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By W. R. Hardwick

This information circular describes mining methods and practices at New Cornelia Branch, Phelps Dodge Corp., Ajo, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The New Cornelia mine (fig. 1) is at Ajo, a town in southwestern Arizona (fig. 2) on Arizona State Highway 85 in the western part of Pima County. The [oncentrator] and smelter are near the mine (fig. 3). Copper ore is mined, crushed, ground, and concentrated, and the concentrates are smelted. Copper is cast in anode form and sent to the Phelps Dodge Corp. refinery in El Paso, Tex.

Jan 1, 1960

This Bureau of Mines report and its companion report (Information Circular 9143) have been prepared to assist in the preparation of prefeasibility type estimates for capital and operating costs of mining of various types of mineral occurrences using current technology. The handbook provides a convenient costing procedure based on the summation of the casts for the unit processes required in any particular mining or mineral processing operation. The costing handbook consists of a series of costing sections, each corresponding to a specific mining unit process. Contained within each section is the methodology to estimate either the capital or operating cost for that unit process. The unit process sections may be used to generate, in January 1984 dollars, costs through the use of either costing curves or formulae representing the prevailing technology. Coverage for surface mining includes dredging, quarrying, strip mining, and open pit mining. The underground mining includes individual development sections for drifting, raising, shaft sinking, stope development, various mining methods, underground mine haulage, general plant, and underground mine administrative cost. This system can be used for estimating cost data for an undeveloped deposit or for checking or verifying mining costs from a developed deposit, with a minimum amount of background information.

Jan 1, 1987

By Terry S. Cory

This report is a comprehensive summary of the results of the propagation measurements program conducted for the US Bureau of Mines under Contract H0366028. Data was gathered in the MF frequency range from a cross sample of six mines representative of the industry having typical wireless requirements. From the raw data which was gathered, a logical method of data reduction is presented which culminates in a set of average attenuation characteristics for all mines visited. These characteristics define a typical MF wireless system when the communication range requirements are known. Direct through-the-earth propagation and the range enhancement mechanism due to coupling on and off conductors are evaluated and related to the planning of a typical wireless MF communications system.

Jan 1, 1977

By R. S. Handy

This paper describing the milling practices at tae concentrators of the Bunker Hill and Sullivan Mining and Concentrating Co. is one of a series being prepared by the United States Bureau of Mines on milling methods and costs in the United States. The possibility of useful comparisons has prompted the description of all five of the mills operated by the Bunker Hill and Sullivan Company in northern Idaho. The general features of these mills are tabulated below: [ ]

Jan 1, 1930

The number of railroad coal cars (open top hoppers), dominated rail car orders and deliveries in 1975 according to announcements made February 11, by the Association of American Railroads and the American Railway Car Institute. Acting to keep ahead of increased coal production, the railroads installed 21,748 new coal cars in 1975, the most since 1957. The 1975 installation resulted in a net increase of 6,560 coal cars and an overall gain of 4.5 percent in the total capacity of the hopper car fleet. With most of the new coal cars going into unit train service --where car utilization is greatest --the railroads actual coal-carrying capacity was increased far more than 4.5 percent. The AAR estimated that unit train operations now move 50 percent of all rail-hauled coal compared to only 42 percent 2 years ago. COBALT - The Societe Miniere de Tenke Fungurume (SMTF) copper-cobalt project in Zaire reportedly was suspended in January for an indefenite length of time. According to officials, the deferment resulted from a number of adverse factors, one of which was exceptional increases in capital costs. The project was scheduled for completion in early 1978, with an eventual production of 14.3 million pounds of cobalt per year. Reserves of cobalt were reported to be 505 million pounds. SMTF is a consortium and includes American, British, French, Japanese, and Zairian interests.

