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The meeting of the Board of Directors, on November 22, was attended by eight directors, the Secretary of the Institute, and eight guests. The proposed James Douglas Prize and Tablet was referred to a committee of eleven. Robert H. Richards was appointed representative of this Institute to attend the meeting of the Society for the Promotion of Engineering Education. J. V. N. Dorr was made chairman of the Finance Committee in place of George D. Barron, resigned. The sum of $200 was appropriated for the 1918 expense of the American Engineering Standards Committee; the question of an appropriation for 1919 was referred to the Executive Committee for study and report. The sum of $50 was appropriated to the Treasurer's clerk. The following representatives of the Institute were elected: W. L. Saunders to succeed himself as United Engineering Society Trustee; R. M. Raymond to succeed himself as member of Engineering Foundation Board; S. J. Jennings to succeed himself as member of Engineering Council; George F. Kunz to succeed himself as member of Engineering Council; C. F. Rand to succeed himself as member of John Fritz Medal Board of Award; E. Gybbon Spilsbury to succeed himself as member of the Library Board. To members of the Canadian Mining Institute residing in Canada or Newfoundland, the privilege was extended to subscribe to the Bulletin at the price of $5. An invitation was extended to the Mining and Metallurgical Society of America to consolidate with the American Institute of Mining Engineers. The appointment of Engineering Societies' Employment Bureau was reported. Thirty-nine members and ten associates were elected. Two members were reinstated. Extension of time for the payment of clues was granted to four members. Seventeen members on active duty at the front had their dues remitted.

Jan 1, 1919

By Herbert Everest

THE idea of economical production is usually associated with large operations, tonnages, and mines, with even larger capital behind them. Nevertheless many small mines operate in the shadow of large competitors and make a good showing on the capital invested despite larger overhead expenses. For the purpose of this discussion I will divide the cost of production into classes, and specify opposite each the approximate percentage expended thereon: 1. Labor, including miners and company men; 60 to 75 per cent. 2: Development, including all necessary yardage, room turning, crosscuts, etc.; 7 to 12 per cent. 3. Deadwork, covering payment to miners for handling falls, drawslate, or faults, rock work, water, and in general, all nonproductive labor; 3 to 7 per cent. 4. Supplies: mine timbers, oil, brattice material, lumber, cement, and repairs to equipment; 2 to 6 per cent. 5. Expense: management, selling, office, taxes, etc.; 1 to 5 per cent. 6. Depreciation of coal reserves and royalties; 6 to 10 per cent. 7. Depreciation of equipment and interest on capital invested; 1 to 3 per cent. 8. Fuel; ½ to 1 ½ per cent. The labor cost for a small mine is relatively much lower than for a large mine, particularly the sum paid to company men. Idle-pay expense is cut to a minimum; the labor item being larger than all the others together, a saving in labor makes a decided showing on the total cost. The development charges in small and large mines are about the same. There should be a small showing on the Beadwork item in favor of the small mine. The unit cost for supplies is usually small in the small mine. The operator of the small mine finds, owing to a limited tonnage, that the expenses of management, selling, etc., are abnormally high.

Jan 1, 1916

E. R. JETTE*—The way this ternary was developed there are two directly determined points on each of the iso-thermals except the 700° isothermal, where I believe there is only one. How were the end points determined, and what was the basis for it? Whose work formed the basis for the silver copper line ? M. B. BEVER †—At most temperatures the authors determined three points of the isothermal line. For example it can be seen from Fig 3 and 4 how three points for the 600°C contour line were obtained. The authors took two additional points for each temperature from the copper-silver binary diagram contained in Hansen's volume on constitution diagrams. It is correct that the 700°C contour line is based only on one point in the ternary field which was found by a slight extrapolation of Fig 4. R. I. JAFFEE*—Are the tie lines representing phases in equilibrium parallel to the silver-copper boundary ? M. B. BEVER—Are you asking that as a matter of principle ? R. I. JAFFEE—I assumed that would follow from principle. I wonder if that is in accordance with the authors' ideas too. M. B. BEVER—I do not believe the authors obtained any information on the tie lines in the two-phase field. Of course, in the limiting case of very low gold contents the tie-lines approach to the silver-copper boundary, but generally in the two-phase field I do not think that the tie-lines have to be parallel to the boundary. E. R. JETTE—1 am quite sure they do not have to be parallel. You cannot tell from this work in which direction they go. E. A. GULBRANSEN*—Were any pycnometric measurements made to check the lattice parameters of the alloys ? M. B. BEVER—I did not hear any-

