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By Tom Westgarth

As papers are placed before you upon large gas-engines in Belgium and Germany, it was considered that some information should be given upon the same subject in Great Britain. I therefore agreed to compile these notes, which I have made very short in view of the somewhat full nature of the other papers presented to this meeting, and considering the complete nature of the many publications which have been made recently upon the subject of large gas-engines. I give below Tables I. to VI., showing the number and particulars of large gas-engines which have been built or are building by British makers, and in view of the growing size of gas-engines I have concluded that engines of less than 500 h.p. cannot now he included in the category of large gas-engines, and therefore I have not considered engines under that power. Table I.—-" Oechelhauser " Type Gas-Engines. Built or Building by William Beardmore Co., Limited, Glasgow Indicated ! Engines. Horse-Power Type. Nature of Work. Gas Used. 6 2,500 Twin cylinder. Dynamo. Producer. 1 in Single cylinder. Rolling-mill. Producer. 4 1,250 Twin cylinder. Dynamo. Producer. 2 1,250 Single cylinder. Dynamo. Producer. 4 625 Single cylinder. Dynamo. Producer. 1 625 Single cylinder. Rolling-mill. Producer. 1 625 Single cylinder. Air compressor. Producer. 2 500 Single cylinder. Air compressor. Producer. 7 500 Single cylinder. Cement-mill driving Producer. Total, 28 engines ; 32,600 indicated horse-power. * Presented at the Joint Meeting of the Iron and Steel Institute and the American Institute of Mining Engineers, London, July, 1906, and here published under a mutual agreement between the Councils of the two Institutes.

Jan 1, 1907

By William Fink

THE investigation of the phase relations of high-purity aluminum-base alloys is a part of the fundamental research program of the laboratories of the Aluminum Company of America. The results of a number of binary and ternary systems have previously been published in the transactions of this society. The aluminum end of the binary aluminum-titanium system has been studied. This system has received relatively little attention. To the authors' knowledge, there are two previous papers on this subject. E. van Erckelens1 determined the constitutional diagram reproduced in Fig. 1. .According, to this diagram, the liquids represents the separation of TiAl4 (Ti = 30.7 per cent.). He concluded that this is the composition of the compound, because in his work the eutectic horizontal terminated at 30.7 per cent. titanium and the metallographic examination of a sample of this composition revealed only one phase. According to the constitutional diagram developed by W. Manchot and A. Leber,2 reproduced in Fig. 2 from data given in their article, the liquidus represents the separation of the compound TiAl3 (Ti = 37.2 per cent. ). The composition of the compound was derived in a manner similar to that utilized by van Erckelens. Moreover, Manchot and Leber confirmed the composition of the compound by analysis of the constituent left as a residue after dissolving the alloys in weak sodium hydroxide solution. Although these are the only publications describing the constitution of the system, other investigators have studied the composition of the titanium compound. L. Wöhler3 says that there is a compound TiAl3 which was later confirmed by W. Manchot and P. Richter4 and by

Jan 1, 1931

By R. J. Jackson, D. E. Williams, W. L. Larsen

The phase diagram of the Ta-Zr system is presented with a discussion of the methods used in its determination. The solidus contains a minimum at 1820°C near 25 wt pet Ta. A complete solid solution exists at elevated temperatures between tantalum and ß zirconium. This solid solution decomposes monotectoidally at 800°C and 12 wt pet Ta. The maximum solubility of tantalum in a zirconium is slightly less than 2 wt pet, and decreases with decreasing temperature. The solubility of zirconium in tantalum is 5 wt pet at the monotectoid temperature and about 2 wt pet at room temperature. THIS investigation was part of a program of research on refractory metal alloy systems having potential application in nuclear reactor technology. Preliminary prop-ess has been reported in the Ames Laboratory annual research reports.l Most of the previously reported work on the Ta-Zr alloy system consisted of partial phase diagram investigations and the determination of the mechanical properties of the zirconium-rich alloys. Anderson eta1.2 studied alloys containing up to 30 wt pet Ta as part of an investigation of several zirconium alloy systems. These investigators also determined some of the mechanical properties of the alloys at room temperature and 650°C. In a discussion of Anderson's work, Pfei13 suggested that the bright phase in the microstructures of the intermediate alloys is a tantalum-rich solid solution or an intermediate phase in a matrix of ß zirconium solid solution. Litton,4 Keeler,5 and Chubb6 determined the mechanical properties of zirconium-rich alloys at ambient and elevated temperatures. Van Thyne and McPherson7 reported the tensile properties

