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By J. W. Halley

COPPER has frequently been recommended as an alloying element for steel and the precipitation-hardening of steels containing from 1 to 2 per cent copper has been studied by a number of investigators. The straight copper steels, however, have not been used extensively and little advantage has been taken of the precipitation-hardening of complex steels containing appreciable amounts of copper. It is diffi-cult to produce a satisfactory surface on the straight copper steels and undoubtedly this has discouraged their use. During recent years a number of steels containing enough copper to make them susceptible to precipitation-hardening have been put on the market. These steels belong to the group usually referred to as "low-alloy high-tensile" steels. They were designed for use in the "hot-rolled" condition; transportation equipment and large structures that cannot be readily heat-treated have been their chief application. Little emphasis has been placed on the possibility of strengthening those containing substantial amounts of copper by precipitation-hardening. The present investigation was undertaken to determine the precipitation-hardening characteristic of one of the "low-alloy steels."

Jan 1, 1940

By Sylvain J. Pirson

The main value of earth magnetic measurements, outside of certain mining problems, resides in the study of deeply buried tectonic phenomena related to regional and local geology. Magnetic surveys are a necessary complement of gravimetric measurements, especially of pendulum surveys. To date, magnetometer prospecting has been used chiefly in the study of sedimentary basins where petroleum structures are associated with the uplifted basement rocks. There are, in the literature, innumerable articles dealing with such surveys as applied to oil geology but few treat of broad geological features related to regional magnetic disturbances of the earth field. An important piece of coordination work has been made by Jean Jungl for the magnetic and gravimetric measurements made in France and their geologic significance. A similar attempt at correlation of the known geology with the anomalies of the vertical component of the earth magnetic field has been made for the United States by George B. Somers2. Taking the magnetic vector as a whole, W. P. Jenny3 made a coordination of magnetism and geology for the main producing oil states of the United States. A more detailed study along the same lines is published by A. Van Weelden4 for southern Oklahoma and northern Texas; in this work magnetic and gravimetric measurements taken at stations as close as one mile apart are compiled and compared to the regional geology of the Ouachita-Amarillo uplifted area. From the literature mentioned, it is evident that reliable interpretation of magnetic' anomalies can be arrived at only when the magnetic stations are numerous and cover the area in a close net of measurements, therefore the works of Somers and Jenny, based on sparsely distributed Government measurements, can be regarded only as preliminary programs indicating lines along which further work should be done, whereas the coordination made by Van Weelden is an example of the contribution to the knowledge of regional geology that can be arrived at by the use of applied geophysics. With the hope that further systematic magnetic measurements will be carried on to solve regional and local geological problems, the author

Jan 1, 1940

By S. F. Ravitz

IN his excellent book on the Principles of Flotation, Wark' makes the following significant statement concerning the theory of flotation: Two questions of first-rate importance must be considered . . . First, it must be decided whether the sulfide minerals require a collector in order that they may float, or whether as has been claimed, they possess an inherent floatability and need no collector. Second, it must be decided whether the xanthate type of collector can react with or be adsorbed by the unchanged sulfide minerals themselves, or whether, as many claim, reaction with the collector is dependent upon initial oxidation of the mineral surface. In the theory of flotation there are no two questions of greater importance than these. Ravitz and Porter' presented evidence that galena can be floated without a collector, and even without any reagent, provided oxidation products are thoroughly removed from its surface. They found also that thoroughly cleaned galena floated faster when xanthate was used than when a frother alone or no reagent was used, and that, without a collector, the recovery decreased gradually upon exposure of the mineral to air. Their work, however, has met with considerable criticism. I(127).3-6 This paper is presented to answer the objections that have been raised, and to present additional data that confirm their results. EXPERIMENTAL PROCEDURE The apparatus used to provide oxygen-free conditions for flotation has been described in detail by Ravitz and Porter. An atmosphere of purified nitrogen was maintained within the apparatus; all water and solutions used were freed of dissolved air, and could be transferred where desired by the use of nitrogen pressure; nitrogen was used as the gaseous medium for flotation. The flotation cell was essentially a glass cylinder 15 cm. long and 4.6 cm. in diameter. Near the bottom was sealed a fritted glass filter, which broke up the gas into small bubbles, and 6 cm. above this filter was a side arm through which the froth overflowed. The pulp was agitated by a glass impeller, which entered the cell through a mercury seal. For each test 17 grams of galena and 75 ml. of water were placed in the cell, after which the speed of the impeller and the rate of gas flow were adjusted. Water was added gradually during the test to keep the froth level at the proper height. The mineral was prepared and cleaned in the following manner. Exceptionally pure galena was crushed by hand on a clean bucking board, screened to - 150+ 200 mesh, and deslimed on a zoo-mesh sieve with a fine spray of water. It was then boiled on a hot plate for a number of hours with several changes of the desired cleaning solution, after which both the solution and the mineral were placed in the "mineral flask" of the apparatus. The cleaning solution was drained off, and the mineral was boiled with oxygen-free water

