Search Documents

By Ezequiel Ordoñez

THE great activity with which the oil resources of the northern Cantons of the State of Veracruz have been developed has largely resulted from the great success obtained by the important explorations carried out since 1902 in the Ebano district in the North, and several years later near Tuxpam, in the South. It must not be thought that these successes were quickly obtained, since the preliminary studies by good experts, the acquisition of what were thought to be the most promising coast lands, the extensive clearing thereof, and finally the number of unsuccessful drillings at great depth, signified an original outlay of some ten's of millions of dollars before finding commercial oil. The discovery of oil in industrial quantities at Cerro de la Pez, Ebano district, and the famous Dos Bocas gusher some years later, which was burned, once and for all made famous the Veracruz coast, where today is concentrated the Mexican output of mineral oil. In .1917, this production was nearly 50,000,000 bbl. It is well known that this output represents only a fraction of what the wells in actual production can furnish, because with adequate means of transportation and storage, the present extraction could be somewhat over 300,000,000 bbl. a year. These enormous potential oil resources of the Veracruz coast proceed from a relatively small number of wells, scattered over a few oil fields, separated from each other by large unexplored areas, wherein may be found other favorable fields which, in time, will undoubtedly become just as great centers of oil production. Experts who know our Gulf Coast believe that lands with commercial oil resources lie not only between the Panuco amid Tuxpan Rivers, but that indications are that the oil zone of Mexico, with more or less interruption, takes in the coast zone from Northern Tamaulipas to the foot of the Sierra Madre of Chiapas, and the banks of the Usumacinta River. This generalization is not merely the outcome of optimism, but is the result of the persistency with which one finds, throughout this Gulf Coast, the most usual characteristics upon which we depend for recognizing oil-bearing lands.

Jan 5, 1918

By C. R. Boyd

THE region to which I have the pleasure of calling your attention, though limited in area, is remarkable for the quantity and purity of its mineral deposits, and in these respects it would be difficult to find its equal anywhere. IRON ORES. The red and brown hematites, pipe ore, and semi-magnetites, from which is made in charcoal furnaces the highest quality of iron for car-wheels, extend through the counties of Giles, Montgomery, Pulaski, Wythe, Smyth, Washington, Bland, Tazewell, Russell, Scott, Lee, Floyd, Carroll, and Grayson, Virginia, and run over into Ashe County, North Carolina. One locality of semi-magnetite, in the centre of the great Giles County basin, has in sight, by actual measurement, 50,000 tons of ore, which, according to Prof. Fesquet, contains 69.74 per cent. of iron and no phosphorus. In the great brown-ore belt, which passes through the counties of Montgomery, Pulaski, Wythe, Smyth, and Washington, there is an extraordinary deposit of more than a million tons. A small section of this very long vein, on Cripple Creek, in the County of Wythe, yields an ore which, analyzed by Mr. James Aumann, gave the following results: Metallic iron, - 58.15 Water, - 12 96 Alumina, - 2.32 Silica, - 1.09 Phosphorus, - none. At one point towards the western end of Red Land Mountain, in Pulaski County, New River section, I measured a body of ore in this belt which will yield, to a depth of 150 feet, over 8,000,000 tons, and the deposit extends far below the 150 feet measured at the upper part. Again, at Rich Hill, near the mouth of Reed Island Creek, these veins show extraordinary surface development, giving an ore of very great purity. At numerous places, also, in the counties of Giles, Bland, Tazewell, Russell, Scott, Wise, and Lee, these brown and red iron ores are exposed in such vast quantities as to baffle both description and measurement. That of Chestnut Flat, in Giles County, back or west of the Angel's Rest Mountain, is an easily reducible ore, blood-red when crushed, of which there are fully 300,000 tons in sight. Its analysis is as follows

