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By W. B. Tucker

UNUSUAL interest has recently centered in the Mojave mining district of California, owing to new discoveries of gold ore at the Silver Queen mine, and subsequently at other neighboring proper- ties. These finds have proved that opportunities exist for the prospector even in old mining districts, where careful search may still be rewarded. The Mojave district is characterized by a group of small hills centering around Soledad Butte, four to six miles southwest of Mojave, in Kern County. This butte is 1250 ft. higher than the surrounding desert and 4000 ft. above sea level. Four miles west of Soledad Mountain are the so-called Middle Buttes, a group of flat-topped hills. Gold was first discovered in the district in 1894, and the following productive mines developed: Queen

Jan 1, 1936

By R. H. Hawkins

AN investigation of the applicability of geophysical methods to north-ern Ontario lignite deposits was undertaken early in 1930 by the Ontario Research Foundation at the request of the Ontario Department of Mines TABLE 1.-Formations Associated with Moose River Basin Maximum System Formation Lithology Observed Correlation Thickness, Ft. Pleistocene Marine clays 150 Glacial till (Minimum Interglacial 30) clay and peat Glacial till Lower Cretaceous or Mattagami Fireclay, sand 138 Kootenay (?) Upper Jurassic. and lignite Devonian (Upper) Long Rapids Petroliferous, 50 Portage and black and gray Genesee shale Williams Limestone and 87 Tully (?) Island calcareous shale Devonian (Middle).... Abitibi River Gray fossiliferous 65 Onondaga limestone Devonian (Lower) ?... Moose Rive- Limestone and 50 gypsum Devonian (Loner) Sextant Arkose, clay, etc. 50 Pre-Cambrian Syenite, granite gneiss, etc. Igneous intrusives. . Lamprophyre dikes cut the Abitibi River and lower formations. (Permission of Ontario Dept. of Mines) and was financed in part from a research grant made by the latter organ-ization. The work to date has included gravitational, magnetic and electrical resistivity studies. The gravitational and magnetic measure-

Jan 1, 1933

By Thomas V. Falkie

The use of operation research and computer techniques in the mineral industries continued to gain acceptance during 1966. There are generally at least five sources of information for researchers and practitioners in the field: (1) Technical periodicals like MINING ENGINEER- ING, Mining Congress Journal, etc. (2) Proceedings of the Symposium and Short Course on Computers and Operations Re- search in Mineral Industries, held last year at Penn. State University and jointly sponsored by the University of Arizona, Stanford University, Colorado School of Mines, Penn. State University and the Society of Mining Engineers of AIME. (3) Various local conferences, such as the 1966 Rocky Mountain Minerals Conference held in Denver. (4) United States Bureau of Mines publications. (5) The AIME annual meeting in New York and the SME Fall Meeting in Tampa.

Jan 2, 1967

By F. E. Bash

About three years ago, the writer presented a paper1 on the rate of heating and cooling of a 24-in. round ingot. The present paper deals with work done on larger ingots at the plant of the Allis Chalmers Mfg. Co., Milwaukee, Wis., in August, 1919. Sufficient data on ingots of all sizes were desired to enable one to calculate in advance the rate at which any ingot could be raised to a forging temperature without injury to the steel, determining also the temperature gradient between different sections of the ingot and the length of time necessary to heat to the center. This has now been experimentally determined for 24-in. and 45-in. ignots by the writer and for a 18-in. cube by E. F. Law.2 J. F. Harper has also made tests on heat-treating temperatures on 30-in, ingots; which data are included in this paper. No attempt is made here to work out a formula for the heat penetration of steel, for too many factors are involved concerning which we have not sufficient information, as for instance, the specific heat of steel up to 2300' F. It is hoped that eventually a set of formulas will be developed so that one may calculate maximum allowable temperature differences within an ingot for any particular kind of steel and the rate of absorption of heat and temperature gradient within the ingot for a definite temperature head. EXPEEIMENTAL INGOT The ingot tested was 45 in. in diameter, having been forged into the shape shown in Fig. 1 from 54 in. diameter. Seven -in. holes were

