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By George R. Stephans

The Climax Mine is a panel caving mine which has had a long history of incidents of severe ground control problems. The nature of the ore deposit, which lends itself to the caving meth- of of production, a1 so makes the mine susceptible to large scale stress concentrations which are referred to as ?weight? problems. These problems have increased with increased production and also with expansion to deeper mine levels. During the past twenty years the mine has had to learn to cope with these problems in order to remain in operation. A number of practical guidelines and useful techniques have emerged from these efforts. The purpose of this paper is to share a few of these ideas. The Mine is located near Leadville, Colorado on the continental divide at an elevation of 3450 meters. The ore body is a large low grade deposit of disseminated molybdenum sulfide. It measures about 1200 to 1600 meters in diameter and it had an original depth of about 660 mters. The Mine has been in operation since 1918 and the massive nature of the ore body together with its blocky, highly fractured condition made it natural for the caving system to have been adopted for production at an early date. Open pit mining was started in 1973. The total plant has a capacity of more than 50 thousand tons per day, and more than 400 million tons of reserves at an average grade of 0.310 percent molybdenum disulfide remain to be produced.

Jan 1, 1982

By Ziyuan Liu, Xun Zhang, Yan Wei, Hang Qiu, Shaomin Lei, Yubiao Li, Yu Meng, Min Lin, Bin Liu

High-purity quartz (SiO2) is an important material widely used in many industries, including semiconductor technology, telecommunication, and optics. The content and distribution of impurities in quartz significantly affect the processing methods. This paper provides an insightful review on the processing of high-purity quartz, covering the analytical techniques, separation methods, and the critical procedures used to assess the quality of quartz ore. More importantly, the critical review of the thermal phase transition separation method for fine-grained mineral inclusions, micron-grade fluid inclusions, and lattice-bound trace elements is notably opened for the first time. It is proposed that the research field as a monopolized industry would benefit by expounding the critical problems that occur during the preparation of high-purity quartz.

Jun 22, 2020

By L. J. Buchanan

The relationship between hydrothermal ore deposits and hot spring systems has received intensive study in recent years, particularly as a consequence of interest in the energy potential of geothermal systems. Base and precious metal deposition in surface pools and at shallow depths in modern geothermal systems has been recorded in numerous publications (1, 2, 3) Theoretical studies of hydrothermal fluid flow at depth, connected to surficial hot springs systems, have been presented by White and others (1), Cathles (2) , Henley and McNabb (3). As a result of these and additional studies, numerous hydrothermal ore deposits are thought to have originated as genetic parts of larger geothermal systems. In particular, it appears that metal precipitation is greatly enhanced in zones of boiling where volatiles and steam are escaping (4). High grade, near surface concentrations of base and precious metals, deposited as a result of partial vaporization of rising fluids, are such a common aspect of modern not spring systems that ore deposition models are becoming based on what may be called a geothermal model. In its most general terms, this model requires an anomalously high thermal gradient which acts as the driving force behind a convecting hydrothermal system. The water may be entirely meteoric or may be In part at least of other origins. The water migrates towards the higher temperature area, becomes heated, and picks up alkalies and metals by dissolving minerals along the fluid path. As water exits to the surface above the heat source, a mass balance requires the incoming hot water to rise to replace the lost water. As the water rises past the elevation where the hydrostatic pressure is insufficient to prevent boiling, then boiling will occur. Depending on the salinity and the temperature of the water, boiling can occur anywhere from great depths to near surface. Boiling results in a loss of volatiles, a pH rise in the fluid phase, cooling of the remaining fluid, a rise in oxygen fugacity, a concentration of salts in the remaining liquid, and precipitation of ore and gangue minerals.

Jan 1, 1980

By David T. Swanson

The term "pressure tunnel" in the broad sense includes all hollow spaces, aligned along an axis and surrounded by rock, which are suitable for pressurization. In particular, this category includes: • horizontal or slightly inclined water pressure tunnels; • vertical or inclined pressure shafts; • pressure chambers or shafts of surge chambers; and, • compressed air storage tunnels. The main problems in the design and construction of pressure tunnels result less from their length or size than from the requirement for watertightness and, dependent upon this, reliability in operation and economy in construction. Where the lack of sufficient overburden does not permit the rock to accept the internal pressure in the tunnel, or where this pressure is so high that the watertightness is in doubt although the stability of the tunnel shell is not in question, a pressure tunnel must nevertheless be reinforced. Surge chambers, pressure tunnels and tailraces which are subjected to relatively low internal pressure, usually not much in excess of 1.5 MN/m2, are eminently suitable for construction in post-tensioned concrete. Pressure shafts, which as a consequence of the high water head are subject to a considerable maximum service pressure, are usually lined with a steel tube, a considerable proportion of the internal pressure being transmitted to the rock by backing concrete. TYPES OF LINING FOR PRESSURE TUNNELS In general, the type of lining will depend upon the nature of the rock. As a result, pressure tunnels usually are not uniform in con-

