Search Documents

By D. E. Deegan, P. M. Keeley, N. A. Rowson, T. Stachowski

An investigation into the use of Tetronics International’s thermal plasma technology based pyrometallurgical smelting process for the recovery of both platinum and rhenium was conducted. 1000 kg of Pt-Re catalysts containing 0.36 wt% Pt and 0.21 wt% Re was blended with fluxing agents, reducing agents and an iron based collector metal precursor and then fed into a plasma furnace over five individual trials at Tetronics International’s facility in Swindon, UK. Both platinum and rhenium partitioned to an iron rich collector metal phase in the furnace, which formed in-situ and accumulated beneath a less dense slag phase, derived from the inorganic substrate of the catalyst, and was easily separable. The levels of Pt and Re concentration achieved in the iron collector made it suitable for subsequent final refining. Technical recovery efficiencies of =98% for both platinum and rhenium were achieved and the concentrations of the metals in the recovered metal bullion were 2.23 wt% Pt and 1.35 wt% Re.

Jan 1, 2015

By G. Gomez Ciments-Calcia

The sources of complaints by neighbours of the operating quarry are due to the 3 following causes : - Impulsional noises or air hoch wawes – Vibrations - D u s t How a blasting in a quarry operation is felt by neighbours cannot be measured solely by the various limits set by national and European regulations regarding vibrations and air shock waves (sound pressure).

Jan 1, 2002

By G. F. Round

In order to obtain values of angle of shearing resistance and initial resistance for McMurray oil sand for use in general design calculations, the shear strength of this oil sand was measured in a controlled strain type tester, modified so that the rate of deformation could be varied between 0.01725 and 0.1869 inches per minute. Effect of temperature was investigated by adapting the equipment to operate at both 71 ° and 185 °F. The data are reported in terms of angle of shearing resistance and initial resistance for varying rates of deformation, composition and temperature. While the main sets of results reported here were obtained at a bulk density range of 108.7- 109.5 lb. / cu. ft., some results were obtained at a bulk density range of 101-102 lb. / cu. ft. Analysis of varance tables have been drawn up from the results obtained from least squares correlations and significance tests applied. It was concluded that oil content and temperature were significant variables for the degree of shear strength developed by the oil sand; increase of oil content and decrease of temperature each cause an increase in shear strength. The bulk density range 108.7 to 109.5 lb./cu. ft. gave angles of shearing resistance from 30° to 40° and initial resistance values of 0.37 p.s.i. to 0.85 p.s.i. For the bulk density range 101 to 102 lb. / cu. ft., lower values of shear strength were obtained, indicating that compaction density was also of importance

Jan 1, 1960

By J. E. Hawley

This paper constitutes a report from the Committee on Geological Research to the Geology Division of the Institute. Two years have elapsed since a formal report was made containing several resolutions aimed at assisting geological research, a review of research equipment available, a summary of research projects suggested for consideration, and a list of research then in progress (see July, 1947, Bulletin, pp. 351-370). At this time we may note what action has been taken on the various resotions and suggestions of the Committee, indicate the more important accomplishments of independent investigators, and present a summary of the rather imposing volume and variety of research currently being carried on throughout the country. I.-Committee Resolutions and Suggestions 1.-A National Advisory Committee on Research in the Geological Sciences The original resolution adopted on the setting up of this Committee was approved with despatch by Council and was forwarded to the Minister of Mines and Resources. Due to a reorganization in the Department and possibly other reasons, no action on this important matter has yet been taken, but we are assured that some time this year such a Committee will be established by the Department of Mines and Resources. Unquestionably, it will give a fresh impetus to research in the geological sciences. When the noteworthy progress made by the research committees on Geophysics and on Soil and Snow Mechanics, established by the National Research Council, is considered, it is indeed regrettable that the Department of Mines and Resources has not acted more decisively in this matter.

