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By George M. Fowler

DURING 1937 the subject of mining geology was probably given more attention and more mining geologists were usefully employed than at any previous time. Of the many contributing factors the most important were: (1) a higher degree of prosperity in many countries, (2) a. better understanding of geologic phenomena, and (3) the apparently diminishing reserves of several important minerals. Mining companies have come to look upon geology with a growing appreciation of its aid in the more effective exploration and exploitation of mineral deposits. Most of the larger and more active companies have one or more geologists permanently attached to their staffs and some have well organized and efficiently managed geological departments. Even the smaller companies, who feel they cannot afford to employ a geologist on a permanent basis, are seeking the advice of competent men in this field with increasing frequency. One of the most significant trends has been the growing tendency to base exploratory work on more thorough geologic studies instead of empirical "hunches,"on which so much off the work in the past has relied. Likewise, mining companies are apparently more willing to expend larger sums on the basis of geologic possibilities in a district.

Jan 1, 1938

[Separates of all the Technical Publications published in 1928 are available at Institute headquarters. All the papers are on file in public, university and technical libraries, and when so indicated in the list, may be found either in the TRANSACTIONS or in the special volumes issued by the Institute.; METAL MINING TECH- NICAL TRANS. PUBLI- TITLE AUTHOR MEETING VOLUME CATION AND PAGE* No. 50 The Eötvös Torsion Balance D. C. Barton New York Method of Mapping Geologic Feb., 1928 Structure 52 A Cartographic Correction for the C. A. Heiland New York Eötvös Torsion Balance Feb., 1928 61 Liquid-oxygen Blasting at Chuqui- H. C. Schultz, New York camata, Chile F. K. Middleton Hunter Feb., 1928 76, 108, 123 64 Working Methods of Practical Geo- Hans Haalck New York physics Feb., 1928 65 Experiments with Eötvös Torsion P. W. George New York Balance in the Tri-State Zinc and Feb., 1928 Lead District 74 Gravity Surveying in Great Britain H. Shaw New York Feb., 1928 75 The Computation of Eötvös Gravity E. Lancaster-Jones New York Effects Feb., 1928 82 Earth-resistivity Measurements in W. O. Hotchkiss, New York the Lake Superior Copper Country W. J. Rooney, Feb., 1928 James Fisher 83 Mining Methods and Records at the Roy W. Moore New York 76, 56, 90 United Eastern Mine Feb., 1928 98 Recent Results in Electrical Pros- Hans Lundberg New York specting for Ore Feb., 1928 101 Relation between the Oxygen Bal- G. St. J. Perrott, New York ance and Propulsive Strength of N. A. Tolch, Feb., 1928 Eight Gelatin Dynamites J. E. Crawshaw 102 Effect of Oxygen Balance of Gelatin G. W. Jones, New York Dynamites on the Gaseous Prod- G. St. J. Perrott Feb., 1928 ucts of Detonation 108 The Financial Report of a Min- Henry B. Fernald New York ing Company-Its Content and Feb., 1928 Meaning 116 What Duty to Support the Surface R. G. Bosworth New York Does a Subsurface Owner Owe? Feb., 1927 136 Comparison of Branch Raise and C. A. Mitke Los Angeles 76, 93, 103 Combined Shrinkage and Caving Sept., 1928 Methods 141 A Mining Company Balance Sheet G. F. Wolff New York Feb., 1928

Jan 1, 1927

By Duncan MacVichie

The iron fields described here are located in the Iron Springs and Pinto mining districts, Iron County, Utah. This region is in southwestern Utah, about 260 miles south from Salt Lake City, and is reached by the Los Angeles & Salt Lake railroad of the Union Pacific system. The iron fields lie at an elevation of 5500 to 7500 ft. above sea level, and are essentially desert in character. They are covered with a light growth of sage brush, piñon pine, and scattered cedar. Weather conditions are unusually favorable for all-year mining operations, the winters being mild with little or no snow; and the summers not excessively hot, the temperature rarely rising to 100 during the day, while the nights are invariably cool. The iron-ore bearing area extends from the Iron Springs district to the Iron Mountain mining district, being approximately 25 miles long in a northeast-southwest direction, and from 1 to 3 miles wide in a northwest-southeast direction. In the Iron Springs and Pinto mining districts, the ore occurs at various points around three sides of Granite Mountain and Iron Mountain. This is readily understood by reference to Figs. 1-4. These mountains are composed of andesite, which has been forced up through the surrounding sedimentary formation, in the form of laccoliths. An extensive report on the geology of these districts was made by Leith and Harder,' who state: The three dominating geological features of the district are three large andesite laccoliths which constitute the Three Peaks, Granite Mountain, and Iron Mountain; lying in a northeast-southwest line across the area in question. Three unconformable sedimentary series, aggregating 4000 ft. in thickness, outcrop in successive rings around these laccoliths, dipping outward asymmetrically, very steeply at the contact, less steeply farther away. Still farther from the laccoliths, lava-flows 2000 ft. thick rest in nearly horizontal attitudes on the tilted sedimentary rocks. These general relations are modified by faulting. All of the rock formations of the district are more or less covered on the middle and lower slopes by unconsolidated and partly consolidated erosion debris, both aqueous and subaerial, which spreads out on the lower ground to make the deserts.

