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By C. C. Nolan

As the size of the mills get larger and the liners get heavier, a better means had to be found to handle liner replacement. McLellan Industries is famous for their innovative ideas and was called upon by an engineering company to develop a mill liner crane. The first crane was developed for Similkameen about 1969 to serve a 32' 0 x 14' Long SAG Mill. The next was Island Copper in Port Hardy, B.c., the same size as Similkameen in 1970. At that time, we took existing hydraulic cranes and modified them to meet the mill configuration. In 1973, we developed a completely new approach for the Southern Peru copper mine at Tacna, Peru for a Ball Mill, size 16'-6" 0 X 19' Long. Each installation required a design study to meet the change in mill size, trunnion size, elevation of floor to feed trunnion, area at the feed or discharge end of the mill. We have supplied self-propelled units as well as lift in. When there is no room at the feed end and if the mill has a trunnion overflow discharge, we have the mill supplier provide a structural frame to span the sump and move the mill liner handier into position with the use of the overhead crane or a mobile crane.

Jan 1, 1999

By Art Hamid, Manfred Wong, Carlos Jaramillo, Greg Raines, John Caulfield

"The Central Bayside System Improvement Project (CBSIP) is a critical element of the Sewer System Im-provement Program (SSIP), a 20-year, $6.9-billion investment by the San Francisco Public Utilities Commis-sion (SFPUC) to upgrade San Francisco’s 100+ years old seismically vulnerable combined sewer system. The CBSIP’s centerpiece, a proposed 10,000-foot-long (3,048-meter-long) Channel Tunnel, will provide reliable and redundant gravity conveyance and storage of combined wastewater flows from the northern and central parts of San Francisco to the Southeast Water Pollution Control Plant (SEP) while ensuring compliance with regulatory requirements for combined sewer discharges to the Bay. A tunnel with a diameter of 23 to 30 feet (7 to 9 meter) is being planned using pressurized-face tunnel boring machine technology. Project challenges include tunneling through Franciscan Bedrock, mixed ground conditions in close proximity to the Bay, connector tunnels and shafts, construction in congested urban environment, and challenging real estate issues for shaft access. BACKGROUND AND NEED FOR TUNNEL The City of San Francisco is one of the most beautiful cities in the world. About 850,000 people live in the city and many more come to work, for tourism, and for attending conferences. The SFPUC is a department of the City and County of San Francisco that provides energy, drinking water and wastewater services to San Francisco, wholesale water to three Bay Area counties, and green hydro-electrical and solar power to San Francisco municipal departments. The SFPUC wastewater system includes tunnels, large storage/transport boxes, 1000 miles of collection sewers, 28 pump stations, and three wastewater treatment plants. San Francisco’s combined sewer system collects both wastewater and stormwater in the same sewers, which is then pumped, treated to stringent state standards and discharged into the San Francisco Bay and Pacific Ocean. After decades of service, much of the sewer system is nearing end of its working life. During the 1989 Loma Prieta earthquake, damage to SFPUC water and wastewater infrastructure was extensive. The 11,200-foot-long (3,400-meter-long), 66-inch-diameter (1,676-mm-diameter) Channel Force Main, built in 1976, and a critical component of the SF wastewater system was also damaged. This force main carries 70 percent of the bayside dry weather sewage flow from the northern and central part of the city to the SEP. The force main is at the end of its life and was not constructed to the current seismic code; in addition it has no redundancy. Figure 1 shows the project background and the force main that will be provided redundancy by the new gravity tunnel."

