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By J. P. Dunlop

THE fact is notable though probably little known that the United States is the only nation obtaining and distributing through its Government bureaus any data pertaining to waste metals and drosses. Some foreign governments do issue reports relating to mine or smelter production of primary metals, but none gives in scope and detail the information published now by the U. S. Bureau of Mines and formerly by the U. S. Geological Survey; and this is despite the fact that the funds annually allotted for those purposes are insignificant in comparison with allotments for the preparation of data relating to other industries of like importance. The earliest data on the production of metals from secondary sources in the United. States were contained in a press bulletin issued by the U. S. Geological Survey on Jan. 4, 1909. The information published was that for the year 1907 obtained and compiled by C. E. Siebenthal, who was one of the first to visualize the growing importance of the scrap-metal industry. The National Conservation Commission had emphasized its opinion that the known domestic supply of certain kinds of the more important metals was being rapidly marketed and that while there was no immediate cause for concern it was best to conserve such resources. Not only had there been a lamentable lack of any data regarding the quantity of scrap metals available or used but also gross carelessness and indifference in the segregation, collection, and effective use of scrap material. Siebenthal realized that even approximately correct statistics of recoveries from the more important base-metal scrap and drosses were nearly as essential to both producers and consumers as the statistics of the output of primary metals. There were not then nor are there now sufficient funds for complete collection of data, nor was it considered the province of the Geological Survey to do more than determine approximately the recovery of secondary metals for use in supplementing those given for the primary metals. Undoubtedly the first bulletins issued did not give the full output, for it takes time to establish contacts for an inquiry covering so

Jan 1, 1928

"The largest variety of asphalt and related bitumen deposits in this country is found in Utah. Utah is one of the few places in the world where the hydrocarbon minerals, gilsonite or uintaite, wurtzilite (trade name elaterite) and ozokerite are produced. These bitumens occur in an area embracing nearly 10,000 square miles in eastern Utah near the Colorado line. This area is largely in the western part of the Uintah basin. The bitumens are in the Tertiary horizon in the various divisions of the Eocene series.Gilsonite is an asphaltite derived from petroleum, wurtzilite is an asphaltic pyrobitu¬men derived from petroleum, and ozokerite is a native mineral wax resulting from the met-amorphosis of paraffinaceous petroleum.Gilsonite is produced by the Gilson Asphaltum Company, a subsidiary of the Bar¬ber Asphalt Company, at Watson, Utah. A narrow guage railroad, seventy miles in length and with a 7 1/2 percent grade over the Book Cliffs on Baxter Pass, was constructed by the company from the Denver & Rio Grande Western railroad main line in order to open up the gilsonite deposits. The veins range from narrow upward to 18 feet in width. The Rainbow vein at the present wokings is eight feet wide, vertical, and has sandstone walls. This vein has been opened up for a distance of about three miles and in some places four hundred feet deep. Forty men usually are employed with a production of eighty tons per day."

Jan 1, 1925

By John Gross

The study of the energy used in crushing operations has advanced from a period of perplexing confusion to one of greater clarity. Only within the last few years has any true conception of the work in crushing been possible, owing to the chaotic state of theoretical knowledge. For some 20 years a controversy existed between those advocating the Rittinger law and those advocating the Kick law. The Kick law now appears to be definitely out of the picture, and crushing efficiency may be based confidently on the Rittinger theory. There also seems to be a generally crystallized conception as to the meaning and nature of sub-sieve material. There is needed a simple, direct method for determining surface on a crushed ore product, and also a simple and accepted method for size determination on minus 400-mesh material. The Crushing Law The Rittinger(l)‡ theory of crushing was advanced in 1867 and the Kick(3) theory in 1885. While the Rittinger theory might have been accepted without much question and actually had been accepted by many investigators, a serious doubt as to its validity was raised by Stadler(10) who upon purely theoretical grounds proclaimed the Kick "law" as the true law of crushing. According to Rittinger the energy required in successive steps in reduction increases geometrically, while according to Kick the energy increases arithmetically. These "laws" therefore are at variance, and the establishment of the true law was recognized as of first importance. Many simple experiments have been made to demonstrate the application of the Rittinger theory to crushing, and it would seem that its simplicity should favor its acceptance. Experimental evidence, however, was not convincing, as no reliable data could be obtained on the finer material from a crushing or grinding operation. Gates,(13) Bell,(19)

