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By W. W. Adams, T. D. Lawrence, D. R. White

"This paper presents the results of the eleventh yearly accident-prevention contest, the National Safety Competition of 1935, conducted by the United States Bureau of Mines. Participating in the competition were 336 mines and Quarries in 37 States. Five mining or quarrying companies, each the leader in its group for having established the best safety record during the year, were awarded the national safety trophies 'Sentinels of Safety.Since these annual contests were begun 11 years ago the scope of the competition has been broadened materially, both as to the number of plants participating and as to the number of man-hours of exposure to accident hazards. Moreover, marked progress in the pre¬vention of accidents has been achieved, as is indicated by an almost constant downward course in the accident-frequency rates for the contest group as a whole during the past 11 years. On the other hand, the accident-severity rates for the group showed an upward trend during the first part of the period and a downward trend during the latter part, except in 1930 and 1934, when two disastrous explosions occurred with heavy loss of life, and in 1935, when there was an increase in the number of fatalities although no major disasters occurred. The accident rate for 1935, both as to frequency and severity, was higher than for 1934.The National Safety Competition is conducted by the Bureau of Mines in the interest of safety in the mining and quarrying industries. This object is accomplished directly through the efforts of the competing companies and their employees to win first place in the competition and thereupon receive well-merited and national recognition for their achievement. Indirectly the purpose of the contest is accomplished through studies by the Bureau of Mines of the fasts contained in the accident reports which the competing companies furnish to enable the Bureau to compute the accident rates that are the basis for determining the winners of the contest.The statistics that constitute the basis for determining the winning companies and the relative standing of all companies are prepared uniformly without regard to the States in which the companies operate, or to differences in classes of accidents covered by State laws relating to compensation for injuries resulting from industrial accidents."

Jul 1, 1936

By James M. Prudden, Jon C. Sprague

Valdez Creek Mining Co. properties consist of multiple intersecting paleo-placer channels containing appreciable quantities of coarse gold. Reverse circulation drilling, combined with geophysics, is used for both exploration and development reserve determination. Classical drill-blast-load-haul open pit mining techniques used for the 22,000 cubic yard per day production schedule required modification to compensate for arctic winter operating conditions. High wall stability problems within the glacial sediment overburden necessitated developing multiple dewatering methods and variable pit slope designs to eliminate unstable pit wall conditions. Processing mine run fluvial gravels utilized a classical winter protected screening plant-sluice box recovery system enjoying high metallurgical recoveries and zero discharge tailings disposal.

Jan 1, 1987

By F. Schreiter

The Ore Mountains in Germany have a history of more than 850 years of underground mining activity. This has created a situation where thousands of old mine shafts and adits are due for rehabilitation. While no long-term stable rehabilitation was executed in previous centuries, those abandoned mine sites which date back to the uranium mining boom from 1945 to 1962 were rehabilitated immediately after mine closure according to state-of-the art technology. Over the years, however, it has become obvious that most of these sites are not long-term stable and thus it has become necessary to rehabilitate them a second time. Technical University Bergakademie Freiberg is carrying out a research project on the optimization of this process. 70 mine site rehabilitation projects, the technology and the materials used have been assessed. A technical guideline for future rehabilitation projects, based on the outcomes of this assessment, is under development with the goal to make it easier, faster and more economical to select and apply suitable designs and construction materials for dams, plugs and other rehabilitation structures in former uranium mines.

