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By Drupad B. Desai, James G. Gallanes

A key component of the Inland Feeder Project is the Riverside Badlands Tunnel, a7.9-mile stretch subjected to high internal and external hydraulic pressures passing beneath highly eroded hills in a semi rural environment. The tunnel presented significant design and management challenges to the project team. This paper describes the formula for project success used to manage the design of this complex pressure tunnel, from team member selection to the completion of all contract documents, on schedule and below budget. The project team dealt with sensitive regional and local community issues and won the trust of the community. The team included participation by senior management and recognized experts from inception to finish. The team worked diligently to build quality into design and adopted a claims avoidance approach to management and preparation of documents.

Jan 1, 1997

By Bobby J. Timmons

Luck; blind, beginner's, fisherman's, or whatever type, plays an important role in romance, racing, football, gambling, and mineral exploration. However, for each of these; education, training, technique, and experience are necessary for a long, continuous, successful relationship. Success, no matter how obtained, is easier to defend than almost success, regardless of the education or the degree of refinement of the seeker. Similarly, investment dollars are more readily available to a successful, uneducated and unscientific practitioner than to his beginning or unlucky professional counterpart.

Jan 1, 1983

By J. G. Dunn, A. S. Ibrado, D. J. Hollbach

Gold production is one the most important mineral process­ing industries in Western Australia. The gold is usually found in either weathered oxidised zones, or associated with sulfides. In the latter case, oxidation is achieved by some form of chemical processing, such as roasting or more recently bacterial leaching. In all cases, gold is dissolved out of the oxidised matrix by cyanide solution. Pyrrhotite is an iron sulfide generally represented by the formula Fe1_,S where O x 0.125. Three different structural forms ofpyrrhotite are known to occur naturally, stoichiometric FeS (troilite), hexagonal pyrrhotite Fe1_xS and monoclinic pyrrhotite Fe7S8 [I]. Substitution of iron atoms within the pyrrhotite structure by other ions of similar atomic radius such as nickel, copper, cobalt and manganese is also possible [2], and often observed in natural pyrrhotite samples. Pyrrhotite is abundant in Western Australian sulfide mineral deposits which are commonly associated with gold bearing ores. It is generally believed that pyrrhotite has a detrimental effect on gold recovery from such ores, as it is commonly claimed to decompose in alkaline, aerated cyanide solutions to form iron cyanide complexes, thus consuming free cyanide, and to form sulfur/oxygen containing species such as sulfate, through oxidation of sulfur in pyrrhotite, which thus consumes oxygen. From information gleaned from the literature, claims about the high reactivity of pyrrhotite in cyanide appear to be based on early cyanidation studies performed on gold ore samples which have been poorly characterised, and contained impurities such as pyrite, arsenopyrite and chalcopyrite, which may have also contributed to the levels of species observed in solution [3-5]. In addition, the investigations do not take into account that iron atoms in the pyrrhotite structure may have been partially substituted by other atoms that influence the solubility of pyrrhotite in cyanide solution.

Jan 1, 1995

By Qun Wang, Elena A. Alonso, Janusz S. Laskowski

Primary normal long-chain amines are insoluble in saturated brine. Their colloidal solubility (dispersion) in concentrated electrolyte solutions is strongly affected by the presence of surfactants (frothers). This paper shows that a better usage of alcohol type surfactants, which are commonly used in potash ore flotation as frothers, can significantly improve the flotation of both coarse and fine sylvite particles. A new process of potash ore flotation is developed, which includes premixing an effective frother with an aqueous solution of amine or emulsion of extender oil containing amine. With such a combination of flotation reagents, KC1 particles up to 5 mm in size float very well in the short flotation column, and particles up to 2 mm float in a mechanical cell; when used to treat fine fraction-containing sample, this method may as well provide an improved concentrate grade.