Jan 1, 1935

By V. D. Leary, O&apos

Contracts between The Anaconda Co. and its miners at Butte, Mont., are not contracts in the true sense of the word. They are weekly verbal agreements which tacitly admit that the company, on the one hand, will supply the place, the tools, the material, and the opportunity and that the miners, on the other hand, will supply such effective labor that both parties will profit from the arrangement. Prices are seldom discussed at the time of hiring. The miner, in effect, is hired for a definite working place, as a contract miner, and if satisfied, tries to earn as much as he can. If he is not satisfied three courses are open to him: he can quit, he can ask for a change, or he can discuss prices or improved working conditions with the mine superintendent. This rather informal arrangement is due to conditions that are particular to Butte

Jan 2, 1961

By Howland Bancroft, Louis S. Cates

WE have come a long way since the order of the day was the chance discovery of mineral deposits, breaking rock with fire and water, melting metals in open fires in holes in the ground or in primitive furnaces, digging pits to collect. oil seepages, burning eroded coal outcrops to develop heat, and so on. During the past 5500 years, gradual improvements in methods and equipment have come about, explosives have been developed and used, steel has been used in increasing quantities and effectiveness as its physical and chemical characteristics, and composition have been altered and made to serve specific ends, hand equipment has given way to almost completely mechanized operation Thus, by the aid of mechanical equipment, one person is now able to move several thousand times as much material as one person was able to move a relatively few years ago. When this Institute was formed 75 years ago, the Suez Canal had been open to traffic but three years. It had taken ten years to complete and was built under the direction of French engineers by workers of whom many were girls. During the first four years of construction, these workers dug up the sand with their fingers, threw it into rush baskets, carried the load a hundred feet or so and dumped it 2 (With the termination of forced labor, dredgers completed the digging of the channel.) At the present time there is in use in the United

Jan 1, 1947

By L. H. de Wald, J. Walter Scott

The removal of lead by fire refining methods from copper of electrolytic quality is growing in importance. Particularly is this true of the refining of secondary copper and copper cathodes obtained from electrolytic cells where lead is used as the anode material, as in the electrolysis of ore-leaching solutions and foul electrolyte. When investigating the removal of small amounts of lead from molten copper in a reverberatory furnace during the refining of secondary copper of otherwise electrolytic copper quality,' it was found necessary first to know something about the distribution of the lead throughout the bath. The authors believe that it is not generally known how small amounts of lead as an impurity are distributed in a molten copper bath; that is, whether the lead is concentrated at the bottom or at the top, or whether it occurs more or less uniformly throughout the bath. The data contained in this report may help, therefore, in the development of a satisfactory fire refining method for the removal of this obstinate element from a molten copper bath. The first step was the development of a method for taking samples from various locations in the bath, at the surface and at various depths. The sampling device used, shown in Fig. 1, consisted of a 10-gram fireclay assay crucible fitted into a ring on the end of a steel rod handle of suitable length. A fireclay scorifier, 2 in. dia., with a ½-in. hole bored in the

Jan 1, 1930

By John Johnston

The actual amount of any metal volatilized from a mixture of metals depends on the magnitude of its partial vapor pressure under the specified conditions of temperature, and on the circumstances attending the heating—in particular, on the duration of heating, the volume of gas coming into actual contact with the surface of the metal, the extent of this surface, and the rate of diffusion of the volatile metal from the body of the melt toward the surface.' If two (or more) metals are volatilizing from the same mixture of metals, the several conditions are identical except for the difference in partial pressure and in rate of diffusion of the volatilizing metals; the second of these two factors is without doubt only of secondary importance as it is probable that the rates of diffusion of the volatilizing metals would be very similar. Hence, in order to gain an estimate of the relative amounts of two metals that may be volatilized from a given mixture, it is necessary to know the vapor pressure, or, more precisely, to ascertain for each metal its partial vapor pressure in equilibrium with the liquid (or solid) alloy under the particular circumstances. The partial pressure of each constituent depends on the effective concentration of that constituent in the alloy2 as well as on the vapor pressure of the constituent when pure, and it can be calculated when both of the above factors are known. The first step, therefore, is to ascertain the vapor pressure of the several pure metals. Vapor Pressure of Pure Metals The experimental data on the vapor pressure of the several pure metals with which we are here concerned are not so accurate as could be wished, nor have the determinations been made in general at temperatures such that the results can be used directly. In a previous