Jan 1, 1950

By A. B. Parsons

This YEAR BOOK, which is sent to every member, contains the roster of officers and the principal standing committees, brief summaries of the proceedings of the Annual Meeting and of the Regional and Divisional meetings, and the necrology for the year 1934. Also are included abstracts of papers published during the year and a classified list of TECHNICAL PUBLICATIONS and CONTRIBUTIONS, as well as an index of all material published by the Institute in 1934 in TRANSACTIONS, in TECHNICAL PUBLICATIONS and CONTRIBGTIONS and in MINING AND METALLURGY, the monthly magazine, the twelve issues' of which contained 98 technical papers Thus 111 small space are gathered together references to all papers, magazines and books printed by the Institute during the year. The papers for the Iron and Steel and Institute of Metals Divisions have been issued as TECHNICAL PUBLICATIONS distributed under the binding of METALS TECHNOLOGY in the months of January, February, April, June, August, September, October, December This plan of distribution will be continued in 1935 for these two groups The publications for the year 1934 include two sponsored by the Institute's special funds. A Manual for Student Associates and Affiliated Student Societies, prepared by the Committee on Student Relations, of which Jay A. Carpenter was Chairman, was published through the courtesy of the Seeley W. Mudd Memorial Fund, and Volume 112 of the TRANSACTIONS, on Milling Methods, assembled by the Committee on Milling Methods, of which Charles E. Locke was Chairman, was financed by the Rocky Mountain Fund The remaining volumes were all TRANSACTIONS, Volumes 107, Petroleum Development and Technology; 108, Coal Division; 109, Metal Mining and Nonmetallic Minerals; 110, Geophysical Prospecting; 111, Institute of Metals Division and 113, Iron and Steel Division

Jan 1, 1935

The Institute makes liberal provision for inclusion of engineering students through individual Student Associate membership. Such members pay $2 per year, receive MINING AND METALLURGY, may purchase Technical Publications at reduced rates, have the privilege of attending all meetings and are furnished a distinctive badge in the form of a watch fob. Provision is also made for the affiliation of organized student societies in recognized schools of engineering chemistry, geology and related sciences. In order to qualify for affiliation it is not necessary that all members of the society become Student Associates since the individual members of the society are not listed as members of the Institute However, a large majority of the members of many of the societies are also Student Associate Members of the Institute. Among the things that the Institute does for the affiliated societies are the following: (a) A copy of each issue of MINING AND METALLURGY is furnished to the society; (b) Reports of the meetings and activities of the society are reported in MINING AND METALLURGY; (c) Assistance is given by the Institute in obtaining speakers for the meetings of the society; (d) The name of the society and of its officers is listed in the annual Directory and other publications of the Institute; and (e) Members of the society are given the use of the Engineering Societies Employment Service. Student organizations, desiring to be recognized as affiliated student societies of the Institute, should make application to the Secretary, giving particulars as to the nature of their organization, of their membership, and their officers. The accom¬panying list on page 24 gives the names of the affiliated student societies, their presi¬dents and their secretaries, as of April 17, 1931.

Jan 1, 1923

The Institute makes liberal provision for inclusion of engineering students through individual Student Associate membership. Such members pay $2 per year, receive MINING AND METALLURGY, may purchase Technical Publications at reduced rates, have the privilege of attending all meetings and are furnished a distinctive badge in the form of a watch fob. Provision is also made for the affiliation of organized student societies in recognized schools of engineering, chemistry, geology and related sciences. In order to qualify for affiliation it is not necessary that all members of the society become Student Associates since the individual members of the society are not listed as members of the Institute. However, a large majority of the members of many of the societies are also Student Associate Members of the Institute. Among the things that the Institute does for the affiliated societies are the following: (a) A copy of each issue of MINING AND METALLURGY is furnished to the society; (b) Reports of the meetings and activities of the society are reported in MINING AND METALLURGY; (c) Assistance is given by the Institute in obtaining speakers for the meetings of the society; (d) The name of the society and of its officers is listed in the annual Directory and other publications of the Institute; and (e) Members of the society are given the use of the Engineering Societies Employment Service. Student organizations, desiring to be recognized as affiliated student societies of the Institute, should make application to the Secretary, giving particulars as to the nature of their organization, of their membership, and their officers. The accompanying list on page 21 gives the names of the affiliated student societies, their presidents and their secretaries, as of April 16, 1933.