Jan 1, 1940

Masjid-i-Su1aiman.—There have been no new developments in the Masjid-i-Sulaiman field during the year. Drilling, deepcning and acidizing operations for maintenance of production havc continued normally. Reservoir conditions have been unchanged, the rate of fall of dome prcssure remaining very low—at about 0.4 lb. per sq. in. per million tons net production. Drilling on the Lali structure northwest of Masjid-i-Sulaiman has continued but oil has not been encountered in commercial quantities. Haft Kel.—The progressive drilling program extending the production capacity of the Haft Kel field was completed carly in the year and the field is now on a routine maintenance basis. Drilling has continued on the white-oil springs structurc northwest of Haft Kel. Naft-i-Shah.—No developments of interest have occurred in Naft-i-Shah field. Offtake is for local markets only. A further large produeer was completed during the year. Gach Saran.—By the end of 1939, work on plant and pipe lines to put, the field on a production basis was approaching completion. Two substantial producers were also drilled in the initial production area. Pazanun and Agha Jari.—No further drilling was carried out on the Pazanun structure during the year, gas only having been obtained to depths exceeding 8000 ft. On the adjacent Agha Jari structure, however, a second satisfactory oil producer was completed.

Jan 1, 1940

The separate outputs of Burma and India in 1937 were 274,664,365 gal. valued at £4,474,147 and 75,657,857 gal. valued at £1,030,591, respectively. The corresponding figures for the year 1938 were 263,823,-265 gal. valued at £3,766,810 and 87,082,371 gal. valued at £1,234,563, respectively, which is a slight increase in total quantities but a fall in value for the combined outputs of Burma and India. The appreciable increase from India in 1938 is due to an increase of over 11 million gallons from Attock and a little from Digboi, while the decrease from Burma is due to a fall of nearly 9 million gallons from Yenangyaung, over 3 million gallons from Yenangyat (and Lanywa) and half a million gallons from Minbu (Table 1). The 'amount' of gasoline produced from natural gas during the year 1938 was 10,587,291 gal. in Burma and 496,163 gal. in the Punjab.

Jan 1, 1940

By Kendall F. Born

Production of crude oil in Tennessee during 1939 was slightly more than 51,000 bbl., an increase of about 10,000 bbl. over 1938. The product,ion by counties and by fields is shown in Table 1. The increased production has rcsulted from continued activity in the Upper Cumberland district, especially in Clay County, where approximately 37,000 bbl. were marketed off the lease. This figure includes a single well in the old Tinsleys Bottom pool on the Clay-Jackson County line, although the well is in Jackson County. The "Mississippi lime" produced 10,811 bbl. in Scott and Morgan Counties, a decrease of 2568 bbl. from the 1938 production. Production during the year from some half-dozen scattered wells in eastern Clay, Pickctt, and Fentress Counties, on which there are no accurate figures, is estimated at 1000 barrels.

Jan 1, 1940

By B. H. Sage

ATTEMPTS have been made to predict the volumetric and phase behavior of naturally occurring hydrocarbon mix-tures1-5 but these methods have not been extended to the higher pressures and tem-peratures that are currently encountered in some producing formations. Furthermore, the methods of prediction at present avail-able have not been tested in a sufficient number of cases to ensure their applica-bility to all naturally occurring hydrocar-bon mixtures, even at the lower pressures and temperatures. For these reasons the behavior of a number of hydrocarbon mix-tures from a field in which the subsurface pressures are above 4500 lb. per sq. in.? and the temperatures are in the neighbor-hood of 250°F. was investigated.