Jan 1, 1927

By Albert F. J. Bordeaux

(Cleveland Meeting, October, 1912.) THE immediate vicinity of the sea-shore, affording special facility for the exportation of ores, makes it possible to work certain mines in the Vladivostok district, which, in more remote places of Siberia, would remain unproductive. Outside of the city of Vladivostok the population is small and the country is very little prospected. Additional discoveries of valuable deposits like the large body of calamine which has recently been opened in the neighborhood of earlier worked lead-silver ores, in the Tetiuhe valley, are still in the field of possibilities. For many years gold alone was produced, in part from the coastal rivers and in part from a quartz-vein on Askold island near Vladivostok. But the production is diminishing, and prospectors are looking for other rivers in the interior, such as the tributaries of the Ussuri. These rivers are now more accessible than formerly, due to the slow but gradual development, of colonization by the Russian peasants. The few natives of the country, called Orodjones, are of the Chinese race. They resemble the North American Indian and are hardy fur-hunters. They have given some attention to placers and have already shown good specimens of gold-dust from the rivers Iman, Bikin, Noto, etc. Coal-mining was begun in the Vladivostok region more than 20 years ago, but in a somewhat irregular way. The industry is not as yet important and the best coal-seams are badly prospected, or ire even neglected. Copper, lead, and iron exist in several places. The amounts give some encouragement to the anticipation that the discoveries will give rise to important metallurgical works. I here present a review of the various deposits, based upon such safe information as is in hand, when I have not drawn upon my personal observations. Fig. 1 is a snap of Eastern Siberia, showing the mineral deposits.

Oct 1, 1912

By Donald K. Weaver

THERE have been eight different oil zones identified and produced at Santa Fe Springs, of which three or four are in turn divided into two or three parts. These zones are, from top to bottom, the Foix, difference of opinion over this nomenclature, with reference to the different zones referred to as Clark, it has no particular bearing on the water problems. Each of these oil zones has had waters of varying salinity associated with it, either within or at the bottom of the 'zone. Table 1 is a tabulation of the zones, their maximum thicknesses, salinity and heads of various waters. Surface waters are fresh, and of high head, giving artesian flow in some instances.

Jan 1, 1930

By G. W. Imholz

A number of interesting wells were drilled in north central Texas during 1940. The Shell Oil Company's Smith well in scc. 143, block I, H. and T. C. survey, Stonewall County, was completed for an initial production of 581 bbl. per day from the Mississippian limestone, with a total depth of 6065 ft. The same company's Patterson well, sec. 393, block D. H. and T. C. survey, Stonewall County, tested the Ellenburger limestone and was abandoned as a dry hole with a total depth of 6760 feet. In Nolan County the Tex-Harvey Oil Co. drilled a well in sec. 43, near the Tipton well, which was completed as a small producer in the Strawn section. The Tex-Harvey well tested this producing horizon but was abandoned as a dry hole with a total depth of 5210 feet. The Montour-Haggart well, sec. 184, block 2, H. and T. C. survey, Fisher County, tested the Strawn and was abandoned with a total depth of 5664 feet. The Georgian Oil Company's Blach, sec. 309, T. R. and L.. Shackelford County, encountered the top of the Ellenburger limestone at 4725 ft. After being plugged back to 3915 It. from a total depth of 4825 ft., the well tested 10 bbl, of oil per day and 300 bbl. of water. The W. I. Sothern No. 2 Carlisle well in sec. 293 was deepened to the Cambrian. The top of the Ellenburger was encountered at 6540 fcet. A wildcat well in Fisher County, the E. A. Stephenson-Maberry, apparently opened a new pool when the well encountered sand from 3298 lo 3302 ft. and was completed for 50 bbl. per day in the Cook sand horizon. In Jones County, the King Oil Company's Olsen well, sec. 158, B. B. B. and C. survey, extended the Avoca-Olander pool. The well was completed for 263 bbl. in 8 1/2 hr. from the Palo Pinto limestone, from 3298 to 3302 ft. Ungren-Frazier extended the Akard pool with No. I Akard, in the D. 'T. Bruce survey. The well was completed for 83 bbl. per day from the Cook sand, encountered from 2109 to 2126 feet.