Jan 1, 1880

By Robert Warner

The growing importance of screening makes an accurate measure of the quality of a sizing operation desirable. Screen efficiency is considered equal to the percentage of true undersize in the feed obtained as undersize from the screen. This method is unreliable, as it gives the same credit for removing minus 200-mesh material as for removing material just able to pass the aperature of the screen. A more accurate measure of screen efficiency is to consider only the work done on the "difficult" grains, that is, those grains of which the intermediate diameters closely approach the screen aperture.. The application of this method is given, together with the derivation of formulas and an example of their use. Is AN accurate measurement of the efficiency of a screen under a given set of operating conditions valuable? If so, what is the efficiency; of, a screen and how can it be measured? Sizing, especially of the finer sizes of material, has increased in importance in the development of flow sheets as a result of the perfecting of the rapid vibrating screens. More consideration should be given screens in the preparation of ball-mill feed, where they permit the admission of a dryer feed than, the classifier. Where possible, the introduction of a screen ahead of the primary ball-mill, and the diverting of ore below, say, 4 mm. to a secondary mill, might result in a greater overall economy because of the thicker feed and the better, adjustment of crushing media and mill operation to the reduction demanded. With the present trend back toward a combination of gravity methods and flotation, rather than flotation alone, the accurate, economical sizing possible with the new screens makes fine jigging a method to be considered. W. 0. Borcherdt1 and John Bland2 discuss the screening problem and also the value of close sizing in the concentration of some of the rare-metal ores. If a screen is to be used, it should be selected in competition with others; other things being equal, that screen which makes the cleanest oversize should be preferred. The quality of the screening and the tons

Jan 1, 1924

By H. Kobbè William

ARTHUR KNAPP, Ardmore, Pa. (communication to the Secretary*).¬On p. 2275 I find a quotation from Mr. Thompson regarding the fountains of the Baku field. I have seen a large number of these gushers or fountains. In every case where unusual amounts of sand were produced the wells caved in and shut off in a few clays and were an absolute loss Very often the formation had caved so far up as to allow the water to enter the oil strata, and not only was the well lost but the ground for many acres around the well was useless for drilling purposes because the disturbed ground had allowed the gas and oil to dissipate and the water to enter. On p. 2268, Mr. Thompson is again quoted regarding the Balakhany field. If the text is consulted further, it will be found that the oil at Balakhany is heavy only in contradistinction to the Bibi Eibat, field. The gravity of the oil at Balakhany is from 28 to 32. Also, it must be noted that the illustration is taken from the conditions in the older part of the field. This field was first chilled 40 years ago, and was a worn-out field 15 years ago. The wells which produce sand are wells in which the casings are practically gone and the formations are full of water. The sand must be bailed from these wells because the clays from the upper stratum have caved into the wells and are obstructing the passage of oil. On p. 2262 is the statement that the Russian wells cannot be pumped on account of the large amounts of free sand produced. They have never tried pumping in the Baku field to any extent. Wherever tried, it has proven a great success. If we take the author's theories as correct and wish to put them into practice, it would first be necessary to consider a few figures. Let us assume that we produce oil and sand together in the proportion in which they exist in the productive strata. It is not uncommon to have wells in the California field which are not gushers, but which, by pumping, produce 1,000 bbl. per clay the first 100 clays.

Jan 3, 1917

By W. J. Sharwood

In the cyanide process, gold and silver are dissolved from crushed ore as double alkali-metal cyanides, from which they may be precipitated by such positive metals as sodium (amalgam), aluminum, or zinc, or by electrolysis. Two extreme conditions may be noted. Some works, especially slime plants practising decantation, use a relatively large volume of solution—possibly 4 or 5 tons per ton of ore—nearly all of which may require precipitation, so that the solutions handled are of much lower value per ton than the ore. On the other hand, in some leaching plants it is possible to extract with very little solution, and to percolate some of this more than once through the charge before precipitation, so that the solution to be precipitated may be much less than half the weight of ore, and proportionally richer. Solution intended for further use need not have all its precious metal removed, but any that has to be thrown away should be impoverished as far as is economically possible. In spite of certain advantages possessed by other precipitants, zinc in some form has been almost universally used.. In some of the first attempts to utilize cyanides as gold solvents, a "piece or plate of zinc" was suggested as a precipitant, but extension of surface was early recognized as a desideratum. . Macarthur and the Forrests adopted a "metallurgical filter" of zinc shaving, turned from disks or rolled sheets. They had previously experimented on other forms of zinc, ax! Mscarthur records having tried zinc dust, which had of course been long known as a general reducing agent. It had also been known and used as a precipitant of precious metal from plating and photographic solutions, and comminuted zinc had been patented for recovering copper, etc., from ore leaches. Other inventors proposed the virtual making of zinc powder by the attrition of balls of zinc, and by similar means, during the passage of a stream of gold-bearing solution. Sulman claimed the use of zinc dust, or fume, in a special apparatus, effecting a more or less regular feed of dust and solution by means of intermittent siphons; the mixture or "emulsion" (as it is still called) rising with diminishing velocity through an inverted cone in which it