Jan 1, 1995

By Robert A. Haney

During the last ten years, longwall mining systems have undergone many changes. Panel widths and lengths have increased. Longwall faces have become more automated. Average production from individual longwall panels has increased from 1,000 to 3,600 tons per shift. To control the dust generation resulting from the higher production, longwall dust control systems have integrated various dust control techniques. Systems designed to control dust generated at the crusher/stageloader, shearer, and supports are common to most longwall faces. A survey was made of the dust controls that are currently in place on all the longwalls in the U.S. This survey addressed the types of controls used to reduce dust generated at the crusher/stageloader, shearer and roof support movement. Additionally, information on face ventilation rates, cutting cycle and level of automation was obtained. The purpose of this paper is to review the dust control practices that have been implemented throughout the United States and to identify those controls that are being used on high production longwall faces. Additionally, a model is used to demonstrate how ventilation and automation affect occupational exposure. Automation of roof support movement can offer some of the greatest reductions in occupational dust exposures. While technically feasible, its full benefit has not been fully realized by the industry. Until technology to fully automate longwall mining systems becomes more reliable, future dust control systems must rely on increased ventilation, application of headgate dust collectors, improved shearer dust controls and improved shield dust suppression systems.

Jan 1, 1995

By M. B. Haggerty, Joe Welna

The Minnesota Department of Transportation is constructing a stormwater storage facility (SSF) along Interstate 35W (I35W) south of downtown Minneapolis, MN. The project will provide storm surge capacity reducing the frequency with which major precipitation events result in flooding of I35W. The design consists of six, 42-foot diameter, 90-foot deep, adjacent underground shafts providing 14.7-acre feet of storage. Construction challenges include high groundwater with variable glacial outwash deposits. Constructability and ground variability were managed using construction manager general contractor (CMGC) project delivery. CMGC provides an environment for collaboration and innovation starting in the design phase and carrying through construction. This paper provides an overview of key efficiencies and collaboration examples implemented on the I35WSSF project which were aided by CMGC delivery.

Jun 13, 2023

By Gary L. Simmons

Many large (refractory) sulfide gold resources exist in Nevada and other parts of the world that are not amenable to conventional flotation concentration using air as the flotation gas medium. Over the past five years Santa Fe Pacific Gold Corporation (SFPG) has investigated flotation process options to economically treat refractory ores and resources of this type at its Lone Tree and Twin Creeks mines. Conventional flotation technology applied to the original high-grade gold resources at Lone Tree and Twin Creeks was initially unsuccessful. Review and analysis of auriferous (gold-bearing) iron sulfide mineralogical characteristics and flotation ..:hemistry provided a fundamental understanding that led to the development of a new flotation process that SFPG refers to as N2 TEC. This paper discusses the development of this technology and compares N TEC results with conventional flotation practice.

Jan 1, 1997

By Kadri Dagdelen, M. Waqar Asad

Cement production involves the processing of raw materials that contain - Si02, A1203, Fe203, CaO, MgO, LOI (loss of ignition), S03, K20, Na2O, Ti02, P2055 and Cl- to produce the synthetic mineral mixture called "clinker". The use of other additives - sandstone, flyash, iron ore, and clay - is also mandatory in order to achieve the optimum blending requirements of cement. However, the use of these additives needs to be minimized due to their significantly higher costs ($/Ton). This paper presents a mixed integer programming (MIP)-based optimum quarry scheduling algorithm, which is used to generate quarry plans, satisfying geometric and production capacity constraints while providing minimum cost/optimum blend of raw materials mix to a cement plant. The benefits of this new methodology are demonstrated on a case study.