Jan 1, 1941

By Felix Shay

THE Agua Fria mine is in eastern Honduras at Lat. 140° 06' N., Long. 86° 36' W. Danli, the seat of the local municipal government, is the nearest town. The property is approximately 44 miles east of Teguci-galpa, the terminus of a truck road from the Pacific coast. The mine lies at an altitude of 3300 ft. with surrounding elevations as high as 6000 feet. For 20 years the oxidized croppings of the Agua Fria vein had been worked intermittently when in 1927 an attempt was made to open the property. A shaft was sunk 300 ft. and considerable ore was blocked out, but before a mill could be installed financial difficulties arose and the mine reverted to the original owners. Erle P. Halliburton, of Los Angeles, purchased the property in 1934. At that time a careful consideration of all factors involved showed that air transport was the only practical method of moving the equipment and machinery necessary to commence production. The other alternative was by muleback, which required sectionalizing all equipment to a maximum load of 200 lb., and during the rainy season this type of freighting was subject to serious delays. It was decided to purchase a trimotor Ford powered by three Pratt and Whitney Wasp B motors developing 400 hp. each. There were several reasons for the choice: (1) this type of plane was available at a reasonable price, owing to its replacement by faster models on most of the airlines in the United States; (2) the ship was capable of carrying a pay load of 3000 lb. over the required distance; (3) since this airplane had been widely used there would be no difficulty in securing competent personnel or in purchasing spare parts. It was necessary to rebuild the plane for cargo service. The windows were removed and the fuselage was entirely covered. A hatch was cut in the top of the fuselage to receive heavy crane loads and pieces of freight that were too large or too long to go through the rear door. The seats were removed and the interior of the plane was lined with Duralumin sheets. A heavy-duty landing gear was installed and the floor was reinforced.

Jan 1, 1940

By G. W. Imholz

A number of interesting wells were drilled in north central Texas during 1940. The Shell Oil Company's Smith well in scc. 143, block I, H. and T. C. survey, Stonewall County, was completed for an initial production of 581 bbl. per day from the Mississippian limestone, with a total depth of 6065 ft. The same company's Patterson well, sec. 393, block D. H. and T. C. survey, Stonewall County, tested the Ellenburger limestone and was abandoned as a dry hole with a total depth of 6760 feet. In Nolan County the Tex-Harvey Oil Co. drilled a well in sec. 43, near the Tipton well, which was completed as a small producer in the Strawn section. The Tex-Harvey well tested this producing horizon but was abandoned as a dry hole with a total depth of 5210 feet. The Montour-Haggart well, sec. 184, block 2, H. and T. C. survey, Fisher County, tested the Strawn and was abandoned with a total depth of 5664 feet. The Georgian Oil Company's Blach, sec. 309, T. R. and L.. Shackelford County, encountered the top of the Ellenburger limestone at 4725 ft. After being plugged back to 3915 It. from a total depth of 4825 ft., the well tested 10 bbl, of oil per day and 300 bbl. of water. The W. I. Sothern No. 2 Carlisle well in sec. 293 was deepened to the Cambrian. The top of the Ellenburger was encountered at 6540 fcet. A wildcat well in Fisher County, the E. A. Stephenson-Maberry, apparently opened a new pool when the well encountered sand from 3298 lo 3302 ft. and was completed for 50 bbl. per day in the Cook sand horizon. In Jones County, the King Oil Company's Olsen well, sec. 158, B. B. B. and C. survey, extended the Avoca-Olander pool. The well was completed for 263 bbl. in 8 1/2 hr. from the Palo Pinto limestone, from 3298 to 3302 ft. Ungren-Frazier extended the Akard pool with No. I Akard, in the D. 'T. Bruce survey. The well was completed for 83 bbl. per day from the Cook sand, encountered from 2109 to 2126 feet.

Jan 1, 1941

By Frank A. Howard

WHAT are the reasons for the present public interest in the synthetic fuel industry, an interest which has culminated in the recommendation of the Secretary of the Interior that we start at once on a nine billion dollar program of construction? Three separate factors seem to have combined to create this pressure. First are recurrent seasonal and spot shortages of gasoline, fuel oil, and natural gas. Second is the international outlook, which forces us to face the possibility of war, with all that means in the way of increased call on our domestic resources and interference with our foreign commerce. The shortages we have experienced are superficially the result of lack of transportation, but basically they reflect a rapidly rising demand which has outstripped the expansion of productive facilities of all kinds. Not only oil and gas, but steel, coal, automobiles, and meat are temporarily in short supply for much the same reasons. The military problem has both long-range and short-range aspects, but the immediate necessity is to create reserve capacity in the United States to supply perhaps 2,000,000 barrels daily additional liquid fuel in time of war.

