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By Robert B. Fulton, Gill Montgomery

Fluorspar is the commercial name for fluorite, a mineral that is calcium fluoride, CaF2. The name, derived from the Latin word fluere (to flow), refers to its low melting point and its early use in metallurgy as a flux. It is the principal industrial source of the element fluorine. Two other minerals, cryolite and fluorapatite, have significant fluorine content. Cryolite, sodium aluminum fluoride, Na3AlF,, is a rare mineral that has been found in commercial quantities only in Greenland. The natural material has been supplanted by synthetic cryolite for its principal industrial use in the manufacture of aluminum. Fluorapatite, Ca5F(PO3)2, is a source of phosphate for fertilizer manufacture, containing a small percentage of fluorine. Commercially mined deposits of apatite have varying amounts of fluorine, chlorine, hydroxyl, and carbonate. HISTORY Fluorspar was used by the early Greeks and Romans for ornamental purposes as vases, drinking cups, and table tops. Various peoples, including the Chinese and the American Indians, carved ornaments and figurines from large crystals. Its usefulness as a flux was known to Agricola in 16th century Europe. Fluorspar mining began in England about 1775 and at various places in the United States between 1820 and 1840. Production grew substantially following the development of basic open hearth steelmaking, wherein it is used as a flux. Use was stimulated by growth of the steel, aluminum, chemical, and ceramic industries, particularly during World Wars I and 11. Fluorocarbons entered the picture in 1931. The use of anhydrous hydrogen fluoride (HF) as a catalyst in the manufacture of alkylate for high octane fuel began in 1942. Differential flotation for separating fluorspar from galena, sphalerite, and common gangue minerals in the 1930s and the application of heavy media concentrating methods to the treatment of low grade ores in the 1940s were outstanding technological advances that facilitated increased production. Pelletizing and briquetting of flotation concentrates for use in steel furnaces and the development of flotation schemes for beneficiating ores containing abundant dolomite and barite have been major improvements in the industry. USES OF FLUORITE Fluorspar is used to make hydrogen fluoride (HF), also called hydrofluoric acid, an intermediate for fluorocarbons, aluminum fluoride, and synthetic cryolite. It is used as a flux in the steel and ceramic industries, in iron foundry and ferroalloy practice, and has many minor specialized uses. Hydrogen fluoride is produced by reacting acid grade (97% CaF,) fluorspar with sulfuric acid in a heated kiln or retort to produce HF gas and calcium sulfate. After purification by scrubbing, condensing, and distillation; the HF is marketed as anhydrous HF, a colorless fuming liquid, or it may be absorbed in water to form the aqueous acid, usually 70% HF. Synthetic cryolite, organic and inorganic fluoride chemicals, and elemental fluorine are made from hydrofluoric acid. The acid itself is important in catalysis in the manufacture of alkylate, an ingredient in high-octane fuel for aircraft and automobiles; in steel pickling, enamel stripping, and glass etching and polishing; and in various electroplating operations. The manufacture of one ton of virgin aluminum requires about 12 to 29 kg of fluorine content in synthetic cryolite and aluminum fluoride. This quantity, through improved technology and recovery practices, is being lowered significantly in countries with the most advanced technology (i.e., Australia and Sweden), while others (i.e., Surinam and South Africa), remain at the high end. Elemental fluorine is prepared from anhydrous hydrofluoric acid by electrolysis. Gaseous at room temperature and pressure, fluorine is compressed to a liquid for shipment in cylinders or in tank trucks. Elemental fluorine is used to make uranium hexafluoride, sulfur hexafluoride, and halogen fluorides. Gaseous uranium hexafluoride is used in separating U235 from U233 by the diffusion process. Sulfur hexafluoride is a stable high dielectric gas used in coaxial cables, transformers, and radar wave guides. Halogen fluorides have important applications, mostly as substitutes for elemental fluorine, which is more difficult to handle. Emulsified perfluorochemicals, organic compounds in which all hydrogen atoms have been replaced by fluorine, are undergoing investigation as promising blood substitutes. They transport oxygen and, in conjunction with a simulated blood serum, perform many functions of whole blood. With further development, these organic compounds may ultimately, in emergencies, be useful in saving lives of animals and humans during periods of acute shortages of natural blood. Inorganic fluorides are used as insecticides, preservatives, antiseptics, ceramic additives, and fluxes and in electroplating solutions, antioxidants, and many other products. Boron trifluoride is an important catalyst. Organic fluorides are volume leaders in the fluorine chemical industry. Fluorinated chlorocarbons and fluorocarbons are prepared by the interaction of anhydrous HF with chloroform, perchlorethylene and carbon tetrachloride, and are characterized by low toxicity and notable chemical stability. They perform outstandingly as refrigerants, aerosol propellants, solvents, and cleaning agents and as intermediates for polymers such as fluorocarbon resins and elastomers. Fluorocarbon resins are inert compounds that have unusually low coefficients of friction and have found a number of applications as lubricants for parts that cannot be oiled, e.g., bearings for window raising equipment located inside of automobile doors, in small electronic equipment, for the manufacture of chem-

