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By Lennart Malmqvist

Decision-making in exploration deals with experience, knowledge, and sometimes faith, but very often financing and profit, mineral resource aspects, employment, and general political ambitions are parts of the scene. At one end of this spectrum, there is the prospector and his decision on the actual project. The exploration business now expands from its pioneering phase for the benefit of a single company to a wider spectrum which includes the benefit of the large mining consortium and a national development program. Its objectives are also to maintain employment and to favor long-term stability in a mining district or a mining company. The prospector then has new aspects and questions to consider such as, what to do in mining districts where there is a shortage of ore resources but there are still useful investments in mines, processing plants, etc. To analyze the exploration process, therefore, seems to be of great importance in a time of rapidly changing conditions. As in other areas of complex decision-making, for example, in the fields of investments, of production, and of the armed forces, computers most certainly have an important role to play in future exploration decision-making systems. However, we must first analyze our own business as closely as possible to find out what kind of information we need, i.e., why we recommend an exploration program as a good or a poor one. An important part of the debate about exploration is the case study. Case studies on exploration are few and most of those written are only about successful exploration programs. Where are the case studies of the failures and the not so successful programs? Every prospector knows that the majority of exploration projects fail. Consequently, the most important experience seems to be hidden in the failures.

Jan 1, 1979

By Patricia O. Milley

Two years ago, AlliedSignal embarked on a journey to improve QUALITY. However, the focus of this endeavor was on the CUSTOMER and not the traditional product focus. It wasn't that a focus to improve product quality wasn't fruitful in the past. We've practiced it in the chemical industry for many years with significant results. But our industry today is in a survival mode and yesterday's way of doing business is simply not good enough. In the mining industry, we have to make lug strides in how we do business or face losing our customer base. As you are well aware, other parts of the world are importing our technology at a rapid rate. We must work smarter to stay ahead of our customers ever more demanding need for higher quality at lower prices. With this as a driver, throughout the Corporation we reviewed in depth how we support our customers to keep them competitive and sought to eliminate work which did not help them reach this goal. Our first year of emphasis was on tools: how to hold meetings, gather data, and how to make decisions. This sounds very basic, I know, but you can't begin to imagine how productive meetings can become when you start with an agenda and prework delivered days in advance, and agree at the start of the meeting what should get accomplished. In the second year, we applied these tools to our work processes. We mapped how we do our work, scrutinized each step for value to the customer, and then set to work on how we could do things better. The areas we concentrated on were customer linked commercialization of new products, manufacturing and materials management. Our discussion today will focus on the commercialization of new products.

Jan 1, 1994

By Richard D. Doepker, Cathy A. Summers

Part 1: Physical Characteristics The physical and mineralogical characteristics of samples from five sources in the Western United States were determined using size analyses, microscopic studies, and point counts. These results were combined with leachability assays and the chemistry of leachates obtained during slurry tests to predict sample dissolution characteristics during column leaching tests. Part 2: Dissolution Characteristics Two columns of each sample were leached over a period of 3 years with synthetic rain. Residence times were between 2 and 11 weeks. The samples were subjected to daily and seasonal temperature fluctuations and wet-dry and freeze-thaw cycles. During the latter part of this study, a biocide leachant (sodium benzoate) was substituted for synthetic rain to assess the degree of dissolution caused by biological oxidation. It was found that the presence or absence of barite or carbonate minerals can be used to predict the leaching behavior of the column material.

Jan 1, 1995

By T. D. MacQueen

Thank you Mr. Stevens. It's a pleasure for me to be speaking to this meeting of the Society of Mining Engineers of AIME this afternoon, and the Gypsum, Association is grateful for the invitation. A brief word about who we are: the Gypsum Association is the trade association for the gypsum industry - the manufacturers of gypsum board and lath a-d plaster. We have a membership of eight companies. These eight companies produce about 90% of the gypsum products manufactured in the United States ... closer to 94% actually. Our headquarters is in Evanston, Illinois. We have an east coast office in Washington, D.C. where the eastern manager handles technical and building code matters and maintains liaison between all of the government agencies and departments and our industry. We also have a west coast office in Los Angeles where our west coast representatives is heavily involved with the Uniform Building Code and ICBO. And then in the Evanston office our manager of technical and building code services, Herb Carlsen, bites his nails and loses his hair over these problems and various other projects that come in, such as conversion to metric and various other things. We also have a research associate at the National Bureau of Standards in Washington who is currently concentrating his efforts on the combustibility of building materials. His studies involve current testing methods, definitions, data analysis, and proposed new testing methods,.' It is anticipated that this program will lead to a better understanding of non-combustibility of building materials and systems. I mentioned that our members represent over 90% of gypsum products,' manufactured in the United States; it might be well to point out a couple of statistics about what that really means. According to the Bureau of Mines,