Jan 1, 1948

By E. F. Reed

CONSIDERABLE deep hole prospect drilling has been done in the last few years in the Globe-Miami mining district about 70 miles east of Phoenix, Arizona, and in the San Manuel-Tiger area about 50 miles south of the Globe-Miami region. More than 205,000 ft of churn drilling have been completed by the San Manuel Copper Corp. at their property in the Old Hat Mining District in southern Pinal County. The deepest hole on this property is 2850 ft; there are 49 holes deeper than 2000 ft. At the adjoining Houghton property of the Anaconda Copper Mining Co., where only one hole reached 2000-ft depth, there were 27,472 ft of churn drilling and 3436 ft of diamond drilling. Three churn drill holes were deepened by diamond drilling methods. Near Miami in the Globe-Miami district the Amico Mining Corp. drilled four holes by combined churn and rotary drilling methods, the total amounting to 13,879 ft, of which 2256 ft were drilled with a portable rotary rig. In the same district, besides doing a large amount of shallow prospect drilling, the Miami Copper Co. drilled two holes of 2560 and 3787 ft, respectively, which were completed by churn drilling methods. The rocks encountered in drilling at San Manuel and Tiger are described by Steele and Rubly in their paper on the San Manuel Prospect' and by Chapman in a report on the San Manuel Copper Deposit? The rocks are well-consolidated Gila conglomerate, quartz , monzonite, and monzonite porphyry. In some places these formations stand very well while being drilled, and three holes were drilled without casing, the deepest of which was 2200 ft. In other holes faulted and fractured ground made drilling difficult. In the Globe-Miami district the deep drilling was done in the down-faulted block of Gila conglomerate east of the Miami fault and in the underlying Pinal schist. The geology of this area is described by Ransome.3 In the Amico holes the conglomerate varied from material consisting entirely of granite boulders and fragments to a rock made up of schist fragments in a sandy matrix; in the Miami Copper Co. holes there were more granite boulders and the material was poorly consolidated. Drilling was much more difficult and expensive in the Miami area than in the San Manuel district, mainly because of the depth of the holes and the formations drilled. All the deep hole prospecting described in this paper was done with portable rigs. The churn drill rigs were of several types, of which the Bucyrus-Erie were the most popular. Bucyrus-Erie 28L, 29W, and 36L rigs were used on some of the deeper holes on the San Manuel property. A few Fort Worth spudder types were tried, and the deepest hole at San Manuel was drilled with a Fort Worth Jumbo H. The spudder type is considerably larger than most other rigs used on this work and required a larger location site. The spudders were belt-driven machines with separate power units, and time required for setting up and moving was much longer than with the more portable drills. All the churn drilling was done by contractors or with machinery leased from them. A few of the contractors had complete equipment, including most of the necessary fishing tools. Unusual and special, fishing tools were obtainable from the supply companies in the oil fields of New Mexico or in the Los Angeles area. Most of the contractors used equipment with standard API tool joints, so that much of it was interchangeable. Failure of tool joints is one of the principal causes of fishing jobs. It can be minimized if the joints are kept to the API specifications and the proper sized joints are used in the various holes. The minimum sizes that should be used with various bits are as follows: 12-in. and larger bits, 4x5-in. tool joints; 10-in. bits, 3 1/4x4 1/4-in. tool joints; 8-in. bits, 2 3/4x 3 3/4-in. tool joints; 6-in. bits, 2 1/4 x3 l/4 -in. tool joints; 4-in. bits, 1 5/8 x2 5/8-in. tool joints. Two rotary drill rigs were tried at San Manuel on the same hole, and a portable rotary drill rig was used on the Amico drilling for test coring the formation and for drilling in holes 3 and 4. Rotary drilling differs from churn drilling or cable tool drilling in that the bit is revolved by a string of drill pipe and the cuttings are removed from the hole by a thin solution of mud pumped through the drill pipe. The principal parts of a rotary rig are the power unit, a rotating table to revolve the drill pipe, hoists to raise and lower the pipe and to handle casing, and a pumping system to circulate the drilling liquid. The rig used on the Amico property at Miami was mounted on a truck. The larger rig used on the San Manuel property was hauled by several trucks and had separate turntable and pumping units. Diamond drill coring equipment was used successfully with the rotary rig in the holes on the Amico property, To allow for 2 3/8-in. drill pipe with tool joints, 3 1/2-in. core barrels and bits were used. With the standard 3 1/2-in. core barrel there was considerable difficulty in maintaining circulation with mud, so a barrel was designed with a smaller inner tube and a broad-faced bit. This allowed coarser material to circulate between the barrels. Rock bits of 5 5/8 to 3 7/8 in. were used with the rotary rig for drilling between core runs. Diamond drill equipment is much lighter than churn drill tools, so that fishing tools can usually be obtained from supply houses by air express when needed. Three churn drill holes on the Houghton property at Tiger were deepened by diamond drilling with Longyear UG Straitline gasoline-driven-machines. The open churn drill hole was cased with 2 1/2-in. black pipe. In deep hole churn drilling, casing is one of the most important items, especially in drilling in unconsolidated material like the formations drilled by

