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Since 1571, when the Institute was founded, many of the most important papers in the English language, on the various phases of mining and metallurgy, have appeared as Institute publications. As members of the Institute regularly receive the publications in which they are interested, this discussion is primarily for nonmembers who wish to know of them. The Institute has several means of issuing papers which have been submitted and accepted. The monthly journal, Mining and Metallurgy, is the magazine of the Institute. In it appear notices and reports of official business as well as many papers and contributions which do not appear otherwise. The annual subscription price of the magazine to nonmembers is $3 per year; Canadian and foreign postage $1 extra; single copies 50 cents; back issues $1 each. Many papers are published separately each year. They are issued in one or the other of two numbered series; namely, Technical Publications and Contributions, and of the latter there are four forms: Preprints, Mimeographs, Reprints, and Unpublished Manuscripts. A Technical Publication or Contribution (in any form) is issued by the Institute when it is listed in Mining and Metallurgy. Technical Publications are sent automatically to members who have asked in advance for papers on a given subject. All members are entitled to a copy of every paper in either series, except when a Contribution is an Unpublished Manuscript. Con¬tributions in the form of Unpublished Manuscripts are filed in the Engineering Societies Library and copies of some of these papers may be found in a few selected libraries throughout the country.

Jan 1, 1933

By J. C. Coughlin, M. C. Flemings, T. Z. Kattamis

Experiments on Al-4.5 pct Cu alloy shou the dendrite arnz spacing increases with time during isothermal holding in the liquid-solid region. This coarsening of the dendrite structure is then shown to occur at roughly the same rate during solidification as during isothermal holding. Final dendrite arm spacing in both types of experiments depends primarily on coarsening kinetics. It is concluded that driving force for the coarsening is reduction of liquid-solid sur/ace area. Calculations based on two simple models show qualitative apreement with experinzent. 1 HERE has been considerable interest in recent years in determining effects of solidification variables on dendrite arm spacing in cast alloys. The interest has resulted primarily from the clear evidence that 1) the degree of homogeneity which can be obtained in a cast alloy with commercially practical homogeni- zation treatments depends on dendrite arm spacing, and 2) mechanical properties of the heat-treated casting depend on the homogeneity obtained.'-' In wrought alloys, microsegregation from the original ingot is carried to some extent into the final wrought product, and affects mechanical properties in similar fashion Experimental evidence available indicates that dendrite arm spacing in cast aluminum alloys is influenced only by cooling rate (or "local solidification timev*) and alloy content.Fig. 1, for example,

Jan 1, 1968

By Julian Kennedy Edgar

THINKING that it may prove of interest to the Institute, I have prepared a short account of the blowing in and subsequent working of the "A" furnace of the Edgar Thomson Steel Works. This furnace was built for the purpose of making spiegel, but has been started and is now running on Bessemer iron. The shape and size of the furnace are shown in the accompanying drawing. It will be seen that the section is formed of lines making very small angles with each other. In fact, an arc of a circle can be drawn, from the top to the tuyeres, which will nowhere deviate more than two inches from the lines given. In building, also, great pains were taken to gradually round the angles, so that the most careful observer, standing in the crucible and looking upward, could not tell at what points the slopes changed. It will also be seen that the widest part of the furnace is almost exactly midway between the bottom and the stock line, The flattest slope is maintained for 20 feet above the crucible, and is about 1 s inch to the foot from the perpendicular. The furnace is lined with small brick throughout, and has six tuyeres four inches in diameter, which project seven inches inside of crucible. There are three Siemens-Cowper-Cochrane stoves, each 15 feet in diameter by 50 feet high. Blast is furnished by an upright engine with 32-inch steam cylinder, 84-inch air cylinder, and 48-inch stroke. The steam cylinder has balanced poppet valves, working horizontally. The steam valves are worked by a Porter link-movement in order to obtain a variable cut-off. The exhaust valves are worked by a separate eccentric. It is intended to attach a governor to the cut-off, but at present it is set by hand. The steam cylinder is