Jan 1, 2016

By F. Calizaya, S. Bhattacharyya

"INTRODUCTION Mechanized underground mines often suffer from noise overexposure. Noise levels are usually above the Permissible Exposure Limit (PEL) where underground fans are used. Sound levels in active workings can reach 121 dB(A), especially when fans are not equipped with silencers. Use of silencers seldom ensure PEL for various reasons. Overexposure of noise induces permanent hearing loss among mine workers. Recent field studies by a NIOSH-funded research project at six coal and non-coal mines revalidated the findings. The University of Utah has undertaken laboratory studies to reduce fan noise at the source. A new silencer prototype with varying noise dampening material has been designed and tested. The silencer and an associated extension which can be repacked with different dampening materials were used in various configurations. Attempts were made to simulate field conditions where installations are quick and not perfect. The test results are presented here. NOISE IN UNDERGROUND MINES Noise induced hearing loss (NIHL) is a chronic problem in the mining industry. In spite of regulations being in place and elaborate hearing protection programs under way, hearing loss is prevalent among the mine workers (Bise, 2001). All production and support machinery in mining generate loud noise often beyond the approved exposure level. Researchers in the U.S. have identified auxiliary fans as one of the major sources of noise that can create noise exposure levels up to 121 dB(A), which is one of the highest in the mining operation (Bauer, 2006). Studies have demonstrated substantial reduction of noise level by using silencers. Adequate fan selection and proper utilization of silencers in auxiliary fans have great potential of abating the problem. In hard rock mines, auxiliary fans are used in blower configuration to ventilate development headings and large production stopes, and also to ventilate underground shops, crushers, conveyor transfer points, etc. Typical duct diameters in hard rock mines vary from 0.91 m to 1.21 m. Silencers are often omitted for cost reduction. In coal mines auxiliary fans are used in exhaust configuration with rigid ducts 0.61- 0.76 m in diameter (Hagood, 1982 and Moreby, 2009) to ventilate working faces in gate-roads and main entry developments. Sometimes, stone dusters are added at the discharge end to dust the roof, ribs and floor. AUXILIARY FANS AND SILENCERS Auxiliary fans are relatively smaller in size than the main fans and often have high rotational speeds (1800 -3000 rpm). Fans are selected based on pressure-quantity requirements and space restrictions only. Noise emissions are rarely considered during the selection stage. Installation of fans, ducts and other accessories is mainly based on best practices, which often do not include noise control. As a result, the operation of an auxiliary or local ventilation system normally produces excessive noise."

Jan 1, 2018

By A. Benchekroun

The phosphate mining industry is confronted everywhere in the world with financial difficulties and low prices which prohibit further investments and development of new mines even in regions with a comparative cost advantage (North America/ North Africa/ and Middle East). But old mines are being progressively exhausted/ and if no replacement mines come on stream in the near future/ we may soon find ourselves (around the year 2000) with a global annual production capacity of 160 million tonnes of marketable phosphate rock instead of the capacity of 200 million tonnes existing today. Unless prices improve/ phosphate rock/ a non-renewable resource and a vital commodity to world agriculture/ may turn to be in short supply to world fertilizer industry. Whatever the extent of recovery of fertilizer demand/ the expected decline of the production capacity during the 1990 I s is bound to cause the disappearance by the year 2000 of the important surplus characterizing today the supply/demand balance.

Jan 1, 1995

By S. D. Van Nort

Editor’s note: This is the first of two MINING ENGINEERING articles about the Grasberg deposit. The second, focusing on open pit mine development, will appear in the April issue of the magazine. The Grasberg porphyry copper-gold deposit of Freeport Indonesia Inc. lies within the Ertsberg Mineral District in central Irian Jaya, Indonesia. The Grasberg deposit was discovered during a drilling campaign initiated in the mid-1980s. Production at the open pit de- posit commenced in December 1989. The Grasberg copper-gold ore body is contained within a young igneous complex of dioritic composition that intrudes limestones of the Tertiary New Guinea Group. Alteration is typical of porphyry copper deposits worldwide except that higher grade primary chalcopyrite with significant gold values is associated with a centrally located zone of strong quartz stockwork. Irian Jaya comprises the western half of the island of New Guinea. The Ertsberg District lies 70 km (43 miles) inland from the Arafura Sea at an altitudeof3500 to45OOm (11,480to 14,764 ft). It straddles the Papuan fold belt. This belt forms the east-west trending chain of mountains that extend the entire length of New Guinea and is the site of numerous mineral districts.