Jan 1, 1949

By C. Williard

Computer based mine monitoring and control systems represent a relatively new technology to be applied in the U.S. mining industry. While computer assisted engineering, design, and planning have been accepted as tools for specific technical and engineering jobs within the industry, integrating mine-wide monitoring and control systems into mining operations has been slow. This paper reviews the state of the art of mine monitoring and control systems and provides insights into future trends and developments.

Jan 1, 1988

By Michael Prince

"Managing slurry is a constant challenge for mining operations. Since slurries are not uniform, the challenge is complicated by varying rheology, velocity, temperature and pressure, all of which affect how the slurry moves through the pipeline and how destructive it is to the system it is flowing through. Picking the right equipment from the outset — the right size pipe, the right size pump and the proper valves for the application — allows mines to operate more efficiently. Better valve designs deliver multiple benefits — they can lower the cost of operations, reduce the amount of maintenance and associated downtime required and are better for the environment. Historically, modulating systems have used ball, plug and pinch valves to manage the flow of slurry, but each of these alternatives has limitations. Ball valves require ceramic lining in order to delay wear, and once a ball valve does wear, the entire valve must be replaced. Similarly, plugs in plug valves should be coated to perform in control systems, and whole valves must be swapped out upon wear. Pinch valves are expensive and only require replacement of the sleeve. However, sleeve replacement involves an extremely arduous process in which the valve is completely taken apart.Traditionally, designers have avoided using knife gate valves (KGV) in modulating systems because KGVs have not been able to hold up under the harsh operating conditions. The throttling that is required in some of these processes rapidly fatigues conventional KGVs, rendering them useless and in need of replacement. Fortunately, innovative design changes have the potential to change established views.Breaking new groundRecognizing the need for improved components, Victaulic took on the challenge of designing a valve that could withstand abrasive slurry systems for a much longer period of time. The first step in this process was to talk to miners, maintenance personnel, process engineers and operators in the field about the limitations of current offerings and then determine design specifications for an ideal replacement.Many of the responses to these inquiries were very similar and reflected challenges with current operations; the primary objective was to find a valve that would be lighter and cheaper than the valves currently in use. In theory, a lighter valve would be easier to replace, and since replacements need to be performed frequently, a cheaper valve seemed like the right idea."

Feb 1, 2019

By Sunil Bodakunta, Sreenivasa Rao Islavath

The abstract highlights the importance of determining the optimum line of extraction in continuous miner workings for improved safety and productivity. The study investigates three extraction techniques (diagonal, straight line along strike, and straight line along dip-rise) using 3D numerical modeling. The dip-rise extraction technique is found to be optimal due to lower stress and displacement, leading to a higher safety factor. The research also develops a continuous miner stability index (CMSI) to predict working face stability based on mining depth and pillar width-to-height ratio.

Apr 28, 2022

By James E. Rider

"Fractures in mine hoist drumshafts are rare. We know of no previously reported attempts to repair a fractured drumshaft; any feasible method would involve welding and the associated problems of distortion, crack formation and strength.In June 1984, a fracture was discovered in the drumshaft of the production hoist in the Teck Corporation, Lamaque Division Mine at Val d'Or, Quebec. Delivery time on a new shaft would have been at least six months. The shaft was repaired in ten days and the total out -of-service time was four weeks.This paper describes why the shaft failed, how it was repaired, and the special alignment procedures employed during re-installation to minimize stresses in the repaired area.IntroductionThe performance of a mine hoist drumshaft is absolutely critical to mine operation. An inoperable drumshaft means no hoist, which in turn means no production or mine operation.Fractures in mine hoist drumshafts are rare. Previously when they have occurred, no one has seriously considered attempting a repair because of problems involved. Any feasible method would involve welding, which raises several major problems - namely, metallurgical, alignment, and strength.In July 1984 this very situation occurred at the Teck Corporation, Lamaque Division Mine in Val d'Or, Quebec.It was recognized that a new shaft would take at least 6 months' fabrication and delivery time. However, having had some experience at repairing broken shafts in other machines under similarly desperate circumstances, and after due consideration, it was concluded that by applying the correct techniques and engaging the right expertise, it would be possible to perform a repair and have the mine back in operation within a month.Thanks to outstanding efforts by all, the repair was accomplished in ten days and total out-of-service-time was only four weeks. The causes of the failure were determined and the calculated stress levels confirmed by strain gauge measurement during operation.The success of this project was achieved by adhering rigorously to fundamental management and engineering principles."