Jan 1, 1923

By F. E. Bash

About three years ago, the writer presented a paper1 on the rate of heating and cooling of a 24-in. round ingot. The present paper deals with work done on larger ingots at the plant of the Allis Chalmers Mfg. Co., Milwaukee, Wis., in August, 1919. Sufficient data on ingots of all sizes were desired to enable one to calculate in advance the rate at which any ingot could be raised to a forging temperature without injury to the steel, determining also the temperature gradient between different sections of the ingot and the length of time necessary to heat to the center. This has now been experimentally determined for 24-in. and 45-in. ignots by the writer and for a 18-in. cube by E. F. Law.2 J. F. Harper has also made tests on heat-treating temperatures on 30-in, ingots; which data are included in this paper. No attempt is made here to work out a formula for the heat penetration of steel, for too many factors are involved concerning which we have not sufficient information, as for instance, the specific heat of steel up to 2300' F. It is hoped that eventually a set of formulas will be developed so that one may calculate maximum allowable temperature differences within an ingot for any particular kind of steel and the rate of absorption of heat and temperature gradient within the ingot for a definite temperature head. EXPEEIMENTAL INGOT The ingot tested was 45 in. in diameter, having been forged into the shape shown in Fig. 1 from 54 in. diameter. Seven -in. holes were

Jan 1, 1923

By H. Y. Yancey, B. M. Bird

During the past four years the experimental work in coal washing carried on by the U. S. Bureau of Mines and the University of Washington has been devoted mainly to the development of special methods for the tabling of fine sizes of coals that are difficult to wash. One important outgrowth of this investigation has been the application of hindered-settling classification to coal tabling. Although used for many years in ore dressing, the term "classification" as used here may be new to many readers. It may be defined as the separation obtained when a bed of particles is held in a uniform state of suspension in an upward current of water, either continuous or pulsating, just sufficiently strong to keep the bed in a mobile condition. A common example of this type of separation is a jig in which there is no suction stroke. When the hindered-settling classifier is used with the coal-washing table, the fine-size raw coal, instead of being fed direct to tables, as is the prevailing practice, is first fed to the classifier and grouped, according to the rate of settling against the upward current of water, into perhaps six separate products. After dewatering, each of these except the sixth, a refuse product, is elevated to a seperate feed bin arid washed on a separate table. This paper gives a brief discussion of the basis for the use of hindered-settling classification of a table feed; a description of the experimental work; a comparison of the results obtained with and without classification; and a discussion of the application of the classifier in commercial coal washing. Basis for Use oF Hindered-settling Classification of Table Feed Although theoretical reasoning might be used to justify treating a table feed by hindered-settling classification,l the simplest method of demonstrating the need of such a step before tabling is to show the

Jan 1, 1930

By Burt A. Waite

The new OSM regulations for ground water monitoring of underground coal mines have been the source of many concerns for the mining industry. Because the regulations were initially written at the federal level, but are being administered at the state level, considerable confusion still exists within the industry as to what is really required. Based on submission and/or approval of more than 30 monitoring plans for existing mines in Pennsylvania, West Virginia, and Ohio, three basic sections are necessary. They are: 1. background data on the hydrogeologic setting of the mine, 2. the monitoring plan itself, and 3. mining procedures to minimize adverse effects on ground water. Like all of the OSM requirements, ground water monitoring will be a new burden the coal industry must bear, but with proper planning and communication with the regulatory authorities it need not be as bad as originally feared.

Jan 1, 1983

By J. H. Henderson, H. J. Ledbetter, N. B. Gove, J. D. Griffith

INTRODUCTION The results of a series of laboratory flood tests using liquid Iso-butane to displace refined oils from test cores are pre- ented and interpreted on an empirical bask. The study Revealed the similarity of the miscible liquid displacement to that of the immiscible-fluid displacement mechanism. The efficiency of the iso-butane flood decreased markedly as the oil Viscosity increased. but the effect of injection rate on the effectiveness of the primary production stage was negligible over the range investigated. The presence of free-gas saturation prior. to iso-butane breakthrough increased the volume of iso- Butane required to recover a given percentage of the oil present. Injection of liquid i.e.-butane prior to water follicle sculpted in a marked improvement in oil recovery by the water flood. INTRODUCTION The production of petroleum is often enhanced by the injec-1i1)n of extraneous fluids into the reservoir. It has been suggeited that the injection or cycling of a wet gas or a liquefied petroleum gas would he instrumental in increasing the effic.ienr!; of oil recover! to a greater degree than the commonly injected fluids. dry pas and water. Although instances of injection of light liquid hydrocarbons are not unknown, a systrmatic recording of the result is unavailable and superfi- cially, the practice gives the impression of being economicaIIy unsound. For specific types of displacement, analytic: solutions have been advanced which aid in understanding the physical mechanisms involved. However, there is no generalized theoretical concept which permits adequate prediction of displacement efficiency from a knowledge of readily measured reservoir rock and fluid properties. The Buckley-Leverett approach to oil displacement by an immiscible phase is an admirable analysiy of that type of mechanism. Dykstra and Parsons have introduced a useful concept in their evaluation of the role of the mobility ratio and its merit in rationalizing displacement phenomena. Everett, Gooch and Calhoun3 in their report on the effect of viscosity ratio and miscibility have pointed out the lack of a comprehensive theoretical approach and the desirability of investigating the mechanism of miscible-miscible displacement. In lieu of a well-developed theory concerning miscible-111isci1)le displacement and in view of the scarcity of engineering information on actual LPG injection trials, the limited program of laboratory experimentation described below was undertaken. OBJECTIVES The original broad objectives of the program, to study the oil recovery process using LPG as the displacing phase, defined the direction and scope of the laboratory tests. The specific objective. of the experimentation were to evaluate