Jan 1, 1918

By Douglas A. Sloan

Who would believe that young elementary school children could understand something as complex as the mining industry? The Challenge The challenge of accomplishing this is tremendous. An examination of Canadian school children indicated that they knew very little about the world of work in general, and hardly anything about the mineral resource industry in particular. It calls to mind the story about two youngsters who decided to play house. The little girl played her role well as she went about the house doing things she had watched her mother do every day. When it was the little boy's turn, he grabbed his lunch, waved goodbye to his "wife," jumped on his bicycle and pedalled furiously down to the end of the driveway-where he stopped. The youngster explained that he saw his dad go out of the driveway each morning, but he didn't know where he went, or what he did on the job. When you stop to consider the number of families today with two working parents, you can begin to appreciate the importance of the opportunities for role identity provided by this project. The Approach The challenge of teaching the school children of Canada about the world of work and, specifically, the mining industry is the challenge which the Canadian Institute of Mining and Metallurgy met with the Curriculum Development Research project. It started when a small, dedicated group of Vancouver members met Dr. Doreen Binnington. After this meeting, Dr. Binnington, an expert in curriculum development at the University of British Columbia, set herself to develop a curriculum program for the elementary shcools which accomplishes two main goals: It uses the "Identity Approach," developed by Dr. Binnington, an expert in curriculum development at the enable students to understand and appreciate the contribution of people, in this case, working with mineral resources. It has pupils enthusiastically exploring the importance of rocks, minerals, and the mining industry in their lives [(Fig. 1)]. Evolution of the Curriculum Development Research Project When the curriculum development research project was presented to the Vancouver Branch of the Canadian Institute of

Jan 1, 1981

By John Hays Hammond

The following notes are descriptive of a country as yet in its infancy as regards the advancement made in mining operations. Its inaccessibility and other militating circumstances have retarded progress in that direction. With the completion of the railroad, now under construction, having the city of Cali as its objective point, with the concomitant civilizing and developing consequences, it is certain that the slopes of the Cordilleras will prove to be a South American Eldorado. Deposits of coal, copper, and minerals other than those of the precious metals are known to exist in quantities which, under more favorable conditions of accessibility, etc., could be profitably mined. The Government of the United States of Colombia, I think, is disposed to encourage and foster mining enterprises. Articles designed for mining are admitted free of duty; the permanency of the government is, at least, as well assured as that of Mexico (which is not noted for its immutability), and a more sincerely friendly sentitment towards Americans prevails in the United States of Colombia than in Mexico. This paper is confined to a description of the property of the Cauca company's mines, and is intended rather as a preliminary notice than as an exhaustive report. The Cauca mining district is reached by the following route: New York to Aspinwall; to Panama; to Buenaventura, a port on the west coast of the United States of Colombia, distant thirty-six hours from Panama by steamer; to Cali in the State of Cauca. The State of Cauca is bounded on the north by the Atlantic Ocean, on the northwest by the State of Panama, on the northeast by the States of Bolivar and Antioquia, on the east by Brazil and Venzuela, on the south by the Republic of Ecuador, and on the west by the Pacific. Ocean. It has a territory of 41,443 square miles, which is about one-tenth of the entire territory of the United States of Colombia. Its population, including the 50,000 savage Indians of the Caqueta (some of whom are cannibals), is nearly 450,000 souls, or about one-sixth of the population of the Colombian republic. Of these, one-fifth are whites (Spanish' South Amer-

Jan 1, 1885

By Gustav Werner, Leonard Greenburg, William B. Harris

Haulage in tunneling operations generally has been done with electric locomotives. As a rule, on short hauls the source of electricity is a storage battery mounted on the locomotive, which, of course, must be removed and recharged periodically. Where the distance from the recharging point to the tunnel face is very long, and where loads are heavy, trolley-driven locomotives are used. Diesel engines have been used in mining and tunneling operations in Europe for a number of years. The recent reports of studies in Belgium1 and by the Bureau of Mines in this country2-4 have indicated the potentialities of this form of power for haulage, mucking, bulldozing and many other underground operations. The hazards attending the use of Diesel engines in more or less closed spaces have long been known. The exhaust constituents that may create a harmful or objectionable environment are carbon monoxide, oxides of nitrogen and sulphur, carbon dioxide, aldehydes and smoke. Lack of precise information regarding the concentration of these gases and the ventilation requirements to reduce them to safe levels has to some extent suppressed their general acceptance in tunneling and mining work. Not until the work of the Bureau of Mines referred to above, and certain experience gained in the construction of the Delaware Aqueduct, ‡ has there been available the requisite information regarding the conditions under which their use may be permitted. This paper concerns itself with the successful operation of Diesel engines underground in the construction of certain parts of the Delaware Aqueduct, and describes the conditions under which Diesel engines have been found to operate with a minimum production of noxious gases. The test data reported were obtained during the operation of Diesel engines over a period of two years.* Studies by the New York State Department or Labor Exhaustive tests were made by the Division of Industrial Hygiene, of the composition of the exhaust gases given off by a Diesel engine mounted on a test block. These tests showed that certain' quantities of the gases are discharged from the exhaust. On the basis of these figures, preliminary requirements of design and control