Feb 27, 2013

By Ira B. Joralemon

The Ajo copper district is in the heart of the Arizona desert, near the western boundary of Pima county. Gila Bend, the nearest railroad point, is 43 miles north of the camp, and the little Mexican border town of Sonoita is 30 miles south. Between Gila Bend and Sonoita, Ajo is the only settlement save for one or two small cattle ranches and the uncertain villages of nomadic Papago families. The Little Ajo mountains rise a few hundred feet above wide desert valleys, beyond which are lava mesas. The camp itself lies at an elevation of about 1,900 ft. above sea level, in a little basin on the east side of the range, separated from the open desert by low hills. In the center of the basin the brilliantly iron and copper stained rocks of Copper mountain rise 150 ft. above the village. Many varieties of cactus and low desert bushes cover the hills, while in the large valleys there are clusters of mesquite, paloverde, and ironwood trees which furnish limited amounts of fairly good fuel. A scanty supply of water is obtained from wells in the desert and from- prospect pits in the camp. The nearest abundant source of water is the Gila river, 50 miles north of Ajo. (See Fig. 1.) , History of the Ajo District The Ajo, next to Senta Rite, New Mexico, is claimed to have been the first copper district in the Southwest worked by Americans. In the '60's or even earlier high-grade native copper and cuprite ore was mined from shallow surface workings and hauled by bull team 400 miles across the desert to San Diego. From there it was carried in sailing ships to Swansea, Wales. Later, the ore was hauled to Yuma, floated down the Colorado river to the Gulf of California, and shipped to Swansea. Bat-infested old workings and the massive axles of the bull carts are shown to prove the truth of the stories. From this early period until the beginning of the present century, the Ajo district was worked only in a casual and intermittent way. With the increased interest in copper mining during the past decade, the brilliant

Jan 1, 1915

By Arthur Miller

Most of the production of copper in the United States comes from a few large companies. Often overlooked, however, are the more numerous small mining operations, which collectively produce a significant portion of the nation's copper. The objective of this paper is to describe the operations of a small mining company - Ranchers Exploration and Development Corporation - how it views its place in this industry of giants, how it exploits the advantages offered by its relatively small size, and how it protects itself from the hazards being small introduces. Environment is, of course, a critical factor for such a company because it does not have the resources which help large companies weather periods of financial stress. Ideally, this environment is characterized by a heal thy economy, strong product demand, relatively stable prices , adequate grades and tonnages of ore commensurate with depth and over-burden, ready access to utilities, a dependable labor pool, and suitable technical "know how". When the environment is right, properties which were previously uneconomical to operate attract the attention of companies whose primary interest is a return on investment commensurate with risk over a reasonable period of time. Naturally, the amount of the investment and the duration of operation determines the size of the company which would be interested in such a venture. Such is the case with Ranchers Bluebird Mine at Miami, Arizona - a small property operated by a small company in a favorable economic environment.

Jan 1, 1967

By M. I. Al-Wakeel

Nile sediment was collected as a waste from one of the water treatment plants in Cairo, and subjected to petrographical investigation and granulometric, chemical, and mineralogical analyses. It was expected to find diatomite in that sediment but it was a surprise to find that the diatomite content amounted to about 52.01% by volume in addition to quartz, orthoclase and clay minerals. The latter are represented by montmorillonite and illite minerals. The sediment is light gray in color, soft and has low density and high surface area, such density and surface area generally decrease with temperature. The sediment absorbs 317% of its weight in water. The diatomite skeletons are the main factor responsible for its high porosity producing microporosity and low density, and these particles are concentrated in the very fine silt size fraction (11x2µm). The common diatoms in such sediment include Cyclotella ocellata Pant, and Melosira granulata (Ehr.) Ralfs. It seems that this Nile diatomaceous sediment has many advantages over the fossil diatomite, such as Fayium diatomite in Egypt, with the absence of carbonate minerals that require grinding and calcination those cause destruction of the cellular structure and energy consumption. This Nile diatomaceous sediment can be processed using sequential classification to obtain diatomite concentrate of 88.8% grade at 90.6% recovery, and a middling product of 19.4% grade and 5.8% recovery. The suggested flow sheet is quite simple to produce diatomite product for different industries at a low cost. The unusual particulate structure and chemical inertness make diatomite an ideal mineral to be used as functional filler in a wide range of industries, and as catalyst carriers and insulating material. Key words: Egypt, Nile sediment, Diatomite, Beneficiation, Sedimentation, Classification.

