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By G. S. Scott, H. G. Turner, W. L. Kleene

It is well known that different forms of carbon show differences in chemical behavior under apparently identical conditions. It is fairly well known that these differences persist, although to a lesser degree, in a single group of carbons, such as the anthracites of Pennsylvania. It is the purpose of this paper to show the extent of these variations for Pennsylvania anthracites from actual quantitative measurements of the amount of carbon dioxide reduced under the standardized test conditions employed. As the amount of carbon dioxide reduced to the monoxide (under comparative conditions termed, for convenience, the "reactivity") is important in combustion, gas production and metallurgy, it is hoped that this paper will be a useful contribution to the store of knowledge on these subjects. In carrying out the investigation, considerable time and thought were spent in obtaining what seemed to be the best possible design of apparatus. The next step consisted in making a number of trial runs on the same sample, varying temperature, particle diameter, etc. and then outlining a standardized procedure to be followed in testing all samples. Fifty anthracites were tested. As a matter of interest, some 10 miscellaneous samples were also tested. The data show initial reaction temperatures (abbreviated I.R.T.), reaction velocity constants at 900" and 950" C., some effects of added substances, and a few additional tests designed to throw some light on the causes of differences in reactivity. The sample of charcoal, as was anticipated, proved to be easily the most reactive of any sample tested. The anthracites as a group came second. The five samples of gas and by-product cokes, obtained from five different coke manufacturers, came third, and a single sample of Rhode Island anthracite ranked fourth, with respect to reactivity as above defined. Although the five coke samples do not necessarily represent the average market coke, and five samples constitute a rather small number of samples to serve as a basis for comparisons, the fact that none

Jan 1, 1934

By W. P. Rawles

In the foreword by C. K. Leith, Chairman of The Mineral Inquiry, it is pointed out that the ordinary mineral production tables do not show the commercial control, and that some knowledge of the situation is desirable as a background for the consideration of problems involving mineral raw materials. The report consists principally of tables, accompanied by a brief text, giving the production and an analysis of the control, according to nationality, of 18 minerals: aluminum, chromite, copper, iron and steel, lead, manganese ore, mercury, molybdenum, nickel, nitrates, petroleum, potash, silver, sulfur, tin, tungsten, vanadium, and zinc. For the most part, the production figures for 1929 and the latest figures for reserves have been used. When feasible, the control has been shown at the various stages of production; mining, smelting and refining. American capital was dominant in the production of 10 mineral commodities, including six of the most important; British capital, in four instances; while Spanish, German, Chilean or Chinese interests cach led in the control of one. British, French, German, and Dutch capital occupied second place in the control of most of the important minerals. Between two-thirds and three-fourths of the world's mincral production is controlled by British and American capital.

Jan 1, 1934

By C. E. Shoenfelt, D. E. Winchester

NO important discoveries of petroleum during 1933 were reported from New Mexico. Lea and Eddy counties were the centers of activity during the drilling season and each had a number of interesting completions. The Hobbs pool, in Lea County, was definitely outlined on the east, north and northwest. Under an agreement reached last summer by state officials and operators, the Hobbs pool was continued under proration throughout the year. One hundred eighty-four units of 40 acres each were being produced at the end of 1933. The allowable was 21,306 bbl. daily at the beginning of 1933, but when the agreement was revised in the spring the minimum was raised to 30,000 bbl., and by the end of the year had been raised to 33,473 bbl. At present the field is being prorated on the basis of 25 per cent on acreage and 75 per cent on potentials except in the southwestern edge of the field, where water encroachment is a problem. In this area the basis of proration is 40 per cent on acreage and 60 per cent on potentials. A corrective method employed in this part of the field has been partly successful. The water is advancing in the upper part of the pay, a dolomitic limestone, and in a number of instances packers have been set in the pay below the water and above the oil. The locating of a satisfactory seat for a packer is difficult and in some instances has not been a complete success. Pipe line runs from the field during the year aggregated 11,413,218 bbl., bringing the total gross production up to 41,093,681 bbl., of which 39,000,-000 bbl. has been produced under proration, which went into effect on July 10, 1930. On Nov. 30, potentials were determined on the assigned pressure basis and the total was reduced 71,165 bbl. daily, to 1,265,-332 barrels. The outstanding completions in the Hobbs pool were three in number, of which the best was the Humble Oil & Refining Company's No. 3B Bowers in sec. 20, 18S., 38E., with an initial production of 11,664 bbl. of oil and 10,000,000 cu. ft. of gas. The Shell Petroleum Company's No. 4B McKinley, in the same section, produced at the rate of 22,940 bbl. of oil while flowing open, but when tubed, flowed at the rate of 6610 bbl. The third outstanding well, No. 4 Hardin of the Tidal Oil Co., and located in

