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By William A. Hustrulid

The subject of surface mine development is large. This section covers the fundamental concepts involved in both the open pit mining of thick or steeply dipping deposits as well as the strip mining of thin, shallow, and relatively flat-lying seams or beds. Design involves the marrying of geometries, ore and waste characteristics, equipment, and economics so that the desired result is achieved. Generally, there are many possible combinations from which to choose. For example, extraction over a short time period requires one strategy while quite another is applied for longer times. Variations in supply and demand require some flexibility of operation. Customer requirements impose certain constraints regarding the set of possible designs. Over recent years, planning and operating considerations for surface mining imposed by environmental requirements have increased markedly. There have, at the same time, been enormous advances made in the design aids available to the mine planner. Computer simulation of the various options, whether it be for mine design or equipment selection, provides detailed information for decision making in real time. A significant challenge to the engineer/planner is how to best use the aids avail-able. Because of the widespread use of commercially available and in-house computer software by industry, this section does not deal with the details of planning (for basic coverage of mine development, see Section 7). Rather, some of the basic concepts are stressed. The principles involved in equipment sizing and selection are discussed. A highly important but sometimes over-looked aspect of planning, haul road design, is also covered. For surface mining operations of the future, in-pit crushing and conveying will become even more important. Some of the considerations for application evaluation are included. The section concludes with some future concepts for surface mining.

Jan 1, 2008

By J. Thompson

Paper written on project work carried out in partial fulfilment of B. Eng (Mining Engineering) degree A study into the stability of strike gullies at TauTona mine was to be carried out. In reaching the conclusions to follow, a three-stage process was followed. ?A literature study as well as discussions with management and workers alike to gain their inputs and perceptions. ?An ESH Department survey into the history of transgression from proper mine standard in TauTona strike gullies. Unfortunately records were found to be scarce and obscure and the importance of better inter-departmental recordings cannot be stressed enough. ?An underground survey of 11 pre-selected gullies distributed in both the UCL and LCL reef horizons. This stage is to carry the greatest weight in the points to be brought forward in this report. The process highlighted and ranked the following areas as the most critical role players in the deterioration of strike gullies: ?Poor blasting practice ?Sub-standard siding depth and lead-lags ?Split sets ?Off line gully development ?Adverse geological features. The following has been suggested to the mine to help reduce strike gully instability. ?Where possible, maintain lead-lags below 7 m?else increase the siding depth to suit. ?Decrease the gully width standard to 1.2 m (especially in ?high risk areas?). ?Discourage drillers from drilling side holes in gully face blast pattern. This will allow for time in which tendon support can be kept up to date. ?Ensure split sets are installed 1 m behind the gully face so as to prevent opening up of fractures. ?Utilize the centre split set in the 1:2:1 pattern to maintain the proper gully line. ?When adverse conditions prevail, it is necessary to apply a special support plan not only to the panel face, but also (just as importantly) to the gully as well. Shotcreting of the gully hanging is a suitable long-term consideration for providing the additional a real coverage needed. List of Abbreviations [CL Carbon Leader M/O Mine Overseer UCL Upper Carbon Leader FOG Fall of Ground LCL Lower Carbon Leader H/W Hanging Wall ERR Energy Release Rate F/W Foot Wall WDL Western Deep Levels ESH Environmental Safety and Health ]

Jan 1, 2002

By R. G. Zaripova, N. D. Ryan, H. J. McQueen

The austenitic and ferritic stainless steels do not undergo any phase transformation that induces very fine grains in the product through thermomechanical processing as practiced in most other steels. Considerable grain refinement can be achieved by intense multistage deformation descending through warm to cold working; notably multi-axial forging of bulk material can attain high strains with diminished risk of cracking. Hot working to improve ductility yields finer grain sizes as the T is reduced and strain rate E raised; increased strain has limited effect due to the steady state regime. Ferritic steels develop subgrains with size diminishing as E rises and T falls with the advantage of retained strain hardening; recrystallization delivers grains several times the cell size. In austenitic steels, dynamic recrystallization (DRX) provides finer grains at higher E and lower T with a lower limit due to intergranular cracking. The DRX grains contain a strengthening substructure that can easily be retained by quenching; if static recrystallization is allowed to occur the grain size rises markedly. Multistage rolling with diminishing T is able to provide grain refinement to the same degree as straining at the finishing T yet provides better ductility. grains on recrystallization. As a result of the strain induced transformation to martensite, small subzero deformations of austenitic or duplex steels produce very high dislocation densities that yield marked grain refinement when they revert upon reheating.

