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By John W. Motter

The Green Mountain Copper Prospect is an unusual stratiform base metal occurrence located in the California Foothills Copper-Zinc Belt. Mined for rich secondary oxide-carbonate ores since 1863, the first serious exploration of the primary ores was in the 1970's. Unlike typical volcanogenic deposits of the district, stratigraphy consists of greywackes overlain (?) or intruded by an intermediate to felsic volcanic unit. Shales and siltstones overlie the volcanic unit. Massive pyrrhotite, chalcopyrite and sphalerite occur at the top of the volcanic unit. Later intrusion and deformation metamorphosed the sequence and created a SW plunging anticline. Characteristic magnetic and electrical geophysical signatures are present and reviewed.

Jan 1, 1978

Remember, the good of the Institute is not limited to the technical papers. The acquaintance and good fellowship, the education and broadening effect of our meetings, can be made a real benefit for us all. Don't forget the meetings. The nest one will be at Denver, Feb. 26, 27 and 28. THE SECRETARY

Jan 1, 1922

By P. R. Jones

A computer program was written for the design of a shell and tube type heat exchanger on a price optimum basis. The program was designed to meet the following requirements: (1) Triangular pitch; (2) single or multiple pass; (3) heating or cooling; and (4) no change in phase. Price optimum design was obtained for four standard tube sizes and standard pitch. Pressure drop both inside and outside were computed and the nearest standard shells having at least the required area were listed. With this information, the estimator can select the heat exchanger best suited for the need. The program was made adaptable to various fluids and to various tube sizes and spacing by reading in much of the required data such as physical properties of the fluids, tube data, and standard shell data in tabular form.

Jan 1, 1967

By R. Newman

An inexpensive slow-speed data acquisition system has been adapted to digitally record multiple parameters simultaneously at intervals of 15 seconds. The system was built for use with standard soils testing equipment to automatically record load and displacement parameters at predetermined instants in time. Simultaneous readout is achieved by the use of special signal conditioner and sample-and-hold circuits which read the multiple signals simultaneously and hold them until the slow acting system can print out. Three channels of a 10-channel system have been converted and found to operate successfully during a series of direct shear tests. A unique feature of the system, which significantly reduced its cost, is the power supply units. Dummy circuits are used to maintain a constant power demand during sampling) thus eliminating the need for a costly power supply with rapid response characteristics. The entire system, having an overall accuracy of 0.25 percent, was put in operation for a cost under $2,500.

Jan 1, 1970

By Eric E. Cather

A mineral survey of a portion of the Lake Eleanor RARE II area (No. 5807), Trinity County, California, was done by the U.S. Bureau of Mines and U.S. Geological Survey (USGS). Approximately 8,650 acres (3,500 ha) of the Lake Eleanor RARE II area not examined for this report had been previously investigated by U.S. Bureau of Mines and U.S. Geological Survey personnel and published as part of USGS Bulletin 1371-B, (Hotz, 1972) Mineral Resources of the Salmon-Trinity Alps Primitive Area, California. The report showed that the section included in the rake Eleanor RARE II area contained no metallic mineral resources. Geochemical sampling indicated that the Lake Eleanor RARE II area contains no potentially important mineral resources. About 4,650 acres (1,880 ha) of the eastern part of Lake Eleanor RARE II area were examined for this report. The Bureau of Mines was responsible for detailed examination and sampling of mines, prospects, and mineralized zones; the Geological Survey conducted geological, geochemical, and geophysical studies of the area. This area is underlain mainly by granitic rock and serpentinite.

Jan 1, 1981

This manual provides instructions for installing, operating, and maintaining a protective canopy on the Galis Mfg. Co. face drill. The instructions are based upon an actual installation made in the mine on face drill model 460-S. The parts list and engineering drawings for the protective canopy are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other face drills with similar protective canopies. Skilled mechanics can determine if the instructions herein would be applicable to the other face drills and can determine any necessary modifications if they are not.

Jan 1, 1973

By A. R. T. Denues

"INTRODUCTION The orienting phases of the current investigation of cushioned blasting in the Explosives Division of the Bureau of Mines were indicated in a previous publication (5) 3/. Pertinent literature reviewed therein indicated a highly controversial field. This emphasized the need for experimental studies of many factors that affect the health and safety of miners and the efficiency of mining operations. Results of some orienting tests showed marked effects on practical hazards. Further, they emphasized the necessity and importance of the contemplated investigation. The scope and general plan of these practical inquiries into the safety of cushioned blasting were indicated.This investigation of cushioned blasting relates to the various means employed to reduce the intensity of application of energy from explosive actions in boreholes. It has been suggested (from p. 19 of reference that the divisions of this work would correspond to the salient hazards affected by cushioned blasting. These include the ignition hazard, hazards from poisonous gases, and other practical hazards in the blasting technique. The ignition hazard was resolved into two components of approximately equal weight. These include studies of effects upon (1) the incendivity of blown-out shots and upon (2) the occurrence of such shots. Experimental studies of effects on the incendivity of blown-out shots were first undertaken. Questions of the best procedure for making these evaluations have been adduced, and the interpre-tation and utilization of the results of gallery testing seemed to require detailed attention; some preliminary general considerations of such testing were therefore necessary."

