Search Documents

By R. L. Crosby

From studies of wrought magnesium alloys containing rare-earth elements, data are presented on the mechanical properties of the alloys at room temperature and at temperatures of 100°, 200°, and 300° C. Results of studies of the solid-solubility of cerium and zirconium in magnesium as determined by electrical resistance measurements are also discussed and are compared with those of other investigators. The strength of magnesium-cerium alloys did not increase with the addition of vanadium and titanium dioxide. The addition of zirconium increased the tensile strength of the alloys as much as 10,000 p.s.i. at room temperature, but this increase diminished above 100° C.

Jan 1, 1962

By Henrique Hipolito, Caio Alves

Waelz process is a method applied in the zinc oxide production and is one of the largest sources of carbon emissions within the zinc industry. The solid carbon used for heating and for reduction reactions is provided mainly by the coke fed with the EAFD in the Waelz kiln. Both chemical composition and physical properties of the coke are important to transportation and to the process. Decarbonizing the Waelz process by replacing the traditional fuel source using alternative biogenic fuel, for example, offers a potential solution to reduce the carbon footprint, which is aligned with the ESG perspective.

Sep 29, 2023

By R. J. Leary

This investigation was conducted to determine the effects of various rare-earth metal addition practices upon the macrostructure and the pattern of sulfur distribution in steel ingots. Heats of plain carbon steel were melted in a 1-ton, basic electric-arc furnace. Melts were treated with mixtures of rare-earth silicides, aluminum, and cryolite either in the furnace before tap or in the ladle after tap to determine the effects of this form of rare-earth treatment upon ingot macrostructure. Steels thus treated with rare earths in the furnace were characteristically free of the gross subsurface nonmetallics which typically result from conventional rare-earth treatments. Steel treated in the ladle showed only a few such nonmetallics, and practical techniques were developed for eliminating most of these. Results showed that furnace deoxidation was controlled by the concentration ratio of rare earths: aluminum. During casting, deoxidation was controlled by the concentration of rare earths. Oxygen contents equivalent to vacuum ladle degassing resulted from air-melt furnace treatments with the rare-earth mixtures described. Rare earths in steel inhibited the onset of equiaxed grain formation during ingot freezing, and also virtually prevented interdendritic segregation of sulfides.

Jan 1, 1968

By Norbert L. Piret

From the copper smelter operation a various outputs are to exert negative impacts on the environment. Particularly, emissions like SO2 and dusts, solid wastes like contaminated gypsum and arsenic sludge, effluents and heated cooling water are generated. Most countries have sitipulated an environmental legislation to provide the framework for an efficient environmental management. As part of the planning activities for x major greenfield copper smelter, the Following elaborations are required and were drawn up. -The Environmental Impact Assessment which is the first step of environmental management and mandatory for every new project. - The Environmental Monitoring Plan, which describes the monitoring procedures for the main impacts identified and assessed. -The Environmental Management Plan, which deals with the minimization of environmental impacts, and the methods of its implementation.