Jan 1, 1962

HeRbert A. MeGRaw, San Luis de la Paz, Guanajuato, Mex. (communication to the Secretary*) :—Although Mr. Bordeaux prefaces his paper with the statement-that it is a general outline of practice in the Republic, many of his statements seem to be made from the view-point of a particular case, which does not always agree with general practice. For the purpose of calling attention to some of these variations, I respectfully offer the following comments: The operation of crushing and grinding is performed by so many different methods and systems that it is useless to select any one as the standard. However, primary crushing in rock-breakers followed by stamps is thus far so general that it might be so classified. Whether or not it is the best way, is open to question. Regrinding may be performed by any of the various types of Chilean mills, Huntington mills, or similar machines, or the material may be taken directly from the stamps and delivered to the tube-mills. Mr. Bordeaux's statement that " the slimes can be treated only by decantation; the new Butters slime-filter, as used in Nevada, does not seem to be successful with silver-ores," is surely an error. All over Mexico many of the purely silver-ores are being successfully handled by the Butters or similar filters, such as the Moore and the Burt filters, and a letter to the manufacturers of these filters will undoubtedly bring a list of the silver-ores now being successfully treated in this way. The statement that crushing silver-ores in solution is impossible is equally erroneous. Most modern mills crush the ore in solution, in some cases containing as much as 0.12 per cent, of KCN. I cannot for the moment recall any modern mill in Mexico which does not follow this practice. There may be some reason for it in particular instances, but, generally speaking, the practice is to crush in solution. Care in installation avoids any mechanical loss of cyanide, and the chemical loss is so small as to be negligible.

Jan 1, 1910

By Paul Billingsley, Augustus Locke

The mining districts of the first order' of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of compressive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 Nature of the Thrust Arc The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The. cross-sections are as shown in Fig. 2. The backbone of the belt is the upward and eastward moving block represented by the Glacier Park, the Wasatch, and the Virgin mountains, successively. The structure represented on these sections is the culmination of events which began far back in geologic time and throughout which a contrast has existed between the regions east and west of the backbone line. Before the Pennsylvanian, as Fig. 3 shows, there was a shallow shelf on the east and a deep marine trough on the west; after

Jan 1, 1935

By Paul Billingsley, Augustus Locke

The mining districts of the first order' of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of compressive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 Nature of the Thrust Arc The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The. cross-sections are as shown in Fig. 2. The backbone of the belt is the upward and eastward moving block represented by the Glacier Park, the Wasatch, and the Virgin mountains, successively. The structure represented on these sections is the culmination of events which began far back in geologic time and throughout which a contrast has existed between the regions east and west of the backbone line. Before the Pennsylvanian, as Fig. 3 shows, there was a shallow shelf on the east and a deep marine trough on the west; after

Jan 1, 1935

The mining districts of the first order' of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of compressive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 Nature of the Thrust Arc The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The. cross-sections are as shown in Fig. 2. The backbone of the belt is the upward and eastward moving block represented by the Glacier Park, the Wasatch, and the Virgin mountains, successively. The structure represented on these sections is the culmination of events which began far back in geologic time and throughout which a contrast has existed between the regions east and west of the backbone line. Before the Pennsylvanian, as Fig. 3 shows, there was a shallow shelf on the east and a deep marine trough on the west; after

