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By W. J. Atkinson, E. M. Anderson

FOREWORD This paper is based on the authors' experience gained in the environmental assessment of major uranium projects in the former Department of Science and the Environment and Department of Home Affairs and Environment of the Australian Government. The authors gratefully acknowledge assistance received from colleagues within the Department of Home Affairs and Environment in the preparation of this paper. Special thanks go to Mr K.E. Thompson of the Department's Environment Division for his valuable comments and criticism. The views expressed in the paper are those of the authors alone and not the Australian Government or Dames & Moore. INTRODUCTION Uranium has been mined in Australia since 1954. A number of small scale mining and milling operations were active in the Northern Territory, in South Australia and in Queensland in the late fifties and early sixties. However, in the late sixties there was an increase in exploration activities in the expectation of an upsurge in world demand for uranium Substantial new resources were delineated in the Northern Territory, Queensland, South Australia and Western Australia. The most significant deposits were located in the Northern Territory, in what is called the Alligator Rivers Region located approximately 200 km east of Darwin. The Region is in the latitude of 13° South and thus lies within the Australian tropics (Figure 1). It consists of approximately 2.3 million hectares of natural wilderness containing much spectacular and attractive scenery. The area is noted for its abundant wildlife, particularly the waterbirds that gather on the flood-plains. Much of the vegetation is diverse and interesting. The Aboriginal population still maintains elements of the traditional way of life, and the spectacular Arnhem Land escarpment contains many of the best surviving examples of Aboriginal rock art. Numerous rich archaeological sites provide evidence of continuous human habitation for tens of thousands of years. Climatically, the Region is of the tropical monsoon type with a dry season from may to September and a "wet" from November to March. High intensity short period rainfall is characteristic, and the average annual precipitation is in the order of 1 350 mm. The monthly mean temperature ranges from 25° to 30°C throughout the year. The development of regulatory controls on uranium mining in the Alligator Rivers Region has been affected by the political status of the Northern Territory. While Australia is a federation, established as an independent self-governing country in 1901, it was not until 1978 that the Northern Territory became to any real extent self-governing. Prior to 1978, the Territory was administered through a special department of the Commonwealth (ie. the Federal Government). Under the Northern Territory (Self Government) Act 1978, administrative powers similar to those possessed by the Governments of the six founding Australian states were provided to the Territory Government. However, the Commonwealth government did not transfer to the Territory all such powers and functions, and in particular there has been, since 1978, a dual role for the Commonwealth and Territory Governments in the regulation of uranium development. Details of this role are provided later in this paper. RANGER URANIUM INQUIRY By 1973, major deposits had been discovered in the Alligator Rivers Region at Nabarlek, Ranger, Koongarra and Jabiluka. The estimated reserves and mine life expectancy of these deposits are given in Table I. Other radioactive anomalies have also been identified in the area but, as yet, they have not been delineated or evaluated. [ ] In 1974, an agreement was signed between the Commonwealth Government and Peko Mines Limited and the Electrolytic Zinc Company of Australia Limited for the joint development of the Ranger deposit. In July 1975, the Government announced a Commission of Inquiry under the provisions of the Commonwealth Environment Protection (Impact of Proposals) Act 1974, into the proposed Ranger development. The inquiry was known as the Ranger Uranium Environmental Inquiry or more commonly, the Fox Inquiry after the presiding Commissioner, Mr Justice Fox.

