Search Documents

By Kenneth H. Johnston

This publication describes a thermal-recovery project and two waterflood projects in Carter, Garvin, and Stephens Counties, Okla., that will be visited during the 1966 annual tour by the Bureau of Mines in cooperation with the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects arc (1) the movement of heavy (15° to 28° API gravity) crude oil through the reservoir and into the well bore with energy furnished by burning a portion of the crude oil therein; (2) the use of an inverted nine-spot pattern with dually completed injection wells, to produce oil from deep (8,200 to 10,200 feet) reservoirs; and (3) the flooding of five sand lenses separately by using controlled water injections through multizone completed injection wells. Discussion of the individual projects includes information on their early history, method of completing and operating wells, source and treatment of injection fluids, oil production decline curves, and the results obtained from the development.

Jan 1, 1966

By Kenneth H. Johnston

This publication describes a thermal-recovery project and two waterflood projects in Carter, Garvin, and Stephens Counties, Okla., that will be visited during the 1966 annual tour by the Bureau of Mines in cooperation with the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects arc (1) the movement of heavy (15° to 28° API gravity) crude oil through the reservoir and into the well bore with energy furnished by burning a portion of the crude oil therein; (2) the use of an inverted nine-spot pattern with dually completed injection wells, to produce oil from deep (8,200 to 10,200 feet) reservoirs; and (3) the flooding of five sand lenses separately by using controlled water injections through multizone completed injection wells. Discussion of the individual projects includes information on their early history, method of completing and operating wells, source and treatment of injection fluids, oil production decline curves, and the results obtained from the development.

Jan 1, 1966

The works recorded in this Test Report have been performed by Rade Roncar - Electrotechnical Institute of Zagreb, SFR Yugoslavia in collaboration with Bureau of Mines. The main objective of these investigations was to investigate the possibility of fabrication of thin-walled square enclosures of satisfactory safety factor in accordance with requirements of effective technical regulations. The results and the investigations can be divided in three main fields: - investigations of thin-walled enclosures with the view of determination of pressures causing technological deformations before performing tests in accordance with effective applicable regulations, - finding the safety factor by means of tests of metal-foam pressure vents, - comparison of enclosures with and without pretreatment by technological deformation.

Jan 1, 1987

By J. -G. Swanson

Dust control in longwall coal mining depends primarily on the prevention of dust at the source and secondarily on the suppression of airborne dust. One of the primary methods for the prevention of dust is the wetting of the coal face prior to extraction, which can be achieved with water spray systems installed on the shield supports. The spray droplets must travel across the airway to the longwall face, where high ventilation air speeds can entrain water droplets and prevent them from reaching the face thus minimizing the dust control at the source. Through an evaluation of spray plume characteristics in a wind tunnel, the droplet size and droplet drift behavior was determined. This drift behavior was examined by evaluating the spray plume concentration drop and the droplet size shift near the nozzle exit at varying air speeds. Based on these evaluations, CFD modeling was applied to simulate the spray behavior for varying geometries. These results led to the selection of appropriate spray nozzles capable of carrying water droplets to the face at higher air speeds, resulting in an adequate wetting of the coal face and reduced dust generation.

Jan 1, 2012

By A Cox

It has been demonstrated that all the cadmium from spent batteries, typically 4 g per battery, can be recovered by burning polyvinyl chloride waste to yield hydrogen chloride; this reacts to produce volatile calcium chloride, which can then be condensed and collected in a separate reactor. Alternatively, chlorine may be used to chlorinate the cadmium with equal efficiency. There is also a prospect of using very low concentrations of these gases, less than 1%, to effect the separation. The Cd was recovered more quickly when exposed to sustained, controlled flow rates of chlorinating gases, whereas when PVC was burnt most of the gas was produced in a very short time, not allowing complete reaction. This problem can be overcome by recirculation of the gas into the reactor. The technology is efficient and clean and the equipment used is simple, enhancing the prospects for a pilot-scale version of the process