Jan 1, 1981

By T. S. Golosinski

Most of the 154 t (170 st) truck fleets that were predominant in large surface mines in the 1970s and 1980s are approaching the end of their economic life. One replacement option considered by mine operators is a change to the 2 18 t (240 st) trucks. A comparison of load capacities between the 1.54 t (170 st) and the 2 18 t (240 st) trucks indicates a large productivity advantage in favor of the 218 t (240 st) trucks. This advantage, however, is often reduced by a number of site-specific factors. Therefore, a careful evaluation is required to define the actual benefit of changing to the large trucks. This article discusses some important factors that have an impact on truck size selection, based on several different studies. 218 t (240 st) trucks The 2 18 t (240 st) rear dump trucks were first introduced for surface mine service almost 10 years ago. However, it is only during the last few years that this equipment has gained acceptance in the surface mining industry. About 250 units were employed in surface mines worldwide at the beginning of 1992, and further purchase commitments are being made. Encouraged by the mining industry’s interest, all major off-highway mining truck manufacturers now offer 218 t (240 st) models (Table 1). At present, the existing 218 t (240 st) truck fleets are dominated by electric drive trucks. However, recent introduction of a 2 18 t (240 st) mechanical drive truck rounds out the development of this truck size.

Jan 1, 1992

By James M. Murphy

INTRODUCTION In the fall of 1983, the fourth new Rapid Transit System constructed in this country in the last forty years will go into revenue service. The Baltimore Metro will bring to this major Mid-Atlantic seaport the first phase of a planned intermodal transit system, serving a metropolitan area with a population in excess of four million people. Originally, the Mass Transit Administration (MTA) considered construction of a twenty-eight mile system known as Phase 1. Its two lines would run from the center of Baltimore City, one going northwest to Owings Mills and the other south to Anne Arundel County. Legislative approval was granted in April, 1976; however, funding was limited to constructing a segment fewer than eight miles in length, along the northwest corridor from Charles Center to the Baltimore City county line. This segment is known as Section A. The project is 80% federally funded and 20% state funded, with a capital cost estimate of $797,000,000 to complete. This report addresses the development and implementation of a Coordinated Insurance Program for the construction phase of Section A, and includes a description of the associated risk management process. GENERAL DESCRIPTION OF SECTION A Section A of the Baltimore Metro is composed of a rapid transit line eight miles in length which serves the northwest corridor between Charles Center in downtown Baltimore and Reisterstown Plaza at the Baltimore City county boundary. The line is completely grade separated and, once operational, will provide high speed automated rapid

Jan 1, 1983

By Trevor A. Moss

Installation of equipment and structures at mines often requires mine planners to evaluate unique loading and operating conditions. Consideration of these unusual features is required throughout design and construction and into operation. Most planners understand the necessity of employing sound civil, structural and mechanical engineering techniques to design these structures and equipment. However, the influence of geotechnical factors on the overall progress of construction and operation is less appreciated. Mine operators routinely perform exploratory drilling to define ore deposits. These exploration activities can be extensive and often include provisions for assessment of subsurface conditions as they relate to the mining operation - requirements for ground support. All of these factors are important to the economics of the mine and are well justified. Surface facilities are provided to access and service the mine, and they play an important role in the successful development and operation of a project. Headframes, hoist foundations and shaft collars, in particular, are examples of unique installations encountered at underground mine sites. The design and above-surface behavior of these facilities can be analyzed with the usual fundamental engineering practices employed throughout the engineering professions. However, near surface exploration for the purposes of assessing soil and rock conditions for foundations is often given a reduced priority and less consideration. This article provides an outline of the benefits and importance of performing such exploration. References here relate particularly to shaft headframes, hoists and shaft collars. But the issues raised apply equally to other installations of a similar nature, including milling equipment.