Jan 1, 1977

By Eugene L. Foster

The engineering profession has traditionally devoted its efforts to understanding and modifying the Earth's environment in order to adapt it to man's needs. In appraising our overall performance, I would have to say it has been a mixed bag. In many areas, notably communications taken in the broadest sense, and development of creature comforts, we have done a good job. In others, we have failed, particularly in our assessment of the effect of our work on the environment. Our failures have been due in part to a lack of understanding or foresight, and in part to a disproportionate emphasis on lowest first cost. Now, with an increasingly large number of people living in a finite environment, there is an urgent need for reassessment. It is no longer possible to pursue a single objective without regard to its side effects. Our projects are too large, and there are too many of them. Environmental impacts must be taken into account in all important engineering decisions of the future. There are forces at work which will help to bring this about. Thinking people everywhere have realized that adverse alteration of our environment eventually affects every one of us. The majority of our citizens, who now live in cities, are beginning to appreciate the advantages of a good natural environment in a way which others who have been closer to the soil have appreciated for years. Our people have flocked to the cities because they wanted to be "where the action is." At the same time, there is a strong desire for what we have come to call the quality of life. Today, we all want the standard creature comforts. We want to be able to move freely

Jan 1, 1974

By J. Liniecki, w. Chruscielewski, T. Domanski

INTRODUCTION Mining is the Polish greatest industry employing about 350 thousand miners in more than a hundred underground mines. The mining regions are located mainly in the south of the country - see Fig. 1. [ ] The coal mining dominates, however, and the zinc-lead and copper-ore mines presently employ about 16000 miners. All these mines are rather deep and wet. Their drawing shafts are between a hundred to more then thousand meters deep. The cross-adit of working area of mines ranges from several kilometers to a few tens of kilometers. The numbers of mines per mine differ also considerably and depend on the territory and type of mines. The largest coal mines employ about ten thousand miners but the largest metal ore mines do not employ more than four thousand miners. In all the mines the electric motors or diesel engines are being used. The intensity of mine ventilation, characterized by the volume of fresh air injected in to the main ventilating shaft per miner and per unit of the power consumed by the engines is about 6 cubic meters per minute per man and per horsepower. The studies of the potential alpha energy of radon daughter products /RnDP/ could be divided into the three developmental stages: I-st - stage /1966-1970/ the stage of so called Pilot Survey. During this stage concentration of potential alpha energy of RnDP in the air was measured in selected typical mines in all mining regions of the country. II-nd - stage /1972-1974/ was the periodical control of concentration of potential alpha energy of RnDP in the air of zinc-lead and copper-ore mines which have been chosen and recognized during the first stage as being the most hazardous ones. Air-sampling system /ASS/ measurements were applied during this stage.

Jan 1, 1981

By Ramesh Kumar Chauhan, Umakant Sharma, Manwendra Pratap Singh, Ashok Kumar Chadha

The power sector in India has an installed capacity of 267.637 GW as on March 2015. Out of this total installed capacity, the hydropower sector contributes 41,267.43 MW as renewable energy source. The development of various proposed hydropower schemes in India are primarily concentrated in mountainous regions of Himalaya and often involves underground tunnelling. Underground tunnelling of considerable magnitude is generally associated with adverse geological conditions and associated geological surprises. The main objective in case of Tunnels constructed especially for hydro projects, which carry enormous quantum of water is that, it should not leak. Moreover, the tunnels which are part of water conductor system should resist the inflow of water from the surrounding ground in order to avoid draining of natural water sources and lowering of existing groundwater levels. Lowering of water table may result in subsidence and damage to existing surface structures, loss of capacity of drinking water schemes and in some cases even catastrophic sliding of landmass. Grouting and pre-grouting in tunnels serve three different purposes i.e., Stabilization, Strengthening and sealing of the rock mass around tunnels to avoid leakage of water from tunnels. In present paper, results of grouting methodology adopted during final construction stage of RHEP (412 MW) along with the introspection of Water Pressure Tests conducted for determination of the efficacy of grouting were elaborately presented. The process, of contact and consolidation grouting which is respectively followed by water pressure tests along entire reach of HRT (15.177 Km long) were also addressed in detail. Pertaining to the results of water percolation tests (before and after consolidation grouting), it was also attempted to categorize the behaviour of different rock mass classes/ conditions in reference to different quantum of grout intake and corresponding Lugeon values. Importance of planned and dedicated successful grouting procedure adopted in hydropower project at RHEP is also emphasized.