Jun 21, 1905

By Sam S. Taylor

Subsurface disposal of oil-field brines was practiced in Oklahoma on a limited scale as early as 1925. The technique of subsurface injection has been improved immensely and has been applied with varying success in many oil-producing areas in Oklahoma, and elsewhere. This method of disposal, however, is only one of several methods available to operators of oil-producing properties, but, in contrast with usual methods of handling brines on the surface it eliminates the damaging effect of mineralized water on fresh-water supplies, vegetation, and aquatic and other animal life. Other methods of brine disposal approved by regulatory agencies in some States include (1) impounding in impervious ponds and solar evaporation, (2) controlled diversion into surface waters, and (3) recovery of the mineral salts of the brine. In most States where oil is produced regulatory bodies authorize the use of one or more of these methods of brine disposal. In Oklahoma, for example, the .Oklahoma Planning and Resources Board of the Conservation Commission has been authorized4/ to adopt whatever methods or means may be necessary to prevent contamination by mineralization of all potable waters within the State.

Jan 1, 1942

By W. K. Connor, O&apos

The U.S. Bureau of Mines investigated the Sheep Creek prospect in the north-central Alaska Range to evaluate the Pb, Zn, Ag, and Sn resources. The studies included field investigations, mineralogical characterization, and concentration tests. Mineralization at Sheep Creek consists of disseminated, banded, and massive pyrite, sphalerite, and galena. Tin occurs as grains of cassiterite (Sn02) in the quartz-mica matrix and within pyrite and sphalerite grains, and Ag occurs in solid solution within the galena. Three bulk surface samples and two sets of core samples were collected at the Sheep Creek prospect for this study. Gravity concentration yielded products with up to 30 pct Sn, and the best result was a product that recovered 52 pct of the Sn at a grade of 22 pct Sn. Bulk sulfide flotation yielded products that recovered up to 89 pct of the Zn, 73 pct of the Pb, and 75 pct of the Ag, but grades were relatively low; selective flotation would significantly increase the grades.

Jan 1, 1989

By William A. Stickney

The zirconium-hafnium separation plant at Albany, Oreg., was the result of a chain of events that started with studies by A. R. Kaufmann at the Massachusetts Institute of Technology. Variations in the listed neutron-absorption cross-section of zirconium caused him to suspect a misprint. As a result of these discrepancies and following his suggestions, Oak Ridge scientists made studies establishing a value of 0.4 barn or lower. This meant that the potential of zirconium for reactor application was greatly enhanced. Since hafnium is invariably associated with zirconium and has a high neutron cross-section, it was necessary that an efficient hafnium-separation method be developed before the superiority of zirconium as a structural material in nuclear reactors could be realized. The Albany plant was built and operated for the Atomic Energy Commission (AEC) under Letter Agreement AT-(11-1) -140, patterned after a plant operated by the Carbide and Carbon Chemicals Corp. at Oak Ridge, Tenn. Construction was begun in April 1951. Hafnium was to be extracted preferentially as hafnium thiocyanate from an aqueous mixture of zirconyl and hafnyl chlorides in hexone (methyl isobutyl ketone) by a liquid-liquid countercurrent system.

Jan 1, 1959

By H S. Smit, P Lotz

Gold mining companies who are signatories of the International Cyanide Management Code (visit www.cyanidecode.org for further information) are required to measure WAD cyanide on-line and destroy WAD cyanide in excess of specified limits. Weak acid dissociable (WAD) cyanide refers to those cyanide species liberated at a moderate pH of 4.5 such as HCN(aq) and CN-, and the majority of Zn, Cd, Cu, Ni and Ag complexes with low dissociation constants. It is potentially toxic to humans and animals. Recognising and in response to the gold mining industryÆs need for an on-line WAD cyanide measurement device, Mintek recently developed the WAD Cynoprobe. The WAD cyanide analysis technique is based on the use of a ligand exchange reagent that liberates WAD cyanide from metal-cyano complexes. The ligand exchange reaction is represented by the following chemical equation: Metal(CN)X + yLigand <-> Metal(Ligand)y + xCN- The plant filtrate is treated with a ligand exchange reagent, to liberate WAD cyanide, before measuring the free cyanide concentration via amperometry. The instrument proved to be accurate and reliable in the laboratory as well as under industrial gold plant conditions during various trials. It has gained wide-spread commercial acceptance both locally and internationally. However, itÆs recent exposure to complex ore types have called for refinements to the analysis technique. It has been further developed to improve its precision and accuracy and to remove reagent and thiosulfate interferences. Its compatibility with the most commonly used destruction oxidants has also recently been investigated. The WAD Cynoprobe may be configured to measure both free and WAD cyanide concentration. Its fast analysis time, approximately 5 min, makes it suitable for use in the control and optimisation of the cyanide destruction and recovery process. Proper oxidant dosage control and monitoring of effluent concentration levels will ultimately result in less cyanide and post-destruction salts discharged into the environment.