Jan 1, 1943

[ ] ALVA L. SMITH RMCMI PRESIDENT 1989-1990 on behalf of the RMCMI Board of Directors and Officers of The Rocky Mountain Coal Mining Institute cordially invites you and your family to attend the 86th Regular Meeting and Convention to be held June 24, 25 and 26, 1990 at Sheraton Steamboat Steamboat Springs, Colorado

Jan 1, 1989

By R. L. Brown, H. G. Berger, E. F. Pohlman

"The Bureau of Mines in cooperation with the American Gas Association investigating the relation of properties of gas oils to the gum-forming properties of carbureted water gas. The present report deals with the effects of operating practice on the composition of the light oils from carbureted water gas. A general outline of the gummy meter problem has been presented in a previous paper.*Carbureted water gas is a mixture roughly of 80 per cent water gas by volume and 20 per cent oil gas. The latter, though small in relative volume, supplies more than half of the heating value of the gas under the present-day standard. Therefore, it is logical that the oil used in the carbureting process and the operating practices involved should be subjected to scientific study. Many investigations***** bearing on the aspects considered in this paper have been carried out in the past."

Oct 1, 1923

By Christopher F. Gleeson, Roger D. Thomas

"Abstract - Wawa has long been a center of mineral exploration activity and diamonds have been reported in the area since the 1930s. However, diamond exploration did not begin in the area in earnest until 1991. In 1993, Sandor Surmacz and Marcelle Hauseux of Saminex began a prospecting program in the area which culminated in their discovery of the "Sandor" diamond occurrence in an outcrop on the east side of the Trans-Canada Highway. They subsequently optioned the property to Spider Resources Inc. who obtained the necessary exploration permits from Algoma Central Corporation and undertook an exploration program. The diamonds at the "Sandor" diamond occurrence are hosted in the matrix of a spessartite dike composed of actinolite, biotite, and albite. Of the 64 similar dikes that have been sampled and analyzed to date, eight have been found to contain a total of 231 diamonds. Most of the diamonds are of high quality, although they are small.The dikes are non-magnetic and do not have any other geophysical characteristic that can be used to differentiate them from the adjacent country rock. All of the dikes discovered to date have been found by prospecting or by geological mapping by the Ontario Geological Survey. The dikes do not contain pyrope garnet or chrome diopside, two of the commonly used kimberlite indicator minerals. Instead, low Mg, high Cr, Zn-rich chromite, and ilmenites of variable composition, some of which lie within the field of kimberlitic Mg-ilmenite compositions, characterize the diamondiferous dikes. A regional-scale till sampling program for heavy minerals, and geochemical analysis of the <0.177 mm fraction, was used to further define the areas of occurrence of the spessartite dikes and to indicate additional areas for diamond prospecting. Heavy minerals in till that were most useful include: actinolite, chromite, and ilmenite. Geochemical analyses of the dikes show them to contain elevated concentrations of Ni and Cr and to be enriched in Ba, Co, V, Ca, Fe, and Mg relative to the surrounding rocks. Elevated concentrations of Ni and Cr in till occur overlying and down-ice of known lamprophyre dikes."

Jan 1, 2000

For the first time in its history the Institute will hold a meeting in the State of Arizona. A few years ago Arizona stood third in the copper-producing districts of the United States. Since that time, with the development of porphyry mines, the output has gone up with great rapidity until it not only is the leading district, but its output at the present time is at the rate of nearly double the Montana output, which now stands second in the list. In connection with this .development, most interesting departures have been made in methods -of mining, concentration and smelting. Principles of mining and metallurgy of the greatest interest will be covered by papers which will&apos; appear in the Bulletin and be presented at Technical Sessions, while ample opportunity will be afforded for those who go to the meeting to see all the points of interest .to them. In addition, members will be well rewarded by the marvelous natural features to be seen on the trip, including &apos;the petrified forests, the cliff dwellings on the Apache Trail and the Grand Canyon of Arizona. It is planned to start the special train from New York, but members and guests may join the special at other points en route as indicated by the following schedule: ITINERARY . , Thursday, September 14th Lv New York, Grand Central Terminal.. ............... 5.30 p. m. Dinner in dining car a la carte New England Members via B. & A. R. R. . Lv Boston. ............. (Regular train). ............. 2.00 p. m. Lv Worcester. ........... (Regular train). ............. 3.12 p. m. , Lv Springfield. ........... (Regular train). ............. 4.37 p. m. Dinner in Dining Car a la carte Ar Albany.. ......... .New York Central R. R.. ....... 7.45 p. m. Lv Albany .......................................... 9.00p.m. Lv Schenectady.. .................................... 9.32 p. m. Lv Utica ............................................ 11.08~.