Jan 1, 1981

By Glenn A. Shirey, Robert D. Stoessner, S. Gopalakrishnan

Under a contract awarded by the U.S. DOE-PETC, the Pennsylvania Electric Company and New York. State Electric and Gas Corporation are conducting a test program to evaluate and optimize the performance of a two-inch air-sparged. hydrocyclone (ASH) for cleaning fine coal. The test program is being conducted at the Homer City EPRI Coal Quality Development Center, utilizing Upper Freeport coal classified to minus 0.15 mm as the process feed material. A matrix of experiments has been conducted to establish the influence of significant design and operating variables (including overflow and underflow orifices, inlet slurry pressure, airflow rate, and reagent dosage) on the production of deep cleaned coal. Performance of the ASH is being compared to conventional froth flotation, utilizing advanced techniques and selected flotation reagents. This paper focuses on work completed to-date to optimize the performance of the air-sparged hydrocyclone for cleaning fine coal. INTRODUCTION The Pennsylvania Electric Company (Penelec) and New York State Electric and Gas Corporation (NYSEG) have been evaluating advanced fine coal cleaning processes for the production of compliance grade coal (1.2 pounds S02/million Btu). Laboratory bench-scale froth flotation results were compared with results of advanced flotation processes as performed by various organizations, utilizing the same coal feed. Among the processes evaluated, the air-sparged hydrocyclone (ASH) - developed by Dr. Jan Miller at the University of Utah - was considered to offer the best potential for retrofitting into an existing coal preparation facility because of the increased capacity per unit volume. The ASH has been shown to process over 100 times the throughput of conventional froth flotation cells. In May of 1988, Penelec/NYSEG was awarded a contract from the Department of Energy's Pittsburgh Energy and Technology Center (DOE-PETC) to optimize the performance of a five cm (two inch) ASH for producing compliance grade coal from raw classified minus 0.150 mm (1.00 mesh) Upper Freeport coal, and to compare its performance with conventional froth flotation utilizing advanced techniques and selected flotation reagents. The test work is being conducted at EPRI's Coal Quality Development Center (CQDC) in Homer City, Pennsylvania, utilizing a circuit processing 0.10 to 0.25 tons of coal per hour. Other members of the Penelec/NYSEG contract team include the University of Utah, Advanced Processing Technologies, Inc., Davy Dravo, Kaiser Engineers, Ebasco Services, and Management and Technical Systems. ASH DESCRIPTION AND OPERATION The ASH-2 System is a five cm ID (actually 4.76 cm) air-sparged hydrocyclone manufactured by Advanced Processing Technologies, Inc., under license from the University of Utah, for the purpose of research, evaluation and development. A schematic drawing of the air-sparged hydrocyclone is presented in Figure 1. Basically the air-sparged hydrocyclone consists of two concentric right-vertical tubes, a conventional cyclone header at the top, and a froth pedestal at the bottom. The inner tube is a porous tube through which air is sparged radially. The outer nonporous tube simply serves as an air jacket to provide for even distribution of air through the porous inner tube. The slurry is fed tangentially through the conventional cyclone header to develop a swirl flow in the radial direction. Air is sparged through the jacketed, inner porous tube wall and is sheared into small bubbles by the swirl flow. Hydrophobic particles in the slurry collide with these bubbles and, after attachment, are transported radially into a froth phase which forms on the cyclone axis. The froth phase is stabilized and constrained by the froth pedestal, thus moving towards the vortex finder of the cyclone header and discharged as an overflow product. Hydrophilic particles generally remain centrifuged in the slurry phase and are discharged as an underflow product through the annulus created by the froth pedestal.

Jan 1, 1989

By Ki Chun

Optimizing ore processing requires a thorough understanding of not only the process itself but the economic constraints which influence business decisions. No single modeling technique is able to model all the different processes running in today's mines. The solution then is to use a number of different model­ing techniques, each competing with the others to best correlate the data. Among these modeling techniques are: Neural Networks, Genetic Algorithms, Fuzzy Logic, Crisp Logic, Statistics, First Principal Models, and System Identification models. Once a model has captured the behavior of the process, a numerical optimization determines the optimal operating point and set point parameters. A single step is then taken in the direc­tion of the optimal location by changing all the process parame­ters to the setting recommended by the optimization system. As the process begins to re-stabilize, the models are updated, the new optimal determined and another step is taken in the direction of the optimum. Through the use of multiple competing models integrated into a numerical optimization the process can achieve the optimal running condition even if the ambient conditions fluctuate dynamically.

Jan 1, 1998

By Sean E. Armstrong, Deepak Malhotra

Gold extraction from refractory ores as a percentage of total gold production is increasing. The processing technology options for treating difficult-to-process refractory ores are also increasing. The best processing option is dependent on many factors including feed grade and the cause for ore refractoriness. The causes for ore refractoriness are many foldCpreg-rob­bing, encapsulation in pyrite, arsenopyrite or silica, presence of cyanocides, presence of cyanide-insoluble gold compounds, etc.1. The first step in the process development of a refractory gold deposit is to determine the cause for ore refractoriness. The traditional approach of undertaking detailed mineralogical examination of ore types, major and minor mineral constituents and their association does not necessarily provide the metallur­gist all the information needed for characterization of gold-bear­ing ores. For process development programs it is desirable to complement traditional mineralogical methods with diagnostic leach testing, which attempts to quantify the deportation of gold in various mineral matrices. This paper briefly reviews the diagnostic leaching proce­dures and its applications for a wide range of gold-bearing refractory ores, both primary and by-product.