Jan 1, 1943

Lucien Eaton, Ishpeming, Mich. (communication to the Secretary *):—I began to use water Leyner drills at the Cliffs Shaft mine at Ishpeming, Mich., over four years ago, and now have over 20 in use. The ore in this mine is hard specular hematite, and is mined by the room-and-pillar system, the rooms being driven as breast stopes. For many years only 3 1/4-in. piston drills were used in the mine, each machine ordinarily being able to drill from 15 to 25 ft. of holes in a shift. In the hardest ground, however, it was often, impossible to drill more than 2 or 3 ft. in a shift. When water Leyner drills were used the footage drilled was materially increased, especially in the hardest ground, but it was found that in very hard ground the breakage of machine parts, and especially of drill steel, was very high. At this time round steel with lugs forged on the shanks was used, and most of the breakage occurred at or near the lugs. Many experiments were made in an endeavor to overcome this breakage, and it was finally decided to do away with the lugs altogether, and use hexagonal steel. Accordingly I designed a chuck to use hexagonal steel without luge, a tappet being interposed between the hammer and the shank of the' drill steel. The design of this chuck of the proper size for the No. 18 Ingersoll-Leyner drill is shown in Fig. I. The different parts are also shown photographed in Fig. 2. A is the barrel of the chuck, which revolves inside the front head. It is made of machinery steel. B is the bushing which screws into the front end of the barrel A, and in which the drill steel fits loosely. This is turned down from a steel casting, the hexagonal hole being cast and then broached out to the proper size. It is case hardened inside. C is the tappet, which fits smoothly inside A just behind the bushing B. It is made of " N " temper Crescent tool steel and is carefully tempered. D is the tappet ring, which prevents the tappet from being pushed back too far by the

Jan 1, 1914

By Eugene A. Stephenson

The writer apologizes for presenting this very elementary analysis of one aspect of proration, but a search of the literature failed to disclose any concrete illustrations of the effect of various proration formulas upon the allowable oil produced by tracts of different sizes. Many engineers have doubtless made somewhat similar calculations and are fully acquainted with the results. The various allocation formulas that are in use are based on one or more of the following factors: (1) wide-open well potential, (2) potential through an orifice, (3) uniform well allowable, (4) acreage, (5) sand thickness, (6) bottom-hole pressure, (7) productivity index, and (8) volumetric displacement. Of these, the unrestricted potential formula, or open-flow test, and the uniform well allowable are commonly regarded by engineers as those least likely to give each producer his proportionate share of the oil or gas, as represented either by acreage or by sand thickness, or both, except when the wells are located on tracts of large size. Unless the mechanical equipment that may be used during the potential test and the method of taking the test are both specified, the net result of the potential formula is to practically force the operators to use special equipment and adopt special procedures prior to and during the potential test, so as to secure the largest possible allowables. Much ingenuity and skill have been devoted to this,problem, but the general effect is to permit excessive allowables for very small tracts, and stimulate unnecessary drilling. It is interesting to compare some of the high yields from the Wilcox horizon at Oklahoma City with each other, as an illustration of the effect of an allocation factor based solely on potential (Table 5). One of the glaring instances is a well on a ½-acre lease, which had produced, as of September 1936, at the rate of almost 3,000,000 bbl. per acre. This is at least twice as many barrels as could have been present under the property if the reservoir had consisted of a tank of oil 200 ft, deep and 56 acre in area. Numerous combinations of acreage, potential, bottom-hole pressure, sand thickness, etc., have been proposed and are in use in various fields.

