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By David B. Campbell

Production of both metallurgical and thermal coal represents a significant sector of the mining economy of British Columbia. The coal measures are located in the Rocky Mountains, and the majority of the coal is produced by open pit mining. The coal seams occur interbedded with siltstones, sandstones, mudstones, and shales. Consequently, large volumes of waste rock are generated in the course of open pit mining. The waste rock is consigned to waste rock piles that of necessity must be developed on moderate to steeply sloping terrain. Some of the waste dumps currently under development will ultimately contain in excess of 500 million cubic meters of material, and some of the proposed waste piles will attain heights in excess of 300 m. These waste piles must be developed in a manner that will assure their stability through all stages of development, as well as over the long term after mining operations have been completed. This paper describes methods of waste dump development, factors affecting stability, modes of potential failure, and a simple method for monitoring movements to provide a warning of pending unstable conditions.

Jan 1, 1985

By Albert W. Giles

The splitting of the coal by partings is a familiar feature of many coal beds. The partings are normally argillaceous, more rarely sandy or calcareous. The material is usually fine-grained, less frequently coarse-grained to conglomeratic. Many partings are wedge-shaped, others are lenticular, and in some coal beds thin partings but one or two inches thick persist as thin sheets throughout areas of regional extent. The origin of the partings differs, and in some cases is obscure and uncertain. Origin of Thick Partings Wedge-shaped Partings Wedge-shaped partings are normally of indefinite linear extent but of short transverse section. They are developed adjacent to the borders of the original peat-forming swamp or around islands formed within the swamp, hence their presence is indicative of the approximate limit of the coal bed or of an interruption in the continuity of the coal bed. Following deposition of the parting gradual reestablishment of swamp conditions is followed by burial of the parting with accumulating peat. Partings developed adjacent to the borders of swamps normally thicken toward the periphery of the swamp and represent either detrital materials carried in from adjacent land areas during floods or materials carried in by advancing waves and currents after a barrier confining the swamp had been breached by the waves. Partings formed in the manner first mentioned should become coarser and more arenaceous toward the source of supply of the detrital materials, and the overlying and underlying coal should gradually grade into carbonaceous shale as the margin of the original swamp is approached. Partings formed by advance of waves across a barrier should be largely or entirely arenaceous, thin wedges of short longitudinal section, possibly with fossils of marine or brackish affinity. The subjacent coal normally should "pinch out" against the barrier, and the overlying coal continue to the barrier, or even extend across it, depending on the geographic conditions established following the breaching of the original barrier. Islands may be formed in swamps in a number of ways. They may represent local uplift of the swamp floor during earthquakes, or

Jan 1, 1934

By James T. Kemp

SOME interesting and, to American eyes, rather unusual processes for refining impure aluminum derived from scraps were found by American and British investigators who went into Germany in 1945 for the Technical Industrial Intelligence Committee Of the Joint Chiefs of Staff. What was found was recorded in a series of reports (see page 14), many of which have been released for general reading. This paper gathers under one title and summarizes the German work in refining light metal scrap. Reference must be made to the original reports for greater detail. Basically, the occasion and stimulus for the German developments in treating light metal scrap were hard necessity. Germany needed the metal for a rapacious war industry. Adequate supplies of new aluminum from reduction works were not assured. Great quantities of airplane and other light metal war scraps were forecast. It was evident that the scrap metal would have to be reabsorbed by the producing industry and would have to be kept of good quality. The normal current production of manufacturing scrap was being and could be consumed as generated. It offered no technical problem. The mixed scraps, especially those arising from crashed and decommissioned airplanes, however, presented problems of another kind. AIRPLANE SCRAP The recovery of usable aluminum alloy from the mixed assemblies that made up the piles of airplane scrap was attacked in different ways by different groups and with differing degrees of success. Three procedures actually were used On a commercial scale, one was in pilot-plant stage and another had come to a halt in the laboratory a year before Germany collapsed. Four of these five processes actually involved "refining"; that is, some measure of purification of the metal after melting. SORTING AND SEPARATION ON A SLOPING HEARTH The simplest procedure for utilizing airplane scrap involved no refining in the strict sense of the word. This was the practice adopted by two representative plants visited by the author, the Leipziger Leichtmetalle Werke, Rackwitz, Saxony, and the Vereinigte Leichtmetalle Werke, Hanover. These firms did essentially the same thing that was done in England but not with equal success, to judge by their shorter experience, the smaller tonnage handled and by the number and quality of alloys produced. The two German firms named rough-sorted scraps by their easily recognizable alloys, essentially by part and shape. They used hand labor to chop and hack and tear apart. The easily separated heavy metal and nonmetallic scraps were discarded as they were found. Steel and the higher-melting-point metal parts riveted to aluminum or built into