Jan 1, 1992

The US Geological Survey (USGS) held a one-day workshop at its Denver, CO facility to inform the public of the status of its National Mapping Program. In addition, the agency wanted to obtain information from topographic map users on what their needs are. The agency wants to know what the topographic map user wants. The USGS faces the challenge of keeping up with the changing needs of the nation. In the last few years, the agency has changed dramatically to meet these needs. For example, the "new" USGS incorporates mineral-information specialists from the former US Bureau of Mines and also uses the expertise of former National Biological Service employees. These areas complement the agency's traditional strengths in mapping, geology and water re- sources. The stated mission of the USGS's National Mapping Division is to "meet the nation's need for basic geospatial data, ensuring access to and advancing the application of these data and other related ears science information f& users worldwide." To accomplish this goal, the USGS publishes topographic maps, including shaded-relief editions of areas of special interest (state maps and national parks); photo image maps; satellite image maps; geologic maps and hydrologic maps. The geologic maps include geologic quadrangle maps, oil and gas investigation maps and charts, and coal investigations maps. The familiar 7.5-minute series topographic maps are the most widely used. The 7.5-minute- (1:24,000-scale-) format mapping was begun in 1935.

Jan 1, 1998

By Philip U. Santacroce, James H. Meinholz

INTRODUCTION The Milwaukee Metropolitan Sewerage District (MMSD), is a special purpose sub-regional agency that provides collection and treatment services for sanitary wastewater for an area of 420 square miles (1088 km2) in 27 municipalities in the Milwaukee, Wisconsin metropolitan area. During its almost 75 years of existence, it has constructed 464 km of intercepting sewers, the majority in tunnel, and two sub-regional secondary wastewater treatment plants. The present program, the $1.7 billion Milwaukee Water Pollution Abatement Program, was started in 1977 and developed from ongoing internal planning, the Federal Clean Water Act and court judgments. Elements of the Program include improvement and expansion of the two treatment plants; rehabilitation of older in-place sewers; building new interceptors and relief sewers and providing capacity for high volume storage in approximately 32 km of deep, large diameter rock tunnels; reducing combined sewer overflow; and disposal/utilization of the solids that remain after the treatment process. The construction phase of the Program accounts for $1,105,900,000 within 335 separate construction contracts, 211 let to date, and covers a span of 15 years, starting in 1979 and running through 1994. Conveyance System construction cost is estimated to be $650,000,000 or about 60 percent of the total. Through December 1986, in terms of dollars, the total construction program is about 38 percent complete with Conveyance at 34 percent complete.

Jan 1, 1987

By Krishniah N. Murthy, James E. Monsees

BACKGROUND The development of public transportation in the Los Angeles Metropolitan area is, as in other cities, closely tied to the development of the area because of increases in population and commercial and industrial activity. Local transportation first appeared in the area in the 1870s when the population was fewer than 10,000 residents. Around 1910, after many consolidations of competitive interests, two large railway companies were formed: The Los Angeles Railway, which provided urban transportation in the Los Angeles City area, and the Pacific Electric Railway, which primarily provided suburban and interurban transportation. These two entities continued with their operations until after World War II, when the ownership passed on to the Los Angeles Transit Lines and the Metropolitan Coach Lines, respectively. By then the railroads needed new equipment, track rehabilitation, and, of course, more money-paying patrons. Lack of grade separation of railway facilities from other traffic increased commute times and encouraged travel by private automobiles. The romantic era of hopping on a Pacific Electric Company "Big Red Car" was coming to an end. As early as 1917, in fact, bus lines were substituted for unprofitable rail service. The Los Angeles Metropolitan Transit Authority (LMTA) was established in 1951 by the California Legislature to study and plan for improvements in the public transportation facilities in the Los Angeles area. In March of 1958 the Los Angeles Metropolitan Transit Authority took over the operation of the two lines.