Jan 1, 2008

By Dan Mahrt

"In June of 2009, a slope failure occurred along River Road in Bismarck, North Dakota. The slope failure affected approximately 300 feet of River Road with vertical displacements up to 3 feet, resulting in closure of the road. River Road travels along the Missouri River in Bismarck in a geologic area riddled with historic slope failures of varying sizes. River Road is a city roadway which travels along the Missouri River. The toe of the failure extended into the Missouri River, therefore methods to repair the slope needed to be constructed within United States Army Corps of Engineers (USACE) requirements, and be acceptable to the City of Bismarck. As this is a scenic area along the river, the stakeholders desired to maintain the scenic landscape along the roadway as a part of the slope stabilization.Due to the magnitude movement of the failure mass, the geometry of the failure was relatively easy to evaluate. In evaluating remediation options and collaborating with the USACE, the team determined that the scarp was situated primarily within the navigable portion of the Missouri River. This required USACE approval for any repair or remedial work downslope of the roadway. The City of Bismarck wished to reopen the roadway as soon as possible, therefore stabilization options were limited to working within the road right-of-way to avoid permitting for working within the navigable waterway.The remediation solution for this project involved a combination of driven H-pile and placement of lightweight fill to re-construct the roadway at the original grades, and avoid impacting the navigable portions of the Missouri River. This paper discusses the unique project constraints and the innovative solution using multiple technologies to successfully stabilize the slope.BackgroundIn June 2009, Bismarck, North Dakota experienced two consecutive days of significant rain resulting in over 5 inches of precipitation in a 36-hour period. Shortly after these rain events, a slope failure was noted on River Road, a city street along the Missouri River in Bismarck. Initial findings noted the slope failure affected about a 300-foot long portion of the roadway, with vertical displacements of about 2 feet. The city of Bismarck closed the roadway and began evaluating repair solutions for the road."

Jan 1, 2016

By John H. Perry

Strata III is a full-spectrum roof control system which provides the mine operator the ability to upgrade his roof control in place. The procedure is easily adaptable with current roof bolting techniques. To use the system, the operator starts by installing a special hollow core mechanically anchored roof belt during the roof bolting cycle. This bolt can be upgraded to a fully grouted tensioned rebar bolt by injecting StrataGee G-300, a special polyurethane grout, around the bolt through an injection port in the roof plate. This same bolt can then be used to inject RokLok binders for roof consolidation by pumping the binders through the core of the bolt. This concept in roof control was developed to provide the mine operator a flexible way to maintain roof control in areas which deteriorate over time, or must be kept open for long periods of time. Possible locations of use would be: longwall set-up rooms, recovery rooms, headgates, intersections, and belt entries.

Jan 1, 1987

By N. Barton

Large scale tests were conducted on quartzitic gravel and crushed sand-stone to investigate pertinent geotechnical properties for backfill support of egress shafts. Such shafts are envisaged for rapid launching of deep-based missiles. The backfill support is designed to resist shaft closure under dynamic loading, and must also drain rapidly to a lower catch chamber to allow launching. Large scale tilt shear tests were performed to measure the internal shear strength of the two backfill materials. Shaft filling and emptying tests were conducted in a 12 ft deep, 3 ft diameter model section of shaft drilled in sandstone. One half of the model was smooth bored, the other half rough-surfaced to represent drill and blast surfaces. Vertical and horizontal pressure cells indicated that stress only built-up during the first 1 to 1 ½ diameters of filling, due to the high-sidewall friction of 38° for the rough shaft and 31° for the smooth shaft. Interface sliding tests were performed to confirm these figures. Static and dynamic deformation tests were also per-formed, and indicated moduli as high as 56,000 psi, which will give excellent shaft support. Both the shaft support characteristics and the ease of emptying of gravel look particularly promising.

