Search Documents

By J. E. Warren, J. H. Hartsock

An asymptotic solution to the equation that describes the flow of a slightly compressible fluid in an infinite porous medium has been used to estimate the interaction between two adjacent wells producing from a common reservoir. A direct method for approximating the interference time defined by Stevens and Thodosl has been suggested. An alternative definition for the time of interference, based on the minimum pressure change in the interference region, has been proposed; also, a direct method of determination has been prescribed. Examples have been employed to illustrate the use of both methods.

By Joseph L. Petrillo

In July 1997, Kvaerner Environmental signed a unique contract with Echo Bay Alaska called the Transfer Risk and Accelerate Closure (TRAC). The contract called for Kvaerner to assume the responsibilities and obligations associated with closeout of the Alaska-Juneau (A-J) Mine. Kvaerner is an international engineering and construction company with global interdisciplinary experience in the mining industry and environmental remediation. Echo Bay’s requirements called for Kvaerner to: •Provide a fixed price for closure with no change orders. •Negotiate, prepare and implement a final closeout plan as outlined by Echo Bay. •Complete a closure program that exceeded current regulatory requirements. •Improve, expand and maintain a proactive public and community relations program. •Hire Echo Bay employees where possible. •Provide adequate performance guarantees and judicial relief of environmental claims.

Jan 1, 1999

By James Dunn

“The strongest argument of the detractor (of mining)is that the fields are devastated by mining operations ...They argue that the woods and groves are cut down, for there is need of an endless amount of wood for timbers, machines and the smelting of metals. And when the woods and groves are felled, then are exterminated the beasts and birds, very many of which furnish a pleasant and agreeable food for man. Further, when the ores are washed, the water which has been used poisons the brooks and streams, and either destroys the fish or drives them away.” Georgius Agricola, 1556, De Re Metallica, translated by Hoover, 1950. Technical problems associated with the cleanup of historic mines are not new. Nor are they unique to the mining industry or the governmental agencies addressing them. Both face the same issues and challenges of defining the problems, evaluating remediation options and finding the most economic and effective solutions.

Jan 1, 1999

By R. Larry Grayson, Ahmet Unal

Use of radio frequency identification (RFID) technology to solve informational needs in isolated and restricted underground mining environments will be reviewed, giving specifications of some past and currently available systems. The advantages and disadvantages of using various frequencies, system configurations, and specific components, including their construction standards and capability, will be discussed. The remaining challenges to more widespread use of RFID systems for personnel and vehicle tracking will be identified, and recommendations concerning operating environment capabilities will be detailed. Finally, the ultimate requirements for maintaining system integrity during and following a coal mine emergency will be discussed.

Feb 24, 1997

By Ch. Schroeder, F. Collin, R. Charlier, Y. J. Cui

The paper proposes two numerical models ot the mechanical behaviour of chalk. First, an elasto-plastic constitutive law reproduces the different plastic mechanisms of the chalk and the influence of pore fluids by introducing the concept of suction. Secondly, a model able to reproduce time dependence behaviour. Eventually, the paper gives a simulation of an academic reservoir during depletion and waterflooding phase. Der Artikel stellt zwei numerische Modelle des mechanischen Verhaltens der Kreide vor. Das erste ist ein elasto-plastisches Modell, das verschiedene plastische Mechanismen der Kreide und den Einfluss von Porenflüssigkeit, unter dem Begriff der Suktion, reproduziert. Das zweite Modell berücksichtigt darüberhinaus das zeitabhängige Verhalten. Schliesslich zeigt die Veröffentlichung eine Simulation einer theoretischen Lagerstätte während der Entleerung und der Wasserinjektion. L'article propose deux modèles numériques du comportement mécanique de la craie. Le premier est une loi élasto-plastique qui reproduit les différents mécanismes plastiques de la craie et l'influence du fluide interstitiel par l'introduction de la notion de succion. Le second est un modèle prenant en compte les effets différés. Enfin, l'article présente une simulation d'un réservoir académique durant les phases de déplétion et d'injection d'eau.

Jan 1, 2003

By William G. Schultz

Sylvite of Canada, a wholly owned subsidiary of Hudson Bay Mining and Smelting Co., operates an 8000 TPD potash mine and refinery located nine miles North East of Rocanville, Saskatchewan. Prior to Hudson Bay's entry in 1968 into potash mining and refining, it was one of the more traditional and conservative Canadian Mining Companies whose principal business had been for many years a successful copper-zinc mining and smelting operation located at Flin Flon, Manitoba. The potash reserves being mined by Sylvite were acquired through the acquisition of Francana Oil and Gas. This acquisition was at the time when several major potash mines were being developed or had recently been brought into production in the Province. These mines are owned by either very substantial Canadian Mining Companies or Multi-National Mining Companies with considerable potash mining experience. At that time, it became very apparent because of the new mines coming into production, potash mining and refining would quickly become a very competitive industry. Because of long term considerations, Hudson Bay decided to proceed with the development of its potash reserves, recognizing the Mine and Refinery would have to be the most advanced available in order to successfully operate. This report deals with the mining operation at Sylvite and the degree of success Sylvite has achieved.

