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By J. Keith Seidler, David R. Lentz, Douglas C. Hall, Nicholas Susak

Abstract - The Ta-Nb-Zr-REE-rich McKeel Lake alkali granite pegmatite-aplite dike swarm is hosted within the late Silurian multiphase alkali granite intrusion (Welsford) near Browns Flats in southwestern New Brunswick. A steep easterly dipping series of pegmatite-aplite dikes trending 170º can be traced 150 m along strike; they are up to 40 cm wide, closely spaced (10-20 cm apart), and interconnected by narrow branching dikelets that generally trend perpendicular to the overall strike direction. The Welsford intrusion has mantle A-type affinities characterized by enrichment of Zr, Ta, Nb, Th, and rare earth elements (REE). Two separate sets of dikes have been identified: (1) an unmineralized fine-grained porphyry, which occurs at depth and seems to be the youngest intrusive phase; and (2) a mineralized pegmatite-aplite dike swarm (419 ± 20 Ma) that crops out at surface. The mineralized pegmatite-aplite dikes likely represent a late magmatic, highly fractionated phase of the Welsford intrusion. XRF and INAA data indicate that the Welsford intrusions and related pegmatite-aplite dikes show elevated levels of Ta (74-220 ppm), Nb (750-3,040 ppm), Zr (1,450-36,000 ppm), Y (540-3,070 ppm), Th (170-870 ppm), U (60-250 ppm), Ce (430-1,950 ppm) and Yb (110-290 ppm). Electron microprobe analysis of two samples identified Ta-Nb- and REE-rich phases: euxenite, fergusonite, aeschynite, (Y)-aeschynite, and a REE carbonate.

Jan 1, 2005

By Chiranjibi Santi, Amit Kumar Gorai, VIVEK KUMAR HIMANSHU

Air overpressure (AOp) and peak particle velocity (PPV) are the most undesirable effects of blasting in mines. It is an urgent need to design a predictor model for AOp and PPV for universal applications to minimize environmental effects and damages that occur due to blasting. The present study attempts to design an artificial neural network (ANN) model for the prediction of AOp and PPV in different conditions. In this study, the blast design parameters (number of holes, depth of the blast hole, stemming length, spacing, burden, distance of vibration monitoring location from the blast site, charge weight per delay) of two active mines (coal and iron ore) are considered in four different conditions for training and testing of the model for the prediction of AOp and PPV. The model was trained and tested in four different combinations of data (trained using data of one mine and tested using data of another mine, trained and tested using data of coal mine, trained and tested using data of an iron ore mine, trained and tested using combined data of both the mines) for examining the applicability in different conditions. The results indicate that R2 values are ranged from 0.886 to 0.908 and 0.8728 to 0.8959, respectively, in the prediction of PPV and AOp. A comparative study of the performances of the developed model with the other empirical model is also demonstrated. For this, the site constants of different empirical models were estimated individually for both the mines. The study results indicated that the ANN model performs much better than all the empirical models. It can be inferred from the results that blast vibration cannot be accurately predicted only from charge per delay and distance from the blast hole. The ANN model was considered many other factors and thus can predict the vibration level more accurately.

Jul 30, 2021

By Peter Grandstone, D. A. Jessup, D. B. Taliaferro

"INTRODUCTION Water flooding of oil sands in Texas as a means of secondary recovery of oil has been practiced mainly in the north-central part of the State, which includes the old shallow fields in eight counties, extending south through Wichita and Clay Counties on the Red River into Brown County.The Texas Railroad Commission, is empowered ""to promote conservation and prevent waste in the drilling, completion, operation, and abandonment of oil wells"" and ""to issue regulations necessary for fulfillment of these ends,"" granted The Texas Co. the first permit to inject water into the oil-bearing sand on December 7, 1935. The permit was granted after the Commission had conducted a number of hearings, which were attended by many operators interested in that method of secondary recovery. Through December 31, 1944, the Commission had granted 50 permits for water flooding. Of that number, 45 permits were issued for projects in north Texas, the remaining 14 being distributed throughout west and south Texas. By the end of 1944, there were 33 active and 5 abandoned water-flooding projects in the North Texas area, as is in figure I.Oil production in the North Texas area started in 1904 from the shallow sands (ranging from 100 feet to 800 feet in depth) of the Petrolia (or Henrietta) field in northern Clay County. Development was rapid and unrestricted during the boom period from about 1911 to 1918, and considerable waste of both produced oil and reservoir energy resulted."

