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By B. J. Kochanowsky

The idea of a portable crusher is not new. Many such crushers are available but they are small and designed for construction work. For many years the author has suggested, both in this country and in Europe, the building of larger portable crushers intended expressly for use in quarries or open pits. Although not applicable under all conditions, there are mining operations where a mobile crusher arrangement could be more profitable than the facilities now used. The primary use of a portable crusher, i.e., a crusher mounted on crawlers or tires, in the rock and mining industries is to reduce costs by permitting the substitution of conveyor belt haulage for truck or track haulage. The usual sequence of operations in surface mining is drilling, blasting, loading, haulage, and crushing. Haulage is normally accomplished by truck or track-mounted cars, the latter method being used for the longer distances. However, by using a portable crusher in the pit, the sequence of operations would be changed so that the crushing stage would occur before haulage (Fig. 1). Such a sequence would permit the use of conveyors to replace the more expensive truck or track haulage methods. Since most quarry and open pit operations normally require a crushing stage, the only additional costs incurred will be due to the investment required to purchase or construct a mobile arrangement for a crusher. But this factor has to be weighed against the advantages to be gained by conveyor haulage. As shown in Fig. 2, transportation of material by belt conveyor over short distances is less expensive than by truck. The inclination of the belt has no effect on belt speed; consequently, the hourly tonnage moved remains the same. Conversely, the output rate of trucks as expressed in tons or ton-miles per shift decreases proportionally to the haulage speed, which is considerably slowed by the steepness of the road (Fig. 3, left). Although maximum possible grades and maximum economic grades of haulage are greater for a belt than for a truck (over the same total lift), the longer haulage distances favor the use of trucks. Although power consumption for hauling on a grade increases for both conveyances, the rate of power consumption increases faster for trucks than for conveyor belts (Fig. 3, right). Since the output rate and related fixed costs are affected by the travel speed, total haulage costs with trucks would increase with the grade more rapidly than the similar costs of conveyor belts (Fig. 4). Travel distance, road grade, speed, size and number of pieces of equipment, efficiency of operation, and many other factors affect such haulage costs. In general terms it can be said that the shorter the distance, the steeper the grade, and the greater the output, the more advantageous the belt becomes in comparison to truck or track haulage. In addition to potential cost savings in haulage procedures, a portable crusher would allow better utilization and performance of shovels. Loading operations would not be interrupted as often by the necessity of waiting for cars or trucks. Unfortunately, the application of belts in open pits for haulage from bench sites is generally not practical under existing conditions because a belt fed directly by a mechanical shovel can be torn, damaged, or worn out quickly by the large rock fragments falling on it during loading. However, by using a mobile crusher this situation can be avoided. As shown in Fig. 1 (b), the shovel feeds rock into the crusher located behind it. The crushed material is initially transported by an extensible and/or movable belt, thence by a longer stationary conveyor to the plant where the material is subjected to further treatment by secondary crushing, screening, etc. The first-mentioned conveyor, needed to bridge the distance between the shovel and the stationary conveyor, is necessarily variable in length owing to the continuous movement of the shovel and the desire to keep the stationary belt at a safe distance from the bench during blasting operations. The remarkable part of mobile crusher operations is the extra-ordinarily high output per man-shift, the low maintenance and power requirements for haulage, and the increased output of the loading shovel. A cement quarry which has been using a portable crusher and conveyor since 1956 requires only three men to operate the shovel and crusher and to transport the crushed rock by belt from the quarry face to the screening plant. If truck haulage