Jan 1, 1934

By V. R. Garfias

With the exception of the United States and Russia, none of the leading world powers have within their boundaries the oil supplies needed to meet present peace-time requirements, and even in regard to the United States it is admitted by competent observers that the known oil reserves within the country are inadequate to meet demands for more than a comparatively few years. It follows, therefore, that the transportation of petroleum—almost entirely by tank steamers—from foreign fields to the main consuming centers is one of the most important factors affecting the present and future development of the oil industry. The world-wide distribution of petroleum is affected by numerous factors of which international politics is not the least important. The assurance of an ample supply of petroleum—one of the most essential munitions of war—is of paramount importance particularly to those countries subjected to the rivalries of powerful neighbors. And paralleling the importance of the control of an ample supply is that of its safe transportation from the fields to the consuming centers. To illustrate: France is dependent almost entirely on foreign sources for its petroleum requirements estimated at close to 100,000 bbl. daily, and in order to control such a supply after the World War it acquired an interest in the Iraq oil fields. Lately it has undertaken the construction of a pipe line from these fields to the Mediterranean seaboard in Syria with the expectation that late in 1934 these fields will supply between 30 and 40 per cent of the country's requirements. It should be noted, however, that the availability of this supply is entirely dependent on the safe operation in the Mediterranean at all times of an adequate fleet of tank steamers. Thus, in order to transport 40,000 bbl. daily, it will be necessary for one 10,000-ton tanker to leave Tripoli, the Syrian port, say for Marseille, every other day throughout the year while to meet the entire present peace requirements of France from the Iraq fields, a fleet of some 30 such tankers must be kept in continuous operation between Tripoli and Marseille.

Jan 1, 1934

By A. Hasselbring

Sub-Level stoping was used in this country at least as early as 1912, at the Magpie mine in Michipicoten. The fundamental principles of the system are the same wherever it is used, but modifications have been adopted in the Michigan iron mines and in several Canadian mines. It is a system whereby a suitable body of ore may be developed quickly and worked cheaply, with a low initial expense, and by miners of quite ordinary ability. The basic method, described in the following pages, may be modified to meet conditions where one or more factors are not in accord with normal sub-level stoping requirements. In suitable ground, sub-level stoping is probably the most satisfactory method yet devised for underground hard-rock mining. It is so simple, straightforward, and safe that no special training of a crew is necessary. Any miner capable of drifting and raising can carry on the work necessary for sub-level stoping after the shaft has been sunk. The method is suitable, however, only for reasonably wide ore-bodies, the minimum width of ore to which it can be economically applied being somewhere in the neighbour-hood of thirty feet. The development programme is simple. Assuming, for purposes of illuslustration, an ideal ore-body, two thousand feet long, dipping nearly vertical, and varying in width from forty to a hundred feet, this programme would be as follows. The shaft should be sunk on the footwall side about sixty feet outside of the ore-body and near its centre. Levels are then established at suitable intervals, usually 125 feet. On each level, a cross-cut is run to the ore-body, and there a main-haulage drift is driven in either direction to the end of the ore. Cross-cuts are then run at 25-foot intervals, so that ore-chutes can be spaced about 25 feet centre to centre each way. It is not necessary that these cross-cuts be extended to the walls of the ore-body, if the position of the walls is known; they are extended just far enough to make room for the correct location of the chutes.