Jan 8, 1916

By T. A. Grammatikopoulos, B. Vasily, A. H. Clark

"The St. Lawrence deposit is a large wollastonite skarn (ca. 9 Mt @ 41.3% wollastonite) adjoining the gabbroic-to-syenitic Leo Lake pluton in the granulite facies Frontenac Terrane of the Grenvillian Central Metasedimentary Belt. It occurs within a horseshoeshaped horizon of quartzite, open to the east. The skarn extends over 1.2 km2, and comprises wollastonite-dominant, wollastonite-clinopyroxene, and diverse quartz-feldspar-sulphide (-titanite) layers, interbanded with, and strongly folded within, the quartzite. As in the world-class wollastonite deposits of the Willsboro district, New York, no carbonate protolith is preserved, and calcite is a negligible constituent of the mineralized zones. Wollastonite development is nonetheless ascribed to metasomatism of a metacarbonate unit by magmatogene, silica-rich, CO2-poor (XCO2 < 0.05) fluids, at P = 350 MPa and ca. 560°C, or, alternatively, 550 MPa and ca. 630°C.Several high-grade zones, averaging >40% but locally exceeding 80%, of translucent, white, tabular wollastonite grains, with lengths of 0.2 cm to 5 cm, have been delimited by drilling. Preliminary beneficiation studies yield high aspect-ratio and high-purity (low Fe and Mn) concentrates.St. Lawrence compares favourably to other known prospects and operating wollastonite deposits: having good chemical and physical properties, low iron content, and high aspect ratios (>20:1). In addition, the deposit has a favourable size and location, and will benefit from a low Canadian dollar. Canada currently has no wollastonite production."

Jan 1, 2003

By Y. Luo

"It is generally known that spontaneous combustion potential is a function of coal rank, with low-rank coals having high susceptibility to self-ignition and high-rank coals having low potential. To establish this functional relationship and use it as an engineering tool to identify the propensity of coal to self-heat, both rank and spontaneous combustion potential should be quantified. ASTM D388 is normally used to classify coals by rank, but this classification system can only serve a qualitative analysis. To classify coals by their potential for spontaneous combustion, the self-heating temperature (SHT) method originally developed by the U.S. Bureau of Mines (USBM) was used by Litton and Page (1994) to correlate coal rank with spontaneous combustion potential. In that method, the SHTs of coal determined by an adiabatic experiment are linked with proximate analysis results through a proposed concept known as the “moist fuel ratio.” This ratio is a function of moisture, volatile matter and fixed carbon, all of which have widely different content percentages in different ranks of coal and have strong relationships with coal rank. However, the method is highly empirical, and there is large standard deviation between experimental data and calculated results. The equation correlating the coal quality parameters to determine SHT should be improved with more experimental data.This paper reports on the development of a new system for predicting the spontaneous combustion potential of U.S. coals, based on coal composition data from the U.S. Geological Survey’s coal quality database. First, the user is provided with a quantified classification of coal rank. Second, based on experimental SHT data covering a wide range of ranks from lignite to low-volatile bituminous coal, the original USBM correlation for predicting SHT is improved for the respective rank of coal. The relationship between the rank and SHT of U.S. coals was developed and plotted. The plot diagram can be used for a quick estimate of the SHT of a U.S. coal and as a cost-effective tool for the initial risk assessment of a new mine development."