Jan 1, 1947

By V. F. Swanson

A petrographic study was made of the type and sources of mineral contamination occurring in Florida phosphate rock products. Emphasis was placed on contaminants in the screened rock (+1 mm), since this portion of the product undergoes no physical beneficiation except for scrubbing to remove slimes. Since iron and aluminum contents of the finished product affect the salability, special emphasis was placed on identifying types and sources of these contaminants and relating chemical composition to visual characteristics. Wavellite derived from the overburden was the major aluminum contaminant with some aluminum being included as secondary clay balls. Iron occurred as phosphates in the overburden and as colloidal oxides included in the phosphate pebbles. Chert and limestone contamination derived from the Hawthorne formation underlying the phosphate matrix.

Jan 1, 1972

By E. Gybbon Spilsbury

The recovery of gold and silver from their ores by means of the cyanide process has been so successful in the last few years that ally radical improvement would seem impossible; yet the appliance to which I wish to call attention in this paper is really a radical departure from the methods now in general use. The most modern and approved of these, known as the all-slimillg method, depends for its success on the grinding of the ore so fine that practically 90 per cent. of it will pass through a 200-mesh screen. The slimes thus produced are then agitated and aerated in tanks of various types. The main object of this treatment is to insure such a thor-

Jan 1, 1911

By Henry F. Cooper, Lee Burford, John C. Thompson

In the past year or two, considerable effort has been expended to calculate the spherical wave propagation phenomena associated with explosions in a "hard rock" medium (Godfrey, 1969; McKay and Godfrey, 1969; Burford, et al, 1970). This effort was stimulated primarily by the recognition that early calculations predicted peak particle displacements which seriouly disagreed with field data. In most of the calculations mentioned above, rock was modeled as an inelastic continuum (see for example Isenberg, et al, 1970 for some recent results using "classical" elastic-plastic material property models). However, several investigators (Handin, et al, 1967; Cherry, et al, 1967) have shown that the simple classical yield surface models cannot simultaneously account for the observed brittle failures of intact materials under compression, extension and torsion. One approach to more correct modeling of dynamic rock behavior is to make the inelastic model more and more sophisticated. For ex- ample, recent experiments at the University of Utah (Swanson, 1969) have suggested possible modifications to the yield surface model that could better account for the ductile behavior of intact granite sam- ples under various states of stress. The approach followed in this paper proceeds in an entirely different direction. We want the physics which is built into our conception of rock to be as simple as possible while at the same time reproducing the most important features of rock's behavior. Therefore, we abandon the requirement that rock be treated strictly as a continuum. Instead we consider a "discontinuous" model in which one of the most significant characteristics of rock is treated..

Jan 1, 1971

By S Bankoff

INCE1 proposed that electrostatic attraction between oppositely charged particles was responsible for slime-coating. Del Giudice2 postulated the metathetic formation of a cementing compound. Wark3 suggested that prevention of slime-coating was related to peptization of the slime. [ ] In the experiments of Table I the technique employed was essentially that of del Giudice, with the difference that the particle was examined under a film of water rather than dry.4 In general, the polished particle was agitated for 2 min. in a pulp consisting of 12.5 grams of the slime (-200 mesh) and 50 c.c. of distilled water, washed in three baths of distilled water, and examined at 220 diameters with the Leitz Ultropak. Observations of Brownian movement were made at 850 diameters with dark-field illumination. Several of these experiments do not jibe with the metathesis theory. According to published solubilities,5,6 the lead salts of the anions in experiments c through g are more insoluble than lead carbonate, there- [ ] fore should prevent the formation of lead carbonate on the galena surface. In experiment i the calcium oxalate, which presumably was on the calcite surfaces, should have permitted the formation of a lead carbonate cement by virtue of its greater solubility. Experiments j through m show that the addition of lime accelerates the deposition of quartz onto a galena surface. The writer is unable to postulate a satisfactory cementing compound, according to the metathesis theory, to explain this effect. These experiments led to the conclusion that the metathetic formation of a cement-