Jan 1, 1932

THE second award of the Saunders Gold Medal for "distinguished achievement in mining," of which the first was awarded last year to the late D. W. Brunton, has been made to Herbert Hoover. The main events of Mr. Hoover's life are so familiar to all through the numerous journal articles about him and his work, and the interesting biography written by Vernon Kellogg, that no attempt will be made here to touch on anything other than his achievements as a professional mining engineer, for which the award was made. He graduated in mining from Leland Stanford, Jr., University in 1895, but had served as an assistant to Dr. Branner on the Arkansas Geological Survey in 1893 and had also worked two sum-mers as an assistant to H. W. Turner and Waldemar Lind-gren on U. S. Geological Sur-vey work in the Sierra Nevada around Lake Tahoe, and on the American River. Immediately after graduation he got "a job" underground at Grass Valley, and soon rose to be night shift-boss. He then secured employment with the late Louis Janin and made such a good record as office and field assistant that he was soon placed in charge of a small mine at Carlisle, N. M. In 1897, Mr. Janin recom-mended him to Bewick, More-ing & Co., who were looking for an examining engineer for their staff in Australia. Two years were spent in hard work there which was done so creditably that his princi-pals held him and his judg-ment in the highest regard, and he came to the head of their local organization. Among the properties which he acquired for them was the Sons of Gwalia.

Jan 2, 1928

By R. C. Beckstrom

Russia's first "Petaletka'' has ended. Technically it did not succeed but practically it has been a great achievement in the petroleum industry. Out of the chaos of revolution and civil war Russia has developed her oil industry to second place in the world's production. For 1932 production of crude oil is estimated at 150,000,000 bbl. and refined products at 145,000,000 barrels. Russia has been able to give the petroleum industry every advantage that a government can extend to a fast growing industry. She has obtained all of her property by confiscation. Under government ownership, operation and control, her petroleum industry is not handicapped in any way by state rulings or by unnecessary competition in production, refining and marketing. There are no damage suits resulting from offsetting, flooding, repressuring, laying of pipe lines, building of docks or other necessary work. Russian oil fields2 have been easy to develop and operate. They lie advantageously to transportation for foreign markets. The chief disadvantages have been a lack of credit and technical cooperation, but the former is being overcome by the sacrifice of the people. They go without the comforts of life that all salable articles may be exported for the imports of modern machinery. Modern machinery is fast replacing the obsolete and worn-out equipment. Technical cooperation has been difficult because it has been necessary to train thousands of adults to do technical and mechanical work. Great quantities of pipe, tools and electrical equipment were necessary for the rapidly developing fields and refineries. The supplies have been inadequate and the quality poor. This lack of equipment, along with the untrained technical supervision, has been the cause of the proposed quota falling short. Fig. 1 shows the production for 1931 and 1932. During 1932 a large percentage of the oil was produced in the proven fields of the Caucasus.

Jan 1, 1933

By Walter G. Perkins

In the assay of copper-bearing material for gold and silver, the elimination of copper before the final cupellation is of course essential, because any copper left in the lead-button will carry gold into the cupel; and a method which will effectively remove the copper with the smallest amount of manipullation is desirable. The scorification method is often rendered long and tedious by the necessity of repeatedly re-scorifying the button— to say nothing of the risk of losing Au—Ag thereby incurred. An ore carrying, for instance, 10 per cent,. of copper and only 0.1 or 0.2 oz. gold per ton, cannot be scorified with accurate results, because so many portions would have to be taken in order to get enough gold for weighing. On the other hand, the crucible method, with potassic nitrate and nails, would not do at all in such a case, because all the copper would be reduced by the nails, and (if the charge were 0.5 A. T.) this would defeat cupellation, by causing cupel-absorption of gold. In matte-assays, more concentrated value permits the determination of gold from smaller portions, and thus diminishes the difficulty experienced with ores. The method here described has been severely tested, during use for more than a year, and hart never failed hitherto, in the assay of any ore or product to which it has been applied. It is not proposed as perfect for every variety of ore or matte—probably no method would be that; but it is believed that, intelligently used, with the modifications dictated by practice, it will give better results, with less expenditure of time and labor, than any other known to the writer.