Jan 1, 1935

By Augustus Locke, Paul Billingsley

The mining districts of the first order' of the western United States (and borders) are those named on Fig. 1. These fall into four groups: (1) in the eastern outliers of the Rocky Mountain system; (2) in the Rocky Mountain system itself; (3) in the Great Basin; and (4) in the Sierras and Coast ranges. Of these four groups, the first three are almost entirely of Tertiary age and are within a belt of compressive folding which we shall call the Rocky Mountain-Great Basin thrust arc. The backbone of this belt is shown by the line BAC. The position of the ore districts in this belt indicates a conformance to linear elements of the continental pattern. These are additional to the peripheral elements emphasized by Butler.2 Nature of the Thrust Arc The thrust arc separates regions of contrasted kinds. To the east of it are flat-lying plateaus interrupted by earlier mountain folds; to the west, sunken basins, in which block-faulted ranges lie like an anchored fleet in a sea of desert wash or lava. The. cross-sections are as shown in Fig. 2. The backbone of the belt is the upward and eastward moving block represented by the Glacier Park, the Wasatch, and the Virgin mountains, successively. The structure represented on these sections is the culmination of events which began far back in geologic time and throughout which a contrast has existed between the regions east and west of the backbone line. Before the Pennsylvanian, as Fig. 3 shows, there was a shallow shelf on the east and a deep marine trough on the west; after

Jan 1, 1935

By J. H. Bowden

The shaft-plant here described was put in operation in September, 1895, and the No. 6 slope-motor was started in May, 1896. The plant comprises : One Norwalk three-stage compressor l21/2, 91/2 and 5 in. diameters of air- and 20 in. diameter of steam-cylinder, all 24 in. stroke; capacity at 100 revolutions, 296 cu. ft. of free air per minute, compressed to 600 Ibs. per sq. in. A main pipe, 5 in. diameter, 4380 ft. long, with five charging-stations in No. 6 Shaft, and a branch of 3 in. pipe, 3100 ft. long, with three charging stations, in No. 6 Slope. These pipes on each line charge a Porter compressed-air motor, with 7 by 14 in. cylinders, and four 24 in. drivers, weighing about eight tons, with a tank-capacity of 130 cu. ft. of air at 550 lbs. pressure in the main tank, reduced to 160 lbs. in the 8-in. auxiliary tank of 4.2 cu. ft. capacity, supplying the cylinders. The No. 6 shaft run averages 4000 ft. each way on grades of $ to 23/4 per cent., and averaging close to one per cent. in favor of the loaded cars. The No. 6 slope run averages 2100 ft. with nearly the same grades. The mine-cars weigh 2800 Ibs. empty, and about 9800 lbs. loaded, and are hauled in trips of 12 to 20, averaging about 15 cars. The shaft-motor now hauls about 355, and the slope-motor 320 cars per day of 10 hours, replacing in the shaft 17 mules, and

Jan 1, 1901

By Gordon H. Chambers

MANGANESE ore is a true jack-of-all trades among industrial minerals, its only possible rival being iron ore. It is used in porcelain enamel, dry batteries, building brick, glazed pottery, floor tile, plastics, welding rods, chemicals, and varnish. You may be reading this through spectacles decolorized with manganese, and the light bulb above you contains some of this element. GEOLOGY Nearly all commercial manganese oxide deposits are of secondary origin; that is, they are concentrated by weathering from other manganese minerals more sparsely distributed in veins. The oxide minerals usually form irregular masses but in some places (Russia) they occur as beds of varying thickness and purity. Some manganese oxide bodies occur in soft gravel or clay formations but in other places the minerals are found in the form of veins and rounded nodules in limestone and other hard rocks. The geologic features of manganese deposits closely resemble those of iron deposits. Classification of the deposits is shown in the following table: I. Classification of manganese deposits based upon form of occurrence A. Stratiform masses 1. Oxides interlayered with sediments or layered volcanic or metamorphic rocks 2. Carbonates or silicates interlayered with sediments or layered volcanic or metamorphic rocks 3. Oxides, as surface bog deposits B. Veins and breccia filling 1. Oxides in larger part 2. Carbonates or silicates partly weathered to oxides C. Irregular masses 1. Oxides 2. Carbonates or silicates largely weathered to oxides D. Aggregates of small oxides in clay or weathered rocks 1. Mainly oxides E. Unclassified deposits II Classification of manganese deposits based upon mode of origin A. Hydrothermal deposits