Jan 1, 1952

By Joseph Jensen

Recent developments related to petroleum engineering discussed in this paper are: 1. Drilling wells in with oil or the use of chemical compounds or (Imud solvents" for removing rotary mud from wells in order to increase or make possible oil production. 2. Comparison of results of electrical logging methods in locating water, as shown in a recent test on a well in the Los Angeles Basin. 3. A new method for logging formations through casing, known as the Stratagraph. Drilling Wells in with Oil or the Use of Chemical Compounds or Mud Solvents During the time that the California fields showed high gas pressures, the pressure of the gas within the formation was sufficiently great to break down the mud wall or cake formed while the well was drilling. That this did not always occur was demonstrated by the fact that in some of the older fields new wells sometimes had substantially higher initial productions than other wells near by. The explanation seemed to be that some sands were mudded off in the original drilling. Their pressure was then not great enough to break down the mud wall in competition with the higher pressure of the sands, but the situation reversed itself so that a later well benefited by the pressure in these originally weaker sands. As time passed, in wells deeper than 5000 ft. the difficulty of bringing wells on production became more pronounced. This led to a hunt for substitutes, of which a number have been tried. The one that has proved most successful in our experience at Ventura is known as the Nobs solvent. At well No. 1 of the Associated-Ventura Land & Water Co. when it was recompleted in February 1936, about 10 days were spent in trying to bring the well in in the regular manner, but only about 113 bbl. of water could be swabbed from the well, and even this quantity decreased as time passed. The Nobs solvent was spotted in the bottom of the hole opposite the perforations, inverted Guiberson swab rubbers were used on the drillpipe and the hole was down-swabbed in stages, beginning

Jan 1, 1937

By J. Quigley

As the outcrop mines in the West developed into underground operations, systems of ground support were gradually evolved. In the early coal mines there was little need for support except near the dirt line in portals, where stone masonry was common. Where the top was shaley or broken, native pine props with light cross bars and legs furnished enough support even in Utah's 25-ft coal seams. As depth of workings increased. roofs and backs of the same general nature as those near the surface became more and more unstable and required more and more support. Some coal airways show this tendency very clearly. From the surface down the same type of roof shows deterioration which an experienced eye can translate into a measure of depth under surface rather than change in rock characteristics. Rock bolts, developed by various companies and by the U. S. Bureau of Mines, have become an effective substitute for timber in sections of some metal and nonmetal mines formerly requiring escessive timber support, and further use of war surplus landing mats, chain link fencing, and a new punched channel developed by one of the steel companies has enabled other mines to operate deposits where costs of timber and lack of clearance for timber support would have prohibited mining. The block caving mines have made extensive use of reinforced concrete underground to achieve similar ends under difficult conditions. Steel sets are standard in many Bureau of Reclamation projects, although these are usually covered in with concrete to make the permanent structures the Bureau's reclamation projects require. But the use of steel in mining operations is limited and has been confined principally to the iron ore mines of Michigan, Wisconsin, and Minnesota. Some mines have installed used rail as posts, caps, and crossbars, but a rail section is not suited for load carrying, and used rails are generally brittle. having a tendency to fail without warning when overloaded. European mines were the first to reach the size of worked out areas and depths of cover resulting in major roof problems. The Europeans resorted to pack walls and masonry walls, in conjunction with timber arched sets. rail arches, and combination timber and rail and steel arches. The give in these pack walls and wooden blocking was supplemented by a hinge in the center of the arch. This design is called an articulated arch Through various refinements of this principle of the support giving graduallv with the load. Toussaint-Heintzmann developed the yielding or sliding arches, in which yield is accomplished by friction in the overlapping joints of the arch. This type has gained widespread acceptance in the Ruhr and Lorraine Basin and is being manufactured by Bethlehem Steel for sale in this country. In North America the anthracite mines in Pennsylvania, followed by certain iron ore mines in upper Michigan and Canada, were the first to employ these arches to any extent. The practice was later adopted by Kennecott at Ruth, Nev., and by others. Despite high initial cost, the use of these arches is growing in many parts of the country because of their suitability in heavy ground. In its present form of manufacture the yield-able arch consists of open U-shaped rolled section with heavy beads on the edge. The open edge of the U is placed toward the wall. The section nests in another section of the same dimensions, and an arch can be built up from rolled radii and tangents of various weights and lengths. Sections are fastened together by U bolts and saddles. The lap on the joint varies from 12 to 24 in., and ordinarily the bolts are tightened with a 1-in. drive air wrench. The arches are spaced with channel struts held by J bolts and saddles. Sections can also be obtained that are composed of various combinations of radii and tangents and true circles. The joints can be placed to bear against anticipated loads and asymmetrical loads imposed by dipping strata. In the arches now being manufactured clearance widths up to 19 ft are obtainable in weights of sections from 9 to 30 lb per ft. The circular cross sections are available in the same weights ranging from 8 to 16 ft diam. At present most of the arches sold are supplied only in carload lots. It is hoped that demand will grow so that distributors can stock various weights and sections to give small operators a chance to try this new type of rock support under their own particular conditions. Several excellent papers have discussed the properties of various sections now manufactured, the dimensions of the sets obtainable, and their application under widely differing conditions. The present article will describe the methods and results of a special use of the arches at Kaiser Steel mine No. 3. Sunnyside, Utah. Problem at Mine No. 3 : In 1953 Kaiser Steel Corp. laid out Sunnyside mine No. 3 to recover coking coal left by the previous operator, Utah Fuel Co.. below workings that had been abandoned in 1928. Two seams had been worked, the upper and lower, separated by 30 to 42 ft of rock. Approximately 10 million tons of coal had been extracted from this area some 3000 ft down the itch from the outcrop to a 1500-ft depth of cover. The mine had been opened by slopes in both upper and lower seams. Sometime in the late 1920's the lower slope

