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THE ore treated is almost pure copper pyrites (chalcopyrite) in a gangue of quartz and quartz-felsite. Very little free iron sulphide (pyrite) occurs, and at the time of the erection of the flotation plant the stopes in the oxidized zone had been almostentirely depleted. This zone only extends to a shallow depth, and, below the l00-ft. level, the sulphide for the most part is clean and bright but in the crushed and brecciated parts of the ore channel, where surface water has circulated freely, the gangue is decomposed and kaolinized, and the copper sulphide badly tarnished. This class of ore gave considerable trouble at the mill, but unfortunately, was very limited in quantity. A sample of rich ore assayed-Copper, 21.2 %; iron, 24:.3 %; silica, 28.9 %; sulphur, 25.1%.The concentration in the original mill was effected by handpicking, jigging, and tabling. A considerable portion of the copper mineral arrives at the surface in the form of large lumps of very pure quality, eminently suitable for sorting out by hand.The rich ore is tipped over a grizzly at the shaft bins; the oversize hand-picked, and the undersize bagged direct.

Jan 1, 1912

By Gill Montgomery

This report covers operations at the Crystal-Victory and Minerva No. 1 mines in Hardin County, Ill., which are operated by the Minerva Oil Co., Fluorspar Division, with offices in Eldorado. It describes the exploration, development, and mining practices, giving costs of each. Transportation, equipment, power, labor, and other influencing factors also are discussed. The mining methods employed are those most applicable to the flat-bedded replacement deposits common to the Cave-in-Rock section of the Southern Illinois fluorspar district. The fluorspar beds occur from surface exposures to 1,000 feet deep. In this district churn drilling is the method practiced for exploring flat-bedded deposits from the surface. Aerial photography and geochemical methods for indicating mineralization have been helpful in planning a drilling program. A program usually includes enough drilling to obtain only sufficient data on the value of the ore body and its structure to justify initial development and purchase of the mineral rights under option.

Jan 1, 1960

By P. Yant, R. R. Sayers, R. D. Lieitch

"PURPOSE OF INVESTIGATIONOf more than 300 bituminous mines examined by Crichton 5 and his assistants in connection with litigation in Indian Creek Valley, Payette County, Pa., only four were found to have alkaline water. That work and many observations from of the authors have shown the general prevalence or acid drainage from bituminous coal mines. In connection with investigations pertinent to coal-mine drainage that are being conducted by the United States Bureau of Mines, it was noted with considerable interest therefore, that a mine in the Thick Freeport bed about 20 miles north of Pittsburgh had no acid water in the workings, As it was thought that this condition might be common to all mines,this condition in this bed most of them were visited, samples of the outflow and from different parts of the mine inside were examined, and such general information as was available was gathered.ACKNOWLEDGMENTSThe authors acknowledge with thanks the courteous assistance of mine officials in connection with collecting the data for this paper, and of the analytical and coal laboratories of the Bureau of Mines for analyses."

Nov 1, 1932

By J. P. Capp

This experiment, one of a series on underground gasification of coal, was an investigation by the Federal Bureau of Mines of hydraulic fracturing as a means of increasing the air acceptance of a coalbed to permit introducing combustion air and removing product gases. Specific objectives of the investigation included: (1) Fracturing a coalbed; (2) determining the distance the coal was physically affected; (3) ascertaining the effect of the fracture on air acceptance of the coalbed; and (4) gasifying the coal. The coal was fractured with a fluid consisting of 15,000 lb. of sand mixed with 10,000 gal. of fuel oil and 5,000 gal. of kerosine, injected at pressures up to 900 p.s.i.g. and rates up to 425 g.p.m. The oil served as the fracturing medium, and the sand as a propping agent to hold the fracture open. From the fracture point, (the place in the bed where the fluid was injected), the fracture extended 200 ft. or more along the face cleats, somewhat less along the butt. cleats, and was confined to the coalbed. At the fracture point, the bed accepted about 500 std. c.f.m. of air, which was an etghtyfold increase. Fracture effects were extensive, as airflow was noted from old mine workings and outcrops 600 to 800 ft. from the fracture point. It is probable the actual fracture was much less than 600 ft. and that normal coalbed permeability beyond the fracture limits was responsible for this flow. This indicated that effects of the fracture extended beyond the area of coal physically affected. Although no attempt was made to gasify coal more than 200 ft. away, these effects plus the natural permeability of the bed likely would permit combustion beyond the outer limit of the fracture. As these experiments continued for more than 2 years, and greater air acceptance due to the fracture was observed at the beginning of each test, it is apparent that the effects of the fracturing persist for a considerable time.