Jan 1, 1994

By Dal Negro Enrico, Andrea Picchio, Boscaro Alessandro

"The Doha Metro Project is one of the most relevant ongoing tunneling projects. The whole project consists of about 100 km of tunnels with 21 EPB TBMs working in the same period. Due to the variability of the geological formations, the soil conditioning is a relevant aspect of this project because the parameters should be frequently adjusted to achieve the best performances of the TBMs. The study of the soil conditioning has been carried out accurately to obtain the best results on site. The study of the geotechnical data, the choice of the most suitable foaming agents and polymers and the laboratory study of the soil conditioning has been a fundamental part of the job. The application of the soil conditioning products on site with the analysis of the TBM data have confirmed the preliminary study results with some correlation between the features of the ground and the soil conditioning parameters to be used. INTRODUCTION Phase 1 of the Doha Metro Underground project is composed by 3 lines able to bring passengers to all the points of interest in the Qatar capital city. The Red Line, also called coastal line, connects the north of the city to the south, and to the new Hamad International Airport, following the coast line. The Golden Line, called Historic Line, will connect the southern area of Doha to the “Aspire zone” the area of the city where many state of the art sport centers are located, passing through the old city center. The Green Line, named education line, will connect the old city center to the Doha Education City. All the lines are realized with 2 tubes, single track. The whole underground project is realized with 21 TBMs, excavation diameter of 7.10 m. The project has been divided in 4 packages, for a total excavation length of more than 100 km. The need to underpass roads, existing buildings, and to excavate, in some areas, at less than 100 m from the coast line, forced the choice of a tunneling system with Earth Pressure Balance (EPB), that involves in the project another fundamental aspect of this tunneling system: the soil conditioning. The soil conditioning has multiples functions in the EPB system such as to make the soil suitable to properly apply the pressure on the tunnel face and to be extracted effectively with the screw conveyor. To properly study this topic it was necessary to study the geological formations to be excavated, the hydrogeological conditions of the underground, the foam injection systems of the EPB TBMs and to perform specific tests to evaluate a suitable conditioning to be verified and adjusted during the real scale application."