Jan 1, 1880

By Isobel Clark

The increasing complexity of modern mining technology makes it ever more difficult to decide on the 'best* way to solve problems in mine planning. Yet with escalating costs it becomes increasingly more important for the mining engineer to be able to evaluate quantitatively the implications of the 'what happens if' postulation on the efficiency and economics of exploitation. The use of a model of the orebody can yield an estimate, not just of overall expected results, but also of the sensitivity of these results to possible variations in the orebody. Estimation techniques, such as Kriging, will produce the expected value for the grade of ore at any given point, or over any given volume within a deposit. However, the actual grades mined during production will - of necessity - differ from the predicted values. These possible variations, and the sensitivity of the management decisions to them, can be investigated in detail by the use of simulation. An orebody can be simulated which follows the known characteristics of the deposit at any given stage in development. These properties might be the histogram of grade values, the semivariogram from the samples, the actual borehole assays, geological constraints and/or interpretation, topography, lease boundaries etc. This would be one possible 'realisation' of the deposit as dictated by the currently known data. If several of these simulations are carried out, each conditioned to the current knowledge of the orebody, then it is possible to gain an idea of the range of possible outcomes of any mining procedure or decision taken - all of which are equally likely. Not only can the best decision then be taken, but its sensitivity to the inherent variation within the orebody, and to the ever present estimation errors may be thoroughly studied.

Jan 1, 1977

Such are the rigors of climate and topography of western Tasmania, that much of the area has remained uninhabited. The mountains, rising to peaks above 5000 ft high, receive the winds out of the west and precipitate 110 in. of rainfall a year on this coast. The drenched forests have a primordial look with such unfamiliar trees as the tru-sassafras, blackwood, cheesewood, ti tree, and man tree ferns. Prospectors speak of the "horizontals," trees which, in the dense foliage, grow out flat. When the explorer climbs over them he does not come back to the ground but continues forward on dense vegetation with the ground many feet below. Gold was discovered by the intrepid prospectors of the late nineteenth century and stamp mills were erected in the vicinity of Zeehan and Queenstown. At Mount Lyell, mining began for gold in the ironstone capping. The familiar story, of course, is that copper was found beneath the gossan and it was this mineralization that lead to permanent mining operations. Two companies began mining at Mount Lyell and their history from 1893 to 1902 was marked by an unreasonable competitiveness, human perversity and technical difficulties. The North Lyell and Mount Lyell companies were mining copper ores within one mile of each other separated only by a ridge. Each company built its own railroad and harbor. For six years of struggle both companies tried to work out the metallurgical problem which was the key to profit. Although they didn't know it, the two ores were complimentary and could have been smelted together. North Lyell ore was strong in silica and weak in iron, whereas Mount Lyell was fortunate in having a first-class metallurgist in Robert Sticht, from Brooklyn, N. Y., who in 1902 successfully achieved pyritic smelting without the use of carbon fuel.

Jan 10, 1964

By A. W. Hahn

ALTHOUGH enormous tonnages of sulfide lead and lead-silver ores are treated by flotation, the products of flotation mills treating oxidized ores of lead and silver are almost negligible. However, each year there is a slight tonnage increase, and it is possible, should a sizeable oxidized lead ore tonnage be developed, the field will become an important one. In 1918, the Shattuck-Arizona Copper Co. erected a plant at Warren, Ariz., for the treatment of oxidized gold-silver-lead ores. Glenn L. Allen worked out the metallurgy for this plant, employing tabling, followed by flotation concentration. The Shattuck-Denn Mining Co., successors to the Shattuck-Arizona Co., now employs straight flotation in the same mill, treating about 200 tons daily. In 1922, the San Diego mill of the American Smelting & Refining Co., in the Parral district, Chihuahua, Mexico, started operating a 600-ton mill on a mixed sulfide-oxide gold-silver-lead ore. Tables and flotation are used here, and about 200 tons of oxidized slime treated by flotation. In 1923, the Eureka Holly Mining Co. started operating a 90-ton mill at Eureka, Nev., using tables and flotation, on an oxidized lead-silver ore. In 1924, the American Smelting & Refining Co. started a 250-ton mill in northern Peru, to treat a high grade oxidized gold-silver ore with very low lead values. In 1924, the Grand Central Mining Co. started a 200-ton flotation mill on old oxidized gold-silver-lead tailings at Fairbank, Ariz. In 1926, the Compania International Minera, a subsidiary of the Union Corporation of London, started a 250-ton flotation mill on oxidized lead-silver ores, and during April of this year, the Phelps-Dodge Corp. will probably start a 250-ton mill at Warren, Ariz., on oxidized lead-silver ores, similar to those being treated in the Shattuck-Denn mill.

