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The paper describes the progress made in the last decade with the introduction of comprehensive monitoring of the mine atmosphere into U.K. collieries. Brief descriptions are given of the various portable and fixed point instruments which have been developed for this purpose and the methods available for transmission of information to the surface are also discussed. The paper also outlines some of the research work being carried out both in the laboratory and underground on the development of alternative methods of fire detection. Some of the results from this work are illustrated and discussed.

Jan 1, 1981

By W. C. Hellyer

The papers in this section provide several examples of the application of Process Mineralogy to metallurgical problems. Any experienced metallurgist could cite numerous other examples when process mineralogy has, or could have, provided data of value in his understanding of metallurgical processes. The data developed by mineralogic techniques may supplement conventional chemical analyses, but cannot be replaced by assays. Mineralogic and chemical analyses each provide different types of information. In order for the process mineralogist to interpret his results in the most useful manner, it is desirable that he should have some knowledge of metallurgical processes. Conversely, the metallurgist should have some knowledge of mineralogic techniques to understand the scope and limitations. Mineralogic examinations are time-consuming and expensive. To ensure the effort is not wasted, and indeed does not generate misleading information, the utmost care must be taken at every stage of sampling and sample preparation. The mineralogist may examine microscopically or by x-ray diffraction a one-gram sample representing a flow of possibly thousands of tons per day through a concentrator. Conditions in a concentrator change continually in response to changes in feed rate, feed characteristics, grind, reagent additions, temperature, circulating loads, etc. Lengthy sampling periods are required to ensure the samples examined are representative of average conditions. The sampling program should be drawn up jointly by the metallurgist and mineralogist. Sampling points should be selected with a view to ease of sample cutting. The sampler should be instructed in the method of cutting the samples, the weight or volume of sample to be taken at each cut, the sampling frequency, and sampling period. The sampling period required depends on the scope of the investigation. For example, if a complete survey is to be made of all final and intermediate products of a flotation concentrator, samples should be cut at not more than two-hour intervals, twenty-four hours per day, for not less than one week. For a more limited investigation of one circuit or one section of a concentrator, 'the sampling frequency could be increased to every hour and the sampling period reduced to one or two days.

Jan 1, 1981

By Hans Werner, Gunnar Almgren

An overview of the first Swedish Research mine at Mt Luossavaara, Kiruna, Sweden, is given, including its background, objective , program and expected results. The Research mine involves the spending of approximately US$ 32 Million over a five year period of which 30% are financed by the Swedish Government and remaining 70% by income from ore sales. The main objective will be to develop an underground mining system based on rock mechanical pre-investigations and blast hole stoping using big holes. The research program will include the following main components:

Jan 1, 1981

By A. H. Leuschner, P. J. Kruger, J. Kruger

INTRODUCTION This paper deals with some practical aspects of the use and interpretation of dosimetric methods for assessing the exposure of workers to natural uranium. Consideration must be given not only to the scientific value of the method of dosimetry, but also to the practicality of the method in the particular working environment. It is generally accepted (IAEA, 1976) that uranium does not present a hazard during the mining and extraction processes up to the final concentration stage, that is precipitation as ADU or calcining to the oxide. Further processing (e.g. conversion to oxides, fluorides, etc.) is generally associated with the nuclear industry. It is customary for uranium processing facilities to be managed according to industrial norms rather than according to those applied for the purpose of radiation protection. This is mainly because of the large quantity of material to be processed and the fact that uranium is considered to be of a low radiotoxicity. Although ventilation is used to some extent, provision is not made for the same level of protection as would be required in a radiochemical facility. It is typical in such a plant to find that the process itself may be enclosed and ventilated, but the ventilation is inadequate to cope with an accidental release of material. The working environment is poorly ventilated, sometimes only by natural ventilation, and one frequently finds areas with high airborne dust levels, designated as mandatory respirator areas. Protection of personnel is dependent on personal protective equipment. Radiation protection is not of prime concern and personnel are not specifically trained in this subject. It is in this type of environment that acceptable monitoring procedures and personnel dosimetry must be established. The effectiveness and practical application of the dosimetry must also be judged against this working environment. DOSIMETRIC TECHNIQUES The methods available for assessing personnel exposure, whether it be in terms of chemical or radiological hazard, include urinalysis, faecal analysis and [in vivo] monitoring. Faecal analysis does not present itself easily as a method for routine use. Techniques for [in vivo] monitoring have been developed recently and as expensive instrumentation is required, it is not generally available. That leaves urinalysis as a dosimetric technique for routine use, and it is probably for this reason that urinalysis is still widely used. Guidelines for the interpretation of urinalysis results, as originally provided by Neuman (Neuman, 1950), are still used in practice, even though it has become clear that this method has severe limitations as regards the assessment of the dose as a result of the intake of class W or class Y compounds (Alexander, 1974). Typically a level of 300 µg [U/C] urine can serve as an indicator of an acute exposure (above which chemical damage to the kidneys may occur) and a level of 100 µg [U/C ] urine can serve as an indicator for an investigation. Such levels are determined and are used in conjunction with several factors, such as mode of intake (ingestion or inhalation), solubility of compound (D, W or Y), means of intake (acute or chronic), environmental monitoring results and frequency of urine sampling. Since the ICRP concept for internal radiation limitation changed from that of the critical organ, i.e. the single organ of greatest significance under the circumstances, to that of effective dose equivalent, i.e. account being taken of the total risk due to the exposure of all tissue, the maximum permissible organ burden (MPOB) was replaced as secondary dose limit by the annual limit on intake (ALI) (ICRP, 1977). The ALI values are calculated from the committed dose equivalents of the various organs, and are used to determine organ burdens, which are then used to interpret the dosimetric results. Using the ICRP model (ICRP, 1979), a comprehensive calculation was made by Johnson (Johnson, 1980), giving organ burdens and excretion data in terms of intake for acute and chronic exposures for different categories of uranium compounds. The question arises as to what extent the direct measurement of intake can be utilised as a method of dosimetry. This will require a method of personal intake measurement for each individual worker, with both ingestion and inhalation being taken into account. A measurement of

Jan 1, 1981

By James J. Wise

INTRODUCTION One basic design feature utilized in all caving and sublevel stoping techniques is the drawpoint. These draw- points may be located on sublevels when using sublevel caving methods, or may be located at the floor pillar when using block caving, sublevel stoping, or vertical crater retreat methods. How the drawpoint is designed and developed, how the ore is withdrawn from it, and how the ore is hauled to the shaft or portal encompasses the loading and hauling function. Historically, predominate loading and hauling equipment for caving and sublevel stoping has been scraper slushes, air powered overshot loaders, and rail mounted train haulage. All of this equipment has two common constraints. 1. The equipment locked into specific work sites and is not easily shifted to another work site. This constraint can often lead to low utilization and low productivity of the equipment. 2. The equipment is designed to work in the horizontal plane, which requires that the various horizontally-oriented working levels be connected by vertical raises. Vertical development by means of raises is not only increasingly expensive, but also is not well adapted to movement of large equipment into the s topes. In the last 20 years, two revolutionary labor saving concepts have become common in caving and sublevel stoping. 1. Long-hole drilling, which has mechanized the development of the drawpoint extraction structures as well as the actual stoping and undercutting. 2. Vertical access by means of trackless ramps between levels, and the consequent use of rubber-tired vehicles not only for loading and hauling ore, but also for the rapid movement of men, material, and equipment into the stopes. The introduction of trackless mining systems for loading and hauling has not been easy. Mine planners have had to re-orient their thinking to the larger operating space required by trackless equipment. Larger access drifts have necessitated reconsideration of mine layouts to insure proper ground support. Spiral ramp developments were often laid out on slopes steeper than the equipment could negotiate economically. Mine operators had to accept the added responsibility of roadway maintenance, water removal, increased ventilation, and more technical mechanical maintenance. As the mine operators enthusiastically embraced the superior productivity of trackless mining systems, they some- times disregarded opportunities to combine the older types of equipment with trackless vehicles to maximize productivity at lowest cost. In order to gain a proper perspective on this problem, it is necessary to review the various techniques of loading and hauling and to become more aware of the advantages or disadvantages that each system or combination contributes. LOADING Loading consists of two functions, (1) primary loading from a drawpoint and (2) secondary loading into long- haul system, a truck, train, or possibly a belt conveyor. Mine planners have four basic loading systems available to fit various operating conditions. These are, (1) gravity, (2) scrapers, (3) rail-mounted loaders, and (4) trackless loaders. Each system can produce optimum results under specific conditions. Gravity Loading Gravity loading is probably the oldest system in general use today.