Jul 1, 1946

By G. X. Zeng

A calculation programme of finite element method has been developed in order to study the behavior of excavation with sheet piling in soft clay. Based on a series of isotropically consolidated-undrained tests (CIU) on Hangzhou clay a linear relationship between the normalized initial tangent modulus number, E1, and stress-path parameter, a, is found for four different stress paths, and stress-path dependent modulus equations derived. Meanwhile, several influence factors, such as embedment depth and stiffness of the wall and soil conditions, were taken into consideration in the programme. Some valuable conclusions were obtained. Finally, a case history was studied by the proposed method of calculation. The result of calculation and the field observation are in good agreement.

Jan 1, 2010

By R. Biss

"Niobium or columbium, as usually called in North America is becoming a more and more important metal in the industrial world because of its attractive properties.Eventhough discovered in the early nineteenth century, it was not until the 1930's that its use became more widespread. The discovery of large commercial deposits in the late 1950's and the demand of industry for steel with high strength and toughness further promoted its use. To assure its adequate supply new or-e processinr technologies had to be developed. So, beside the traditional gravity concentration, the flotation process was employed for the partial upgrading of pyrochlore concentrate at S8ve (Norway) plant in 1953. The flotation process was equally used at St-Lawrence Columbium plant in the province of Quebec, Canada. The new plants at Araxa and Catalao in Brazil and at St-Honore, Canada, which supply almost of all niobium used today in the non-Communist world, also adopted the flotation process. The processes using long chain aliphatic rnonoarnines, diamines or sulfonates as collectors proved to be difficult especially on weathered types of ores or on those having a substantial content of silicate gangue minerals. They almost completely failed in case of alkaline intrusive rocks as syenites, nepheline syenite, ijolites and pyroxenites, composed almost entirely of silicate minerals. A lot of effort was devoted all around the world on research of new, more efficient flotation processes. So in 1982, Les Services T.M.G. Inc. (Niobec), sole producer of pyrochlore concentrate in North America, developed the direct pyrochlore flotation process from carbonatites. In 1983, at about the same time, the Quebec Department of Natural Resources Laboratories and Les Services T.M.G. Inc. announced a successful recovery of niobium Minera1s from a low grade nenheline syenite ore."

Jan 1, 1984

By M. Ahrens, J. Gonser

Gearless mill drives are a well established solution for grinding applications in the minerals and mining industries. The paper describes the functionality and technical features of such drive systems as well as their advantages compared to other drive solutions. Due to the variable speed operation the grinding process can be optimized for ores with varying grinding properties. This leads to significant optimization potential for the plant design as well as for its operation. Furthermore, energy and cost savings due to optimized operation, high system efficiency and high system availability are shown.

Jan 1, 2007

By K. Grubaugh

Ghana’s physiographic and geologic features are the basis for its long mining history. The Gold Coast colony has been a significant producer of gold. The gold of the Akan forest (Ghana) was a terminus for caravans that plied Saharan trade routes. Now it also produces significant quantities of manganese, bauxite, and diamonds In addition, the country produces kaolinite, silica for glass, salt, and both aggregate and dimensioned stone. Most secondary minerals are consumed locally but some amounts do find international markets. Ghana revised the mining laws and regulations in 1986. These revised laws dramatically increased gold production and improved the country’s economy. The success of these laws spawned imitators in other African states such as Cote d’Ivoire, Mali, and Burkina Faso. Representatives of these countries claim Ghana was their model. Environmental regulations exist but an intensive adversarial atmosphere is lacking. Ghana has also offered the mining industry incentives like accelerated depreciation rates and exemption from import duties on related supplies and capital equipment. The country has also pursued an aggressive policy to restore the nation’s business infrastructure.