Jan 1, 1927

By A. J. Weinig

The method described is a modification of Schutzenberger's whereby the solution in titrations and the standards are protected from the atmosphere by a layer of kerosene. Indigo-disulfonate is the indicator and sodium hydrosulfite the standard. The method is rapid and delicate. It has been tried on a variety of mill solutions and mill men have found the method of value. THE important part that dissolved oxygen plays in the cyanide treat-ment of gold and silver ores is commonly recognized by most metallurgists and mill men.. But heretofore there has been no simple method on which the mill man could rely for determining the amount of oxygen in the various mill solutions. A few methods are adaptable to the, laboratory, such as the gasometric1 determination by actually measuring the oxygen. Winkler's2 iodometric method, and Schutzenberger's3 method, which depends on the reducing action of sodium hyposulfite on a blue solution of indigo carmine; but these are not readily adaptable to the needs of the mill man and cannot be applied to cyanide solutions without modification. The gasometric method is the most accurate but it takes too long to complete a determination. White's' method (a colorimetric method that depends on the degree of coloration imparted to a solution of pyrogallic acid in the presence of caustic soda) although much more rapid than any of the methods named, often gives misleading results on account of grading of colors of different solutions, which nearly always contain various kinds of salts. The method herein described was devised for the use of the mill man, the aim being to develop a simple, practical, accurate method. It is a modification of the Schutzenberger method and depends on the reducing

Jan 8, 1924

By David C. Grant, Erich W. Tiepel

In situ mining is a process for recovering uranium from relatively small or low grade ore bodies. The process involves passing a lixiviant and oxidant, typically NH4HC03 and H202, through a uraniumcontaining ore body. As the solution progresses through the ore body, the uranium is oxidized from the plus four to the soluble plus six state. The bicarbonate complexed uranium laden solution is removed from the ore body and the uranium recovered in an above-ground processing plant. During the leach process lixiviant cations may be sorbed on the ore host, if the host contains exchangeable clay minerals. This report examines the implications of this clay interaction on ground-water quality, the various available in situ mining restoration methods, laboratory procedures for simulation and development of those methods, and the results of using the restoration methods in the field. Various restoration methods, including ground-water sweeping, clean water recycle, and chemical restoration are presented and discussed. The use of ore characterization, agitation leach tests, and column tests to study cation sorption and desorption, and thus, to identify and evaluate restoration methods is discussed. Ore characteristics identify the clay type and clay content, which allows the estimation of the magnitude of the cation sorption by that ore. The chemical effects of clay exchange and of chemical restoration can be examined using agitation leach experiments and packed ore column tests which also provide information on the physical effects. The agitation leach test is a relatively rapid means of determining the sorption and desorption characteristics of an ore. Unlike agitation leach tests, column tests can be used to assess the influence of solutions on permeability, on precipitation problems, and on other chemical changes. The effectiveness of using restoration methods, which were developed and tested in the laboratory, are examined by presenting field restoration data from several mining sites.

Jan 1, 1979

By C. P. Karr

FOR several years, the Bureau of Standards has been working in cooperation with an Advisory Committee on non-ferrous metals on various phases of the production and testing of zinc bronzes. The work has dealt, especially with the type of metal known as "Admiralty bronze" in England and as "Government bronze" in this country and consisting of 88 copper, 10 tin, and 2 zinc. Several reports have been made on this subject and these should be considered in connection with this paper.1 FIRST SERIES OF FIVE FOUNDRY TESTS A very brief summary of the first series of five foundry tests has been made,2 but for the sake of clearness the results are given here in different form. The five foundries cooperating in this investigation were: Ohio Brass Co., Mansfield, Ohio; Titanium Alloy Mfg. Co., Niagara Falls, N. Y.; Packard Motor Car Co., Syracuse, N. Y.; National Cash Register Co., Dayton, Ohio; Bureau of Standards, Washington, D. C. The object of the work was to determine whether uniform results could be obtained with this alloy in different foundries working under definite instructions. One of the participating foundries prepared, from virgin metal, a stock of ingots of the composition 88 copper, 10 tin, 2 zinc, and at the same time poured nine test bars from this melt of virgin metal. The results of the physical tests of these bars are shown in Table 1. Examination of this table shows that the highest and most nearly uniform results were obtained when the virgin metal was cast flat in chill molds and the lowest and most variable results were encountered when it was cast vertical in green-sand molds. In this, as in all other tables, the mean

