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By R. C. de Lange

An improved replica technique is developed for a nondestructive study of the nucleation and growth of fatigue cracks. Three different growth stages of a fatigue crack were observed. An initial stage of high growth rate is followed by a long period of very slow growth, until finally a third period of high growth rate leads to fracture. THE metal-fatigue process is of a very complex nature. The experimental approach towards fatigue is susceptible to many minor influences which, together with the unavoidable scatter in testing results, makes the interpretation a matter of extreme care. The generally accepted fact that, in a homogeneous material, the fatigue cracks start at a free surface indicates that surface studies may contri-but in an essential way to a better understanding of the fatigue mechanisms. Indeed metallographic observations of the fatigue phenomena have been very fruitful in the last decade. The study of extrusions, intrusions, and persistent slip bands has contributed much to the present knowledge of the early processes in fatigue.' The drawback of the current metallographic techniques lies in the fact, however, that either observations of fatigue phenomena had to be made in a destructive way after an only partly executed test or a sequence of observations on the same test bar was only possible on notched specimens.2 4 In both cases an uncertainty exists as to the nucleation and growth of the fatigue crack in an unnotched test bar, where the crack can start at any place of a large area and develops in a test bar, which is macroscopically

Jan 1, 1964

By Roshan B. Bhappu

This is the Centennial year of AIME and many of us reading this issue of ' will be getting ready to attend the Centennial Celebration in New York from February 26 through March 4. The officers of the Division sincerely hope that a large number of our members will attend the fine technical sessions and social functions arranged for this really big meeting. The year 1971 will be a crucial one for MBD. This SME Division is a working group organized "to furnish a medium of cooperation among those interested in the basic unit processes and unit operations of minerals beneficiation; and to promote the advancement of this branch of mineral technology through meetings for professional intercourse, and to stimulate the preparation, reading discussion and circulation of papers connected therewith." No one can deny the worthiness of these objectives or minimize the efforts that Division officers and members have made to attain them. Much has been done over the past several years to achieve a smooth-running and effective MBD organization. However, there is still room for improvement and much more needs to be done in order to provide the best possible services for the membership and the profession.

Jan 1, 1971

By E. O. T. Simpson

"IntroductionAS COMPARED with coal mines in the United States, and even with some of those in eastern Canada, the coal mines of western Canada, generally speaking, :have made little progress toward mechanization at the working faces. So far as Vancouver island is concerned, there are three main reasons for this : ( 1 ) in some areas, conditions• easy for hand-loading but unsuitable for mechanical loading make high outputs per man •possible by the former method; (2) faulting of the coal seams in ..some areas precludes long-term planning and the introduction and efficient use of expensive equipment; (3) thinness •and other characteristics of the seams in many areas favour hand-loading.No. 8 MINENo. 8 mine of Canadian Collieries (Dunsmuir), Limited, is located in the Cumberland sub-area of the Comox coalfield on Vancouver island about 90 miles west-northwest of Vancouver. The geological structure of this coalfield has been described by J. D. McKenzie. The seams occur in the Comox formation, a subdivision of the Upper Cretaceous Nanaimo Group. The formation is of near-shore origin and was laid down on an irregular surface of' older rocks. The irregular generally have a northeasterly dip, modified by gentile folds and by a •few large, and a number of smaller, faults.Four seams have been worked in the Cumberland area and all vary in thickness and in the amount and number of interstratified bone and rock •bands."

