control Act. Though EPA's determination currently relieves the industry of the regulatory constraints mandated by the Resource Conservation and Recovery Act (Hazardous Waste Regulations) Subtitle C regulatory framework; the industry is not granted immunity from historical or current environmental regulations related to listed or characteristically hazardous or solid wastes. Because of the current regulatory trends and the need to implement cost effective remediation alternatives; advanced currently available on-site remediation technologies are available to minimize, reduce, contain or prevent environmental impacts related to mining and processing activities. In light of industry technical needs, an overview of the research and commercially available remediation technologies will be discussed and a brief discussion of the strengths and weakness of each technology will be presented. Technologies to be discussed includes stabilization, solidification, soil wash, soil flush, thermal distillation, pump and treat, metal extraction, centrifuges, filter presses, bioremediation, and incineration.

Jan 1, 1992

By Dave G. Osborne

With the growing exportation of coal from North America to the Pacific Rim countries and Europe, has come an increasing awareness of the need to determine economically optimized amounts of incombustibles (ash and moisture contents) for the shipped product. Despite the fact that demand bas caused a steady improvement in selling price, particularly for thermal coals, growing production and transportation costs have compelled producers to keep a sharp eye open for ways and means of minimizing the latter since this probably represents the greatest single potential for making savings. Consequently the Coal Industry has become acutely aware of the economic ramifications of eliminating moisture in particular, thereby producing further saving in the cost of transportation of product from the mine to the consumer. There is, however, a lower limit to which dewatering or drying can be taken and this relates to dustiness which is a function of the characteristics of the coal and the methods used for handling and storage during trans-shipment. Overdrying can lead to serious dust losses and difficulties in handling particularly if the coal contains a large proportion of fines. The ways and means for achieving this "happy medium" of optimization in moisture removal are seemingly undergoing gradual modification largely assisted by the following factors. a) Improvement in effectiveness of coal dewatering and drying equipment. b) Improvement in operational availability and utilization of the equipment. c) The development of surfactants, polymer flocculants and other agents which in many cases can be almost tailor made to suit specific applications.

Jan 1, 1982

By Robert W. Curtis

Kaiser Aluminum & Chemical Corporation's (KACC) entrance into the alumina market began in 1946 with the purchase of a small plant in Baton Rouge. Louisiana. Since that time KACC has been involved with the design, construct; on, and operation of many alumina plants around the world. One of these plants is located in Gramercy, Louisiana. The Gramercy Works is a multiplant installation consisting of an alumina plant, a caustic-chlorine plant, a petroleum coke calciner and a fluorochemicals plant. Each of these plants require their own specific environmental control programs to abate pollution. Kaiser has made significant progress through the years on their own initiative in pollution control. But many new challenges have been and continue to be created with the enactment of environmental laws. The 1970 Clean Air Act Amendments, the resurrection of the old "Refuse Act" in 1970 and finally the 1972 Federal Water Pollution Control Act Amendments prompted the formulation of our current philosophy towards the abatement of pollution. Since the formulation of these complicated pieces of legislation, others equally complicated, have come to being. The Federal Insecticide, Fungicide and Rodenticide Act as amended by the Federal Environmental Pesticide Control Act of October, 1972, the Toxic Substances Control Act of 1976, the Solid Waste Disposal and Resource Recovery Act of 1976 and the Safe Drinking Water Act sighed in December of 1974 have all contributed to the challenge for an alumina plant to meet regulatory constraints. However, this paper will only discuss the alumina plant?s environmental programs designed to meet compliance with air and water pollution legislation. At the Gramercy Alumina Plant, over $25 million has been spent for pollution control since 1969. The Gramercy Plant is a prime example of KACC's commitment to meeting the environmental challenge.

Jan 1, 1978

By Alan C. Richter

Introduction The East-West Gateway Coordinating Council is an organization of local governments formed in 1965 to identify regional problems and to formulate policies, plans and programs to resolve them. The major goal of the Gateway Council is to improve the quality of life for the citizens of the St. Louis Region. While East-West Gateway Coordinating Council is the organization I represent and it only deals with the St. Louis Metropolitan Area, you will find one or more similar organizations in each of our nation's urbanized areas. As a result, for illustrative purposes, I will use my organization to portray what is happening nationwide. For example, in order to eliminate duplication, the Council reviews local applications for approximately 100 federally funded programs in such areas as highways, mass transit, parks, water treatment, and sewers before they can be sent to the appropriate funding agency. The Council's varied functions place it in a unique position of receiving more and more responsibility for developing strategies of implementation of various environmental regulations. This is due to the fact that environmental control is a relatively new field and we, as a country, are relatively inexperienced. The resulting regulations and guidelines will depend, to a great extent, on what the general public is willing to accept in terms of controls and what price they are willing to pay in terms of taxes and increased costs. Land Use: Growth vs No Growth This is perhaps the most encompassing environmental issue. We, as a nation, are beginning to realize that land is a limited natural resource and that the way we choose to use 'this resource affects many other aspects of our lives--whether we can catch edible fish in the Mississippi, how much we pay for sewer services, if we can swim in a

Jan 1, 1977

By W. G. Willson

Low-rank coal (LRC) drying processes are generally categorized by operating temperature, drying environment and type of feed (either sized or ground coal). Within these broad categories, drying processes differ according to the type of drying equipment and methods of quenching and stabilizing the dried products. This paper focuses on the produce quality of various LRC drying processes including conventional low and high temperature evaporative drying and non-evaporative, hydrothermal drying. The former may be preferred if the dried product can be utilized immediately, but moisture re-absorption, spontaneous heating and fines production during handling are problems associated with longer term storage, transportation and utilization. Methods for reducing these problems are discussed. Hydrothermal processing is an advanced technology featuring high pressure, non-evaporative drying, which solves stability problems by producing a liquid fuel.

Jan 1, 1997

By Richard Kojo Gabah

Western mining companies are entering an African critical minerals market where access is harder to secure, risk is being priced more sharply, and execution advantages are increasingly decisive. The continent holds significant reserves and production potential of cobalt, lithium, copper, graphite, manganese and rare earths critical to the energy transition, yet Chinese-aligned capital has built a structural edge in access and execution speed. Simply signing narrow offtake agreements to buy output is no longer sufficient. Western firms win when they convert quality orebodies into bankable projects by reducing aboveground risk faster than competitors through integrated infrastructure access, durable fiscal alignment, and credible local value creation. Western mining companies will break into Africa by pairing capital with partnership, building corridors enabling infrastructure and power, designing credible value addition pathways and operating in a way that is politically durable through transparency, community benefit and fiscal terms that share upside in commodity upcycles. This feature article offers a practical playbook for mining executives and investors. The core argument is straightforward. Winning in Africa requires competing on the full system around the mine. Corridors and power, processing pathways, contract durability, community benefit and regulatory execution are now decisive variables in project valuation and capital access.

Mar 1, 2026