Jan 1, 2002

By Robert W. Miller, Rhoda S. Kriesel

INTRODUCTION With each passing year, the general public becomes increasingly aware of the potential hazards associated with many products and services previously considered unharmful. This new consciousness is especially evident in the workplace, both as the result of advances in scientific understanding and the influx of concerned, responsible professionals into the labor movement. For example, data produced by epidemiologists doing retrospective mortality studies which related mortality to toxic substance exposures has often been the prime motivating factor behind reductions in exposure standards. This certainly has been the historical case with many radiation exposure standards, including the limitations set for "Working Level" exposure. The concept of "Working Level" was introduced in PHS Publication No. 494 as a result of both the difficulty in relating radiation units to biological effects and the complexity of interaction of radon daughters with the physical environment. WORKING LEVEL One working level is defined as any combination of radon daughters in one liter of air that will alternately release 1.7 x 105 MEV of alpha energy during decay of 210pb (RaD). Its usefulness is that working level can be readily measured in both the field and the laboratory. Because of this, existing occupational exposure standards for radon daughters in both the U. S. and other countries use working level as their basis. In the U. S., the last twenty years has witnessed a significant reduction in radiation exposure standards from 120 working level months to 4 working level months per year. New international standards are being proposed that would be only slightly higher than these current U. S. standards. POTENTIAL EXPOSURES TO RADON DAUGHTERS The universal use of nuclear power, along with the transfer of nuclear technology to developing nations, has significantly increased the demand for fuels. As a result, uranium mining operations have expanded and increased numbers of miners are regularly exposed to radon daughters. In addition to potential exposures in uranium mines, other deep mines such as tin, gold, platinum and tungsten, also have potential exposures due to the distribution of uranium and its accompanying radium throughout much of the earth's crust. The energy crisis has also prompted interest in general population exposure to radon daughters in buildings. Many homeowners, using additional insulation and caulking to seal cracks and conserve energy, have reduced indoor ventilation to the point where working level exposure could become significant, especially in homes with unventilated crawl spaces. In fact, several serious exposure situations have occurred where mine tailings were used for building materials. MEASUREMENT TECHNIQUES Historically, rapid and convenient measurement techniques have been actively sought to improve the ability of ventilation engineers to limit mining exposures through ventilation control. A number of measurement techniques have been developed, including the Kusnetz method (further elaborated by Shalaynev) and techniques developed by Rolle and Tsivoglou. All, however, suffer from similar handicaps that prevent their usefulness in the mining environment. Their main limitation, in terms of minimizing employee exposure, is the elapsed time from the start of sampling until the results can be calculated. It is usually 40 to 90 minutes. This time delay presents both serious economic limitations as well as the potential for exposing workers to high radon daughter concentrations until calculations are completed and corrections made. Further reducing the utility of the Kusnetz and Tsivoglou techniques is the need for tedious calculations that increase the possibility of human error along with the need for cumbersome sampling equipment that is not ideally suited to the mining environment. INSTANT WORKING LEVEL METER To alleviate these problems, the idea of an Instant Working Level Meter was conceived by several groups. Several such instruments were proposed, built, and tested with disappointing results. Although the concepts behind them were sound, the instruments simply failed to measure working level without excessive distortion. In addition, their cost was relatively high, gamma background presented a problem, and sophisticated computations were necessary to determine working level. In short, these systems lacked the design engineering that would make them suitable for the demands of a mining environment.

Jan 1, 1981

By John R. Duble

Through 1980, demand for cement in the Pacific Basin countries still seemed to exceed output. Availability of cement in the industrialized and developing countries of East Asia, Southeast Asia, and Australasia for the 1975 - 1980 period are discussed in this report. Quantitative data includes production, imports, exports, and apparent consumption. An account of new cement plants and plant extensions is provided. Countries and areas covered include: East Asia---Japan, South Korea, North Korea, Taiwan, China, Hong Kong, Philippines; South east Asia---Thailand, Vietnam, Singapore, Malaysia, Indonesia; Oceania (Australasia)---Australia, New Zealand, New Caledonia, Fiji.

Jan 1, 1982

By K. Lagnese, C. Robinson, S. Muddasani

"Mine water generated from underground coal mining operations contains both dissolved and particulate solids. Dissolved solids primarily consist of sodium, calcium, magnesium, potassium, chlorides and sulfates. When discharged to a receiving stream without treatment, these constituents create a potentially toxic environment for aquatic life. A case study is presented to discuss how a centralized treatment plant treats mine water from six locations to meet discharge limitations for chlorides. Located in West Virginia, this facility consistently achieves less than the NPDES permit limitation of 218 mg/L chlorides in the discharge while generating almost zero liquid waste. The dissolved solids concentration in the influent ranges between 5,000 and 10,000 mg/L, with chloride concentrations of 1,000 to 2,000 mg/L and sulfate concentrations of 2,000 to 6,000 mg/L. The mine water is treated using advanced treatment technology to produce clean water for discharge or reuse. The treatment process comprises aeration, softening, filtration, reverse osmosis, RO reject softening, evaporation, crystallization, final effluent remineralization and sludge dewatering. The solid waste generated in the treatment process is landfilled on site. The leachate is sent back to the facility’s thermal treatment process. Because no liquid waste leaves the property, this plant is termed a “Zero Liquid Waste” (ZLW) facility. INTRODUCTION The advanced water treatment system was built to meet a new 218 mg/l regulatory limitation imposed by the West Virginia Department of Environmental Protection for chlorides discharged to surface waters. The system is designed to treat a maximum flow of approximately 5 million gallons per day (795 m3/h) of mine water. The treatment process utilizes reverse osmosis (RO) membrane treatment to achieve the effluent criteria, and evaporation and crystallization technology to manage the RO concentrate from the water treatment process. As a result, the system produces clean water for discharge while generating zero liquid waste. The effluent water can be used for industrial purposes or discharged to a receiving stream. A Water Impact Index (WIIx) study indicated that discharge of this high-quality water into the Monongahela River watershed may improve the water quality for downstream water users. The waste produced in the treatment process, including softening sludge and salt, is disposed of in an on-site landfill."