Jan 1, 1902

At the meeting of the Board of Directors the following resolution was passed: "The members of the Board of Directors of the American Institute of Mining Engineers desire: to place on record their appreciation of the very great generosity of one of their colleagues and a member of the Board, George D. Barron, expressed in his gift of $5000 to relieve the financial stringency caused by the unusual expenditures of the Institute for war work and the remission of dues of those members on active service." By-Law VIII. was amended to make a slight change in District No. 5. The report of the Auditing Committee was accepted. Tellers were appointed to: count the ballots on officers and on the proposed amendment. The proposed budget for the year 1919 was presented. The following resolution re Secretary Emeritus Rossiter W. Raymond, which had been prepared, by request, by Dr. A. R. Ledoux was then unanimously adopted. "The Board of Directors of the American Institute of Mining Engineers would place upon its minutes its profound sense of loss and sorrow in the death of Rossiter Worthington Raymond, Ph. D., LL. D., Secretary Emeritus of the Institute. Both as one of its founders and as its Sec-retary for 27 years, his was the guiding spirit of the Institute for more than a generation. "During the greater part of this long period, it might almost have been said that the Institute was Dr. Raymond-and Dr. Raymond the Institute. When with the progress of growth and development, great changes were introduced, Dr. Raymond acquiesced in these in spite of some misgivings, such as those with which a father might contemplate the emergence of his child from the careful supervision of the home; but as Secretary Emeritus for the past eight years, lie was always ready with valuable advice and helpful suggestion.

Jan 3, 1919

By M. T. Abasov

The work suggests an approach to the problem of optimally planning the drilling and development of gas fields. The approach is based on systems analysis and allows a joint optimal choice of the total number of wells in the field, their spacing in the reservoir, the diameter of production tubing, drilling dynamics, the number and spacing of drilling platforms and well pattern schemes for each plat- form as well. The optimal solution satisfies the set of technical- economical requirements and provides a minimum value of discounted total expenditures (capital costs plus operating costs). A mathematical model of the problem is presented. This work represents an extension of the authors&apos; previous investigations that formulated and solved problems of optimal drilling of oil and gas deposits by directional wells [1] and problems of optimal control of the number of active wells in multi-reservoir oil and gas fields [2], [3]. For construction of the mathematical model we choose a range (Nmin, Nmax) of possible values of the total number of wells, N, which should be drilled in the deposit. Here Nmin, Nmax are minimum and maximum numbers of wells correspondingly, that should be drilled into the reservoir. N[€](Nmin = N1, ... N[o], ..., Nm = Nmax). For simplicity a one-reservoir gas field is considered. It is assumed that: (a) wells are spaced in the reservoir uniformly, (b) there is a certain algorithm providing a uniform spacing of the given number N[o] ([0]=l, . . . , m) of wells in the reservoir, (c) the diameters of the production tubing for all the wells are the same. The relation Qz (x), i.e. the dependence of the cumulative output of gas from the cumulative "well-years" of operations is constructed for each diameter dZ from the given range of diameters d1< ...< dr.