Jan 1, 1940

By Harlan Walker

ROCK-DRILL steel has an important bearing on costs in many mining operations, both directly and indirectly. Direct factors include such items as shop expense, steel consumed per ton of ore produced, cost of distribution and the dust hazard. The latter, although no specific amount may be assigned to it, is an ever-present problem, and is receiving increased attention as the science of mining progresses. Indirectly drill-steel performance affects consumption of compressed air, mainte-nance of drills and drilling speed. The latter, in turn, increases or retards the tempo of mining and development. These factors, while not all inclusive, are preponderant in their importance. Thus it is evident that in an extensive operation drill-steel expense may run to many thousands of dollars and that thoughtful research leading toward more efficient practice is warranted.

Jan 1, 1940

By O. B. Hopkins

Essentially all production for Peru came from the three established fields in coastal northwestern Peru (Fig. 1). These fields are known as La Brea-Parinas, Lobitos, and Zorritos, in order of importance. Together they produced 13,496,880 bbl., as compared with 15,838,605 bbl. in 1938. Zorritos Field.—Of the total production shown on Table 1, the Zorritos field was responsible for a relatively negligible amount estimated at 40,000 bbl. This small field, which is over 50 years old, was purchased by the Peruvian Government in the spring of 1939 from the Piaggio interests. The Government operated this field along with its near-by National Reserve areas, largely under supervision of Department of Mines officials, and the total production rate for both old and newa-areas was estimated to have increased by Oct. 1 to 166 bbl. per day. as compared with the 1938 average of 110 bbl. per day. Construction is said to have begun on a refinery that is to have a capacity of 1000 bbl. per day and is to include a gasoline-extraction plant, and on a pipe line to bring fresh water 20 miles from the Tumbes River. Lobitos Fields.—The Lobitos fields, some 70 miles south of Zorritos, produced approximately 2,650,000 bbl., or almost the same amount a* in 1938. La Brea-Parinas.—The International's La Brea-Parinas property, immediately south of the Lobitos property, produced 10,806,880 bbl., or 80 per cent of Peru's production. During the year 73 wells were drilled on the Estate, mostly in the semiproved area: 44 by rotary, 13 by cable and 16 by star rigs, as compared with 34 by rotary, 11 by cable and 20 by star in 1938. The most important of the several semiexploratory wells sunk was No. 3075, which late in December was brought in at a depth of 4500 ft. with an initial production of 1500 bbl. per day, based on

Jan 1, 1940

By Sherwin Kelly

The prime objective of geophysical exploration is to promote the economical and rapid dis-covery of mineral or oil deposits of commercial value. To a few this concept as applied in min-ing may signify the direct discovery of ore-bodies, but to the geophysical engineer this latter Idea is one of the most insidious and detrimental misapprehensions which he has to combat. The destruction of this annoying obstacle to the progress of geophysical exploration reveals the kernel of truth behind it, that the exploration geophysicist has for the better part of two decades been concerned primarily with the discovery of mineral formations favorable to the occur-rence of commercial ore. There is a very real distinction here, since geophysical methods are capable of discovering certain mineral formations such as sulphide bodies or quartz veins, but are totally incompetent to predict whether or not they constitute ore; that is. whether or not they contain minerals of economic value in the amounts requisite to repay extraction. The art of geophysical exploration is now, however, rapidly outgrowing these early limita-tions. The rate of this growth will in large measure depend on the recognition by the mining industry of the fact that geophysics can play a role far wider and more important than it usual-ly does now, in guiding the future exploration and development of mineral deposits. It is my own firm conviction that as time marches on we will see the methods of applied geophysics turned more and more to the delineation of both minor and major structural features. The outlining of such features having a bearing on the probable loci of mineral deposition will be of inestimable value in guiding the development of a mining district. It is in this field that there will In-evitably occur a meeting and overlapping of the activities of the exploration geophysicists and

Jan 1, 1940

By John McDonald

THIS report is a continuation of an earlier one with a similar title,1 to which the reader is referred for such details of procedure as do not appear here. A brief summary will be given of the objects and methods of the research at this time. It was pointed out in the previous paper that properties of magnesium alloys, as re-ported by different workers, often differ. This was thought to be due to differences in the preparation of the specimens tested. The ideal way to compare alloys would be to prepare each of them in so many ways that reasonable assurance would exist that the best properties of each alloy had been developed. The alloys would then be com-pared on the basis of these properties. The treatment actually given the alloys of these studies is necessarily a compromise with completeness. Nevertheless, enough treatments have been given so that a con-siderable degree of assurance exists that the properties obtained are representative of the alloy as such, and not merely of the manner in which it was worked and heat-treated.

