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By K. Lomberg

In this paper the process of sampling and assaying as it relates in particular to the platinum group elements (PGEs) is presented. A discussion of the geology of PGE deposits is included to provide an understanding of the mineralization that is considered necessary prior to sampling, as this has a direct bearing on the mineral resource estimate and also the selection of an appropriate mining cut. The discussion includes the selection of the sampling technique (drilling or face sampling), the size of the sample relating to the requirements of the laboratory, the potential mining cut, as well as a reference to sampling theory. The selection of an assay technique that is appropriate and will yield the optimal result based on sample turnaround, precision, accuracy, and cost is then considered. Examples are drawn from work undertaken on the Bushveld Complex (Merensky Reef, UG2 Chromitite Layer, Platreef) and Great Dyke (Main Sulphide Zone). A discussion of the appropriate QA/QC programme includes the chain of custody, CRM selection and the QA/QC process. Keywords sampling, assaying, QA/QC, platinum group elements.

Jan 1, 2014

By Robert L. (Original by) Llewellyn

Many of the problems that occur in the preparation plant originate from practices in the mine. Impurities in raw coal can be in the seam itself or from extraneous material taken in mining from the roof or bottom. In the case of underground mines, the choice of mining equipment will affect the size consist and the amount of extraneous material included with the coal. Also, governmental regulations concerning the degree of rock dusting, gobbing underground, and cleanup have increased the dirt in raw coal. Sulfur dioxide emission standards, on the other hand, are pressuring the coal industry to clean coal more thoroughly. Coal supplied for coking purposes is nearly all upgraded by washing, while for the largest market, electric power generation, a high proportion is shipped as a raw product with processing, in whole or in part, only necessary when excess impurities are mined with the coal. This chapter will deal primarily with plants that process or wash coal to some extent (Fig. 1) and only incidentally with mines shipping raw run-of-mine coal crushed to a top size of, usually, 51 to 102 mm (2 to 4 in.), with little, if any, other treatment.

Jan 1, 1981

The Friday morning session of, the Forty-seventh Meeting of the Rocky Mountain Coal Mining Institute was called, to order in the junior Ballroom, Hotel Utah, Salt Lake City, Utah, at 9:20 o'clock a. in., with Mr. Paul L. Shields presiding. CHAIRMAN SHIELDS: Let us get started, gentlemen. We are late now. From the looks of this agenda we are going to have a busy forenoon. The first item on this program is a talk on "The Second Underground. Gasification Experiment at Gorgas, Alabama," by Mr. James L. Elder.

Jan 1, 1951

By D. Eugene Rannels, Sarah E. Dunsmore

"Dunsmore, Sarah E., and D. Eugene Rannels. Extracellular matrix biology in the lung. Am. J. Physiol. 270 (Lung Cell. Mol. Physiol. 14): L3-L27, 1996.-The lung and other organs are comprised of both cellular and extracellular compartments. Interaction of these components modulates physiological function at the organ, cellular, and subcellular levels. Extracellular components in the gas-exchange region of the lung include both noncellular interstitium and basement membranes. Connective tissue elements of the interstitium in part determine ventilatory function by contributions to tissue compliance and to resistance of the diffusion barrier. The basement membrane underlies cells of both the alveolar epithelium and the capillary endothelium; basement membrane components exert biological effects on adjacent cells through receptormediated interactions. This review emphasizes current knowledge concerning the composition and biological activity of extracellular matrix in the alveolar region of the lung. Matrix synthesis and turnover are also considered. Directions for future research are suggested in the context of current knowledge of the lung and other model systems. EXTRACELLULAR MATRIXEXTRACELLULAR MATRIX is a general term that encompasses components of the basement membrane and interstitial connective tissue. The extracellular matrix has many functions. It provides structural support, compartmentalizes tissues by separating epithelium or endothelium from interstitium, and serves as a physical barrier. Both in vivo and in vitro studies show that extracellular matrices also affect cell shape and function. The matrix elicits a variety of cellular responses, including adhesion and spreading, changes in cytoskeletal organization and differentiation, formation of focal contacts and stress fibers, stimulation of proliferation and migration, induction of polarity and gene expression, alterations in metastatic activity, and outgrowth of cell processes (for review see Refs. 387, 462). Cellmatrix interactions play roles in embryonic development and organogenesis (for review see Refs. 1, 91), in wound healing (for review see Refs. 145, 327), iri metastasis (for review see Refs. 430, 431), and in angiogenesis (for review see Refs. 185, 186). The extracellular matrix is the subject of a large volume of literature. In 1994, over 1,000 articles contained extracellular matrix in the title or abstract. After a brief discussion of key aspects of extracellular matrix biology, this review will focus on the extracellular matrix of the lung."