Jan 1, 2016

By Robinson Leon-Diaz, Alberto Jaen-Toribio, Raymond Blanchard, Mike Deevy, Miguel Fuentes-Llanos

"Tunnels designed to NFPA 502 are required to withstand the RWS time-temperature curve, more specifically prevent progressive spalling and loss of strength of steel reinforcement. Fire boards or spray-on layers can be effective, however, these solutions have capital and whole-life cost implications. The use of “fire resistant” concrete based on a suitable aggregate with polypropylene fibers has also increased in recent years. This article presents a new methodology for thermal and structural analysis of segmentally lined tunnels, which permits the analysis of project specific fire curves and an assessment of different fire protection strategies. The effectiveness of fire boards is assessed along with whether “fire resistant” concrete alone is a viable means of achieving the required protection. Finally, since NFPA 502 recommends water-based fixed fire-fighting systems for Category C and D tunnels, we discuss the question of how a fixed fire-fighting system should be addressed within the structural design. INTRODUCTION Protecting road tunnels from structural damage and collapse is a key requirement for both life safety and business continuity. Where road tunnels are part of key highway corridors, protecting business continuity is a high priority for owners, operators and the Authority Having Jurisdiction. For existing tunnels, compliance with NFPA 502 may require upgrades with either passive fire protection and/or water-based fixed firefighting systems. For new tunnels, compliance with NFPA 502 requires a combination of good practice in design and fire testing. A water-based fixed firefighting system is a Conditionally Mandatory Requirement1 for Class C and D tunnels, i.e. all tunnels greater than 300m and 1000m long respectively. The basis for fire safety design of new tunnels and assessment of existing tunnels is the worst-case fire scenario. A number of factors, including but not limited to the following, influence this design fire scenario:"

Jan 1, 2016

By Donald P. Richards, David W. Campo, Michel Coudry

This paper presents a review of the grouting works of Line 2 of the Greater Cairo MetroSystem. The Nile River alluvial deposits underlying this ancient city provided for a challenging and sometimes difficult grouting project. Permeation grouting using state-of-the-art computerized grouting techniques, as well as extensive ground treatment by jet grout, was per-formed for soil consolidation and/or groundwater control. During the project, over 425,000m3 of ground was treated, requiring 1.4 million linear meters of drilling and PVC injection pipe, 54,000 m3 of bentonite cement and 230,000 m3 of chemical and mineral grout. In addition, over 70,000 m3 of ground was treated using the jet grout method. Relative to major international transportation projects, the grouting works for Line 2 of the Cairo Metro represent one of the largest worldwide grouting endeavors to date.

Jan 1, 1997

By Duluth Engineers' Club, Engineers' Club of Northern Minnesota

"The early mining of iron ore in Minnesota was carried on with the most primitive kind of tools. The pioneers used only such equipment as could be packed from Duluth through one hundred miles of forest to the first mines on the Vermilion Range and the operations were carried on with picks, shovels, hand drills and wheelbarrows, the ore being hoisted in buckets with a horse winch and carted in horse drawn wagons to the stockpile. This was about the extent of the mechanical equipment of the Minnesota iron mines in the early eighties.As soon as a railroad was pushed through from Two Harbors to the Vermilion Range the equipment began to be improved upon; wood burning steam boilers were installed and small steam puffers displaced the horse-winches, wheelbarrows were aban¬doned and small cars were introduced. Hauling the hoisted ore in wagons was discontinued and trestles were built so that the ore could be stockpiled more cheaply through the use of cars and high piles. These same stockpiles were loaded by hand into the 10 and 15 ton capacity railroad ore cars.Within a few years a marked change took place—the hand drill gave place to the air drill, such as No. 3 Rands, Ingersolls, Sargents and some Sullivans. Tramming was done by mules, the ore hoisted in. self-dumping skips, hoisting engines were intro¬duced and it seemed as though mining as a business in Minnesota had come to stay. At this stage someone conceived the idea of making the stockpile floor about three feet above the top of the ore cars to facilitate the hand loading of stockpile ore for trans¬portation. This was done through the use of wheelbarrows at first and later by using I-ton cars running on tracks laid on the stockpile floor."