Jan 1, 1940

By Roy A. Hardy

THE Getchell mine is a comparatively recent discovery in the old Potosi mining district, Humboldt County, Nevada, a district organized in the seventies and eighties, in which some prospecting was done in several metamorphic zones along a monzonite-sedimentary contact. The district had no production in the early days and no further work was done until the same metamorphic zones were prospected for tungsten (scheelite) in 1917 and 1918, when a few small lots were shipped. It again lay dormant until 1934, when prospectors investigated a large siliceous escarpment at one end of the old district where outcroppings were a prominent feature of the topography. Undoubtedly, during the early prospecting of the district, the outcroppings had been investigated for mineral, probably by panning, with negligible results because the gold later found is invisible in the concentrate and is refractory. A fire assay revealed the presence of sufficient gold to warrant development work. The outcroppings were easily prospected by short tunnels having their portals in the siliceous material on the hanging-wall side, with a maximum distance to crosscut to the footwall of 135 ft., or a distance at right angle to dip of 60 to 90 ft. Development work, reaching a depth of over 600 ft. on the dip of the vein, was done by means of various crosscut tunnels, winzes and laterals. A churn-drill hole was also sunk, which intersected the vein at a depth of 1100 ft. on the dip. Sufficient development work of this character was completed by 1937 to justify the erection of a reduction plant to roast the sulphide ore and cyanide the calcine, and to treat the oxidized ore by straight cyanidation, to make a doré bullion for shipment to the mint. The erection of the plant was started that year and finished early in 1938, with a combined capacity of about 800 tons per day. It has operated continuously since erection and recently was enlarged to handle 1000 tons per day. The vein dips with the slope of the mountain, and by stripping the hanging wall the ore may be mined by power shovel for several hundred feet below the outcrop. Thereafter underground methods will be necessary.

Jan 1, 1940

[E. O'C. Acker '86 Jinzoc Adachi ‘88 *Truman H. Aldrich '78 Walter H. Aldridge '89 Anson W. Allen ‘87 *John H. Allen '84 William R. Appleby '90 *W. Lawrence Austin '82 *W. SAyres ‘73 David Baker '86 *John Henry Banks .83 Henry C.Banon '90 Alonzo F.. Bardwell '89 Walter A. Barrows ‘90]

Jan 1, 1940

By H. H. Uhlig

Soon after general use of stainless steels began, it was observed in practice that certain combinations of factors tended to induce corrosion by pitting. For most applications this was a serious drawback, not SO much because the structural properties of the metal were impaired but because of the rapidity with which heavy sections of the alloys were penetrated by small elongated pits. These pits seemed to initiate readily in oxidizing metal salt solutions like ferric chloride and in chloride solutions like sea water. It was observed that in sea water pitting was more frequent in stagnant or polluted waters than in highly aerated, moving waters. The steels in these chloride solutions were observed to be sensitive to long contact with material such as sand grains or attached barnacles. At points of attachment or contact it was not uncommon to discover initiation of corrosion. Pits once begun at contact faces were observed to grow rapidly, usually elongating phenomenally in the direction of gravity until the metal was perforated. Hydrochloric acid and other nonoxidizing acids, on the other hand, were observed to corrode stainless steels generally; the weight losses often were higher, but the penetration less than for the pitting type of corrosion. The causes of pitting, a type of corrosion recognized as characteristic not only of stainless steels but of many additional metals and alloys, are important in corrosion studies. A possible explanation bears practical significance, for once it is known why pits begin where they do and continue to grow after initiation, intelligent direction can be given to diminishing corrosion. This can be done either by some alteration in the composition and treatment or' the alloy or by some alteration in the environment. It appears foremost in importance to discover the nature of pit foci, for if initiation of pits can be discouraged their growth will be no longer a factor to be considered. In a multi-component alloy containing many impurities normal to production of such an alloy, each of which may play a part in pitting, and whose corrosion resistance is sensitive to heat-