Jan 1, 1960

By E. T. Bowers

Pneumatic conveying of coal underground is not widely used in the United States, although it is becoming increasingly popular in Great Britain, the Federal Republic of Germany, and South Africa. The question of safety has been raised repeatedly: Will the system be prone to dust or gas explosions, and, if so, can it withstand such occurrences safely? The work reported here was done under a Bureau of Mines contract and deals with the safety aspects of pneumatic transport of underground coal, as well as the hazards inherent in more conventional haulage systems. Included are three designs for different applications of pneumatic haulage: off-loading a continuous-mining machine on a room- and-pillar section, vertical hoisting through a 1,200-ft shaft, and off-loading a tunnel-boring machine driving a 2,000-ft tunnel.

Jan 1, 1985

By Herman W. Sheffer

This report describes and discusses present-day leaching technology employed to recover copper from low-grade mine and dump materials derived from the exploitation of copper ore deposits in the Western United States. Illustrations of the integral parts of the leaching, precipitation, and recovery operations at several copper-producing companies are presented. Schematic drawings are included to present typical flowsheets of leaching and precipitation operations. Operational problems common to most copper leaching and precipitation plants are discussed. Areas of present and future research to improve leaching techniques are cited.

Jan 1, 1968

By Karl J. C. Harries

"2.1. INTRODUCTIONNo agreement can be perfect in the sense that it contemplates and provides for all eventualities. Mineral acquisition agreements are usually negotiated and drafted at a time when an orebody is no more than a gleam in a geologist’s eye, so it is hardly possible to provide for development and operation in other than the most general terms. However, an agreement that stops short of contemplating the possibility of an orebody and production is ill-advised. Accordingly, it is important to provide procedures to make decisions that will let the project proceed, even in the face of a fallingout between parties. Whether the parties are shareholders in a corporation or venturers in a contractual common undertaking like a joint venture, differences of opinion and disputes will occur. Unfortunately, more and more are ending up before the courts. Besides greed and the growing tendency in society to fight rather than talk, there are other factors that contribute to the increase of litigation. In some jurisdictions, agreements have tended to become complicated, often defying interpretation, even by a lawyer, and explorationists want their budgets to go into the ground as constructive work rather than into a lawyer’s pocket. All this has led to a growing tendency for corporations to take the attitude that the chances of finding a mine are, at best, marginal and there are lots of earlier agreements in the files to draw from, so why not prepare their own agreements? As discussed in the preceding chapter, this can be folly. All these factors can quickly have parties facing each other in court while a project sits idle. Added to this is the problem that, in some jurisdictions, lawyers may take cases on a contingency-fee basis, sometimes promoting the pursuit of a nebulous claim.When an orebody is discovered, someone will always want some, or more, for himself. There is a breed of “prospectors” who prospect for legal actions, on the somewhat sound grounds that a major corporation will buy off nuisance litigation, rather than incurring the cost and effort of attacking even a poorly founded claim in the courts. They may even find a winner. Besides, it is far more comfortable and relaxing to prospect for problems and legal niceties than to prospect for an orebody.1 In short, it is appropriate to consider briefly some of the factors relating to lawsuits and judgments. Although many of the comments are made in the context of the common law and the Canadian legal system, most of the concepts and suggestions are applicable to any legal system."

Jan 1, 2003

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is intended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1977