Jan 1, 1953

By D. R. Tesarik, T. C. Trancynger, W. G. Pariseau

The Davis detector cavern was excavated on the 4850 Level of the former Homestake Mine in the mid- 1960s to house a novel neutrino detector developed by Nobel Prize winner Dr. R. Davis. The original cavern was about 9.1 x 16.8 x 9.7 m high, excavated in a Precambrian amphibolite known as the Yates unit and enlarged in 2010. In 2009, the National Science Foundation selected the site for development as a national Deep Underground Science and Engineering Laboratory (DUSEL). This retrospective rock mechanics study of the Davis cavern is intended to inform design of the much larger caverns and laboratory rooms being considered for the same 4850 Level. Provision for rock mass variability, sequential excavation, jointing and wall damage from blasting are included in analyses that were done using two different computer codes and methods (FLAC3D and UTAH3). The results are in agreement with observations and show that cavern stability is indeed the case. The main conclusions are: (1) if conventional scaling of laboratory rock elastic moduli and strengths is done, then 0.25 and 0.50 scale factors are reasonable, (2) measured statistical and spatial variability in rock properties should be incorporated into geomechanical analyses to better reflect reality, (3) discontinuities (“joints”) are essential to reliable analysis of excavation safety and when properly taken into account eliminate the need for empirical “scaling” of laboratory rock properties, (4) major geologic features such as rhyolite dikes and breccia zones may be important to excavation safety at Homestake and should be explicitly represented in analyses and (5) quantifying wall blast damage is important to engineering design of underground excavations.

Jan 1, 2012

By R. E. Heithecker

Zwolle oil field of Sabine Parish, La., is different from most oil producing areas of the State in that the oil is obtained from marl and chalk-rock formations. The thickness of the reservoir rocks averages 500 feet; but production is not continuous throughout this thickness, as the oil apparently is localized in vertical and nearly vertical solution cavities and channelways or in porous zones of limited horizontal extent. The nature of the oil accumulation has caused two outstanding peculiarities of the field: (1) About 60 percent of the tests drilled were dry holes and (2) there were many instances of well interference. Commercial production was discovered in November 1928, after 17 years of prospecting in and around the present limits of the area now developed which has a length of about 22 miles and a maximum width of 4 miles. The field had produced 10,266,896 barrels of oil to January 1, 1934. The oil ranges in gravity from 400 to 420 A.P.I. Although the field is divided into several districts which are more or less clearly defined and separated by unproved territory the term Zwolle field", as used in this report, includes the entire area from Blue Lake on the west side, through Zwolle proper, and eastward, including the Many or Eastern extension.

Jan 1, 1934

By Robert L. Slobod

In much of the work reported in the literature on long cores. true connate water value, probably have not been obtained because of insufficient flow of 011 to attain equilibrium. A -.satisfactory method for establishing connate water in long cores has been developed in which oil flow is maintained until no additiona1 water is displaced. INTRODUCTION Long cores have been used by sev-erals investigators in an effort to evaluate the efficiency of oil recovery for various producing schemes. The effects of many variables such as rate of displacement. pressure drop, volume of displacing medium, gas-oil ratio, inter-facial tension, and others have been investigated, and the merits of gas drive have been compared with water drive. In the older experiments no connate water was used. but in the more recent stndies the philosophy of the experiment calls for a core containing oil and connate water (irreducible water) as the starting point of the experiment. The method generally used to establish this condition in long cores involves dynamic' displacement wherein one or more phases are forced through the core. flow being maintained at a constant rate or at a constant pressure until a steady state is reached wherein there is no change of saturation with time. It is one purpose of this paper to point out that in much of the work reported in the literature true connate water values probably have not been obtained. The reason for this failure is pointed out. and a method for obtaining more reliable connate water values on long cores is presented. It is impossible at this time to completely evaluate the effect on the conclusions in the earlier papers resulting from the failure to obtain true connate water in the long cores, but some data are presented which indicate that serious errors may he present in many cases. MATERIALS AND APPARATUS Cores cut front outcrop sandstones (Strawn. Torpedo, and Elgin sandstones) with permeabilities of the order of 300 md were used. The major experiments were made with a core 18-in. long and 2-in. in diameter. Cores of the same diameter but only 12-in. long were used in a few tests? and in some work a core I-in. in diameter and 11-in. long was used. These materials were all somewhat bentonitic. 'To reduce the effect of such constituents, one of the cores (Torpedo No. 10) on which the most work was performed was acid extracted at the start of the experiment. Brine containing 50,000 ppm chloride and naphtha (Stoddard's Solvent) were used as the water and oil phases, respectively. The core was mounted in a rubber sleeve which forms the inner lining of a brass cylinder. In this arrangement2 the rubber sleeve is forced against the core by applying pressure to water in the annular space between the rubber sleeve and the brass cylinder wall. The core is therefore sealed in rubber so that all fluids introduced at the input end of the core flow through the core. With this equipment the core may be easily removed for inspection and analysis. Also, other cores may be introduced for study with no extra time for preparation such as is required when plastic mounting is used. When pressure or conductivity measurements are desired at intermediate points along tile length of the core, the brass cylinder comprising the outer jacket of the core holder is cut into section, of the desired length. Each section is then made up as an individual unit with its own rubber sleeve (see Fig. 1). The individual units are then butted up against a ring of plastic or other insulating material which carries an electrical contact for resistivity measurements and an opening which can be used for the measurements of fluid pressures. The individual units are forced tightly against the plastic ring separators and held in place with several tie rods. Inlet and outlet end butts of the same diameter as the core and several inches in length are provided to control the introduction and withdrawal of fluids and to complete the arrangement for sealing the core within the rubber sleeve. Fluid flow is maintained either by applying pressure to the liquid confined in a reservoir or by the use of a gear pump. The latter is preferable where continuous flow at a moderate rate over a long time interval is desired since a small volume of liquid can be readily recirculated using filters to prevent plugging of the core. EXPERIMENTAL The oven-dried core is weighed and is then completely saturated with brine