Jan 1, 2001

By David R. Wilburn

The U.S. Bureau of Mines investigated the resources, costs, capacities, market relationships, and short-and long-term supply of bauxite, alumina, and aluminum. The 45 evaluated mines and deposits in 14 market economy countries (MEC's) have a demonstrated resource of 8.4 billion mt of bauxite and an aluminum content of approximately 2.1 billion mt. Developed world bauxite resources and existing primary aluminum smelting and refining capacity are sufficient to satisfy demand through at least 1995, when additional properties (with higher cost levels) would need to be developed to satisfy future demand levels. It is anticipated that new alumina or aluminum production most likely would occur in developing regions with large bauxite potential, low-cost energy sources, and a close proximity to refining and/or smelting capacity. An increase in aluminum recycling capacity would help meet future demand increases. A series of network model supply analyses was performed for the period 1988 through 2000. Based on announced future production levels and assuming demand grows at the level outlined in the analyses, model results indicate there is sufficient material available to meet demand until 1998, where-upon an aluminum shortfall is projected. Additional analyses investigated the effect of a reduced growth rate of demand and regional production variations in Venezuela on the international aluminum industry.

Jan 1, 1993

By Oliver Bowles

"Asbestos" is a name applied to a group of naturally fibrous minerals. Because it has the fibrous characteristics of silk or cotton and at the same time will not burn and has other advantageous properties as well, asbestos has specialized uses for which no adequate substitutes are yet available. Asbestos furnishes a major raw material for a great variety of essential products, the manufacture of which constitutes a vast industry. Asbestos generally occurs in irregular veins scattered throughout rock masses. Most of the fiber-bearing rock is mined in huge open-pit or underground workings. The fibers are separated from the rock and sorted into groups, according to length, in large, complex mills. The longer fibers are stripped to textile plants, where they are further fiberized and prepared in special machines and are used for spinning into yarn and weaving into unburnable cloth that has many important uses. The shorter fibers, which are much more abundant than the long ones, are used in asbestos-cement building materials in heat-insulating products and for a multitude of other applications. These processes and uses are covered in considerable detail in later sections of this report.

Jan 1, 1959

By E. H. BURROUCHS

This bulletin is the third of the series of yearly petroleum bibliographies being published by the Bureau of Mines. The two preceding, Bulletin 149 and Bulletin 165, were for the years 1915 and 1916, respectively. In arranging the references the same general scheme has been followed, but as in those bulletins, several changes and additions have been made in the classifica.tion, the more important being in the classes " Development and production " and "Refining and refineries." German periodicals for 1917 were not procurable and references to articles in those and in other foreign journals that were not available have been credited to the sources from which they were procured.

Jan 1, 1920

The Metallurgical Development of an Enargite-Bearing Deposit

Sep 13, 2010

By Jilai Xue

Industrial wastes containing 30-50 wt.% Al2O3 and 40-60 wt.% SiO2 may serve as an alternative resource for producing Al-Si alloys. Various raw materials such as used refractory materials from metallurgical furnaces, coal fly ash, andalusite residues, and so on were tested in laboratory to produce Al-Si alloys using carbon-thermal reduction process. A mixture of anthracite and petroleum coke was used as reducing agent. One of the most important operations was to prepare the briquettes made of different raw materials with varying contents of Al2O3 and SiO2. The effects of briquette property, A/S ratio (mass ratio of Al2O3 and SiO2), the amount of carbon reducing agent, on the reduction process and the resulting metals were investigated. The results are useful for development of an alternative technology for Al-Si alloy production, which has the potential application in recycling metals from industrial wastes containing Al2O3 and SiO2.