Jan 9, 1919

By Robert L. Davidoff, Rodney D. Rosenkranz

In order to determine copper resource data and production costs for major market economy mines and deposits, the Bureau of Mines has performed detailed engineering and economic analyses on 271 of the world's most significant copper deposits. At the demonstrated resource level, copper potentially recoverable from these deposits is estimated to be 325 million metric tons, 180 million tons of which would be from Pacific Rim countries. Chile has the largest known copper resources of any country and accounts for nearly 45 percent of the copper avail- able from Pacific Rim countries. At $1.00 per pound, in January 1981 dollars, an estimated 80 million metric tons of copper are potentially economically recoverable from Pacific Rim deposits. At this same price, analyses indicate that these deposits could economically produce about 2 million metric tons of copper per year. Sensitivity analyses reveal that if operating costs were to decrease 25 percent, with copper at a price of $1.00 per pound, total copper economically recoverable from Pacific Rim countries could increase by about 10 percent; a 25 percent increase in operating costs could lower economically recoverable copper by 50 percent. Analyses also indicate that byproduct prices are important. If byproduct revenues increased 25 percent, at a copper price of $1.00 per pound, an additional 2 million metric tons of copper could be recovered; if byproduct revenues decrease 25 percent, about 5 million metric tons less of copper metal would be available. Since the January 1981 date of this study, inflation and decreases in copper and byproduct prices have greatly affected the profitability of the world copper industry. Many producing mines have curtailed or suspended production, and development of many non- producing deposits has been postponed.

Jan 1, 1982

By D. T. MacRoberts

A simple disturbance in a gas reservoir travels with a finite velocity which is nearly independent of the amplitude of the disturbance. As a result very complex transients may be set up which seriously affect observation at a well. The time of transient is much longer than commonly supposed. INTRODUCTION A change in pressure at a gas well is not propagated through the reservoir instantaneously but with a definite fin- ite velocity. Knowledge of the period ! of this transient is of value because: 1. Observations of pressure and flow-rate during the transient may affect interpretation of back-pressure tests. 2. Interference effects between wells may be used to determine continuity of formation. 3. Additional information concerning the physical characteris- tics may possibly be deduced from the behavior of a well during the transient. MATHEMATICAL DEVELOPMENT It will be assumed that the well is initially closed in and that the pressure is constant throlughout the reservoir. As the initial disturbance passes outward from the well it is further assumed that a logarithmic pressure distribution is established between the most distant point reached and the well, so that: <l> = ((/)r-<t>w) I ------------ + (/) . (1) Manuscript received at office of the Branch September 15. 1948. Paper presented at Branch Fall Meeting, Dallas. Texas. Oct. 4-6, 1948. r. = distance to any point between r and rw r = radius of drainge iw= radius of well (/) = potential (P for incompressible fluids, P2 for perfect gases) Up to the time the effect reaches the point r the production from the well will be: W= (Pr-P,,,) . (2) i b W = volume produced t = sand thickness F = fractional porosity Pr = reservoir pressure Pm = average pressure between r and rw Pb = atmospheric Pressure All pressures will subsequently be stated in atmospheres and the constant Pb will be omitted. This will be produced at a rate: dw t k (Pr³-PW2) do d 0 - . (3) log — Pw = pressure at the well k = permeability 0 = time = viscosity