Jan 1, 2016

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 C. J. Bise

Virtual reality (VR) is a concept in which the human experience of perceiving and interacting with a computer-modeled environment is achieved through the use of sensors and effectors. It is an advanced form of computer graphics. The images are generated based on where the user looks and how the user moves. As personal-computer-based (PC) instruction gains acceptance as an innovative approach to providing safety training, VR can provide a multisensory, rather than merely a multimedia, mode of presentation. New technology continues to be introduced into the mining industry to meet the productivity needs of coal and noncoal producers. There is also an increased need for more innovative training of mine workers. New technology and equipment designs often affect the basic causes of accidents. For example, the development of cabs and canopies for underground coal-mine equipment has reduced the number of accidents related to roof falls and rib rolls. However, safety-training specialists then had to focus on the machines themselves, because the modifications had the potential for causing "pinch-point" accidents. In fact, although the overall physical demands on mine workers have diminished, there has been an escalation in the concerns about trauma from repetitive physical activity. Thus, health-and-safety training specialists have shifted their atten¬tion to the recognition, evaluation and control of workplace hazards (Hancock and Hill, 1995). Recognizing that the spatial relationships of a workplace convey more information about hazards when experienced rather than described, trainers agree that simulation is the method of choice. Unfortunately, until recently, simulation systems were either simple software programs that did not come close to portraying the real experience or were complex hardware systems (such as flight simulators) that did, but at a cost of millions of dollars (Fritz, 1991). However, researchers and training specialists are excited about an emerging approach to work-force education based on virtual reality. VR is also described as cyberspace, immersive simulation, artificial reality, telepresence, virtual environment or virtual world (Meyer and Dunn-Roberts, 1992; Peterson, 1992). It represents a group of concurrent advances in computer and interface technologies. They enable an individual to interact in a multisensory way with a computer-generated environment. To achieve this, a typical VR system incorporates a computer that contains the necessary databases for producing realistic images and audio; a head-mounted display (HMD) or screen for viewing the images; and a three-dimensional controller, joystick or data glove for interacting with the computer-generated environment. If virtual reality is to become an effective tool for the safety training of mine workers, its attributes will have to be measured against other forms of delivery. Accordingly, Carr (1992) listed the following areas in which VR should be considered the method of choice: ? When training mistakes would be costly. ? When the necessary environment cannot be experienced in the real world. ? To build interfaces that are sensible and can be manipulated. ? To make training situations really "real." ?To make perceptible the imperceptible.

Jan 1, 1997

By Dale R. Ralston, Roy E. Williams, Gerry V. Winter, George L. Bloomsburg

GENERAL STATEMENT Data frequently can be collected by several dif¬ferent methods. The method required for the nec¬essary precision for inflow prediction to mines should be selected and other methods avoided. Pre¬cision monitoring or measuring techniques fre¬quently require more time, expertise, and expense in their implementation that may not be justifiable. The temporal distribution of the data needs also may dictate the method used for data collection. Continuous recording devices may be required for time sensitive data whereas point measurements of other parameters may be adequate. Data needs will vary as the hydrologic investigation proceeds. In¬itial data needs may require only a qualitative col¬lection of data such as the areal distribution of precipitation. Subsequent data needs may require the measurement of ground water levels to the near¬est hundredth of a foot. Data requirements can be difficult to fulfill for ground water systems. This is particularly true for anisotropic, heterogeneous hydrostratigraphic units since the hydrogeologic parameters vary both ver¬tically and areally. Techniques exist for determining the storage characteristics of both unconfined and confined hydrostratigraphic units but these pro¬cedures require the installation of multiple wells in the same unit which may be impractical. Specific tests are discussed subsequently that permit the determination of vertical hydraulic conductivity. Data collected from field procedures or tests are generally preferred to laboratory derived data. This is especially true for hydrogeologic parameters such as hydraulic conductivity. SURFACE WATER SYSTEMS Precipitation Precipitation data can be collected from sources that maintain a historical record. The US Depart¬ment of Commerce, National Oceanic and Atmos¬pheric Administration (NOAA), maintains weather observation stations across the country. Such a sta¬tion frequently can be found near a proposed mine site but the type of weather data collected varies from station to station. Fortunately, precipitation data are collected ubiquitously. The data collected by NOAA can be purchased for the area of interest in the form of monthly and annual tabulations. Private weather stations constitute a second source of precipitation data. Existing data usually are analyzed by one of three methods. The station average method merely sums the depth of precipitation at each station and divides the sum by the number of stations as fol¬lows: [ ] where Pavg is the average precipitation (L), P, is the depth of precipitation at station i (L), and N is the total number of stations. This method is applicable where there are a relatively large number of stations uniformly distributed across the area (Hjelnfelt and Cassidy, 1975, pp. 71-72). The second method, called the Thiessen poly¬gon method, weights the precipitation at each sta¬tion in direct proportion to the area it represents without consideration of topography. The stations are plotted on a map and perpendicular bisectors are drawn on the lines connecting the stations. The polygons formed by these bisectors constitute the area that the precipitation for that station repre¬sents. The overall precipitation can be calculated with the following equation:

Jan 1, 1986

By Gill Montgomery

Although fluorspar is considered an industrial mineral by usage and value, its geological occurrence and the mining and milling methods employed make it more akin to the non-ferrous metal ores. Likewise methods of exploration for it are more like those used in the search for lead and zinc, with which fluorspar is often mixed. In fact, it often takes the mixture of fluorspar, lead, zinc, plus maybe barite to add up to enough recoverable values to make the mineral an ore by definition. This is so true where the fluorspar portion is low grade, perhaps less than 25 percent. Until the development of modern steel milling in World War I times, the invention of aluminum smelting, and development of the fluorine chemical industry and air conditioning, there were few uses for fluorspar aside from ceramic fluxes in the flint glass industry and for uses as glazes for pottery and china. Pure fluorite crystals have long been admired as semi-precious and ornamental minerals of many delicate colors.

Jan 1, 1983

By James L. McGregor

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

Jan 1, 1960

By E. Topuz

Productivity is the most important determinant in the economics of underground coal mining operations. Lower labor productivity increases labor requirements per ton. This, in turn, increases the unit cost of production. Intensive labor requirements may also affect miner injuries and fatalities by increasing man-hours of exposure necessary to produce a given amount of coal.

Jan 1, 1988

By R. Todd Swinderman

Variations in designs between belt cleaner systems are so wide that it is impractical to establish a dimensional stan- dard. The number of variables that affect the efficiency of belt cleaners is too great to assume a required number or style of cleaners for broad classifications of bulk solids or typical applications. The amount of carryback remaining on the belt is more dependent upon the characteristics of the bulk solid and the physical parameters of the conveyor system than it is on tonnage of material conveyed. Therefore, a performance-based standard is proposed. Three levels of cleaning performance are proposed: • Level I cleaning is general specified when concerns about carryback are not critical. Cleaning systems normally associated with achieving a Level I performance are single or double cleaner systems with one-piece blades undergoing poor to average maintenance. Frequent cleaning of the carryback that falls from the return run will likely be required. • Level II cleaning is generally specified when carry- back is of concern but does not create a safety or environmental problem. Cleaning systems normally associated with Level I1 performance are multiple cleaner systems with segmented blades undergoing the manufacturer's specified maintenance. Regular but infrequent cleaning of the carryback that falls from the return run will likely be required. • Level III cleaning is generally specified when con- cerns about carryback are critical. Concerns range from safety to environmental to product contamination. Cleaning systems normally associated with achieving a Level 111 performance are multiple cleaner systems in conjunction with at least one low- volume water spray. Scheduled inspection and the manufacturer's specified maintenance would have to be performed to maintain a high level of cleaning performance. Difficult-to-clean bulk materials may require the use of a washbox system with multiple cleaners using a combination of low-volume eater sprays to lubricate the cleaners and high-volume sprays to keep the washbox and discharge piping freely flowing. Further addition of a water and sludge recycling system reduces the amount of water that ends up in the product to a negligible amount. Very infrequent cleaning of the carryback that falls from the return run will be required. PURPOSE The purpose of this proposal is to propose a standard method for specifying belt cleaner systems based on user expectations and equipment performance over time. DEFINITION In bulk solids handling by conveyor belt, carryback is the material that adheres to the belt after the belt discharges its cargo. PROPOSED STANDARD Required Basic Good Practices There are a number of basic design and operating principles that are good practice for the selection, installation, and maintenance of belt cleaning systems on conveyors in order to achieve "standard belt cleaning performance over time. 1. The Belt Cleaning System shall be designed to meet the performance requirements based on the worst operating conditions and worst bulk solids proper- ties that are expected. 2. Each conveyor discharge point shall be designed to readily accept the manufacturer's recommended minimum number of belt cleaners. In addition, the discharge chute shall be designed to accept, with minor modifications, at least one additional cleaner if it is required.