By Paul M. Tyler

One by one new metals come to share the burden of modern industry. Long before the Christian era potters and glass workers employed fine and costly blue pigments that contained cobalt. Cobalt blue class has been found in the tombs of the Egyptians and in the ruins of Troy, and many of the colors used by the ancient Greeks and Romans contained cobalt. The ancients, however, were apparently unaware that the colors they used were caused by cobalt, and it was not until late in the 17th century that the existence of the element was recognized, Writers in the Middle Ages referred to "cobalos" as an evil spirit that haunted mines and caused trouble to the miners. Subsequently the German worms "Kobold," meaning goblin, came to be applied to any baffling mineral and particularly to minerals that resembled ores but failed to yield metal when smelted. Even to-day there is something of an air of mystery about cobalt, and a medieval cloak of secrecy still surrounds many of the metallurgical processes employed in its production. "Zaffre" was mentioned about the middle of the sixteenth century by Biringuccio, and in 1735 the metal war, first prepared by G. Brandt. To preparation of cobalt compounds, however, must have been carried on in at least a small way ever since the opening of the silver-cobalt deposits of Schneeberg in 1470. By 1790 there were 25 works engaged in the industry, rust of them located in Saxony, but the total output of these works probably did not exceed 300 tone of cobalt annually, mostly in the fore of smalt. The smalt which contained approximately 6 per cent cobalt was sold in Venice in 1520 at about 16 cents a pound. A few refineries in Holland supplied the Irish linen trade, contributed a farce amount to the Dutch linen industries, and alto provided smaller quantities for the manufactuer of litmus in Holland. A complete description of the early [histor,] of the cobalt industry in Saxony, is given by Mickle in the Deport of the Bureau of Mines of Ontario, vol. 19, 1913, pt. 2, pp. 234-251.

Jan 1, 1930

By John W. Kopp

A major concern with blasting at surface mines is generation of ground vibrations and airblast and their effects on nearby residences. This Bureau of Mines report looks at the use of millisecond delays in blast design and their effect on the resulting ground vibrations and airblast. A total of 52 production blasts were instrumented and monitored at a surface coal mine in southern Indiana. Arrays of seismographs were used to gather time histories of vibrations and airblast. The data were analyzed for peak values of vibration and airblast and for frequency con-tent. Various delay intervals were used within and between rows of blastholes. Delay intervals within rows were 17 and 42 ms, and those between rows ranged from 30 to 100 msj these intervals are equivalent to 0.5 and 1.3 ms/ft within rows and 1.2 to 4.3 ms/ft between rows. Sub-sonic delay intervals within rows reduced airblast by 6 dB. Large delay intervals between rows reduced the amplitude of ground vibrations; their frequency depended primarily upon the geology of the mine site.

Jan 1, 1986

By William W. Aljoe

The hydrologic characteristics of two abandoned underground coal mine sites, near Latrobe, PA, and Uniontown, PA, were investigated by the U.S. Bureau of Mines for possible implementation of alkaline injection into the mine pools as a means of abating their acid discharges. The Latrobe site was chosen for a one-time application of alkaline injection to achieve a partial, short-term neutralization of a limited portion of the mine pool. A quantity of alkaline reagent (sodium hydroxide) sufficient for a one-time neutralization of the water in this portion of the pool was added. Although nearly all of the neutralizing reagent had moved away from the injection wells within 6 weeks, no evidence of neutralization was noted at the mine discharge during the study period. This lack of neutralization probably occurred because the injection wells did not intercept a primary flow path through the mine. Criteria for successful application of alkaline injection at this or other sites include (1) positive identification of the primary flow paths through the mine pool and (2) addition of quantities of alkaline reagent sufficient to neutralize the entire volume of the pool along the primary flow path.

Jan 1, 2010

By Sir Stopford Brunton

Gold was first found in Nova Scotia about 1830-40, but its significance at that time was not appreciated. Probably the first discovery that resulted in any work was made by Lieut. C. !'Estrange, at Mooseland, on the Tangier river, in 1858.1 Since that time gold has been mined with varying success until now, and from 1868 onwards work has never altogether ceased. Gold mining in Nova Scotia is at the moment under a cloud, and the idea generally accepted by most people is that it has failed in the past, and that there is no prospect for it in the future. The actual reasons for the present situation have never been carefully analysed, and it seems a good thing to see what really is the state of the case and whether or not this general idea is worthy of credence. It is the purpose of the present paper to analyse the situation in the light of present knowledge, and to set forth some data which may assist in the future development of the Province.