Jan 1, 1977

By J. D. Audley Smith

Heine&apos;s " blue test" for copper, as described by the authorities generally, calls for a set of standard colors; and there has been some discussion concerning the relative superiority, for this purpose, of sulphate and nitrate solutions. The whole matter evidently hinges on the preservation of the standard colors in well-stoppered bottles. The apparatus described by Q. L. Heath* cannot be much improved, when very accurate readings are required. The following method was devised for the purpose of doing away with preserved sets of standard colors, by making a fresh standard for each batch of assays. The solutions are prepared in the usual way, each ammoniacal solution being filtered into its separate bottle, and then filled up to the containing-mark and thoroughly mixed. A similar color-bottle, with an " S " etched upon it, to distinguish it from the other bottles, which are numbered to correspond with the samples, is kept to run the standard. About 150 C.C. of water is put into it, and then the amount of acid (sulphuric or nitric) present in each determination, followed by 30 C.C. of ammonia (s. g. 0.90), which should make the mixture strongly ammoniacal. The liquid is now made up almost to the containing-mark (200 c.c.), say within 1 C.C. The lowest assay is selected first and placed alongside the standard, which, at the beginning, contains no copper. A copper-solution is then dropped into the standard from a burette ; and after each addition the bottle is well shaken and compared with the assay-sample. This operation is repeated until the two shades match exactly, when the burette is read and the assay-result is calculated. The assay next in order of depth of color is now taken and treated in the same way, and so on, until the batch is completed. It

Jan 1, 1901

By R. W. Jenkins

RACKLESS equipment is being used by the T Coplay Cement Manufacturing Co. to develop a folded limestone deposit economically and safely with inexperienced men. Cost and quality of development stone results in a saving when it is used instead of outside sources of limestone. This favorable cost has been attained by following a methods development and training program described in this paper. It is expected that further savings in favor of the mined stone will be made when stopes now being prepared are in production. The present equipment will be used for loading from stope draw points. The limestone is blended with quarried cement rock to serve as raw material for Portland cement, first produced in this country by Coplay Cement Manufacturing Co. from a process developed by its president, David 0. Saylor, in 1873. For many years the cement rock alone or with a small amount of added limestone was used for raw materials. Later as specifications were raised and the richer portions of quarries were depleted, limestone from outside sources was required in increasing amounts. In 1925 D. J. Uhle, the general manager, began to prospect company property for limestone. It was known that the argillaceous cement rock was underlain by crystalline high calcium limestone. After an extensive drilling program it was found that there were large reserves of limestone underlying a recumbent syncline exposed in the south wall of the company&apos;s No. 3 cement rock quarry. A quarry was started on the vertical limb of this fold in 1927, and by 1930 the full requirement of the plant was met. After 1945 production diminished because of the occurrence of dolomite beds in the south wall. The quarry floor was then 135 ft below the cement rock level and 285 ft below surface. In 1949 Gerald I?.

Jan 1, 1955

By Richard P. Rothwell

Though coal has been mined in this country for more than a century, no systematic effort was ever successfully made to ascertain the total amount produced. The production of the Cumberland Basin, Md., and the shipments from the anthracite fields of Pennsylvania, have been placed upon record, thanks to the intelligence and foresight of Mr. C. Slack in the former case, and to the late Mr. B. Bannan in the latter. For some of the years between 1822 and 1842, the production of the Richmond Basin was reported by Mr. R. C. Taylor, but since that date till the author undertook this work it was impossible to obtain any statement of the production of this field. A few of the newer fields, such as that of Mt. Diablo, Cal., have been fully reported, and a few of the newer States have also had this service performed by some intelligent private individuals; but no statistics of coal production have ever been collected either by the State or General Government, if we except the returns for the years 1869—70 of the census report. During the year 1875, by great exertions, I succeeded in obtaining, and July 3d, 1875, gave in the Engineering and Mining Journal what, " though not an accurate statement of our coal production," was " by far the most full and reliable that had ever been published." Though that report showed the production of bituminous coal to be 23,630,094 gross tons, or about six million tons more than had ever before been reported, it was in reality two and a half million tons below the actual output. The more full returns I obtained for 1875 gave many figures for 1874