Jan 1, 1961

By V. D. Perry

Mineralized breccia pipes, because of their widespread occurrence and close structural relations to some of the world's great ore bodies, are objects of unusual interest for mining engineers and geologists. The literature contains many references to them, but it is questionable whether their genetic significance and economic importance have been sufficiently emphasized. The purpose here is to stress these features, relating them to the field facts, for the particular benefit of younger generations of geologists who, confronted with and sometimes confused by the growing flood of geochemical, geophysical, and other specialized research approaches, may be reassured that mappable field relations remain a foremost guide to a better understanding of ore deposits. A mineralized breccia pipe is a pre-mineral, breccia structure which has controlled the circulation and deposition of subsequently introduced mineralization. It is composed of relatively rotated angular or rounded rock fragments, set in a mineralized matrix. A pipe in plan outline may be circular, oval or approach polygonal form, with a steep to vertical axis proportionately much greater than its horizontal dimensions. The pipe is a steeply plunging, chimneylike mass of brecciated rock cemented with later minerals. Rock breaks in a variety of ways and complete fragmentation often occurs without rotation of individual pieces. A finely broken rock mass may fit into a tight jig-saw pattern, each fragment having mutually concordant boundaries with its neighbors. The result is a stockwork of innumerable reticulating cracks that, once cemented by mineralization, forms a complicated intersecting network of individually insignificant but collectively important seams and veinlets. Stockwork fracturing among its many forms takes the shape of domes of subsidence, fracture pipes, and related peripheral zones around and over breccia columns, or a combination of any of these structures. The significance of the mineralized breccia pipe is that it represents the extreme or climactic expression of a structural type which has a variety of mutations including subsidence domes, fracture pipes, and other stockwork zones all with related ancestry and similar to dissimilar characteristics. These allied and associated structures hold an answer to the fundamental question of the origin of many important ore deposits. CANANEA-TYPE LOCALITY FOR BRECCIA PIPES The Cananea district is characterized by an unusual development of mineralized breccia pipes. It is an important copper producer located in Sonora, Mexico, a short distance southwest of Bisbee, Arizona, and at the southerly limit of the great porphyry copper belt of the southwestern U.S. Cananea's rocks consist of Paleozoic quartzite and limestone capped unconformably by a thick series of volcanics including andesitic flows, tuffs, and agglomerates. These rocks have been intruded by a deep-seated granite with related basic and acid differentiates including dikes and plugs of quartz mon-zonite porphyry. Mineralization coincides with a northwesterly trending belt of these intrusives which break upward into and through the sedimentary-volcanic rock sequence. The district has weakly defined tectonic alignments in a northwesterly direction with subordinate intersecting fracture elements, but lacks important faulting or fissuring to provide throughgoing avenues for the upward circulation of mineralizing fluids. Thus, as will be discussed in subsequent paragraphs, the alternate way in which late magmatic and hydro-thermal derivatives of the parent magma reached the near-surface zone was by excavating their own breccia pipe channelways. There are numerous stages of breccia pipe development, related both in time and space to magmatic activity. A compilation of similarities and differences in various pipes suggests that proximity or remoteness of a demonstrable or inferred magmatic source provides an orderly genetic basis for describing the following representative types. Cananea Duluth Type: There are no intrusive rocks within or close to the Cananea Duluth pipe; therefore, the existence of any deep-seated magma that may have been related to its formation must be inferred. The structure is an oval-shaped ring 1200 x 300 ft in plan dimensions, cutting steeply across low angle, bedded tuffs, and other volcanics; it has been developed by drill holes to a depth of 2000 ft below the surface. The ore follows the periphery of the pipe and is composed of intensely brecciated rock which is cemented by minor galena, sphalerite, chalcopyrite, quartz, carbonates, and adularia. There is a definite vertical zoning of sulfides with less galena, continuing sphalerite, and increasing chalcopyrite at deeper levels. Within the interior of the ore ring, the brecciation becomes progressively weaker and coarser, the whole indicating relatively gentle slumping with broken, thin tuff beds pre-

Jan 1, 1961

By AIME AIME

As already announced in the January Bulletin, this publication will be issued during the coming year monthly instead of bi-monthly as heretofore. Among other reasons for this change, it is desired to effect thereby the earlier transmission to members of important papers, lists of candidates for membership, and other items of timely information. Spokane Meeting and Excursions. Further details of the' 97th meeting of the Institute have been sent to members in the Circular of May 8, 1909. For, convenience of the members a summary of the additional in¬formation is here presented. A special train of Pullman cars will leave Chicago about September 15. This train will be side-tracked at all places visited, and the sleepers will be available for lodging and the dining-car for meals during the entire trip, except during the Yellowstone Park tour. The general. cost of the trip per member will be $300, which includes transportation, berth, and meals for the entire trip from Chicago back to Chicago, almost 6,000 miles, and the tour through Yellowstone Park, occupying in all about 30 days. Special accommodations on the train will be furnished at the following, rates