Jan 1, 1940

By Henry H. Logan

THE purpose of mine-hoist safety controllers is to prevent hoists from being operated at speeds above those considered safe and expedient, to ensure proper acceleration and retardation near the ends of travel, and to prevent overwinding. In other words, they are to safeguard the normal speeds and movements of the hoisting drums and cages. The object of this paper is to explain the fundamental principles of hoist controllers, and to aid in their selection, installation, and maintenance. There have been many designs of mechanical hoist controllers, the basic elements of which as ultimately developed consisted of a flyball governor and another movable member supported by a frame and arranged to move in a vertical, horizontal, or rotary direction, depending upon the particular design, the whole mechanism arranged to be driven in synchronism with the hoist drum. In case of overspeeding, inadequate retardation, or overwinding, a pawl or catch controlled by the governor would engage teeth or dogs on the moving member, which through mechanical connections would cut off the power and set the brakes. Since in strictly mechanical hoist controllers valuable time was lost while the various mechanical movements took place, an important development was the invention of controllers partly mechanical and partly electrical. This type of controller has a governor and movable cams to be driven in synchronism with the hoist drum, the governor representing the hoist speeds and the cams profiled to form a pattern for retardation, representing the travel of the cages in the shaft. This type is also provided with an overspeed switch and usually with a pair of selective-limit switches, one for the top limit and the other for the bottom. In overspeeding or failure to retard in accordance with the profile of the cam, the overspeed switch will be opened, or if the top or bottom limit is overrun one of the limit switches will be opened, breaking the retaining circuit of a contactor or magnetic latch, causing the power to be cut off and the brakes applied. When the speed falls to the predetermined safe speed, the overspeed switch closes, and a hoist equipped with power-operated brakes controlled in emergency by a solenoid-operated valve can be restarted immediately by simply moving the master control lever to the "off" position and then applying power-unless brake interlocks are used, in which case the brake lever or levers must also be brought to the "applied" position, after which the hoist can be restarted in the usual way. When hand-reset weights instead of solenoid-operated mechanism are arranged to set the brakes for emergency, it is necessary to reset the weights manually, besides bringing the master control lever to the "off" position before the hoist can be restarted. Should a final limit be slightly overrun, and a stop made with a limit switch held open by a cam, it is necessary for the hoistman to use a "backing-out" switch which short-circuits the overrun limit switch, reestablishing the hoist-control circuit, and simultaneously opening the

Jan 1, 1940

Jan 1, 1940

By J. W. Dougherty, J. M. Douglas

THE Hollinger gold mine is in the Porcupine mining division, District of Cochrane, in the northern part of the Province of Ontario. The adjacent town of Timmins, with a population of 25,119, lies 490 miles by railway north of the city of Toronto. GEOLOGY The property is situated on the northwest limb of a major syncline, which pitches northeast at approximately 50°. The principal rocks of the Hollinger area are of pre-Cambrian age and consist of altered, schistose, Keewatin lava flows intruded by stocks of schistose, quartzfeldspar porphyry generally assigned to the Algoman period. The structure of the Keewatin series is extremely complex as a result of close folding and some faulting. The schistosity, trending north 70° east and dipping steeply to the southeast, is most highly developed along a subsidiary anticline in which the major porphyry bodies occur. The ore bodies, which exhibit three principal structures, consist of quartz veins and associated pyritized wall rock. Some lodes are composed of en echelon veins, others exhibit a main quartz body with branching stringers and a third consists of a single definite lead. Gold, in a coarse visible form, may be confined to quartz in some ore bodies but in others it is finely divided and is found not only in quartz but also associated with pyrite in the adjacent wall rock. In many veins the distribution of gold is such that there are several ore sections, separated by areas of low-grade material, in the same vein although its physical appearance remains unchanged. The veins form a very complex pattern in an ore zone which in places attains a length of 6000 ft. and a width of 4000 ft. They are most abundant in the Keewatin lavas in the neighborhood of the porphyry bodies. Few of the veins are persistent for long distances, though some

