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By Paul Billingsley

THE mining districts of the first and second order1 of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of Tertiary compres-sive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 NATURE OF THE THRUST ARC The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The cross-sections are as shown in Fig. 2.

Jan 1, 1933

By G. S. Hume

Three provinces in Canada—New Brunswick, Ontario and Alberta— produce oil and gas in commercial quantities. In addition a small amount of oil is being produced and refined in the Northwest Territories at Norman on the Mackenzie River. The production at Norman is derived from two wells drilled by Northwest (Imperial Oil) Co. in 1920 and 1923. The refined products of the oil are used locally in connection with mineral developments on Great Bear Lake. The production of petroleum by provinces and the consumption of natural gas are shown in Table 3. In addition a small amount of natural gas is produced in the southwestern part of Manitoba from shallow wells for local use. Tables 1 and 2 give detailed information. The greatest drilling activity in 1933 in Canada centered around the southern end of the Turner Valley field, Alberta. In addition to several wells previously commenced in this area, eleven new wells were begun. There were three completions to the Paleozoic producing zone in 1933 in the southern part of Turner Valley and one well was abandoned as a result of being off the favorable structure. Of two wells completed in

Jan 1, 1934

By Charles White Merrill

A forecast of mineral demand during the remaining years of the 20th century can serve as an excellent starting point for student mining and mineral engineers in planning their professional careers. This approach of appraising demand before seeking supply is not new. of course, but, it is quite the opposite of the traditional attack on mineral resources in which adventurous prospectors, followed by practical miners and engineers, have in the past sought out and developed mineral supply with a faith that markets existed for the products they were preparing to offer. Such faith, even to this day remains fully justified if the product is gold, which still enjoys an unlimited market at $35 a fine ounce, but other mineral products must compete in markets of varying stability and capacity for adsorbing new supply. The world is in a period of rapid expansion. Most basic is the worldwide increase in the number of people which has reached proportions popularly termed "the population explosion." Conservative demographers, noting an increase from 1 ?h billion people at the beginning of the 20th century to 3 billion today, are predicting 5 billion by the year 2000; some predictions are much higher.

Jan 2, 1964

On Feb. 16, 1948, the Board of Directors of AIME authorized the publishing of "Technical Notes" in METALS TECHNOLOGY. The purpose is to provide prompt publication of wry short items of the following general types: 1. Results of short investigations which do not warrant a paper. 2. The conclusions of extensive investigations of insufficient general interest to justify a regular paper. 3. Conclusions arising in the course of an investigation, which, because of interest to others in the field, the author wishes to present prior to completion of the investigation. 4. Pertinent factual comment (not mere argument) on the subject matter of previous "Notes." Such Notes will be subject to the approval of the Auxiliary and AIME Publications Committees, but can be handled more promptly than regular papers because they need not be referred to readers. The recommended maxi- mum length is 500 words; notes in excess of 1,000 words will not be considered for this type of publication. A graph or photograph may be included as part of the note when particularly illustrative. As with regular papers, contributions to the new section should be submitted to the Secretary of the AIME.

Jan 1, 1948

By H. Reginald Hardy, Gary L. Mowrey

Field studies were conducted over a longwall coal mining operation to investigate the feasibility of using microseismic techniques to detect and to locate any areas of instability in the vicinity of the longwall. An array of geophones buried at depths of 3 to 8 m from surface were positioned approximately 130 m above the active area of the longwall panel. A mobile microseismic monitoring facility amplified, filtered, and recorded the microseismic activity sensed by the geophones. Microseismic events were detected at depths of at least 130 m and at horizontal distances in excess of 250 m from the source. Most events, which resembled decaying sinusoidal transients, had frequencies of 10 to 100 Hz, and particle velocities of 1 to 8 pm/s. Source locations for the 150 largest events were computed using a least-square travel-time-difference method. Both isotropic and unique wave propagation velocity models were considered when evaluating the source locations. Most of the events were computed to be within ± 30 m vertically of the coal seam and ± 15 m horizontally of the longwall face, when the unique velocity model was employed.