Jan 1, 1991

By Konstantinos Theodoridis, Michael Galetakis, Olga Kouridou

Recent advances in Artificial Neural Networks (ANN) and Adaptive Neuro-Fuzzy Inference Systems (ANFIS) have provided a new approach to the estimation of related quality characteristics, such as heating value, ash content and moisture of coals used for power generation. The basic strategy for developing ANN and ANFIS models for the prediction of missing quality values, is to train the models using an existing quality data set and an appropriate learning method. Statistical analysis results of the estimated values, showed that ANN and ANFIS are not only more accurate than the widely used regression models, but also tends to reproduce the variability of the initial data, while regression models generate a smooth representation of reality.

Jan 1, 2002

By S. Kmet, A. Nguyen-Van, H. J. Schulze

The P/B collision and attachment interactions in fine particle flotation have been quantitatively analyzed. New models for attachment probability and kinetics of ‘true flotation’ have been developed. The results are given for both a single bubble and a bubble swarm. The mechanism of the attachment event is also examined. It is shown that (i) impact collision mechanism and rolling mechanism can be ignored in actual fine particle flotation and sliding mechanism is of importance for attachment of particle onto the bubble surface (ii) the attachment probability of fine particles is independent of bubble size and determined by the kinetic measure induction time of hydrophobicity. The theoretical predictions are also compared with the experimental data.

Jan 1, 1995

By Shuang Shuang Huang, John Fillos

Ozonation was evaluated as an alternative treatment process for leachates of municipal landfills. The study was carried out on leachate from the Fresh Kills Landfill, New York City. The leachate has strong tea color and BOD5 ranging between 90 mg/L and 130 mg/L. The average COD, TOC and NH3-N concentrations were 1800 mg/L , 550 mg/L, and 665 mg/L, respectively. The kinetics of the process were studied in a sparged batch reactor by developing concentration- time profiles for residual color and TOC. Continuous flow experiments were then carried out at two selected contact times. The process was found to be effective in the treatment of leachates for color and TOC removal.

Jan 1, 1992

By R. M. Clowes

LITHOPROBE is a collaborative, multidisciplinary research project that is providing new insights into the tectonic evolution of the North American continent through its work within 10 study areas across Canada. For the mining industry, such results provide a well-constrained regional framework and better understanding of the tectonic processes that lead to the development of ore deposits. In mining camps, seismic-reflection methods have proven effective in imaging shallow to moderately dipping lithologic contacts as well as structural features and, in some cases, have been used for the direct detection of orebodies. Here, short case histories are provided for the Abitibi greenstone belt (VMS deposits) in Quebec and the Thompson nickel belt in Manitoba.

Jan 1, 2002

By Jorgen Elbrond, Xiaoli Tang

In this paper we apply continuous-time option pricing theory (Dixit 8 Pindyck 1994) to show how to obtain an optimal investment rule for a mining project which requires sequential in- vestments. The application per se is to some extent very simple. The main purpose of the paper, however, is to draw the attention of mining people to how the option pricing theory may be used to capital investment decisions. This topic in economics is quite new but is attracting a lot of attention.

Jan 1, 1996

By J. D. Pfarr

The Homestake Mine, located in Lead, SD, has been in business for 113 years. Until 10 years ago, conventional mining methods were used to extract ore. Due to complexities in the ore bodies and increasing costs, new technology was introduced to the mine. An integral part of this technology was mechanized cut-and-fill mining. This mining method currently produces about 50% of the annual production and has proven to he safe and economical. As a result, the Homestake Mine remains competitive in today's market.

Jan 1, 1992

By R. W. Utley, J. Carr

The tremendous growth in grinding mill size and horsepower during the 70s demanded advancements in gear cutting technology and equipment for the 80s. A new standard in gear cutting machines is now used to generate-cut large open gear sets to over 12.2 m (40 ft) in diameter at an AGMA quality level much higher than the accepted levels a short five years ago. The precision of the resulting gear set assures maximum tooth contact with the resultant longer gear set life.