Jan 1, 1919

From the cold Pacific waters in June rolls a blanket of white clouds that tucks up around the mountains at around 8000 or 9000 ft. This is the way it happens in southern Peru and so the mining operations and daily living at Toquepala have an ethereal quality not often encountered. Besides looking down on the clouds from the brightly sunlit mountain tops, one can discern the trace of a different era in the brown barren mountain slopes. This trace is like a delicate net laid over the surface of the earth-a criss-crossing of innumerable trails that are so omnipresent, yet faint, that the local people have long since ceased to notice them. It is difficult at first to ask about them because no one understands what you are talking about. It finally comes out though, that the markings are indeed trails, but fossil trails made by animals in times when they were in abundance in a countryside that was green in some bygone century. In a way Toquepala is still pristine, it is the way the engineers planned it-from the ground up. There are no additions or expansions- those tackings-on that spoil the symmetry of design while increasing the profit. This does not deny that annual production has gone up over the years. Daily mill throughput has been increased from 30,000 to 42,000 tpd. Initial design of the concentrator was for 30,000 tpd but in 1964-65 milling capacity was increased to 36,000 tpd at a cost of $3 million.

Jan 11, 1969

By J. J. Donos

IN the operation of a smelter, continuous and accurate determination of smoke losses is essential for purposes of metals inventories and as a check on the efficiency of smoke recovery apparatus. Previous to the development of a continuous and automatic smoke sampler by R. MacMichael, in 1924, two methods were in vogue, and still are in some smelters, for measuring solids passing out of a flue or stack. These are: (1) the so-called dust concentration method whereby the gas volume passing through the flue is first measured and then the total amount of solids carried in the smoke stream calculated from the weight of suspended matter filtered out of a measured volume of gas; (2) the balanced tube method is independent of gas volume flowing through the flue, and relies for its accuracy on the fact that a true smoke sample may be taken if the velocity of the gas in the sampling tube is constantly maintained at a known ratio of the average flue gas velocity. The total amount of solids passing through the flue is then proportional to the weight of filtered solids and to the ratio of the area of the flue to the area of the sampling tube, corrected for the velocity ratio. The limitations of the first method lie in the uncertainty of the varying volume of gas arising from metallurgical operations and the unreliability of ordinary gas meters to hold their accuracy under

Jan 1, 1951

By William K. Callaway

Cominco American has operated the Magmont Mine for 16 years as a traditional open stope room and pillar mine. Diminishing ore reserves and the discovery of high grade ore zones over 90' in thickness caused consideration to be given to hydraulic sandfilling as a method of ground support to increase pillar extraction and mine life. This paper will review the results of sandfill testing. Plans for underground experiments, and operational plans for the future will also be discussed.

Jan 1, 1984

By Charles Cowie

Jan 1, 1985

By C. L. Meyers, J. L. Lytton, T. E. Tietz

The recovery of tensile flow stress of 99.995-pct Al and Al-1 pct Mg alloy was investigated using a fractional recovery parameter. Tensile strainirg was conducted at room temperature, and recovery treatments were made in the range from 80° to 200°C. Equal values of fractional flow stress recovery were found to result in equivalent structural states. Identical recovery treatments were found to produce constant values of fractional flow stress re covery, independent of prestrain. The activation energy for recovery of the 99.995-pct A1 between 80" and 200°C was found to be 23,000 +2000 cal per mole, and the activation energy for the Al-1 pct Mg alloy was 27,500 cal per mole. 1 HE degree of recovery of a cold-worked metal may be studied by measuring the changes which take place in any of a number of properties. Some of the properties which have been used by past investigators include X-ray diffraction phenomena, electrical resistivity, hardness, creep strength, elastic limit, and flow stress. Despite the apparent preponderance of such studies, little is known concerning the effect of recovery on the strength of metals except as deduced from changes in various types of hardness measurements. Furthermore, little information is avail- able concerning the effects which specific solute atoms have on the recovery process. Limited studies have indicated that in some cases solid-solution additions greatly decrease the rate of recovery,' whereas in at least the case of magnesium additions to alluminum an increase in the rate has been reported.2 The purpose of this investigation was to determine the effect of a 1 pct Mg addition on the recovery of high-purity aluminum. Because of the particular interest in the effect of solute additions on the recovery behavior as related to mechanical properties, the degree of recovery was evaluated in terms of tensile flow stress. For the purposes of this study, a recovery process shall be defined as any process, short of recrystallization, whereby the properties, of work-hardened metals tend toward their values ill the unstrained state. EXPERIMENTAL PROCEDURE Test Materials. The materials used in this study were a 99.995-3 A1 and an Al-1 pct Mg alloy made from high-purity base metal. The high-purity aluminum contained the following wt pct impurities: 0.001 pct Cu, 0.002 pct Fe, 0.001 pct Si, and 0.0004 pct Mg. The Pil-1 pct Mg alloy contained 0.001 pct Cu, 0.002 pct Fe, 0.003 pct Si, and 0.99 pct Mg. Both materials were obtained in the form of as-rolled 0.125-in.-thick sheets, from the Alcoa Research Laboratories, New Kensington, Penn. Tensile specimens were cut from these sheets with the longitudinal axis in the rolling direction. Both materials were recrystallized in a molten salt bath; the high-purity aluminum at 450° C for 20 min and

