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Before hostilities between the colonies and Great Britain began in 1775, most of the coal used in the northern colonies undoubtedly came from England, with some supplies for New England coming from Nova Scotia; in New York and Philadelphia the supply came from England with some from the Virginia mines. Table 4 shows data obtained from the Public Records Office, London, for the years 1768-1772. This table supplements Table 3, which records only a few shipments from Richmond in 1768 and 1769; as there was no coal shown in imports coastwise in 1769 in Table 4, and only two small shipments in 1769 in Table 3, there may have been a cessation of shipments then, for some reason not now known. In Table 5 are incorporated all the data in the first two, with a few earlier years, and an attempt is made to estimate the amount used during the period by allowing for coal exported. With the small total tonnages a carryover from one year to another makes a large difference in the annual figures, but over the period the result may be fairly indicative of the amount of coal used before the Revolution. According to present day ideas the quantity of coal used during that war was very small, but apparently it was badly needed for the manufacture of the small amount of munitions made in those troublous days. As Philadelphia was the leading city along the Atlantic coast, and as the southeastern part of Pennsylvania was the leader in making iron, as well as making rifles, it is natural that the first call for coal came from there. At first, procuring supplies such as coal, powder and sulphur was handled by a Committee of Safety, which later became a Council of Safety and later this committee's functions were turned over to a Board of War, functioning with the military organization of the colony. . The organizations of the several colonies were slightly different, but Pennsylvania, Maryland and Virginia followed this scheme generally. Later in the war the Congress began to make arms for the troops, and it is difficult now, with the few records available, to tell when the state functions ceased and those of Congress began. On December 5th, 1775, the Committee of Safety

Jan 1, 1942

By Ravindra M. Chhatre

Uranium associated with phosphate deposits has been the subject of numerous investigations (1-8). In the land-pebble phosphate deposits of central Florida, uranium is found in the phosphate matrix (ore) and in the leached zone between the over-burden and matrix (1). Between 0.01 to 0.02 percent uranium is found in the leached zone, which consists of apatite and aluminum phosphate minerals (crandallite, wavellite, millisite) (Z). The primary phosphate mineral in the matrix is apatite, and the 0.005 to 0.01 percent uranium typically found in the matrix is associated with this mineral (1). It is generally believed that uranium substitutes for calcium in the apatite structure (3-5). Clay and quartz phases associated with phosphate deposits contain little uranium (1, 6), and no descrete uranium minerals have been detected in these deposits (4). A typical phosphate matrix consists of quartz, slimes (-150 mesh material) and recoverable phosphate. When the matrix is beneficiated, partition of uranium and radium takes place (9, 10). Although considerable data exists on how uranium is distributed in the phosphate deposits, no systematic study has recently been reported on the distribution of uranium during phosphate rock beneficiation. The purpose of this study was to determine how uranium is distributed in the various strata which comprise the overall land-pebble phosphate deposits, as well as how the uranium is redistributed during beneficiation of phosphate matrix. To obtain this information studies were carried out on matrix samples obtained from three different mines in central Florida. Using pilot-plant scale beneficiation, an analysis was performed on how uranium in the matrix is distributed among the pebble fractions, flotation concentrates, flotation tails, and slimes. The uranium level profile for an active mining area was also obtained. Also, since thousands of acres of slime ponds may someday become a source of both phosphate and uranium, a depth versus uranium content profile was determined for an inactive slime pond.

Jan 1, 1978

By Dever Ashmead

ENGINEERS, operators, miners, and others di-rectly interested in mining will readily agree that more of well-directed illumination in mines will result in a reduction of accidents and general im-provement in the working conditions, comfort, and effi-ciency of those employed underground. Progress has been made in the amount of illumination from individual lamps carried by miners. The candle, which a great many of us can remember as the general method of lighting, was replaced by the oil lamp or torch, later by a specially prepared oil known as "Sunshine," and eventually by the carbide cap lamp. The metal mines still present a field for progress from the standpoint of general illumination, particular-ly those mines having high stopes. Attention is being more and more focussed upon the advantages of im-proved lighting in mines, in order that the underground employee may benefit as the factory workers have al-ready done. The management is vitally interested in the morale of its employees, the reduction of costly accidents and increased production, all of which, judging by results in other industries, will be sub-stantially benefitted through the means of improved general illumination. From data available to the writer, 40 to 50 per cent of the accidents in the metal mines occur at the face; they may be due to roof falls, movement of loose ore, loading of cans, handling of tools, etc. Very probably a large proportion of these accidents may be attributed to lack of light. If sufficient illumination had been present the employee could have seen what was happen-ing and taken the proper precautions. The introduc-tion of better illumination means better visibility, de-crease in accidents, and increase in efficiency.