Jan 1, 1940

By H. L. Barr

THE following report covers the history of the development of the mine, present equipment, methods and costs of mining and milling. In addition, a description of the ore deposit is given with emphasis on the origin of the fractures, mode and types of ore occurrence, and mechanics of granite emplacement. An endeavor has been made to present a complete and accurate statement of the San Mauricio mine, the highest grade gold mine in the Philippine Islands. Credit is gratefully acknowledged to the mine staff for descriptions and details regarding their particular field of work. All analyses were made by Mr. T. A. DeVore, head chemist, San Mauricio Mining Co. Messrs. Edward Wisser, J. E. Fyfe, A. F. Skerl and W. B. Meek, geol-ogists, have contributed geologic information and ideas, for which thanks are extended. The Executive Committee of Marsman and Co., Inc., Managers of the Company, has kindly given permission for publication. Mr. J. B. Stapler, Division Manager, Marsman and Co., has had the courtesy to read the manuscript and to give critical and helpful suggestions.

Jan 1, 1940

By C. G. Brehm

The anthracite-producing region is in the northeastern section of Pennsylvania, and has an area of approximately 484 square miles. It is divided geographically into three separate fields, known as the Northern, Middle and Southern. The Northern field, with Wilkes-Barre approximately at its center, is a basin about 60 miles long and almost 6 miles wide at its greatest distance across. Generally speaking, it may be said that the coal measures in this field lie horizontally, or on slight pitches, and consist of from 11 to 19 veins of coal, varying in thickness from several inches to several feet. The intervening strata between veins may be composed of slate, clay, rock or shale, or a combination of several, and are sometimes very thin. This condition often causes a treacherous roof, therefore roof support and the attending hazard of mining are problems of concern. The Middle field is made up of a number of small basins of not very great depth, and the measures, which are in like number to those of the Northern field, are varying inclinations running from nearly flat to steep pitches. The Lower, or Southern field, is made up of basins of great depth, some being 4000 ft. deep, and its measures are mostly on very steep pitches. In certain sections this Southern field is being mined at an elevation of 1300 ft. below sea level, on a pitch ranging from 50' to practically vertical, and because of the tremendous pressure and the inherent gas in the seams, outbursts of coal frequently occur at the face, locally known as "bumps." These outbursts are accompanied by a rumbling noise, after which gas is usually found. This condition makes mining a difficult and extremely hazardous undertaking, and unusual skill is required on the part of the miner to drive and maintain openings necessary to the production of coal. Miners working in such seams on the heavy pitch must carry face batteries (Fig. 1) to afford proper protection while working at the face, because of the outbursts and free running coal. To drive haulageways or gangways in this field it is

Jan 1, 1940

By Warren B. Weeks

Continued development in the deeper fields discovered during 1937 and 1938 was largely responsible for the 16 per cent (2,913,400-bbl.) increase in production, bringing the 1939 output to 21,376,230 bbl., the largest for South Arkansas since 1929. The older settled fields continued to decline and Rodessa was added to this classification. Magnolia field accounted for much of the increase, with Schuler field showing only a slight increase. There were 248 wells drilled during 1939, five more than during the previous year. Of 198 wells drilled in proven fields, 21 were dry; 46 of the 50 wildcats drilled were dry. The old depth record of 8332 ft. was increased to the present record of 9028. Trend of Prospecting Production from the porous " Reynolds " oolite zone of the Smackover limestone continued to be the objective of prospecting. During the year 20 seismograph, 3 gravity meter, 1 magnetometer, 1 soil analysis and 1 electromagnetic crews were reported in the state. The geophysical work was largely concentrated in three southern counties: Columbia, Lafayette and Union. As indicated in Table 2, the same three counties received most of the important drilling tests. At the end of the year only three seismograph crews remained in the areas. The area for prospecting Smackover limestone was greatly narrowed during the year by the failure of two "fault zone" wells to find satisfactory permeability in the oolite zone, and by the relatively thin sections of porosity found in wells drilled in townships 18 and 19 South. Geology Most of the wells listed in Table 2 afforded additional control on structure of the lower beds, but gave little new information on stratigraphy. Of the 248 wells drilled, 3 ended in Tertiary, 34 in Gulf, 1 in Paluxy, 29 in Glen Rose, 15 in Travis Peak, 15 in Cotton Valley, 139 in Smackover, 2 in Eagle Mills and 10 in Carboniferous. The age of the beds between the Travis Peak formation and Carboniferous is still questionable. Most

Jan 1, 1940