Jan 1, 2010

By Mark S. Sanders

There is a growing awareness among mining professionals that the human factor plays a significant role in safety and productivity. Since the 1960's, the science of human factors, or ergonomics, has been making inroads into the mining industry, and a considerable amount of research has documented human-factor-related mining problems and solutions. This Bureau of Mines report is directed toward summarizing the application of human factors to improving safety, productivity, and the general physical and psychological working conditions of miners. The aim of this report is to familiarize the readers with the role of human factors in the mining industry and the benefits that can accrue by systematically applying available human factors principles and data. The text contains 10 chapters dealing with human, equipment, and environmental factors. Each chapter builds on the previous chapter; therefore, it is recommended that the chapters be read sequentially However, if the report is used as a supplemental text, say in a mining safety course, chapters can be assigned in any order to supplement other readings.

Jan 1, 1988

By C. C. Blade

"This report on the properties of motor fuels sold through service stations ni the Unietd States is a continuation of a series of reports made in accordance with a cooperating agreement between the Coordinating Fuel Research (CRF) Committee of the Coordinating Research Council (CRC)3/ and the Bureau of Mines of the United States Department of the Interior. The first of these reports presented data on motor gasolines sold during the winter of 1935-36.4/ Further reports were issued describing motor gasolines sold during the succeeding summers and winters to and including the summer of 1941.4/ No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43, the semiannual reports were resumed.4/The present report presents analytical data for 1,381 samples, representing the products of approximately 75 companies. Most of the samples represented in this report were secured during July and the first half of August, 1945. As in previous surveys, the companies covered by the survey include both large and small suppliers. Conforming to former reports, the data cover three groups of samples – regular-price, premium-price, and third-grade gasolines.As the number of analyses submitted for samples of third-grade gasoline are not considered adequate to represent this type of motor fuel, data for the analyses have not been averaged, but the individual items are tabulated. The number of samples, items and brands comprising each group is as follows: Regular-price, 733 samples, 229 items, and 57 brands; premium-price, 504 samples, 197 items, and 56 brands; third-grade, 84 samples, 28 items and 12 brands. The meanings of these terms as sued in the surveys are as follows:"

Jan 1, 1946

By C. Q. Cupps

n view of increased interest in secondary recovery of oil in the Cut Bank field, Montana, a review has been made of unpublished data obtained during a 1943-44 study of reservoir oil characteristics in this field. Considerable uncertainty was attached to interpretations of subsurface oil sample analyses from six Cut Bank zone wells, one Lander sand well, and one Moulton sand well, because of adverse sampling conditions and wide range in the data. Much of this uncertainty has been removed by this review which has shown two of the Cut Bank zone samples and the Moulton sand sample to be representative of the reservoir oils. Estimates of original reservoir oil characteristics derived from differential-liberation analyses of these samples show that the oil in the Cut Bank zone was initially saturated at the gas-oil contact pres-sure, 750 psia, and the oil in the Moulton sand was undersaturated with a saturation pressure of only 380 psia. The rest of the samples were indicated to be nonrepresentative of the reservoir oils because of a disproportional vaporization of heavier components of the solution gas. The vaporization of these components is believed to be a cumulative effect of contact of the oil with bypassing, light-gravity gas which had been liberated at higher pressures from solution in oil farther back in the formation, or which had come from the gas cap, rather than from the singular effect of gas evolution caused by excessively low bottom-hole pressures. Change of oil composition caused by the latter was found to conform closely to that occurring during a differential liberation of gas in the laboratory.