Jan 1, 1996

By Richard H. Johnson

The Castle Mountain Mine (CMM) is located in the eastern por­tion of San Bernardino County, Southern California, 70 miles south of Las Vegas. The CMM is a joint venture between Viceroy Gold Corp. (75% and operator) and MK Gold (25%). The CMM initially started gold production with an 8,000 tpd cyanide heap leach operation in February, 1992 when the first ore was crushed and delivered to the leach pads. Even during construction and commissioning, design work was under way to engineer and construct a 1,200 tpd Mill circuit to process the higher grade fraction of the ore through use of pulp agglomera­tion. The need for a grinding circuit became evident with the quantity of high grade material delineated during drilling and the amount of visible gold that the geologists were finding in the drill core and R.C. cuttings. Viceroy did not want to stack the higher grade ore on the heap, and it was clear that permitting a tailings pond would, at best, be a long drawn-out affair. An alternative to a tailings facility had to be found.

Jan 1, 1996

By J. Nelsen

Social License to Operate continues to emerge as a paradigm fundamental to sustainable mineral resources development. It relates to a set of concepts, values, tools, and best practices that represent the view of reality held by each participant (industry and stakeholders). It enables a forum for negotiation through which all parties involved are heard, understood and respected. The exploration phase of the mine life cycle is generally the initial contact with local communities and forms the cornerstone for effective communication and trust building. This paper presents the development of a mineral exploration template, based on field studies, aimed at assisting exploration personnel to establish effective communications and engagement with local communities within a process to build a Social License. The template aims to provide practical assistance in conducting situational analysis - a process of examining and mapping a situation, its elements and their relations - in order to acquire knowledge and understanding of a project, locale and region. Situational analysis is the ?full situation of inquiry?, going beyond just ?knowing the subject? to being fully situated. It forms the initial foundation for a planning process presented in the paper that prepares for a strategy of initial engagement and consultation.

Jan 1, 2007

By M. David Monroe

Getting the best match between truck and haul road requires examining the cost effects of many factors. Most mines use a bottom line measure based on cost per ton of material moved. This measure focuses on the two components of truck haulage cost per ton: productivity (or performance) and operating cost. For specific tasks, productivity can be measured or predicted using either field measurement or modeling. Individual tasks can be combined to provide a larger scale, longer term net figure for total mine output. True cost is more difficult to capture. Factors are time- and task-oriented and can be influenced by a summation of factors over a truck's lifetime. For example, "allocated" costs, such as owning (depreciation) and some repair costs, are spread over long periods. Items such as fuel and tires can be tied more directly to certain tasks. This article focuses on the more direct, task-oriented factors that affect truck productivity and cost. Major factors The relationship of haul roads and trucks means that each must be examined separately to isolate the most important factors affecting performance and cost. There are many factors but the most important are:

Jan 1, 1992

By David J. Dunn

Materials related problems at mines can be big ones - like a newly completed 1 -m (3.5ft) water pipeline burst during initial filling, grinding ball consumption at double the typical norms on startup of a new semiautogenous grinding (SAG) mill circuit or 30 open-pit haul trucks in the shop for new bed liners after less than a year’s service. Materials engineering provides solutions to these kinds of equipment problems by selecting good materials and designs, by trouble-shooting service failures and by maintaining high quality in vendor-furnished materials and components. Materials with good properties, correctly made and fabricated, correctly installed in mining and processing equipment, produce ore and final products reliably and efficiently. Materials engineering, applied during design phases, specification writing, and receipt and installation of materials, ensures that equipment will have the best possible shot at performing up to expectations. Good calls on materials properties - specifying state-of-art materials produced by competent manufacturers - help mine managers to reduce downtime and mining and processing costs. Materials that are improperly made or specified can make a mining operation less efficient or, possibly, uneconomical.

Jan 1, 1992

By James J. Brady, James S. Lewis, Robert B. Gordon, Jimmy W. Honeycutt

INTRODUCTION Tunnel construction has always been an extremely high risk form of contracting primarily due to the inaccessability of information concerning the ground conditions to be encountered during excavation. We certainly make every effort to overcome this problem through borings, geological research, site visits, etc.; but at best owners, engineers and contractors alike are only able to interpolate a relatively small amount of factual data from isolated sections of the project into a forecast of ground conditions for the entire project. In essence this becomes an "educated guessing game" with risk to reward ratios (and subsequently the bid price) in direct relationship to the contractor's confidence in the quality of the guess. In many instances it is economically or physically infeasible to obtain information and of course the total picture is never known until the project is complete. This problem effects the contract format as well as price. The contractor's ability to handle unforseen problems on the project become extremely important as to the project's overall success. The following pages contain an actual case history of a project which affords an excellent example of the entire spectrum of situations resulting from tunnel construction in difficult ground conditions.