May 1, 1909

By C. R. Van Hise

Introduction.............29 The Three Zones of the Lithosphere ..30 Zone of fracture............31 Zone of flowage............ 31 Factors influencing depth at which flowage occurs.. 32 Zone of combined fracture and flowage.. 33 The Water-Content and Openings in Rocks....36 Condition of rater in the zone of fracture.. 36 The openings in rocks...........38 Size and number of openings..... 40 Ore-deposits derived from zone of fracture..45 The source of underground water......... . 47 The cause of the flowage of underground water..47 Belts of underground circulation.. 51 Upper belt of underground circulation.. 51 Lower belt of underground circulation.. .... .52 Capacity of water for work in the lower belt of underground circulation........... 53 Movementsof water in the lower belt of underground circulation. 54 The preferential use by water of large channels.. 60 Physico-Chemical Principles Controlling the Work of Under ground Waters..........62 Chemical action............63 Underground aqueous solutions..64 The relations of solution and temperature..... 65 The relations of solution and pressure..66 Precipitation........... 67 Precipitation by change in temperature..68 Precipitation by change in pressure..69 Precipitation by reactions between aqueous solutions.. . 69 Precipitation by reactions between liquid solutions and solids. 70 Precipitation by reactions between gases and solutions. and solids............71 The General Geological work of Underground Waters.. . 71 Division of the zone of fracture into a belt of weathering and a belt of cementation............72

Jan 1, 1901

By H. H. Reamer, B. H. Sage

Attempts have been made to predict the volumetric and phase behavior of naturally occurring hydrocarbon mix-turesl-6 but these methods have not been extended to the higher pressures and tem-peratures that are currently encountered in some producing formations. Furthermore, the methods of prediction at present avail-able have not been tested in a sufficient number of cases to ensure their applica-bility to all naturally occurring hydrocar-bon mixtures, even at the lower pressures and temperatures. For these reasons the behavior of a number of hydrocarbon mix-tures from a field in which the subsurface pressures are above 4500 lb. per sq. in.t and the temperatures are in the neighbor-hood of 250°F. was investigated. Method The objective of this program was to determine the volumetric behavior of ma-terial as it existed in the reservoir as a function of pressure, temperature and com-position. Strictly speaking, this cannot be accomplished in any simple fashion. How- ever, the variations in composition that are encountered within a producing reservoir may be approximated roughly by means of mixtures made up of two arbitrarily chosen constituents. Experience indicates that the liquid and gas phases from a high-pressure gas trap afford a simple source of material for this purpose. Throughout this discus-sion the samples of the gas phase and liquid phase from the production trap will be called the "trap-gas sample" and the "trap-liquid sample," respectively. The volumetric behavior of both of the trap samples was determined throughout the temperature interval between 100" and 250°F. at pressures up to 5000 lb. per sq. in. In addition, the behavior of eight different mixtures containing varying proportions of the two trap samples was studied throughout the same temperature and pressure intervals. The experimental results yielded information concerning the specific volume of the material as a function of pressure, temperature and the relative quantity of the trap samples. The relative amount of each of the paraffin hydrocarbons of lower molecular weight than n-hexane was determined for each of the trap samples. In addition, the specific weight, viscosity and average molecular weight of the hexanes-and-heavier fraction of the trap-liquid sample were determined as well as similar information for each of five fractions separated from this material by distillation. From these data the weight fractions of each of the components from methane through pentane were determined for the trap samples and eight systematically chosen mixtures. Materials The gas and liquid samples were obtained from the production trap of a well in the Rio Bravo field in California during the fall of 1939. Information concerning the condi- 70