Jan 1, 1996

By William R. Wayment, Wayne S. Cusitar

INTRODUCTION The process of mining removes valuable and eco¬nomically recoverable minerals from the earth. In the case of hard-rock mining, this process involves breaking and removing ore, while leaving the waste rock or host rock as intact as possible. Prior to mining, ground stresses exist in the ore and the host rock as a result of weight and tectonic forces; for the purposes of this chapter, the ore is considered to support the host rock on both the hanging and footwall sides. Two basic phenomena accompany mining. First, the hanging walls and footwalls tend to move together as the ore is removed. Second, high stress gradients de¬velop in the rock periphery of the opening; the magni¬tudes of the stress gradients vary widely, depending upon the local geometry and conditions. At various times, mining methods have used square¬set timbers, waste-rock backfill, alluvial sand fill, and tailings backfill materials, with or without cement, to replace the loss of support caused by the removal of the ore. Cut-and-fill mining has evolved to use hydraulically placed tailings for the backfill. In the stope, this fill provides massive support to the walls, thereby reducing stresses in the back. It also provides a floor from which men and machines can work to drill and blast, to haul ore, and to scale and bolt the back. In many cases, the addition of cement provides a competent free-standing wall when the fill is exposed during mining of adjacent stopes or during pillar recovery operations. In most cases, the use of fill does not eliminate standard tem¬porary or local roof control measures such as roof bolts and wire mesh. Fill Characteristics It is important that backfill used for ground support be of maximum stiffness in relation to wall closure. The stiffness of the fill is related to its placement bulk density or void ratio. In the case of cemented tailings, this is enhanced by the cement bonds. During stope closure, individual fill particles experience rotation and crushing at point contacts, but they are subject to little relative translation. The stiffness approaches infinity as the void ratio approaches zero, until the ground forces reach equilibrium, and closure stops. The gradation of particle sizes and minimal segregation resulting from good hy¬draulic placement both contribute to a high degree of early stiffness in the closure history of classified tailings backfill. This also implies that the fill should be resistant to creeping under high static loads. All mines experience shock loading situations such as blasting, and many mines experience rock bursts that can apply sudden and very high loads to the fill. Certain conditions of void ratio, particle size, and moisture con¬tent can result in mass fluidization of unconsolidated fill during such shock loading. Two key factors in avoid¬ing fluid behavior are the provision of a well-drained fill through desliming or classification and the achievement of a small degree of consolidation through the addition of cement in ratios as lean as 40 to 1 (2.4% cement). The acceptance of classified mill tailings as backfill material has been enhanced by its relative economy, including its source, preparation, delivery, and stope distribution. Transportation from the backfill prepara¬tion plant on the surface into the stope usually can be accomplished with low power consumption, with low labor costs, with few capital costs, and at high tonnage rates. An additional benefit is a reduction of the storage volume required for surface disposal of the tailings stream, with a resultant improvement in the environ¬ment. The costs of placing cemented tailings backfill generally range from $1.65 to $6.61/t ($1.50 to $6.00 per st) of fill depending upon the cement ratio used. Scope This chapter examines a major backfill program at a mine and mill complex where the backfill facilities are included as a part of the original planning. The backfill preparation plant is intended to make maximum use of remote controls and automation. The logistics asso¬ciated with material storage, handling, and metering in the plant are outlined. Important considerations in specifying equipment for typical service conditions are discussed. The fill delivery system is described, includ¬ing the boreholes, level lines, and stope distribution lines. Stope preparations for fill confinement and drain¬age are described, as are the techniques of placement and distribution. Methods of controlling and directing the flow of drainage water and slimes are presented, along with the facilities and equipment for clarification, pumping, and sludge removal. As shown in Fig. 1, the fill program encompasses most aspects of the mining and refining facilities, so the discussion is brief in each area. The preparation of backfill of a uniform and con¬trollable quality is presented here as a material handling problem. The balance of the presentation concentrates on the logic of the system, the costs where meaningful (in 1977 US $ unless otherwise specified), and some operating "tricks" that have contributed to system per¬formance and reliability. SURFACE PREPARATION PLANT A backfill preparation plant is required on the surface. This plant generates suitable fill material from the stream of mill tailings. Among the functions of the plant are: 1) Slimes are removed to improve the percolation characteristics of the fill; typically, particles finer than 325 mesh are removed from the tailings. 2) Tailings and sand storages are provided so that the steady stream of tailings produced by the mill can be accepted. Provision is made to accommodate the cyclic high-volume demand from the mine. 3) The plant stores the cement and contains meter¬ing and mixing facilities to provide fill of a controllable and uniform quality. 4) The hydraulic backfill delivery system is a part

Jan 1, 1982

By Yong Tian, Tian Zhang, Zhao-Dong Wang

To meet the requirements of high-performance steel plates, while reducing manufacturing costs and saving energy, the advanced cooling system for plate mill (ADCOS-PM) with functions of accelerated cooling (ACC), ultra-fast cooling (UFC), and direct quenching (DQ) was researched and developed by the State Key Laboratory of Rolling and Automation (RAL). Since 2003, several sets of ADCOS-PM device were developed and implemented in industrial practice. To fully utilize the ADCOS-PM technology, the combination of various strengthening mechanisms was promoted by NG-TMCP technology and low-cost, high performance plates were produced such as pipeline steels, and high-strength construction machinery steel.