Jan 1, 1941

By Tran K. Van, Francois E. Heuzé, Richard E. Goodman

Sound design of structures founded in or upon rock requires that the deformability of each rock member involved be characterized. This can be done by means of loading tests (plate bearing, flat jacks, borehole jacks, pressure chambers, etc.) or through convergence measurements (tunnel convergence, roof sag, etc.) in exploratory works. Analysis of data will be qualitative (degree of nonlinearity, creep behavior, scattering of results over a number of sites, etc.) and quantitative (modulus of elasticity or deformation). Some of these tests involve a very bulky apparatus and are expensive to perform. On the other hand, for the purpose of mapping and describing the various rock members which occur within a given site, many feet of diamond drill holes are frequently completed. Even with the optimum equipment and expert drillers, however, quantitative characterization of the rock units on the basis of tests on returned samples is apt to be misleading; the softer and weaker components of the rock tend to be lost and the fabric of the rock block- fracture system in situ is not sampled. Laboratory moduli of elasticity have proved to be consistently higher than in-situ values selected for engineering purposes. This led to the design of instruments which would operate in boreholes, combining the advantages of a reduced size and a deeper investigation, from the surface to several tens of feet. BOREHOLE DEFORMABILITY MEASURING INSTRUMENTS In the last 10 to 15 years, a number of testing devices have been con- structed which can be inserted into a borehole to apply a load and mea-

Jan 1, 1972

APPROXIMATELY 3500 people thronged the Hotel Statler from February 18 to 24 for the 173rd general meeting of AIME. It was a technical extravaganza in that 82 technical sessions were held, at which 500 authors presented some 350 papers. Fortunately, Jerry Peirce, outgoing President, didn't have, to preside at all the events although after his year's stint as President, he has more than a nodding acquaintance with some of the latest problems in the mining, metals, and petroleum industries. Although the Welcoming Luncheon on Monday noon was the official opening of the meeting, Local Section Delegates and the Board of Directors convened on Saturday and Sunday, respectively. The large attendance and business like demeanor of these two groups was in accord with the energetic and competent service they have rendered the Institute through the year. To the applause of engineers and their wives who thronged the grand ballroom of the Statler for the Welcoming Luncheon, President Peirce introduced Oliver B. Hopkins, president of the Canadian Institute of Mining and Metallurgy and C. Gerow, secretary of CIM. Dr. Hopkins brought greetings from the CIM and expressed his satisfaction in the splendid spirit of cooperation that exists between the two Institutes. Dr. Hopkins is president, Interprovincial Pipe Line Co., Toronto, and counts as a close personal friend M. L. Haider, who is the 1952 President of AIME and lately of Toronto where he was a director and general manager of Imperial Oil Ltd. Mr. Haider will be known shortly as Mike to thousands of AIME members as he makes his Local Sections presidential tour. There was a pause in luncheon proceedings when Judge Harold R. Medina arrived amid the applause of the audience and somewhat breathless from his trip via motorcade from an antitrust trial against investment bankers at the courthouse downtown. With the Judge at his elbow, President Peirce took the opportunity in his introduction to good humoredly chide the Judge for the vixenish habits of public servants in their treatment of astute businessmen. The successful inventor who patents his inventions is a monopoly; the copper manufacturer who buys his competitors a drink is in collusion; but the business failure need only look to the government for a subsidy, Mr. Peirce pointed out. Judge Medina, quickly captured the admiration of his listeners. He spoke about justice, deploring partisan deals on nominations for judge-

Jan 1, 1952

By William C. Marshall, Frank G. Norris

THE term "total operation" is meant to include problems that cannot be answered from the standpoint of either the blast furnace or the open hearth separately but must be studied by considering the interrelations of these two processes. There are other ways of expressing this idea, such as reference to the blast furnace and the open hearth as an integrated process or by emphasizing the interrelation and interaction of the two processes. Much progress has been made in metallurgy and other fields by breaking complicated processes and reactions into simpler parts and studying each of these intensively. This intensive study frequently is done under the controlled conditions of the laboratory experiment. The entire process is understood better by this specialized study of each of its parts. This procedure is so satisfactory that an understanding of unit operations is a fundamental requirement of chemical engineering. Much discussion of the open-hearth process is in terms of one heat or one furnace. By this is meant that the conclusions apply to one furnace, wherever it may be. Furnaces seldom occur singly; they are located in groups and these groups are located in steel plants having characteristic blast-furnace equipment. Problems that are affected by the number of furnaces operating, by the number of blast furnaces in the plant and by the fact that the open hearth shop is dependent on the blast-furnace capacity rather than on its own needs for the amount of iron available are among those which, in contrast to "unit operations," we have chosen to call "total operations," Many of these problems, such as charging delays and the general mechanical problem of material handling, are so familiar that merely to define "total operations" brings them to mind. These problems are of such importance that already they have received careful thought and study and probably will merit further study. As will be shown later, these mechanical problems are so intimately related to metallurgical problems of total operations that the effect of certain changes cannot be ascribed with certainty to either a mechanical or a metallurgical cause entirely. Although the problems coming under the general term of "railroading" are included in the problems of total operations, two others are selected for the discussion of this paper. One of these is strictly a problem of composition; the other is strictly a problem of tonnage production. The problem of phosphorus is present whenever basic open-hearth slag is used in the blast-furnace burden. This practice has not secured universal acceptance chiefly because of difference in preference for high-manganese or low-manganese pig iron. If high-manganese (2.00 per cent) iron is to be made, open-hearth slag as a source of manganese is usually cheaper than man