Jan 1, 1950

This manual provides instructions for installling, operating, and maintaining protective canopies on the Joy Mfg. Co. cutter. These instructions are based upon two actual installations: one made in a mine and one in the factory. The parts list and engineering drawings for the protective canopies are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other cutters with similar protective canopies. Skilled mechanics can determine if the instructions herein would be applicable to the other cutters and can determine any necessary modifications if they are not.

Jan 1, 1973

By K. C. Dean

The combination of flotation and chemical processing methods presented in this report of the Bureau of Mines enabled treatment of typical low-grade ferberite ores from the Boulder County, Colo. area, to produce specification-grade synthetic scheelite. The overall recovery from ore to synthetic scheelite was 87 percent, based on a flotation recovery of 93 percent and a similar recovery in chemical processing. Preliminary mineral dressing studies revealed that the physical and mineralogical nature of typical ferberite ores precluded high recovery of tungsten in plus 60-percent-W03-grade products by these methods. Therefore, the flotation research was focused on attaining plus 90-percent recovery in a concentrate containing 10 percent W03. Detailed studies were made (1) to establish optimum grinding conditions for obtaining adequate mineral liberation, (2) to develop collecting and modifying reagent combinations that would enable controllable selective flotation, and (3) to define the influence of different pulp solids, temperature, pH, and time for conditioning and for the rougher and cleaner flotation stages.