Jan 1, 1972

By H. D. Outmans

A method has been developed for determining the relative water wet-tability (fraction of the surface wet by water) of porous media. This method involves the adsorption of methylene blue dye from an aqueous solution onto the solid surfaces of rock contacted by the injected dye solution. Experiments on Berea snndstone cores have shown that water-wet cores adsorb a large amount of dye from solution. In oil-wet cores, however, the injected aqueous dye solution is prevented from contacting the adsorptive surfuces by a film of oil and virtually no dye is adsorbed. This method was tested by experiments on mixtures of water-wet and oil-wet sand. Using the dye adsorption method, it was possible to determine quantitatively the fraction of water-wet and oil-wet sarzd in such mixtures. The dye adsorption test is readily applied to determinitrg the relative water wettability of fresh oilfield cores. The cores are not extracted before testing. Observed values of the wettability of field cores tested to date have varied from 100 to 6 per cent water wet. INTR OD UCTIO N Recent articles1 ' have emphasized the important role that wettability plays in almost all phases of reservoir rock behavior. It has been shown that wettability has a profound effect on the interstitial water saturation, residual oil saturation, capillary pressure, relative permeability, waterflood behavior, and resistivity index of oilfield cores. A quantitative investiga- tion of the effect of wettability on these core properties is severely handicapped by the lack of a simple technique for measuring the wettability of a porous medium. If such a technique were available, it would provide investigators with a means of gaining insight into the distribution of phases within a core. A number of qualitative methods of estimating wettability are known. These include contact angle measurements, flotation tests and studies of displacement pressure: imbibition7 and relative permeability data.' Using these tests, it is usually possible to classify a core as water-wet, oil-wet, or some intermediate degree of wettability. One recently proposed method involving measurement of nuclear magnetic relaxatione offers promise of determining quantitatively the fractional wettability of cores. The equipment is rather elaborate and necessary treatment of the cores before testing probably alters the natural wettability. This latter point also applies to most of the cited qualitative methods. This paper presents a new technique for determining water wettability of cores; it is based on measurements of the dye adsorption capacity of the core. This method has the advantage of requiring relatively simple equipment and involves minimum handling of the core before testing. It is important to distinguish between the various concepts of wettability referred to in the literature. The term "wetting" is defined by Bartell as that phenomenon which occurs when a solid and liquid phase come in contact in any manner so as to form a solid-liquid interface. A preferentially water-wet solid is defined by Jennings in terms of the advancing contact angle in the solid water-oil systems. Brown and Fatt regard fractional wettability as the fraction of the total surface area that is preferentially oil-wet or water-wet. However, none of these definitions adequately describes the type wettability measured by the dye test. This calls for the introduction of a new term, "relative water wettability", which we define as the fraction of the total surface area of a core contacted by injected water. DESCRIPTION OF METHOD The ability of a porous medium (especially the clays) to adsorb large quantities of surfactants, dyes, etc., is well known. It is reasonable to assume that a substance can be adsorbed from solution onto a solid surface only if the solution contacts the surface. In this connection Shapiro" has shown by experiments on silica gel that completely dry gel will adsorb methyl red dye from a benzene solution. On the other hand, if a film of water more than several molecules thick is present on the silica gel, the adsorption capacity of the gel for the dye is drastically reduced. Thus, a study of the dye adsorption capacity of cores should give some clue as to the fluid distribution on the surface of the core. TEST OF METHOD As a qualitative check on this theory, dye adsorption tests were run on similar Berea sandstone cores (Table 1, Cores 1-5). Cores saturated initially with water and flooded with 0.01 per cent aqueous methylene blue adsorbed 0.58 mg dye/gm of core. Similar cores saturated initially with water, driven to irreducible water with oil, and then flooded with the same dye solution also adsorbed 0.58 mg dye/gm of core. Another core, treated with a 5 per cent Dri-Film solution, dried and saturated with oil (Soltrol) adsorbed no dye when the dye solution was injected. These tests confirm