Jan 1, 1980

By C. H. Wayman, D. W. Fuerstenau

THE gas phase is one of the indispensible ingredients in flotation operations. Flotation depends on the collision of an air bubble and a mineral particle in a pulp and their ability to remain in contact long enough for adherence to take place. Before it is possible to understand the mechanics of air bubble-mineral particle encounter, it is necessary to learn more about the nature of bubbles themselves before collision with a mineral particle has taken place. To date, little work has been done on air bubbles in flotation systems. In 1945 Fahrenwald1 presented a study of the role of frothers on air bubbles and on aeration in flotation, and recently Wark and Sutherland2 discussed the work of Rosenberg3 in relation to flotation. The research reported in this present article was undertaken to investigate systematically the effect of bubble size and the concentration of certain reagents on the terminal velocity, shape, path, and drag coefficient of single bubbles in distilled water. Most of the work is concerned with the effect of a-terpineol on bubble motion in water, but studies were made with potassium chloride, potassium hydroxide, potassium ethyl xanthate, and potassium amyl xanthate.

Jan 6, 1958

By Paul H. Johnson

Chemical mining may be defined as the use of chemicals in extracting metal values from in situ broken or unbroken ores within a mine. The present means for the generation and regeneration of sulfuric acid or sulfuric-ferric sulfate solutions are inadequate for most applications. This report describes a pressure oxidation process for the generation and regeneration of these solutions from pyrites and spent iron sulfate leach liquors. While recent mining developments such as solution injection, caving, and conventional and nuclear blasting, have provided new and better means for the per-colation of leach solutions through rock masses, little has been done to reduce cost and improve the quality of the leach solutions that are required. A leach solution for chemical mining should meet certain requirements. It should be 1) inexpensive on either a small or large tonnage basis, 2) capable of selectively leaching the desired ore minerals contained in a particular ore, 3) of the proper strength or quality to do the job of leaching in an underground environment and 4) amendable to simple and inexpensive metal recovery steps. It is also important that the capital investment be low for the solution generation and; or regeneration plant.

Jan 8, 1965

By H. J. Levinstein, W. H. Robinson

A method of chemically polishing silver for metal-lographic examination has been developed. The samples are prepared by polishing on 0, 2/0, and 3/0 paper. They are then polished on 600 micro-cut paper, followed by a final mechanical polish on a cloth containing 5µ diamond paste. The samples are then chemically polished in a solution of 100 cc of saturated chromic acid and 5 cc of a 5 pct HC1 solution. The chemical polishing is performed by swabbing with a cotton ball saturated with the solution. During the chemical polishing, the sample is rinsed frequently in running water. Polishing in this manner for 5 min is sufficient to remove the strained material from the previous polishing operations. The amount of material removed is approximately 4µ/min. The surface obtained is flat and free of pits. Fig. 1 is an interference micrograph of a silver surface polished by this technique. If the solution employed is of improper HC1 content, an interference color film will form on the sample. This film can be removed either by swabbing with a cotton ball saturated with ortho-

Jan 1, 1962

By T. A. Read, M. S. Wechsler, D. S. Lieberman

IN the formation of martensite in steel, it has been observed that the habit plane does not change continuously as the alloy content is varied. Instead, it appears that discrete habits correspond to certain ranges of composition. Greninger and Troiano' found that in low-, medium-, and high-carbon steels, the habits are approximately (1l1), (225), and (259), respectively.* The work of Mehl and Van Winkle2 indicated that the change from the (225) to the (259) habit is fundamentally a consequence of the lower transformation temperature rather than the higher carbon content. Also, Otte and Read3 observed that the habit plane orientation for a chrome-carbon steel scattered within a cone of semivertex angle of 5 deg, which was outside of the experimental error in the determination of the habit plane. These observations suggest the importance of investigating what factors in the crystallography of the formation of martensite account for the several types of habit and the inherent scatter in the precise orientation of the habit plane. A theoretical treatment of the austenite-martensite transformation has been given,4 which considers the total transformation distortion to be composed

Jan 1, 1961

By E. C. Reed

Oil was discovered in Nebraska on Nov. I, 1939, when the Pawnee Royalty Company's Boice No. I well, about 3 miles west of Falls City (NE 1/4 NE 1/4, sec. 18, T.r N., R.16 E., Richardson County) was drilled into the Hunton formation but the develop-ment of the area took place during 1940. After a pumping test lasting 18 days, the Boice well stopped producing and failed to qualify for the State bonus of $ 15,000 offered for the first oil well to produce go bbl. per day for 60 consecutive days. On May 9, 1940, the Pawnee Royalty Company's Bucholz No. I well was completed about M mile southeast of the discovery well and flowed at the rate of about 330 bbl. per day, easily meeting the State bonus requirements. In addition to the discovery well, which later was reconditioned, and the bonus well, 28 producers were drilled in the Falls City field during 1940. Of these wells, 23 are in sec. 20, two are in the northern part 'of sec. 29, two in the southwestern part of sec. 17 and three in the eastern part of sec.