Jan 1, 1941

By H. H. Reamer, B. H. Sage

Attempts have been made to predict the volumetric and phase behavior of naturally occurring hydrocarbon mix-turesl-6 but these methods have not been extended to the higher pressures and tem-peratures that are currently encountered in some producing formations. Furthermore, the methods of prediction at present avail-able have not been tested in a sufficient number of cases to ensure their applica-bility to all naturally occurring hydrocar-bon mixtures, even at the lower pressures and temperatures. For these reasons the behavior of a number of hydrocarbon mix-tures from a field in which the subsurface pressures are above 4500 lb. per sq. in.t and the temperatures are in the neighbor-hood of 250°F. was investigated. Method The objective of this program was to determine the volumetric behavior of ma-terial as it existed in the reservoir as a function of pressure, temperature and com-position. Strictly speaking, this cannot be accomplished in any simple fashion. How- ever, the variations in composition that are encountered within a producing reservoir may be approximated roughly by means of mixtures made up of two arbitrarily chosen constituents. Experience indicates that the liquid and gas phases from a high-pressure gas trap afford a simple source of material for this purpose. Throughout this discus-sion the samples of the gas phase and liquid phase from the production trap will be called the "trap-gas sample" and the "trap-liquid sample," respectively. The volumetric behavior of both of the trap samples was determined throughout the temperature interval between 100" and 250°F. at pressures up to 5000 lb. per sq. in. In addition, the behavior of eight different mixtures containing varying proportions of the two trap samples was studied throughout the same temperature and pressure intervals. The experimental results yielded information concerning the specific volume of the material as a function of pressure, temperature and the relative quantity of the trap samples. The relative amount of each of the paraffin hydrocarbons of lower molecular weight than n-hexane was determined for each of the trap samples. In addition, the specific weight, viscosity and average molecular weight of the hexanes-and-heavier fraction of the trap-liquid sample were determined as well as similar information for each of five fractions separated from this material by distillation. From these data the weight fractions of each of the components from methane through pentane were determined for the trap samples and eight systematically chosen mixtures. Materials The gas and liquid samples were obtained from the production trap of a well in the Rio Bravo field in California during the fall of 1939. Information concerning the condi- 70

Jan 1, 1941

By DIFTIGIHT E. WOODBRIDGE

(Glen Summit Meeting, June, 1911,) DURING April, May, and June, 1910, I was in charge of an examination of the greater part of the Moa iron-ore area in Oriente Province, Cuba, on the north coast, near the east end of the island. My instructions, on arrival at the properties, were to check former estimates of tonnages and grades, and to re-examine the ore comprised in claims covering 44,727 acres. This work included .the running of lines dividing the properties into co-ordinate planes, the boring of many thousand feet of holes spaced at the intersections of these co-ordinates, the taking of samples of the ore penetrated, the analysis of these samples for their various constituent minerals, and the determination of the results as to tonnages, depths, and grades, both for individual properties and for the entire group. Each section of every one of the thousand holes drilled was to be compensated for depth and grade with every other, a series of simple arithmetical calculations of no slight magnitude, the mere mechanical labor of which consumed much time, but finally resulted in giving a complete average of all the essential facts for the entire area of 18,000 hectares. Had it not been for the more than willing, active, and able co-operation of the officers of the Spanish-American Iron Co., from Charles F. Rand, President, and Jennings S. Cox, General Manager, down to the most humble water-carrier, the work would have consumed far more time than it did. Papers prepared by others, and to which my present paper may be considered an addendum, elucidate, more fully than I could hope to do, the origin and geological character of these ores. I will confine myself to the situation, method and expense of exploration, and to probable courses of development and mining, with some attention to the cost of the ore delivered in the United States.