Jan 1, 2004

By A Buckley

Many policy issues facing the mining industry and affected communities are at a level of complexity that they can be called ‘wicked’ problems. The term ‘wicked’ in this context is used, not in the sense of iniquity, but rather as social and economic issues highly resistant to resolution. For the resource extraction sector and affected communities there are an array of challenges embedded in the industry’s production and profit paradigm, the remoteness of mineral reserves and affected communities’ expectations of economic benefit and a positive legacy. The mining industry as a whole is dominated by economic, political, legislative and market structures that influence and constrain interactions between mine operations and local communities. For communities, with particular reference to regional Western Australia, intractable problems include the uncertainty of, yet increasing dependence on, a mining economy. Questionable outcomes for local communities include the limited realisation of local employment and business development benefits, and low overall outcomes or low multiplier effects. ‘Wicked’ problems, according to the literature, are best addressed via collaboration. In the mid-west region of WA, with mining and infrastructure construction underway, alliances have formed between mining companies, the major port and rail infrastructure project (Oakajee Port and Rail) and regional and local governance stakeholders. The major impetus for these affiliations is to expedite planning and associated infrastructure development taking into account the lessons from other mineral-led regions. What has resulted is an array of innovative approaches to stubborn problems including planning well in advance of full-scale mining; regionally coordinated procurement; ‘mine ready’ local businesses; and strategic investments in social infrastructure; including community trust funds paid in advance of project delivery. This paper examines these innovative approaches/alliances and assesses their effectiveness in addressing long standing mining/community dilemmas.

Nov 22, 2011

By Shijie Wang

Lifetime achievements of Professor Reddy ’s teaching, research and scholarship in the field of chemical and materials science and engineering are briefly described. He has devoted his entire career in the introduction and application of process engineering principles to the quantitative description of materials processing reactions, and industrial operations. He has formulated quantitative methodologies based on first principles of thermodynamics, phase equilibria and kinetics to: design of slags and fluxes for production and purification of metals and alloys; development of Reddy-Blander model for a priori prediction of impurities capacities of melts; development of novel ionic liquid electrolytes for materials processing; development of new theories for alloys and molten salts; design materials for fuel cells and capacitors; use of thermodynamic approaches to predict physical properties of materials; industrial energy waste separation and remediation; and thermal energy storage. He is a scholar and mentor, and has made numerous scientific and service contributions to the society and metallurgical and materials engineering education.

Mar 1, 2017

By E. D. Gardner

Ore and concentrate are transported on, the surface at western mining districts by (1) railroads, (2) surface trams, (3) aerial trams, (4) trucks, and (5) wagons, and (6) on the backs of animals. The daily and ultimate tonnage to be moved is the principal factor governing the selection of the method of transportation. Railroads are preferred when large tonnages are to be hauled over relatively long distances. The mine-haulage system may be extended or surface trams built to the mill or shipping point if a practical track grade is possible and if the distance is relatively short. Aerial trams have a special field of usefulness for transportation over steep or excessively rough terrain.

Jan 1, 1936

By V. Rajagopal

Corrosion and abrasion properties of a series of chromium-containing cast iron balls with Cr contents ranging from 0 to 29% was evaluated and compared with austenitic stainless steel and mild steel balls. Marked ball wear tests were performed on artificial ore samples consisting of 95% quartzite with either 5% pyrrhotite or 5% chalcopyrite under a nitrogen or oxygen atmosphere. The electrochemical mechanism was investigated by correlating the corrosive wear with the corrosion currents obtained from potentiodynamic polarization curves under abrasion. An offset in their electrochemical activities was observed somewhere between 16 and 26% Cr. In fact, 26 and 29% Cr cast irons showed an excellent corrosion resistance approaching that of austenitic stainless steel. Flotation recoveries were estimated on a 95% quartzite + 5% pyrrhotite sample ground with various cast iron ball materials under an oxygen or nitrogen atmosphere. Electrochemical results are found to be in good agreement with corrosive wear obtained from marked ball wear test and with flotation results.

Jan 1, 1991

By David L. Hill

Newmont Gold Company's Mill No. 4 is located along the Carlin trend, about 25 miles North of Carlin, Nevada. The plant consists of a primary grinding circuit using a 7.2 m (22 ft) diameter by 2.6 m (8 ft) long semi-autogenous mill along with a 2.3 m (7 ft) diameter cone crusher. Secondary grinding is performed in a 4.8 m (14.5 ft) diameter by 9.2 m (28 ft) long overflow ball mill in closed circuit with a set of 66 cm (26 in) diameter cyclones. The ground product is fed to a typical carbon-in-leach gold leach circuit. The grinding/crushing circuit operation and control scheme are the topics of this paper.