Jan 1, 1981

By F. G. Hill

The paper reviews the restrictions imposed by the Department of Mines (now the Department of Mineral and Energy Affairs) on the surface use of ground that has been undermined at shallow depths (down to a depth of244m). The reasons for the restrictions are discussed, with special reference to the early records kept by the Department of Mines on subsidence and fracture of the surface. A discussion of the nature of the strata overlying the ore-body, and the effect of undermining, is followed by a detailed account of investigational work, particularly since 1970, on the stability of shallowly undermined ground. The significance of the data collected during the investigations is considered next, with special reference to the social and economic implications. These are so farreaching, that it is proposed that the already flexible approach of the Department of Mineral and Energy Affairs in considering what structures may be built on undermined ground should become even more flexible. To this end, the appointment of a Commission is proposed to collect as much information as possible on the stability of ground undermined at shallow depth, and to revise the current overrestrictive conditions or guide lines that are in use.

Jan 1, 1981

By J. W. M. Porritt, M. P. Brameld, R. H. McCorkell

"Soil-gas Rn was measured by two types of alpha-particle-track detectors, by emanometry and by counting alpha-activity on Rn-decay-product collectors. Soil samples were analyzed for V by fluorimetric and fission-track methods, their Rn-emanation by decay-product collectors and their total alpha activities with track detectors. The same uranium anomalies were revealed by each method. Fission-track analysis of leaves for V showed only random variations with sampling site, and the Rn emanation of trees and leaves removed from them was barely detectable . The agreement among the other methods is significant, total alpha and collector methods are simple, rapid and useful, and a combination of methods at a site would reveal disequilibrium in the U-decay series if present. Track-Rn measurements are highly reproducible and insensitive to apparatus design and their sensitivity is not enhanced by covering the detectors with thin foil or placing them in large containers.IntroductionIn the past two years , a number of methods of geochemical exploration for uranium have been tested by the authors over the known copper-uranium occurrence at South March, Ontario. This was done partly to compare methods and partly to develop and test new ones. The South march deposit has been described a number of times by others(1,2,3,4). The methods included in this study were the following.Emanometry, Radon in soil gas is measured by pumping the gas into the cell of a scintillation counter or emanometer(5,6). Alpha particles from radon (222Rn) and its decay products (218Po and 214Po) produce scintillations of light in the silver-activated zinc sunphide (ZnS(Ag) covering the walls of the cell. These are counted by a photomultiplier tube and scaler, the count ra sulphide (ZnS(Ag) covering the walls of the cell. These are counted by a photomultiplier tube and scaler, the count rate being proportional to the concentration of radon in the soil gas."

Jan 1, 1981

By Duk-Won Park, Syd S. Peng

For an adequate design of the shortwall face support, it is necessary to understand fully the support- roof interaction. A series of studies has been carried out at a shortwall panel to develop the methods of monitoring support resistance and determining load density of the chocks. Various aspects of applications, for improvement of chock design and understanding of roof conditions, are discussed.