Jan 6, 1928

By Gordon T. McKenna

"Syncrude Canada Ltd. is developing new concepts in lease-closure landscape design for its Oil Sands Leases 17 and 22 in northeastern Alberta. Closure planning is becoming an integral part of the planning cycles and of the lease operation. By incorporating closure planning into the day-to-day operation, the company will achieve acceptable lease closure in an economical manner. Ultimately, Syncrude will achieve lower operating costs through innovation in mine planning and a reduction in residual liabilities.New concepts being evaluated for lease-closure landscape design include: designing for closure, use of landforms and natural analogs, self-armouring bouldery ground, robustness in design, landform grading, terrain analysis of reclaimed land, geotechnical hazard assessments, choices in closure design timeframes, passive maintenance, determining post-closure monitoring goals, engineering tailings, engineering other substrates, use of test plots and field demonstrations, geomorphologic monitoring of reclaimed lands, defining closure goals, and visiting other mines. These concepts are being formalized under the new discipline of Landscape Engineering."

Jan 1, 1996

By C. H. Mathewson

ABOUT fifty pages of Henry M. Howe's profound treatise, "The Metallography of Steel and Cast Iron," are devoted to twinning with special reference to the origin, nature and general significance of the Neu-mann bands in ferrite. Howe believed with Osmond and Cartaud1 that the Neumanns are mechanical twins and his careful observations leave no doubt that these straight-sided narrow bands habitually occur parallel to trapezohedral planes of form {211}. Attempts to develop the structure of the bands by various methods so that their identity could be established beyond question have not been conspicuously successful. Howe thought that they deflected slip bands. Some of the etching figures which have been developed within and adjacent to Neumann bands support the contention that they are twins. A good example of this effect in ferrite containing 0.6 per cent. of nickel and 1.3 per cent. of phosphorus, originally due to Harnecker and Rassow,2. was reproduced in the 1928 lecture before the Institute of Metals Division on twinning in metals.3 In this case, the sides of the figures might represent the traces of cubic planes laid bare by etching a properly oriented grain of ferrite, twinned along a plane of form 12111. Our own observations in this direction may be represented by Fig. 1 which shows in a deeply etched cavity in the boundary region between a Neumann band and the original crystal two small crystal surfaces which resemble the faces meeting at a reentrant angle in the simple cube twinned along a bisecting plane of form {211} as sketched in Fig. 2. Rosenhain and McMinn4 in 1925, after a careful study of slip bands in ferrite containing Neumanns previously produced by shock, concluded

Jan 1, 1928

By Oliver Bowles

STRIKING new developments in the field of industrial minerals include the employment of lime, salt, coal, and air for the manufacture of stockings, and the substitution of paper for granite and marble in making tombstones. Certain minerals that have heretofore been regarded as valueless except as museum or laboratory specimens, are now being applied commercially. Serpentine, in forms neither fibrous nor ornamental, massive topaz, pinite, and zoisite are examples. For certain other minerals, notably pyrophyllite, bentonite, vermiculite, and sulphur, extension of established uses into new fields has occurred. Substitution takes a toll in many industries, but producers of industrial minerals as a class have gained more than they have lost in recent years. Encouraging progress has been made in developing at long last a suitable substitute for certain of the uses of mica, the only industrial mineral on the strategic list of commodities established by the War. and Navy Munitions Board. Some of the more important developments in process, equipment, and use .that have come

Jan 1, 1940

By Dave Weymer

Falling timber in BC has always been a hazardous job. Huge, often rotting trees and steep, rugged terrain combine to create difficult and dangerous conditions. Death and injury rates are among the highest of any occupation in North America. In BC, the men that head out, saw in hand, are called fallers.