Jan 1, 1934

By F. H. Parsons

At the time that converting or bessemerizing of copper matte first began to be practiced by the smelters in the copper industry, converters were lined by tamping the flux, usually siliceous ore, into the steel shell. About 1910, practice in several plants had demonstrated the superiority of a basic lining of nonfluxing material and the addition of flux through the mouth of the converter. Adoption of the new method by nearly the entire industry followed. Basic linings are made of refractory "magnesite" brick manufactured, usually, from imported dead-burned magnesite. Either the linings are laid up in the shell dry or the bricks arc bonded with some mortar dictated by the preference of the user. Foreign, usually Austrian, magnesite was the main source of supply for these bricks, although there were domestic sources, but it was not until costs began to rise a few years after the first use of basic linings that these domestic sources were investigated to any great extent. Exigencies created by the World War necessitated the use of the domestic magnesite during this period, but the brick manufacturers reverted to the use of the foreign product after the war, because the impurities therein made a brick with a better fire bond than the purer domestic magnesite. Therefore the domestic product became available at a favorable price for any metallurgical process that permitted its use. The United Verde converting practice using magnesite linings has resulted in a high consumption of magnesite because of the zinc content of the low-grade matte. It was realized that the cost of these linings represented a large portion of the cost of converting, and an investigation was started to find means by which these costs might be lowered. In the neighboring state of California rather pure magnesite was being mined and treated for the market. The product, however, was purposely made to simulate the dead-burned grain magnesite product from foreign sources by the addition of fluxing impurities before burning. It was learned that this dead-burned California grain magnesite could be laid down in Arizona at a price one-third that of the same tonnage of "magnesite" brick manufactured from foreign magnesite. It was also learned that at least one California producer was ready to supply the market with periclase, which was a grain magnesia produced by burning the

Jan 1, 1934

Mining Methods GERALD F. SHERMAN, Chairman JOHN A. CHURCH, Vice-chaiman CHARLES W. WRIGHT, Secretary Alluvial Mining CLINTON BERNARD CHARLES JANIN H.R. NORSWORTHY Open-cut Mining Iron MAX H. BARBER J. A. MACKILLICAN Copper MICHAEL CURLEY R.B. TEMPEST Underground Mining Iron C. H. BAXTER TENNEY C. DESOLLAR

Jan 1, 1934

By H. S. Martin

The Phosphate Recovery Corporation operates three flotation plants, NOS. 1 and 2 concentrators about three miles northeast of Mulberry, Florida, and No. 3 plant at Wales, Tennessee. These plants represent the first commercial phosphate flotation operation and are also believed to be the largest nonmetallic flotation operation in the world at the present time. The details of this paper will be confined to plant No. 2, this being the newest and largest concentrator in Florida, and the flow sheet being practically the same as at plant No. 1. The No. 3 plant has been operated but a short time and has been shut down since December, 1932, on account of the decrease in phosphate rock production. The phosphate washers usually are located centrally on a known deposit so that about two hundred acres of ground can be mined economically to each washer location. The washers are moved to new areas when the distance becomes too great for economical pumping. The flotation plants are built either adjacent to a washer, so that current debris may be utilized, or on the site of a former washer where there is sufficient accumulated debris available for mining, and the flotation plants must also be moved from time to time. Most of the water used in the Florida flotation plants is recovered after passing through a circulating system where most of the fine SUSpended matter is settled out, but some make-up water is obtained from deep wells near the plant. Power is obtained from the Tampa Electric Co. through the distribution facilities of the International Agricultural Corporation. Flotation concentrate is hauled from the plant by trolley over the International Agricultural Corporation's trolley system, to the drying plant at Prairie, one mile northwest of Mulberry. Ore Treated In the pebble phosphate district of Florida, the phosphate mineral, or collophane, is usually found in horizontal beds of varying thickness