Jan 1, 1953

Rossiter Worthington Raymond, Ph.D., LL. D-1840 to 1918.-Dr. Rossiter W. Raymond, Past President, Honorary Member and Secretary Emeritus, died suddenly of heart failure at his home, 123 Henry'St., Brooklyn, N. Y., on the evening of Tuesday, Dec. 31, 1918. He was one of the founders of the Institute and its second President. A Memorial 'Service will be held on Monday afternoon, Feb. 17. James Douglas.- The Institute suffered a second very severe loss by the death of Dr. James Douglas, Honorary Member, Past President (having served as President for two years), and in three separate respects the greatest benefactor of the Institute: first, in raising funds by volun¬tary subscription and his own personal gifts to pay the Institute's share of the money owed on the land on which the Engineering Societies Build¬ing now stands; second, as original donor to Engineering Societies Library; and third, by his bequest of $100,000 for the maintenance of the library of the American Institute of Mining Engineers. A resolution regarding the death of Dr. Douglas was passed by the Board of Directors and at the meeting of the Institute on Sept. 4, 1918, in Colorado, at which time a memorial service was held in the thea¬ter of the Hotel Broadmoor, attended by about 400 members and guests. A copy of the resolution was prepared and sent to the family. A bronze tablet is now being prepared and will be placed in the Members' Room and unveiled at the February meeting. A biography and portrait of Dr. Douglas was published in the September, 1918, Bulletin. There is also placed in the Engineering Societies Library an oil portrait of Dr. Douglas which had his own approval and was presented by him. American Institute of Metals.--During the Spring of the year, plans were completed with the American Institute of Metals whereby this society became the Institute of Metals Division of the American Insti¬tute of Mining Engineers. This body was a dignified aggregation of metallurgists which had been in existence for about 11 years. A bronze tablet commemorating the American Institute of Metals is now being placed in the Members' Room of the Institute, and during the year 1919 the Bulletin will bear the following title: "Bulletin of the American Institute of Mining Engineers, with which is consolidated the American Institute of Metals." Visits to Local Sections.-During the year President Jennings made visits to six of the Local Sections, on three of which occasions he was accompanied by the First Vice-president and the Secretary. First Vice-president Goodale made five visitations and the Secretary made eight.

Jan 1, 1923

By John Birkinbine

The following data, collected during a visit to the Snake river district, in Idaho, arc offered as indicating the possible utilization of a water-fall for irrigation by pumping, the working of gold-placers, the generation of electricity for light and power, and possibly for manufacturing purposes. For irriga-

Jan 1, 1901

By NEWTON B. KNOX

CHILEAN mining in the public mind is rightly associated with copper. Chuquicamata with its great hill of copper-bearing granodiorite as well as Sewell and Potrerillos with mineralized volcanic necks together can supply a good proportion of the world's normal necessities of that metal. Chile is an extremely long and narrow country, averaging only 109 miles wide. Its eastern frontier is the Andes and it is on the western slopes of these mountains that the great copper deposits have been discovered. West of the Andes a great longitudinal depres sion has permitted accumulation of nitrates and other soluble salts in the arid north; in the north center it is hidden by a series of cross ranges, but in the center a moderate rainfall makes it the country's most important agricultural region. In the south this depression is drowned and gives rise to a series of straits and fiords. This enormous cleft in the earth's crust is separated from the sea by a coast range of moderate elevation which in the south is represented by a series of islands and mushroom-shaped peninsulas