Jan 1, 2013

The optimum situation in sealing the soil with latex would be to locate the sealant at the depth where natural permeability is lowest, and to narrow distribution of the latex to a film. To ascertain how closely we were achieving these objectives it was necessary to devise a method to measure the concentration of latex in soil. A number of methods were explored and two were used in actual field tests. SBR latex tagged with c14 was prepared and used to determine the distribution of polymer in the soil. The latex was made by copolymerizing a mixture of radioactive and normal styrene with butadiene in bottles by conventional methods. Average particle size was 600 Å. Diluted aliquots had 1.40 microcuries radioactivity per gram of latex. Tagged latex was mixed with soil in a range of proportions from 0.01 to 0.25% by weight to develop a calibration curve. Analyses of soil in the laboratory and from the field were determined by comparison with this master curve. Styrene-containing polymers have a characteristic peak at 700 cm-1 but crosslinked SBR is not soluble in solvents normally used in infra-red spectroscopy, e.g., carbon disulfide. We developed a method for solubilizing the crosslinked polymer by stirring overnight at room temperature a soil sample in chloroform with t-butyl hydroperoxide and osmium tetroxide. The filtered chloroform residue was dried to constant weight, thoroughly mixed and pressed into a KBr pellet, and concentration was determined by measuring the absorption at 700 cm-1. Details are given in an Appendix.

Jan 1, 1972

By G. M. Ellis

This paper deals with some aspects of concrete construction in remote locations and/or cold climates. The writer's experience covers 25 years in construction in western and Central Canada. I will bring forth some pertinent observations and cost facts learned from this experience. Let us start by saying that there is nothing more important than preplanning the entire project. By this I mean the production of the engineering design, working drawings, soliciting of prices and ordering of all equipment and contractors work, the delivery of all equipment and all onsite work. All of this should be placed on a master schedule, preferably a C.P.M. We have been using C.P M. Scheduling for all of our work for 5 years and have found it in-valuable. This preliminary schedule will show initial items of work and target dates. After main equipment orders are placed and deliveries confirmed, the construction schedule can be revised to include manpower and construction equipment requirements. From this information the size of camp is determined. This, of course, must be ordered several months ahead. The manpower schedule can be broken into trades to tell us the number of men of each trade required at any time. This is important in helping to determine where the men must come from and whether or not any incentive is needed to get them. The schedule will also point out if it is impossible to get the project closed in before winter becomes too severe unless overtime is worked or the project is started in early spring. In most parts of Canada cold weather starts in October and lasts through April. A common term of reference has been to wait for the frost to come out of the ground before starting work in the spring. In some areas this can be as late as June. The construct-

Jan 1, 1971

By Donald A. Dahlstrom

In 1961 it became increasingly more evident that significant technological changes must be made in minerals beneficiation. The status quo in technology in today's competitive markets will not be tolerated. Higher productivity, greater recoveries and newer and better products must be sought and incorporated with lower operating costs. In other words, "when you build a new mill, don't build an old mill." Recommended reading for proof of the vital necessity of new methods and techniques is in the September 1961 issue of MINING ENGINEERING. The article by one of MBD's cherished and true veterans, E. H. Rose, is entitled "Iron Ore: The BIG Picture". Because of new beneficiation methods for iron ores, nearly 47 million tons of plus 60% iron concentrates will be produced and another 40.1 million tons of capacity will be under construction or committed. Thus in a relatively short period, 87 million tons of this high-grade iron concentrate with record low silica will be available. As Mr. Rose also points out, "in gross tons, without allowance for better grade, this is the equivalent of almost exactly two-thirds of all iron ore used for all purposes in the U.S. and Canada in the peak years of 1953 or 1957." Needless to say, improved mineral beneficiation methods have had far more reaching effects than just the production of higher grade iron concentrate.