Jan 1, 1934

By Irwin Roman, Thomas C. Serman

It has been known for many years that when a wire is moved in a magnetic field, an electromotive force is developed which is proportional to the rate at which the wire is moved in a direction perpendicular to the magnetic intensity and to the magnetic intensity itself. If the ends of the wire are connected to a current indicator, the current behaves exactly as though the source of electromotive force were a galvanic cell. If a wire is wound circularly and rotated uniformly around a diameter not parallel to the intensity, the current flowing through the wire will be alternating of sinusoidal shape. If, instead of a single loop, there are several turns wound in a short helix, the electromotive force developed will be approximately proportional to the number of turns, the area of the helix and to the speed of rotation. The maximum electromotive force will be developed when the axis of rotation is perpendicular to the field; if this is not so, only the component of the intensity that is perpendicular to the axis of rotation is effective. This is the principle of the usual earth inductor. With a few turns of wire and comparatively slow rotation, it is possible to produce a considerable deflection of a galvanometer. If two similar coils are rotated together at two different points for which the magnetic field intensities perpendicular to the axes of rotation are different, the electromotive forces developed will each depend on its corresponding intensity and be a measure of that intensity. If the intensities are sufficiently different so that the electromotive forces may be compared, the two intensities may be compared. This is the principle

Jan 1, 1934

By William Daly

THE application of artificial refrigeration, or air-conditioning, to the ventilation of deep, hot mines has long been a subject of interest to the operators of such properties. Artificial cooling of the air in theaters, railroad coaches, and various industrial plants has been so successful within recent years that it has been natural to assume that the adoption of similar methods would afford a ready solution to the difficult problem of mine ventilation. It should however, be obvious, that although there may be nothing technically impossible in the application of this process to mine ventilation there is a great economic distinction between the maintenance of a high standard of comfort for a large number of people in a relatively small space such as a theater and the cooling of air to improve working conditions for miners scattered throughout the extensive workings of a large mine. Many methods of air-conditioning have been considered by the management of the Anaconda Copper Mining Co. at various times, but until the development of the process to be described in this paper none has seemed economically practicable.

Jan 1, 1934

By R. V. Whetsel, V. R. Garfias

The production of petroleum in Mexico during 1933 totaled 33,430,-000 bbl., or 625,000 bbl. more than in the previous year. This is the first time since the peak in 1921 that the declining trend of output has been reversed. Drilling activity in the proven areas of the Isthmus of Tehuantepec and the Northern fields increased substantially during the year. The completion of two producers in the Poza Rica area south of Tuxpam and a shallow gas well in the Camargo district near the American border were the outstanding features of development. Late in September the Northern fields and the oil port of Tampico were swept by a hurricane followed by floods which caused loss of life and heavy damage to the City of Tampico and to transportation, tank farms and refineries. For three weeks, owing to the silting of the Tampico Bar and destruction of terminal facilities, no oil could be shipped for export. About half the wells of the Northern fields were closed for a period of 30 days. The prompt and effective steps taken by General Macias, chief of military operations, prevented the spread of epidemics and any serious aftermath of the catastrophe.

Jan 1, 1934

By T. H. Miller

An attempt has been mace in this publication to present annotated references to all articles pertaining, to ore dressing that were published during 1931 and 1932; in a few instances reference is made to articles published prior to 1931 where the articles have not been included in previous bibliography appended to the annual statistical discussions of ore concentration published by the Bureau of Mines. Articles have been taken from more than 75 periodicals, journals, serials, etc., and 423 articles are abstracted herewith. A number of these abstracts, particularly those appearing in foreign publications, have been taken from Chemical Abstracts (published by the American Chemical Society, Easton, Pa.), the general use of which the authors wish to acknowledge. Other annotations were taken directly from the original publications. The entire field of ore dressing has been included in the bibliography and articles dealing with crushing, grinding classification, concentration, thickening, and filtration have been included, as well as on amalgamation, cyanidation, leaching, magnetic concentration, washing, etc., and on theory and laboratory operation. The articles are arranged in alphabetical order by authors. Lack of printing funds prohibited the inclusion of a subject index.