Jan 1, 1941

By E. C. Reed

Oil was discovered in Nebraska on Nov. I, 1939, when the Pawnee Royalty Company's Boice No. I well, about 3 miles west of Falls City (NE 1/4 NE 1/4, sec. 18, T.r N., R.16 E., Richardson County) was drilled into the Hunton formation but the develop-ment of the area took place during 1940. After a pumping test lasting 18 days, the Boice well stopped producing and failed to qualify for the State bonus of $ 15,000 offered for the first oil well to produce go bbl. per day for 60 consecutive days. On May 9, 1940, the Pawnee Royalty Company's Bucholz No. I well was completed about M mile southeast of the discovery well and flowed at the rate of about 330 bbl. per day, easily meeting the State bonus requirements. In addition to the discovery well, which later was reconditioned, and the bonus well, 28 producers were drilled in the Falls City field during 1940. Of these wells, 23 are in sec. 20, two are in the northern part 'of sec. 29, two in the southwestern part of sec. 17 and three in the eastern part of sec.

Jan 1, 1941

By J. Weertman

High-temperature creep experiments were carried out on indium, lead, and on binary substitutional alloys of In-Pb, In-Sn, In-TI, In-Cd, In-Hg, Pb-Bi, Pb-Sn, Pb-In, and Pb-Cd. The stress at which the power law creep equution breaks down was found to be much smaller for indium and lead than for metals with larger elastic moduli. The exponent over the stress in the power law creep equation was found to decrease upon alloying from values close to 4.5 to values near 3. THIS paper describes a set of high-temperature creep experiments made on high-purity lead and indium and on lead-rich and indium-rich single-phase binary alloys of various metals. These ex- periments were carried out to check two predictions of some creep equations derived by us"2 from a dislocation creep model due essentially to Mott. This model is shown in Fig. 1. Here dislocation loops are emitted from sources, not shown, situated on different slip planes. As the loops expand they come into each others' stress fields and are stopped. However, at high temperatures, as Mott has pointed out.

Jan 1, 1961

By A. K. Sinha, K. M. Sinha

Several studies concluded by various agencies (Coal Outlook, 1982; Malhotra, 1977) indicate that both the national and international markets for utility coal, which have been growing in recent years due to the uncertainties in petroleum supplies, will continue to grow in the foreseeable future. The areas where the Gemand for utility coal is projected to increase sub- stantially lie close to the midwestern coal fields, in the southeastern US, and in western Europe. Illinois has all the elements necessary to become an important exporter of thermal coal (Library of Con- gress, 1981) provided the coal is desulfurized to meet the environmental restrictions. Because of its high energy content, Illinois Basin coal, if desulfurized, has great potential for competing in the utility markets both nationally and internationally. Sulfur in coal occurs in organic and inorganic forms. The inorganic sulfur in Illinois coal is almost exclusively pyrite. The pyrite can be liberated by grinding and removed from the coal by such techniques as froth flotation. The Illinois Basin coals reportedly contain (Gluskoter and Simon, 1968) an average of 3.57% sulfur. Out of this, 2.06% is pyritic, 0.08% is sulfate, and 1.46% is organic sulfur.

Jan 1, 1986

By F. V. Tideswell

THE suggestion, which appears to find increasing favor, that the elementary composition of coals should be used as the basis of their classification, makes it important that our methods of expressing this elementary composition should be refined. It is doubtful whether many published ultimate analyses of coals are accurate within 1 per cent. carbon. Many are probably as much as 3 or 2 per cent. in error in carbon. It is, perhaps, not always realized that the extreme variation in carbon content over the range of bituminous coals is but 16 per cent. An error of 1 per cent. in carbon on analysis corresponds therefore with one-sixteenth of the whole range, an amount which is unjustifiable even for the application to commercial needs of a system of classification based on ultimate analysis. For the purposes of scientific research such limited accuracy is of little value. The object of this paper is to examine one important source of error in ultimate analysis, that due to the occurrence in coal of inorganic material, and to emphasize the need for the quantitative measurements (of carbon more particularly) on coals to be rendered independent of their contents of such material.