Jan 1, 1961

By C. C. Wright, R. J. Day

Although data on the exact tonnage of recoverable coal silt are not known, the quantity produced in 1943 was estimated to be over five million tons for the anthracite region of Pennsylvania alone. Since that time the recovery of the No. 5 buckwheat size previously included in silt estimates has increased greatly thus reducing the total silt tonnage. As a compensating factor, however, the methods of recovering silt previously escaping into the rivers and streams have been markedly improved so that the net figure may not have changed materially. Comparable estimates for bituminous coal are lacking, but undoubtedly the silt represents a significant tonnage. With the trend toward increased wet cleaning of the smaller sizes of bituminous coal, it is to be expected that even greater quantities of silt will be available in the future. The raw silt from anthracite collieries usually contains a high mineral matter content, but technological developments in fine coal cleaning have been making rapid advances and it appears probable that more extensive use of these methods will be employed in the near future. Bituminous coal silt in many instances contains a similar high mineral matter content. As with anthracite silt, however, the cleaning of this material, where necessary, appears both technologically and economically feasible. With a view to upgrading the size and value of silt, considerable laboratory and pilot plant work has been conducted by a number of organizations on what is commonly known as pelletization. Actually the process is one of extrusion in which the moist silt is extruded from a die in the form of rods, which usually break into relatively short lengths—a few inches long—as they fall from the die. Fig I is a photograph of some extruded 3/8-in. diam pellets and of the anthracite silt from which they were produced This technique of producing larger sized material from fines is by no means new, having been used extensively by the industrial carbon and clay industries for years.' The application of the process to coal silt appears, however, to be relatively new. The first major program of investigation dates back only to July 1945, when a group of engineers representing the Anthracite Institute, The Pennsylvania State College and the J. F. Pritchard and Co. conducted preliminary tests on the extrusion of anthracite silt at the Floridin Co. plant at Warren, Pa. Since that time these three organiza-tions—individually, together, and in cooperation with other interested groups— have actively pursued work on various phases of the problem. Much of the early history and details of the laboratory and pilot plant work by the Anthracite Institute, has been reported by Mulcey and Eckerd.2 It is the purpose of this paper to report additional information on the process, especially with respect to the factors influencing the quality and use properties of the product, and the current develop-

Jan 1, 1949

Escalating energy costs and tough environmental standards were two major factors affecting the minerals processing area in 1978 For the most part, new startups and research and development initiatives were directed toward improving process dynamics, investigating alternative processing strategy, and lowering unit costs. In the flotation area, the trend to larger machines continued. Scientific investigation of the modeling and process control of flotation was apparent, as was the research and development of new flotation reagents.

Jan 5, 1979

By C. W. Davis

THE name fuller's earth, which was derived from its early use in "fulling" or removing grease from woolen goods, is a term that is generally considered to designate mineral matter, containing hydrous aluminum silicates of the clay group, which has a high capacity for removing colors from oils, whether of animal, vegetable, or mineral origin. Fuller's earths are usually dried and may be "tempered" by heating or may be treated with water or reagents to improve their efficiency. For our purpose the term "acid-treated earths" will include those products from the partial decomposition of mineral water by acid which are equal to or more efficient than an untreated fuller's earth from Quincy, Fla., when used in bleaching mineral oil by the "contact" process. In general, the contact process for treating oils consists of heating and agitating a mixture of oil and finely divided adsorbent, the latter being subsequently removed by filtration. The term "adsorbent" is used because, although there has been a great deal of controversy over the mechanism of removal of impurities from oils by mineral matter, there is no doubt that adsorption, which involves the surface of the solid, plays a major part.1 The properties that make fuller's earth useful in the treatment of petroleum products by "percolation" and in the purification of edible oils by the contact process have long been studied, but the comparatively recent adaptation of the contact process to the bleaching of petroleum products has made desirable the further investigation of fuller's earth and other adsorbent earths.

Jan 1, 1929

By M. W. Grabinsky, B. D. Thompson

ABSTRACT: Use of cemented paste backfill (CPB) offers economic and environmental advantages over other backfill methods. However, many operations have limited knowledge of how their CPB behaves in situ. Therefore, to avoid over-pressuring containment barricades, backfilling strategies necessarily tend to be conservative. In situ monitoring at Barrick Gold Corporation’s Williams Mine and Inmet Mining Corporation’s Cayeli Mine has been conducted and factors controlling barricade pressures are demonstrated, including rise rates, binder content, stope geometry, and tailings properties. The application of barricade pressure monitoring on a stope-by-stope basis can increase backfilling efficiency and, thus, reduce stope cycle times, while maintaining optimal safety.