Jan 1, 1945

THE metal iron has physical and chemical properties which are somewhat different from those of steels, but a knowledge of the pure metal is a useful starting point in studying the behavior of steels. Solid iron exists in two different crystalline forms, called alpha (a) and gamma (?) iron, the former being the ordinary form at room temperature. When heated above the "A2 point," 768 C (1414 F), the metal becomes nonmagnetic, and at the "A, point," 910 C (1670 F), it undergoes a change in crystalline form to become gamma iron. In the range 768 to 910 C, it is sometimes called beta (ß) iron to distinguish it from the magnetic alpha, but the two are identical in crystal structure. When gamma iron is further heated to 1400 C (2552 E), it changes into delta (d) iron, which is identical with beta or non- magnetic alpha iron. Pure iron melts (in an inert atmosphere) at 1537 C (2800 F); the melting point is generally lowered by alloys or impurities. PROPERTIES OF IRON AT HIGH TEMPERATURES Many of the properties of iron undergo abrupt changes at the transition temperatures.1 For example, in heating through the A, point, a sudden shrinkage in volume occurs. Similarly, melting is attended by sharp physical changes such as an increase in volume. Table 16-1 contains a summary of the measured physical properties of pure iron at several temperatures. Usually the properties change smoothly within the range of stability of a given form, but this is not always true. For example, the specific heat reaches a sharp maximum at the A2 point although no trans- formation occurs. (See Fig 14-1.) Solvent Powers of Liquid Iron. Liquid iron is capable of dissolving most of the other metals and many nonmetallic elements as well. Of the metals that are liquid at the melting point of iron, only lead, silver, and bismuth refuse to dissolve to an ap-

Jan 1, 1951

By J. E. Berg

THE geology of the Coeur d'Alene mining district is so familiar to every one interested in mining that I will only note as an introduction that the main producers are mines whose orebodies lie in the Revett or Burke quartzites ; that the known orebodies in the eastern part of the district all lie north of the Osburn fault; that the Prichard formation is quite generally looked upon as being unfavorable for lead deposits ; that the monzonite intrusive mass extending north from Gem to Sunset Peak, and over into Cedar Creek divide, is considered to have been the prime agent in the crea-tion of our orebodies, and that diabase dikes are a quite common feature at most of the properties with which I am familiar. Some of the exceptions to these statements may be mentioned. The Interstate-Callahan mine is considered the exception disproving the alleged relation between large ore-deposits and the Prichard formation, but this property was primarily a zinc producer, with lead secondary, though of sufficient tonnage to be a valuable product. A second interesting occurrence in the Prichard worth calling to your attention is the Jack Waite property, on Tributary Creek, north of Murray. This vein lies at a low horizon in the Prichard forma-tion, and the ore differs essentially from others in the same horizon elsewhere in that it is a clean, medium to coarsely crystalline, lead ore carrying very little zinc, about one ounce silver to ten units lead, and is accom-panied by a clean quartz gangue or vein filling. I believe that quartz was the primary mineral in the fissure, and that the lead ore was deposited in the vein as a replacement of the quartz.

Jan 7, 1927

By L. R., McLeod

NO important changes in metallurgical practice are exhibited in the smelter that has been erected for treating the Morenci concentrate: the material is charged to reverberatory furnaces without roasting, and the matte subsequently blown in Peirce-Smith converters to separate the iron and sulphur from the copper. In fact the process is essentially the same, except for preliminary roasting of the concentrate, that was adopted in the new smelter that was built for the Arizona Copper Co. at Clifton, a few miles away, to treat Morenci concentrate just before the start of the first World War, and which went into service in October, 1913.

Jan 1, 1942

By AIME AIME

DREAMS do come true at times, although it is evidently better to believe in engineers than to "believe in fairies" if most dreams are to be translated into fact. It was a fine dream that David H. Moffat had when he projected a railway directly west from Denver; a dream of opening a new empire in northwestern Colorado, and of quickening transportation from the Middle West to the Pacific slope. But Moffat had been a miner and had become a banker. He knew that dreams, untranslated into works, benefit no one and pleasure only the dreamer, so he employed an engineer, H. A. Sumner, to study and plan the route to be followed by the rails. Previous main lines had run to the north, the Union Pacific, or the south, the Santa Fe. The Denver and Rio Grande, it is true, wriggled its way bravely across Colorado but, in order to reach a point 74 miles in an airline west of- Denver, travelled 281 miles following two canyons and crossing Tennessee Pass at 10,240 ft. Valuable as such a road is, it could never accomplish what Moffat had in mind. It was known that no low pass could be found directly west of Denver but up to 9000 ft. the topog-