By James W. Weaver

The 2,120-foot long cable stayed Penobscot Narrows Bridge that carries US Route 1 over the Penobscot River between Verona Island and Prospect, Maine is supported on four foundation units, one below each pylon and one at each abutment. Due to varying subsurface conditions along the bridge alignment, the structure was designed to be supported on foundations consisting of high-capacity steel H-section piles (Verona Pylon), a mat bearing on a prepared bedrock surface (Prospect Pylon) and spread footings bearing on compacted rockfill (abutments). The 70-foot by 80-foot (plan area) Verona Pylon foundation was designed to be supported by 288, 430-kip design capacity steel H-section piles (HP14x117, 50 ksi steel) driven through up to 100 feet of dense glacial till deposits containing cobbles and boulders up to 3 feet in diameter. The piles were installed using a single-acting diesel hammer (Delmag D62-22) with a maximum rated energy of 165 kip-ft. Thirteen representative piles were selected for dynamic testing (ASTM D-4945) to verify pile capacity, hammer efficiency and pile stresses. Dynamic testing determined that four different pile driving criteria were needed across the site due to variation in the bedrock and soil resistance below the footing plan area. Approximately 4 percent of the production piles were damaged/rejected due to misalignment and/or damage as a result of encountering the cobbles and boulders embedded in the glacial till. The rejected piles were located randomly throughout the plan limits of the foundation mat. Subsequent structural analyses indicated that the foundation was capable of safely supporting the design loads without the need for installing replacement piles. Evaluation of dynamic testing results with signal matching and pile driving records provided valuable information on pile side and tip resistance. Evaluations were made regarding predicted versus actual pile lengths, pile bearing material, distribution of skin friction and end bearing capacities.

Jan 1, 2011

By P O. Koons, R J. Norris, S C. Cox

 The Southern Alps is an active oblique collisional zone which has a characteristic wedge-shaped geometry above a low-angle ductile shear zone. The Main Divide region is a relatively low strain zone above this ductile shear zone, and is _deforming principally along steeply dipping strike-slip faults. Extensional fractures are common at a high angle to the regional structural trend. These steeply dipping structures act as conduits for gold-bearing fluids from depth, and small mesothermal gold deposits have formed at several structural levels including the near-surface region. Gold has also been deposited in a meteoricmetamorphic fluid mixing zone near a conductive thermal anomaly on the western slopes of the mountains. These various gold deposits and their well-constrained structural and tectonic settings can be used as analogues for larger, deeper-eroded mesothermal gold deposits in the Mesozoic Otago Schist belt. High level Miocene veins in NW Otago have formed beneath the main divide of the initiating Southern Alps. Late metamorphic gold-bearing veins formed as fluid escaped from the ductile-deforming crustal root beneath Mesozoic mountains.  

Jan 1, 1997

By John E. Lens

How much trouble can narrow vertical fissures in bedrock cause on a shallow bedrock site? Enough trouble so end-bearing H-piles range between 8 and 100 feet long in a single pile cap and tiebacks range from 40 to over 100 feet long within a 10 foot wall span. Sloped bedrock surfaces also complicated the tieback installation as the drill casing followed the sloped rock surface while drilling and caused unanticipated bending (and sometimes breaking) of the drill string. Warned via pre-construction rock probes and cores reaching over 80 feet deep at the Winooski, Vermont project site, the design and construction team expected anomalies in pile driving and tieback drilling due to fissures in the bedrock filled with soil and weathered-rock. The degree of abruptness in the variability in the rock surface, and its impact on pile driving and tieback drilling were less predictable. Close monitoring of pile and tieback installation, redesign of pile caps, and lengthened tiebacks overcame these anomalous fissures. This paper shares the lessons learned for overcoming these geologic challenges to benefit designers, contractors bidding the work, and ultimately, the owner, with lower contingencies.

Jan 1, 2006

By Konstantinos Komnitsas, Evangelos Petrakis, Emmanouil Varouchakis

During the modeling of grinding systems, population balance modeling (PBM) which considers a constant breakage rate has been widely used over the past years. However, in some cases, PBM exhibited some limitations, and time-dependent approaches have been developed. Recently, a non-linear framework which considers the traditional linear theory of the PBM as a partial case was introduced, thus allowing the estimation of product particle size distribution in relation to grinding time or the specific energy input to the mill. In the proposed model the simplified form of the fundamental batch grinding equation was transformed into the well-known Rosin–Rammler (RR) distribution. Besides, the adaptability and reliability of the prediction model are among others dependent upon the operating conditions of the mill and the adjustment of the RR distribution to the experimental data. In this study, a series of grinding tests were performed using marble as test material, and the adaptability of the non-linear model was investigated using three loads of single size media, i.e., 40, 25.4, and 12.7 mm. The results indicate that the proposed model enables a more accurate analysis of grinding, compared to PBM, for different operating conditions.