Jan 1, 2011

By B. C. Parks

This paper is a report on the relationships between petrographic composition, chemical composition, physical properties, and thermal behavior of banded bituminous coal. It describes the relationships between petrographic composition, behavior in various laboratory tests, and carbonizing properties of different petrographic types of coal that occur in relatively thick benches in a single bed of high-volatile A bituminous coal - the Hernshaw bed of Boone County, W. Va. Thin-section microscopic analysis and free-swelling index determinations of the thin-section samples were made of a standard column sample. A standard face sample, a representative channel sample, and representative samples of two prominent petrographic benches of bright and dull coal were subjected to chemical analyses and free-swelling-index, plasticity, dilation, agglutinating, low-temperature carbonization, and BM-AGA retort tests. A float-and-sink separation was also made of part of the standard face sample. The fractions from this gravity separation were subjected to petrographic and chemical analysis and free-swelling-index, plasticity, and dilatation tests.

Jan 1, 1959

Societal expectations about how the industry operates and treats its people will be a key driver in the development of the Australian mining industry over the next 20 - 30 years (Moffat, Mason and Littleboy, 2009). Understanding these expectations will be critical in maintaining what much of the minerals industry calls its 'social licence to operate', or its public acceptance or approval. Yet what constitutes this social licence is poorly articulated, with little published research exploring the concept at a local operational level or at the national level in Australia or internationally. This research aimed to explore the societal expectations of the mining industry in Australia and test a participatory methodology to articulate them. Three workshops were conducted with a sample of 24 members of the 'Australian voting public' to explore community objectives for the onshore exploration and mining industry, and the underlying expectations for how the industry should operate in the future. Qualitative analysis of this data revealed three overarching objectives for the onshore mining industry held by participants. They thought that the industry should: advance Australia's national interests (including social well-being); minimise environmental impact, and; act in a socially responsible manner. Within each of these three key themes, or objectives, a number of tensions were evident in the views of participants regarding the trade-offs they are willing to make to secure economic benefit from mining, as well as the basic conditions for socially acceptable mining. These data provide an insight into the conditions for a national social licence in Australia for the mining industry, and the means for its realisation.

Jun 1, 2010

By S Hanke, J Burden, P Spies

The Waterview Connection will complete Auckland’s long-planned Western Ring Route, a 48 km north-south motorway alternative to State Highway 1 that bypasses the central city to the west. The project involves construction of 5 km of new motorway – half of it underground in tunnels – to connect the Southwestern (State Highway 20) and Northwestern (State Highway 16) motorways.The Western Ring Route will link the major population and industrial centres of Manukau, Auckland and North Shore to give the region the connected and resilient strategic road transport system it needs to underpin economic growth and sustainable development. It will also provide a direct motorway link between Auckland’s central business district (CBD) and international airport.The project involves construction of twin 2.4 km driven tunnels with an outside diameter of 14.41 m beneath residential suburbs, a major arterial road and a rail corridor. Enabling works began in January 2012 while tunnel construction using an earth pressure balance (EPB) tunnel boring machine (TBM) began in November 2013.This presentation introduces the Waterview Connection project, its role in the development of the Auckland motorway network, its procurement process, the alliance delivery model and an overview of the project’s design features and construction progress to date.Design and construction highlights of the presentation include the TBM start-up, turnaround and breakthrough arrangements as well as the experience gained during the first tunnelling drive. The presentation also covers an innovative process developed for invert construction behind the TBM that is independent of tunnel excavation.CITATION:Spies, P, Burden, J and Hanke, S, 2014. The Waterview Connection Project – progress to date, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 519–540 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By N. D. Schupp

The Doe Run Company's Herculaneum, Missouri lead smelter has existed in continuous operation since 1892. Throughout the history of the plant extensive developments have been made to improve throughput, increase productivity, decrease operational costs and improve technology, while remaining an environmentally responsible producer of high quality primary lead in the international market. This paper provides an overview of the Herculaneum smelter, focusing on the most recent configuration of the operations. The paper includes discussion on all the aspects of primary lead production at the Herculaneum smelter.