Jan 1, 1983

By W. Morgan, D. Gove

In truck and shovel operations, productivity and cost per ton are influenced by the system matching choice, Optimization involves a balance of the size and number of trucks, the size and type of loading tool and the projected material conditions and haul roads. Caterpillar has updated its Fleet Production and Cost program so miners can more easily look at matching choices and optimize on the variable they choose. This paper introduces the Fleet Production and Cost program. It then demonstrates its capabilities with examples of optimization. Mining operations that use trucks need to properly match the number and size of hauling units (trucks, wagons, scrapers, etc.) to a loading unit (wheel-loader, hydraulic shovel-excavator, cable shovel, push tractor, etc.) to provide the best possible fleet match. Optimizing fleet match minimizes the cost per unit of material moved by that fleet. As haul conditions change (haul length, grade or rolling resistance), there may be need to adjust the number of trucks to maintain the optimum fleet match. Fleet Production and Cost is a tool that can be used to optimize the truck-loader match.

Jan 1, 1995

By Robert Stefanko

The importance of underground stress instrumentation cannot be minimized. It was Lord Kelvin who said that unless you can assign a number to a quantity,, you know very little about it. Most engineers will agree although this kind of statement is resented by our friends in non-technical fields. Mining is undergoing a revolution from art to science. But how can mining methods be optimized if there is no way of measuring the effectiveness of a given mining method? Do we know how effective a' support is unless we can determine its reaction to the mine structure? How do we assess the need for modifications to existing systems and supports, and how do we measure the effectiveness of such changes? Cut and try techniques are too wasteful of time and energy, and rarely provide solutions to a given problem. The purpose of underground stress instrumentation is to provide answers to some of the above questions -- answers that cannot be obtained otherwise This does not mean that laboratory studies are not valuable -on the contrary. Laboratory and underground studies supplement one another. Rock mechanics had its conception with the study of stresses in homogeneous, isotropic, and elastic models subjected to various force systems. These analyses were valuable inasmuch as they pinpointed possible sources of trouble due to stress concentrations. If the results observed underground did not always agree with the experimental analysis, it was not an indictment of the latter. More probably, the discrepancy could be attributed to the lack of similitude between model and prototype. The more nearly one can simulate underground conditions in a model, the more apt one is to produce results which correlate well-with underground observations. It is impossible to completely simulate underground conditions because all of the significant design parameters have not been recognized and evaluated. What better way can one evaluate these parameters than by underground stress instrumentation?

Jan 1, 1963

By Neil D. Donnell, O&apos

Ore reserve estimation at the Syncrude Canada Ltd. open-pit oil sands mine in Northern Alberta has evolved since the project's inception. Early techniques followed a conventional petroleum reservoir analysis format, with relatively widely-spaced drill holes and semiquantitative grade data. Experience has developed a more standard mining approach, including classification of geological materials by both lithology and sedimentary origin, timely and multi-purpose drill holes, precise analytical data, empirical recovery factors, a computerized geological data base, and an ore body block model. Future efforts will involve enhancement of existing techniques, use of geostatistical algorithms, quantification of confidence limits, and improved control of the ore model by geological parameters.