Jan 1, 1987

By Paul Higley

Specialty Devices, Inc. and the CMRET/NIUST, University of Mississippi, have collaborated in the design and development of a new class of Robotic Underwater Vehicle (ROV) focusing on efficient, low cost, deepwater operations. The need for such a vehicle was driven by special requirements encountered in the establishment of the Gulf of Mexico Gas Hydrates Research Observatory at a depth of 850m in Mississippi Canyon Block 118 on a restricted budget. Requirements included deployment and recovery of tools and sensors and the connection of underwater-mateable electric and fiber optic connectors at depth. The standard complement of equipment required included; high-resolution video with lighting, scanning sonar, robotic arm, precision positionin and thrusters for limited transit and maneuvering. Conventional deep water ROVs are lowered in a large cage with a buoyant tether between the cage and the ROV. The tether is wound on a winch in the cage deployed as the ROV swims out from the cage. This cage is lowered on a large diameter umbilical cable with strength elements and communications elements and conductors for electric power. With increasing water depth the umbilical cable must become ever larger to accommodate increased power transmission loads and strength demands, with corresponding increase in deck handling equipment size and in turn, vessel size and overall cost. The surface ship must include a dynamic positioning (DP) system to control ship propulsion to maintain the position of the ROV cage at a position relative to the sea floor. DP ships with this capability and the ability to carry the large umbilical cable and winch are expensive.

Jan 1, 2008

By C. Pomeroy, J. Weyer, J. Brune

"Mining began in the Erzgebirge (“ore mountains”) region of Saxony, Germany more than 800 years ago, and extensive underground workings cut through the entire area. Some of these old workings are still used today: not for production, but for offering an underground venue for research, tourism and university teaching. One example is the Reiche Zeche mine at the Technische Universität Bergakadamie Freiberg which hosts one of the oldest mining engineering programs in the world. It is imperative to keep all active mine workings well ventilated to make the mine safe for students, visitors and researchers. Since the mine workings at Reiche Zeche are so vast, extensive and, to a large extent unexplored and unmapped, it has been difficult to provide a complete, functioning and adequate mine ventilation model for this mine that accounts for all known and unknown leakage air flows. Researchers at the Colorado School of Mines have cooperation with their colleagues at Freiberg to establish a mine ventilation network model based on a limited number of air readings in known and accessible drifts. In order to balance the measured air quantities, leakage flows were quantified and mapped by comparing input and output flows of mapped drifts, and modelled using Ventsim Visual, a powerful visualization software package. The resulting mine ventilation model is used to locate and quantify the leakage air flows and to examine how much air is lost in each area. With this model, ventilation changes and improvements underground can be documented reflected in the model. This enables the Bergakadamie Freiberg to project air changes required for scientific experiments and to set up mine ventilation in specific areas and for specific needs. The model also enables better ventilation control and monitoring than before. Finally, the model can be used to predict ventilation changes and escape way contamination in case of a fire, ground fall or inundation in the mine. The latter becomes important as the lower mine workings are often flooded during spring runoff, which has created uncertainty about mine ventilation in the past. HISTORICAL BACKGROUND The discovery of silver, lead, zinc, tin and other valuable metal ores in the Erzgebirge region of Saxony, Germany began in the12th century and started a mining boom than lasted for centuries. Surface mines quickly developed underground to access the higher grade veins. Explored by the early geologists and driven by the ingenuity of the miners, the underground works expanded vastly throughout Freiberg and the surrounding region. Development followed the highest grade veins, and engineers developed solutions to drain water and provide limited ventilation to the underground workings. Still, engineered and planned ventilation was usually not a priority in the development of a new drift, which today makes ventilation modeling a significant challenge."