Jan 1, 1962

By A. A. Dor

Of the numerous methods that have been tested or considered for the beneficiation of low-grade iron ores, this article deals only with proven flowsheets that are adopted in plants in operation or which have been reliably pilot-plant tested. Several recommended layouts are described and discussed. They illustrate recent trends and embody improvements and new features that have resulted from the experience acquired in the operation of the plants already in service. They have been developed, in the last few years, in the course of designing several iron ore beneficiation plants of various types and sizes. Some of the design features in the layouts which are submitted represent, in some respects, personal views and may not meet the full approval of others in this field. It is hoped that this presentation will provide an opportunity for constructive discussion of the problems involved and of suitable solutions.

Jan 6, 1962

By N. O. Johnson, R. A. Westin

Polychlorinated biphenyls were the basis of non-flammable askarel dielectric liquids wed in electrical equipment made between 1929 and 1978. Although PCBs were widely used in mine electrical equipment, the toxicity and environmental persistence of this chemical led Congress to ban its manufacture and use. Bureau of Mines Information Circular 8838 summarizes the regulations imposed by the EPA on the use and disposal of PCBs, and describes the limitations of available substitutes. Recent changes in the regulations will impose additional requirements on the use of PCBs by the mining industry. This paper is an update of the material presented in the Bureau of Mines information circular.

Jan 1, 1983

By D. T. MacRoberts

Tins paper embodies the results of theoretical studies concerning gas reservoirs, especially the effect of drilling programs of various intensities upon pressure depletion and ultimate recoveries. The primary objective has been to determine the net quantity of recoverable gas that could be obtained as a result of each additional well, in comparison with the gas that might be secured from a single well ideally placed with respect to both acreage and geological structure. No method is yet known whereby the relative merits of intensive and sparse drilling can be compared experimentally; a reservoir must either be drilled closely or developed with wide spacing, but both programs cannot be conducted simultane-ously. Hence, the analytical method seems to be the only approach to the problem. While the present state of our theoretical knowledge does not offer a precise solution to the problem of gas flow in sand bodies, it takes such appropriate cognizance of the limitations of the methods used as to restrict any answer obtained to the realm of engineering accuracy. In solving the problem for the average gas field, it was found that practically the same answers resulted as to pressure distribution, regardless of the size of the drainage radius, even though the latter was assumed to vary from a few feet as a minimum to that of the entire reservoir as a maximum. Such limits represent extreme possibilities; therefore, the practical conditions that are associated with normal development programs, in which wells are placed in the center of tracts varying in size from 40 to 640 acres, will of necessity result in less extreme variations than those indicated in the tables accompanying this paper. Stated more concisely, the amount of gas unrecovered at abandonment (of the particular field used for illustrative purposes) will lie somewhere between 4.6 and 6 per cent of the total original content, no matter how intensively the field is drilled.

Jan 1, 1938

By Gail Moulton

THE oilfields in Illinois are located principally along the LaSalle anti-cline in the southeastern part of the state. The oil produced comes most largely from beds of Pennsylvanian and Mississippian age, but there is an increasing important production from deeper horizons, as will be noted under new development. The oil is largely of paraffine base, and has an average specific gravity of about 35° Baume. The rank of Illinois as an oil producer has dropped from third since 1913, when its production was exceeded only by that of California and Oklahoma, to eighth in 1923. This has been the result of failure to find new pools of considerable size to offset the declining production of the old wells and of the greatly increased production of some of the other states. The noteworthy features of petroleum production in Illinois during 1924 are: the low rate of decline for the state as a whole; the smaller percentage of dry holes; and the larger average initial yield of the new wells.