Jan 1, 1937

By Horace Winchell

IT IS OFTEN interesting to look backward and review the world's progress in any line of human endeavor. Our pride is flattered by our achieve-ments and our imagination stimulated by the compari-son between our present productivity and prosperity and those of the relatively unenlightened days of our recent ancestors. We love to reflect on the progress of the last quarter of a century in the art of metallurgy, in. the production and consumption of the various metals and minerals which constitute the basis of our industrial and commercial supremacy. We dwell complacently on the figures which prove that we are the world's leader in nearly all departments of mining and that our production of necessary minerals over-shadows that of other countries. We recall the days when it was considered the proper thing, if not indeed indispensable, to go abroad for the rounding out of a mining engineer's education. We had no mining schools equal to those of Germany. Our schools of technology were elementary and their equipment limited. RISE OF AMERICAN MINING SCHOOLS Now we point with true American pride to institutions which, are unsurpassed in all the world in their standard of efficiency. We know full well that the American engineer is in demand in many foreign parts and when we read recent scientific treatises published abroad we are amazed to find them unfamiliar with many of the more advanced ideas which have here already come to be an everyday part of our professional knowledge and equipment. Blessed with a country of unrivalled natural resources, dwelling in a latitude whose climate is most conducive to enterprise, peopled with races of inventive and organizing genius with equality of individual opportunity, our industries have grown and expanded until our output has reached staggering proportions and the draft upon our mineral reserves is appalling. Coupled with this development has arisen a demand for engineers which has brought into our schools of technical science larger and larger numbers of young men whose imagination has been stimulated by the success of their predecessors who happened to be contemporary elements in the recent industrial expansion and prosperity.

Jan 1, 1923

By Eugene A. Stephenson

In most instances the fluids produced from underground reservoirs have been described as they appear at the surface, and usually it has not been necessary to distinguish between surface and reservoir phases. More recently it has become imperative to recognize the fact that changes in phase may occur between the reservoir and the receiving unit. The simple terminology of "wet" and "dry" gases and "crude petroleum oil" served our needs fairly well in the shallow, low-temperature and low-pressure fields. It has been left to the legislatures, regulatory commissions, and courts to decide whether a field is or was a gas field, an oil field, or both. This they have done by direct definition and also by implication. For example, in Texas:' (d) The term "gas well" is any well (a) which produces natural gas not associated or blended with crude petroleum oil at the time of production, or (b) which produces more than one hundred thousand (100,000) cubic feet of natural gas to each barrel of crude petroleum oil from the same producing horizon, or (c) which produces natural gas from a formation or producing horizon productive of gas only encountered in a well bore through which crude petroleum oil is also produced through the inside of another string of casing. (e) The term "oil well" is any well which produces one (1) barrel or more of crude petroleum oil to each one hundred thousand (100,000) cubic feet of natural gas. In the state of Louisiana, the same general result is achieved largely by the following paragraph :* Wells producing both oil and gas shall not waste or blow into the air an amount of gas of more value at three cents per thousand cubic feet, than the market value of the oil recovered. The Commissioner of Conservation shall allow a reasonable time to determine the status of any well. This means that for wells making both oil and gas, if n represents the price of oil in dollars, and x the allowable gas waste expressed in M cu. ft. Per day,

Jan 1, 1938

All the TECHNICAL PUBLICATIONS and CONTRIBUTIONS published in 1938 are available at Institute headquarters, unless otherwise noted. They are also on file in many public, university and technical libraries and, when so indicated in the list, may be found in the TRANSACTIONS. TECHNICAL PUBLICATIONS in Classes A-Metal A-Lining, B-Milling and Concen-tration, H-Industrial Minerals, and I-Mining Geology are distributed in MINING TECHNOLOGY, which is issued every other month. Technical Publications in Classes C-Iron and Steel Division, D-Nonferrous Metallurgy and E-Institute of Metals Division are distributed in METALS TECHNOLOGY, which is issued twice quarterly. TECHNICAL PUBLICATIONS ill Class G-Petroleum Division are distributed in PETRO-LEUM TECHNOLOGY, which is issued quarterly. TECHNICAL PUBLICATIONS in Classes F-Coal Division, .l-Mineral Industry Education Division, K-Mining Administra-tion, and L-Geophysical Methods of Exploration are issued as separate pamphlets. All Institute member is entitled to one copy of any TECHNICAL PUBLICATION or CON-TRIBUTION. Copies of TECHNICAL PUBLICATIONS listed have been mailed to members of the Institute according to their registration by classes. CONTRIBUTIONS and other TECHNICAL PUBLICATIONS will he sent upon request. A member may purchase an additional copy of a TECHNICAL PUBLICATION or a CONTRIBUTION at one cent. a page; in minimum charge, 256. If the TECHNICAL PUBLICATION has been published in METALS TECHNOLOGY, MINING TECHNOLOGY or PETROLEUM TECHNOLOGY, the number of either magazine containing it will be supplied at the sae cent a page (minimum charge, 25¢) rate for the particular TECHNICAL PUBLICATION requested. Nonmembers may purchase any CONTRIBUTION or a TECHNICAL PUBLICATION Of the F, J, K, or L classes at the same rate, butt the nonmember price per copy for METALS TECHNOLOGY, MINING TECHNOLOGY or PETROLEUM TECHNOLOGY is $1. TECHNICAL PUBLICATIONS (Separate pamphlet form), $2 per annum; Canadian and foreign postage 50 cents extra. METALS TECHNOLOGY, $7 per annum; Canadian and foreign postage 50 cents extra (Iron and Steel Division and Institute of Metals Division ferrous and nonferrous papers). MINING TECHNOLOGY, $6 per annum; Canadian and foreign postage 50 cents extra (metal mining, milling and concentration, Industrial Minerals Division, and mining geology papers). PETROLEUM TECHNOLOGY, $4 per annum; Canadian and foreign postage 50 cents extra.