Jan 1, 1998

By G. J. C. Young

The paper describes the replacement of a conventional filtration, clarification and zinc precipitation plant by a carbon in pulp (CIP) electrowinning plant, with the objective of improving the recovery of gold from cyanide leached, acid plant calcines. The discussion covers the early laboratory studies to the design and erection of the full scale plant. Particular emphasis is placed on the problems encountered with commissioning and the strategies which were employed to solve them.

Jan 1, 1982

The Golden Plateau Mine is located at Cracow in central Queensland, 350 kilometres north west of Brisbane. The mine was operated by Golden Plateau NL as an underground mine from 1933 to 1976 with a total production of 18.5 tonnes of gold. Prod

Jan 1, 1994

By A B. Richards

Effective control of blast vibration and flyrock requires that significant factors be identified and quantified, that the blast be designed to ensure both blasting efficiency and compliance with applicable limits, and that the blast design be effectively implemented by field personnel. Significant factors contributing to ground vibration and airblast are: charge mass; distance and direction relative to the blast; drilling design: burden, spacing; stemming height and material type; hole diameter and depth; and initiation sequence and direction.In addition, airblast may be strongly influenced by shielding and meteorological conditions. Ground vibration is also influenced by the transmission characteristics of the ground and soil. Flyrock throw is determined by charge mass, burden, stemming height, blasthole diameter and depth. The contribution of each of the factors has been quantified and models developed to enable the environmental outcomes of blast design to be predicted. Environmental blast design is necessary to ensure compliance with regulatory limits and the implementation of æsafeÆ exclusion zones for flyrock clearance. This paper discusses the models used for environmental blast design and demonstrates the often significant effects that lapse during implementation of the design can have on predicted outcomes. In practice, drillers and shotfirers are sometimes confronted with situations that require modifications to the blast design to cope with the real site situation. Methods are presented that may be used by drillers and shotfirers to evaluate the effect of these modifications, the tolerances that must be reached during their work practice and checking procedures, and the consequences of their actions.

Jan 1, 2004

By E. S. Bumps, W. F. Craig, M. Baeyertz

Metallurgists have looked at fractures macroscopically for many years and have evolved a vocabulary in which such words as "cleavage," "brittle," "shear," "ductile," "granular," "fibrous," and "silky" are used to describe the appearance of the fractured surface; but the meaning of these words in terms of metal structure is not well established. Observations of the structural meaning of "brittle" and "ductile" fractures in plate steels have been made, notably, by Kramer and coworkers1 and by Tipper.2 Grossman3 has studied the fracture of tempered martensite and combinations of ferrite and martensite. Notwithstanding these and other less concerted attacks on the problem, present understanding of fracture rests more on assumptions and logic than on experiment. It is the purpose of this paper to add a little to the growing fund of experimental observations of the nature of fractures in steel. The particular fractures to be described were obtained in conventional impact testing of an ordinary structural steel shape. In impact tests of the Charpy type, the specimens fail in a characteristic manner that depends on the steel and the temperature of testing. With ordinary structural and many other steel products, an appropriate range of testing temperature will cause a considerable change in the energy absorbed before fracture. This change is known as the energy transition and is accompanied, more or less closely, by alteration in the appearance of the fracture. At testing temperatures below the transition, the terms "brittle," "cleavage," or "granular" are used to describe the fracture; above it, "ductile" or "shear" are often used. Within the transition, the fracture changes from "brittle" to "ductile" by a progression in appearance, wherein the "brittle" portion of the fracture becomes restricted to a smaller and smaller central area of the fracture, as the testing temperature is raised and the "ductile" type of fracture is approached. All this is well known to metallurgists. The specimens under consideration are of the conventional V-notch Charpy type. They were taken from a structural steel shape of the following analysis: C Mn P S Si 0.17 0.46 0.009 0.029 0.03 Both longitudinal and transverse specimens were tested and examined. Fig 1 shows the energy values plotted against testing temperatures in the usual way. The curves for both longitudinal and transverse specimens show an energy transition, although the maximum energy absorbed at testing temperatures above the transition is greater in the case of the longitudinal specimens. Fig 2 illustrates the changes in the macroscopic appearance of the fractures that are associated with the energy transitions shown in Fig 1. Macrographs of the fractured surfaces of the specimens have been identified with the fracture ratings at intervals on each fracture curve. The numerical fracture rating on the ordinate of Fig 2 indicates the percentage of the area of each fracture that was considered to be "brittle" on macroscopic observation. Such rating of the fracture type in impact tests is now customary in many laboratories. Hereafter the specimens will be identified by reference to Fig 2 as 90 pct "brittle," 80 pct "brittle," and so on, in accordance with this macroscopic evaluation of the appearance of the fractured surface. The discussion of the fractures is divided into three parts. The first two are concerned with the mode of fracture and its relation to general structural features. As the same metal-lographic features occur in both longi-