Jan 1, 2015

By John H. Archibald, Arthur L. Miller, George A. Savanick

As part of its continuing research on selective mining, the Bureau of Mines has made progress toward developing a tool capable of remotely extracting hard minerals through a borehole. As the successor to the successful borehole miner, which extracted soft materials through a straight borehole, this new device has several innovative features: 1) it can propel itself in and out of an 8-inch borehole; 2) it can cut hard rock with an abrasive jet and transport the cuttings to the surface; and 3) it can negotiate deviated boreholes--the feature that enables it to follow a vein and extract only the values. This paper describes the development and feature testing of the reamer/miner.

Jan 1, 1991

By Donald D. Haas

Contract mining has a definite place in the mining industry, both in the United States and around the world. A mine owner should evaluate the utilization of contract mining in the devel­opment and production of mining properties. This evaluation of contract mining should be performed at various times in the life of a mining prope1iy from the development and initial operation of a new mining project, periodically throughout the mine's life, and at mine closure. Many factors must be considered in ana­lyzing and evaluating the potential of contract mining and those factors are both quantitative and qualitative. Quantitative factors are those factors for which costs or measures can be determined or estimated objectively; and qualitative factors are those factors for which costs or measures must be determined subjectively and do not lend themselves to objective determination or estimation. Some of the qualitative aspects may provide only yes, maybe, or no answers while others will provide a tendency or partiality toward one answer or the other without a quantified cost. The major quantitative aspects include operating and capital costs, monitoring costs, capital preservation, acquisition and disposal of new and used equipment, direct payroll and administrative costs, recruiting and training costs, and employment and termi­nation of staff and hourly personnel. The major qualitative areas include corporate philosophy, risks associated with capital and operating costs, financing the project, operating control, operat­ing flexibility, recruiting and training of personnel, employment and termination, administrative concerns, and owner/contractor relationship.

Jan 1, 1998

By E. Topuz, Xing Wu

INTRODUCTION The air flow in the mine ventilation network can be categorized in three ways: natural splitting, controlled splitting, and semi-controlled splitting. In natural splitting, the air flow in branches of a ventilation network apportions itself according to the aerodynamic resistance of the branches. In controlled splitting, a prescribed quantity of air is circulated through each branch. In semi-controlled splitting, flow in some branches is fixed to a desired quantity while in other branches it is split naturally. In practice, the mine ventilation networks present the latter two situations. Usually, the resistance of each branch in the network is known and the quantity of air in the working place is predetermined by safety considerations. If the number of branches whose airflow quantities are known is equal to or larger than the number of the fundamental meshes in the network, then the network becomes a controlled splitting network (Wang, 1982 a). Otherwise, it is a semi-controlled splitting network. If no booster fans are used in the network, the problem can be solved as either controlled or semi-controlled splitting networks in order to determine the main fan pressure and regulator size and location. All techniques are based on Kirchoff's flow and energy conservation laws and Atkinson's Equation. Booster fans can be used in controlled and semi-controlled splitting networks. It has been proven both theoretically and practically that using booster fans in these ventilation systems can improve flow distribution and reduce consumption of power (McPherson et al., 1985). The current techniques used in determination of booster fan location and size include simulation, linear programming, CPM and cutset operation, out-of-kilter, and critical-path crashing. These techniques can be classified into two groups. The first group, including linear programming, CPM and cutset operation, out-of-kilter, and critical-path crashing techniques, deals with controlled flow networks. The second, simulation, can be applied to the handling of semi-controlled flow networks. Mathematically, the problem of controlled splitting networks can be solved more easily than that of semi-controlled splitting networks. This is because the controlled flow network can be formulated as a linear programming problem, for the solution of which there are several sophisticated algorithms. Moreover, the semi-controlled flow network is usually modeled through nonlinear programming, for which there are no universally applicable solutions. The procedure described by Wu and Topuz, 1986, can be used to convert a semi-controlled network to a controlled flow network, and the problem can then be easily solved by the techniques used for solution of a controlled flow network problem. In practice, a mine ventilation network may change from controlled splitting to semicontrolled splitting with advancement of mining. This dynamic nature of mine ventilation makes the problem more complicated and necessitates development of new solution procedures which will consider the overall economics of the system. CONTROLLED SPLITTING NETWORK The problem in controlled splitting networks with booster fans is to determine the operational characteristic of the main fans, and the location and size of booster fans and regulators. The objective is to satisfy the air flow rate requirement for each branch while minimizing consumption of energy. The techniques used for the controlled splitting network problem include linear programming, CPM and cutset operation, out-of-kilter, and critical-path crashing. The objective function and constraints can be expressed as follows (Wang and Pana, 1971): [ ]