Jan 1, 1938

By R. B. Moffitt

INTRODUCTION In recent times the continuing depletion of high grade mineral deposits and the massive increase in raw material consumption have forced the metal mining industry to exploit ore bodies of lower and lower grades. To obtain a satisfactory financial return from these deposits, there has been the concurrent and evident trend towards increasing the size of operations to obtain benefits from the economies of scale. The evaluation, planning, and design of these large scale open-pit operations, so as to yield the maximum possible return on investment, is an extremely complex, iterative procedure. With profit margins trimmed, "small" errors can become much more significant and with exploration costs spiralling, accurate and rapid evaluation is essential. It demands a sophistication and precision in the evaluation process unheard of ten years ago. What follows attempts to describe the need to thoroughly plan the overall evaluation programme such that duplication of effort is avoided and all relevant information is systematically recorded from the outset of exploration. The final section of the paper takes a realistic case study to illustrate the significance of pit slope angles on the design of the final pit and the economics of the total project. THE EVALUATION PROGRAMME The team, (for a team effort it must be), that is charged with the responsibility of conducting the evaluation exercise, has the difficult task of placing values on a multitude of independent and inter-related variables. Each variable has some economic significance; the degree of significance varying according to the metal sought, the environment in which it occurs, the vagaries of the market place, to name but a few of the problems facing the project team. From this maze of variables, the team must identify those that have the most critical influence on the overall economics of the proposed venture. Investigations must then be set in motion to quantify these controlling factors more precisely. It is important to recognize that such investigations form part of the evaluation programme and require monitoring for both timing and cost as the whole exercise of evaluating the project continues. To add to the difficulties, the economic significance of any particular variable may change during the course of the programme.

Jan 1, 1972

By Thomas A. Hendricks

The object of this paper is to give a brief description of the coals in the different districts of Arkansas and Oklahoma, their present commercial classification, and the need for a scientific classification that shall be more nearly in accord with their physical and chemical properties and shall place them in their proper position in a general scheme of classification. The paper is based on two seasons of field work in the Oklahoma coal field in 1930 and 1931 and on several weeks spent in visiting most of the operating mines in Arkansas in the same years. Most of the productive districts of the Arkansas-Oklahoma coal field lie in an east-west trending belt immediately north of the Ouachita Mountains, but the northwestern districts in Oklahoma trend northward toward Kansas. With the exception of the Muskogee district, where very little coal has been mined, the coal beds of the last-mentioned districts are all younger than those of the districts in the east-west trending belt. Description of the Coal by Districts Lehigh District, Oklahoma (5).1—In the Lehigh district mining has been extensive, but only three or four mines are operating at the present time. Two coal beds of workable thickness, Atoka and Lehigh, are known in this field. The greater part of the mining has been in the Lehigh, or younger bed, and all analyses available for the field have been of that coal. The Lehigh coal is very tough and blocky, the moisture and ash contents are fairly high, 6.5 and 10.7 per cent respectively, the volatile content is 39.5 per cent, fixed carbon 43.4 per cent, B.t.u. value 11,525, and the fuel ratio 1.1 (average 15 analyses). So far as the writer has been able to ascertain, laboratory attempts to coke this coal have been unsuccessful and no attempt has been made to produce coke commercially. Tulsa District, Oklahoma (l).—All commercial mining in the Tulsa district has been by stripping from the Dawson bed, and production has never been very great. The coal is blocky, contains 6.5 per cent moisture, 36.8 per cent volatile matter, 48.4 per cent fixed carbon, and 8.3 per cent