Jan 1, 1949

By A. L. Volley

(Read at the Amenia Meeting, October, 1877.) THE existence of iron ore and anthracite coal in the neighborhood of Providence, R. I., has long been known, chiefly as a geological fact; that these materials, so near to each other and to tidewater, are of such a good quality and are present in such large quantity, as to have seriously raised the question of establishing blast furnaces there, was a surprising fact to me; and I have thought that the few notes I have lately gathered on the subject would be of interest at this partly New England meeting. The coal field referred to has an area of above 400 square miles, and is found throughout the belt of transition rocks extending from Newport Neck to Mansfield, Massachusetts. It underlies the cities of Providence and Newport, and the towns of Middletown, Portsmouth, Jamestown, Warwick, Barrington, Cranston, North Provi-

Jan 1, 1878

By George B. Lee

DURING The Two Years In Which The New Reduction-Works Of The Copper Queen Consolidated Mining Co. Have Been In Operation At Douglas, Ariz., There Has Developed A Remarkable Condition In Regard To The Corrosive Action Of The Water Used To Cool The Jackets Of The Blast-Furnaces. Were It Not For The Many Contradictory Features, It Might Pass As One Of The Unavoidable Troubles Due To The Composition Of The Water. This Water, Obtained From Wells 600 Ft. Deep, Is Also Used In The Steam-Boilers, And Its Composition, As Shown By The Following Analysis, Does Not Indicate The Presence Of Any Ingredient Which Would Explain The Corrosion Grains Per U. S. Gal. Silica, 0.861 Iron Oxide And Alumina, 0.223 Calcium Carbonate, 0.2111 Calcium Sulphate, Magnesium Carbonate, Sodium And Potassium Sulphates, . 14.850 Sodium And Potassium Chlorides, 9.732 Sodium And Potassium Carbonate, 6.452 32.409 The Jackets Are Made Of Inner Plates 0.5 In. Thick And An Outer Plate I In. Thick, With 3-In. Stiffeners Between The Inner And Outer Plates. In From 10 To 12 Months The Inner Plates Have Been Reduced By Corrosion To A Thickness Of From 1/8 To 1/16 In., While The Outer Plate In The Same Time Is Reduced By Less Than 1/16 In., And The Stiffeners Show Very Little Corrosion. The Plates Are Pitted And Eaten Away In Some Places More Than In Others. There Is Practically No Scale Found On The Jackets, But When Cleaned Considerable Iron Oxide Is Found In The Bottoms. With An Action So Marked, Serious Trouble Would Be Expected In The Boilers, But, On The Contrary, A Recent Inspection By a

Mar 1, 1908

By John Vanderwilt

THE value of molybdenum as a ferroalloy has been known for many years. For a long time, however, the metal was used only on a small scale in the iron industries, because the known source of supply appeared inadequate and the cost to the consumer was not stabilized. The world's production of molybdenum prior to 1914 was only a few thousand pounds per year and even during the war period annual production was only about 800,000 lb. Production during 1929 and 1930, however, was over 4,000,000 lb. per year and that of 1931 promises to be of the same order of magnitude. This remarkable increase in production is due primarily to the development of a large molybdenite deposit at Climax, Lake County, Colo., which has accounted for 80 per cent of the world's production of molybdenum during the past two years. Based on conservative esti-mates, the deposit at Climax has the capacity to maintain its 1929 and 1930 rate of production for 100 years or more. The production of molybdenum ores has been established on a new basis-in recent years as compared with the period during and before the world war. During the earlier period, production came from small deposits and the cost to the consumer fluctuated. At present, production comes from a few large deposits and the price is not only lower but also fairly constant. In recent years the price of molybdenum has consistently dropped as consumption increased. The present price is $0.95 per pound of molybdenum in ferromolybdenum and $0.80 for molybdenum in calcium molybdate. Before and during most of the war, Australia, Norway, and a few other foreign countries were the chief producers, while at present the United States is producing over 90 per cent of the world's production. With molybdenum available at a moderate cost, the steel industry has been adopting more and more the use of molybdenum as an alloy addition. A relatively small demand for molybdenum exists in the chemical and electrical industries, but the recent large increase in con-sumption has in large part been by the iron and steel industries, which