Mar 1, 1911

By Chikao Nishiwaki

INTRODUCTION The Japanese dependency for mineral raw materials from foreign sources increased rapidly within the 20 years since the Korean war. During this 20 year period Japan has attempted to industrialize and develop her economy while depending mostly on heavy import of nearly all kinds of mineral raw materials. She has fabricated them using energy generated mostly by mineral fuel that are also imported. Fabricated goods are either used domestically to accelerate more fabrication industry or exported after adding more refinement or fabrication. In this paper iron ore as a major raw material for the Iron and Steel industry, three major base metals, copper, zinc and lead, and petroleum as a major energy source have been selected as examples to represent the general features of various kinds of mineral raw materials that are imported. Among other important mineral commodities for which Japan dependa upon foreign sources are: Aluminium, nickel and cobalt, potash and phosphorous 100 percent dependent and tin, tungusten, chromium and molybdenum over 95 percent dependent. IRON ORE Statistics for the important iron and steel raw materials, namely iron ore, coal and scrap iron are shown in Tables 1, 2 and Fig. 1. Iron ore is by far the most important and basic among these three commodities. There has been practically no steel or iron imported as a metal into Japan during this period. Iron ore, including aggregate such as pellets, and metallurgical coal are mostly transported in large ore cargo boats to the port where very efficient port facilities unload them directly at the steel mill site. As a result

Jan 1, 1976

By Fred C. Bond

JUST four years ago, in March, 1930, Gilbert LaBine discovered the rich deposit of pitchblende and silver ore on the east shore of Great Bear Lake, 30 -miles south of the Arctic Circle, which brought a new mining district into being. His original discovery is now the property of Eldorado Gold Mines, Ltd., but other groups have been active. Vigorous prospecting has outlined a mineralized zone that extends at least 100 miles from north to south. In this area silver discoveries have been relatively common; pitchblende, as might be expected, has been harder to find, though a deposit has been located this spring nearly 100 miles south of Eldorado that may be of great importance.

Jan 1, 1934

By A. C. Fieldner

THE total annual energy production from coal, petroleum, natural gas and water power has been increasing at a fairly constant rate during the thirty years ending in 1930. But since 1913 the demand for the competitors of coal has increased at a rate faster than that for coal. During the last twenty years, the curve of coal production has had a generally horizontal trend; in fact, the 1930 production of coal was six per cent less than that of 1913. Economists attribute this loss of demand to greater efficiency in coal utilization and to displacement of coal by oil and natural gas. These two factors are about equally responsible, and it is evident that research has been intimately concerned with both. About sixty per cent of the bituminous coal mined in the United States in 1929 was used for generating steam, either in stationary or locomotive boilers. A decade ago seventy per cent or more was used for this purpose. This change is due largely to tremendous advances in fuel economy.

Jan 1, 1933

By Wm. A. Haven

As soon as the likelihood of American participation in the war was established, and in spite of the fact that we can produce almost as much as all other countries combined, the demand for prompt deliveries of iron and steel products from American factories began to exceed their utmost capacity, and, after fifteen months of practically full operation, has continued to do so. Therefore, it would seem worth while to review some of the aspects of the supply and demand for steel as well as the efforts that are being made to bring them into balance. It is still being debated as to whether the situation should be defined as a real shortage that will persist through the emergency period or as a temporary one than can be relieved by less drastic measures than a Government-sponsored program of expanding existing plants and building new ones.

Jan 1, 1942

By Jay N. Fairbanks, Richard G. Robinson

This paper discusses a computer program and related formulas for fire fighting responses by coal mine personnel. The computer will interpret the mine air analysis, print reports, and provide relevant graphs allowing quick and accurate responses to coal mine fires.

Jan 1, 1983

By AIME AIME

FEW mining schools possess an art gallery and certainly none can equal the collection of paintings depicting the mineral industries now hanging in the comparatively new building of the School of Mineral Industries at The Pennsylvania State College. Dean Steidle, who conceived the idea, early this spring boasted of 55 paintings in the collection, by 24 different artists, the gallery being appraised at $18,000. Since then, eleven additional paintings have been added. Opportunity will he presented for an inspection at the meeting of the Industrial Minerals Division, to be held at the College, Sept. 24-26.