Jan 1, 1920

By M. C. Fuerstenau, J. J. Fitzgerald

Aluminum silicate hydrosol synthesis and characterization are discussed. Plausible polymeric aluminosilicate species are presented together with their effect on electrokinetics of selected minerals and flotation response of various ores. The addition of aluminosilicate hydrosol to porphyry and oxide copper ores and to a tungsten ore resulted in enhanced flotation recoveries ranging from about 1.5 to 5 percent. A significant portion of the nation's mineral resources are presently lost in the form of particles with very fine grain size. In the case of copper, for example, approximately 225 million tons of ore are concentrated by flotation per year in the United States. Total losses from porphyry ores are generally 15 to 20 percent with half of these losses being finely-divided copper sulfide minerals which do not respond to flotation. The additional 5 to 10 percent loss is the result of copper oxide minerals which are not floated. The losses of copper sulfide minerals are thought to be due in part to the lack of appropriate dispersion of the finely-divided solids less than 20 microns in size. To effect dispersion in flotation systems, sodium silicate is commonly added. Enhanced dispersion effectiveness is achieved when polyvalent metal salts are combined with sodium silicate. Since originally described by Patek (1), numerous workers have explored the utility of metal silicates. Makrousov (2), Belash et al. (3), and Eigeles (1950) (4) showed the applicability of these reagents to calcite/apatite and fluorite/calcite ores. Mercade (5, 6) reported depression of calcite in the presence of 3.33/1 mole ratio Al/Si hydrosols prepared from Type N sodium silicate (Si02/Na20 ratio 3.22/1) and 1% A12(SO4) 3•18H20 solutions. He importantly observed that the colloidal precipitates did not play a significant role in dispersion and depression but that the soluble species were responsible for this action. Patented work by this author described metal silicates used to depress calcite in scheelite flotation using 1% metal salt (FeSO4•7H2O, CoSO4•7H2O, etc.) and 5% Type N sodium silicate solutions to produce hydrosols with Si/Fe or Si/Co ratios of 8.79/1. Aluminum (III) ion systems were less effective as depressants than the iron and cobalt systems. Yang (8, 9) has studied metal silicate sols for use in the flotation of lithium and ultra-fine hematite ores. Using 10/1 Si/Fe mole ratio hydrosols prepared from 2% ferric nitrate, Fe(NO3)3.9H20, and 5% Type N sodium silicate solutions, solutions, he showed that the hydrosols either modify the slime particle surfaces or are adsorbed on the slime particles preventing anionic collector adsorption. In a subsequent patent, Yang also reported the use of these hydrosols as dispersants for beneficiation of lithium ores. Recent studies of aluminum silicate hydrosols in the flotation of chalcocite, chalcopyrite and scheelite have been reported using Si/Al dispersants prepared from 5% Type N sodium silicate and 0.1 M aluminum chloride (A1C13.6H20) solutions. Dispersant properties were shown to be dependent upon the method of synthesis, supernatant pH, and the hydrosol Si/Al mole ratio. Polymeric soluble species in these hydrosolsupernatants have been proposed as the active dispersant species. Aluminosilicate hydrosols are synthesized by the general reaction scheme presented in Figure 1. Commercial sodium silicates are available with ratios of SiO2 to Na20 of 1.60-3.25. The sample which is most frequently employed is Type N whose ratio of Si02/Na20 is 3.22/1.00. Gel filtration chromatography and NMR studies have shown that these sodium silicates contain numerous species of molecular weight from 325-2,000 gm/mole. Monomeric, oligomeric and higher molecular weight linear polymeric arrangements of these structures are found in these solutions.

Jan 1, 1989

By John F. Shea

When Dick Robbins asked me to give a keynote address, I felt it might be in order to review some of the practices and techniques used in tunneling and work up to some of the concepts now used to mine and construct tunnels. Needless to say, there have been many changes in tunneling technology and also many changes in the Safety Codes controling them. An example of this latter change was the fact that in 1931, my father excavated the Owyhee Tunnel No.5 with gas locomotives. He was able to do it because there was no natural gas in the rock and the ventilation system was designed to free the tunnel atmosphere from powder and exhaust fumes. Today OSHA rules would never permit gas locomotives underground, although there were no incidents on this particular project. One of my first tunnels, as Project Manager, was the Clear Creek Tunnel for the Bureau of Reclamation. Our method of handling muck was the Conway Muckers. This unit was a valuable improvement to the hand mucking of previous generations. The Conway was also used in our Navajo Project, in New Mexico. Unlike the Clear Creek project, where water was one of our main problems - up to 7,200 gallons per minute, at a pressure of 395 pounds per square inch - in the Navajo Tunnel, we had a mixed face which caused a major problem with our support system. In one of the Navajo Tunnels, there was a major cave-in, when the squeezing shale came in during an attempt to strengthen the support system. Although moving shale was not a constant problem, there were areas where the shale was five to six feet above the spring line.