Jun 24, 2023

By Lyn Jones, Mike Bratty, Rick Lawrence, David Kratochvil

"The treatment of water is required at many mining operations to remove metals and prevent the discharge of contaminated water to the environment. In other cases, water treatment is used to provide better quality water for recycle to the processing plant, or to process bleed streams in hydrometallurgical operations in order to prevent deterioration in metallurgical performance or process equipment. BioteQ Environmental Technologies Inc. has developed and commercialized the BioSulphide® Process which can provide an alternative for these treatment needs and which can also be used for profitable metal recovery, particularly in cases where conventional metal winning techniques are not economical. The BioSulphide® Process is a high rate anaerobic biotechnology for on-site production of H2S from sulphur species, although for smaller flows and metal loadings, the use of chemical sulphide reagent might be more cost effective. Both new projects and existing commercial operations, used for removal and/or recovery of copper, nickel, and zinc, and which range in sulphide generating capacity from 50 kg/day to 3.7 tonnes/day, are discussed. Particular focus is placed on the results of operations at the Raglan Mine in Northern Quebec where dissolved nickel is removed from contaminated water at a high efficiency through the precipitation of nickel sulphide. Plant effluent is discharged directly to the receiving environment and the high-grade nickel sulphide product is combined with the nickel flotation concentrate produced at the mine. The plant at Raglan will replace the existing conventional water treatment plant and will eliminate the need for on-site storage of treatment plant sludge.INTRODUCTIONThe BioSulphide® Process, which produces low cost H2S for use in selective metal precipitation, offers a low capital cost alternative which can operate efficiently and cost-effectively within a wide range of flows and solution grades. Since the technology can be used to recover metals from solutions with low flows and metal grades, the technology is also applicable to environmental applications for water treatment, with the sale of recovered metals providing an offset to treatment costs. For environmental control, the technology has a distinct advantage in being able to meet strict effluent discharge criteria due to the very low solubility of metal sulphides. To date, BioteQ Environmental Technologies has designed and constructed three plants for metal sulphide precipitation, with another three projects in the advanced development stage."

Jan 1, 2006

By H. Demirel

This paper deals with concentration of hematitic-limonitic iron ores. The ore sample obtained from Karakuz (Turkey) contain:. about 40-46 I Fe. First, a low intensity magnetic separation process was employed to separate the strongly magnetic particles cf "-10+2 mm" and "-2+0.075 mm" size fractions and magnetic concentrates with 59.1 % Fe aid % 58.0 Fe were obtained respectively. The non-magnetics of both fractions were then fed to a nigh intensity permanent magnetic separator. The Fe contents of "-10+2 nun" and "2+0.075 mm" size fractions were increased from 28.2 to 51.13 and from 35.4 7. to 43.25 respectively after single pass. Easing on these results, it was concluded that the high intensity permanent magnetic separator could he used as a pre-concentrator f.7.1- hematitic-limonitic Karakuz iron ore.

Jan 1, 1991

By Alaina B. Hanlon

Keywords: Undercooling, Convection, Dendrites, Stainless Steel, Levitation Certain Fe-Cr-Ni stainless steel alloys solidify from an undercooled melt by a two-step process in which the metastable ferrite phase forms first followed by the stable austenite phase. Recent experiments have shown that the lifetime of the metastable phase is strongly influenced by flow within the molten sample. The current research will provide insight to why flow affects the metastable phase. This new understanding will lead to the use of convection to control microstructural evolution in spray-forming of stainless steels. Simulations using a commercial computational fluid dynamics package, FIDAP, yield a range of convective flow velocities that cause mechanical damage to the dendrites which is compared to experimental results. If the convective velocities are great enough that the dendrites bend, then low angle boundaries form at the points of collision. These result in high energy sites that could serve as nuclei for the stable phase.

Jan 1, 2005

By J. Patrick Ryan, Thor H. Kiilsgaard, Charles W. Merrill, E. T. McKnight

The U.S. Treasury stocks of silver have been reduced at such a rapid rate to meet industrial and coinage requirements that they face exhaustion in 3 or 4 years. Alleviation of the silver problem will require increasing supply or reduc ing demand. This paper examines poss ible long-range resource development and research programs and improved secondary recovery. The possible reduction or elimination of silver in coinage and development and introduction of substitutes in the arts and industry are also discussed.