Jan 1, 2000

By W. M. Dressel

A simple, reliable field test for beryllium in rocks has been developed by the Rolla Metallurgy Research Center of the Federal Bureau of Minas. A small portion of the pulverized rock is fused with a sodium carbonate-sodium hydroxide flux in a wire loop. The fused mass is dissolved in water, a few drops of quinizarin solution are added, and the solution is viewed under ultraviolet light. A pink-to-orange fluorescence reveals the presence of beryllium in a sample containing as little as 0.013 percent beryllium (0.26 percent beryl). INTRODUCTION New and potential uses for beryllium make necessary a more intensive search for this metal, which is so similar to aluminum in its chemical reactions that it is not separated from aluminum in ordinary chemical analyses. The principal ore mineral of beryllium is beryl, a beryllium-aluminum silicate, which contains only 5 percent beryllium. This mineral is so similar to quartz in appearance that it is not always possible to distinguish one from the other in the field. While the distinction may be made easily with a petrographic microscope, few prospectors have access to such an instrument, and fewer still know how to use it.

Jan 1, 1960

By M. C. Irani

This study is a survey of supply and demand for minerals, metals, alloys, and compounds used by the chemical industries in the Ohio River Basin (ORB) area of Ohio, Pennsylvania, and West Virginia during 1967. Data for the study were obtained from completed questionnaires received from chemical manufacturers and from interviews with officials of chemical companies and mineral producers and distributors. The information includes kind, quality, quantity, values, sources, specifications, uses, and methods of transportation. Results of the study show that of the total value of mineral materials consumed by the chemical industry, manufacture of inorganic chemicals consumed 46 percent; fertilizers, 22 percent; and soaps and detergents, 19 percent. Fifteen commodities accounted for 91 percent of the total value of mineral materials consumed. Five of these--phosphates, potash, salt, sulfur, and titanium dioxide--accounted for 59 percent of the total.

Jan 1, 1970

By G. A. Beiswenger

The application of the law of supply and demand to the sale of crude oil is generally conceded, but the motives underlying the buyer's (refiner's) demands are not always obvious to the seller (producer). In some cases this obscurity has led to the conclusion that the refiner may be unnecessarily particular when he selects one crude and rejects another. This preference, however, is very largely the reflection of the refiner's product demands and the quality of the stocks obtainable from the selected crude. The purpose of this paper is to point out critical characteristies of the major classes of refined products and to show how crudes vary in their suitability for such products. With relatively few exceptions, available processing methods and addition agents make it theoretically possible to produce any type of refined product from any crude source, although it may not be economically sound to do so. The widespread application of thermal cracking for converting higher boiling stocks into gasoline is well known. More recently cracking and refining in the presence of catalysts9 have been developed, as well as various processes for polymerizing lighter hydrocarbons into gasolines having desirable characteristics.6 For several years, selective solvents have been applied commercially to refining inferior quality kerosene, Diesel fuel and lubricating oil distillates.3 Improved methods for refining lubricating oils from crude residual4 formerly suitable only for fuel, are now in use and a number of special solvent processes are available for dewaxing lubricating oils to low pour point.5 These improved refining methods have been developed not only to meet the demand for improved product quality but also to enable the refiner to obtain quality products from crude sources that would not yield such products by the older refining methods. In many cases, the utilization of these modern refining tools necessitates an appreciable expenditure for equipment as well as added manufacturing costs, and their application therefore must be justified economically. Despite the availability of such tools, the added processing costs involved and yields obtainable may render their application entirely impractical. To illustrate this point, inspections of typical cuts from various crudes

Jan 1, 1940

By Leonard F. Heising

At the Groveland-mine iron ore is mined by open-pit methods and concentrated by means of spirals and flotation. A brief history of the mine and its early development is given. The ore deposit is described, with emphasis on those physical characteristics that affect the choice of mining and milling methods. Development and mining, which include breaking ground, loading, transportation, engineering, and operating control; are explained, and the milling method is described Mining and milling costs are given in percent of total cost.

Jan 1, 1963