Jan 1, 1981

By Vinton A. Garbesi

INTRODUCTION The placing of the monolithic concrete lining of the Bi-County water tunnel illustrates the state of the art in the materials, equipment, methods and productivity available to the industry for this type of construction. This paper describes the management and engineering rationale used by Clevecon, Inc., a subsidiary of S & M Constructors, Inc., Solon, Ohio, in developing the concrete mix designs, the design of the specialized equipment, and the methods used in the manufacture, transport, and placing of the lining. Also discussed are the changes to the reinforcing steel design instigated to facilitate its handling and placing, as well as to enhance the quality of the lining. The intent is to bring to the attention of designers the effects certain design aspects have on the construction of reinforced concrete tunnel linings, as well as indicate the areas where research and development effort should be expended to further reduce costs for this type of construction. GENERAL DESCRIPTION The Bi-County Water Tunnel West is a water transmission main owned by the Washington Suburban Sanitary Commission of Hyattsville, Maryland. The facility was designed by A. A. Mathews Division (formerly STRAAM Engineers, Inc.) CRS Group Engineers Inc., Rockville, Maryland. It is to be utilized as the central feeder of potable water for the northern suburbs of Washington, DC, extending some 4,597 meters from a riser shaft at its western terminus to the eastern interface, with a similar tunnel which extends eastward about 5,180 meters; the majority of its length being under Interstate Highway 1-495. The excavated and finished diameters are 3.8 and 3.05 meters respectively. The reinforced concrete

Jan 1, 1981

By Gealy W. Wallwork

INTRODUCTION The administrative processes of coal mines are becoming increasingly complex. As society evolves into a more complicated structure with greater emphasis on individuality, government regulations reach deeply into every activity in an effort to force individuals into a standardized mold. These contradictory pressures add an extra burden to the administration of a mining operation. Recent years have brought a substantial change in the skills needed by mine supervisors and managers. As a result, a better understanding of the administrative functions is necessary. The mine superintendent has the overall responsibility for the mine; for effective operation he must be sufficiently knowledgeable to oversee all the complex functions that make up the mine. This chapter does not cover all the administrative requirements because of the variation in mine operation and in company policies and organizational structure. It does attempt to identify the administrative functions that would be required at a large mine with a preparation plant. It is assumed that the mine operation is decentralized with very little duplication of functions at the organizational levels above the mine. Thus each function is assumed to be relatively complete at the mine and under the general supervision of the mine superintendent. EMPLOYMENT PROCEDURES Throughout the mining industry, in deep or surface mining, in union or nonunion companies, the success or failure of an organization is directly related to the caliber of employees who make up the organization. A company is nothing more than a group of people working together with

Jan 1, 1981

By C. A. Geffen-Fowler

This report, sponsored by the Bureau of Mines, presents the results of an examination of the safety of the Blind Shaft Borer (BSB) shaft sinking system and an alternative modified BSB design concept in comparison to conventional shaft sinking technology. Detailed study of the two systems was also performed to identify and recommend design changes for optimum safety conditions. A comparison of the BSB systems with conventional shaft sinking was made an the basis of relative risk levels. Risk incorporates both the frequency and the potential consequence of accidents. A safety evaluation of the component operations of the two BSB systems was performed using a Failure Modes and Effects Analysis (FMEA) methodology. The results of this analysis show generally that both BSB systems are safer than conventional shaft sinking. The potential risk of conventional shaft sinking operations could be reduced by over 30%, on the average, with the use of the original BSB system, and by an average of about 10% with the modified BSB. Design change recommendations to further improve the safety of these systems include a better fire suppression system, improved man haulage systems and more compact hydraulics. An operational safety manual was also developed for the modified BSB system.

Jan 1, 1981

By W. J. Kotzé

Die derde colloquium van die Spesialiste-afdeling van die SAIMM is op 19 November 1980by die Universiteit van Pretoria gehou en is deur sowat 40 mense bygewoon. Dr J. P. Hugo tree as Voorsitter op en heet al die aanwesiges welkom, en stel elke spreker om die beurt aan die vergadering voor.

Jan 1, 1981

By James C. Fowler

This report contains a description of the contract activities performed by ENSCO, Inc. under contract H0292025. The purpose of this project was to prove the feasibility of detecting hazards in a coal seam using a synthetic pulse radar. This work was conducted in three phases. The first was an analysis of the types of errors which might cause problems. The second was to build a breadboard radar and the third phase was to conduct a field test with the system. The work from each phase is discussed and the results of the field tests are presented. These results show propagation of the radar signal through 200 feet of coal along with reflections from 50 feet away. The final section contains recommendations for future development.