Jan 1, 1988

By Markus A. Reuter, Robert Matusewicz

"Consumer products are a complex man-made mixture of sometimes in excess of 50 elements. In order to recover these complex mixtures of elements either as metals, compounds or energy requires versatile technology in physical separation but also smelting and energy recovery. This paper explores this by referring to the innovative application of Top Submerged Lance (TSL) technology and associated theoretical and environmental aspects to process (recycle) post consumer materials and industrial intermediate products and residues. A diversity of applications has been tested in Ausmelt’s pilot plant in Dandenong and many have gone to commercial scale globally. This paper reviews the varied applications ranging from e-waste recycling, lead and NiCd battery recycling, metals recovery from slags, zinc leach residue processing, electric arc furnace (EAF) dust, Municipal Waste Incinerator bottom ash processing, carbon containing residues such as retort ashes and spent pot liner from the aluminium production process as well as use of the technology for materials such as automotive shredder residue (ASR) and plastics. Introduction The modern resource cycle is a link between primary production of metals linked to the recycling of post-consumer goods. The sometimes complex combinations of materials and metals in consumer products such as televisions depicted by Figure 1, does require a range of technology to recover materials, metals and energy for reuse and/or recycling in an economically feasible as well as environmentally friendly manner."

Jan 1, 2008

By F. B. Plummer

PERHAPS the greatest progress made in the technical methods of oil production during the last year has been in handling gas from the new fields that yield light distillate fractions. At least sixteen recycling plants have been perfected and installed in South Texas fields alone during 1939 having a daily capacity of more than one billion -2 cubic feet of gas and capable of producing more than a million gallons of distillate daily. The process consists of running the gas under pres- sure through especially designed plants, separating out the condensate, then compressing the gas to 3000 lb. or more, depending on the subsurface pressure in the formation, and injecting gas back into the reservoir to be produced again later, along with more of the liquid hydrocarbons, and again recycled. Hence production in these distillate fields in sense has changed from that of producing a constantly diminishing and much-wasted product to a more or less continuous manufacturing process, in which practically all the gas is conserved-a real triumph in engineering practice.

Jan 1, 1940

By G. ALBORNOZ, S. Utili, A. AGOSTI, C. VALDERRAMA, R. PELL, N. Morales

The steepness of the slopes of an open pit mine has a substantial influence on the financial return of the mine. The paper proposes a novel design methodology where overall steeper pitwalls are employed without compromising the safety of the mine. In current design practice pitwall profiles are often planar in crosssection and the profile in between ramps especially tend to be planar and defined by a constant inter-ramp angle. Sometimes rock layers exhibiting different strengths require the inclination of the profile to vary with depth, but the inclination across each layer is usually constant. Here instead, a new geotechnical software, OptimalSlope, is employed to determine optimal pitwall profiles of depth varying inclination. OptimalSlope seeks the solution of a mathematical optimization problem where the overall steepness of the pitwall, from crest to toe, is maximized for an assigned lithology, geotechnical properties and Factor of Safety (FoS). Bench geometries (bench height, face inclination, minimum berm width) are imposed in the optimization as constraints which bind the maximum local inclination of the sought optimal profile together with any other constraints such as geological discontinuities that may influence slope failure. The obtained optimal profiles are always steeper than their planar counterparts (i.e. the planar profiles exhibiting the same FoS) up to 8 degrees depending on rock type and severity of constraints on local inclinations. The design of a copper mine is first carried out employing planar pitwalls, secondly adopting the optimal pitwall profiles determined by OptimalSlope. The adoption of optimal slope profiles leads to a 34% higher net present value and reductions of carbon footprint and energy consumption of 0.17 Mt CO2 eq and 82.5 million MJ respectively due to a 15% reduction of rockwaste volume.