By J. O. McCaldin, P. Duwez

ALLOTROPIC transformations between 1000° and 1900°C have recently been reported for several metallic elements. Since the proposed transformations are based on limited evidence, it was decided to examine the elements in question as well as some refractory metals by thermal analysis with a photoelectric technique similar to that described by Hug-gins, Roll, and Udin.1 In this method, a lead sulphide cell was used to detect thermal radiation from an electric-resistance heated strip specimen. A thermocouple spot welded to the specimen was used to calibrate the temperature of the system under steady temperature conditions, and recording was accomplished with a cathode ray oscilloscope. In the method used by the present authors, the temperature calibration was omitted and the cathode ray oscilloscope was replaced by a recording galvanometer. This technique, in which electric current passing through the specimen heats it, will be referred to henceforth as Method 1. Another arrangement was required for those cases where the specimen could not be formed into a wire or strip suitable for resistance heating. In such cases the specimen was a sintered compact heated by thermal radiation from a hot tungsten strip, Fig. 1. The specimen was insulated from the heating strip with a thin layer of thoria powder or suspended on 0.004 in. tungsten wires. The take-up spring had just sufficient tension to prevent buckling of the heating strip due to thermal expansion. This technique will be called Method 2. Both methods were tested with specimens of iron and titanium and the well known allotropic transformations, a toy and ? to 8 in iron and a to in titanium, were very clearly detected. Fig. 2 shows one of the records obtained for titanium. For this particular experiment, the iodide titanium specimen was a square rod 0.080 in. on an edge and 3 in. long.

Jan 1, 1955

By Francis S. Kendorski

INTRODUCTION Nuclear waste has been generated since the time of the Curie&apos;s and continues to be generated worldwide at an ever-increasing rate as the world will (and should) rely more and more upon fission (and hopefully fusion) for power. Also, the needs for strategic weapons will also generate so-called defense wastes. The largest class of high level nuclear waste (HLW) is spent fuel, the tail end of the nuclear reactor fuel cycle. At present, spent fuel is stored at the reactors producing it or at a few accepting places for away-from-reactor storage. All such storage facilities, as presently constructed, will begin to run out of usable storage space during the next decade or so. Congress enacted and President Reagan signed into law in early 1983 the National Nuclear Waste Policy Act of 1982. This law provides for the permanent isolation of nuclear waste in deep geologic repositories. The Act sets 1998 as the date at which the first repository should be operational. This date is extremely ambitious, and the Department of Energy (DOE), which is charged with the responsibility of constructing and operating repositories, admits that this date will slip by at least a few years. The Act also provides for licensing of repositories by the Nuclear Regulatory Commission (NRC) in a fashion very similar to nuclear power generating reactors. This requirement imposes a very special rigor on the analyses, investigations, designs, construction, and operation of repositories so as to assure the protection of the public and the environment from radioactive contamination. In addition the states and affected Indian Tribes must be consulted, especially concerning siting, and, needless to say, no one wants a HLW repository in their back yard.

Jan 1, 1984

By Tom W. Pfeifle, Paul E. Senseny

INTRODUCTION Engineered structures such as mines, shafts and tunnels, and storage caverns for hydrocarbons, chemical s and brine are being built in natural rock salt formations in increasing numbers. In addition, salt formations are being considered as potential hosts for mined, nuclear waste repositories. The popularity of these formations for engineering purposes stems from the many favorable commercial, physical, and thermal characteristics attributed to the material itself. Not only have the formations been stable and free of dissolution for hundreds of millions of years, but the salt is fairly easily mined and has very low permeability, low water content, and high thermal conductivity. Another characteristic of salt is its tendency to flow or creep when subjected to a shear stress. Although this behavior may be desirable in certain instances, it may be detrimental in other instances since the creep rate may be large enough to produce deformations that tend to reduce the volume of storage caverns or to restrict access to mining operations. In either case, the engineer is faced with the problem of accurately predicting the long-term structural deformations under various combinations of stress and temperature and is required to compare these deformations with long-term design criteria. In the laboratory, deformation-versus-time curves obtained at constant stress and temperature show that creep of salt is similar to creep of many other crystal line solids. Figure 1 shows a typical deformation-versus-time curve for salt. When a shear stress is first applied, the rate of deformation is high, but decreases monotonically. This initial behavior is called transient or primary creep. At some time, the deformation rate no longer decreases but continues at a constant rate. This behavior is called steady-state