Jan 1, 1960

By John T. Ryan

DEFINITE improvement in its accident fatality rate in the coal-mining industry was recorded during 1941, based on preliminary figures for the period from January through October. Total production during this ten-month period was approximately 91 percent of the total production in all of 1940. The ten-month accident rate for both bituminous and anthracite mining in 1941 was 2.15 killed per million tons of coal mined, compared with a rate of 2.66 for the full year of 1940. The bituminous rate decreased from 2.55 in 1940 to 1.99 in ten months of 1941, and the anthracite rate from 3.62 to 3.53 in similar periods. The decrease is more apparent for the bituminous branch of the industry, as the high figure in 1940 was due to seven major disasters which brought death to 276 men. The same number of major explosions during ten months of 1941 caused only 64 lives to be lost. The severity of the explosions has been lower this year but a definite need still exists for reduction in this type of accident.

Jan 1, 1942

By Denis G. Maxwell

INTRODUCTION It is my intention in this paper to deal with gold, uranium, diamonds, platinum, manganese, chrome, vanadium and heavy mineral sands. These are the most important strategic minerals produced by the Republic of South Africa which are not covered in other sessions of this program. In each case I have high- lighted the statistics and peculiar advantages which combine to make South Africa a vital source of these minerals. Before proceeding to give individual attention to these minerals I believe it would be useful to define what I mean by 'strategic'. The Concise Oxford Dictionary defines strategic in the context of materials as 'essential for war'. However it is commonly used in a much broader sense than this (often, in fact, very loosely) and I prefer to define it as 'concerned with the acquisition and maintenance of power, whether economic, political or military.' A VITAL SOURCE In dealing with the individual minerals I have quoted statistics which are contained in Tables 1, 2 and 3. Table 1 clearly shows the absolute size of the South African mineral industry. However, it can also be used to demonstrate the importance of the industry to the South African economy if compared with the GNP in 1980 of about R60 billion. Table 4 illustrates clearly how important South Africa is as a supplier of these minerals to most of the important industrialized countries of the Western World. Gold If anyone had any doubts about the inclusion of gold in a list of strategic minerals I am sure that the above definition of 'strategic' will convince them that it certainly belongs there. Similarly no one is likely to have any doubt about the fact that South Africa is a vital source of supply. Tables 2 and 3 show that in 1980 we had 51% of the world's reserves and accounted for 55% of world production. The figures for the Western World are considerably higher. The only other major producer, of course, is Russia, with small but significant production in the Pacific Rim area coming from Australia, Canada, Latin America, Papua New Guinea, Philippines and the U.S. All South African mine gold production is shipped in bullion form containing about 88% gold and 9% silver to the Rand Refinery which is a modern refinery with large scale units capable of refining half a ton of bullion at a time. The Refinery is equipped to produce standard 'good delivery' gold as well as 9999 gold and 999 silver. The Refinery also produces the 22 karat blanks which are, used by the South African Mint to produce Kruger Rands. It goes without saying that the South African gold mining industry leads the world in all aspects of deep-level, narrow-reef mining technology. The industry's metallurgists, too, have a record of tenacious and continuing efforts to improve extraction to the level of the present finely honed efficient process used on all the modern mines. Uranium In 1980 South Africa had 14% of the uranium reserves of the Western World and accounted for 14% of production. In view of the paucity of data I am not in a position to estimate figures for the total world. All the other major sources of uranium in the Western World are situated around the Pacific Rim, with the U.S. and Canada already being major suppliers and accounting for 38% and 17% of Western World production in 1980. Australian production at the time was small but they have very large reserves and production is already rising rapidly. The U.S., Canada and Australia account respectively for 22%, 19% and 29% of the uranium reserves of the Western World. South Africa has been a major producer continuously for 30 years. Nearly all the uranium produced, amounting to about 115 000 tons up to the end of 1981, was a by-product or co-product of gold extraction. During that time the industry has frequently led the world in technological innovation, and has established a reputation as a reliable producer of a consistent, high-grade product. In the latter respect, it is helped by the fact that production is marketed by one company, Nuclear Fuels Corporation, which also blends, dries and calcines the product from the individual mines and samples and assays it before shipping. Diamonds Diamonds are the rock on which the South African mineral industry is founded. The discovery of diamonds in 1866 gave rise to the first major mineral industry in the country and the profits from diamond mining helped to finance the gold mining industry 20 years later. Although now overshadowed by gold, diamonds are still very important in the overall picture of mineral production and exports, as can be seen in Table 1. There are really three separate diamond markets - gem, natural industrial, and synthetic - and, to be meaningful, statistics should be provided separately. Unfortunately separate figures are not available. The figures in Tables 2 and 3 show that, for gem and natural industrial together, South Africa ranks third in the world in production and second in reserves. South Africa is a major producer of synthetics and probably ranks second in the world after the U.S. Recently, of course, Australia was the scene of a major diamond discovery and will soon become the only