Jan 1, 1926

By Alfred Bellows

The objective of this contract is to design, build and demonstrate a support system to improve roof control in the entries of longwall mines. The objective of this phase has been the detailed design of such a system and the selection of a test site in which to perform the pilot demonstration. The result is a complete set of detail drawings or specifications which define the three major components of the system. The Gate Support is a variation of a face chock which has an extended canopy and additional hydraulic legs to protect the region of the face-entry intersection. The Entry Support is a steel beam and hydraulic prop set which is reusable and serves to support the first 100 or more feet of entry inby the longwall face. The Transporter is a bolter-like vehicle with a crane used for installing and retreating the beam sets. The test site selected is CF&I's Allen Mine in Colorado. They presently use simi¬lar steel beams and expect the FMA support system to be more effective as well as recoverable. It is recommended that the completed drawings be used to build a prototype system and test it first in a remote section of the mine and then in the active longwall tail entry.

Jan 1, 1978

By Robert J. Evans

The Bureau of Mines is sponsoring a variety of long-term, high-risk research to advance state-of-the-art technology in U.S. underground coal mining. This report reviews the status of many Bureau projects that support fundamental underground coal mining operations; the project areas include cutting coal from the solid (extraction), hauling coal from the face (transport), and activities that sustain daily operations (logistics). Innovative equipment and technology have been developed, with these major objectives: to significantly improve coal mine productivity, to further advance coal recovery and personal safety within the mining industry, and to reduce the time needed to develop longwall panels. The majority of the prototype equipment covered in this report either has undergone or will undergo comprehensive evaluation at Bureau surface test facilities so that performance and reliability can be improved before the equipment is tested and evaluated in a working section underground.

Jan 1, 1988

By Lewis M. Haupt

Discussion of the paper of Mr. Granger, presented at the New Haven meeting, February, 1909, and published in Bulletin No. 25, January, 1909, pp. 1 to 37. LEWIS M. HAUPT, Philadelphia, Pa. (communication to the 'Secretary*) :-This subject is of great interest to me, and I am noting progress and conditions as a test of my own judgment in advocating what I believed to be the nearer, cheaper and better route at Nicaraugua. I have as yet learned nothing to change my views, or modify the convictions which led me to retire from the Commission; but that is not the issue to-day. Our government is committed to the Panama route, and is bound to " make good." There are many points presented by Mr. Granger which seem to me worthy of very serious consideration. But when all is said there remains the risk of seismic convulsions, to which either form of canal is subject; and I fail to see that the risk would be reduced by making the cut deeper, with greater surcharge of lateral pressure upon the side walls. A severe earthquake in the rainy season would doubtless close either type of canal. One of the arguments in favor of the Panama route most insisted on, was that Nature had provided good natural harbors at its termini. Recalling this, it has interested me to note that the cost of creating the necessary harbors is estimated at $27,000,000. Mr. Granger refers to this, and quotes the Board's report to the effect that, on the Atlantic side, it will require 5 miles of jetties to " make an excellent harbor out of a wretched one." The vulnerable part of Mr. Granger's paper seems to me to lie in the admission that the plant required is still in the embryonic stage, and that at least one machine should be built and tested " to demonstrate that the theoretical strains and forces work out in practice exactly as expected." This, how-

Jul 1, 1909

By Wilford S. Wright, Harold E. Heide, Robert L. Thorne, Neal M. Muir, Aner W. Erickson, Bruce I. Thomas

A program of investigation of strategic and critical minerals began in 1940 to examine and develop tungsten occurrences in the western United States and Alaska. During the years in which the nation was at war, this work was given special impetus to stimulate domestic production. This report is a compilation of results of the tungsten investigations in Alaska supplemented by certain data made available by the Territorial Department of Mines and is designed to include in its scope descriptions of all known tungsten occurrences in the Territory. Two areas in Alaska warranted special investigation - one at Gilmore Dome, 16 miles northeast of Fairbanks, and the other in the Hyder District, at the head of Portland Canal. Three tungsten properties - the Stepovich, Colbert, and Yellow Pup - are at Gilmore Dome. The Stepovich property, referred to sometimes as the Cleary Hill tungsten deposit, was worked by the Cleary Hill Mines Co. from April 1942 until May 1944 and was first examined by Robert S. Sanford and Norman Ebbley, Jr., engineers of the Bureau of Mines, in September 1942. The Cleary Hill Mines Co. by that time had explored an 800-foot strike length of the ore zone with 10 bulldozer trenches and was sinking an inclined shaft on ore in the central portion of the explored zone. In January 1943, the senior author, in company with Ebbley and Harry C. Doheny, supervising engineer of R.F.C., examined the property. Preliminary work by the Bureau of Mines began in May 1945, but actual exploration did not commence until late in June and continued until the end of October 1943. The deposit was examined by John B. Mortie, Jr., and William C. Overstreet, of the Federal Geological Survey, in 1942, and this study was continued in 1943 by Frank Byors, who also assisted the Bureau’s engineers on geologic problems. A magnetometer survey of this area was undertaken in 1942 by Henry Joosting and Eskil Anderson, engineers of the Territorial Department of Mines, and was completed with Bureau of Mines assistance in 1943. During 1943 the Bureau completed exploratory projects on the Cleary Hill mine and adjacent Colbert prospect. The field work on the Colbert property was begun early in July 1945 and continued intermittently until the end of October 1943, when it was recessed because of subzero weather. During September 1944, the Bureau of Mines established (by means of a few surface trenches) continuity between the Colbert mineralized zone, high on the dome, and the Yellow Pup vein, the lowest known tungsten mineralization in the area. It is generally recognized that any extensive program to develop the area as a whole logically would be carried out from the lower horizon.