Jan 1, 1993

By W. L. EGY, GEORGES. RICE, L. M. JONES, J. K. CLEMENT

This report has been prepared, not only for the purpose of recording the results of the first series of coal-dust tests conducted in the experimental mine of the Bureau of Mines, but also to place before the mining public a description of the mine and an account of the objects sought in its establishment. Soon after the organization of the technologic branch of the United States Geological Survey, J. A. Holmes, then chief of the branch, concluded that for the solution of various problems relating to the causes and prevention of mine explosions it would be best to carry on large-scale tests in a mine rather than in a surface gallery. The idea of utilizing the underground passage of a mine for making explosion experiments did not at' first meet with general approval among investigators in this country or abroad. Many thought a mine passage was not a proper place in which scientific tests could be conducted, as great difficulty in controlling conditions was expected. However, after all arguments for and against such an investigation had been carefully considered, plans for opening an experimental mine were definitely adopted by the Bureau of Mines in 1910, and an allotment of funds was made to carry out the project. The first endeavor was to find an existing mine suitable for the purpose, but the mines offered by owners were either worked out, were wet, had poor roofs, or presented complications of various kinds, so that it was finally decided to open a mine if a site could be obtained having natural conditions that would fill the various requirements. A most desirable location was found on property of the Pittsburgh Coal Co., near Bruceton, Pa. The president of this company, Mr. W. K. Field, the general manager, Mr. G. W. Schluederberg, and the chief engineer, Mr. E. J. Taylor, rendered every possible service in

Jan 1, 1913

By J. J. Jakosky

THE method of electrical mapping of oil structures to be described possesses certain limitations, as well as certain definite advantages. It, in common with other geophysical methods, is not a panacea for the solution of all subsurface geological problems. It operates on differences in electrical conductivity of the geological strata, whereas the other most-used methods operate on (1) differences in magnetic properties, (2) differences in gravimetric properties, or (3) differences in seismic properties. This modification of the resistivity method is therefore able to obtain subsurface information under conditions not favorable to the other methods mentioned. Where the other methods have been employed with ambiguous results it may act as a complementary method.

Jan 1, 1936

By R. C. D. Phillis

The annual mine planning process is one of the most important tactical/operational steps towards achieving strategic goals. These tactical plans are part of a very comprehensive Mineral Resource Management process, with the natural sequel to planning being execution. The execution of an underground hard rock mine plan is a multi-project environment that comprises many development-construction-equipping-stoping single project paths, which are referred to as ?stoping paths?. The uncertainty that typifies execution of projects comes in the form of untimely disruptions to constituent tasks and/or project paths. Annual mining plans also include quantified objectives for occupational health and safety, production, quality, cost, employee morale, environment, and corporate social investment. Such objectives make for a highly complex environment that management must contend with?complex in the sense that all the paths and objectives have interdependent constraints. Furthermore, at the time of this paper, Sections54*and 55**of the MHSA*** put the onus on management to ensure legislative adherence. It stands to reason that planning estimates allow excess capacity?buffers?that cushions the impact of untimely disruptions. This paper concerns the fact that despite all the buffers allowed for, time, scope, and budget creeps impact on mine planning and threaten its successful execution. As a consequence, the paper deals with buffer management, the essence of Critical Chain Project Management (CCPM). Effective buffer management provided strategic (executive level) updates without losing the tactical/operational detail necessary for job card creation, especially where professional skills and experience are in short supply. Indicative bottom-line results showed CCPM to be highly effective.

Jan 1, 2011

Arsenic.--Inorganic arsenic has been added to the Environmental Protection Agency's list of hazardous air pollutants because of a high probability it can cause cancer. EPA estimates that inorganic arsenic emissions into ambient air total more than 6,000 tons per year, with about 65;L of this coming from the operations of copper, lead, and zinc smelters. Asbestos Detection.--In June 14, the President signed S. 1658 providing $172.5 million to detect and remove asbestos hazards in schools. Asbestos Use Must be Reported.--All firms using asbestos in the manufacture of some 30 categories of products must describe in detail how they use the mineral to the Consumer Product Safety Commission, for all manufactures since January 1, 1977.