Oct 1, 2019

By W. E. Pittman

The Bureau of Mines, as part of its Health and Safety Technology Program, is conducting research on the use of ground penetrating radar (GPR) for mine hazard detection. GPR offers a possibility of mapping immediate below-surface geologic conditions, including faulting and other anomalies, thereby exposing potential safety hazards to miners. This report summarizes a literature review of the current status of GPR research in and outside the Bureau.

Jan 1, 1984

By W. H. Zieman

"THIS IS THE THIRD of the consecutive Annual Forums on Grinding that were instituted by Mr. L. E. Djingheuzian in 1957. The first was on the subject of Ball Milling (Transactions, Volume LX, 1957) and the second on The N on-Cataracting Ball Mill (Trans-actions, Volume LXI, 1958). From the discussions at these forums it was evident that one of the most important factors affecting the efficiency of grinding is the shape of the liners. In order to make a study of liners in use, it was •decided to seek the co-operation of operators across the country by sending out questionnaires requesting basic information. Additionally, these operators were urged to set down briefly any pertinent information on the subject acquired through experience and experiments at their own particular plants. A compilation and analysis of these data were to form a basis for discussion at the Forum on Liners at the Annual Meeting in Montreal, April, 1959. The response of the milling fraternity to this solicitation was most gratifying, and clearly indicated the importance attached by the operators to the effect of liner design upon overall grinding performance."

Jan 1, 1959

By E. Kalhan, C. Kincal

One of the biggest problems in open pit mining is slope stability. The avoidance of slope stability problems depends on a comprehensive assessment of environmental and operational factors such as geology, climate, and mining activities. In the light of these considerations, slope geometries should be determined in accordance with engineering principles. In this research, the slope stability of rock slopes in a mine opened in a gneiss geological unit has been studied. Production activities were ceased in 2019 due to the slope movements in the eastern part of the quarry. In order to safely continue the production, field works were primarily carried out. To assess slope stability, detailed discontinuity surveys were carried out on bench faces. Subsequently, kinematic and numerical analyses were employed to identify geometries that are expected to maintain stability under the prevailing geological structures and environmental constraints. Engineering geological studies such as scanline measurements in steps and investigation of potential failure mechanisms by kinematic analysis technique were carried out. Small module reactor and Q-slope rock mass classification systems were used to evaluate slope stability. Based on these classification systems potential unstable rock slopes were identified and thematic maps were created using geographic information systems. The most suitable slope geometries are suggested for these slopes. In addition, the improvement methods suggested by the rock mass classification systems were proposed for these slopes.

Sep 1, 2025

By R. A. Cattell

With the activities of the Petroleum and Natural Gas Division geared chiefly to problems directly connected with the war effort , the emphasis of the work under oil and gas development and production was to make engineering studies of selected reservoirs for the Petroleum Administration for War , to determine the extractable quantities of components in them, and to study the characteristics of these components for use in the manufacture of aviation gasoline and other products . The needs of the Petroleum Administration for War and the operators for specific data from gas - condensate fields were fulfilled , and , in addition , engineering data along lines of a forward - looking program of research on reservoir behavior were collected , which should be of great value in the postwar period . It is planned to publish many of these data as soon as conditions permit . The work of the Secondary Recovery Section had as its objectives in- . creasing the rate of production of crude petroleum and , which is more important , preventing the premature abandonment of wells in " stripper " and marginal According to the National Survey of Stripper Wells by the National Stripper Well Association in cooperation with the Interstate Oil Compact Commission , a total of 67,460 stripper wells was abandoned from January 1 , 1935 , to July 1 , 1942 , inclusive , with an estimated loss in proved reserves of approximately 216 million barrels . This survey also indicates that over 1.2 billion barrels of oil would be recovered by primary production from more than 290,000 stripper wells then in operation , and an additional 2.5 billion barrels of oil could be recovered from them by secondary production methods . The work of the Chemistry and Refining Section was oriented towards the optimum utilization of crude oils in the manufacture of aviation fuels for spark-ignition and jet - propulsion engines . The work involved intensive studies of superfractionation , hydrocarbon analysis , and the engine testing of fuels . Particular attention was given to the effect of sulfur compounds in the crude oils and in the fuels made from them . The research on thermodynamics is concerned with the experimental determination of precise and accurate values of the fundamental thermodynamic constants of pure hydrocarbons and related compounds . The data obtained in these investigations will be utilized for devising and improving chemical processes in which petroleum hydrocarbons are the raw materials . Without such data , much time and expensive material and equipment may be wasted in attempts to obtain reactions under conditions that the laws of thermodynamics rule out of consideration . Thermodynamic data are useful and required in the petroleum industry for calculations of heat balances in the design of furnaces , fractionating towers , and heat- transfer equipment . It is of utmost importance , also , to know the heat requirements of cracking and other chemical reactions so that heat may be supplied or dissipated in the proper proportions . These needs for thermodynamic data are being recognized more and more by petroleum -refining engineers . The responsibility for the production of helium for the Navy , the Army , other governmental agencies and non-Federal users is vested in the Bureau of Mines by an Act of Congress ( 50 Stat . 885 ; 50 U.S.c. 161-166 ) . The Helium Subdivision of the Petroleum and Natural Gas Division continued to meet all demands for helium .