Jan 1, 2015

By Michael S. Miller

During U.S. Bureau of mines mineral investigations, in 1981 and 1983, no mines, prospects, or mineral resources were identified in the Little Sand Spring Wilderness Study Area (WSA). Placer gold values in near-surface samples from alluvial fans within or near the WSA contained no more than 66 cents gold per cu yd, at $400 per troy ounce gold price. Sand and gravel and carbonate rocks occur in large quantities, but transportation costs to distant markets preclude their classification as resources. Nitrogen, lithium, clay, pumice, perlite, aragonite, and agate occurrences in the WSA are small or low-grade. The Silvia Mine, adjacent to the WSA contains gold-, silver-, copper-, and lead-bearing shear zones which strike toward the WSA. INTRODUCTION The Little Sand Spring WSA, encompassing 33,500 acres, is approximately 56 mi east of Big Pine, California, by paved and graded dirt roads (fl;. 1). Elevations range from 2,600 ft in Death Valley Wash to 5,600 ft along the California-Nevada boundary. The nearest permanent facilities are at Grapevine Ranger station and Scotty&apos;s Castle (Death Valley Ranch), about 9 and 11 mi, respectively, south in Death Valley National Monument.

Jan 1, 1983

By Others, C. M. Weld

During the past two years the Bureau of Mines has issued a series of mimeographed reports giving the results of research work and experiments conducted as part of its war minerals investigations. In this bulletin the reports on manganese are presented, which range in scope from the beneficiation of the ore to the utilization of the metal. The bulletin is in eleven chapters, each comprising a separate report, arranged in the order given below. 1. General information regarding manganese, by C. M. Weld. 2. Uses of manganese other than in steel making, by W. C. Phalen. 3. Problems involved in the concentration and utilization of domestic low-grade manganese ores, by Edmund Newton. 4. Preparation of manganese ore, by W. R. Crane. 5. Leaching of manganese ores with sulphur dioxide, by C. E. Van Barneveld. 6. The Jones process for concentrating manganese ores; results of laboratory investigations, by Peter Christianson and W. H. Hunter. 7. Cost of producing ferromanganese ores, by C. M. Weld and W. R. Crane. 8. Production of manganese alloys in the blast furnace, by P. H. Royster. 9. National importance of allocating low-ash coke to the man- ganese-alloy furnaces, by P. H. Royster. 10. Electric smelting of domestic manganese ores, by H. W. Gillett and C. E. Williams. 11. Use of manganese alloys in open-hearth steel practice, by Samuel L. Hoyt. As each chapter was originally prepared as a unit, there is neces- sarily some duplication and overlapping. With certain exceptions, however, each paper is reproduced in practically its original form. In chapter 1, covering certain general phases of the industry, such as uses, specifications, prices, and statistics, the subject matter has been somewhat modified in view of changes in conditions.About 95 per cent of the manganese consumed in the United States goes into the manufacture of steel. The remaining 5 per cent is used in a number of minor industries, the chief of which is the manufacture of dry cells. These minor uses are described in chapter 2. No discussion of the geology of manganese eres is presented, but a short bibliography on the subject is appended. With few excep- tions the manganese deposits of the United States are irregular, pockety, and uncertain. Largely for this reason, mining methods are crude and hardly warrant descriptions. The concentration of manganese ores, however, is an important problem and involves some details not common to other ores. Chapter 3 discusses the concentration and utilization of low-grade ones, notes the relationship of concentration to metallurgical prao- tices, outlines concentrating processes, and treats of commercial problems. In general, as regards concentration methods, manganese ores may be divided into two groups, as follows: (1) Ores permitting mechanical separation of the manganese minerals and the gangue, and (2) ores in which the manganese minerals and the gangues are so intimately associated that separation requires some hydrometal- lurgical or pyrometallurgical process. Heretofore, attention has been confined almost wholly to mechanical separation, chiefly by gravity. In fact, so far as known, all production of concentrates has been by wet gravity methods, although during the war some companies investigated the commercial pessibilities of magnetic separation and reported favorable results, the construction of one magnetic con- centration mill being started. The usual wet gravity methods are described in chapter 4. During the war, the Bureau of Mines undertook investigations of methods applicable to ores of group 2. A hydrometallurgical process involving leaching with sulphur dioxide was studied at the mining experiment station of the bureau at Tucson, Ariz. The results of this work, presented in chapter 5, indicate that the process is metallurgically feasible but the cost makes it unattractive. The results of an investigation of a pyrometallurgical process known as the Jones process are presented in chapter 6. The process, which is still in the experimental stage, was found to be metal- lurgically sound. The manganese product is not a concentrate but an alloy, made directly from a lean unconcentrated ore. The custom- ary method is to manufacture alloys from high-grade ores or from concentrates of leaner ores. A discussion of the costs of ferro-grade manganese ores is pre- sented in chapter 7. This discussion is in general terms only, but should be of use in so far as it relates to competitive conditions.