Jan 1, 1976

By Jeroen van Eldert, Daniel Johansson, Henrik Ittner, Håkan Schunnesson

"Numerous aspects of underground construction, from structural stability to construction costs, depended on the tunnel quality, including blast damage and the Excavation Damage Zone. Accurately quantifying the extent and severity of damaged rock is a problem. Recent technical developments in the field of Measurement While Drilling (MWD), including software for on-board logging and on-site analysis, have shown potential for rock-mass characterization. Ground Penetrating Radar (GPR) and P-wave velocity measurement have also improved and show similar potential. This paper explores the use of MWD, GPR and P-wave velocity measurements and uses them in techniques for excavation damage characterization and prediction. The paper is based on data collected from a small underground waste-collection site in central Stockholm, Sweden. The data is correlated against rock-mass characteristics and their responses are evaluated. Results indicate potential for excavation damage characterization for all tested techniques, which could minimize blasting damage and improve the over-all tunnel quality. 1 INTRODUCTION During underground excavation the rock mass is influenced in many ways. The Excavation Damage Zone (EDZ) is a result of these influences. The EDZ can be defined by an irreversible change in rock mass properties, for example increased permeability. EDZ is influenced by the excavation method, the rock mass properties and the in-situ stresses in the area of the tunneling. Since the 1990s research has been done on the EDZ by Emsley et al. (1997), Christiansson et al. (2005), Olsson et al. (2009), Ouchterlony et al. (2009), Ittner et al. (2014), and Siren et al. (2015). Based on past literature the EDZ have in this paper been separated in the following subzones: 1. Failure Zone or over-break is the area outside the planned tunnel profile, including the Look-Out and hole deviation. This zone consists of fracture networks (both natural and blasting-induced), that caused rock fall-outs. The extent of the over-break can be determined by volumetric scanning and photogrammetry and the half cast factor can be used as a damage indicator. 2. The Damaged Zone is split into three parts and but the quantity and depth of damage is difficult to measure. Although it can be visualized by sawing of rock slices in the tunnel wall (Olsson et al. 2009), diamond coring (DC) or P-wave velocity reduction (Jern 2001): a. Inner Damage Zone (Crush Zone): It is located directly around the drill hole, and is caused by the shock-wave energy of the detonation. The micro fractures in the Crush Zone produce a white-wash (rock dust) in the half cast. b. Transition Zone: This zone consists of micro fractures that connect and form macro fractures, both radially and parallel to the tunnel wall. The macro fractures are caused by the gas expansion during the detonation of the explosive; it increases the pressure in the (micro) fractures and creates the macro fractures. Seismic reflection, rock slicing and core drilling can be used for the examination. c. Progressing Zone: In this zone the existing radial fractures propagate due to the increase gas pressure inside these macro fractures. Examination methods are seismic reflection, rock slicing and core drilling. In addition, the Peak Particle Velocity (vibrations) could be used to estimate the depth (Tesarik et al. 2011)."