Jun 1, 1949

By R. E. Siemens

The Bureau of Mines sought to correlate the variation of structure-sensitive superconducting properties with microstructure in selected Cb-Hf alloys and to compare the experimental results with those predicted by the GLAG theory. Alloys in wire and rod form were evaluated by critical temperature, critical current, magnetization, resistivity measurements, and optical and electron microscopy. In the absence of an external magnetic field, the current carrying capacity of columbium was greatly reduced with addition of up to 85 wt pct Hf, but a large increase in Ic occurred for Cb-90 wt pct Hf. Favorable Ic-H behavior was observed in cold-drawn alloys containing 25 and 57 wt pct Hf. Correspondingly, a maximum in Tc occurred at 10-25 and 90 wt pct Hf. Four- or five-hour heat treatment at 600° C resulted in maximum Ic values and maximum hysteresis in magnetization. Dislocation pileup, polygonization, and fine precipitates, responsible for flux pinning, are listed in order of their effectiveness as pinning sites. Sites having an average separation of 1,500 to 3,000 A and a diameter of 1,000 A or less were most effective in influencing Ic-H and M-H behavior. The resistive critical fields increased smoothly to a maximum of 80 k0e between 60 and 65 wt pct Hf. Highfield, mixed state, reversible paramagnetism was observed in some alloys; however, the GLAG theory was in good agreement with experimental results for the majority of the composition range studied.

Jan 1, 1969

By J. H. East, D. Harrington

"INTRODUCTION Mining at its best is not a clean occupation for either surface or underground employees; and this applies alike to coal, metal, and non-metallic mines. The employees are handling minerals that have been blasted, or broken by some means and are subjected to mineral dust, whether it is coal, quartz, or talc. The employees usually wear clothes specifically adapted to the work in which they are engaged, and frequently these clothes are not suitable for use away from the mine. Many mines are wet, and employees must wear rubber boots to remain at least partly dry, and even on relatively dry mines, some parts of the mines usually have water falling from overhead, there are accumulations of water, or the floor or other surfaces are wet or muddy, Some mines are dusty, and the air-borne dust quickly settles on the clothes and body of the miner, especially, when he is working in confined areas, or in places that are hot, humid, or poorly ventilated. Most occupations around a coal tipple, anthracite breaker, or a mill at a metal or nonmetallic mine have their own problems of cleanliness as to skin or clothes or both. Mining in any of its phases is inherently dirty work, and the employees dress accordingly while at work.In the early stages of mining it was the custom or workers to wear their dirty clothes home and change there. This necessitated their going home after work in dirty clothes which were usually damp from perspiration or from contact with wet or muddy matelials or surfaces, and, in addition to being inconvenient this was a frequent cause of colds, pneumonia, other pulmonary diseases or, possible skin ailments. Men working in very wet mines found that it was more satisfactory to change into dry clothes in the boiler room at the mine after work and allow their wet clothes to dry overnight. The mining companies later provided the first of the so-called ""dry-houses"" which were heated but had, few, if any, conveniences, such as showers, lockers, or latrines. The miners changed into dry clothes after work, but would not bathe or ""clean up"" until they reached their homes. Later, progressive mining companies provided bathing facilities for the employees, and eventually the present modern wash and change houses were evolved. Unfortunately, many mines, still have no bathing accommodations, and many have only makeshift accommodations."