Jan 1, 1982

By S. B. Sargent, V. J. Collins, Lester C. Uren

[The conclusions arrived at by authors in paper read before the Petroleum Division and the California Sections of the Americam Institute of Mining and MetallurgicaI Engineers and the Standardization Division of the American Petroleum Tnstitute, at a joint session held at Los Angeles, Cal., Jan. 21, 1926, are presented below.] From the theoretical discussion and experimental evidence presented in this paper, the following conclusions may be drawn: 1. The efficiency of the oil-well plunger pump is dependent to an important degree upon the submergence provided. 2. Ample submergence must be secured in order to provide sufficient static pressure to force the oil through the restrictions interposed in the oil path at the standing valve and at the plunger nut surrounding the garbutt rod. These restrictions should be no smaller than is structurally necessary, in order to reduce resistance to oil flow to a minimum. 3. A part of the static pressure developed below the standing valve by submerging the pump is dissipated in overcoming the inertia and in providing upward acceleration for oil left between the pump valves at the conclusion of the down-stroke of the plunger, and of oil below the standing valve in the gas anchor above the oil inlet. This loss in effective static pressure can be reduced to a minimum by dispensing with the garbutt rod and placing the working valve at the lower end of the plunger. The valves should be as near together at the conclusion of the down-stroke of the plunger as is consistent with security in avoiding striking of the lower end of the plunger on the standing-valve crown. Gas anchors should be short, and oil inlets should be as near the standing valve as is consistent with proper gas exclusion. 4. Because of the presence of gas in solution in the oil, which tends to escape from solution under the reduced pressure conditions above the standing valve, the effective length of stroke of the plunger is reduced, and the suction effect of the rising plunger is largely nullified. The influx of oil through the standing valve is therefore chiefly dependent on static pressure developed by submergence.

Jan 1, 1927

By Rudolph G. Wuerker

The progress made in testing the strength of rocks and minerals as they are encountered in mine operation is reviewed. An attempt is made to correlate these physical measurements with abrasive hardness, grindability, and behavior in comminution on one hand and fracture of rocks in pillars and roof control on the other. THIS paper reviews the progress made in testing the strength of rocks, ores, coal, salts, and other minerals as they are encountered in mine operations. It attempts to correlate the results of these physical measurements with technological properties more useful to the mining engineer: abrasive hardness, grindability, and behavior in comminution on one hand, and roof control, fracture of rocks in pillars, and mining methods with controlled caving on the other. In the following pages, the materials discussed will be referred to as rocks. Basic to rock mechanics and comminution are the problems of strength, elastic behavior, and failure, common to all brittle materials. A distinction will be drawn as to theoretical and applied research, and discussion of the progress made in each field will include test data obtained by the U.S. Bureau of Standards,1-1 the U.S. Bureau of Mines," the Iowa Engineering Experiment Station,"." the Committee on Geophysical Research at Harvard University,'" Basic Industries Research of the Allis-Chalmers Manufacturing Co.,11,12 by Philipps,13 and by Mueller," to name only a few. With refinements of testing methods and increased standardization. more useful and more comparable results have been achieved. This is especially important in testing a material like rock, as the inherent heterogeneity demands careful and exacting procedures. New measuring procedures that appear to supersede well known standard methods have contributed to faster and less costly testing yet have introduced new concepts, with implications as to comparability of results which must be watched. Reference is made to the sonic method for determining elastic properties," to be discussed in detail below. Basic Investigations Historically, all work in the field has started with the simplest determinations such as those for crushing strength, abrasive hardness, and grindability. These serve the limited objectives in the researcher's field of specialization: building construction, road ballast, roof control in mines, comminution, and seismic prospecting. Occasionally, fundamental properties like the modulus of elasticity E and Poisson's ratio v have been determined with the idea that they might have some bearing on the technological properties of the material under investigation. But it was not until the work of Philipps,13 of Harvard University,'" and of the U.S. Bureau of Mines"' that sufficient basic data were collected to allow researchers to go beyond the technological test and find the fundamental laws behind the behavior of rocks in mine and mill operations. The properties to be looked for are those that describe the elastic behavior of any material, the modulus of elasticity E and Poisson's ratio v being the ones determinable with least difficulties. Only two such properties are required to compute any other property such as the shear modulus, the modulus of rigidity, and the bulk modulus, all of which are related to each other according to well known equations of the theory of elasticity." In spite of their heterogeneous character, all rocks tested have possessed elastic properties. This does not mean that rocks of the same type always have the same modulus of elasticity, which varies exactly as the crushing strength or any other physical property of a rock can spread over a wide range. This has been explained by imperfections of the material always found in rocks, but to some extent this scattering of data is caused by inaccuracies inherent in the testing methods. Modulus of Resilience, a Criterion of Failure Increased availability of E values should allow us to test the validity of the quantity of strain energy theory which has been used in the solution of roof control problems by Philipps13 and by Holland.'" Recently Bond and Wang12 have applied this theory to explain the failure of an elastic material in comminution. Actually it is a very old theory, proposed as far back as 1885 by Beltrami.16 By its assumption the condition of yielding is determined by the term S2 M, = — x volume. Here M, is the modulus of 2E resilience, and its dimension is inch-pounds per cubic inch, that is, work per unit volume. Its numerical value is equal to the area under the stress-strain diagram. In the foregoing equation S is the yield stress (in psi) in tension or compression, whatever the case may be. E, the modulus of elasticity, is in psi. The great appeal of Beltrami's concept of stored energy lies in the fact that the two properties which seem to influence failure most, strength and elasticity, occur in the formula for the modulus of resilience. As an illustration of this, the moduli of resilience in compression of some typical materials tested by the U.S. Bureau of Mines" have been plotted in Fig. 1. The sample of concrete of conventional mix is shown only for the sake of comparison. Its determination was made in the Department of Mining and Metallurgical Engineering, University of Illinois. The values of the moduli of resilience of the various specimens in the plot are:

Jan 1, 1954

By R. P. King

The two-phase distributed-parameter kinetic model for flotation has been wed as the basis for a digital simulation of flotation plants of arbitrary configuration. Ores that contain any number of minerals can be handled. The effects of incomplete liberation and particle-size distribution are specifically allowed for. The simulator allows the investigation of variations in throughput and in the slurry density of the feed, and of variations in stage volumes and aeration rates. It can handle cell behavior even under conditions of hindered flotation. The requirements for data preparation are completely documented so that the computer program is suitable for general-purpose use. The program is written in Fortran. The output from the simulator consists of the complete material flows in the plant, as well as the grade, recovery, and particle-size distribution in each stream.

Jan 1, 1976

By LEWIS F. THOMAS

MINING geologists and mining engineer, rarely give due thought to the geography of mining deposits. They realize, it is true that what may be ore in one place would be only worthless rock in another because f the in accessibility of a smelter r a market; and they may consider the lack of a supply of labor, or water, or power to carry on operations. But they do not think (of these things in terms of geography. Geography may be defined as the science of relationships between earth and man, so geographers are vitally interested in the how and why of mining as it is carried on at different place, having entirely different environment-. Such environments are geographic complexes or composites of natural and cultural elements, which are listed and briefly discussed in the following paragraphs.

Jan 1, 1941

By C. V. Millikan

THE year 1930 in the petroleum industry has been characterized by the establishment of large potential production of crude oil. This has resulted in closer cooperation between companies by proration and unit operation agreements in order to afford an equitable outlet to all, and to prevent a flood of oil being forced on the market with attendant tremendous material and economic waste. Drilling wells in proved areas and wildcat wells are fewer than in the past several years. Restricted production and low prices have caused greater effort to increase producing and recovery efficiencies. Increased refinery efficiencies have amplified the effect of overproduction. Pipe line departments have been especially busy. New oil lines have reached more refineries by new and shorter routes. Establishing greater gas reserves by new fields has justified new gas lines to industrial centers, and has brought this fuel to thousands of new domestic consumers. Two long gasoline lines, a new venture in pipe lines, are being built to obtain a lower cost of transportation and less loss between the refineries and their distribution centers. The chairmen of the various divisions have discussed the developments of their respective branches more fully in the following reviews.

Jan 1, 1931

By Carle R. Hayward

THOUGH recent months have seen a rapid decline in lead-smelting activity and consequent uncertainty as to the future, the first half of the year showed progress in keeping with similar activity in other metals. Demand for scrap increased and various lead-bearing materials found their way to plants producing secondary lead. Some of these materials introduced complications into normal smelting procedure and were the cause of many conferences among plant officials attempting to find the most satisfactory method of treatment. If a blast furnace is to do itself justice it must be run with an open charge. Troubles inevitably result when materials are added to a charge which tighten it up and pre- vent free burning of the coke and con- sequent rapid smelting with a clean hearth This fact has long been recognized by plants producing primary lead, but only recently only it received the attention it deserves.

Jan 1, 1938