Jan 1, 1928

By L. C. De Jong, J. F. Shirley, M. L. Campbell

The Toquepala concentrator of the Southern Peru Copper Corp., located approximately 720 miles southeast of Lima near the Chilean border, processes 36,500 tons of ore daily containing between 0.50% and 3.00% copper. The molybdenite content in the ore also varies greatly, ranging from essentially nothing to as high as 0.15%. The 1966 yearly averages were approximately 1.20% copper and 0.03 % molybdenite. The three basic problems that plague the opera- tion of any molybdenite recovery plant are all present at Toquepala in large measures. Both the quantity of plant feed and the quantity of molybdenite contained in the plant feed are continuously changing. Even more detrimental to an efficient operation is the fact that the copper mineralization in the feed frequently changes once in every 24 hours and occasionally once a shift. From the point of view of the molybdenite plant metallurgist, there are four distinctive chalcopyrite concentrates and, at least, an equal number of chalcocite concentrates treated in the molybdenite recovery circuit. The various types of concentrates are distinguished mainly by their mineral content and how effectively the copper minerals are depressed by the different reagents used in the circuit.

Jan 9, 1967

Edward S. Simpson, Perth, Western Australia (communication to the Secretary): In 1896 the East Coolgardie gold-field was divided into three fields, viz. : Area, square miles. Officia1 Centers. (1) East Coolgardie,. . 634 Kalgoorlie. (2) Broad Arrow,. , 588 Kurawa. (3) Northeast Coolgardie,. 22,960 Kanowna. The whole of the area embraced by the eastern gold-fields is covered with late Tertiary sands and gravel, with occasional beds of clay shales. These mostly overlay granite which occasionally shows through in small round hills. At Coolgardie, Kalgoorlie and other mining centers, belts of diorite, serpentine and highly metamorphosed sedimentary rocks appear on the surface. The rainfall at Kalgoorlie in 1897 was 4.75 inches. That the climate has not always been so arid is evidenced by the recent discovery at Coolgardie (only twenty-five miles away) in the late Tertiary formations of a thick bed of brown coal, containing numerous fossil fern-leaves. As assayer and mineralogist to the Government of Western Australia I have had occasion to examine a large amount of the Kalgoorlie ores, both in Perth and at the mines at Boulder itself. The only tellurides I have been able to determine are

Jan 1, 1899

By O. J. Hassel, W. T. Maidens, J. H. Calbeck

The rotary gas fired reheating furnace used by the American Zinc Oxide Co. at Columbus, Ohio for Therotarygasfiredreheatingfurnacerefining lead-free zinc oxide is described. The outstanding features of this operation are that the color of the zinc oxide is greatly improved, sulphur is eliminated, and cadmium arethatrecovered without densifying the product to an objectionable degree. IN 1919 Leland S. Wemple obtained a patent for a process of reheating zinc oxide wherein the "coarsening of grain due to excessive heating was avoided." He taught in his specification that if solid carbonaceous material, such as lamp black, was added to the zinc oxide in proper amounts prior to reheating, objectionable sulphur compounds could be removed and the color would accordingly be improved and no objectionable densification would occur because of the relatively low temperature required. The situation that made this invention imperative was the newly opened zinc oxide plant of the American Zinc, Lead & Smelting Co. in Hills-boro, Ill. This was one of the early Western Type American Process zinc oxide operations. Characteristic of all of these early Western operations using Tri-State and Western ores was the great difficulty encountered in obtaining a product low enough in sulphur to compete with the Eastern Type American Process zinc oxides which were made from ores containing very low sulphur percentages. Wemple demonstrated that the refining process of his invention produced a superior color and although this was true and a most welcome feature, the primary purpose of the early refining operations at Hillsboro was to reduce substantially the high sulphur content of the crude zinc oxide. Although many and varied attempts had been made for refining zinc oxide none of the processes had a commercial history of any consequence until Wemple's invention became standard practice for the American Zinc, Lead & Smelting Co. in 1919 and their operations have been unique in that substantially all of their lead-free zinc oxide has been reheated since the first installation at Hillsboro. This process has become known in the industry as refining. The furnace developed by Wemple and continued in use by the company from 1919 until 1943 was unusual and merits some consideration by way of review in this paper. The furnace was essentially a double hearth coal-fired muffle furnace with a mechanical raking system consisting of a central shaft supporting six rabble arms in each muffle. The untreated or "crude" zinc oxide was fed onto the outer rim of the top muffle, moved to the center where it dropped to the lower muffle and progressed to the outer rim where it was discharged into an alloy screw conveyor. The retention in this furnace was extremely short, about 5 min, and the shallow zinc oxide bed on the hearths of the muffles was being continuously turned by the fast moving rabbles. Soft coal was burned on the grates below the lower muffle and the long yellow flame necessary to carry the heat around both muffles resulted in a very inefficient combustion of the fuel. The temperature of the top of the lower muffle seldom exceeded 65 °C although the oxide itself often reached 700°C before discharge. The capacity of this furnace was approximately 1/2 ton per hr. In our plant at Columbus it was necessary to keep four of these furnaces running in parallel to take care of the production because, as mentioned above, every pound of zinc oxide produced during these 24 yr passed through one of these refining furnaces. An essential part of this refining operation was the use of carbonaceous material admixed with the zinc oxide fed to the furnaces. Between 1 and 2 pct of a bran produced in the processing of cotton seed was added to all zinc oxide charged to the furnaces. The bran ignited on the top hearth and was still burning when the charge fell from the top hearth to the bottom hearth making a cascade of sparks. The rapid turning of the zinc oxide caused these particles of bran to flash on the hearths behind each rabble; but the combustion, of necessity, had to be complete by the time the charge reached the outer rim of the bottom hearth, otherwise the finished product would be contaminated with the charred particles of bran which would give the zinc oxide an unsatisfactory color. Although this operation was initiated to reduce objectionable sulphur percentages, as time went on new properties of the product were appreciated which made advisable continuing the refining process long after other methods of sulphur reduction became known in the industry. The particle size and particle size distribution, the absence of colloidal fines and perhaps a unique surface condition gave this product an outstanding performance when used in paints. The Wemple furnaces installed in Columbus in 1919 had to be rebuilt frequently and were extravagant in the use of fuel. The raking mechanism and the muffles required excessive maintenance expense and as the furnaces wore out the problem arose whether to continue along this line or to explore the possibilities of obtaining similar or better results in the simpler and more commonly used rotary furnace. To this end special research was initiated in 1941 on a small laboratory rotary