Jan 1, 1920

By Marcos Valdéz Córdova

El presente estudio señala el proceso de mineralización en el domo de Yauli a través de una revisión en el comportamiento de dominios estratigráficos, estructurales, intrusivos, metamórficos y distintos minerales de alteración hidrotermal. Asimismo se describe la geología, su estructura, la alteración de los intrusivos, la alteración de los silicatos metamórficos, la alteración de los mármoles y calizas dolimíticas, cuerpos, mantos y las vetas de reemplazamiento.

Nov 20, 1978

By A. V. Pavlov, V. A. Grygorian, Kossyrev, A. E. Semin, A. Korostylev

A new way of producing low-silicon ferrosilicon from iron-ore materials in a new type of aggregate-oxygen reactor is presented. The oxygen reactor process is based on using the calorific combustibility and reducibility of carbon materials inside the aggregate. The key to the process is successful post-combustion of carbon monoxide above a layer of a solid coke bed. Initially the possibility of production of grades of ferrosilicon containing 20 to 25% Si (FeSi20-FeSi25) was studied on a laboratory model of the oxygen reactor. Quartz sand and iron ore concentrates (from Russia and India) were used in the laboratory tests. This test work demonstrated that a ferrosilicon grade FeSi15 could be obtained directly from raw iron ore (containing 75.9 % Fe2O3 and a maximum of 23.8 % SiO2) without using rich iron-ore concentrates. The process was successfully tested on a pilot furnace at Serovsky metallurgical plant. Very promising results and efficiency parameters were achieved. The consumption of materials for 1t of ferrosilicon (15 % Si) production was as follows: 1567 kg raw iron ore, 591 kg of coal (in a composition of ore-coal briquettes), 299 kg of coke (for coke bed formation), and 815 m3 of oxygen.

Jan 1, 2004

By Emmanuel Henry

Few industries are more challenged by technical, political and market uncertainty than the mineral industry. Technical uncertainty in mining projects concerns the volume and quality of the resource, the processing and metallurgical parameters, the production efficiency, etc. Political uncertainty can take diverse forms and includes possibilities of change in the taxation system, risk of expropriation and risk of social instability or war. Market uncertainty depends on the market structure of the commodity; price and demand volatilities are the most common sources of market uncertainty. Intensive feasibility studies including these uncertainties and risks are required before investing up to billions of dollars in the development of a new mine. Current feasibility studies are often based on a single (or very few) mean geological scenario and simplified price profiles along the life of the project. Yet, strategic decisions, for example, the level of investment in exploration and metallurgical studies, adoption of a flexible, but more costly, mine design and risk-sharing strategies are made at an early stage. Over the last twenty years, Real Option theory has emerged as a unifying framework enabling strategic planning under uncertainty (technical, political and market). Geological and market variances (second order statistics) are pivotal for proper uncertainty quantification. The present study explores the possible benefits of combining modern geostatistical tools and financial techniques for project management. More precisely, the following questions are examined: Is geological uncertainty really an issue? Can we combine geological and price uncertainties in a unifying Real Option framework? A simple example aimed at illustrating the concepts involved is presented.

May 1, 2003

By L. C. IlsLey

Explosives have been fired electrically for several decades. Mountains have been tunneled, deep shafts sunk, extensive coal and metal mine workings excavated and, in times of war, railroads, buildings, bridges, and fortifications have been destroyed by means of electrically fired explosives. Modern engineering depends so much on explosives that their safe and efficient handling and especially their detonation are of prime importance to all those connected with the use of explosive agents. Electric shot-firing is only one method of igniting explosives, but it is rapidly spreading and because of certain inherent safety features should be encouraged. Data collected by the Bureau of Mines indicate that in the United States a large percentage of the blasting in quarries, shafts, and tunnels, and from 15 to 25 per cent of the blasts in mining operations, are set off electrically. The Bureau of Mines is interested in electric shot-firing because of its use in mining, and especially because electric methods, when properly applied, are undoubtedly safer than other methods commonly used.

Jan 1, 1926

By E. K. Kleespies

The Bureau of Mines demonstrated a technique for electrowinning titanium from titanium nitride and titanium dioxide. Titanium-nickel-copper metal solutions containing 26 to 61 weight-percent titanium were prepared by electrolyzing titanium nitride in molten mixtures of potassium fluotitanate) and sodium chloride or barium chloride and depositing titanium on nickel-copper cathodes. A titanium-nickel alloy was prepared by electrolyzing titanium dioxide in an electrolyte of potassium fluotitanate) sodium fluoride) and calcium fluoride and depositing titanium on solid nickel cathodes. This alloy contained 21 weight-percent titanium and had a combined oxygen-carbon content of less than 0.1 weight-percent. A compartmented cell confined the oxide feed near the anode and inhibited oxygen contamination of the metal.

Jan 1, 1966