Jan 1, 1985

By Richard Stahura

The longtime rule-of-thumb for conveyors was that only one cleaner was needed to solve carryback problems and help keep belt replacement costs under control. That is now being rethought. Belt-cleaning systems manufacturers, designers, and users are shifting to the view that multiple cleaners, placed at key locations on the conveyor and properly maintained, are necessary to solve today's material build-up (carryback) problems. There are still not many statistics on conveyor belt cleaning. But some recent studies support this belief. One study contends that the plant maintenance engineer's biggest problem is keeping the conveyor system running efficiently. The study also said the conveyor itself is responsible for most plant shutdowns. An unscheduled conveyor shutdown can cost more than $100,000/hr and run into millions in lost production in a given year. Other studies pointed out that belt replacement is the greatest single cost of the conveyor system. These studies allude to an important fact: cleaner belts lead to reliability and longer belt life. They showed that a critical relationship exists between characteristics of material being moved and the design of all major conveyor components. In practically all situations this relationship is keyed to belt cleaners, which have long been considered "add-ons" or "accessories." At the Fifth International Coal Utilization Exhibition and Conference, the Sammis Station-Ohio Edison Co. said it installed four belt cleaners on each problem belt. The company found that under certain conditions, when the coal is wet and sticky, carryback can be so heavy that it will flow over two cleaners. Before installing the cleaners, it was necessary to schedule a cleanup crew of four men each day and rent a large vacuum truck for an eight-hour shift. In addition, the company dredged the harbor three times a year, to remove coal spillage. Once the cleaners became operational, however, cleanup costs were reduced to a few days labor every third month. Renting the vacuum truck crew was also eliminated, and harbor dredging became necessary only once each year. In addition, the Mechanical Handling Engineers' Association (MHEA) in London pointed out that standards for cleaners are sorely lacking in the industry. MHEA called for instituting such standards in the future. They also reaffirm using multiple belt cleaners for increased efficiency. MHEA pointed out that some conveyor belts can be cleaned by one device, provided that it is correctly installed and adequately maintained. But MHEA recommended that a system approach be adopted, since this has proved more effective in practice. There are two main reasons why one belt cleaner fails to solve most carryback problems. First, management often reasons that the design of the current cleaner has probably been around for years, so it "must be good." This logic leads to a continued investment in keeping the current model operating, which includes pouring substantial sums of money in "housekeeping" manpower hours because the cleaner does not clean. Second, most single-belt cleaners are specified too late in the design process (indeed, some after the system is operational). This complicates matters since cleaning efficiency is directly proportional to when they are specified: the later the specification, the less efficiency. Cleaning equipment should be taken into consideration before the conveyor's structure is designed and fabricated. Otherwise the space available to install adequate cleaning equipment at the head pulley may be inadequate. Instead of matching conveyor with proper cleaner (as would occur during the design of the conveyor itself), designing a cleaning system "after-the-fact" becomes a matter of matching cleaner to conveyor. This limits choices in cleaners and, therefore, overall cleaning effectiveness. This is why after-the-fact designs of single belt cleaners are costly and rarely successful. While it is always best to specify belt cleaners during early design stages, the multiple-cleaner systems approach makes the timing of cleaner installation less critical. Because of flexible mounting hardware, a well-designed system can lead to 99% efficiency in cleaning and put an end to carryback even after a system is operational. Multiple-Cleaner Systems Approach In a multiple-cleaner system approach, the first step is to achieve a thorough understanding of the material to be moved under the worst conditions. With such un-