Jan 1, 1949

A concept gaining attention among rock mechanics researchers in studies of soil-structure inter- action is the use of compressible packing between the structure such as tunnel lining and the soil or rock. Lester H. Gabriel, provided information about work on this concept at the II Symposium on Rapid Excavation, October 16-17, 1969, Sacramento State College, Sacramento, Calif. It is well-known that loads transmit their effects to those locations which deform least. Traditionally, the question to be answered by the structural engineer is how rigid the structure ought to be. The stronger the structure, the more resistant it becomes to deformation. If it is more rigid than the surrounding strata, the structure acts as a pillar, focusing load on itself. However, if the structure is less rigid than the surrounding strata, blocking or packing between the structure and the enclosing material facilitates the formation of soil or rock arch. The object then is to design and build structures such as tunnel linings, which harness the advantages of carefully planned small movements. Tests on plaster cylinders imbedded in granular sand and loaded were compared to those of plaster cylinders protected in sheathing of polyfoam rubber. The compressible sheath permitted support of up to ten times greater loads Gabriel, Lester H., "Principles of Soil-Structure Interaction Applied to Tunnel Linings." Hecla Mining Co. has successfully used shotcrete with substantial cost savings for ground support purpose. To date, the use of shotcrete in Hecla&apos;s operations has been limited to openings where long-term high quality support was required, in exceptionally difficult ground, and to a limited degree in stope support. Experience with both the wet and dry process indicated that the latter was better for their applications. The availability of effective accelerators which reduce losses from rebound, give high-early strength and permit placement in wet conditions, led to this conclusion. The gross cost under such conditions as those at Hecla, including rebound losses and overshooting, is estimated by Hecla to be $51 per cu yd.

Jan 12, 1969

By John F. Blandy

ALTHOUGH the question of the "waste of anthracite coal mining" has been so frequently discussed, and a committee was appointed at the first meeting of this Society to consider and report upon the subject, still but little progress seems to have been made in arriving at a conclusion as to how it can be reduced. That committee made a preliminary report at the August meeting, 1871, in which it divided the question into three parts, namely Waste in mining, in preparing for market, and in transportation. I shall not here refer to the first item, as so much depends upon the peculiar features of each separate mine, and the skill of those in charge; but in reference to the second, that of preparing the coal for market in breaker and screens, I wish to make some remarks. There is no use considering the question, whether the coal should be broken up to suit the fancy of consumers; all miners are satisfied that it should not be, but the consumers decide that they want it that way, and the miner must submit, and simply utter his maledictions upon the head of the man who first suggested a breaker or screen, if that is any consolation to him. What is called waste in this process of preparation, is the dust and fine coal, which results from the breaking and screening, and, as we all know, this is a very important percentage of what passes from the slope to the top of the breaker. Now, if this dust and fine coal can be utilized-the slate which is&apos; picked out is not to be taken into consideration as waste-then we get rid of this item entirely. There is no question in my mind that this article can and will be used as a steam generator at least, and I think, therefore, that in depositing

Jan 1, 1877

By Frank Firmstone

WE found it necessary, in December, 1874, to repair the upper part of the lining in No. 5 furnace at Glendon, and, as we succeeded in doing it with comparatively little trouble, a description of the plan followed may be of service to those having a similar operation to perform. On two opposite sides, as shown by the sketch, the lining was completely gone for a height of about four feet, below which it increased gradually in thickness, being nine inches thick about three feet lower down. On a plane at right angles to the section drawn, the brick were nowhere entirely gone, but were in some places not more than two or three inches thick, being still sufficient to sustain the upper part, where the brick, being above the level of the stock, were not at all worn. The furnace was blown down, so that when we cast and closed the tuyeres, about 7 A.M., on December 8th, the top of the stock was about twenty-four feet below the filling-plates. The walls were quite hot, and a good deal of gas was given off for several hours after the tuyeres were closed. The hopper and bell were thrown into the furnace, and were covered by filling several charges of cold stock over them, which at once greatly cooled off the top of the furnace. A wrought-iron pipe, thirty inches in diameter, in five sections, each six feet long, was then put down, and made to stand upright, as nearly as possible in the centre of the furnace. Around this we filled a double charge of coal, taking care to heap it up next the pipe, and let it get thinner as it got to the walls. This was covered with about two feet of fine ore, leaving the lowest joint in the pipe entirely uncovered. We were now ready to put in our scaffold to get at the