Jan 1, 1989

By John A. L. Dr. Campbell, James W. Haskew, F. Hoy Lee, Elliott P. Dr. Doane

Emissions of particulates, unburned hydrocarbons, nitrogen oxides (NO[ ]) and carbon monoxide (CO) from diesel engines are of concern in mines, particularly underground mines. All these undesirable products except NOx are the result of incomplete combustion in the cylinders. Various approaches to achieving more complete combustion in diesel engines have included different fuel compositions, use of catalysts, fuel additives, engine modifications, and oxygen-enriched intake air. The present study shows that injecting minute quantities of primarily platinum group metal catalysts into the intake air of a Deutz/MWM D916-6 mine diesel engine substantially reduces emissions in the exhaust. The catalyst injection system, which was developed by National Fuelsaver Corporation (Robin. 1981), transfers catalyst compounds in solution to a stream of air bubbles by a process called Bubble Fractionation (Lemlich et al.. 1966, 1968. 1970). The amounts are so minute that concentrations in the engine exhaust should be well below OSHA/NIOSH Time Weighted Average (TWA) exposure limits at steady state, a fact that was confirmed by analysis of collected particulates in the exhaust. When the catalyst injection was used along with a pleated paper filter to remove exhaust particulates, the filter operating life was shortened greatly. Therefore, this system is not recommended for use on diesel engines equipped with a water scrubber and a filter. It does offer a practical and relatively economical way of reducing exhaust emissions from other diesel engines, such as those in outby mine service

Jan 1, 1995

By John J. Rhodes

I welcome this opportunity to give a Congressman's birdseye view of a subject which I believe holds great potential for the future in helping meet the needs of people, with minimal adverse impact on the environment. All mankind, not just the people in this great nation, faces the need for additional usable space. In some parts of the United States the problem arises from rapid urbanization of the surface and little utilization of the subsurface. Everywhere there is an increasing problem of insufficient space arising out of the increasing population crush and growing demands for open space, housing, water, transportation, communication, and social service. You are the technicians to whom we look for assistance in finding answers. We look to you also to provide guidance for broad policy decisions concerning underground space. I prepared for a career practicing law, but since 1952 I have been a member of the House of Representatives. In this latter capacity I deal with programs designed to help solve all kinds of problems. But, naturally, I am especially interested in the water scarcity and other environmental problems of my home state of Arizona and the arid and semi-arid areas in the West. This North American Rapid Excavation and Tunneling Conference has as its theme: "Tomorrow's Tunneling Technology Today." I have a very great interest in this potential of our underground space resource. The Central Arizona Project now getting underway in my state will consist in part of tunnels and underground pipelines to convey life-sustaining water from the Colorado River to people and lands across Arizona to the Phoenix and Tucson areas.

Jan 1, 1997

By K. Rüter

Sustainable investment is a global growth market. Companies that can reconcile economic, environmental and social objectives not only minimise risks, but also realise significant potentials of added value. This particularly applies to the metals & mining industry, as it is an attractive sector for investors and, at the same time, faces major challenges in the field of sustainable development. oekom research AG is an independent rating agency specialised in the analysis and evaluation of the environmental and social performance of companies, sectors and countries for institutional investors and financial service providers in the socially responsible investment (SRI) sector. oekom research has been active in the sustainable investment field since 1993 and its research is currently being used by managers of more than 60 bond and share funds with a volume of assets totalling more than 4.5 billion Euro. The company?s research and its central instrument, the Corporate Responsibility Rating (CRR), are based on the world's most comprehensive set of criteria for the ethical assessment of companies. With the support of an independent scientific advisory board, these universal and industry-specific sustainability criteria are being constantly updated reflecting the dynamics of global challenges in sustainable development. Increasingly, the rating results and benchmark reports of oekom research are also being recognised by the companies as a valuable tool to identify best practices, areas for improvement, and potential risks. This paper will outline the methodology of oekom research, the identification of key sustainability issues in the metals & mining industry, the development of industry-specific sustainability criteria (indicators) for the assessment of the metals & mining industry and key findings of the recently completed CRR of twenty major metals & mining companies.

Jan 1, 2007

By M. Rîsteiu

The authors aim to analyze the behavior of smart sensors using Transmission Control Protocol/Internet Protocol (TCP/IP) infrastructure in hazardous applications, because of their advantages regarding safety, expansion and Quality of Service (QoS). Initially, some constraints are discussed for these applications. Then, the possibility is analyzed of using 2.4 GHz TCP/IP based transmission for sending data out of an industrial area. In this setup the authors evaluated the round-trip implementation (which requires a database of packet lengths), related to the delay introduced by the radio transmission algorithms from 802.15.4, and 802.11d/g protocols. Tuning results of different varying time-delays were compared to the constant delay cases from the literature (Deák, 2003; Lincoln, 2003). Both the hardware and software setups are implemented. Based on TinyOS specific software for hardware checking/ initiating communication/ starting/ closing measurements the authors have developed separate/combined procedures for testing the integrated devices. Measured time delay is presented and analyzed, for both beaconed and non-beaconed 802.15.4 transmission, with power optimization criteria. By testing two different implementations (Zhang et al., 2001), (ATmega256 RZAV - 256KB flash memory, the CC2420 IEEE 802.15.4 and ZigBee-compliant RF transceiver core - 128KB flash memory) the authors have found some time delay variations as a result of local processing by the ZigBee controller with an amount of flash memory. The work is also focused on adapting industrial measuring standard systems to the smart sensors, but not only through the 4-20 mA standard.