Jan 4, 1984

By Mark A. Krall, Robert L. Geddes, James C. Frost

Introduction The Conda Partnership's Dry Valley phosphate mine is a thinly bedded, multiple seam open-pit mining operation where selective mining techniques are used to recover phosphatic shales. The mining methods used are truck/shovel and scraper/dozer operations. Ore is shipped 32 km (20 miles) by rail to a beneficiation facility. The ore is upgraded by washing and calcining. The mine and beneficiation complexes are owned by the Conda partnership. It is a joint venture between Beker Industries Corp., of Greenwich, CT, and Western Co-Operative Fertilizers (US) Inc., of Alberta, Canada. The Partnership operates as a separate entity of the two partners. The Dry Valley mine is located 48 km (30 miles) northeast of Soda Springs in Caribou County in southeastern Idaho. The mine is situated on the Caribou National Forest. Mining operations take place between 2 and 2.4 km (6400 and 7900 ft) in elevation. It is accessible partly by 32 km (20 miles) of paved roads and 16 km (10 miles) of dirt roads. The winters are long and severe, and the summers are short and mild. This article describes the history, geology, exploration, mining, and reclamation that makes this mine Idaho's largest producing mine and the western US' leading phosphate producer. History and production In the mid-1950s, Western Fertilizers of Salt Lake City, UT, drove an exploratory drift in Maybe Canyon. A large bulk sample of phosphatic shales was analyzed for phosphate content and processing characteristics. No large scale mining or processing operations were undertaken. In the late 1950s, the Dry Valley property was sold to Central Farmers of Chicago, IL. No major operations took place. In 1964, Central Farmers sold the property to El Paso Products Co. of Odessa, TX. El Paso Products supervised the mining operations of Wells Cargo Mining Co. from 1965 through 1967. During this time, El Paso Products built a beneficiation facility and a fertilizer complex in Conda. A 32-km (20-mile) railroad was also constructed from the mine to this facility. From 1968 through 1972, the mine was shut down due to a depressed fertilizer market. In 1972, El Paso products sold its ore reserves, beneficiation plant, and fertilizer complex to Beker Industries Corp. In 1979, Beker Industries sold 50% of its ore reserves and 50% of its beneficiation plant to Western Co-Operative Fertilizers (US) Inc., of Alberta Canada, forming the Conda Partnership. It has operated the mine and beneficiation plant since January 1979. From the mid-1950s to the mid-1960s, no substantial production took place. From 1965 to 1967, El Paso Products stripped 3 Mm3 (4 million cu yd) and mined 2.3 Mt (2.5 million st). From 1972 through 1983, 50 Mm3 (66 million cu yd) were stripped and 18 Mt (20 mil¬lion st) were mined. Geology The Wells Formation forms high ridges and hillsides in the Dry Valley area. It is best exposed along the west face of Dry Ridge. It forms the imposing wall on the east side of Dry Valley. The formation is divided into two members. The lower member, about 213 m (700 ft) thick, is dominantly thin to medium-bedded limestone and silty limestone. It contains nodules and stringers of chert and minor sandstone. The upper member is composed principally of thick-bedded to massive cross-bedded, light-gray to orange-yellow, fine grained sandstone. There is some interbedded brown to light-gray limestone. This member varies from 369 to 457 m (1300 to 1500 ft). Recent investigations indicate that the upper Wells is of Permian age. Under some conditions, the Wells may be water-bearing. Otherwise, it has no apparent economic significance. Grandeur Member (Park City Formation) Overlying the Wells Formation is a distinctive light-gray to white dolomitic fossiliferous limestone. This unit has been identified by the US Geological Survey (USGS) as the Grandeur Tongue Member of the Park City Formation. This member is sometimes absent due to its contact with the Meade Peak Member of the Phosphoria Formation. It is easily detectable by its color, hardness, and fetid odor. Phosphoria Formation The Phosphoria Formation of Permian age was named from Phosphoria Gulch, Bear Lake County. The formation has been studied extensively and developed for its economically valuable phosphate reserves.

Jan 11, 1985

By Robert F. Reeves, Stephens A. Avary

Introduction People, systems, methods, and organization make up maintenance productivity. Methods promote efficiency in operations, systems ensure consistency and continuity, and organization maintains direction and control. The common denominator in these techniques, though, is people. Management systems can be technically correct, but fail to work because management systems do not work by themselves - people make them work. Therefore, the foundation for mine maintenance productivity must begin with the people involved. Traditionally, the emphasis placed on mine maintenance, as opposed to production, is not proportional to the impact that maintenance has on a mining operation. The performance and productivity of mine maintenance substantially affects the operating costs, revenues, and profits of the mine. The mining industry has recently experienced a period of economic depression. While it has created financial problems in all segments of the industry, it has caused the industry to focus on the need for improved productivity. Mining companies that have made investments in productivity during this period will have a competitive edge during the recovery, and mine maintenance may be the best place to put that investment. Future lost production and maintenance cost problems can be avoided if mine management has the foresight to seize the opportunities that now exist. Background Technological improvements over the last 30 years have been dramatic in the industry. Before these changes, mining equipment was not very sophisticated. So maintenance needs were not very sophisticated. Maintenance people were not required to have any formal training in mechanical or electrical skills. At many mines there was no formal maintenance organization. The mechanic was a part of the section crew and received direction from the face boss. Mine maintenance was not a function, it was a task. Technological change in mining came about in response to an expanding economy and greater demand for mined products. The past 20 years brought about a change in the kind of individual needed to mine ore and coal, and an even greater change in the person needed to maintain equipment. Equipment went from mechanical and pneumatic to complicated electrical and hydraulic. Maintenance progressed from being a task to being a function. Types of Mechanics Mine maintenance workers can be grouped into three categories based on experience: mechanics with more than 20 years, five- to 10-years, and less then five years. These groupings have influenced mine maintenance productivity. The 20-plus mechanic has been the foundation of the maintenance force. He had no formal training and his skills were acquired on the job. As new equipment was introduced, he learned to repair it by trial and error. Not all of what he learned was correct. Personal initiative and conscientiousness are characteristics of this group. They have experienced the bad times and the good, and appreciate the opportunity to work. The five- to 10-year group worked with the older, more experienced mechanics to acquire maintenance skills. These mechanics came in during industry boom times, and many progressed quickly by being in the right place at the right time. Many in this group have difficulty with diagnostic trouble-shooting, and depend on changing out parts to identify problems. This group is generally more mobile and less apt to have a strong work ethic. Mechanics with about five years experience have vocational training, some formal education or basic skills training. Like the five- to 10-year group, these miners are mobile and tend to move readily to satisfy their changing needs. These two younger groups are less apt to feel any loyalty to the employer or obligation to be productive. Their attitudes and abilities reflect the influence of their general age groups, and has a definite impact on mining productivity. Past Requirements In the 1960s, the basic requirements for a maintenance supervisor was that he be a top mechanic, get along well with the men, and be a hustler and improviser. He learned the details of new equipment as repairs were needed. Oftentimes, this individual would be the only person on the property with the ability to read prints, use diagnostic testing equipment, and troubleshoot using an analytical approach. This approach to maintenance is sufficient when the equipment design is reasonably uncomplicated. Management Changes As technology progressed, organized labor gained strength, government regulation increased, and the job of supervising and managing people had to change. The environment has changed and