Jan 1, 2004

By Dale W. Norris

United States Steel's Cumberland Coal Operations is located in Greene County in the southwest corner of Pennsylvania. The mine and related facilities have been in operation since September of 1977. Production from this mine, U. S. Steel's first commercial coal mining venture, will eventually reach a level of 2.72 million mt of clean coal per year and is totally committed to electric power generation. Cumberland is a slope mine in the Pittsburgh seam and is mined by continuous mining machines and longwall. The coal from the mine is trans- ported by belt to the surface, taken through a rotary breaker for initial preparation, and stored in raw coal silos. It is then processed through the preparation plant and taken to a clean coal silo where it is held for train loading. Cumberland Mine operates its am 28.16 km railroad to transport the coal to the Monongahela River. The unit train consists of thirty-one 90 mt cars. The coal, once loaded on barges, is then shipped to the customer. Cumberland Mine is one of the most modern coal preparation and unit train loading systems in the nation. The preparation plant is de- signed to receive coal from the silos at a rate of 720 at per hour. The +6.35 mm material is screened out and cleaned in a Daniels heavy media vessel with two 3.35 m weirs. Minus 6.35 mm material is fed to sixteen #88 Deister concentrating tables. The cleaned coal from this circuit is dewatered, and all effluents from the mechanical dewatering report to the classifying Cyclone sump for classification through ten 35.6 cm cyclones. The cyclones overflow material (-150 mesh) is processed through two banks of three 8.5 m3 Denver D.R. flotation machines. The cyclone underflow pro- duct (28-1 0 mesh) is processed in two banks of 5 six 2.83 m Denver Sub A machines. The clean flotation product is then dewatered in Bird screen bowl centrifuges, blended with the other clean coal size fractions, and the total plant product further dewatered in a thermal dryer.

Jan 1, 1980

By M. K. McCarter

INTRODUCTION Mining activity and basic geometry of open pit mines represent major obstacles in geotechnical mapping. Mining creates a constantly changing topographic base which may require corresponding updates of field sheets before mapping can proceed. The rapid pace of mining operations may also threaten removal of important geologic and engineering features before adequate base maps and surveyed control can be established. Maintaining such control during the mapping process is yet another complication. In addition, basic geometry yields nearly vertical outcrops. Access required for direct observation and measurement, essential to conventional plane table or Brunton techniques, may be impossible on such surfaces. Also, nearly vertical surfaces appear fore- shortened in plan view. This reduction in area provides little room for recording geotechnical detail. The difficulties encountered in open pit mapping can be substantially reduced by utilizing a modified form of plane table photogrammetry. This technique employs photographs taken from the ground as the base upon which details are recorded. The information is later transferred to plan maps using the plane table principal of location by intersection (Davis and Foote, 1953). Any change in topography can be accommodated by simply taking additional photographs. Proper spatial representation in plan view can be determined later when updated maps and surveyed control are available. In addition, horizontal photographs from the ground portray vertical surfaces as they are normally viewed thus providing maximum area for recording details. Any detail which can be identified on the photograph can be located correctly even though the actual feature is physically inaccessible. The technique presented in this paper was developed by the author for special applications at Kennecott's Bingham operation in 1970. The procedure was rapidly adopted for general use and has proven to be a practical tool for detailed investigation of potentially unstable areas (Zavodni and McCarter, 1976) and routine geological mapping (Richardson, 1975). Major advantages, other than those mentioned above, include: The speed and accuracy are greater than for conventional plane table or Brunton methods. The photo- graph represents a view from a station at some distance from the area being mapped. This vantage point allows evaluation of possible continuity of structures from one level to another which may not be evident at close range. The photographic base provides a permanent record of the topography at the time