Jan 1, 1925

By Stanley Rajnak, John E. Dorn

The saddle-point activation energy for the nu-cleation of a pair of kinks is estimated as a function of the applied stress, the lattice constants, and the height and shape of the Peierls' hill by employing the line-energy model of a dislocation. The kinetics of disloration motion by the Peierls' mechanism are discussed and the microscopic dislocation velocities and macroscopic strain rates are formulated by the Arrkenius type of approach in terms of the activation energy for the formation of pairs of PEIERLS was the first to illustrate that a straight-dislocation line has its lowest energy when it lies in a potential valley parallel to lines of closest packing kinks. The log of the dislocation velocity is found to be approximately proportional to the log of the local applied stress. It is also shown that the low-temperature mechmical properties of several bcc metals might be explained in terms of the Peierls mechanism, good agreement being obtained between theory and experiment for the flow stress us ternperature, activation energy vs stress, and activation volume us stress curves for these metals. of atoms on the slip plane. When such a straight dislocation is moved rigidly from one valley toward the next, the atoms in the vicinity of the core of the dislocation change their positions and bond angles, causing the energy of the dislocation to increase. Midway between two adjacent valleys, the disloca-tion energy reaches a maximum value and any additional small displacement will cause the dislocation to fall down the hill into the next valley. The maximum shear stress necessary to promote such

Jan 1, 1964

By Fred C., Bond

IN CYANIDE milling, little attention has been paid to the effect of the viscosity of the mill solution on the extraction speed. The viscosity of the solution varies with the amount of dissolved salts present as impurities. These salts build up to a maximum depending on the character of the ore, the grade of cyanide used, the lime and salts added, and the impurities originally in the water. The viscosity will change from month to month and week to week as these factors vary; and that this variation affects the extraction is unquestioned, although methods for calculating it are lacking. The character of the ore is probably the most important of the four factors, as the amount of minerals present that are soluble in cyanide solution will vary constantly, and each variation affects the viscosity of the mill solution. When the cyanide consumption increases as the character of the ore changes, the viscosity of the solution will increase and the extraction will decrease, for the cyanide consumption is usually a measure of the impurities dissolved from the ore. In other words, as the difference between the total and free cyanide increases the extraction will decrease, other factors remaining constant.

Jan 1, 1926

By G. F. LOUCHLIN

A FEATURE of the International Geological Congress to be held at Pretoria, South Africa, in the summer of 1929,. will be a symposium on the gold resources of the world. In this connection the U. S. Geological Survey and Bureau of Mines have been asked to prepare a report, showing production in the United States, describing the geology of its principal gold- producing districts, and estimating reserves (a) assuming a continuation of presen6economic conditions, and (b) assuming lower costs. This report will not be completed before April 1, but data thus far assembled are here presented with the hope of profiting by discussion and by information from those well informed on any of the important gold-producing districts. Gold production in the United States rose to a maximum exceeding $100,000,000 in 1915 and then rapidly declined to about $52,000,000 in 1920. Since then it has fluctuated, but on the whole slightly declined. Reviews of the eight leading states afford the following tentative conclusions :

Jan 1, 1929

By AIME AIME

BLANDFORD. C. BURGESS, the new Chairman of the Industrial Minerals Division, took the advice of Horace Greeley in reverse-he turned his hack on San Francisco and the Golden Gate, and after a few side excursions toward Alaska and Arizona, hit the trail eastward, not for the lonesome pine, but for Spruce Pine, N. C. Born Aug. 10, 1893, in San Francisco. Burgess found his first job, shortly after finishing high school at 19, as axeman for a surveying party of engineers working for the Southern Pacific Co. in Oregon. Later he moved on up with them into Alaska. He liked the engineering profession, and decided to equip himself further so he entered the University of California in the fall of 1913. and for the next two years devoted himself to acquiring an education in civil engineering.

Jan 1, 1945

By F. X. Meyer

THE United States Smelting Refining and Mining Company maintains an ore-purchasing department for procurement of custom tonnages of milling and smelting ores and concentrates for treatment at its Midvale plant. Arrangements with other companies provide for treatment of Company and custom zinc concentrates. Location of the Midvale plant in the heart of the Western mining country makes it possible to serve shippers from these nine producing states: Arizona, California, Colorado, Idaho, Montana, Nevada, Oregon, Utah, and Washington. Shipments from most of these states travel over main-line railroads, delivery being made at Midvale within a short time after billing of the shipment. Shipments varying in size from a few sacks to carloads can be handled at

Jan 1, 1948