Jan 1, 2008

By Willard L. Cumings, Benjamin L. Miller

The Camaguey brown iron-ore deposit covers the top of Sari Felipe hill, the nearest point of which lies 14 miles NW. of the city of Camaguey. While there are several low flat-topped hills in the vicinity covered with a more or less continuous mantle of brown iron-ore, the deposit of San Felipe hill is the only one of any size and importance, and the name " San Belipe district" is proposed for the region. The deposit extends in a NW-SE. direction for a distance of about 10 miles, with an average width of 5 miles. The location is shown in Fig. 1, a sketch-map of the eastern part of Cuba. Fig. 2 is a map of the San Felipe district. 2. Description. The district is mentioned by Spencer,' who says: " The Cubitas iron-ore fields are situated from 12 to 15 miles north of Camagueg City, in the province of Camagueg.....Within an area measuring roughly 10 miles east and west and 4 miles north and south, there are several flat-topped mesas rising 300 to 400 ft. above the level of an almost featureless plain which extends for many miles in all directions except toward the north." With the exception of the discrepancy in his statements .as to the distance from Camaguey and the area of the hill, which is over 50 sq. miles, his description is a very good one. Kemp2 has the following to say of ores in Camaguey Province:

Jan 1, 1912

By G. R. Fitterer, E. A. Krockenberger, B. E. Sockman, R. B. Meneilly, J. F. Eckel, E. W. Marshall

"Steel manufacturers have noticed a decided tendency on the part of many of their customers to become more exacting in their steel specifications. Under these conditions, the steel must not only meet the specifications of physical properties (tensile strength, reduction of area, elongation, impact strength, grain size, normality, etc.) and the chemical analyses, but must also pass the inspection test of ""cleanliness.""By cleanliness is commonly meant the absence of oxide and sulphide inclusions. Other foreign particles such as furnace or ladle slag, ladle and runner brick, etc., must also be absent. The determination of cleanliness at present is usually made by microscopic inspection or macroetching.The rejection of steel for lack of cleanliness is increasing, out cleanliness is one of the most difficult requirements for the manufacturer to fill. The reason for this is that every steel inspector has a different conception of a. clean steel. A material which does not pass the examination of one inspector way be regarded as entirely satisfactory by the metallurgist of an¬other company. The cause of this confusion and disagreement concerning the definition of a clean or a dirty steel is simply that as yet no standardized procedure for the determination of impurities has been proposed and generally accepted, since many variables are encountered which interfere with the development of a satisfactory method. An idea of the complexity of this situation will be obtained from the following pages.A Survey of Proposed Analytical MethodsAlthough no analytical method has been accepted, many procedures have been proposed, as may be seen in Table 1. Therein are listed 16 of the better-known processes, pith references to the work of their originators, their mechanisms of determination, and their applicabilities. Among these is included the electrolytic method developed by one of the present authors, and some comparison between this and previously proposed procedures may be obtained by a study of the table. It appears that this new method Las many advantages over the others, and this paper presents a critical Study of its value."

May 1, 1933

By Sam Tour

OF the new alloys achieving commercial prominence during the year, an aluminum-silicon magnesium casting alloy, which is similar in many respects to the 4 per cent copper alloy, developed about 1921, which has attained such a wide field of service, may be mentioned. The new alloy, like the old, is a heat-treatable type and develops about the same physical properties. The alloy casts easily and is relatively insensitive to high pouring temperatures. Its ability to produce substantially leak- proof castings is noteworthy. A second casting alloy development is the new Aluminum Co. of America No. 132, "Lo-Ex" piston alloy, a result of nearly eight years of research. The alloy contains about 14 per cent silicon and varying amounts of nickel, copper, and magnesium. It exhibits a low coefficient of expansion and thus permits small piston clearances. Its lower specific gravity is a further advantage.