Jan 2, 1962

By T. G. Edgeworth

Some of the historical background of the industry is reviewed, with reference to the different types of reduction cells in use for aluminum smelting. Factors to be considered in cell des1gn involve capital, power, and operating costs. The trend is apparently toward larger cells. The industry is studying new construction materials for cell linings, as well as alternate electrolyte compositions and other design changes which will improve productivity and energy efficiency. The aluminum smelting activity in other countries is briefly reviewed. TODA Y'S industrial production of aluminum is still based on the simultaneous discoveries made in 1886 by Charles Martin Hall in Ohio, and Paul Heroult in France. Up to that date, only about 50 tons of aluminum had been produced in the world, and the price at that time was about $5 per pound. Sucl1 figures must be contrasted with the present world aluminum smelting capacity of over five mil-lion tons per year, and a price of about 25 cents per pound.

Jan 1, 1962

FOR some years past it has been usual to specify high-grade copper for use for many purposes, but the practice of specifying zinc of a high degree of purity for certain purposes is of comparatively recent origin. It is a practice, however, which is extending ag the effect of the impurities in zinc on products manufactured therefrom becomes widely recognized.The notes hereunder are intended to briefly survey the principal uses to which high-gr.ade zinc is being put, and, wherever possible, to indicate the effect of the impurities normally present in the lower grades of zinc.In the United States zinc is graded into five divisions, known respectively as "High-grade" "Intermediate" "Brass Special" "Selected," and "Prime Western." The maximum amounts of impurities allowed in the various grades are indicated in Table I,which is compiled from data published by the American Society of Testing Materials:In addition, it is specified in an cases that the slabs shall be reasonably free from surface corrosion or adhering foreign matter. Although zinc used in Europe has in many cases been sold on analysis it is only recently that any attempt has been made to grade...

Jan 1, 1923

By C. P. Hood

"The amount of ash in anthracite coal interests every buyer, and occasionally produces caustic comment, but there is a lack of authentic figures that will take the subject out of the realm of opinion and agitated fancy and. give a true picture of the quality of coal actually delivered. What per cent ash is to be expected when the coal is good, and when have we a right to make serious complaint?During the past summer the Bureau of Mines took 127 samples of 1000 pounds each, representing nearly 30,000 tons of anthracite is dealers' yards in seventeen cities in the State of Massachusetts. There were three objects in view, to discover the average and the variation in amount of ash in anthracite in some easily described area; to demonstrate standard sampling methods, and to learn something about the feasibility of itinerant coal sampling. Massachusetts was selected because its principal cities could be visited in a single season. There also appeared need for demonstration of standard sampling of coal, since a coal quality law had been passed in the State, to be administered by those unfamiliar with coal sampling."

Feb 1, 1924

By Oldrich Machacek

Seismic explosives are very important tools in the search for oil and gas. Changes and new techniques in seismic exploration methods are also demanding new developments in seismic explosives. This article concentrates on three problems, characteristics of surface seismic explosives,causes of fires in application of surface seismic explosives and new developments in downhole seismic explosives.

Jan 1, 1985

By Robert D. Lonqyear

SOMEWHAT biased by pride in twentieth century achievements, most of us mining engineers and diamond-drill operators look upon core drilling as a relatively modern practice. The invention of the diamond drill is generally ascribed to Rudolf Leschot, who made use of diamonds in 1846 in drilling blast holes in the Mont Cenis tunnel in Switzerland. In vain we search Agricola and other early writers on mining for signs of diamond drilling. We have, therefore, concluded that it was unknown until the middle of the last century. The trouble with this conclusion, as most prospectors will tell us, is that we "don't dig deep enough"; for it now appears that the archeologists have been putting one over on us for the last fifty years.