Jan 1, 2015

By Roger S. Dewey

1.1. INTRODUCTION Despite indications of a general economic recovery in the U.S. during the mid-19801s, mine operators have not generally shared in the benefits of these reported better times. Budgets have not rebounded, borrowing is tougher, parent companies' pockets are not as deep as in previous years, and margins are not any better -- if there is any left over at all. Managing capital equipment budgets is always a challenge, and the last five years of stretched equipment lives make these decisions more tenuous. Delays and avoidance of replacements due to tough times inevitably makes those decisions increasingly difficult and usually more expensive The purposes of this paper are to present. a brief refresher outline of the fundamentals of equipment replacement analysis, to suggest a number of papers where analysis methods are explained in greater detail. and to recommend the use of a widespread microcomputer software capability (1-2-3) as the easiest path to a much-needed solution for a very difficult, and usually under-supported management decision problem 2. REPLACEMENT DECISION POLICY Investments in equipment replacements must compete for capital with all other investment alternatives. Capital for replacements of ten represents a greater commitment than do the new projects which a company might handle in a given year. But. sadly, formal policies for standardized analysis of replacements rarely exist, even in major companies. Yet this policy can be very significant in determining the competitiveness of a firm. Whereas many replacement decisions are based on cost minimization, economists and financial analysts agree that wealth maximization or return on investment is the superior criterion. Though the difference may seem slight, agreement on a firm's financial objective is vital. Replacement policy should be straight- forward. have a logical basis, and a proper level of sophistication. There are several reasons to develop a policy for replacement decision-making: [I] 1 - equipment's optimal economic life is nearly always shorter than its physical life; 2 - mine life often exceeds equipment life, so management must face these decisions routinly 3 - replacement capital costs, on an undiscounted basis, can run 25 to 75% of original capital 4 - technological changes may result in a newer machine or system which can operate more efficiently, more safely. or less expensively 5 - estimates should be made consistently in the fundamental areas of life expectancy, availability, utilization. price escalation, taxes 6 - long-term and short-term budgeting without decent data and analytical capability is nearly impossible, or at least ineffective Policy development assumptions which must be considered include: the planning horizon, cost patterns, interest rates, availability of capital, replacement vs. expansion, technology advances.

Jan 1, 1987

By Karl E. Elers

The term "potash" denotes a family of minerals and compounds of potassium, containing greatly varying percentages of that element. In commercial usage, most of the potash products are used in agriculture, where they are used to furnish potassium, one of the three basic elements for plant growth; the other two being nitrogen and phosphorus. Potassium's contribution to plant life is principally as a stalk strengthener, and if soils can no longer supply this basic element, then crop failure is inevitable without nutrition supplied from fertilization. While agriculture uses some 95 per cent of the potash produced, other industries require highly refined potash, for the manufacture of soaps, dyes, pharmaceuticals, synthetic rubber, insecticides, photographic film, and other products. Until the mid-nineteenth century, world agriculture had three options related to the potash content of soils: 1) crop rotation and pasturing to attempt to minimize the loss of potash in harvesting, 2) abandoning depleted and exhausted soils (part of the reason for the vast migration of populations in Europe and Asia), and 3) burning forests for the use of the ashes, and concentrating the nutritional value by boiling the ashes in large kettles, for "pot - ash". With the discovery in the mid 1800's and exploitation of potash from underground deposits in Germany, the beginning of the modern potash industry was established, but American potash requirements remained substantially dependent on German production until the 1920's, when oil drilling in the Permian Basin of New Mexico