Jan 11, 1983

By Alan English

This paper reviews the process control systems used in early commercial pelletizing plants, traces the development of these systems into present day practice, and briefly outlines advanced automation concepts being considered for future installations. It deals specifically with controls for the balling circuit, pelletizing machines, and related material handling and combustion equipment. The importance of instruments for visual observation and data logging is discussed, and the potential use of computer control is evaluated.

Jan 1, 1965

By K. Brady

Making progress on sustainable development will require greater attention to the management of materials produced from mine exploration through use to reuse, recovery and recycling. Material stewardship is a concept that embodies the range of activities required for optimal and appropriate use of minerals and metals in society. The following paper provides an overview of some recent initiatives that promote the stewardship of minerals and metals in society. The initiatives described are being conducted by organisations ? the International Zinc Association, the Canadian Copper & Brass Development Association and the International Council on Mining & Metals. These associations illustrate stewardship activities at three different levels: - an international association representing companies that produce a range of minerals and metals; - an international commodity association; and - a regional association. For each initiative, information is presented on its development, scope and outlook. This paper draws heavily from work of the associations but the viewpoints are the responsibility of the authors.

Jan 1, 2007

By Mark E. Smith, Gerald J. Gierszewski

Introduction The purpose of this paper is to present a procedure used by the authors for evaluating and designing soil liner systems. This method is particularly valuable in evaluating various treatment schemes for chemically amended soil liners. A tabulation of laboratory test results on various soil types are presented to quantify the effectiveness of certain treatments. A typical liner design program includes developing and proving soil borrow sources, designing the cross-section of the liner system, developing construction specifications, and providing construction services to ensure the intended product is achieved. Material Source Development The first step in designing a soil liner is to identify and evaluate suitable borrow sources within an economical haulage range. This is best done in a two step approach: a reconnaissance level investigation to identify target areas and a detailed evaluation of those targets. Reconnaissance: The goal of the preliminary investigation is to locate potential borrow sources for liner quality soils. This includes all natural materials which can be compacted, chemically treated, or otherwise amended to yield an installed permeability at or below some target value. This requires utilization of all available data sources: Soil Conservation Service, BLM, aerial photos, USGS geologic maps, and project geologist records. The goal at this stage is to locate shallow deposits of favorable soil types. The Unified Soil Classification System provides an excellent first pass grouping. Clays, clayey sands and silts are the most favorable soil types, although silty sands and occasionally clayey gravels can make excellent liners, and are often amenable to chemical modification. The lowest permeabilities are generally achieved with CH, CL and MH soils. Once preliminary targets have been identified using visual examination, laboratory classification tests should be performed to further refine the selection. Testing at this stage should include gradation, plasticity and hydrometer analyses. Additionally, "preg-rob" testing should be done as early as practical. Preg-rob is a phenomenon where gold or silver ions in solution associate with the clay, or other, minerals. When this occurs, a portion of the gold or silver leached from the ore is actually tied-up by the clay and thus a reduces recovery. Testing for this consists of agitating a small sample of the soil in a solution containing dissolved gold or silver, preferably of similar chemical make-up as the solution which will contact the actual liner. The solution and soil are assayed before and after agitation to determine loss to the clay. A reliable estimate of the hydraulic conductivity, commonly referred to as permeability, can be developed from the D10 value by the use of Hezen's formula: K = 100 (D1012 This relationship is limited to soils where the finer particles do not move due to the force of flowing water (i.e.: "hydrodynamic stabilitym)(1). Additionally, the effect of platty particles on permeability is not as predictable as the effect of equidimensional particles. D10 is the sieve opening size at which 10% of the material is finer. Plasticity is also important from several standpoints. Constructability is directly related to plasticity. Very plastic clays and non-plastic silts both tend to be difficult soils, while medium plastic clays and clayey sands are generally very desirable. Post construction performance is also related to plasticity (e.g. swelling, shrinkage cracking, frost heave, etc.). Additionally, low plasticity silts and silty sands generally do not respond well to chemical amendment. Source Development: The result of the reconnaissance evaluation should be an estimate of the relative probability of developing a suitable borrow source within an economical haul distance. Of course, "economical distance" depends on the degree of handling and treatment the borrow material requires, as well as the cost of synthetic alternatives. The purpose of the detailed investigation is to prove out quantity and quality of material sources, and determine design parameters such as degree of compaction, mixing, treatment and thickness of liner. The emphasis of the testing program should be permeability and strength. Strength becomes increasingly important as the slope of the liner and the height of the heap increase. Permeability testing should evaluate the effects of compaction, water content, mixing and chemical treatment where appropriate. The effects compaction and water content during compaction have on