Jan 1, 1981

This paper forms part of a series of papers relating to the Melbourne Underground Rail Loop and presented to the Fourth Australian Tunnelling Conference in Melbourne, March 1981. The Design of Electrical and Mechanical Services in Museum Station and adjacent Running Tunnels and their relation to Rail.wruy Operation through the Loop are described. The descriptions, while specific to Muscrio Station, are generally representative of those being provided at Parliament and Flagstaff Stations. The Museum Station comprises some 6500 square metres of platform and track area, 5000 square metres of booking hall concourse and entrances and 1200 square metres of offices and plant rooms. The Mechanical and Ilectrical Services for this complex are .imilar in many aspects to those of a large !.gr.hrise city building, but in general the i::;ign is directed more strongly towards :.arety, durability and reliability, and subject to many restraints imposed by L'mitations of space and accessability.

Jan 1, 1981

The ability of activated charcoal or carbon to adsorb complex metal ions has been recognized for many years, but it wasn't until the late 1940s and early 1950s that attempts were made to employ carbon-In-Pulp or C. I. P. processing to the recovery of gold. Early plants using the process were those at the Golden Cycle in Cripple Creek, Colorado, the Getchell Mine near Golconda, Nevada, and at the Idria Mine in Honduras. Recovery of the carbon from the pulp was done by screening or flotation, and recovery of gold from the carbon was done by burning the carbon (a very difficult task) or by sending it to a smelter. Unfortunately at the time, the price of gold was still fixed at $3-5 per ounce and labor costs were rising to the point where these mines were no longer able to operate. Consequently, C. I. P. treatment was temporarily forgotten. In the early 1970s, however, Homestake Mining Company at Lead, South Dakota, were being forced by environmental regulations to discontinue the use of mercury for amalgamation in their 7,500 ton per day plant, and at the same time were encountering high labor costs in the slime circuit of the plant, where over 2,000 tons of slimes were filtered each day in Merrill plate and frame filter presses. Shortly before that, researchers of the United States Bureau of Mines had developed the caustic -cyanide method of stripping gold from activated carbon and an electrolytic cell (now known as the Zadra cell) to recover gold from the carbon strip liquor. Homestake and the United States Bureau of Mines then jointly operated a C. I. P. pilot plant at Lead. Results were immediately favorable and a 2,400 ton per day C. I. P. plant was then built to treat the slime fraction of the Homestake ore. (See Au and Ag Cyanidation Plant Practice, Volume I, SME of AIME, 1975. Later, Homestake built a second plant at Creede, Colorado, to treat the slime fraction of the tailings from a silver-lead flotation plant. Next was Duval Corporation's 3,000 ton per day C. I. P. plant at Battle Mountain, Nevada. Both of these latter plants are described in this volume. C. I. P. operations under construction at the time of this writing are as follows: Pinson Mining Co. , Nevada Gold Freeport Gold Company, Nevada Gold Compania Minera El Indio, Chile. Silver and Gold

Jan 1, 1981

By J. Wes Blakely

In the mid-1950s the importation of foreign oil began to encroach on traditional coal markets such as railroad steam engine fuel, home heating, electrical generating plants, and others. Many of the smaller coal companies with substantial coal reserves subsequently found that they could no longer continue to mine economically and merged in various ways with larger established coal mining concerns. As the seats of top management and authority were removed from the mines to large metro centers such as New York, Pittsburgh, and Chicago, the more personal relationship between mine workers and management that had existed prior to these mergers began to be eroded and replaced by 'remote control mine management. The disappearance of this face-to-face contact of upper management with mine employees tended to create barriers blocking simple effective communications between coal mine management and labor. In examining the human relations aspects of the coal mining industry, many elements, some concerned with work and others not, have depicted the industry as almost devoid of good applied human relations and communications practices, and, in truth, little has been done to alleviate this situation . In past years many coal producing companies, with the exception of one of the largest, failed to adequately define the term “communications” as it applied to their companies, whether internally or externally. Internally many still place heavy reliance on written communications such as company-wide newspapers to do the job of communicating with their employees which they feel ought to be done. One company puts an inordinate belief in its company "newspaper" as the primary instrument to stimulate its work force into increasing productivity. Primarily aimed at the workers, who greatly outnumber the salaried administrative people, this publication mainly documents the fortunes of individual mine workers who are felt to have achieved something with their lives, e.g., a mine worker who had managed to put four children through universities, the