Jan 1, 1932

By R. C. Ferguson, Harlowe Hardinge

Laboratory and plant data covering 12 different operations show that lower than "standard" ball mill speeds increase grinding efficiency. In the case of high pulp-level mills, the gain is so great that the increase in capital cost of the larger lower speed mill will pay for itself in less than a year's time. THE object of this paper is to show the economic advantage of operating ball mills at relatively slow speeds. Although many operators know that grinding costs are reduced by operating mills at low speeds, they seldom do so for a variety of reasons. When capital is limited, first cost is of primary importance, and installation of the less costly, highspeed mill is favored. When materials are in short supply, as during a war period, capacity rather than economy is the primary consideration. Existing mills are then speeded up to provide the desired increase in capacity, and new mills are purchased without consideration of maximum grinding efficiency. When the mill speed is increased to secure more production, the increase in grinding costs is often obscured by the total benefit derived from the additional output. This increase in grinding cost is seldom recognized as being sufficient to be worth correcting. For these reasons one may be lead to the erroneous conclusion that slow-speed operation is only occasionally applicable. The effect of mill speed on grinding efficiency has been studied in laboratory tests."! The results of some of these tests are given in tables I and I1 and fig. 1. In these tabulations, batch tests using ore charges of 125 to 200 lb were considered comparable to high pulp-level operation and charges of 50 to 100 lb comparable to low pulp-level operation. For the high pulp-level operation, these tests indicate the existence of a maximum in efficiency for operation at a speed of 50 pct of critical, both for the soft (dolomite) and hard (chert) ore. In low pulp-level operation, a decrease in speed increases the efficiency of grinding dolomite; no maximum of efficiency appears in the range of speeds tested. The results with chert were inconclusive. If the performance of large mills is indicated

Jan 1, 1951

By Harlowe Hardinge, R. C. Ferguson

Laboratory and plant data covering 12 different operations show that lower than "standard" ball mill speeds increase grinding efficiency. In the case of high pulp-level mills, the gain is so great that the increase in capital cost of the larger lower speed mill will pay for itself in less than a year's time. THE object of this paper is to show the economic advantage of operating ball mills at relatively slow speeds. Although many operators know that grinding costs are reduced by operating mills at low speeds, they seldom do so for a variety of reasons. When capital is limited, first cost is of primary importance, and installation of the less costly, highspeed mill is favored. When materials are in short supply, as during a war period, capacity rather than economy is the primary consideration. Existing mills are then speeded up to provide the desired increase in capacity, and new mills are purchased without consideration of maximum grinding efficiency. When the mill speed is increased to secure more production, the increase in grinding costs is often obscured by the total benefit derived from the additional output. This increase in grinding cost is seldom recognized as being sufficient to be worth correcting. For these reasons one may be lead to the erroneous conclusion that slow-speed operation is only occasionally applicable. The effect of mill speed on grinding efficiency has been studied in laboratory tests."! The results of some of these tests are given in tables I and I1 and fig. 1. In these tabulations, batch tests using ore charges of 125 to 200 lb were considered comparable to high pulp-level operation and charges of 50 to 100 lb comparable to low pulp-level operation. For the high pulp-level operation, these tests indicate the existence of a maximum in efficiency for operation at a speed of 50 pct of critical, both for the soft (dolomite) and hard (chert) ore. In low pulp-level operation, a decrease in speed increases the efficiency of grinding dolomite; no maximum of efficiency appears in the range of speeds tested. The results with chert were inconclusive. If the performance of large mills is indicated