Jan 1, 1876

By D. T. MacRoberts

A simple disturbance in a gas reservoir travels with a finite velocity which is nearly independent of the amplitude of the disturbance. As a result very complex transients may be set up which seriously affect observation at a well. The time of transient is much longer than commonly supposed. INTRODUCTION A change in pressure at a gas well is not propagated through the reservoir instantaneously but with a definite fin- ite velocity. Knowledge of the period ! of this transient is of value because: 1. Observations of pressure and flow-rate during the transient may affect interpretation of back-pressure tests. 2. Interference effects between wells may be used to determine continuity of formation. 3. Additional information concerning the physical characteris- tics may possibly be deduced from the behavior of a well during the transient. MATHEMATICAL DEVELOPMENT It will be assumed that the well is initially closed in and that the pressure is constant throlughout the reservoir. As the initial disturbance passes outward from the well it is further assumed that a logarithmic pressure distribution is established between the most distant point reached and the well, so that: <l> = ((/)r-<t>w) I ------------ + (/) . (1) Manuscript received at office of the Branch September 15. 1948. Paper presented at Branch Fall Meeting, Dallas. Texas. Oct. 4-6, 1948. r. = distance to any point between r and rw r = radius of drainge iw= radius of well (/) = potential (P for incompressible fluids, P2 for perfect gases) Up to the time the effect reaches the point r the production from the well will be: W= (Pr-P,,,) . (2) i b W = volume produced t = sand thickness F = fractional porosity Pr = reservoir pressure Pm = average pressure between r and rw Pb = atmospheric Pressure All pressures will subsequently be stated in atmospheres and the constant Pb will be omitted. This will be produced at a rate: dw t k (Pr³-PW2) do d 0 - . (3) log — Pw = pressure at the well k = permeability 0 = time = viscosity

Jan 1, 1949

By Leo L. Van Sambeek

An understanding of the creep and yield behavior of salt is required for the rock mechanics design aspects of solution mining. Most previous studies of salt behavior have been performed on small specimens of salt under homogeneous stress conditions; i.e., uniaxial and triaxial tests on specimens <0.002 m3. The corejacking test is a larger scale test (-0.75 m3) with inhomogeneous stress conditions that provides data on the structural response of salt. Interpretation of the responses from eight such corejacking tests provides verification of the requisite constitutive parameters required to predict salt behavior at different levels of stress and temperature. These constitutive parameters are not those studied in the usual laboratory test. Corejacking test results show almost inseparable elastic and plastic closures simultaneous with the corejack pressurization. Very rapid closure (on a relative basis) continues for a period of time after the pressurization. This rapid closure is shown to be both continuing yield deformation and creep deformation. After the period of rapid closure, the closure rate approaches a constant value. Numerical modeling of the corejack tests using a creep law containing both transient and steady-state creep functions does not provide results that agree with the responses measured in the corejack tests. Using an experimental design technique plus additional numerical modeling that includes yielding of the salt, results in identification of the significant parameters which allow agreement. The significance of the results from the study is demonstrated by comparing the postulated stability and creep response of a solution-mined cavern using the previous understanding of salt behavior and the understanding developed from this study.

Jan 1, 1985

FRIENDS of the late Charles F. Rand presented in 1930 a sum of money from which the income is available to support various phases of the work of the Institute in which Mr. Rand was so deeply interested. At present the fund amounts to $10,900. The specific terms of the deed of gift are as follows: "The fund collected to establish a memorial to the late Charles F. Rand shall be placed in the custody of the Board of Directors of the American Institute of Mining and Metallurgical Engineers, to be set up as a trust to be known as the `Charles F. Rand Foundation,&apos; the income of which shall each year be applied to a distinct purpose to be decided upon in that year by vote of the Board of Directors. This purpose shall be such as to promote the general welfare of the Institute and to constitute a permanent memorial of the usefulness of Mr. Rand, who for many years gave unstintingly of his time and talents in its service. "It shall be within the discretion of the Board of Directors to establish a medal to be known as the Charles F. Rand Memorial Medal to be awarded at such a time and under such rules as may be determined by the Board of Directors, for Distinguished Achievement in Mining Administration." The establishment of this medal was announced at the annual meeting in February, 1932, the term "mining" being defined in its broad sense to include metallurgy and petroleum. Robert Linton is chairman of the Charles F. Rand Foundation Award Committee.