Jan 1, 1936

By C. H. Noren

For some years the Du Pont Company has utilized computer calculations to study the various theoretical properties of explosives. These studies have yielded valuable information on the effects of density changes or formulation changes on detonation rate, detonation pressure, explosion pressure, heat of explosion and numerous other properties, and have aided in evaluating the theoretical potential of explosives. In addition, a multitude of laboratory tests have been utilized for the evaluation of explosives. When comparing the computer data and the voluminous test data it became evident that numerous anomalies existed. Tests in rock were required to study explosives under borehole confinement. This fact was further emphasized after numerous field measurements showed that the borehole velocity of commercial explosives did not match the theoretical value but was dependent on conditions of field use. Since we are interested in the practical aspects of blasting, a program was initiated to evaluate explosives as used in commercial blasting. INSTRUMENTATION Most of you are familiar with the extensive work that has been done by the U. S. Bureau of Mines in their studies of strain measurements in rock. Early in our work we adopted procedures similar to those used by the Bureau of Mines. Strain pulses were measured by gages cemented in boreholes. Since we were primarily interested in the effect of explosives in the zone where fracture might occur, this system offered several disadvantages for Du Pont: 1. Cemented gages were expensive and not reusable. 2. When gage holes were used for several shots, there was considerable question as to the condition of the rock after the first shot.

Jan 1, 1968

By W. T. Isbell

IN the Parkes process of lead refining, after desilverization has been completed by means of the addition of zinc, there remains in the lead from 0.5 to 0.6 pct zinc. At this stage in the refining operations virtually all impurities are reduced to refined lead specifications except zinc and antimony. All excess copper, nickel and cobalt have been removed by the zinc additions. The silver remaining should not exceed 0.1 oz per ton. It then remains only to remove the zinc and antimony in order to produce refined lead. At the Herculaneum plant of the St. Joseph Lead Co., practice formerly was to complete the refining by means of oxidation in a reverberatory furnace. This process consisted of heating the lead to 14000 to 1500°F and allowing it to come in contact with excess air passing over the surface of the lead and periodically agitating the bath of lead with air. This procedure not only resulted in the loss of zinc but of a considerable quantity of lead converted to the oxide in the form of dross and fume. The fume, collected in the baghouse, together with the dross was returned to the blast furnace, thus adding appreciably to the circulating load on the blast furnace and refinery. In addition, operation and maintenance of the reverberatory furnace was expensive and required the performance of disagreeably hot and somewhat hazardous work. The process of dezincing with high vacuum was developed at this plant as a substitute for the oxidation process and finally led to lower operating costs, the practical elimination of dross and fume and the direct production of metallic zinc, which is very suitable for re-use in the desilverization process. Essentially this process consists of subjecting the lead to high vacuum, in a kettle provided with means for heating, a bell-shaped member open at the lower end so constructed that it can be immersed in the molten lead, and means for evacuating the interior of the bell and for sealing an agitator. Metallic zinc is thus produced and collects on the upper cooled part of the bell member. This metallic zinc is periodically removed and re-used in the desilverization process. The process is quite simple. It is conducted at a low temperature, thus permitting the use of iron equipment, and shows a material saving in refining costs over the old method. EQUIPMENT AND ITS USES Dezincing Machine.-The equipment employed in this process consists of a dezincing machine, a steel kettle of 120 tons capacity, a vacuum system and equipment for handling the dezincing machine (Fig I). The dezincing machine consists of a compact assembly, suitable for handling with an overhead crane, consisting of a treating chamber and the agitating mechanism. Treating Chamber.-The treating cham¬ber is a bell-shaped shell (4), similar in shape to a hemispherical kettle with a lid

Jan 1, 1947

By Robert B. Parsons

"It is generally acknowledged that Canadian and foreign-based mining companies are spending relatively fewer dollars in Canada and more dollars abroad than was the case not many years ago. It is common to see the Canadian tax system being fingered as one of the causes in this shift in direction. However, if one takes the time to peel away the surface of our tax system, and to probe a little deeper into its substance, it will be found that the Canadian taxation of mining is generally quite competitive. IntroductionCross-border shopping in the mining industry? - Absolutely! Economics 100 teaches that dollars are votes in the capitalist system, and mining companies are going to cast their limited number of votes where they can achieve the highest return at the least risk. The Canadian consumer knows that taxes are a major factor in cross-border shopping, and mining company executives know that the same tenet holds true in their industry. Unfortunately, mining operations are subject to such a bewildering array of tax rules that making an intelligent decision is not always an easy matter.Statutory Tax RatesConsider, for example, the ""statutory"" tax rates shown in Table 1. (Statutory tax rate in this table refers to the simple sum of federal and provincial tax rates on profits as specified in the tax legislation.) Looking only at the total statutory tax rates (such as 66070 for Manitoba) , one might quickly observe that the Canadian mining industry is subject to a truly onerous tax regime, especially as compared to the United States where statutory tax rates can be in the 34% range."