Jan 1, 1950

Legislation up to the early 1950s prevented the mechanical extraction of pillars. The mines operating at that time had formed extensive areas of pillars. When permission for the mechanical extraction was gazetted, conventional equipment was employed for pillar extraction and generally using hand mining systems. The mid-fifty's saw the of continuous miners. These machines eliminated the disadvantages of conventional equipment and the necessity for multiple working places. Some new layouts for panels emerged; however, actual extraction methods of pillars still followed closely that of hand mining. During the early sixty's the extraction of standing or new formed pillars was undertaken by the "open-end lift" or a "split and lift" method.

Jan 1, 1974

Black coals occur in most of the major sedimentary basins in Australia. In addition to the better known Permian coal occurrences of the Sydney, Bowen, Oaklands and Galilee Basins, coals of Permian age occur in the Arckaringa Basin in South Australia, the Bonaparte Basin in Northern Territory and the Collie, Perth and Canning Basins in Western Australia and the Tasmania Basin in Tasmania. Coals of Triassic age occur in the Ipswich Callide and Tarong Basins in Queensland, the Tasmania Basin in Tasmania and the Leigh Creek area in South Aus- tralia. Coal bearing rocks of Jurassic age occur in the Mulgildie Basin and Maryborough Basins in Queensland and in both the Queensland and New South Wales portions of the Clarence Moreton Basin and Surat Basins. They also occur in the Perth Basin in Western Australia. Rocks of Cretaceous age known to contain coal occur in the Styx, Maryborough and Laura Basins in Queensland, the Gippsland Basin in Victoria and both the Queensland and New South Wales portions of the Surat Basin. The coal measures have been deposited in a variety of sedimentary environments and the coals vary widely with regard to thickness, extent, banding characteristics, maceral and ash content. However, they are generally of low rank and most are suitable only for steaming.

Jan 1, 1975

By Milton H. Fies

Although pig iron from iron ore and red cedar charcoal preceded the mining of coal by many years, for tradition says that Alabama iron was used to shoe the horses of Andrew Jackson's soldiers, coal was not produced until 1830. In that year, coal was mined in Tuscaloosa County, in the vicinity of what is now the University of Alabama, and shipped on flat boats (obviously during the wet season, for there were many shoals) down the Warrior River to Mobile. About that time, the first railroad, the Decatur & Tecumseh, was being constructed in northern Alabama to overcome the obstructions to freight traffic caused by the now well-known Muscle Shoals in the Tennessee River. This railroad was patterned after a railroad at Mauch Chunk, Pa., which was used for hauling anthracite from the Panther Creek valley. The Alabama railroad, which required about four years to complete, was 46 miles long and was used solely for the transportation of cotton. Although it was a failure, it demonstrated the practicability of the undertaking, and the succeeding railroads, which were begun in 1834, 1848, 1852, and 1853, added immeasurably to the development of the coal resources of the state. Between the years 1830 and 1860, practically all the coal mined in the state was dug from the outcrop near the river or from the river beds, and shipped by boat to Mobile. Transporting coal down the Warrior River was an undertaking of great risk, required much skill, and frequently had heavy losses. It is recorded that this coal was sold to the gas company in Mobile in 1844; it was most likely mined from the Black Creek Seam. In 1914, on the completion of Lock 17, the Warrior River became a navigable stream from 9 miles above Cordova, Ala., to Mobile and offers a great opportunity for the future development of the coal resources of the state. Coke for foundry use was first made in Alabama in 1855. It was 21 years later, however, in 1876, that pig iron was made from Alabama ore with Alabama coal.