Mar 2, 2022

By H. L. Gibbs

A portable radon monitoring instrument capable of making on-the-spot measurements of the radon gas content of uranium mine atmospheres was designed and constructed. The monitor was tested in the laboratory and in operating uranium mines. Good correlation was obtained between the monitor readings and radon measurements made on mine atmosphere samples taken in radon bottles.

Jan 1, 1973

By Joseph Hirschi, Naga S. Y. Tirumalaraju, Aditya Mishra, Anthony (Sam) J. S. Spearing

"Primary roof support in underground coal mines in the USA consists mostly of fully grouted passive rebar or grouted (partially or fully) tensioned rebar. Research conducted at two room-and pillar coal mines in the Illinois Basin and one longwall mine in Colorado monitored the performance of these passive and active rock bolts under similar geologic and mining conditions and found no significant initial loads in either passive or active rock bolts (Spearing et al., 2011). Active rock bolts showed significant loss of initial pre-load, although the exact reasons for this were not fully investigated. Subsequent laboratory testing has also shown that in weak rock, resin creep occurs, caused by slippage of the mechanical key between resin column and rock interface. These creep tests were studied in the laboratory in an effort to quantifythis phenomenon.INTRODUCTIONResin-grouted rock bolts are the first and main line of defense to counter roof and rib falls in underground coal mines of the United States. Rock bolts are categorized as active or passive. Active bolts are tensioned during installation whilst no (or limited) tension is applied to passive bolts, which need subsequent strata movement to generate reactive loads. During installation of passive bolts, some reactive pre-load may be generated by a significant up-thrust from the rock bolter boom.The selection of active or passive bolts is critical and is mostly dependent on the conditions and properties of the immediate roof (Unrug, 2009). This decision is frequently made based on personal experience, bias, and most recently cost. Active bolts are generally used in cases of highly laminated roof rock. When active bolts are tensioned, they develop compressive forces between these layers forming a beam, which helps to stabilize weak individual layers thereby increasing frictional forces between layers and decreasing effects of horizontal stresses. The fully grouted tensioned rebar system is high in stiffness as compared to mechanical bolts and provides higher surface area of contact along the length of the bolt due to the grout, which permits it to develop a strong anchorage mechanism."

Jan 1, 2015

By William Detty

An architect representing the Atlanta office of the Brick Institute of America periodically presents a slide lecture to interested groups entitled "The First 10,000 Years of Brick". The title signifies the fact that brick, man's oldest manufactured building material, has been around for quite some time and will continue to be utilized by architects and builders in the foreseeable future. This is not to say that the brick industry can rest on its laurels and ignore the competition presented by newer more innovative products. The industry will have to be equally inovative and market oriented in order to maintain its market share of the predicted construction boom between now and the year 2000. The implication is made, however, that brick can be produced under rudimentary conditions and that the desire to use the product has been long standing. In addition, history has sham that there has been plentiful clay available to produce the product. This paper is an attempt to assess the climate in which the brick industry will operate during the next 26 years. An analysis of regulatory conditions affecting the manufacture of the product will be followed by an assessment of the materials environment in which the industry will be operating. These factors are then reconciled with a projected demand for the product to determine the ability of the industry to satisfy future demand for brick. From a mineral point of view this paper will address itself generally to the availability of and demand for clay. However, other than a brief overview of the uses of other specific types of clay, it will concentrate on the clays utilized in the production of structural clay products, specifically brick.

Jan 1, 1974

By J. C. METCALF

MORE than 80 per cent. of the iron produced in the United States and over 30 per cent. of the world's annual production is obtained in the Lake Superior district. Though iron ore was discovered on the Marquette range in 1844, the poor transportation facilities retarded the development of this region for many years. The structure of the Lake Superior basin is essentially an east-west synclinorium with steep dips on the south side of the lake and considerably flatter ones on the north and west. The Upper Huronian series, which -is the iron-bearing one of the formation, on the south side of the lake dips north from 55' to 80°, and on the north side dips south from 8" to 200. The series has been subjected to local folding and faulting, which have influenced the development of the mining systems used.