Jan 1, 1951

By Earl R. Johnson

Ore broken at the mine or quarry face generally is loaded by power shovels into large trucks or rail cars and hauled to a primary crushing plant where it is reduced to a more workable size for ease in handling. The primary crushing plant is customarily located as close as possible to the center of gravity of the ore body and the projected limits of the mine pit to minimize the cost of hauling and to increase safety from flying rock as a result of blasting operations. A belt conveyor is used to transport the crushed product to a nearby ore treatment plant or, should this plant be located some distance away, the ore is loaded directly into cars and hauled by rail. Between trips the crusher product is accumulated in bins or stock piles. In all open pit mining and quarrying operations, the power shovel, the transportation equipment, and the primary crushing plant should work as a team, complementing each other. When establishing the design and selecting the equipment for these closely integrated operations, capital and operating costs for each unit operation must be weighed to achieve an optimum balance. Rising labor costs have given impetus to the universal trend toward greater efficiency, higher speed and larger equipment, and higher degrees of automatic control. The result is that power shovels have increased in size, haulage trucks are larger and faster, and only coarse crushers with feed openings adequate to receive run-of-mine lumps of ore with a minimum of secondary blasting are selected for new installations. These coarse crushers also have large through-put capacities, even when adjusted to produce a 6- to 10-in. size of product, thus making it possible to use a single stage of coarse crushing at the average mine. The use of a single crusher results in a compact crushing plant layout consisting of a dumping pocket for receiving loads of run-of-mine ore, a coarse crusher followed by a surge chamber for the crushed product, and a feeder to withdraw the ore at a uniform rate to deposit it on a belt conveyor. A

Jan 1, 1968

By R. G. Knickerbocker

The copper smelter and refinery of The Messina (Transvaal) Development Co. Ltd., at Messina, South Africa, was erected in 1920 and 1921, but initial operations were deferred until late in 1922 on account of the collapse of the copper market in the interim. Because the anticipated production was to be only 20 tons of copper per day from a high-grade matte containing 60 per cent copper, and because the ore did not contain gold or silver in quantities sufficient to pay for separation from the copper bullion, it was decided to design the plant along lines quite different from the modern smelteries treating large quantities of sulfide ores carrying appreciable amounts of gold and silver. The plant was built, therefore, for the production of copper by the Nicholls-James process. By this method two-thirds of the copper matte produced was roasted in a Merton calciner and charged into a bath of the remaining one-third portion of unroasted matte in a reaction furnace. The original design was not only novel in providing for the Nicholls-James process, but also in comparison with new plants built elsewhere, because of factors inherent in the locality. Sources of supply for machinery were very remote; it takes three months after the placing of an order to accomplish delivery of machinery into Messina from the United States. Native labor was available at 30 to 40¢ per 8-hr. shift. These factors permitted plant design which provided no overhead cranes, no matte ladles, no slag pots or other usual mechanical means of transportation between departments. The design resulted in a compact simple plant with furnaces arranged close together and terraced so as to provide for gravity transfer of molten material from one furnace to another and for manual disposal of products. Fig. 1 shows the relative location of furnaces. The three furnaces are parallel on successively decreasing elevations. A superimposed feed floor was provided above the furnaces. All three furnaces were provided with coal-dust burners served from a Bonnot system of coal-dust transportation, and the waste gases were discharged into waste-heat boilers. A short trial of the Nicholls-James process developed several facts which brought about a decision to abandon the process. Owing to the