Jan 1, 1977

By John E. Miller

In recent years there has been increasing concern in the mining industry over the availability and high cost of diesel fuel to support mining operations. Unit Rig & Equipment Co. has been deeply involved with the development and testing of the newest designs for trolley assist. Beginning in dune 1980, Unit Rig modified and commissioned six 156 metric ton (170 short ton) trolley assist haulage trucks at two mine locations in South Africa. Operating haulage trucks with General Electric GTA 15E/776 drive systems were chosen for the tests since this size of truck represented the majority of the population of large size haulage trucks and the greatest technical development problems. Test operations have proven the feasibility of equipment designs in actual operation and preliminary economic data has convinced the operators to proceed with planning to modify their entire mining operation to use trolley assist. The initial capital investment incurred for trolley assist can be recovered in a short period of time. Following this quick capital recovery, mines will continue to realize lower operating costs through increased productivity and lower diesel consumption.

Jan 1, 1980

By Sheldon P. Wimpfen

SHELDON P. WIMPFEN The measure of the success of any mining operation is the size of the difference between sales realization and cost of product, including operating, sales, administra¬tive, capital and others. Evaluation of a mining project necessitates projecting costs and sales realization as accurately as possible. Possible variations in specific cost elements and sales prices must be considered. To accomplish this, project studies should include giving effect to possible fluctuations to determine the break¬even points with varying costs and prices. Development of cost data is never an easy task. Mining is characterized by a great variety of conditions which result in still more variables. Achieving realistic figures as of any specific time involves consideration of changes, which may be frequent, in labor-contract terms and equipment used, variations in working condi¬tions and mining practices, and changes in mineralization and metallurgy. The purchasing power of the dollar, which has been declining persistently, also affects the situation at any given time. The only thing that can be said of costs, with certainty, is that they will change. With this in mind, the "guideline" data in this section are offered for the use of the mining engineer. It was provided for the most part by representative companies, whose contributions are gratefully acknowledged. In reviewing the tabu¬lations and other material it is of course necessary to remember that the data presented are valid only for the time periods specified, and will change with changing economic conditions in any other. 31.1-CAPITAL COST OF PLANTS Plant capital costs are set forth in Tables 31-6 and 31-7 by year of construction. To estimate capital cost of plants built in future years, various cost bases and indexes are utilized. Design and Construction Manpower: Monthly Salary Ranges, January, 1970 Project manager $1,400-82,600 Project engineer1,000- 1,500 Project design engineer1,050- 1,800 Senior engineer1,000- 1,700 Senior design engineer1,100- 1,700 Senior engineering designer1,000- 1,300 Layout draftsman750- 1,000 Detail draftsman650- 1,000 Material engineer900- 1,400 Construction-project manager1,500- 2,500 Project engineer1,500- 2,500 Construction superintendent 1,500- 2,500 A rule of thumb in design work is one man-month per drawing. The number will vary for each specific plant. For a recently constructed 30,000-tpd (tons per day) copper concentrator, 1,800 drawings were made. Design should provide for the addition of milling units when these may become justified in relation to investment markets and life of the deposit.

Jan 1, 1973

By James Stewart

"THAT WHICH WE CANNOT SEE" INTRODUCTION Often it has been stated that the greatest of all fears is fear itself - fear created only by that which we cannot see or by that which we fail to understand. The elimination or minimization of fear can best be accomplished by a thorough understanding of the underlying causes of the fear. As related to the mining industry the omnipresent fear is the dread of acquiring cancer through accumulated exposure to "that which we cannot see" - radioactivity. The understanding of the resulting exposure effects can best be obtained through acquisition of authentic data and the subsequent analysis of the same by a group of highly qualified specialists. I may point out that the nuclear industry and its source, uranium mining, greatly surpass any other industries in the degree of public awareness as to its potential environmental effects. Public out-cry has always influenced major decisions relating to how industries conduct their operations and much of their effort has resulted in many changes. The issues of health and safety in the mining industry have created considerable public concern, but intense concern to those of us directly involved within the industry. Increasing concern regarding the effect of human activity on the quality of the outer environment of air, land, and water has developed within the past two decades. There is now a growing concern about the health and safety of persons at work in their inner environment, of their working-places in industry. Hearings and investigations conducted in Canada by three appointed "Royal Commissions" have all confirmed that this concern is well justified when focused on the health and safety of workers in our mines. REGULATORY CONTROL OF URANIUM MINING OPERATIONS In Canada, the ownership of mineral resources and the control of their extraction, except for uranium, is vested under the "British North America Act" in the provinces. In all provinces the statutory basis for health and safety provisions in the mining industry can be found in the provincial "Mining Acts" with each province assuming the responsibility to produce its own "Mining Act". In particular, all of the Mining Acts in Canada place upon the management of a mine the responsibility to ensure that provincial provisions are met. The "Federal Register" and mining companies parallel this arrangement in the United States. Equivalent legal