Jan 1, 1936

By H. A. J. Wilkens, H. B. C. Nitze

From time to time papers treating of specific cases of Southern gold-mines and mining have appeared in the Transactions of this Institute, as well as in other journals and publications. Mr. George I?. Becker, of the United States Geological Survey, made a reconnaissance of the Southern Appalachian gold-belt during the fall of 1894; the results of his investigations are published under the title of "A Reconnoissance of the GoldFields of the Southern Appalachians," in the Sixteenth Annual Report of the Director of the United States Geological Survey, 1894-95 : Part III., " Mineral Resources of the United States." Mr. Becker has treated the subject mainly in a scientific geological manner. We present this paper to the members of the Institute as requested by the Secretary last May, with the object of covering the ground from a more practical and technical standpoint. The notes for this paper were made in a large measure from personal observations, gained chiefly during the past summer on a trip through the field. In connection with this trip we collected a suite of typical hand-specimens, representing the gold-ores and wall-rock from the more important localities. This collection forms a part of the exhibit

Jan 1, 1896

THOSE NOT MARKED ARE MEMBERS; MARKED THUS t ARE ASSOCIATES. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. JUNIOR MEMBERS ARE MARKED II. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. AARONS, J. BOYD, Genl. Mgr., Chaffers G. M. Co., Boulder City, West. Australia. '05 ABADIE, EMILE R., Min. Engr Box 291, Porterville, Tulare Co., Cal. '76 ABBOTT, CLARENCE E., Genl. Supt., Iron Mines Div., 1405 Minnesota Ave., Bessemer, Ala. '04 ABBOTT, J. W., Min. Engr., "St. Omer," 123 N. Grand Ave., Los Angeles, Cal. '94 ABBOTT, Louis BENJAMIN, Chief Engr., Consolidation Coal Co., Elkhorn Div., Jenkins, Ky. '15 ABBOTT, ROBERT R., Met. Engr., Peerless Motor Car Co., Cleveland, Ohio. '12 ABE, ASAKA Yamagano G. M., Satsuma-Gori, Satsuma, Japan. '14 || ABRAHAMS, A. I., Student 1391 Madison Ave., New York, N. Y. '14 tACKER, E. O'C., Met Bethlehem Steel Co., Bethlehem, Pa. '86 ACKER, Louis K., JR., Min. Engr 565 Highland Place, Bellevue, Pa. '08 ADACHI, JINZOO 11 Shiba Park, Shiba-ku, Tokyo, Japan. '88 ADAMI, C. J., Min. Engr., St. Joseph and Doe Run Lead Companies, Bonne Terre, Mo. '12

Jan 1, 1917

By John V. Beall

Let's start at the beginning, Mr. Turner. Where and when were you born? In Lansing, Mich., on July 31, 1880. And what was your education? I went to the University of Michigan, where I got an A.B. degree in 1902; then to the Michigan College of Mines at Houghton, graduating from there in 1904 with a B.S. and an E.M. What was your first job in the mining industry, Mr. Turner, and what were you paid? In the summer of 1902, 1 was a field assistant for the U. S. Geological Survey in southwestern Idaho and southeastern Oregon, working under Israel C. Russell, professor of geology at the University of Michigan, who incidentally, had just returned from an expedition to study the effects of the eruption of Mt. Pelee, on Martinique. I was paid $60 a month and found; in addition to doing geologic and hydrographic work, I cooked many of the meals for a party of four, and wrangled four horses. I slept for four months under the stars, without a tent.

Jan 1, 1949

By Kenneth K. Humphreys, Joseph W. Leonard, Robert L. Llewellyn, William C. McCulloch