Jan 1, 1932

By L. W. Kemph, K. R. VanHorn

During the recent development of aluminum alloys for free-cutting screw-machine rod, it became desirable to know something of the solubility of lead and bismuth in liquid aluminum and in some aluminum alloys. The literature is not particularly helpful in supplying this information. These portions, therefore, of the constitutional relationships of aluminum-bismuth and aluminum-lead alloys were investigated by thermal analysis and by chemical analysis of samples taken from aluminum-rich melts in equilibrium with precipitated lead or bismuth. The solubility of lead and bismuth in some liquid aluminum-copper alloys was also investigated. Some consideration was also given to the solubility of these elements in solid aluminum. Among the earliest investigators of the aluminum-lead and alunlinum-bismuth systems was Wright,' who reported that melts of aluminum and lead formed two layers indicating limited liquid solubility. Under his conditions, the aluminum-rich layer was reported to contain 1.91 per cent Pb and the lead-rich layer, 0.07 per cent Al. Subsequently, Pecheau2 found that in aluminum-rich alloy melts with more than 10 per cent Pb three layers were distinguishable. He reported that the middle layer contained from 3 to 10 per cent Pb. He also found that the melting point of aluminum appeared to be lowered slightly by the addition of lead. Gwyer3 investigated these alloys and found evidence of a slight lowering of the freezing point of aluminum by the addition of either lead or bismuth. He found no evidence of solid solubility in either case and made no attempt to determine the liquidus curves. Hansen and Blumen-tha14 reported that the addition of lead distinctly lowered the solidification point of aluminum. They also found that bismuth lowered the melting point of aluminum. Guillet5 reported almost complete mutual immiscibility for the aluminum-bismuth alloys in the liquid state. Bohner6 examined the effect of various concentrations of lead and bismuth on the electrical conductivity of aluminum. He found decreases in conductivity on annealing at 500' C. as compared with the conductivity of the same alloys on annealing at 300' C.

Jan 1, 1939

By S. C. Carapella, E. A. Peretti

DURING a literature survey of the indium-zinc phase diagram, controversial reports on the composition of the eutectic point were encountered. The value reported in the investigation of Wilson and Perettil and in a later investigation by Valen-tiner' was 4.0 wt pct zinc. The most recent work recorded on this system consisted of an exhaustive survey of alloys by Rhines and Grobe8 in which they indicate a value of 2.8 wt pct zinc for the eutectic composition. To clarify this aspect of the diagram, a series of alloys were prepared by melting the respective constituents in a glass test tube under a covering of mineral oil and slowly cooling the melt in a furnace. The zinc used was Baker's C.P. and had the following analysis: insoluble in H2SO4—0.0l pct; pb—0.001 pct; Fe-—0.001 pct. The indium, which was supplied by the Indium Corporation of America, had a purity of 99.9'7 pet with the following impurities: Cu—0.002 pct; Pb—0.006 pct; Sn—0.01 pct; Zn—0.01 pct. The alloys were prepared for metal-lographic examination using a technique already reported' and a new value of 2.0 ± 0.1 wt pct zinc was observed. An alloy containing 2.00 wt pct zinc was also made by melting the constituents under a vacuum. In both of these methods of alloy preparation the losses can be kept extremely small. Again, the characteristic eutectic structure was obtained, assuring confidence in this value. The accompanying micrographs are presented in support of this point. Fig. la represents an alloy containing 4.00 wt pet zinc, and reveals excess zinc particles, which precludes the value of both Wilson and Peretti, and Valentiner. Fig. lb, gives the structure of an alloy containing 2.2 wt pct zinc, also showing the presence of excess zinc. Fig. lc is a micrograph of a typical structure of the eutectic observed in several sections of the 2.0 wt pct alloy. In the 1.8 pet zinc alloy, fig. id, the definite presence of the primary indium can be noted. From these re-

Jan 1, 1951

By D. H. Newland

Certain observations from the field and laboratory suggest the need for recasting some of our ideas about gypsum as a rock-forming mineral and in relation to supplies for industrial use. Until about 25 years ago, the use of gypsum was confined almost entirely to agriculture. During the past quarter century, though, its usefulness has been greatly developed, particularly in the building trades, which now absorb most of the gypsum produced. In 1919, according to the U. S. Geological Survey, the output of crude gypsum was 2,240,163 tons, a gain of 912 per cent. in 25 years. About one-half of this production was mined in New York, Ohio, and Michigan, where the proved supplies can hardly be regarded as over-large when viewed in relation to the rapid expansion of industrial requirements. The occurrence of gypsum in the United States is treated by R. W. Stone and others.' The deposits of Canada are described by L. H. Cole. Several states, including Kansas, Oklahoma, Iowa, Michigan,and New York, have made special surveys of their gypsum deposits, but the reports, as a rule, refer to conditions as they existed from 15 to 20 years ago. Association of Gypsum and Anhydrite The two calcium sulfate compounds, gypsum (CaSO4.2H2O) and anhydrite (CaS04), are the more stable forms of a series which includes at least two other members, so-called half-hydrate (CaSO4.1/2H20) and soluble anhydrite (CaS04). Each of the latter readily takes up water to recrystallize as gypsum and consequently is incapable of existence under ordinary geological conditions; also each can be prepared from gypsum by the application of heat within certain temperatures, the process on which is based the manufacture of commercial plasters. If the temperature limitations are not observed, the result of the calcination process will be insoluble anhydrite which, compared with the soluble form, takes up water very slowly so as to be of no practical use, although actually it is soluble and in time is convertible into gypsum like the other forms.