Jan 1, 1989

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

INTRODUCTION The majority of ground water flow models have been developed for large computer systems. Most of these operate under a batch mode of operation, that is, the data are input with a deck of punched cards. The advent of micro- and minicomputers over the last few years opens the possibility of adapting many of these large flow programs to the smaller computers. In general, this adaptation will require more computer time to run the program, but in many cases if the small computer is in-house, the overall cost may be less than that required for a large computer. There are also a number of peripheral devices that can be used to make the data input much easier. As an example, the use of a digitizer with a finite element or finite difference mesh reduces the data input time considerably; the use of a graphics terminal for display of the mesh immediately after it is developed shows immediately whether there are errors in the location of node points. DEVELOPMENT OF AN INTERACTIVE SYSTEM The finite element program, UNSAT2, has been used over the past several years by the authors for several ground water flow problems (Bloomsburg, 1977; Bloomsburg and Wells, 1978; Zahl and Bloomsburg, 1980). In the past these programs have been run on an IBM 370/ 145 computer under the batch mode of operation. One difficulty that has been encountered has been in determining the length of time step that must be specified for operation of the program. The problem is that if the time steps are too large, the program becomes un- stable and operation ceases. If this happens in the middle of the problem, the only alternative is to reduce the length of time step and repeat the entire run. This problem has been alleviated in other pro- grams by using a subroutine that determines the time step automatically. If the solution becomes unstable, the time step is reduced automatically and that portion of the solution is repeated. With an interactive system this can be done by storing the output pressures and restarting the program with the new output pressures. Under the batch mode of operation, there is an option in UNSAT2 that allows restarting of the program from the last point of solution, but this must be specified when originally starting the program. The interactive computer system that we use currently consists of a PDP 1 1 /23 with hard disk drive, CRT terminal, plotter, graphics terminal, digitizer, and printer. The computer has 256 K bytes of core storage and the hard disk drive will accept a 5.2 M byte disk. To run a large program on a computer such as this, some overlaying must occur; that is, subroutines are stored on disk and put into core storage only when they are actually needed for running the program. UNSAT2 required very few changes to run on this computer but some changes were necessary to take advantage of the interactive capabilities of the system. One of these changes consists of the development of a program called DBUILD to build the data file for running the program. This program calls for each piece of data by prompt statement and gives instructions for using the digitizer. The data are then entered in completely unformated form. The node points must be entered in order and the coordinates are determined automatically by the digitizer. The pressure readings or initial conditions on each node point are entered through the terminal. All element information also is entered through the terminal. After DBUILD is run the mesh may be displayed immediately on the graphics scope whereupon any error in node point