Jan 1, 1934

Jan 1, 1934

By E. R. Shorey

FLOTATION-Mill operator's have recognized that slimes are detri-mental to the flotation concentration of zinc ores. The, presence of primary slime in many of the Wisconsin ores is largely responsible for the failures experienced in treating these ores by flotation. These failures have discouraged the adoption-of the flotation process by opera-tors in the Wisconsin zinc district. The removal of slimes by decantation seemed to be the obvious way to meet the problem of treating slimy or' clayey ores by flotation. To facilitate the removal of slime, it was decided to mix the ore pulp with sodium silicate, which acts to deflocculate the pulp.1 Deflocculation causes slime suspension, making it possible to separate the slime from the sands by decantation.2 Since the literature contains little definite information on the use of sodium silicate to deflocculate ore pulps, a series of tests was conducted to obtain the necessary information. Tests to determine the settling rates of sand and slime in deflocculated pulps were conducted on a dolomite-marcasite-sphalerite ore ground to minus 80 mesh (175 microns) and mixed with water to form a pulp. The deflocculator3 was Mallinckrodt 40° to 42.5° Bé. liquid sodium silicate (Na20 + 3.25Si02). .By microscopic analysis the suspended slimes4 were found to be minus 15 microns (approximately 1000 mesh).

Jan 1, 1934

By Allen S. Smith

Analysis of the helium content of a natural gas presents more than the usual difficulties encountered in applying the thermal--conductivity method because of the relatively small amounts of this inert gas present and the wide variation in the other constituents. However, the numerous advantages of this method and its adaptability to continuously recording and control instruments make it worthy of consideration. A specific application of the method described yields quantitative results only when used with gas mixtures of known qualitative compositions which vary within predetermined limits. Periodic analyses for the helium content of a producing gas well may be conveniently made by an absorption method3/ and a continuous analytical method is not necessary for this purpose. Natural gas containing 1.75 to 1.90 percent of helium produced from Government-owned wells is processed in the Amarillo (Texas) Helium Plant of the Bureau of Mines. The helium extracted in the plant is supplied to the Army and Navy, and the processed natural gas is sold to a commercial gas company4/. As complete recovery of the helium in the raw material is not economically practicable, the processed gas contains 0.1 to 0.3 percent of helium, depending upon conditions of operation;- Production is checked against the helium removed from the gas, which before the installation of the thermal--conductivity apparatus was calculated from the analysis of a cumulative sample of the processed gas. As conditions of operation affect the residual helium content to a large extent, a composite sample was an uncertain index of the efficiency of the process.

Jan 1, 1934

By E. D. Gardner

This paper is the third of a series of three on placer mining in the western United States. The first paper4 discusses the history of placer mining in the Western States and the production of placer gold, geology of placer deposits, location of placer claims on public lands, sampling and estimation of gold placers, and classification of placer-mining methods, together with hand-shoveling and ground-sluicing. The second papers deals with hydraulicking, sluice boxes and riffles, recovery of gold and platinum from placer concentrates, treatment of amalgam, and marketing of placer gold. The discussion of sluice boxes and subsequent subjects in the second paper applies to all forms of placer mining. The present paper treats of dredging and other forms of mechanical handling of placer gravels, and drift mining.

Jan 1, 1934

By C. Schlumberger

THE object of this paper is to describe the adaptation of electrical resistivity measurements to the particular case of exploration in which the surface is an expanse of water (river, lake, sea). Water in itself does not constitute an obstacle to electrical exploration. It is merely an overburden, which is fluid instead of being solid, and as a consequence the routine of the measurements has to be modified. Also, in many instances, the liquid under consideration is highly conductive (salt water). This introduces an additional difficulty into exploration work, and has to be overcome by the geophysicist. We do not propose to discuss here the basic principles of electrical resistivity measurements, which have been dealt with in various previous papers,1 but will simply recall the two fundamental techniques which govern its field application: 1. Horizontal exploration, or method of the resistivity map, in which a series of electrical measurements are carried out at various stations, keeping the same electrode spacing. Thus, a horizontal layer of the subsoil, of a practically constant thickness, is explored. 2. Vertical exploration, or "vertical sounding?2 method, in which a series of measurements are made with increasing electrode spacings at one or several stations. In this way, the apparent resistivity is deter-