Jan 1, 1922

By J. Earl Frazier, Howard A. Meyerhoff

IT is not known when silica sand was first noticed along the north coast of Puerto Rico, but the first mention of its occurrence was made in 1922, by N. L. Britton,1 who described its presence in isolated patches extending from Loiza westward beyond Manati. Further observations were made in 1925 and 1926 by Meyerhoff,2 who extended the known occurrences still farther westward to the low hill belt in the Quebradillas limestone immediately south of Hatillo. The extraordinary purity of the sands, which in most localities exhibit no contamination from the nonsiliceous materials surrounding them, was quickly appreciated, and the feasibility of utilizing them for the manufacture of glass was investigated, initially by the Committee on Mineral Resources3 and later (1936) by the Puerto Rico Reconstruction Administration and by H. C. Ray, mining engineer of the Insular Bureau of Mines. In 1934 samples submitted to the Hazel Atlas Glass Co., of Washington, Pennsylvania, were reported to have the composition as shown in the table on column two. Appreciation of the quality of the sand prompted geological and quantitative studies of the deposits, as well as commercial investigations to determine the feasibility of utilizing it locally or on the mainland for the manufacture of glass containers. [ ] DISTRIBUTION OF THE SANDS The quartz sands consistently lie within the outcrop area of the Quebradillas limestone, the youngest of the Miocene formations in the Tertiary coastal plain that fringes the northern coast of the Island. Many of the deposits are closely associated with limestone outcrops, but some appear to be embedded in lagoonal sediments at some distance from rock exposures, and at least one deposit, near Dorado, has been reworked by waves and littoral currents. With this single known exception, the deposits consist of irregular, patternless patches of white sand, which have sharply defined contacts with the surrounding material. Although patches of sand are present in a 90-km. belt that is not more than 5 km. wide, extending from Loiza to Hatillo, they attain maximum size, purity and number in the north central coastal area between Dorado and Barceloneta. Fifty separate deposits have been mapped in

Jan 1, 1945

By L. O. Howard

The practice of using acid-lined converters at the plant of the Old Dominion, Copper Mining & Smelting Co. was discontinued early in January, 1913, and replaced by basic-lined converters. The new equipment consists of one electrically operated 12-ft. upright converter stand and two basic-lined shells for same. These shells are provided with twenty-four 1 1/4-in. tuyeres. The mouths are 5 ft. in diameter. Owing to the fact that there is no bedding system or other large storage capacity between the mine and the smelter, the furnaces must handle as fast as produced ore and concentrates, which may vary considerably from day to day, both in tonnage and copper content. Consequently the converter is often crowded to its utmost capacity by the frequent fluctuations in the daily matte supply. From the foregoing, it will be seen that in no way can the 'converter be favored by running light charges or by transferring to it from other stands in operation. Neither can it regularly be allowed to cool between blows, and only occasionally can it be run at as low a temperature as might be wished. No copper precipitate or other foreign material high in copper is available to help out the tonnage. Repairs and alterations or the removal of defective tuyeres must wait until such time as a slight falling off in.the matte supply allows the converting operations to ease up. These variable conditions all combine to interfere with the systematic operating of the converter. The first 12-ft. shell was blown in on Jan. 6, 1913, and ran until June 27, 1913, when it was removed to patch the brick. A record of operations covering this period follows: Shell No. 1. First Campaign, Jan. 6,to June 27, 1913 Commenced blowing............................Jan. 6, 1913. Taken off stand for patching.....................June 27, 1913. Total blowing time..........................2,689 hr. 40 min. Total number of, blows made.............................. 664 Average time of blow............................ 4 hr. 3 min. Tons matte charged.................................. 18,157 Average copper content of matte................ 43.9 per cent. Average time blowing one ton. copper................ 22.5 min. Total copper made............................... 7,250 tons

Jan 1, 1915