Jan 1, 2016

By C. J. Pritchard, R. D. Jacksha, K. V. Raj, C. Sunderman

"In underground metal/nonmetal mines, repeated short-term exposure to high levels of airborne contaminants can become a serious health issue. Currently there are no common mechanisms to control or mitigate these localized short-term high exposures to contaminants. To improve miners’ health and safety, the National Institute for Occupational Safety and Health (NIOSH) Spokane Mining Research Division (SMRD) is developing a Smart Monitoring and Control (SMAC) system for real-time monitoring of mine air quality, with integrated countermeasures to reduce these high concentrations of airborne contaminants in localized sections of mines. To develop and test a SMAC system that could be implemented in an underground mine, researchers at SMRD built a test apparatus incorporating a fan, louver, ducting, and sensors combined with atmospheric monitoring and control software. This system will institute effective countermeasures to reduce contaminant levels, improving miner safety and health. INTRODUCTION Underground metal/nonmetal mines continue to expand production by employing large equipment in greater numbers and by mining into hotter and more challenging environments which are typically further away from fresh air sources. This challenges the ventilation system to provide adequate quantities of fresh air to the workplace and increases the potential for air contamination that could result in immediate and long-term health and safety issues to miners. Currently, airflow and contaminant concentration in mines are typically based on full-shift sampling which may not identify repeated short-term exposures to high levels of airborne contaminants such as NO2, CO, diesel particulate matter (DPM), and dust with high silica contents. Repeated short-term exposure to these high levels of airborne contaminants over long periods can lead to serious health issues which are documented in several studies [1-3]. Based on data from ventilation surveys and contaminant measurements, mines often attempt to minimize exposures by sending more fresh air to the working areas where contaminant concentrations are found to be high. Real-time monitoring and control allows mines the option to monitor contaminants and implement controls in real-time. Real-time monitoring and control of the underground mine atmosphere has been a subject of research since its beginning in Finland at Outokumpu’s Pyhäsalmi Mine in 1969 [4]. More recently, the real-time monitoring and control problem has been addressed using ventilation on demand (VOD) systems [5, 6]. A VOD system attempts to deal with this issue on a global level by controlling fans, louvers, and doors to increase airflow to active work areas and reduce contamination. However, a VOD system only controls the distribution of airflow and may not be helpful in mines where the airflow is at maximum capacity. Researchers at SMRD are developing a SMAC system for real-time monitoring of mine air quality with an integrated ability to trigger countermeasures to reduce high concentrations of airborne contaminants in localized sections of mines. The SMAC system will be designed, tested, and refined in the laboratory environment before being demonstrated in an underground mine. This system will not only try to minimize the gaseous contaminants by regulating the airflow locally, but will also potentially employ a filtration system to reduce the airborne contaminants in case the maximum airflow capacity is reached. This paper presents development of the test apparatus for the SMAC system."

Jan 1, 2017

By Charles G. Frush

The function of the mine surveyor is to (a) provide a network of points of accurately known position, covering the entire mine property, (b) obtain the required data for the preparation of useful maps and sections! (c) provide position and directional control for the guidance of the operations, (d) measure the progress of the work, (e) measure the movement of rock masses, and (f) make miscellaneous surveys as needed. Mining properties range from the very small to the extremely large, and from those which involve only surface operations to those involving extensive underground workings. Active mines undergo constant change, necessitating continual updating of the surveys. The differences in the character of the deposits, the scale of mining and the mining methods result in large differences in the surveyor's activities and techniques, but many of the problems involved are common to most mines. The surface work of the mine surveyor is very similar to that, of the plane surveyor in that control points are established by triangulation, trilateration and traversing. Detail is taken by direct measurement, by stadia and by aerial photography. The equipment used, the techniques and the methods of processing the resulting data are likewise very similar. However, the underground work is quite different : A. The lines of sight frequently must be carried through constricted openings, often involving short lines of sight and awkward setups. B. The lighting often is poor, requiring illumination of the backsights and foresights, and the crosshairs. C. The ambient conditions often are difficult, involving falling water, high tem- peratures, poor visibi 'kv and heavy traffic through the area being suneyed. D. The surrounding rock map be unstable, resulting in movement or loss of the surveying stations, as well as hazard to the surveyors. E. The points to be measured often are difficult or impossible to reach. F. Steep vertical sights often are necessary, requiring the use of special equipment. G. Many working levels commonly are involved, requiring the transfer of position and orientation to each with a high level of precision. This section therefore will concentrate on surveying problems peculiar to the mine surveyor, chiefly underground work. 22.1-THE MINE COORDINATE SYSTEM A system of coordinates is essential for all permanent mining operations It is very desirable that all mining operations in a ,given area b~ tied into the same system, as this minimizes problems of boundaries and connections Whenever possible this system should be tied into and made part of the state or regional grid system. It is desirable to orient the coordinate grid on a true-north line and to position the origin of the coordinates so that all of the work will be in the "northeast" quadrant, making the north and east coordinates always positive. This can be done by subtracting suitable constant values from the north and east coordinates of the regional system The residual values are of more convenient magnitude and can be used as the local mine coordinates. If the long axis of the mineralization is not generally north-south or east-west.

Jan 1, 1973

By D. P. Patil, T. C. Rao, J. P. Barnwal

Factorial design of column flotation experiments was used to understand the main and interactional effects of the column parameters. In the experiments, the air flog rate, the wash-water, flow rate and the froth depth were varied at two levels. Analysis of the results showed that an increase in airflow rate had a deleterious effect on the grade of the concentrate, whereas, an increase in froth height increased the grade. The interactions between airflow and wash water and between airflow and froth height were significant with respect to grade of the concentrate. These results demonstrated that, from an ore containing 12.76% P2O5, it is possible in a single-stage flotation column to obtain a concentrate containing 31 % P2O5 (10.6% Si02) with a recovery of 94%, thus reducing the number of cleaning stages that would be required if conventional flotation cells were used.