Jan 1, 1972

By E. Lovera

Social attention to environmental aspects, steadily increasing in European Countries, has been leading to a stricter regulation of many productive activities. Among them, mining and quarrying sectors have been often censured for their potential and real impacts on land and environment. Referring to dimension stone exploitation (also the terms ornamental stone or natural stone are here used as synonymous), quarries are often concentrated in extractive basins, where the resource is localized with suitable quality and quantity: this fact has sometimes raised critical environmental situations. Nevertheless, dimension stone quarrying represents in Europe a traditional and important economical activity, source of wealth and employment. Moreover, many natural stones take on a ?cultural? value and may be considered as ?classic?, as they have been exploited since antiquity and are element of the architectural heritage of many Countries. The sector relevance demands the research of a sustainable balance between social-economical needs and environmental protection. Actually, very restrictive environmental protection policies have led to severe limitations to quarrying activity, but the results do not seem to be completely positive in terms of sustainability: on the one hand, closing-down stone quarrying activities imposes a shrinkage in local, social and economical development; on the other, quarrying activity is pushed towards developing Countries, environmentally un-protected, simply moving and putting off to next future the problem. The challenge of the sustainable development of quarrying sector ? recently explored in the European Commission?s communication ?Promoting sustainable development in the EU non energy extractive industry? (COM-2000-265) ? should be achieved through a positive link between theoretical statements and practical effects: sustainability indicators may be an effective instrument to assess and monitor the environmental performance of the industry. The paper refers to the development of specific ecological criteria and indicators, which can be useful to measure and predict the eco-efficiency of a dimension stone quarry, finally pointing out where improvement efforts have to be focused.

Jan 1, 2003

By A. Cecala, J. Noll, J. Hummer

"NIOSH has observed that many control rooms and operator compartments in the US mining industry do not have filtration systems capable of maintaining low dust concentrations in these areas. In this study at a mineral processing plant, to reduce respirable dust concentrations in a control room which had no cleaning system for intake air, a filtration/pressurization system originally designed for enclosed cabs was modified and installed. Eighty-seven percent of submicron particles were reduced by the system at static conditions, meaning that greater than eighty-seven percent of respirable dust particles should be reduced. The particle size distribution for respirable dust particles are greater than for submicron particles, and filtration systems usually are more efficient in capturing the larger particles. A positive pressure near 0.02 inches of water gauge was produced which is an important component for an effective system and minimizes particles (e.g. dust) from entering into the room. The intake airflow was around 118 cfm, which is greater than the airflow suggested by ASHRAE for acceptable indoor air quality. INTRODUCTION Chronic overexposure to respirable silica dust (particle diameter < 10 microns) leads to a progressive lung disease known as silicosis. Workers who develop silicosis have an increased incidence of lung cancer and pulmonary disorders. In June 1997, the International Agency for Research on Cancer (1) found sufficient evidence to declare that inhaled crystalline silica in the form of quartz and cristobalite is carcinogenic. Mining is one of the leading industries for occupational exposure to silica dust (2-7). Control rooms located in dusty areas in some mines are of particular concern (8). Many mineral processing operations utilize operator’s compartments and/or control rooms to house workers who are performing particular job functions. Most industrial processing mills have rooms where a worker looks out over the facility and has direct control over the product flow throughout the entire building. In addition, primary crusher operators are often located in a compartment from which they are able to view the primary crushing function. Their job is to control when trucks dump into the primary jaw crusher and the rate of feed of the ore from the hopper into the crusher. Many of these control rooms and operator booths do not have filtration systems capable of cleaning air entering the control room or booth, which can result in elevated concentrations of dust in the room or booth. To reduce the dust concentrations in these rooms, it would make sense to clean the entering air with filtration/pressurization units similar to those proven to provide a clean environment in enclosed cabs."