Jan 1, 1980

By Marcello M. Veiga

Informal gold mining operations in the Amazon emit about 100 tonnes of mercury annually because of poor amalgamation practice. Lack of information and the complexity of mercury transformations hinder effective action to prevent such pollution and/or monitor its extent. In the past, mathematical equations have been formulated to deal with the correlation of natural variables and mercury in biota but often, the error range is too great to provide useful models. Projection of physico-chemical variations in an environment subjected to mercury emissions onto the extent of bioaccumulation is fraught with many uncertainties and unknowns such as internal correlations between variables and the site-specific nature of biota contamination. Often assumptions about closed systems are invalid when applied to natural environments. This work presents a heuristic approach to this problem in which amalgamation methods and natural variables are dealt with using an IF-THEN rule-based system that concludes about levels of emission and risk of bioaccumulation. The system is able to handle uncertain or vague data and yet still provide useful output. Belief in mercury oxidation or dangerous conditions are examined using Fuzzy Logic techniques and Inference Equations. These belief levels are derived from thermodynamic equilibrium data together with field observations of natural variables. This procedure can reduce the need for sophisticated analytical equipment and can provide information and diagnosis to non-technical people.

Jan 1, 1994

By W. H. Ryback

When a fire or explosion occurs in an underground coal mine, the atmosphere guickly becomes irrespirable. Highly irritant smoke and toxic levels of carbon monoxide and dioxide are produced, and consumption of oxygen by the fire or blast can reduce its concentration below that needed to support life. Work parties entering such a hazardous atmosphere for rescue or recovery operations are required to use, as their primary respiratory protection, a fully self-contained breathing apparatus of at least two hours duration. Apparatus used in this role has primarily been of the closed circuit rebreather type, using pressurized oxygen storage and chemical removal of expired carbon dioxide. Typically, commercial self-contained breathing devices for mine rescue have been heavy, bulky, and uncomfortable to use. The McCaa apparatus, long the industry standard, represented the best art available when it was First designed in 1926. It weighs 41 Ibs., protrudes about six inches above shoulder height, and provides breathing gas at temperatures up to 120° F. More recent designs, such as the Drager BG174A and Scott Rescue-Pak, using modern light weight materials and fabrication techniques have improved on all parameters of the McCaa to some extent. It was the intent of the Bureau of Mines, acting under the authority of the Coal Mine Health and Safety Act of 1969, to fund the development of a new self-contained breathing apparatus which would incorporate the best available technology and serve as a benchmark for future commercial designs, as the Bureau-sponsored McCaa had 45 years previously.

Jan 1, 1974

By Joseph J. Feiler

Fires in underground coal mines are persistent problems anywhere in the world that coal is mined. Coal fires pose safety and health hazards in the form of mine subsidence, loss of energy reserves, destruction of property and surface improvements, and air pollution. In 1995, the US Bureau of Mines (US-BM), in cooperation with the Colorado Division of Minerals and Geology (CDMG),entered into a contract with Goodson & Associates Inc. (GAI) to design and field test the effectiveness of a new foamed grout technology called ThermoCell. GAI is a Lakewood, CO geotechnical and mining reclamation engineering firm. The company developed ThermoCell to control and extinguish underground coal fires. The viability of the special grout and the technology of application were established during a full-scale field demonstration at the abandoned IHI Coal Mine fire, near Rifle, CO. Following acquisition of additional funding by CDMG in 1999, Goodson returned to the site in April to continue the grouting to fully extinguish the IHI fire.

Jan 1, 2000

By R. L. Brown

The Buchans mining district is located roughly at the center of the island of Newfoundland and contains some 18 separate mineral deposits. The first of these deposits was discovered in 1905, the latest discovery having been made in 1979. To the present (1983), some 16 Mt (17.7 million st) grading 1.33% Cu, 7.5% Pb, 14.5% Zn, 115 g/ t (3.7 oz per ton) Ag, and 1.4 g/t (0.04 oz per ton) Au have been mined. Mining operations are now largely terminated, but a few hundred thousand tons of economically marginal reserves may be mined in a salvage operation. The Geological Association of Canada Special Paper No. 22, "The Buchans Orebodies, 50 years of Mining and Exploration," contains papers which describe the history, geology, and the application of evolving geological concepts in exploration. Papers by Neary, Swanson, and Thurlow and Swanson in that volume are topical to the present discussion. Successful exploration techniques at Buchans included physical prospecting, utilization of the state-of-the-art geophysical techniques, saturation diamond drilling which was made possible by the high gross value of the existing ore, and, since 1955, diamond drilling directed by fairly well understood geological parameters. The record of discovery started in 1905 when the Buchans River deposit was found by Matty Mitchell, a prospector employed by the Anglo- Newfoundland Development Co., a British company which owned mineral rights over a very large area in the Red Indian Lake-Exploits River drainage system.