Jan 1, 1932

By Rogerio Castejón

The evolution on the computer in the last 10 years have caused a big change on the way the mining companies are doing exploration. The following factors have contributed to that change: the downgrade of computers and software cost associated with the “usability” (easy of use) of the present systems (remember the old DOS and UNIX systems). New systems are more focused on the users rather than on the experts in applications, meaning that the geologist must understand geology and not operational system, programming, etc. Market conditions requires exploration to be faster and more intelligent than in the “old” times, and companies are always demanding quicker answers from their geologist group as well as lower exploration budgets. Exploration teams must be more effective and efficient. In this sense, the only way to achieve those requirements is to use the proper techniques, methods and tools on the diverse stages of exploration. Its necessary to consider that the costs of data acquisition increase, almost exponentially, through the stages of exploration, from grass roots to advanced stage.

Aug 25, 2002

By G. R. Hopkins

For several years prior to about the middle of 1928 both the number and capacity of natural-gasoline plants showed a steady increase; this resulted from a material gain in the supply of casinghead has due to the discovery of a number of flush fields with relatively high gas-oil ratios. From 1928 to date some form of proration has been continually in force, with a consequent curtailment in the supply of wet gas. This decline in available gas and a severe decrease in prices, due largely to the increasing competition of light refinery products, has eliminated virtually all of the weaker units during the last 5 years, with the result that the number of plants declined from 1,155 on January 1, 1928 to 19035 on January 1, 1930, to 909 on January 1, 1932, and then to 859 on January 1, 1934, The struggle of the small high-cost producers to exist is illustrated further by the trend in the number of shut-down plants, which has increased from 36 on January 1, 1930 to 100 on January 1, 1932 and to 128 on January 1, 1934. The increase in the number of plants prior to 1929 resulted in a material gain in the total capacity, but the decline in number between 1929 and 1932 was not followed by a corresponding decrease in capacity, as gains resulting from the construction of a few very large plants overbalanced the loss due to the dismantling of a large number of small ones. However, the low prices of 1932 and 1933 supplied little incentive for new construction, and the total capacity declined in approximately the same ratio as the number. Thus the total capacity declined from 11,387,000 gallons daily on January 1, 1932 to 13,060,000 gallons daily on January 1, 1934, Of the latter 9,181,000 gallons (91 percent) represented the capacity of the operating plants and 679,000 gallons (9 percent) the capacity of the idle plants.

Jan 1, 1934

The whole of the iron ore required by the Broken Hill Proprietary Company Limited at the Newcastle Steel Works, and Australian Iron and Steel Limited, at Hoskins' Kembla Works, is drawn from the Iron Knob, Iron Monarch, Iron Prince and Iron Baron deposits situated in the northern part of Eyre's Peninsula, South Australia.The Iron Knob and Iron Monarch deposits are near the township of Iron Knob, approximately 42 miles W.S.W. of Port Augusta, whilst the Iron Prince and Iron Baron deposits are some 18 miles due south from Iron Knob, in another group of leases, the adjacent township being known as Iron Baron.The ore mined at Iron Knob, Iron Monarch, Iron Prince and Iron Baron is conveyed on the Company's 3ft. 6-in. gauge tramway to Whyalla, on the western side of Spencer's Gulf, approximately 45 miles south by west of Port Augusta whence it is shipped to Newcastle and Port Kembla.SHORT HISTORY.The establishment in South Australia of the lead smelting industry at Port Pirie, Dry Creek and Port Adelaide in the...

Jan 1, 1937

By J. P. Capp

The Bureau of Mines conducted field-scale experiments in underground gasification of coal with oxygen-enriched air. A path about 140 feet long was linked at the rate of LO feet per day through a coalbed hydraulically fractured with a mixture of starch gel and sand. During the best gasification period, which extended for 2-1/2 days, 785,000 std. c.f. per day of 124-B.t.u. gas was produced. In other periods the heating value at times was almost 300 B.t.u. per std, c.f,, but sustained production of such gas was not achieved. During gasification, a total of 50 tons of coal was gasified and 114 tons of coal was carbonized. Approximately 12 million B, t .u. per foot of nominal path was recovered at the surface.