Jan 1, 2016

By J. P. Mogan

As diesel exhaust contains a mixture of several materials of varying degrees of toxicity which interact to a currently undefined extent in their effects on health, the prescription of a quantity of ventilating air to dilute the exhaust to a safe level is necessarily, to some extent, arbitrary. Some jurisdictions rely on the application of a safety factor to a single "governing" component (usually nitric oxide for most modern diesel engines). Others specify that the total of the "adjusted" concentrations (actual concentration divided by maximum permissible concentration) not exceed "one" for related constituents (irritant gases for example). Neither of these approaches, however, takes account of the interaction of the gaseous constituents with diesel soot (although many studies verify such interactions), nor do they provide any economic incentive for reducing pollutants which are not included in the criteria for ventilation. Because of these factors, the Canadian Department of Energy, Mines and Resources awarded a contract for a study of the current literature bearing on the "Health Implications of Exposure of Underground Mine Workers to Diesel Exhaust Emissions" (1). One goal of this study was the formulation of a new ventilation criterion. The contractors, Ian W. French and Associates, studied more than 1500 literature citations which they interpreted in a 350 page report and summarized in a companion 1600 page annotated bibliography. In the recommendations section of the report, they defined a new &apos;health effects index&apos; or ventilation criterion "V" as follows: [ ] The contractors consider that a "V" between 3.0 and 4.0 poses a moderate threat to health which could be alleviated by the use of protective equipment such-as filter helmets. If V exceeds 4.0, an increase in ventilation quantity to reduce the pollutant levels is indicated. In the case of mines with a quartz content in excess of 20% in the ore, the contractor recommends that a term. [Quartz]/ [Threshold Limit Value Quartz] be added to the equation, and [2.0 = ?v? = 30] be the range justifying protective equipment, with added ventilation if "v" exceeds 3. A degree of pragmatism was inherent in the development of the equation, as the contractors recognized that the components of the index, if it is to be useful in the near term, should be within current routine underground environmental assay capability.

Jan 1, 1980

By Arthur C. Pincomb, Alan R. Shapiro

A public awareness of and commitment to abate pollution of water, air, and soil continues to stimulate demand for industrial minerals and rocks capable of neutralizing strong and weak acids. The role of acid neutralizing agents is 1) to treat acidified water and soil until the desired pH is attained and 2) to remove acid-forming compounds from industrial processes to mitigate the formation of acidic discharges. Environmental applications for these agents include: acid rain mitigation, neutralization and prevention of acidic industrial process discharges, and treatment of acid mine drainage and coal refuse. Desulfurization of industrial flue gases involves removal of sulfate compounds capable of combining with hydrogen to form acids. Details of flue gas desulfurization are covered in the previous chapter on Flue Gas Desulfurization. Ideally, the neutralization of acids results in an upward adjustment of effluent pH 7, or neutrality. The final pH value for many acid treated wastes, especially industrial discharge streams, is commonly over neutralized to pH 8.5 to 9.5. The Clean Water Act sets the upper discharge limit at pH 9. ACID NEUTRALIZATION REAGENTS Acid neutralization is accomplished by adding alkali metal and alkaline earth metal compounds to acidic water or soil until the desired pH is attained. The commonly used alkali ions are calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K). Sodium hydroxide, high calcium and dolomitic hydrate, high calcium and dolomitic lime (quicklime), high calcium and dolomitic limestone, soda ash, and magnesium oxide are the compounds most commonly applied to raise the pH of acidic waters or soils. Limestone and dolomitic limestone, which are calcium and magnesium carbonates, and their equivalent oxides and hydrates formed by calcination, are the industrial materials most commonly used in the manufacture of reagents for acid neutralization. Approximately 327 kt of high calcium and dolomitic lime were consumed for acid neutralization purposes in 1988. Magnesite and brucite are industrial minerals that compete with dolomitic limestone for the magnesium-oxide market. Production of caustic calcined magnesia for neutralization purposes exceeded 6 kt in 1990. Soda ash is an industrial mineral gaining increased acceptance in the neutralization of acid waste discharges. Approximately 182 kt of soda ash were consumed in 1990 for acid waste treatment or acid prevention by flue gas desulfurization. Other mineral products either consumed in minor quantities or receiving attention as future neutralizing agents include zeolite and hectorite. In some cases, waste products have been found to be suitable and cost effective for neutralization of acids. Common wastes gaining acceptance include basic slag, phosphate mining refuse, cement kiln dust, fly ash, and mine tailings.