Jan 1, 1934

By D. Jenkins

THE Franklin Laboratory was designed mainly for the analysis of the products from the two concentrating mills situated at Franklin and Sterling Hill, the most important determinations being the zinc, iron, manganese, lime, moisture and silica contents of the ores. Within the last 4 years, however, it has been found advisable to examine most of our supplies, and therefore additional space and equipment was allotted for the examination of such substances as oils, greases, soaps, alloys, fuels, paints, explosives and water. The building as shown in elevation (Fig. 1) and plan (Fig. 2) consists of a main or routine laboratory, an experimental laboratory, a water FIG. 1.-WEST ELEVATION. analysis room and the other accessories such as stock room, library, sampling and drying rooms and office. The main laboratory is further divided into a balance room and zinc analysis room. As the greater part of our determinations are volumetric, good light is a very important factor and with this in view the interior walls of the building were constructed of white enameled brick laid in Keene cement. These also have the additional advantage that they give a clean and attractive appearance to the room. The windows are large, being 76 by 44 in. and even on very dark days the light is good throughout the whole laboratory. Our zinc titration requires a constant light and as, on many days, especially in winter, the light is variable, we installed two Artificial

Jan 8, 1917

By L. G. E. Bignell, E. A. Hanson, J. O. Lewis

There was a general upward trend of all petroleum activities in Oklahoma during 1933, especially in the last quarter, though the average price for crude oil for the year was below 1932 and overproduction in East Texas demoralized conditions for several months. As the Federal Agencies established under the National Industry Recovery Act began to function conditions in Oklahoma were visibly affected and production of "hot oil" from Oklahoma City field practically ceased. More oil wells were completed, six new fields discovered, extensive geophysical prospecting carried on in many parts of the state, and an increased amount of clean-out and reconditioning work done in older pools during the past year. To increase quantity and rate of recovery of oil many wells producing from limestone formations were treated with hydrochloric acid. The Oklahoma City field had a reported production of 66,984,570 bbl. of oil during 1933, or almost exactly twice the amount reported for 1932. Potential tests and other indicators show that the wells are rapidly approaching the stage where mechanical lift must be applied to all of them, including the wells in the Wilcox sand zone. The major pipe-line companies serving the oil fields of Oklahoma have been anxious to make connections to all wells during 1933 and have indicated a willingness to accept all oil available. The amount offered has been restricted by proration orders, but the state did produce 178,356,-449 bbl. during the year, an increase of about 18.6 per cent over 1932. This increase was practically all due to the greater demand for Oklahoma City oil, as all other pools of any importance showed loss in production or very small gains last year. The U. S. Bureau of Mines' laboratory reports the lubricating distillate content of Oklahoma City crude from Arbuckle and Lower Simpson formations about 17 per cent by volume. East Texas oil is reported to contain about 5.6 per cent lubricating distillates. The desire of the transportation companies to keep their equipment operating at maximum capacity and the need of some refineries for more

Jan 1, 1934

By D. R. Walker, M. C. Shaw

The laws of Kick and Rittinger are explained as functions of particle size with metal cutting theory. Comminution is shown to be basically the same process as metal grinding. The machine shop type of grinding operation is used to study mineral crushing. Evidence indicates that plastic flow occurs in comminution. THE laws of comminution of Kick and Rittinger have been debated for many years. Certain data obtained from ball mill and drop tests are found to be in approximate agreement with Rittinger's law while other data would seem to support Kick's law. In all these tests the energy required to produce a wide variety of particle sizes has been studied. Surface area has also been measured with considerable difficulty, at first because it was thought that the energy associated with crushing was that required to create new surface, later because of precedent and because a more fundamental variable was unknown. Tests made with the machine shop type of grinding process show that normally brittle materials that are usually crushed can behave like the more ductile metals. Brittleness is then a relative prop- erty largely dependent on specimen size and stress state. The machine grinding operation offers a convenient means for studying the comminution of materials in which the important size variable retains its identity. The energy required to grind a certain volume of material is shown to be strongly dependent on size. Kick's law is found to hold very well for particles below 1 micron in size, while Rittinger's law holds approximately in the comminution of larger particles. While a physical origin of Kick's law is established in terms of the theoretical strength of materials having a perfect lattice structure, there is found to be no physical basis for Rittinger's law. Because of its industrial importance, comminution has commanded considerable technical attention and has been the subject of continuous study for nearly a century. A number of empirical rules have been proposed to make it possible for grinding energies to be predicted. Of these so-called laws of comminution those bearing the names of Kick and Rittinger have been most widely applied and debated.

Jan 1, 1955