Jan 1, 1983

By W. F. Van Impe

The design of piles and of pile groups has remarkably progressed over the past two decades. The in­creasing complexity of the building concept implements a more rational approach of the deep foundation capacity and its interaction with the structure. Moreover, the understanding of the soil characteristics relevant to deep foundation behaviour, is continuously in progress because soil parameters are always more accurately determined; which also contributed a lot to the recent developments in pile capacity design. At last, due to the increasing sensitivity of buildings to deformations, continuous attention must be also paid to pile group settlements. The aim of this report is to discuss some of the mentioned more important pile design developments.

Jan 1, 1994

The mining industry continues to be a major driver of the Australian economy generating over A$130 billion in export earnings in 2008/2009. However, the industry has been cited as a significant contributor to green house gas emissions. Australia's proposed carbon trading scheme, the Carbon Pollution Reduction Scheme (CPRS) will financially impact on mining operations; this calls for a holistic planning approach for mining operations taking into account the impact of the emissions trading scheme. Since carbon trading is a new area of study, particularly within Australia, the quantitative effect of the CPRS on the mining industry is uncertain and current mine planning practices do not directly consider emissions. This paper presents results of the study into the impact of the CPRS on a hypothetical large scale open pit operation, using a spreadsheet model based on linear programming and simulation. By varying the production rates, life of mine (LOM), carbon price and ore grades among other variables several scenarios were simulated to determine the impact of emissions trading scheme on the net present value of the project. This study found that the adoption of the proposed Carbon Pollution Reduction Scheme could impact mining operations in Australia by a three per cent to six per cent reduction in net present value, for carbon credit costs of $25/t to $50/t respectively. While the six per cent reduction in net present value for a mining operation is significant, rising fuel prices have had a similar effect in recent years. The most energy-intensive processes are the milling circuit and the flotation concentrator circuit. These processes are jointly responsible for up to 60 per cent of the total emissions, depending on the production rate and the level of offshore processing conducted. Clearly, the introduction of the CPRS makes it is imperative for mining companies to assess the impact of carbon emissions on a mining project during mine planning.

Dec 6, 2010

The pyrite-sphalerite-galena and barite orebodies at the Rosebery mine are concordant with the shale host rock and have been deformed into one system of folds with an associated axial plane cleavage. The folds are tight and overturned with east-dipping axial planes. Folds in the sulphide ore are commonly disharmonic, particularly between adjacent bands of different composition.Concentric style folds occur in the competent bands, e.g. pyrite-rich bands. Similar style folds are predominant in the less competent sphalerite-galena-rich bands and also in the shale of the host rock. The trends and plunges of the fold hinge-lines are variable but axial planes are of reasonably constant orientation throughout the mine area. The folds in the orebodies are of limited axial extent, approximating to conical folds, and are arranged in en echelon patterns. The fold system was possibly formed in one period of folding by heterogeneous strain that may have been caused by the presence of a mass of tectonically mobile sulphide ore. Lineations parallel to the ore/host rock contacts appear to reflect movement between the ore and the host rock during folding.

Jan 1, 1972

By John A. Organiscak

The Bureau of Mines conducted a survey of eight shearer longwall operations to identify factors that affect respirable dust generation from longwall roof supports. The longwalls surveyed were in coal seams located in different geographic regions of the United States. Data were collected on mining (geologic) conditions, support design, operational characteristics, and amount of respirable dust generated from roof supports. Analysis indicated that mining conditions are the main factors that affect the generation of dust during roof support movement. Both roof strength and depth of cover above the coal seam showed relationships with the amount of support dust generated. Several practices are currently employed to effectively control roof support dust; however, some of these controls are limited. More research and development is needed to improve dust control technology for longwall roof supports.