Jan 1, 1994

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

It is imperative that the hydrogeologic frame- work and the ground water flow systems of a Potential mine area be investigated prior to initiation of mining. Such investigations are necessary so that potential mine water inflow problems can be anticipated and controlled. Obvious difficulties can arise if large inflows of ground water occur in underground workings. Costs of water removal and disposal, if not foreseen and included in economic planning, can severely limit or eliminate profit from a mining operation. Safety problems associated with large inflows are an additional potential problem. The inflow of water into a mine necessarily alters the associated ground water system. The inflow also may impact nearby surface water regimes, depending upon the interaction of the surface water and ground water systems. The inflow of water into a mine inevitably causes a decline in the ground water levels in the vicinity of the mine. This decline may be restricted to a small area or it may extend a considerable distance, depending upon the hydrogeologic properties of the associated hydrostratigraphic units. A decrease in surface flow will result if the area of ground water level decline intersects a stream or spring that is hydraulically connected to the ground water system. Mine inflow problems historically have been evaluated after-the-fact. Premining hydrologic investigations only recently have been initiated. Brown&apos;s (1977)* report on anticipated hydrologic impacts of oil shale mining in the Piceance Basin of Colorado is an example of premining hydrologic planning. Observed difficulties inherent in designing a data collection network and then utilizing the data to predict mine inflow have led us to the preparation of this manuscript. This manuscript reflects a two-phase effort. The first phase describes and develops analytical and numerical techniques for mine inflow prediction. Emphasis in this section is placed on the selection and application of data collection techniques and data analysis procedures. The second phase applies the prediction technique(s) developed during phase 1 to two existing mines. The objective of phase 1 efforts is to evaluate the hydrologic variables associated with surface water systems and ground water systems that can affect the inflow of water into an underground mine. Subsequently these variables are incorporated into predictive techniques for estimating underground mine water inflow and its effect on associated ground water and surface water systems. The specific objectives of phases 1 and 2 are to: 1) Determine the hydrologic parameters required for predicting underground mine water in- flow and the potential effects of the inflow on surface and ground water systems. The hydrologic parameters represent both premining and past initiation conditions. 2) Outline methods for obtaining the necessary input data for the predictive techniques in pre- mining and post initiation periods. 3) Present existing numerical techniques for predicting underground mine water inflow including assumptions Ad required input. 4) Evaluate existing numerical techniques previously tabulated based on their applicability to mine water inflow prediction. 5) Attempt to develop analytical techniques for predicting underground mine water inflow. 6) Develop, through modification of existing models, a general mathematical model as a numerical technique for predicting underground mine water inflow and the resultant effects on surface and ground water systems. 7) Apply the predictive techniques to two existing mines selected for this purpose. 8) Compare the predicted inflow rates to measured inflow rates at both mines. 9) Compare predicted impact on district hydrology to observed impacts where possible. 10) Evaluate the predictive technique.

Jan 1, 1986

By Henry N. McCarl

The New England States form the most northeastern portion of the continental United States and include Connecticut, Rhode island, Massachusetts, Vermont, New Hampshire, and Maine. These states have an aggregate population of over 10.5 million people, and an average annual population rate increase of about 1.3%. A great deal of new construction is required each year to meet the increasing demand for new homes, roads, offices, factories, and warehouses. Yet, prices of construction materials such as blocks and concrete are generally higher in New England than in other well populated areas of the United States. This is an indication of local demand being somewhat greater than supply, an atmosphere conducive to new developments in the production of construction materials. One such field of development is the rapidly growing Lightweight Aggregate Industry. Recent construction in Boston has used a great deal of lightweight aggregate. New structures using lightweight aggregate in lightweight concrete include the following: M.I.T.&apos;s 20-story Earth Science Center and 17-story Married Students Housing Project Prudential Life Insurance Center, West End Redevelopment Project at Charles River Park, Hotel Americana, and the British-owned 33-story office building at 50 Pearl Street.

Jan 1, 1964

By Deepak Malhotra

Is operator training necessary for optimization of flotation plants? The answer is obvious-Yes. The author suggests a three-phase program for operators when new plants are built or new crews are hired in existing operations. Case examples are discussed to illustrate the benefits of operator training.

Jan 1, 1999