INTRODUCTION The particular field of application of machines utilizing air currents as the primary separating medium is in the cleaning of the fine sizes of bituminous coal. Approximately 25,400,000 tons of bituminous coal were cleaned by air machines during 1965. They have not found any application for cleaning anthracite. Since the development and introduction of the first successful commercial pneumatic oscillating machine for cleaning bituminous coal in 19 16, by the Sutton, Steele and Steele Co, Dallas, Texas, and the American Coal Cleaning Corporation, formerly of Welch, W. Va., seven other successful pneumatic coal-cleaning machines have been developed and introduced to the American coal-mining industry: 1. Peale Davis: "Pneumo-Gravity" machine. 2. Arms "Concentrator," oscillating table. 3. Hey1 and Patterson oscillating table. 4. "Stump Air-Flow," pulsating air jig. 5. "Super Airflow," pulsating air jig. 6. Ridge air jig. 7. Phillip air jig. While not all coals can be beneficiated by air washing, the air washing of coals that are easy to clean can be readily proved advantageous. Of all the preparation methods, pneumatic cleaning is the most acceptable from the standpoint of delivered Btu cost. This is based on the premise that a percent of moisture is just as detrimental as a percent of ash. The principle of dry concentration has never been determined with scientific accuracy. To the present time the study has been more of an art than a science. It is possible to forecast the results of wet concentration from a study of the washability characteristics of the raw coal but only after applying rule-of-thumb methods of interpretation to the specific gravity and size distribution can it be ascertained that the raw coal is amenable to dry concentration. Air as a separating medium dates back to biblical times as exemplified in the winnowing of chaff from the grain. However, the same application of air to coal serves merely to blow the dust away and size the remaining particles. Pulsating air was the solution to the problem and largely eliminated the necessity for close screen sizing which was required on early separators. Because of the low density of air, a medium of sufficient density has to be built with the material itself. Hence there must be some device to impart to the bed the necessary mobility for proper classification. Also, the

Jan 1, 1968

By John T., Ryan

THE subject assigned me, "Safety in Mining," is a very broad one and only the high spots can be covered in this short paper. As this is a meeting of the Coal Division, these remarks will be directed largely to coal mine safety, although the principles of safety and effective accident prevention methods are relatively the same in every branch of mining or industrial work. The coal mining industry should take pride in the part it has played in the development of the accident prevention movement, and there is ample proof for the statement that the first real organized accident prevention, work, both abroad and in this country, was con- ducted in the coal mining industry.

Jan 1, 1930

By John T. Cumberlidge, Frederic M. Chace

Nickel-bearing saprolite developed during the early Tertiary over a northeast trending ultramafic body of Jurassic age near Riddle in southwestern Oregon. The principal nickel mineral is garnierite, but other complex nickel minerals may be present. There are two main ore bodies, an upper (older) one associated with the Klamath peneplain, and a lower (younger) one on the Sherwood peneplain. Saprolite constitutes the bulk of the ore and was probably derived from peridotite and dunite through chemical decomposition by downward percolating meteoric groundwater. Decomposition took place by net loss of MgO, SiO2, and Fe without a change in volume. Faults and joints provided permeable zones which localized saprolite development, and faulting may have helped preserve some ore from loss by erosion. Garnierite-chalcedony boxwork ore was deposited by meteoric groundwater along faults, joints, and at the level of former water tables. Boxwork ore is entirely supergene, the chemical constituents having been derived from higher in the soil profile. The saprolites show evidence of both supergene and residual enrichment in nickel. Red and yellow soil occurs as a capping over saprolite and boxwork, and was derived from them by chemical and mechanical decomposition. The present deposits are probably truncated remnants of a formerly thicker and much more extensive deposit which probably included laterite at the surface. The deposits started to form in the early Tertiary due to deep chemical weathering under sub-tropical to warmtemperature conditions. Early Tertiary ero~ion surfaces of low relief probably contributed to the predominance of chemical weathering over mechanical erosion. Alteration under present climatic conditions favors the formation of soil from saprolite rather than the formation of new saprolite from peridotite.

Jan 1, 1968

By Wayne E. Tuomi

The mining industry is faced with a pressing problem; that is, to develop more efficient methods of extraction, handling and upgrading-techniques that will do the job faster and better than ever before. New techniques require new machines, or applications of new and improved materials that can be used to modify and improve existing machine and equipment designs. The traditional approach has been to increase productivity by increasing equipment size. Prognostication indicates that the trend toward larger equipment sizes and capacities will continue as one answer to the challenge imposed by future increases in mineral demands. But what is the limit on the continued growth of equipment size? Until about 1930, there was a very definite limit-a limit imposed by the strength of the steels and the power plants then available. The equipment engineer had come to an impasse: even though it was easily possible, for instance, to triple the size of a bucket, it had become impractical to correspondingly enlarge the boom, the counterweight, and the power plant.

Jan 3, 1967