Jan 1, 1925

By Lorenz E. Sieffert, Lawrence B. Berger, H. H. Sehrenk, Ralph W. Stewar, James A. Gale

"INTRODUCTION The purpose of the investigation discussed in this article was to evaluate the toxic hazard from gases produced when thermosetting plastic materials used for electrical insulating purposes are burned or thermally decomposed in enclosed spaces. For brevity the term ""toxicity"" is used throughout the article to refer to the nature of gases produced under these conditions. A need for immediate study of the problem was created as a re¬sult of the battle damage reports received from various United States Fleet units. These indicated that the fumes emitted when these materials were burned or thermally decomposed had, in several instances, resulted in toxic atmospheres. In attempting to develop a suitable test method for evaluating toxicity, it was recognized that no single test procedure could be expected to duplicate the variety of conditions that might exist in an actual fire aboard ship. In view of the immediate need, however, it was felt that considerable information could be obtained, at least to classify comparatively the several types of materials as to the toxic effect caused by burning or thermal decomposition, through the development of a sound empirical method which could be applied to all of the materials. On this basis, it was decided to modify the Navy flame resistance test for thermosetting plastics to render it applicable to the determination of the toxic, gases evolved when this test was employed. A wide variety of materials was tested, both molded and laminated, to cover the types commonly used by the Navy in electrical applications. Toxicity determinations were conducted at the Bureau of Mines Central Experiment Station, Pittsburgh, Pa. Parallel tests, to determine the flame resistance of the materials, were conducted at the Material Laboratory, U. S. Navy Yard, New York, N. Y."

Oct 1, 1947

By Walter D. Holland

This document is one of a series of instruction guides developed to help instructors present health and safety training courses to workers in the metal and nonmetal mining industry. This course is intended to provide above ground metal and nonmetal mining employees with training which will assist them in performing their work safely and healthfully. A document entitled, "Airborne Contaminants in Above Ground Metal and Nonmetal Mining and Processing Work Areas," is used as a manual for the students during the course. The unique features of the teaching guide are thumb rules for recognizing hazardous situations, candidate contamin¬ants for each work area and descriptions of control devices and work procedures.

Jan 1, 1977

By James P. Roe

I. INTRODUCTION. THOSE who deem the subject of this paper an old and super¬seded one may recall with advantage the words of the great proverb-maker, bidding us to seek the new in the ashes of the old. The manufacture of wrought-iron began with the small hearth built upon an eminence, and relying on the wind for blast. Next came, either the hearth about 12 in. in diameter by 2 ft. in height, blown by a man operating two goat-skins for bellows, or, a hearth of greatly varying diameter and about 10 ft. high, depending for its blast upon natural draft. The former appeared in India, the latter in Burmah; and both were in operation until quite recently, though their origin is lost in prehistoric times. The Catalan forge was the evolutionary descendant of the foregoing, and the parent of the Blase-ofen, which in turn led to the high bloomary or " Stückofen," the father of the blast-furnace, as a producer of cast-iron. The production of cast-iron checked the growth of the direct processes; and led to the introduction of various hearths, such as the Walloon, for low-silicon irons; and the South Wales process, combining the run-out fire with the finery, for higher-silicon irons. Some of these are still in operation in localities possessing the necessary raw materials; and their product is used for purposes requiring wrought-iron of exceptional quality, the supply of which is still smaller than the demand. We have to look back but a century and a quarter to see the introduction of the puddling process by Henry Cort; a process which, reinforced by the iron-oxide bottoms and fettling of Hall, was not less revolutionary in character, and more revo-

Jul 1, 1905

By L. B. Berger

Studies showing the effect of mixing hot exhaust gases with the intake air of a four-stroke-cycle Diesel engine are described. The results indicate a marked increase in carbon monoxide in tip exhaust gases, a decrease in oxides of nitrogen, and no significant effect on aldehydes. The increase in carbon monoxide was greater at higher fuel-air ratios and was caused partly by the increase in fuel-air ratio end partly by the decrease in oxygen concentration resulting when exhaust has was added. The application of these results to the use of Diesel engines underground is considered.