Jan 3, 1925

By George B. Holderer

The relation between man-hours of labor and production may be correlated for any industry, and already it has been widely used in piecework studies. It is not in general use as yet for recording labor efficiency of an enterprise or an industry. An exception to this is the Cement Institute, which tabulates the man-hours used in each operation and thus gets the total man-hours per barrel of cement. The writer knows of one steel company that keeps a complete record of man-hours for every operation from mining the ore to finishing the product. No doubt many others find the information useful, and such a study could be of value to the mineral industries.

Jan 1, 1937

By L. A. Jr. Norman

ANOTHER chapter in the history of Mother Lode mining is being written by operations in the Old Eureka mine near Sutter Creek, Amador County, California. During a two-year period (1938-1939), 85,517 tons of ore averaging 0.62 oz. gold per ton were mined and milled, as compared to the production of approximately 210,000 tons of 0.315-oz. gold ore during the preceding seven years. This is a repetition of mining history in the Mother Lode, where a period of prosperity has followed a long period of lean production. The location of this new ore in the hitherto unproductive hanging-wall greenstones and its mining and geological developments are most interesting.

Jan 1, 1939

By C. A. Allen

FOR over three years we have been endeavoring to reduce the number of fatalities and minor accidents in Utah. The physical condition of the o? Represents the average of 4 States mentioned excluding the catastrophes indicated. FIG. 1.-NUMBER KILLED PER MILLION SHORT TONS OF COAL PRODUCED IN COLO¬RADO, NEW MEXICO, UTAH, WYOMING, AND BITUMINOUS MINES OF THE UNITED STATES, 1914 TO 1920. mines, concentrators, and smelters is good, yet the number of accidents,

Jan 5, 1922

By J. G. Richardson, F. M. Perkins

Results and procedures are pre-cented covering a laboratory investigation of the effect of rate of water advance on the displacement of oil from clean water-wet sands. The experiments included water floods at atmospheric pressure with and without gas present over a range of flow rates from reservoir rates to rates ten thousand-fold higher. Water floods were also conducted at various rates at elevated pressure with no gas present. Other tests were made at elevated pressures by forming a free gas saturation by evolution of gas from solution in the oil before water flooding. Recovery of oil was found to be independent of the rate of water advance with or without gas present and independent of the pressure level of the water flood. A dimensionally-scaled model of a reservoir composed of a thick uniform sand was used to study the effect of rate on the tendency of water to underrun the oil because of the greater density of the water. Another model was used to study the effect of rate on the tendency of water to channel down the more permeable sand in a stratified reservoir composed of sands of diffierent per-meability in intimate contact. The effect of the presence of gas on the flooding conformance was studied with both models. The results obtained using these simple models provide a basis for predicting behavior in more complicated systems. INTRODUCTION In spite of the great amount of research on the flow of fluids in porous rocks, there still exists some disagreement as to the influence of the rate of water advance on the displacement of oil by water flooding. Various investigators have found that increasing the rate of water injection would decrease, increase, or have no effect on recovery of oil. One reason for this disagreement has been a lack of understanding of the effects of the capillary forces which influence the results obtained in the laboratory at low rates with short columns. Other causes of the disagreement have undoubtedly been inconstancy and uncertainty of the wetting properties of the porous media studied, inaccurate saturation determinations, and in some instances conclusions based on insufficient data. Capillary forces are involved in the displacement of oil by water in two ways. On the microscopic scale, the capillary forces control the dis- tribution of oil and water in the pore spaces of the sand. The magnitude of these forces is governed by the preference of the sand to be wet by water, the pore sizes and geometrical shapes, and the interfacial tension between the water and oil. On the macroscopic scale, differences in saturation at the flooding "front" when water displaces oil result in capillary pressure gradients. These gradients cause water to flow preferentially ahead of the front. In short laboratory columns at low rates, the front can span the entire column length. Also, at the outflow boundary the preference of sand to be wetted by water results in retention of water and a high water saturation in the region of the outflow face. This effect is commonly called the boundary effect.' The capillary pressure gradients which complicate the interpretation of flooding performance of short laboratory columns at low rates of water advance become negligibly small under certain conditions. The conditions where capillary pressure gradients are negligible are in long, homogeneous reservoir sands,' at high rates of water advance in short laboratory columns,3 and at any rate in laboratory columns as the residual oil saturation is approached. Thus, laboratory water floods, conducted

Jan 1, 1958