Jan 1, 1943

By G. W. Preckshot, N. G. DeLisle, C. E. Cottrell, D. L. Katz

MOST crude oils contain asphaltic substances that may be naturally or artificially precipitated. In the Greeley field, California, this asphaltic bitumen is precipitated during the flow of the oil from the reservoir to the stock tank. The mechanism of such precipitation is not well understood. This paper presents the progress that has been made by using the electron microscope as a new tool and by observing the effects of the streaming potential on the formation of bitumen particles. Crude oils at atmospheric pressure viewed in the electron microscope in very thin films under a vacuum showed no asphaltic particles. A technique of preparing slides of thin films by dilution of the oil with benzene and washing in petroleum ether was used at first, and these observations showed that the solvents caused the formation of the particles, varying from 0.01 to 0.2 micron in diameter. The electrical effects of fluids flowing through porous solid were studied, with emphasis on the formation of colloidal particles by the streaming potential. The streaming potential of crude oil flowing through sand was measured and was shown to be responsible for the formation of bitumen particles. These results bring out a new phenomenon, which may occur when crude oil flows through the porous oil reservoir.

Jan 1, 1942

By Wayne A. McCurdy

For the third consecutive year, predicted increases in coal production and consumption failed to materialize. Production of bituminous, sub-bituminous and lignite coal for 1961 was estimated by the U.S. Bureau of Mines at 400 million tons, a drop of 15,- 512,000 tons from the 1960 figure. Anthracite production for the year was 17.8 million tons compared to 18.8 million tons produced in 1960. Consumption figures are expected to show a proportionate decline. Of coal's major markets, only electric utilities showed an increase-and even here the increase of approximately 2% was smaller than had been expected. Major cause of relatively low consumption was a decrease of more than 20% in the use of metallurgical coal for making coke. Reductions of lesser importance were registered in general industrial, retail, and export markets.

Jan 2, 1962

By Stuart Buckley

THE application of hydrocarbon equilibrium data to various problems encountered in refining and in natural gasoline recovery is an old and well established practice. Both generalized data and data on specific hydro-carbon systems have been made available by a number of investigators. More recently such data have been applied to the relations governing the separation of oil and gas both in the reservoir and at the surface. Most of the applications to production problems, however, have been based upon examinations of surface samples of oil and gas. This paper describes a technique that has been used satisfactorily in a number of cases to calculate directly from the hydrocarbon analysis of and auxiliary laboratory data on a subsurface sample of the reservoir fluid the behavior of the oil and gas during the various stages of separation at the surface incident to production.

Jan 1, 1938

V. R. GARFIAS,* Palo Alto, Cal. (written discussion?).-Regarding the statement of Mr. Ordoñez, on page 1007, concerning the synclinal curving of sedimentary beds caused by the extrusion of volcanic necks, that "this phenomenon might occur, but it is not fully proved in our fields," I beg to reply that the funnel and anticlinal-ring structure is actually associated with igneous intrusions in the Mexican oil fields, as we were able to ascertain by plotting an underground contour map and making a structural model of the oil-bearing beds of the Ebano field. E. DE GOLFER, New York, N. Y. (written discussion?).-The paper under discussion is not only of interest in connection with its subject but it is a contribution of considerable importance to our knowledge of the possible effect of igneous rocks upon the accumulation of petroleum in the Mexican fields.

Jan 10, 1918

By Dever Ashmead

ANTHRACITE was first mined in the Wyoming Valley and sold as an article of commerce in 1808. As some preparation has always been necessary to make it ready to burn, the preparation of anthracite must date back over a hundred years. Two vital factors have determined to a large extent the degree and method of anthracite preparation. These are, first, the character of the beds worked and the methods by which they were mined and, second, the equipment used and practices followed in the burning of the coal. It is not the intention here to go deeply into these phases of preparation as a paper of no mean length could be prepared on the history of either. Rather, the intention here is to point out the main considerations and to show the influence they have exerted on the preparation of anthracite. MINING METHODS AND THEIR RELATION TO PREPARATION In the beginning f the nineteenth century, the coal beds were virgin with the possible exception of some outcroppings that had been worked, to a slight extent, by the Indians. It is known that the American aborigines had a knowledge of the use of this fuel, because when the Wyoming Valley was purchased from them, in 1754, they mentioned the fact that, by selling the land, they would lose their coal.