Jan 1, 1962

By James Green

It has often been said that the best contracts written are by people who are suspicious of each other. The Spanish philosopher, Ortega y Gasset, said: "Every contract is an Act of Distrust." The arena for dispute settlement outside of the courts is increasing day by day - contracts, especially construction and civil engineering contracts, are written containing arbitration clauses for settling disputes - the very drafting of standard forms of contract, do in some instances by their very construction, create an ambiguity as to intent and provide a breeding ground for dispute. I come from a land far across the sea - the most southern land before the South Pole. Being a young country, 150 years old, we are still progressing - being far removed from the trouble free zones of the world and nuclear free we enjoy a lifestyle second to none.

Jan 1, 1987

By A D. Campbell, G R. Power

The increasing availability of marker data in sublevel caving operations is changing the way draw can be managed to achieve positive recovery outcomes in these mines. This paper describes how marker data has been incorporated into flow simulations to help calibrate full mine ore recovery simulations for the forecasting and optimisation of recovery.Some flow modelling techniques do not use marker data, relying instead on the outcomes of physical and numerical experiments to guide assumptions about an idealised recovery flow shape. Other mines have access to marker trial data, but find it difficult to specifically link this marker trial information to their recovery models. This can make it difficult to create a link between the marker trial information and recovery forecasting and limits the potential value of the marker trials at the mine.In the simulations shown here, the marker rings are fully incorporated into the flow model, and can be tracked in the model. The model is compared against the real underground marker recovery information to give the user an indication of how accurately the flow settings in the model are reflecting the conditions in the experimental marker rings. An example of use of this system at an operational mine is included.CITATION:Power, G R and Campbell, A D, 2016. Modelling of real-time marker data to improve operational recovery in sublevel caving mines, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 105–110 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By R. L. Lawson

I?ve been asked to appraise the global role of coal and mining, and the best place I can think of to begin is with the World watch Institute, which purports to monitor all things global. Last fall the institute?s magazine, entitled World Watch, in a cover story called for a worldwide campaign to outlaw the use of coal before this century?s end. To my mind the article began the campaign. However, the institute had to admit that no such ban will be possible unless there is special help and heavy intervention?that is, novel policies and punitive taxes. I?ll quote directly from the magazine to underscore the point: ?without them the market will continue to deceive us into thinking coal is cheap, abundant and irreplaceable?.

Jan 1, 2001

By Daryl R. Tweeton

This Bureau of Mines publication provides information to assist in selecting a lixiviant (leach solution) for in situ uranium leaching. The cost, advantages, and disadvantages of lixiviants currently used and proposed are presented. Laboratory and field tests are described, and applications of geochemical models are discussed. Environmental, economic, and technical factors should all be considered. Satisfying environmental regulations on restoring groundwater quality is becoming an overriding factor, favoring sodium bicarbonate or dissolved carbon dioxide over ammonium carbonate. The cheapest lixiviant is dissolved carbon dioxide, but it is not effective in all deposits. Technical factors include clay swelling by sodium, acid consumption by calcite, and the low solubility of oxygen in shallow deposits. Laboratory leaching tests can provide useful data. However, they can be misleading if, for example, the ore is allowed to oxidize before testing or if distilled water instead of formation water is used for making solutions for permeability tests. Geochemical models presently are more useful for indicating trends in solubility than in reliably predicting concentrations.

Jan 1, 1981

From 1999 to 2008 rock related accidents accounted for 75 fatalities, nearly 6,000 injuries and almost 14,000 incidents (Pappas and Mark, 2011). Clearly this shows that rock related safety on coal mines remains a serious issue and more effort is needed to address this hazard. This paper reviews support design considerations and monitoring needed to improve rock related safety in room and pillar coal mines in the USA. From the present study design considerations continue to evolve and improvements in technology and a better understanding of failure mechanisms and methods to prevent these failures from occurring are in place. At first glance, the design of safe and efficient underground openings appears simple until the designer begins to realize the complexities and variability of geometries, geology, loading and stress influences, support designs and other factors such as corrosion and economics. Ultimately the goal of all designs is to ensure that it can be completed safely, last for the duration of the design life and it is economically feasible.