Jan 1, 1997

By Leonid Pevzner, Valerie Dmitriev, Yuri Babitchev

Performance of belt conveyors, service life of belts and mechanical elements can be radically improved if the automatic adjustment of the belt speed movement is made in such a way, that the unit load over the conveyor length be constant and close to the rated one under random input freight traffic. Such an adjustment is possible when the system of a controllable thyristor electric drive on the basis of induction squirrel cage motor is used. Computer-aided adjustment of the belt conveyor movement is effected via bicontour digital control of the main drive in order to redistribute loads when the loading of conveyor and contour of the control of tension drive are changed. The system envisages control and condition monitoring of the conveyor electromechanical system, as well as metering of electrical power and the amount of conveyor freight. The results of the simulation of speed control of the conveyor belt are given in the report. Mathematical model of the conveyor electromechanical system describes the movement of the belt with cargo and the tension drive. The input cargo traffic is assumed as stationary ergidic random process with the assigned characteristics. The solution of the problem of the synthesis of a closed-loop control system, the structure and parameters of adjustment, the conditions of asymptotic stability of the control back-up system and the condition of minimization of mean square error of shadowing are also given in the report. Microprocessor controller is used to realize the function of the adjustment unit. Under this control system standard mode of conveyor operation, different modes of start-up, operating mode with decreased speed when transporting people, service and emergency braking of a conveyor and some other modes are realized. The digital model of a conveyor as an instrument for decision making in case of emergency is used in those modes. MASTER TEXT Long-standing practice of belt conveyor operation in mines of Russia has proved their inefficient use with 40-70% capacity and 20-25% availability factor. It is associated with unreasonable power intensity and reduction of service life of mechanical components, and as a result, with the growth of total transportation costs. Low efficiency of conveyor application can be explained by the extremely irregular distribution of conveyor freight traffic. Usually, the width of a conveyor belt is identified in accordance with the possible maximum traffic value, engine power capacity for long-term operation under rated loads. However, actually a conveyor often runs without any load and its average load in most cases is lower than the rated one. The problem can be eliminated by way of the adjustment of the operational mode of a conveyor according to an actual input freight traffic via belt speed control providing for the conveyor regular linear load which is nearly equivalent to the rated one. Experimental research into freight traffic under working conditions of the operating underground and open-cast mines proves the fact that the actual freight traffic can be adequately presented through the model of stationary random function of time, for ex- ample, as a J (t) continuous random Gaussian process that is modulated with a G(t) elementary pulse flow:

Jan 1, 1996

By Zeynep Aktuna

In this study, the formation of zeolites around Kizkapan and Karlikoy villages (Sothwest Kesan) were investigated. In this region, stratigrafically, Upper Eocene Kesan Formation, i.e. sandstone and rarely shale are observed at the bottom. Early Middle-Oligocene Yenimuhacir Formation is composed of sandstone, marl and tuffs. The zeolitisation is determined in the dasitic tuffs of the Yenimuhacir Formation. In this tuffs' zone, alteration had primarily resulted in zeolites, mainly mordenite, heulandite-clinoptiIolite. Silicification and alteration to clay minerals are also common. The Miocene-Pliocene Ergene Formation and alluvium deposits are the top units in the area. In the studied area, zeolite occurences have economic importance. The results show that successively rapid and short term periods are responsible for the clinoptilolite-heuylandite formations. The homogene chemistry of the solutions may be evaluated for a possible successive zeolitisation period. Multi-periodic vocanic activity and also circulation of thermal water had resulted in a continous dissolution of volcanic glass; moreover, resulted in the formation of suitable conditions of zeolite formation. The mineral crystallization sequences and alteration products as zeolites within the wall-rock, circulated solution reaction depends on a serie of parameters such as chemical composition of both initial materials and volcanic solutions during rock¬solution interaction period. The previous researches and the chemical studies support our results and observations in the studied area. The aim of this study is to investigate the presence of zeolitisation and to explain the formation steps of zeolitisation in Kesan Area by considering the content and distribution of major and minor elements determined in zeolite bearing tuffs. The chemical structures of both zeolite bearing volcanics and zeolite minerals are compared to the results of previous studies. Two dimentional behaviours of major and minor elements were discussed in order to caracterize zeolitisation development and to postulate a probable formation type of zeolitic alteration.