Jan 1, 1981

By Adam Bedell, Jack Raymer, Brad Crenshaw

Tunnel contracts often include provisions for pre-excavation probing and grouting for areas ahead of the tunnel heading. If grouting triggers are met, tunneling stops, and grouting is performed. There is substantial variation within the underground industry on what criteria are applied to the grout verification hole that is drilled post-grouting and before excavation resumes. The criteria for determination of the effectiveness should be dependent on the geology and local hydrogeologic conditions. The purpose of this paper is to present specific criteria that can be used by a practitioner to determine whether tunneling can resume or if additional grouting is required.

Dec 1, 2022

By T. W. Mattioli

Restrictions on fugitive emissions and crushing operations continue to get tighter. Although fugitive dust control in the gold mining industry has historically been difficult, there are now several options that can make dust control both effective and efficient. Using new technology, mine operators can now design and maintain a dust control program that can reduce product losses, decrease equipment failure, cut cleaning costs, and meet air quality compliance standards as well as provide a better working environment. This paper discusses the sources of fugitive emissions related to the gold mining and crushing operations and describes effective new control methods.

Jan 1, 1998

By Michael J. Martinson

Mine ventilation has been evolving as a separate field of study since the middle of the nineteenth century, and some practitioners might assert that mine ventilation has come of age as a discrete field in the last decade or two. Certainly the extensive literature now available on many facets of the subject, international congresses, the phenomenal upsurge of interest in mine ventilation in the United States of America since the passage of the 1969 Federal Coal Mine Health and Safety Act, and the existence of a virile mine ventilation society in South Africa with its own monthly journal all point in this general direction; on the other hand the lack of a rational design philosophy for ventilating mines suggests that mine ventilation may still be on the threshold of maturity. To generalise, many mines are still ventilated simply to comply with arbitrary statutory regulations, or with some ill- defined notion of reducing the risk of injury associated with the atmospheric environment in mines. Hazards in this category include oxygen deficiency, toxic gases and particulates, pathogenic gases and aerosols, explosive gases and dusts, and extreme climatic conditions. Although many mines are ventilated to abate the risk of a specific injury, there is inevitably a spectrum of latent and patent atmospheric hazards in every underground mine. The writer (Martinson, 1976) has previously drawn attention to the dearth of material on mine ventilation design in textbooks and technical journals, and to the overly simplistic approach sometimes adopted in the limited work published on the subject. The available material undoubtedly contains useful technical data and persuasive views, but seemingly could not be used to demonstrate the rational engineering approach to mine ventilation design advocated in the present paper. The range of papers presented at the 1975 and 1979 Congresses, and the diverse interests and affiliations of delegates, emphasize the multidisciplinary nature of mine ventilation. Easily recognisable topics include: Fluid mechanics Thermodynamics Heat transfer Flames and combustion Aerosol physics Radiation physics Geophysics and geomechanics Occupational diseases Epidemiology Industrial physiology Despite these heterogeneous connections there can be little doubt that mine ventilation is fundamentally an engineering field and not an off-shoot of some other branch of applied science. The distinction is important because mine ventilation has essentially developed as a form of ad hoc trouble- shooting, and in the process mining engineers have relied extensively on the assistance of experts drawn from other fields. Thus historically there has been limited scope for the application of rational design techniques, and personnel enlisted from scientific disciplines may not have had any previous experience in the intricacies of engineering design.