Jan 1, 1985

By L. G. Stolarczyk, J. Duncan

"SynopsisLong before the environmental movement, coal miners were suffering from occupational diseases that became apparent in the later years of service, and especially during the retirement years. Chronic exposure to micro-fine dust in the respirable range (‘float’ dust) causes various lung diseases, referred to as coal mine dust lung disease. In the USA alone, 76 000 miners have died of coal mine dust lung disease since early legislation recognized the issue in 1969. Researchers believe that reducing float dust exposure limits alone will not reverse the increasing incidence of coal mine dust lung disease seen in the current generation of miners. Trace and radioactive metals are concentrated in the thin boundary layers of the coal seam (Roberts, 2013), and hence float dust includes silica and toxic trace metals. The production and quality of coal is also significantly impacted by the presence of these contaminants in the coal. In the combustion process, the trace metals are oxidized and become incorporated in the fly ash and flue gas. Since they are extremely water-soluble, they represent a significant danger to health and the environment. Coal preparation plants and power stations need to mitigate these contaminants as far as is practical, but the simple fact is that most contaminants should have been left un-mined.This paper describes an innovative coal-cutting solution to the longstanding technology gap in mining – the ability to measure uncut coal layer thickness to the boundary rock layer. Because of constant changes in geology, seam thickness, and seam undulation, the horizon sensor must be located in the bit-block of the rotating cutter drum of the mining machine. Contaminants in ROM coal must be minimized at the source – that is, at the rock/coal crushing cone directly under the bit-tips of the cutting drum. Bittip distances to the rock boundary layer must be automatically controlled in real time when mining in a complex and undulating coal bed. Horizon sensing (HS) technology enables the mining machine’s cutting picks to stop at a specified distance from undulating horizons of the boundary rock. The thin contaminated coal layer can be left in situ, significantly reducing the toxicity of the float dust. Preventing the metal picks from striking quartz-containing boundary rock also reduces the occurrence of methane ignitions. HS technology equipped with pick force vector sensing can allow optimization of the cutting pick lacing pattern for minimum coal and rock crushing, thereby reducing float dust. This technology may enable the mining industry to convert from automated machine control to autonomous during coal cutting and loading."

Jan 1, 2015

By E. Kamon

This report summarizes completed research pertaining to the reaction of human subjects exposed to Self-Contained Breathing Apparatus (SCBA) stressors during escape conditions (viz., resistance breathing, C02 breathing, hot air breathing, and static positive facepiece positive pressure breathing) and the development of an automated breathing and metabolic simulator (ABMS). Volume I contains summarizes of the studies performed under this contract. Volume II is an appendix which contains more detailed descriptions of these studies.

Jan 1, 1984

By R. R. Faddick

Properties of coal-water slurries were studied in two separate phases: a rheological phase and a pipeline phase. The purpose of the study was to investigate the rheology of fine coal slurries to determine the effect of fine particles in a coal-water mixture on the economic and operational aspects of a slurry pipeline. The slurries consisted of 6x10, 100x200, and 200x0 mesh coal in water. A fourth slurry consisted of a mixture of the 6x10 and 200x0 mesh coal. Brookfield and Stormer rotational viscometers were used to obtain or simulate rheograms for a range of fine coal concentrations, temperatures, and particle sizes. All the slurries were pumped through a 1-inch diameter acrylic pipe. The fine coal slurries were found to encompass four distinct rheological models. The narrow size distribution of the coal slurries was apparently responsible for the high pipewall friction losses, more so than the particle size. A scale-up method applicable to Bingham plastics was found satisfactory for predicting pipeline headlosses of fine coal slurries from rheology data.

Jan 1, 1974

By P. Golledge, A. D. S. Gillies

An investigation has been carried on samples of three Queensland coal dusts to determine the potential explosibility of dust-gas mixtures. The explosion potential of the samples was classified by the lean and rich limits of explosibility and the limiting oxygen concentrations for each sample. Plotting of these points showed 2-dimensional flammability limit surfaces for coal dust/oxygen, methane/oxygen and coal dust/methane mixtures. From these plots the 3-dimensional flammability envelopes defining the explosibility of the mixtures were defined. The explosion limits of the coal dust/methane/oxygen system were seen to be influenced most by the explosibility characteristics of coal dust. Methane exerted a stronger influence over the explosion limits when the coal had a low volatile content

Jun 19, 1905