Feb 1, 1965

This report briefly describes the broad program of research and technologic work conducted by the Bureau of Mines on coal and related subjects during 1966. In addition to n description of investigations on mining, preparation, and utilization of coal, an account is given of the Bureau's work in mine health and safety, coal resources, mine explosives, and environmental conditions relating to coal mining and utilization. Details of most of the projects are reported in publications cited throughout this report. Centers and laboratories conducting the coal research and related investigations appear in appendix A; organizations, institutions , and companies contributing to the Bureau's coal research and technologic program are listed in appendix B.

Jan 1, 1967

A stronger U.S. economy stimulated the domestic mineral sector in 1994. Metals demand was spurred by robust U.S. motor vehicle sales, while demand for major industrial minerals rose in response to highway and building construction. Domestic mineral and material demand is expected to increase in 1995, particularly if interest rates do not restrain the building industry and international monetary exchange rates remain advantageous to U.S. automobile manufacturers. Additional information on events, trends, and issues in the mineral and material sector is presented below and in the commodity sections that follow. Overall Performance Processed materials of mineral origin produced in the United States during 1994 increased to an estimated value of $360 billion. Domestic output of raw nonfuel minerals in 1994 was estimated at $34 billion, about 6% more than that of 1993. The value of U.S. minerals production has increased in 29 of the last 34 years.

Jan 1, 1995

By Lars G. Olavson

A prototype roof bolt which can be remotely placed by pumping has been developed by the Bureau of Mines. It is known as the "Pumpable Bolt". With the objective of field testing the effectiveness of the pumpable Bolt roof support system a mining machine was developed capable of installing Pumpable Bolts in the normal production cycle of a typical underground coal mine. The machine was built and the pumpable Bolt concept tested and evaluated as a total system in shop and mine tests. The machine was operated in the mining cycle of two mines and pumpable Bolts were installed at both mine sites.

Jan 1, 1976

By Paul M. Godlewski, Joseph P. Gildner, David S. McAllister

With construction underway on the 22.5 km (14 mile) Initial Segment of the Link Light Rail transit system in Seattle (including the one-mile EPB-driven running tunnels and mined station at Beacon Hill), the Sound Transit Board on May 20, 2004 voted on selection of a preferred route for an approximately eight-mile extension northwards from the central business district to Northgate, and authorized immediate start of advanced conceptual/preliminary engineering and geotechnical exploration programs scheduled to be completed in Spring 2005. The extension includes approximately914 m (30,000) route-feet of bored running tunnels, a mined station with platform level approximately 60 m (200 ft) below grade, three (possibly four) cut-and-cover stations and a cut-and-cover cross-over structure, as well as an aerial terminal station at Northgate and other line-section below-grade and aerial structures. All tunneling will be in glacial soils.

Jan 1, 2005

By Joseph Poplawski, Christian O’Keefe, Robert Maron

"Unique and difficult minerals processing measurement situations will be described and the application of passive array-based technology for performing these measurements will be illustrated. Examples of these situations include volume flow measurements in froth lines and flotation feed lines with entrained air, slurry lines with magnetite and other magnetic ore, slurry lines with abrasive or corrosive materials, high pressure lines, and slurry and non-slurry lines exhibiting scale buildup. Other situations include measurement of entrained air levels in pipes and in flotation columns. These measurements are achieved through CiDRA’s patented passive sonar array-based technology. This technology performs two independent measurements – flow rate and entrained air amounts. Two hardware implementations of this technology have resulted in a non-intrusive flow and entrained air meter which easily is installed on the outside of the pipe, and a submersible version for entrained air or gas holdup measurements which is used in flotation processes. Recent developments in extending this technology to solve other unique measurement problems such as valve movement confirmation will be covered.INTRODUCTIONThe minerals processing industry faces many unique and challenging process control conditions and environments. In terms of flow measurements, many of these situations are not being properly served by traditional flowmeters such as ultrasonic meters, magmeters, turbine meters, orifice plate meters, vortex flow meters, Coriolis flow meters, and venturi meters. A new class of flowmeters has been developed that solves these unique situations and flow measurement problems. This new class of flowmeter technology utilizes sonar-based processing algorithms and an array of passive sensors to measure not only flow, but also fluid composition. It does so accurately, reliably and without making contact with the fluid. These measurements are performed on practically any type of fluid within virtually any type of pipe.PRINCIPLE OF OPERATIONSonar array-based flowmeters are ideal for tracking and measuring the mean velocities of disturbances traveling in the axial direction of a pipe. These disturbances generally will convect with the flow, propagate in the pipe walls, or propagate in the fluid or slurry. First let us focus on the disturbances that convect with the flow. The disturbances that convect with the flow can be density variations, temperature variations or turbulent eddies. The overwhelming majority of industrial flows will have turbulent eddies convecting with the flow, thus providing an excellent means of measuring the flow rate as described below."

Jan 1, 2008