Jan 1, 1921

Many block caving operations experience difficulties during undercutting, resulting in draw horizon damage, production loss and extensive drift repairs for the life of the block cave. This paper deals specifically with block cave undercut aims strategies, methodologies and management to avoid the problems indicated above.

Jan 1, 2000

By Yoshio Hiramatsu

In Toyoha mine near Sapporo, the ground temperature is very high, perhaps due to inflow of hot mineral water, the origin of which may be rock masses intruded by the igneous activity in the Tertiary period. The rock masses are found about 2 km east of the mine, their temperature being estimated at from 770 to 870 K at a depth of 3 km. In this mine several veins bearing zinc and lead ores have been mined down to the depth of 300 m from the level of the main entry, of which altitude is 551 m above the sea level. Formerly no attempt was made at development of the deeper part of the mine than the 350 m level from the main entry. Let us indicate hereafter the levels in this mine in such a way that the level 300 m deep from the main entry is denoted as 300 mL. Since 1974, however, the 450 mL of Tajima vein has been developed by deepening No. 5 Shaft to, and by driving drifts in the level. Much hot mineral water has been flowing into the drifts from rock. After twenty-eight months from the beginning of development, the total length of excavation amounted to about 1300 m. The success in development so far may be attributed to cooling rock and air with chilled water and to adopting heat-resisting explosives and detonators. This cooling costed very much and for further development in this level a more effective and economical cooling is desired if possible. To obtain fundamental data for designing an economical cooling, the authors investigated, as a preliminary study, the heat balance in the main drift of 450 mL, by measuring the temperatures of air, rock, hot mineral water, the rates of flow of air and water and so on, in August 1976. They are now carrying out continual measurements of the variations in rock temperature, air temperature and humidity with time. The present paper describes the details of the preliminary study.

Jan 1, 1980

By Gary G. Grim

The reliable performance of the coal reclaim system is essential to the continued availability of a coal-fired electric generating unit. The control of fugitive coal dust within the areas housing the reclaiming equipment is necessary not only to minimize maintenance and clean-up costs, but is also a safety and health consideration. This paper describes the reclaim system control and dust suppression systems as initially installed, the shortcomings of these systems and the steps eventually taken to correct these shortcomings.

Jan 1, 1983

By S. Frederick Ravitz

JUDGING from the inquiries that are constantly being received by the Utah Engineering Experiment Station as to the "Why," so to speak, of the flotation process of concentrating minerals, it occurred to me that perhaps a brief statement of the more important theories might interest those who have not followed the technical literature. Like many other industrial processes, flotation has hitherto been developed on an almost purely empirical basis, with relatively little practical contribution from the fundamental chemistry and physics on which the phenomena are based. In fact, its development by the trial - and - error method has been perfected to such a high state that it is becoming generally thought that further important advances can be brought about only by a thorough understanding of the actual mechanism of the process. Natur¬ally, such a complicated process has brought forth numerous theories, most of which have failed to withstand the test of time. It is significant that no theory has yet been advanced which is universally accepted.

Jan 1, 1933

By John T. Wizzard, R. P. Killmeyer, B. S. Gottfried

The Coal Preparation Branch of the Pittsburgh Energy Technology Center has developed a computer program to calculate the performance characteristics of coal washing devices. This program uses specific gravity analyses of the clean coal and refuse streams as input, and generates dependent and independent performance criteria for the washer. Partition curves are internally represented in a functional form by a Weibull function. Performance criteria generated by this computer program are compared to manually calculated performance criteria for air tables, Dynawhirlpools, Baum jigs, hydrocyclones, and dense medium cyclones. The comparisons show that the computer program gives results in close agreement with the hand- calculated values while greatly reducing the amount of time involved in performing the analyses.

Jan 1, 1983