Jan 1, 1967

By Keith S. Olson

During 1982 and 1983, the Bureau of Mines concentrated its fugitive dust control research on haulage road dust suppression by newer chemi-cals relatively unknown in the mineral industry, innovative dust control designs for haulage trucks, chemical tailing basin stabilization, and combined chemical and vegetation tailing basin stabilization. Relatively unknown dust suppression chemicals and innovative aerodynamic modifications to haulage truck fender designs were tested on a Minnesota sand and gravel operation haulage road. Magnesium chloride salt at 95-pct control efficiency and a petroleum derivative at 70-pct control efficiency were effective in suppressing dust generated by haulage vehicles; however, none of the fender modifications were successful. Commonly used dust suppressant chemicals were tested on a Minnesota taconite tailing basin to reduce the dust lift-off during the spring and fall dry seasons. The most successful chemical was lignin sulfonate with a seasonal cost of less than $200 per acre to achieve 90-pct dust control. When chemical treatments for immediate dust control were com-bined with revegetation for permanent control, the most promising chemical treatment based on vegetation response was lime-neutralized lignin sulfonate.

Jan 1, 1987

By E. B. Nelson, B. W. Gandrud, B. M. Bird

"The Lewisburg No. 2 mine of the Sloss-Sheffield Steel & Iron Company is located in Jefferson County, Alabama, about 7 miles due north of Birmingham. At this point the coal from the Mary Lee seam when coked in by-product ovens yields an excellent quality of metallurgical coke suitable for use in the iron blast furnace; it is also an excellent steam coal. In mining, all three benches are worked. Coarse impurities are largely gobbed by the miners underground.In addition to giving the data obtained from screen-sizing and float-and-sink tests of a representative sample of the raw coal, this report presents the results of slotted-screen tests to show the proportions of flaky particles in selected sizes, and the results of tests to show how much coal is liberated from impurities by crushing the coarsest sizes. These data have been obtained in connection with an extensive study of coal-washing now being conducted by the U. S. Bureau of Mines and the University of Alabama, with U. cooperation of the different operators of Alabama. As the work progresses other reports will follow containing furtner data on the washability both of the Mary Lee seam and of other seams in Alabama and giving the results obtained in preparing these coals by various methods.Although a great amount of investigative work on the preparation of the Mary Lee scam was previously carried on by the various coal companies of the district, comparatively little of this information has been published. In governmental publications three references have been found. Forbes5 gives a number of sections with proximate and ultimate analyses of face samples taken in the mines. Gandrud and Britton'' show sections of this seam at Flat Creek and New Castle; they also give the specific gravity and ash contents of the partings of coal and impurities. In their paper Yancey and Fraser7 include washability studies and washing data from the Sayreton mine of the Republic Iron & Steel Co."

Jun 1, 1930

By Mackenzie Burnett

The Brattice Window Method was used to measure the leakage rates of a total of 42 ventilation stoppings in 8 hardrock mines. Various types of stopping construction were evaluated. The following types are listed in order of decreasing effectiveness: 1) Cinder block, 2) Timber and mortar, 3) Timber and polyurethane foam, and 4) Timber and brattice material. There are slight differences in the effectiveness of the first three types, while the timber and brattice type is substantially inferior to the others. The repeatability of the Brattice Window Method was found to vary with physical conditions in the mine such as stopping location with respect to intersections, regularity of drift cross section, and the presence of hardware such as air and water pipes, timber sets and wire mesh. The Brattice Window Method is viewed primarily as a tool for estimating and comparing stopping leakages for the purpose of determining where repair efforts should be concentrated. A laboratory test program resulted in the derivation of several "rules of thumb" for employing the Brattice Window Method, which will aid in securing accurate and repeatable data.

Jan 1, 1979

By George T. Krempasky

This report is one of a series of Bureau of Mines Information Circulars dealing with mining methods and costs throughout the United States. It describes drifting, crosscutting, and raising operations at several mines in the Coeur d'Alene mining district, Shoshone County, Idaho. Ore bodies in the Coeur d'Alene district are generally in steeply dipping tabular ore zones, are irregular in shape, erratic in occurrence, and have been extensively mined along the strike and down dip. Because of the extended attitude of the deposits a great deal of development work is required. Drifting, crosscutting, and raising methods are described in this report. Shaft sinking is the subject of another report in the same series.

Jan 1, 1960

The Use of Automated Mineralogy to Interpret the Batch Flotation Performance of Merensky Reef Ore

Sep 13, 2010