Jan 1, 2008

By Steve Kral

When discussing stock market investments, a company's performance is important. But so is the financial community's perception of that performance. To be sure, a good product or service, coupled with sound manage¬ment, remains important but is no longer enough. How stock analysts view a company's performance has become equally important. A major task of a mining company's investor relations officer, then, is to build and maintain a positive perception of the company to mining analysts throughout the world. That's a tough assignment in any market. The subject here, though, is gold. And, with its weakened price, gold companies must work harder to convince analysts their company is still a good investment. The analyst, on the other hand, must see through the corporate hype and decide whether it's worth recommending to clients as an investment. No simple task, either. Annual reports, 10-K forms, and quarterly reports only tell part of the mining company's story. Site visits, complete with discussions (sometimes interrogations) with a mine's principals, oftentimes tell an analyst more about a company's investment potential than the annual or quarterly report. So it was that three of the nation's major gold companies arranged a three-day tour of their gold operations in Nevada for a group of 22 analysts and a pair of mining industry scribes. The analysts represented investment houses the US, Canada, and England. The host companies and mines visited included FMC Gold's Paradise Peak mine, Amax Gold's Sleeper and Wind Mountain mines, and Battle Mountain Gold's Surprise and Fortitude mines.

Jan 1, 1989

By Taneomi Harada

Mine drainage has high acidity and sometimes contains more than the allowable concentration of ionized iron. In such a case, mine drainage is neutralized with calcium carbonate and calcium hydroxide to separate precipitates, such as the iron hydroxide and gypsum generated. Currently, most of these precipitates are not utilized and are accumulated in tailing dams. As a result, the service life of the tailing dams is reduced. This becomes a matter of concern, since securing sites for such dams is difficult. A most effective means of solving this problem would be to promote utilization of these neutralized precipitates. This paper reports on the results of studies on neutralized precipitates produced at the old Matsuo Mine (Iwate Prefecture), which has the largest neutralization treatment facility in Japan. As a result of the studies, the following was proposed regarding application of neutralized precipitates. Utilization as ferrite: Mix ferrous hydroxide and ferric hydroxide in water to synthesize magnetite-like ferrite, to be used in the manufacture of magnetic markers for a mobility support system for blind pedestrians, or in producing magnetic fluids for sink-and-float separation of nonmagnetic metals and nonmetals. Utilization as hematite: Bake ferric hydroxide to produce hematite, thereby extracting metallic iron for paint pigment as well as for the manufacture of ironware by local industry. Production of aluminum sulfate: Precipitate aluminum ions from water and add sulfuric acid to produce aluminum sulfate.

Jan 1, 1995

By J. Brendan Mclaughlin, Casimir J. Koshinski, Michael V. Rose, Wolfgang Baum

Mercury contamination is a worldwide problem in the mining, smelting, and refining of gold, silver, and copper. In these areas, mercury may be found as a naturally-occurring material in ores and concentrates, and/or in secondary feedstocks such as leach residues, pyrometallurgical treatment residues, refinery by­products, electrowinning electrodes, autoclave discharge solids, and waste water and acid plant sludges. The United States Environmental Protection Agency (EPA) has designated mercury one of the most harmful heavy metal contaminant in the environment and has implemented regulations that prohibit land disposal of characteristically hazardous wastes containing greater than 0.20 mg/1 TCLP mercury without prior treatment, thus increasing the cost of managing these materials. The presence of mercury in mine, smelter, and refinery by­products and wastes severely decreases, and in some cases eliminates, the ability to recover residual metal values from the contaminated material. The lost revenue associated with this disposal, combined with the increased direct cost of waste treatment, and/or disposal and protecting workers and the environment, can adversely affect overall profitability. The safe, efficient, and economical removal of mercury from gold, silver, and copper mining by-products requires a treatment process that is capable of liberating the mercury from the wide variety of compounds and matrices in which it may be contained, reducing the mercury content in the matrix to desired levels, and recovering the mercury in pure saleable form, without producing any secondary solid, liquid, or gaseous wastes. This paper reviews results from commercial operations and pilot scale tests using a thermal process owned and operated by Mercury Recovery Services, Inc. (MRS) to remove and recover mercury from copper acid plant blowdown sludge, Merrill­Crowe precipitate from gold/silver mining operations, and Cottrell and salt slag dusts from a precious metals refinery.