Dec 1, 1947

By Ronald H. Church

The Bureau of Mines tested & ground penetrating radar (GPR) system in the central Florida phosphate district. to determine the feasibility of utilizing GPR technology for subsurface cavity detection. The test area is located in karst topography where sinkhole development is prevalent. State regulations require subsurface drilling of damsites to identify underground anomalies; however, this method is not totally accurate in locating subsurface cavities that could lead to sinkhole development. An electromagnetic method of identifying anoma-lous subsurface conditions could reduce or eliminate the possibility of dam failure due to sinkhole development. The Bureau devised a GPR system that successfully penetrated over 50 ft of overburden and gave recognizable radar return signals characteristic of a rock-cavity interface.

Jan 1, 1986

Column flotation cells continue to gain acceptance in the coal industry for the treatment of high-ash streams containing clay slimes. Unfortunately, some industrial installations have failed to meet expectations due to improper scale-up, incorrect operation and poor ancillary circuit design. To overcome these problems, case studies have been conducted to fully define the capabilities of column cells for coal applications. These data have been used to develop generic engineering guidelines for column circuit design and operation. An economic analysis has also been conducted to illustrate the importance of key capital cost considerations. These analyses indicate that column cells are significantly more expensive than conventional machines, although this difference can be greatly reduced through the installation of very large-diameter columns.

Jan 1, 1999

By K. S. Radcliffe

Results are presented for the first phase of an experimental program to study the feasibility of using acoustic velocity for predicting the state of stress in a rock mass. Compressional wave velocities were determined axially in cylindrical samples during uniaxial compression for several rock types conditioned in dry and water-saturated environments. Results indicate that in rocks containing compressible voids or cracks, substantial velocity change occurs with the application of stress in the lower (below 100 MPa) stress regime. The effect norm- ally is nonlinear, however, and diminishes to asymptotic values when cracks or voids become closed or with saturation. Empirical prediction equations were derived for each rock type by linear and nonlinear regression analyses, and correlation coefficients were calculated to determine the equations that best fit the stress- velocity data. The operational range for predicting stress using compressional-wave velocity appears to be within the range of vertical stress expected in most shallow to intermediate depth mining operations (less than 1,000 m). Based on the experimental results to date and theoretical considerations, it appears that the technology can be advanced to predict in situ stress based on acoustic P-wave velocity determinations in most mining situations.

Jan 1, 1986

By I. Haskett

ABSTRACT The Redwater pool, in north-central Alberta, was discovered in October, 1948, and at the end of 1950 was about 85 per cent developed. Production is from a Devonian coral limestone reef and is found at an average depth of 3,150 feet. The pool has an estimated .productive area of 37,000 acres, and a maximum oil zone thickness of slightly over 200 feet. Wide variations exist in both type and values of porosity, with the average value determined for the reservoir being 6.16 per cent. The total stock tank oil in place is about 1.24 billion barrels. The crude has a saturation pressure of 485 psig, com-pared to the original value of 1,050 psig for the reservoir, and the principal recovery mechanism so far has been the natural water drive. Cumulative production to January 1st, 1951, has been about 15.5 million barrels. These withdrawals resulted in a reservoir pressure decline of slightly over 100 psi. Predictions of future behaviour indicate that the water drive will not be of sufficient magnitude to maintain the reservoir above saturation pressure past 1953, and that, with natural depletion, the pool will be produced largely by a solution gas drive. Pressure maintenance by water injection has been considered and the possibility of raising the pressure to the original value of 1,050 psig is also discussed. INTRODUCTION WITH the discovery of the Lewduc pool, early in 1947, the Devonian limestone became the major geological formation contributing to Western Canada's rapidly growing petroleum reserves. Redwater, discovered in October, 1948, is now the largest known Devonian pool in Canada, with a recoverable reserve estimated at approximately 500 million barrels. Until recent years, the knowledge of the nature and characteristics of this type of limestone reservoir has been comparatively limited.