Jan 1, 1992

By David White

THE search for potash salts in the great "Red Beds? region of the Southwest, conducted for several years by the U. S. Geological Survey, the work being carried on for a part of the time in coöperation with the Bureau of Economic Geology and Technology of the University of Texas, has resulted in the discovery, within shafting depth, of potash salts, apparently of workable thickness and commercial quality, and prob-ably of great extent. Definite information is lacking as to the exact thickness of the potash beds, the size and boundaries of the areas underlain by workable strata, and the locations of the deposits richest and most favorably situated for exploitation. Briefly to review the salient features, of the general situation: We have in the great Red Beds region of the southwestern United States, embracing portions of central Kansas, western Oklahoma, eastern New Mexico, and northern and western Texas, .a series of sandstones. shales, anhydrite beds, clays and limestones, which; through an interval of 1000 ft., more or less, carry beds of salt, estimated by Darton1 to contain over 30,000 billions of tons of rock salt. It is the greatest known salt field of the world. At some points the intercalated beds of rock salt, one of which is reported by the driller to exceed 300 ft. in thickness, aggregate, accord-ing to the drillers' records, over 1000 ft. The sedi-mentary strata are similar in composition to those carrying the potash deposits of western Europe, and they were laid down at the same time and under condi-tions which, in many respects at least, were similar The stratigraphy and character of the beds are des-cribed by Darton2 and a, part of the area and the reported aggregate thicknesses of salt are shown, with some revision after Darton, in the accompanying map Fig. 1. The assumption that in the great areas of shallow evaporation basins spread over -the vast base-level region of saline deposition in the Southwest during Permo-Triassic time, potash salts were in some places, and at different stages, thrown down in crystalline deposits associated with the beds of rock salt, anhydrite, and gypsum, is, geologically speaking, more than reason-able. They are to be expected, and the conviction that they are probably present has long been held both in the Texas Bureau of Economic Geology and Tech-nology, under Dr. J. A. Udden, and in the- U. S. Geological Survey. Accordingly, for many years, efforts to determine whether potash deposits are present in this region have been made, though under very great difficulties, such as insufficient funds for boring, hack of drilling on private initiative in the more promising regions, hack of interest at first on the part of the drillers and companies, and, hater, inadequacy both of the methods of boring and of the sampling, to reveal in definite terms the thickness-of any saline stratum of given composition.

Jan 4, 1922

By Robert B. Parsons

"1984 was an eventful year in the courthouse f or observers 0/ the mining tax scene in Canada. For the first time in a number of years, the Federal Court heard several important tax cases which pertain directly to the resource industries. Tax Notes discusses/our cases that could affect the taxation 0/ operations and investment in the mining sector.Capital Gain or Income?Ever since tax reform, risk-takers in the exploration business have maintained that the taxation of capital gain s is a significant impediment to raising risk capital. It must be akin to rubbing salt in the wound, then, when an entrepreneur sells shares and the Court upholds Revenue Ca nada taxing the gain as ordinary income instead of capital gain. But, this is precisely what happened in the case of The Estate of Murray Watts, et al. v. The Queen.The issue that had to be decided by the Federal Court, Tri al Division, in this case was whether or not the profit from the sale of shares in Hearne Coppermine Exploration s Limited in 1968 was a capital gain, or income subject to tax.Hearne was incorporated in July, 1967. At that time, the three plaintiff s, together with seven other individuals, subscribed for 400,000 shares at 10 a share. The plaintiff subsequently subscribed for an additional 500,000 shares at $1.A pooling agreement was entered into by all ten shareholders regulating the disposition of any o f their shares; any sale required approval of seven of the ten initial sub scribers. It also provided for the sale of their shares 30 days after any public offering."

Jan 1, 1985