Jan 1, 2005

By D. H. Carlson, J. H. Johnson, C. F. Renders

Research was conducted at a western coal mine on a wide variety of underground mining vehicles to develop testing procedures for portable instrumentation monitoring of tailpipe concentrations of diesel particulate matter (DPM), carbon dioxide (CO2) carbon monoxide (CO) and nitric oxide (NO). DPM was measured using the Emissions Measurement Appa¬ratus (EMA) developed by Michigan Technological University (MTU), and an ECOM-KL five-gas analyzer was used to measure gaseous tailpipe concentrations. Baseline concentrations of the tailpipe pollutants were measured using vehicle systems to load the engine. Concentrations before and after the water scrubber were measured and water scrubber efficiencies were estimated by calculation. Field measurement procedures were established. Heavy-duty vehicles with automatic transmissions were loaded using the torque converter to stall the engine. Consistent engine loading for light-duty vehicles with manual transmissions involved placing the transmission in neutral and adjusting the throttle to maintain a constant engine speed of 2,500 rpm. Tailpipe CO2 concentrations for Caterpillar 3306 and 3304 engines were compared to laboratory CO2 data from Caterpillar and MSHA to help determine if engine settings were correctly adjusted for operation at high altitudes. (Perfect agreement between the mine vehicle tailpipe and laboratory measurements would not be expected because of the differences in the test conditions.) DPM concentrations for light-duty vehicles ranged from about 20 to 160 mg/m3, and one light-duty vehicle averaged near 1,000 mg/m3. DPM concentrations for heavy-duty vehicles ranged from about 55 to 200 mg/m3. Widely ranging DPM concentrations for a particular vehicle type reflect the state of maintenance, fuel rate settings and different engine loading procedures as well as differences between samples collected upstream and downstream of the waterscrubber. The calculated DPM removal efficiencies due to the water scrubber varied considerably between vehicles, ranging from 13% to 51%. Calculations indicate that, under worst-case conditions, very large reductions in DPM may be required to meet the proposed DPM PEL of 0.15 mg/m3, even on vehicles with water scrubbers. In-mine ambient air studies, which are needed to actually measure the impact of the tailpipe concentrations on the work environment and the effect of mine ventilation on the dilution of DPM were not done in this first set of tests.

Jan 1, 2000

By Malcolm Ross

Of the six forms of asbestos, only three have been used to any significant extent in commerce. These are chrysotile, crocidolite, and amosite. Between 1870 and 1980, approximately 100 million tonnes of asbestos was mined worldwide, of which more than 90 million tonnes was the chrysotile variety, about 2.7 million tonnes the crocidolite variety, and about 2.2 million tonnes the amosite variety. The three principal diseases related to asbestos exposure are (1) lung cancer, (2) cancer of the pleural and peritoneal membranes (mesothelioma), and (3) asbestosis, a condition in which the lung tissue becomes fibrous and thus loses its ability to function. These diseases, however, are not equally prevalent in the various groups of asbestos workers that have been studied: the amount and type of disease depend on the duration of exposure, the intensity of exposure, and particularly, the type or types of asbestos to which the individual has been exposed. Lung cancer is caused by exposure to chrysotile, amosite, and crocidolite asbestos; however, increased risk of this disease is usually found only in those who also smoke. Asbestosis is caused by prolonged exposure to all forms of asbestos, whereas mesothelioma is principally caused by exposure to crocidolite asbestos. There is good evidence that chrysotile asbestos does not cause any significant amount of mesothelioma mortality, even after very heavy exposure. The common nonasbestiform amphibole minerals, cummingtonite, grunerite, tremolite, anthophyllite, and actinolite, which are often defined as "asbestos" for regulatory purposes, have not been shown to cause disease in miners. Chrysotile asbestos, which accounts for about 95 percent of the asbestos used in the United States, has been shown by extensive Canadian studies to be safe when exposures do not exceed 1 fiber per cm3 for the working lifetime. Chrysotile dust levels found in buildings rarely exceed 0.001 fibers per cm3. Such dust concentrations will have no measurable health effect on the building occupants. Present and future controls of minerals defined as "asbestos" and removal of asbestos from buildings and homes may cost many billions of dollars. Much of this expense is unnecessary and even counterproductive. Asbestos abatement could in fact produce a health risk to those exposed to dusts during and after removal operations overly restrictive controls could force the use of poor or dangerous substitutes, and could greatly affect the hard-rock mining industry.

Jan 1, 1987