Jun 1, 1948

Jan 1, 1993

A compilation of papers presented at the Third WVU Conference on Coal Mine Electrotechnology in Morgantown, West Virginia, on August 4-6, 1976. Papers cover areas of electric power, electronic communications, detection and location of trapped miners, and electronic sensors and monitoring systems.

Jan 1, 1976

By E. H. Burroughs

This bulletin is the sixth in the series of petroleum bibliographies published by the Bureau of Mines, Bulletins 149, 165, 180, 189, and 216 being compilations for the years 1915, 1916, 1917, 1918, and 1919- 1920, respectively. In this bulletin the same general plan has been followed in arranging the references, but one or two additions have been made in the classification.

Jan 1, 1921

About 90 per cent of the pre-mining BIF-hosted iron ore resource of the Hamersley Province of Western Australia is of the Phanerozoic supergene martite-goethite type. The remaining ten per cent formed as supergene deposits at ~2000 ¦ 200 Ma, and were later modified by burial to form the Proterozoic martite-microplaty hematite ores. The supergene-metamorphic segment of this general unified model has been challenged by three recently published hypogene-based genetic models for the hematite ores, all requiring meteoric oxidation to produce the ore. The most recent and detailed, by Taylor et al (2001), is based on data from the small Southern Batter and North deposits of the Mount Tom Price mine. The authors proposed that during Stage 1 æoverpressured bicarbonate-saturated basin brines from the dolomite aquifer of the Wittenoom FormationÆ at 150 - 250¦C, dissolved free silica from BIF to produce a stratigraphically thinned, magnetite-carbonate-silicate-apatite rock. In Stage 2, meteoric oxidation of siderite to secondary microplaty hematite + ankerite, and magnetite to martite, at unspecified elevated temperatures and pressures, was followed by carbonate leaching (Stage 3). Finally, during Stage 4, weathering with removal of apatite, produced the typical low-phosphorus, porous martite-microplaty hematite ores of the Tom Price-Whaleback type. However, evidence of both microplaty hematite and martite reduced to magnetite, and of infill silica, apatite, and ferroan chlorite, with late-stage pyrite, in the pore space of martite-microplaty hematite ore, shows that the hydrothermal activity at Mount Tom Price is a post-ore event. Neither pyrite nor ferroan chlorite could resist the oxidation required to form hematite ore. Recrystallisation of microplaty hematite in these infilled zones to a typically coarser form than present in most of the normal ores, is a further supporting factor. A more credible, post-ore alternative to the hypogene genetic model is suggested here. Re-exposure to leaching by ground water of the metamorphosed ore deposits in the Phanerozoic resulted in the partial removal of remnant goethite. Localised modifications in the porous BIF/ore contact zones were driven by exothermic oxygen/pyrite/carbon reactions in the footwall Mt McRae Shale. Cool descending oxygenated meteoric water in the permeable ore horizons, acted as one limb of a thermal convective cell. In the other limb, heated reducing solutions rose through the permeable contact zones, to produce the observed localised modifications of BIF and ore. Expelled silica from the carbonatised BIF invaded adjacent porous ore to form erratic silicified ore zones, and to produce the local quartz vein systems found in the associated overlying BIF.

Jan 1, 2002