Jan 1, 1951

By G. G. Eichholz

SUMMARY RADIOACTIVE dynamite has been prepared by introducing a small amount of antimony-124 into the explosive. Test work is described on the effectiveness of this tracer, on radiation levels in its neighbourhood, and on different methods of .application. Factors determining the choice of isotope, amount of activity, and overall cost of this process are discussed. INTRODUCTION Instances are known in which dynamite remains unexploded in drill holes in mining operations. Usually such 'bootlegs' are easily located by inspection of the face and the powder is removed before subsequent drilling is started. Occasionally, however, serious accidents occur because workmen drill into an undetected piece of dynamite. In order to avoid such accidents it was suggested that a different method of location might be tied, such as that afforded by the use of radioactive tracers. This paper describes some experiments that were carried out under the auspices of the Department of Mines and Technical Surveys, with the active co-operation of Canadian Industries Ltd. and Canadian Refractories Ltd., to test the feasibility of such a scheme.

Jan 1, 1957

By E Garbarino, P Molina, V Badino

Given the ever increasing quantity of construction and demolition waste (C&DW), one of the most challenging issues presently facing policymakers and public administrators in Italy concerns how to organise and manage collection and recycling and to understand whether and to what extent recycled aggregate can complement natural building aggregates in a sustainable supply mix (SSM). The paper presents the results of a research aimed at analysing energy and environmental implications of the C&DW recycling chain in the administrative territory of Provincia di Torino in northern Italy. In respect of a population of about 2.25 million inhabitants, the annual production of C&DW in the area under study is 1.8 Mt. A combined geographical information system (GIS) and Life Cycle Assessment (LCA) model was developed, paying attention to the geographical location, land use, transportation network and avoided landfill: crucial issues for sustainable planning and management. Around 90 recycling plants were classified according to the size, typology (stationary, semi-mobile and mobile) and physical- mechanical characteristics of the recycled aggregate. Under different assumptions relevant to the delivery distance, and considering the typology and grade of recycled aggregate, as well as local availability of natural aggregates, it was possible to evaluate the geographical coverage of aggregates demand and to use LCA in order to identify and quantify energy and environmental indicators.

Jan 1, 2009

By DeVerle P. Harris, David E. Euresty

"Potential metal supply refers to metals to be produced from as yet unknown deposits. Naturally, to measure potential supply requires, among other things, inference to the number of deposits, their tonnage, and their grade Thus, probability distributions were constructed for each 400-square mile cell in Northern Sonora, Mexico. A computer system was developed that simulated the occurrence of deposits for each cell, exploration for the deposits, and their exploitation. Evaluation was performed for each deposit by discounted cash flow analysis.An objective of this study was to explore the effect of the transportation network and required road or railroad construction upon potential supply. Consequently, the evaluation system was designed to consider the spatial location of a simulated deposit to the existing transportation network and the market destination. The construction of linkages to connect the deposit to existing transportation arteries as well as the carrying of the concentrates to the intended market were simulated. in terms of cost. The selection of the path took into account the existing terrain. This was done by digitizing topographical maps and representing the topography of the area by an orthogonal grid of elevations. The optimum route was selected by dynamic programming, meeting a prescribed gradient constraint. The potential supply of each cell was determined, allowing for the infrastructure effect."

Jan 1, 2014

By Peter B. Knuckey

1, Introduction Location Kalengwa mine is located in the North Western Province of Zambia, 402 kilometre by unpaved road to the west of Kitwe, which is roughly in the centre of the Zambian Copperbelt, well known as one of the world's centres of copper mining. Its position is illustrated on the map of Africa in Figure 1 and on the map of Zambia in Figure 2. It is a mine of Roan Consolidated Mines Limited whose other properties, Mufulira, Luanshya, Chambishi and Chibuluma Mines, are all located on the Copperbelt. It is managed by the Chibuluma Division of the company. The rate of production from Kalengwa will vary from 12 000 to 17 000 tonnes of saleable copper a year over the next six years. Kalengwa did not exist as a place until the first prospecting parties and later the mine became established and the early working population was recruited entirely from small villages in the surrounding area as much as thirty miles away. The mining area consists of fourteen mining locations amounting to 3.35 square kilometres and the land may be used for any purpose connected with mining, including housing, wood cutting and other utilities. The whole area is, except for minor undulations, a fairly flat plateau with main rivers running from north to south and flood basins known as "dambos" located in a general east west direction. Vegetation is, with the exception of the grassy dambos, temperate forest with relatively light undergrowth. Game of great variety is prolific, as is the associated tsetse fly.

Jan 1, 1971