Jan 1, 1940

By G. R. Hopkins

The average quantity of heat needed to refine a barrel of crude oil in 1934 was 638,000 B.t.u., or about as much heat energy as contained in 5 gallons of fuel.oil. Although the total heat utilized in 1934 was slightly above 1933, crude runs to stills increased 4 percent, hence the average requirement per barrel declined from 660,000 B.t.u. in 1933 to 638,000 B.t.u. in 1934 (see fig. 1). The average for 1934 constitutes a new record for firing efficiency, being just under the previous low of 1929. Heat consumption at refineries depends on many factors, of which the trends in yields of gasoline and lubricating oils are probably most important. The yield of gasoline is indicative of activity at cracking plants, which typo of plant utilizes more thou the average amount of heat per gallon of product. The yield of lubricating oils is indicative of the extent to which crude oil is refined; that is, it takes considerably more heat to refine a barrel of crude through lubricating oils than it does to separate only gasoline and kerosene. The yield of gasoline decreased from 43.7 percent in 1933 to 43.4 percent in 1934; on the other hand, the yield of gas oil and fuel oil increased. Although the yield of lubricating oils increased slightly in 1934 the theoretical increase in fuel requirements probably was offset by technical improvements, such as solvent refining. Although no outstanding technical developments of a fuel-saving nature were made in 1934, some progress undoubtedly was recorded. Heat exchangers, an effective fuel-saving device, wore enlarged, and some refiners now take off several cuts before the crude reaches the pipe stills. The total capacity of pipe stills increased 2.5 percent in 1934, and many of the less efficient shell stills were torn out.

Jan 1, 1935

By Frank J. Weibelt

In accordance with provisions of the Strategic Minerals Act of 1939, the Bureau of Mines surveyed the chromite occurrences in California. The Seiad Creek deposit afforded excellent opportunity for developing reserves that could be used by the nation in case of critical shortages of the mineral. Subsequently an exploration and development program was undertaken in April 1941, which was concluded in October of the same year. Work included road construction, diamond drilling, drifting and crosscutting, surface trenching, and sampling.

Jan 1, 1949

By Liu Q, Siefken T. C, Misra V. N

Investigation of the differential flotation characteristics between arsenopyrite and pyrite in a ore concentrate have been carried out on a laboratory Leeds flotation cell. Experimental results indicate that some limited separation between arsenopyrite and pyrite is possible by differential flotation under the conditions of high pH and low pulp redox potential. The best performance in this testwork was achieved by using an oxidizing agent at pH 10.7. Of the oxidizing agents tested, NaOCI gave better oxidizing effect than KMnO4. It has also been observed that the pulp redox potential depends on the pulp pH value. At high pH values a hydroxide layer is formed on the arsenopyrite surface, which has the effect of a depressant on the arsenopyrite.

Jan 1, 1992

By Richard L. Wedertz

Although the physical appearance of excavating equipment doesn't seem to have radically changed over the past decade, important changes within the products and an innovative attitude on the part of the engineer in his design approach is becoming increasingly evident. The new philosophy is to go beyond simple refinements of existing designs that simply produce a machine which further reduces overall cost per ton or per cubic yard of material moved and to do it more efficiently than ever before. Standard ideas and preconceived notions have been discarded and have given way to providing a design and a machine that is best suited to get the job done. Understanding that the application will not always fit the machine, but, in most cases, the machine should fit or suit the application is a foremost consideration in the engineers' design criteria.

Jan 1, 1973

By Ernst P. Hall

The Irwin Basin. (Fig. 1)* is a synclinal or shoe-horn *Figure numbers throughout refer to color slides not included with the preprint shaped basin in the Pittsburgh Coal Seam, It is approximately 10 miles wide and 22 miles long at its maximum points. The surface of the land above the basin is hilly, rolling farmland,, typical of this area of Pennsylvania, and it is criss-crossed with streams and highways and liberally dotted with farm houses and communities. In-general the coal is pitched from north to south with a total drop of 610 feet'. The coal seam cross-section from east to west is bowl-shaped and rises as much as 375 feet from the low point of the bowl to-the-outcrop. Cross-sections showing coal elevations are shown on Figs, 4 and 50 Ground cover above the coal will vary from 0 to 550 feet, averaging about 350 feet throughout the area. This area is richly endowed with a history of coal mining. The first car of coal shipped cast of the Allegheny Mountains was mined in the Westmoreland Coal Company's Shady Grove (later North Side) Colliery in Irwin, Pa., early in 1853, This mine was opened in 1852 by Coleman, Hillman & Company. The coal was hauled from the mine to the freight station by horse-drawn wagon and. loaded into a then "standard" box car of 18,000-pound capacity. Coal mining in this region flourished and grew as steel production in nearby Pittsburgh demanded more and more of the high quality, metallurgical-grade coal of the region.

Jan 1, 1959