Jan 1, 1997

By Ronald I. Fuller

Core Laboratories, a division of Western Atlas International, maintains laboratories in all energy-producing areas of the United States, as well as in many foreign countries. Central to laboratory operations has been the incorporation of computers and computer software. Core has developed a mu1tiuser Laboratory Information Management System (LIMS) , which is currently installed in numerous company sites in the U.S., and is now undergoing installation in Canada. In addition, Core has provided custom soft ware to contract laboratories which Core operates on behalf of mining firms. The software development was done under the direction of the author in Denver, Colorado, and Casper, Wyoming. The intent of this paper is to pass some of the practical experience gained by our efforts on to those who wish to utilize computers more fully in the laboratory setting. The product of analytical laboratories is numbers. Nothing else comes from our work. We deal in information about samples. It is then reasonable to assume that the computer would be central to a laboratory operation. The hard part is to initially define what kind of computer the lab operation needs. The choices today can be very complex, and almost every hardware salesman is full of bad advice. Even the people in your own information services department may hold divided opinions. Since the advent of the personal computer, we have lived with a polarized data processing community. The PC boys consider their machines equal to any challenge, while the "save the mainframe" crowd view the PCs as limited toys that are only good for the things that clutter up a real computer. Management tends to lean toward whatever costs the least.

Jan 1, 1989

By James S. Redpath

"The ways of the world be many and most of the ways be tried, you follow in the footsteps of others till you come to the great divide". These words, written by Robert Service a long time ago, come to mind when I think of our original attitude upon entering into a contract with the International Nickel Company to sink the deepest shaft in the world outside of the Union of South Africa. This shaft was to be sunk to a depth of 7,137 feet from surface, and while it was recognized by all concerned to be a somewhat unusual undertaking in our part of the world, the fact that quite a few shafts had already been sunk to this depth in South Africa probably gave us the feeling that we were following in the footsteps of others. In retrospect, because this shaft was being sunk under entirely different conditions than those existing in South Africa, we were in fact venturing into an entirely new area of endeavour without properly recognizing this fact. It has occurred to me that others considering a similar type of job could benefit from our experience, especially in an assessment of the risks involved and how they compare to those encountered in an ordinary shaft. For comparison purposes, I would define an ordinary shaft as being sunk to a depth of 5,000 ft or less, and a deep shaft as one being sunk to a depth of between 5,000 ft and 8,000 ft. The sinking of the Creighton No. 9 Shaft has been de-

Jan 1, 1997

By M. R. Stokes, A. J. Ross

As a result of higher levels of production and greater depths the underground mining industry in the UK is encountering hotter climates in some workplaces. It is widely known that high heat and humidity in an underground workplace will result in reduced performance and may also seriously impair the health and safety of the workforce. It is therefore of paramount importance that the underground environment can be effectively predicted in order that sound decisions can be made to reduce the effect of climate on working personnel. Over the years numerous computer programs have been developed to predict the climate in underground mines. One such important program, developed by McPherson, is CLlMSlM TM which is a prediction model of heat and mass transfer along a single roadway. This paper describes the development of a computer model, called DRIVE, to predict the climate in single entry drivages. This program incorporates the theory established by McPherson for the development of CLlMSlM TM. This involves the algorithm for unsteady state heat transfer. Throughout the development of DRIVE underground measurements have been taken to correlate the program. DRIVE will predict the changes in psychrometric and thermo- dynamic conditions along the drivage depending on a number of parameters. Firstly, the type of auxiliary ventilation system employed such as forcing, exhausting, overlap. Secondly, the addition of heat and moisture due to autocompression, machinery, strata, fissure water, oxidation, broken rock, fallen rock, refrigeration equipment, lighting, personnel, service water. Thirdly, due to the velocity of the air.

Jan 1, 1997