Jan 1, 1991

By OÆBrien R. T

A small static bed was used to study the thermal cycles required for the heat hardening of pellets based on synthetic magnetite concentrates and a naturally fine hematite. This apparatus can be employed to yield broad process data for the design of a recuperative strand system operating on the magnetite concentrates.Various alternatives are given for a process to heat harden the hematite ore but a preference is given to the production of a self fluxing pellet. Bond types and general mineralogical structures are interpreted against the optimum firing cycle necessary to produce a defined quality of pellet.INTRODUCTIONThe work reported in this paper extends that on the "Heat Hardening of Artificial Magnetite Pellets", which was described at the International Symposium on Agglomeration, sponsored by the American Institute of Mining, Metallurgical and Petroleum Engineers at Philadelphia, U.S.A. in April 1961. Whereas that work was of a more basic nature, serving to illustrate the suitability of artificial magnetites with various admixtures, to the application of heat hardened pellets, on this occasion the aim is to illustrate the procedures which were used to establish the dimensions of commercial recuperative strands for Australian raw materials.The nature of the pellet feed, Le. relatively uniform spheres of + i in.-Yi6 in. diameter, makes it possible to use small scale static pots for test work. By the use of a closed system and the measurement of suctions, gas flows...

Jan 1, 1963

By R. W. Raymond

On the Manchuria. SOMEWHAT fatigued with excess of enjoyment and strenuous continuity of movement on the trip to and through California, the members and guests of the Institute party embarked Tuesday, Oct. 17, on the Pacific Mail S. S. Manchuria for a further journey to and through Japan. The good ship displayed the flag of the Institute (blue cross-hammers on a white ground), together with the Stars and Stripes and the ensign of the company. Uninterrupted fair weather and smooth water attended the passage to Honolulu. The Manchuria proved herself most commodious, comfortable and clean ("A sweeter steamship never sailed," quoth President Hunt) ; Captain Dixon and his officers were most agreeable, as well as most efficient; the passenger list comprised many congenial people besides ourselves-among them a score of missionary folk, and also Mr. M. H. de Young, Vice-President of the Panama

Jan 1, 1912

By J. A. Jr. Carpenter

Expanding world economic prosperity, probable peaking of conventional petroleum production in the coming decades and environmental concerns require efforts to increase the efficiency of, and the development of alternatives to, petroleum-based fuels used in automotive transportation. In January 2002, the U.S. Department of Energy (USDOE) and the U.S. Council for Automotive Research (USCAR) of the "Big Three" traditionally-USA-based automakers, DaimlerChrysler, Ford and General Motors, formed the Freedom Cooperative Automotive Research (FreedomCAR) Partnership to fund high-risk, high-payoff research into advanced automotive technologies with the potential for eventually lowering the USA's nearly complete (95%) dependence on petroleum, 55% imported, for its transportation fuels. FreedomCAR replaced the Partnership for a New Generation of Vehicles (PNGV) which existed from 1993 to 2001. In January 2003, the energy-supply industry joined with the FreedomCAR Partnership forming the FreedomCAR and Fuel Initiative (FC&FI) to develop the technologies needed for the mass production of fuel-cell vehicles using hydrogen as fuel and the infrastructure needed to deliver the hydrogen to the consumer. The goal is to enable the automotive and energy-supply industries to make commercialization decisions in 2015 on large-scale introduction of such vehicles and on developing the infrastructure beginning in 2020. In addition to work on fuel cells and hydrogen infrastructure, the FC&FI conducts research on technologies with the potential for nearer-term energy efficiency and environmental benefits, such as new engine concepts, lightweight materials, and engine-electric hybrid propulsion systems. Lightweighting is seen as crucial for shorter and for longer term benefits because hybrid and fuel-cell powertrains are expected, at least in the early stages of adoption, to be heavier and more costly per unit of power than the standard internal-combustion, gasoline- or diesel-fueled powertrains they replace. Research and development (R&D) on casting of aluminum automotive components were major parts of the PNGV and R&D on casting of magnesium automotive components have been and are so under FreedomCAR. This presentation will review those efforts.

Jan 1, 2006

By H. W. Busch

In the course of examinations by representatives of the Bureau of Mines of several compressed-air systems in which explosions had occurred, samples were obtained of the carbon deposits that are formed normally in various parts of the systems by decomposition of the compressor lubricating oil. Experimentation with these carbon deposits has demonstrated that they contain a "carbon-oxygen complex" similar to that formed on coal and on other carbonaceous materials and generally recognized as being the cause of spontaneous heating of coal. The exothermic properties exhibited by such a complex are considered significant in relation to the possible initiation of combustion reactions that may lead to explosions or formation of carbon monoxide in compressed-air systems. This report discusses the occurrence of explosions and formation of carbon monoxide in the use of compressed air and presents results of experimentation conducted with carbon deposits from air compressors.

Jan 1, 1949