Jan 9, 1921

By A. D. Kennedy

No major breakthroughs in concentration technology were made during the year, but solid advances were made in engineering. Perhaps the most significant was the growing acceptance of the unified or "systems approach" to mineral extraction, processing, refining, transportation and marketing. Under the systems approach, transportation is no longer some- one else's business, but a high cost item within the planning engineer's purview. The Savage River pipeline 1,2 and the Marconaflo process3,4 for land and ocean transport of iron ore slurry, are examples showing that evaluation of transportation as part of a unitized system can lead to innovation, and the determination of the physical location of some of the operations. There is even speculation that the cost reductions possible by ocean transport of iron ore slurry may bring in more plants using direct-reduction steelmaking processes.4 Some perennial problems can be solved by application of the systems approach; for example, under this concept the replacement of three small shovels in the pit with two larger shovels is not permissible on the basis of lower operating costs; the resulting change in ore blending upon metallurgical performance must first be evaluated to prove whether or not the change is economically beneficial to the entire operation (perhaps new storage-blending facilities will be indicated).

Jan 1, 1970

At a time when Congressional stiffening of health and safety regulations in the nation's coal mines seems all but an afterthought, when the problems confronting both mine operator and worker are being tossed about like a pigskin in an Australian- rules football match, what could be more appropriate to the times than to incorporate a discussion on these matters into the proceedings of an annual coal meeting. Integration of both technical and topical discussion provided the strength for this 28th Annual Meeting of the Central Appalachian Section of the AIME, convened at the The Greenbrier, White. Sulphur Springs. W. Va., Oct. 31-Nov. 1. Three technical sessions prepared for the occasion were served to those in attendance. First of these was held on Friday morning. Rendered excellent coverage, topics included Roof Structure Analysis at Blacksville No. I, presented by David Eyer, Christopher Coal Co.; Methane Monitors (evolution and evaluation of present day detection equipment); and Instantaneous Control Reaction to Mine Fires and Explosions, in which Elmer A. Fike illustrated the point quite vividly by showing a film on the potential of such control equipment. Indeed, the ability to snuff out a mine fire before it is allowed to spread even beyond its own igniting sparks speaks very well for itself. However, Fike hastened to point out that certain difficulties had to be overcome before these "fire watchers" could be implemented successfully in mines. These "bugs," inherent in virtually all coal mining environments, include ignition of sulfur pockets on mine facings and delivery of sparks on trolley rails, both of which may impede the accuracy of such control monitors.

Jan 12, 1969

By Robert L. Thoms, Richard M. Gehle

Hydraulic fracturing is of considerable interest as a possible release mechanism during operation of storage caverns in salt formations. However, field data are lacking on fluid pressures required to initiate and propagate fractures over a range of depth in U.S. salt domes. A currently active research project is outlined which has the objectives of gathering field data on hydrofracture gradients in inland and coastal domes of the Gulf Coast. A wireline minifracturing system with downhole microprocessor controls is briefly described.

Jan 1, 1985

By R. H. Foley

It is difficult to consider any seam as unsuitable for longwall mining operation for something like 95% of British coal is produced by this system. The following is a brief report on how they do it-their techniques and equipment. Depth of working in British mines varies from about 150 ft to more than 3000 ft, with the average being about 1300 ft. Average seam thickness is approximately 40 in., but working seams vary from 16 in. to as much as 14 ft.

Jan 8, 1965

By D. E. Pickett, E. G. Joe

In accordance with good industrial practice, Canadian metallic-ore concentration plants have always recycled a high proportion of process water to save reagents, save power, conserve water resources, and to protect the community water supplies, to give only a few reasons. In the last few years there has been awakened public concern for the environment and, consequently, government regulations have been added as additional reasons. Present recycling practices are summarized as a basis for improved plant design and operating procedures and for further research. In addition, an attempt is made to determine why plants do not recycle water in certain situations. Although not all Canadian mills are covered, the many examples given indicate the problems and the effort being made to solve them. Wherever available, the chemical quality of the water and the process requirements are indicated as well as the other parameters affecting water recycling at each operation.

Jan 1, 1975