Jan 1, 1980

By C. Fuellenbach, J. Brune

"INTRODUCTION Mining activities must be safe and profitable. These two requirements influence each other. The purchase and implementation of safety improvements costs money. Injuries and illnesses at mines stop or delay production and may result in additional costs or a loss of profit. Other effects of injuries and illnesses include the negative influence on employee morale, corporate reputation and conflicts with contract partners. Based on this researchers asked the question: are mines with lower rates of injuries and illnesses more profitable than mines with a higher frequencies? One aspect of this research is the evaluation of the safety situation and the measurement of benefits of safety improvements in the German mining industry. In the following paper, this part of the research will be examined. The main aim is the evaluation of injury rates in different German mining sectors and regions in Germany. SELECTION OF GERMAN MINING OPERATIONS The research team decided to focus the study on the salt and potash and the aggregate and industrial minerals mining industries in Germany. These two mining industries are different in the number and size of operators, structure of the industry, pricing and markets. The selection of two different industries adds to the clarity of the evaluation. Salt and potash mining industry The German salt and potash industry is primarily located central Germany. All salt and potash mines in Germany are underground operations. In 2015, the German potash industry employed 8,100 employees and generated a total revenue of 2 billion Euros. German potash reserves include magnesium compounds like kieserite (MgSO4·H2O), in addition to sylvite (KCl) and carnallite (KMgCl3·6(H2O)). The German salt industry employed 2,300 people in 2015 and generated revenue of 800 million Euros (Krueger, 2015) There are seven mining companies with salt and potash operations: esco-european salt company GmbH & Co. KG, K + S Kali GmbH, Saline Luisenhall GmbH, GSES Glückauf Sondershausen Entwicklungs- und Sicherungs-gesellschaft GmbH, Südwestdeutsche Salzwerke AG, Wacker Chemie AG and Südsalz GmbH. In this way, esco – european salt company GmbH & Co. KG is an affiliated company. Esco was founded as a joint venture of K + S and Solvay in 2002, since 2004 K + S is the sole holder (esco - european salt company GmbH & Co. KG, 2016). Likewise, the Südwestdeutsche Salzwerke AG has a controlling interest in Südsalz GmbH (Südsalz GmbH, 2016). Aggregate and industrial minerals mining industry The aggregate mining industry in Germany is comprised of many small mining operations and relevant companies. According to the German Department of Economics (BMWi, 2015), the following industrial materials are classified as aggregates: fluorite, barite, kaolin, quartz and quartz sand, quartzite, silica, loamy and foundry sand, pegmatite sand, shale, clay, bentonite, schistose, limestone and dolomite, gypsum and anhydrite, basaltic lava and lava sand, gravel and split, pebble and silicic sand and peat."

Jan 1, 2017

By M. H. Pettibone

During the past decade, the size of grin- ding mills has steadily increased. Mills 11 m in diameter with 9 mW motors have been installed with even larger units on the drawing board. The rising costs of energy and labor have spurred interest in improving efficiency while reducing capital investment and operating labor. Autogenous and semiautogenous grinding have experienced renewed interest as efforts to reduce operating and capital costs have increased.

Jan 1, 1981

By Thomas W. Smelser

A full-scale geotechnical model of a 15-foot (4.6 m) wide coal mine entry in correlation with computer finite-element analysis (FEA) is being employed at the Bureau of Mines Spokane Research Center for basic research on roof-bolt support systems. Physical and computer modeling of various coal mine roof-bolt reinforcement systems will increase our basic knowledge of how roof supports function. This information, in correlation with computer FEA and underground verification tests, will provide a basis for establishing safer, more cost- effective roof control plans and help establish guidelines for employing fully grouted and conventional bolting systems. The basic rationale for the research, research approach, methods and equipment employed, results to date, and future research plans are described in this paper.

Jan 1, 1982