Jan 1, 1981

By Richard C. Mayberry

Phosphate reserves have been and still are a controversial subject. Some published estimates are particularly conservative and have caused concern in government and political circles that southeastern phosphates are a dwindling resource. "Ores and ore bodies" are a function of economics that relate to a time/demand factor. The history of phosphates and other mineral commodities is one of mineral deposits (resources) ever becoming ore (reserves) via a long term logic based on price, supply, and demand factors operating through time and improved technology. Projections indicate that southeastern phosphates are sufficient for several centuries of operations at present production rates.

Jan 1, 1981

By Kenneth P. Katen

INTRODUCTION Though the use of continuous mining machines consolidated the operations of cutting, drilling, blasting, and loading in one machine that would theoretically provide uninterrupted production, it was soon realized that the face haulage and roof support operations remained as major impediments to continuous production. The ability to provide not only continuous cutting and loading, but also continuous haulage and roof support (see Fig. I), was the basis for the introduction of mechanized longwall systems in this country from Europe in 1951. The early systems employed friction props for roof support, but were to become obsolete shortly after introduction of the first hydraulically powered, self-advancing supports in 1960. Since then, use of the longwall technique has grown to the point where it is currently providing more than 5% of the annual output of underground coal mines in the United States. The shortwall system had its origin in Australia, but was first introduced into this country in 1962 following the development of powered roof supports. It, too, provides for continuous cutting, loading, and roof support (see Fig. 2), but has not experienced the widespread popularity of longwall due to its inherent inability to easily provide for continuous haulage. While there are in the neighborhood of 100 longwall systems currently in operation in this country, there are only a handful of short- wall operations providing production of slightly more than 907 184.7 t/a (1,000,000 stpy). Both of these systems provide uninterrupted roof support for face operations by means of hydraulically powered steel roof supports. In each case, the coal removal consists of open-end cuts made from the narrow end of a large rectangular pillar (panel) which has been blocked out by continuous miners developing entries around its perimeter. However, this is the extent of the similarities between the two systems. It is hoped

Jan 1, 1981

By Bruce Pinkston

This report presents a description of the Prototype Demonstration Vehicle and Safety Guidelines developed under U.S. Bureau of Mines Contract No. JO 366003, ?Improving Man Transit Safety. This vehicle was constructed to assess the feasibility of a set of equipment related guidelines which were drafted in Phase I of the same contract. State-of-the-Art improvements are embodied in such areas as collision survivability, occupant comfort, and multiple mode (on and off rail) operation. The electric battery powered vehicle carries a twelve man section crew at speeds up to 12 mph. The description of the demonstration vehicle Is presented In Volume I. Safety Guidelines are presented in Volume II.

Jan 1, 1981

Drill and blast excavation in underground mining and. civil engineering projects has grad- ually given ground to mechanical boring of tun- nels, shafts and raises during the past twenty years. The use of.boring equipment must today be considered significant and wide spread al- though comprising only a very small percent of total underground excavation. The encroachment of mechanical boring into the domain of blast- ing has been by slow incremental advances. There have been few, if any major breakthroughs in this development, and none can be foreseen in the next decade. After 1990 it is possible that scientific. development will provide some form of breakthrough in rock breaking, but this is so uncertain that it should have little relevance to planners in the 1980's. A more near term view of the future, con- centrating on the next five to ten years, has lead to the conclusion that significant im- provements will be seen in tunnel borers for poor ground conditions. A universal machine will be developed that converts from a dry hard rock machine to a closed slurry type machine for passing through fault zones with unstable crushed rock and water. Two other machines have been described as alternate designs for tunnelling in squeez- ing ground conditions.

Jan 1, 1981