Jan 1, 1986

By W. M. Kidd

INTRODUCTION Uranium mine inspection in Canada forms one element of the enforcement of the Atomic Energy Control Act; it is under this Act that all Canadian uranium mines and mills are licensed to operate. Inspection duties are carried out by a small core staff of federal government inspectors (working for the Atomic Energy Control Board (AECB)) largely supplemented by provincial mine inspectors working on behalf of the AECB. Unlike most resource extraction in Canada, uranium mining is under federal jurisdiction and consequently it was the AECB who decided in 1975 that changes in the Canadian uranium mining industry, particularly its expansion and the expanding role of the mine inspector in the limiting of exposures, warranted the offering of a special radiation protection training course. The Uranium Mine Inspector Training Course (UMITC) was first conducted in 1976 at the Elliot Lake Centre in Elliot Lake, Ontario. Subscription for the course was not limited to mine inspectors to enable union stewards, management personnel and provincial/federal labour inspectors to attend. This paper will present an outline of the course content, the format of its presentation and non-curriculum aspects of running a course of this type in uranium-producing community. The core lecturers for UMITC are drawn from the Radiation Protection and Uranium Mine Divisions of the AECB. In addition, guest lecturers are invited from universities and medical research centres together with industry professionals and government researchers. In all some twenty-four plus presentations are made over the first five days of lectures. The program topic areas, hazards, controls, measurements, record-keeping and health effects are preceded by an intensive half-day session on radiation fundamentals. TOPICS Hazards [Dust] A review of the dynamics of airborne particles including the effects of particle size, gravity and wake-turbulence on the behaviour of dust clouds. Associated topics are migrational aspects of dust particles and specific dust-generating mine operations. [Radiation] Canadian uranium mines are increasingly diverse in nature ranging from large scale low-grade underground operations in Elliot Lake to smaller high-grade open pits in Saskatchewan. Papers are presented on assessments of internal and external exposure, the metabolic pathways of ingested or inhaled radiation and the specifics of mine and mill hazards. Radiation hazards are further broken down into gamma surveys of uranium mines, radon daughter concentrations and problem areas. Controls The relationship between mining methods and the operating environment is critically important to ensuring safe working conditions. This refers to both the selection of machinery/devices, etc., and to engineering controls which are instituted to remedy problems created by new technology. UMITC examines a number of possible mining techniques, their criteria for selection and impact on the working environment. Control measures, ventilation practices and design, the need for continuous water misting and special open-pit precautions are presented. These lectures frequently conclude with suggestions for better operating guidelines for mine ventilation systems and the need for greater co-operation between the ventilation department and the underground crews. Measurements Uranium mining regulations stress the need for a high standard of exposure monitoring, statistical planning and record-keeping. [Statistics] Although many course participants are well versed in statistics, certain fundamentals are repeated and include, the concepts of mean, variance, standard deviation and standard deviation of the mean. Confidence levels, decision-making based on sample statistics and statistical records are also discussed. [Dust Measurement] Dust measurement is particularly critical in the mines where the high silica content of the ore body, such as those at Elliot Lake, results in the continuous generation of dust. Sampling practices, filtration, impaction, thermal impaction and electrostatic precipitation are explained together with the methods of counting samples to determine free silica. Konimetric and gravimetric techniques for dust sampling are compared and contrasted. [Radiation Measurements] Both collective and personal dosimetry systems are used in the Canadian uranium mining industry and lectures are presented on each. Techniques and possible sources of error are discussed for a variety of radon and radon daughter measurement methods - Lucas method, Tsivoglou and modified Tsivoglou, Kusnetz, Rolle. Instant working level meters and personal alpha dosimeters are explained in terms of calibration, maintenance, readout and estimation of accuracy. A lecture outlining dose estimation by means of bio-assay, whole-body counting and the use of TLD's concludes the topic. Record-Keeping An overview of the problems of changing limits,

Jan 1, 1981

By D. Zaharaki

In the present experimental study the geochemical stability of inorganic polymers was studied by immersing them in various solutions (distilled water, seawater and 0.5N HCl) for a period of 7 months. Inorganic polymers were synthesised by mixing ferronickel slag with kaolinite, potassium hydroxide and sodium silicate solution. The cement like paste was heated at 80 °C for 48 hours and left for curing at room temperature. Their structural integrity was assessed by compressive strength testing after subjection to freeze-thaw cycles as well as high temperature heating. XRD studies were carried out in order to identify new formed phases and provide useful information regarding the progress of the mechanisms involved.

Jan 1, 2008