Jan 1, 1951

By Sultan Amerie

PERSIA looms up more prominently each year as one of the richest oilfields in the world. The actual production in the south and the possibilities in both the north and the south are very great. The output in the south, where the Anglo-Persian Oil Co. operates a wide concession, is steadily increasing, the returns for the fiscal year 1922-23 being 2,957,028 tons. The estimated production for. 1923-24 is 3,775,000 tons. The figures for the past few years have been as follows: 1918-19 1,106,415 tons 1920-21 1,743,557 tons 1919-20 1,385,301 tons 1921-22 2,327,221 tons According to the company's last annual report, the production from the -Persian fields operated by its subsidiaries has been well maintained and is now being increased to deal with the expanding off-take of the company's refineries at Abadan, Persia, and Dandarcy, Wales. Test drilling in an entirely different area in Persia indicates the existence of a new oilfield, which it is intended for the time being to hold as a reserve.

Jan 3, 1924

By D’Arcy A. Shock

In this year's review, the concept of solution mining has been expanded to include total solution as well as the technology of leaching, or partial solution methods. Leaching methods continue to make strides in the processing of metallic minerals, particularly in copper and uranium production. No quantitative data are available on the increase of leach operations; however, it is known that there were more systems installed in 1969 and that the estimated 15% of U.S. domestic production of copper produced in 1968 was by leach methods.1 While the number of publications appearing during the year were few,2,3 there were special sessions in this field at the AIME Annual Meeting and SME Fall Meeting in 1969 and more scheduled for these meetings in 1970. Significant areas that should be mentioned are: the continuing interest in bacteria to convert sulfide sulfur to acid thus reducing reagent costs in both copper and uranium sulfide ores, the exploration of leaching agents other than common mineral acids or alkaline solutions,4,5 kinetic studies of leach mechanisms and the development of microfractures for increased leach solution penetration by use of chemical or atomic explosives.6,7

Jan 1, 1970

By J. Th. G. Overbeek, R. Schumann, P. L. De Bruyn

THE technique of concentrating valuable minerals from lean ores by flotation depends upon the creation of a finite contact angle at the three-phase contact, mineral-water-air. If the mineral is completely wetted by the water phase, contact angle zero, there is no tendency for air bubbles to attach themselves to the mineral. However, when the contact angle is finite, the surface free energy of the system, water-air bubble-mineral particle, can be diminished by contact between the bubble and the particle, and if not too heavy the mineral will be levitated in the froth. With a few exceptions, all clean minerals are completely wetted by pure water. Thus the art of flotation consists in adding substances to the water to make a finite contact angle with the mineral to be floated, but to leave the other minerals with a zero contact angle. The contact angle concept and experimental measurements of contact angles have played important roles in flotation research for several decades.1-3 Nevertheless, there remain unanswered some basic questions as to the scientific significance of the contact angle and the nature of the processes by which flotation reagents affect contact angles.

Jan 5, 1954