Jan 1, 1982

By Utley Wedge

In general, the art of securing copper from sulphide ores or concentrates may be said to consist of: (1) separation, in the molten state, of copper sulphide with some iron sulphide, from the great bulk of gangue-material, followed by (2) elimination of sulphur and iron from the molten matte, by oxidation and fluxing, leaving metallic copper. The definition is made broad enough to cover the general practice, whether or not the ore or concentrate is given a prelimiuary roast for the removal of surplus sulphur. The above process, which I will designate as the smelting process, makes necessary the presence in the ore, or the addition thereto, of such silica, lime, and iron as may be necessary for the formation of a light and fusible slag, together with sufficient sulphur and iron for the formation of copper-matte, and also the addition to the matte of sufficient silica for the oxidation and fluxing-out of the iron. These items, together with the cost of fuel sufficient for melting the mass, constitute important items of cost in the copper-smelting process. Numerous cases where fluxing-materials are scarce or dear, or where fuel is expensive, have caused special attention to be given recently to the wet process of copper-extraction, which may be designated as consisting of forming soluble copper salts which are then washed or leached out of the ore or concentrates by dissolving in water or acid. Metallic copper may then be secured from the solution of copper salts by electrolysis; by cementation; or copper can be brought out of the solution as a hydroxide or other insoluble precipitate and reduced to metallic copper by subsequent melting in a reducing atmosphere.

Jan 1, 1913

By Joseph Taylor

THE Ducktown district is in the extreme southeastern corner of Tennessee, its principal railroad point being Copperhill, on the Blue Ridge division of the Louisville &Nashville Railroad, midway between Knoxville, Tenn., and Atlanta, Ga. The ore deposits were discovered about 1849 and development work was begun in the early fifties. Only the "black copper? ores, products of secondary enrichment, from beneath the gossan outcrops and overlying the massive sulphide deposits, were then mined and smelted for their copper content. Upon their exhaustion, attention was directed to the treatment of the pyritic ore remaining, resulting in the devising of a, process consisting of open-heap roasting, followed by blast-furnace smelting, which was practised until 1903, when semi-pyritic smelting was-adopted. In 1908, the companies operating in the district; on account of litigation brought about by alleged smoke damage to forests and vegetation in the adjoining counties of Georgia, were compelled to erect enormous acid plants to prevent the escape of the sulphur dioxide produced in the smelting operations. The utilization of this sulphur dioxide in the, manufacture of sulphuric acid as a byproduct has added to the revenues of the companies, and at the same time has furnished a valuable source of supply of sulphuric acid to the fertilizer trade of the South, and more recently to the manufacturers of explosives for use in the production of war munitions. The steadily increasing demand for sulphuric acid for the manufacture of fertilizers and explosives, together with the decreasing imports of pyrites, from which the acid is generally produced, now makes it imperative that greatly extended resources of pyrite be developed. While the Ducktown deposits do not predominate in pyrite, they do contain an inexhaustible supply of pyrrhotite, admixed with pyrite, which can be satisfactorily employed to supplement or substitute for pyrite in acid making.

Jan 2, 1918

By J. P. Neumann, Y. A. Chang

Lattice parameter measurements of the hcp phase in the system Ag-A1 near the stoichiometric composition Ag2Al were carried out for specimens quenched from 825°K, annealed for 10 days at 453°K, and annealed for 100 days at 413°K. The three heat treatments resulted in the same lattice parameters at room temperature. None of the specimens showed any superlattice lines. The lattice parameters of this alloy were also measured at temperature from 77° to 750°K. An anomaly in the temperature variation of the lattice paramete.rs occurs in the region near 400°k, which may be associated with local ordering. FROM measurements of the diffuse scattering of X-rays, it is known that the [ phase in the system Ag-A1 near the stoichiometric composition Ag2A1 ex- hibits a considerable degree of short-range order at room temperature.&apos; Moreover, based on the position of the short-range order peaks a superlattice model had been proposed in the same study and it was suggested that lowering the annealing temperature to 420°K might result in long-range order. In the present study, the diffraction patterns and the lattice parameters of three differently heat-treated specimens, i.e., quenched from 825°K, annealed for 10 days at 453°K, and annealed for 100 days at 413°K, were determined from 77" to 750°K. The purpose of these measurements was to investigate 1) whether long-range order could be established by prolonged annealing and 2) whether the lattice parameters at room temperature depended on the heat treatment, since it had been proposed earlier2 that the lattice parameters in this phase are related to the atomic arrangement. 1) EXPERIMENTAL TECHNIQUES Silver and aluminum, both 99.99 pct purity, were melted in a zirconium oxide crucible under helium in

Jan 1, 1969