Aug 1, 2013

By Herbert H. Einstein

This report contains the documentation for 11 computer programs representing the entire computer documentation for the eight-volume report entitled "Risk Analysis for Rock Slopes in Open Pit Mines." A detailed summary of the programs is included.

Jan 1, 1979

By T. Dlokweni

Several Rockmass classification systems have been developed and used in Civil Engineering design and for underground mining operations. Some of these rockmass classification systems have been modified and used in the South African coal mining industry to quantify descriptive geological information for use in coal mine design and roof support selection. The Coal Mine Roof Rating (CMRR) system developed in the USA has been investigated in detail as part of the study. Advantages and disadvantages of the system have been identified by means of underground and surface borehole testing. Investigations into the rating systems in South Africa found that most of the rating systems used in the South African coal mining industry are for planning purposes, and are conducted on borehole cores. This study also highlighted that the rating systems being used are based on geology, and that the human factor plays a major role in the rating systems. To overcome these problems, all the classification systems used in South African coal mines have been benchmarked against impact splitting technique and documented. The best elements of these systems are combined into a new standard system that will be easily used by all mine geologists and rock mechanics engineers. Plusieurs systèmes de classification de la masse rocheuse ont été développés et utilisés dans le Génie Civil et pour les opérations d'exploitation minière souterraine. Certains de ces systèmes de classification de la masse rocheuse ont été modifiés et utilisés dans l'industrie minière sud-africaine pour quantifier l'information géologique descriptive utilisée dans la conception de mines de charbon et la sélection de soutènement du toit. Le système d'Evaluation de Toit de Mine de Charbon (CMRR) développé aux USA a été examiné en détail, comme part de l'étude présente. Tests en surface de trous de mine ont permis d'identifier les avantages et inconvénients du système. Une étude des systèmes d'évaluation en Afrique du Sud a révélé que la plupart des systèmes d'évaluation utilisés dans l'industrie minière sud-africaine sont utilisés pour la planification, et sont menés sur les carottes de trous de mine. L'étude présente a aussi souligné que les systèmes d'évaluation utilisés sont basés sur la géologie, et que le facteur humain joue un rôle majeur dans les systèmes d'évaluation. Pour surmonter ces problèmes, tous les systèmes de classification utilisés en Afrique du Sud ont été référencés en termes de technique de fissuration sur choc, et documentés. Les meilleurs éléments de ces systèmes sont combinés dans un nouveau système standard qui sera utilisé aisément par tous les géologues de mine et les ingénieurs miniers. Verschiedene Gesteinsmassenklassifikationssysteme wurden entwickelt und kamen im Design für Hoch- und Tiefbau und Untertageabbau zum Einsatz. Einige dieser Gesteinsmassen-klassifikationssysteme wurden modifiziert und sind in der südafrikanischen Kohlebergbauindustrie in Verwendung, um beschreibende geologische Informationen für die Anwendung im Design von Kohlebergwerken und der Firstabstützungsauswahl quantitativ zu beschreiben. Das in den USA entwickelte Kohlengrubenfirstbewertungssystem (CMRR) wurde als Teil der Studie im Detail untersucht. Vorteile und Nachteile des Systems sind mittels der Untergrund- und Oberflächenbohrlochprüfung gekennzeichnet worden. Prüfungen der Bewertungssysteme in Südafrika ergaben, daß die meisten Bewertungssysteme die in der südafrikanischen Kohlebergbauindustrie benutzt werden, Planungszwecken dienen und werden anhand von Bohrlochkernen durchgeführt. Diese Studie hob auch hervor, daß die verwendeten Bewertungssysteme auf Geologie basieren und daß der menschliche Faktor eine Hauptrolle in den Bewertungssystemen spielt. Um diese Probleme zu überwinden, wurden alle in südafrikanischen Kohlengruben benutzte Klassifizierungssysteme vergleichsweise in Hinblick auf Spaltschlagtechnik überprüft und dokumentiert. Die besten Elemente dieser Systeme werden in ein neues Standardsystem kombiniert, das leicht von allen Grubengeologen und von Gebirgsmechanikingenieuren benutzt werden kann.

Jan 1, 2003