Jan 1, 1987

By Edmund J. Flynn

My subject Is Industrial Relations. Thus, I may appear as an intruder at this annual meeting of the Society of Mining Engineers. But I am no more an intruder here than is Industrial Relations in the day-to-day functioning of an engineer either in a staff or a line job. Engineers deal with people, as well as with blueprints, organizational charts, production data, etc. Where you have people, you have emotions, gripes, wants - real or imagined. Or you may just need some people or, at the other end of the pole, you may want to free yourself of people. But whether it is the wants or the needs, the pleasant or the unpleasant aspects of dealing with people, an Industrial Relations Department within an organization is there to help with these human relationships. This is the point for a definition of terns. Reference has just been made to "dealing with people? and to "human relations." This is, precisely the area in which Industrial Relations operates in the western Mining Divisions of Kennecott. In other organizations, what we refer to as Industrial Relations, may be called personnel relations, personnel administration, employee relations, or labor management relations. In our opinion the term Industrial Relations is best descriptive of the activity because it embraces the broad field of human behavior, reactions and satisfactions growing out of an individual?s entire employment relationship including his hiring, his lifetime on the job, and his termination. This is an individual?s industrial life. However, despite the use of the word "industrial", we are ever conscious that Industrial Relations is limited to human relations. Operational activities and decisions relating to the mining, milling, smelting and refining processes are for the line organization. The Industrial Relations interest in these line organizations activities and decisions relates only to the impact they nay have on employees - on people generally within the organization.

Jan 1, 1959

By David Oliveira

"INTRODUCTIONOne of the key drivers for the selection of a mechanized tunneling method in good quality rock masses is a good excavation advance rate. In order to achieve satisfactory advance rates, a good geotechnical performance of the rock grippers in main beam open tunnel boring machines (TBM) is required, besides other factors related to ground support and the performance of the cutter head.One well known potential issue of main beam gripper TBM is associated with the bearing capacity of the tunnel side walls while crossing fault zones or poor rock masses in general. Such a mechanism is similar to that of footings on rock and perhaps the most common problem associated with gripper performance. Depending on the quality of the rock, the rock under the gripper contact may experience significant damage and crushing (Figure 1), eventually affecting the TBM advance rate due to a lack of tunnel wall reaction/support. Such a mechanism is primarily dependent on rock quality, applied loads and gripper size.In the case of large diameter TBMs (e.g., D > 12 m), a second potential failure mechanism may arise associated with the loss of confinement within a rock pillar between twin tunnels, even in good quality rock but particularly in bedded sedimentary strata. Punching of the rock pillar may develop due to excessive shear along bedding partings and sub-vertical joints (Figure 2), particularly under a low stress environment. As a result, this mechanism is dependent on both the rock pillar width between twin tunnels and stress conditions around the tunnels, in addition to the previous factors described for the first failure mechanism."

Jan 1, 2016