Jan 1, 1934

By F. N. Rhines

DESPITE the large amount of study which has been devoted to the subject our present knowledge of the copper-oxygen system remains incomplete and unsatisfactory in many respects. This applies particu-larly to those regions in which solid metallic copper exists. The primary object of the present paper is the contribution of new information relative to the solid solubility of oxygen (or cuprous oxide) in copper at atmospheric pressure, together with certain observations in the low-pressure regions of the system. It seems appropriate also to present a brief summary of the outstanding previous work on the constitution of mixtures of copper with its lowest oxide in order to show the relation between the new facts and the system as a whole. The earliest recorded investigations of the copper-oxygen system are those of M. S. Lucas (1) § and of M. Chevillot(2) in 1819 and 1820. Lucas believed that liquid copper is capable of dissolving its oxide, but neither he nor Chevillot was able to furnish convincing proof of this property. It was not until 1866 that T. Graham° definitely established the existence of such a solubility. Nine years later W. Hampe(4) measured its extent and roughly outlined the copper-rich portion of the system. The first really precise examination of the constitutional relationship between copper and cuprous oxide, however, was that of E. Heyn(5) who in 1900 published a temperature-concentration diagram covering the range from 0 to 10 per cent of cuprous oxide at atmospheric pressure. Within these limits of composition cuprous oxide was found to dissolve in liquid copper, forming at 3.4 to 3.5 per cent a eutectic which melted at 1065° C. R. E. Slade and F. D. Farrow(6) extended these studies to mixtures of higher

Jan 1, 1934

By M. L. Fuller

The fundamental mechanism of the deformation of zinc has been thoroughly described by several prominent investigators, particularly Mark, Polanyi, and Schmid,1 Mathewson and Phillips,2 and Schmid and Wassermann.3 The deformation of zinc occurs primarily through slip along basal planes (00.11, and secondarily through twinning on pyramidal planes of the form (10.2). In addition to these basic studies on single crystals, there have been a number of determinations4,5 of preferred orientations developed in rolled, polycrystalline zinc. In no case, to our knowledge, has there been described the development of oriented structures in zinc as a result of a systematic series of rolling treatments. The work included in the present paper shows the changes in orientation produced in a zinc alloy by successively increasing degrees of cold-rolling reduction. This alloy has the same crystal form, hexagonal close-packed, as zinc, but its susceptibility to hardening for a given degree of working is much greater because of its higher recrystal-lization temperature. Experimental Procedure Composition of the Alloy and Rolling Treatment The alloy used in this investigation consisted of zinc of 99.9 per cent purity to which 1 per cent of copper and 0.01 per cent of magnesium had been added.

Jan 1, 1934

By Roland D. Parks

To construct a yieldable metal prop of demonstrated practicability has been the aim of the writer of this article for a period of years. Such a prop is herewith described; it involves a yielding principle not previously utilized, to the best of the author's knowledge, in any of the numerous types of props which are in use in Europe and England or on record at the United States Patent Office.' No attempt will be made in this paper to analyze the situation in regard to the economics of timber substitutes. Suffice it to say that shortage of suitable timber combined with high freight rates has already presented a problem in some mining districts, and in the relatively near future will probably demand considerable attention from the mining industry as a whole. In order to understand the problems involved in the design of timber substitutes for underground support, it will be well to review briefly the fundamentals of ground subsidence and of the action of timber as props. The forces encountered in the support of mine openings are not computable. As a rule subsiding ground moves slowly; but it moves with an irresistible force. The only way to be certain of stopping ground movement is to completely fill up the openings below such movement. This is, obviously, an impracticability from the mining standpoint. The ordinary procedure is to put in timber to hold up the loose back and permit the natural arch above to resist its own loading. Under these conditions the timber rigidly supports the loose; but if the natural arch fails, the timber is then called upon to resist this additional pressure. Usually it cannot do this. The result is a crushing of the supports. Efficient timbering is that which will last just long enough to complete in safety the mining operations necessary to extract the ore. Wood has a cellular structure. It has great longitudinal strength for its weight. Further, it possesses the ability to maintain a high percentage of its strength while it is being crushed. In other words, it rigidly supports loads up to its capabilities and then continues to sustain

Jan 1, 1934