Jan 1, 1942

By Allen J. Johnson

It is probable that the word "anthracite" was derived from the Greek preposition an, and the Greek word for Thrace, meaning, in combination, "toward or near Thrace." Aristotle, Theophrastus, Strabo and Pliny all mention Thrace, or Samothrace, in treatises upon stones and stone coals dating back to about 371 B.C. In 1769 Obadiah Gore, a blacksmith of Wilkes-Barre, successfully burned anthracite in his forge, the first of millions of consumers of Pennsylvania anthracite. The Anthracite Region While anthracite is found in widely scattered locations throughout the world, 99 per cent of the total production of the United States origintitles within an area of 3300 square miles in castern Pennsylvania, less than 500 square miles of which arc underlain by workable coal beds. Eminent authorities such as the United States Geological Survey agree that this Pennsylvania anthracite is the only true anthracite east of the Rocky Mountains. There is some graphitic anthracite in Rhode Island but it is not suitable for combustion; and coals from such states as Virginia and Arkansas, frequently sold as anthracite, are in reality semi-

Jan 1, 1934

By C. E. Reinhard

A USEFUL accelerated weathering test should be capable of placing any series of metals quantitatively in the same order of endurance as that noted under a particular set of actual exposure conditions. The development of such a test must necessarily depend to a considerable extent upon data obtained from a wide variety of exposures. This paper offers preliminary data from exposure tests on nine metals placed in 11 locations in the Lehigh Valley, within a radius of 20 miles from Palmerton. The exposure conditions vary from a severe industrial atmosphere to a pure rural atmosphere. The data are offered as evidence of the necessity for the identification and evaluation of the variables of corrosion and as illustration of some of the variations to be considered in the development of a useful accelerated test. It is quite clear, from this evidence, that a useful accelerated test must be versatile to the extent of showing the probable variations of corrosion resulting from differences in atmosphere as well as from differences in the metals. The paper is presented solely with the object of pointing out the wide variations in relative merits of several common metals in resisting corrosion and without any thought of initiating controversy regarding the, merits of particular metals. For this reason the metals are designated only by symbols in the tables and no key is given to these symbols.

Jan 1, 1929

By G. Thodos, E. M. Phillips

A reduced density correlation for the gaseous and liquid regions of ethane has been developed from all the experimental PVT data available in the literature for this substance. Saturated vapor and liquid densities reported for methane, propane and n-butane were utilized to establish the rectilinear-diameter line for ethane. This line was then used with the saturated-vapor data for ethane to produce the saturated envelope for this substance. Most of the saturated liquid data reported for ethane were found to be inconsistent with the saturated-liquid curve resulting from this study. The correlation covers the regions 0.65 < TR <6.0 and 0 < PR < 15. For regions for which no experimental data have been reported, the isobars of the correlation were extended by the use of the theorem of corresponding states. This correlation is presented both on rectilinear and log-log coordinates. INTRODUCTION At the present time, there is considerable interest in the exact PVT behavior of pure hydrocarbons. Matschke and Thodos12 recently have developed a comprehensive compilation of experimental vapor and liquid density data for methane. Similar studies have been conducted for other pure substances.4, 7 In the present study the density data available in the literature for gaseous and liquid ethane have been critically reviewed and utilized to develop a reduced density correlation for this substance. SATURATED LIQUID AND VAPOR DENSITIES The rectilinear-diameter rule proposed by Cailletet and Mathias5 states that the sum of the saturated liquid and vapor densities of a pure substance is a linear function of temperature which passes through the critical point. This law, although empirical, has been well established by continued verification since its conception in 1886. This rule has been applied to the saturated density data of methane,6 propane 17 and n-butane8 to produce the straight lines presented in Fig. 1 which pass through the critical point TR = 1.00, Pr = 2.00. The rectilinear-diameter relationship for ethane was established from the lines for the other substances in Fig. 1 by plotting the quantity p~, + PR against zc for different reduced temperatures. A critical analysis of the saturated vapor and liquid densities reported for ethane by Kuenen,10 Maass and McIntosh,11 and Sage, Webster and Lacey18 revealed that the values of PR1 + pr resulting from these studies were inconsistent with the rectilinear-diameter line obtained from the reliable density data of the other substances, as shown in Fig. 1. In the analysis of these data, reduced quantities were calculated using the critical con-