Jan 1, 1976

Five watersheds, ranging in size from 29 to 49 acres, were selected in East-Central Ohio to investigate the hydrologic and water quality conditions occurring before, during, and after surface mining. Four of the watersheds will undergo surface mining, involving either the Number 6, 9, 11, or 8 coal seams, and one watershed having an outcrop of the Number 6 coal will be operated as a control watershed. To determine the premining hydrologic and water quality conditions (Phase 1), physical information was obtained for each watershed and instrumentation was installed for obtaining hydrologic data and water quality samples. In addition to topographic maps, soils and vegetation maps were prepared. Stratigraphic columns were developed from geologic cores; networks of observation wells and of soil moisture access tubes were installed; and weather stations were established to measure temperature, humidity, wind and solar radiation, and to collect precipi¬tation samples. Field data were collected over a 10-month period for one watershed and for about 8 months on another watershed before surface mining began. The other watersheds continued in the premining data phase. These data were for precipitation, temperature, relative humidity, wind speed, solar radiation, snow and frozen soil, soil moisture, infiltration (rainfall simulator), spring discharge, runoff from watersheds, and ground-water levels. Also, samples of runoff and ground water were obtained for chemical analyses and additional samples of runoff were acquired for suspended sediment load determinations. Over the study period, precipitation was not very representative of the long term averages, but data are available from the control watershed for a representative 7 year period which should prove invaluable in modeling the hydrology of the project watersheds for the premined conditions. Spring discharges (before mining) from the upper aquifer of two of the watersheds averaged only 508 and 652 gallons daily. The proportion of precipitation occurring as surface runoff from the large watersheds ranged from 8 to 36 percent and the peak discharges from 5.86 to 81.95 cfs. Base-flow and runoff water samples from four of the watersheds (unmined conditions) were collected and analyzed quantitatively for 39 water quality parameters. Monthly precipitation samples sediment fractions of the base flow and runoff were analyzed for 22 and 17 parameters, respectively. The average concentrations of the water quality parameters for the watersheds (unmined), except for suspended solids, were as low or lower than the EPA recommended maximum allowable concentrations in drinking water. Several parameters in precipitation equaled or exceeded the levels of corresponding parameters in runoff water. The average concentration of suspended solids in storm runoff ranged from 118 to 1110 mg/l, and for base flow the range was from 44 to 247 mg/l; the higher concentrations were associated with the watersheds exhibiting the greatest disturbance. Iron ranged from an average of less than 3 µg/1 to 228 µg/1. Manganese ranged from less than 41 µg/1 to 334 µg/I. Ground-water systems (unmined condition) are described for the five project watersheds. Each watershed was found to have two major perched aquifers within the top 250 feet. Generally, these perched aquifers involve local flow systems, though flow across watershed boundaries in some areas. Recharge is mostly from local precipitation and discharge is mostly as spring flow, base flow, evapotranspiration, and leakage through the underlying confining bed. Shallow ground water was commonly of the calcium bicarbonate type. Although dissolved-solids concentration was generally 200 to 600 mg/1, brackish or salty ground water was present in several areas. A composite hydrologic model for the project watersheds will consist of separate ground-water, unsaturated flow, overland flow, and evapotranspiration component models. The ground-water model (a modified quasi-three--dimensional U. S. Geological Survey model) operates on a grid network and the newly formulated unsaturated flow model was divided into overlying prismatic elements for numerical solutions. The unsaturated flow model includes provision for incorporating the evapotranspiration model. An available distributed kinemetic overland flow model was utilized. An analyses was made of one of the costs of reclaiming coal mines; the legal and administrative costs of complying with legislation. Such costs borne by coal companies under the Ohio law are thought to be a surrogate of these costs under the new Federal law. Regression analyses were used to relate the legal and administrative costs to acres in the permit and the tonnage of coal produced.

Jan 1, 1978

By C. G. Maier

Relatively infrequent use by metallurgists of the term "sponge chromium" as contrasted to more than occasional reference to "sponge iron" may be ascribed to the fact that the former material is not a commercial product, while the latter has been known and used, at least in one form (Swedish sponge iron), for several decades. It is doubtful whether a true sponge chromium ever has been prepared heretofore in the laboratory by more than one or two investigators. Nature presents a much. more difficult problem to the investigator endeavoring to make sponge chromium than pertains to the production of more easily reducible elements such as iron or nickel. Recent widespread interest among metallurgists in the possibilities of powder metallurgy is ample incentive to explore the feasibility of producing pure chromium metal in finely divided form. The shift in terminology of this statement from "sponge" to the "finely divided form" is deliberate in emphasis of distinction between terms that occasionally have been used loosely. It would seem desirable that a uniform usage descriptive of finely divided metals be adopted. While to some it might seem preferable that the terra "powdered" metal be reserved for a finely divided form produced by mechanical means, as, for example, chromium produced by the mechanical comminution of electrolytic sheets or flakes, current usage of the term "powder metallurgy' involves no distinction as to source type of material. It is usually accepted, however, that a sponge metal is one reduced from oxide or other combined form at temperatures below the melting point of metal or oxide so that the particles of metal are pseudomorphic, at least macroscopically, with the source material, and, in consequence of the loss of material without change of external shape of the particles necessarily have an open, porous, or "spongy" structure.

Jan 1, 1942

By William H. Schiffbauer

This report details a microcomputer-based control and monitoring network that was developed in-house by the U.S. Bureau of Mines and installed on a continuous mining machine. The network consists of microcomputers that are connected together via a single twisted-pair cable. Each microcomputer was developed to provide a particular function in the control process. Machine-mounted microcomputers, in conjunction with the appropriate sensors, provide closed-loop control of the machine, navigation, and environmental monitoring. Off-the-machine microcomputers provide remote control of the machine, sensor status, and a connection to the network so that external computers can access network data and control the continuous mining machine. Because of the network's generic structure, it can be installed on most mining machines.

Jan 1, 1993

By Oliver Bowles

The various Latin American countries are undergoing a slow process of industrialization. The harvesting of one or two agricultural commodities or the mining of a few marketable minerals is being supplemented by development of an Integrated industrial economy. In many countries, progress in this direction has not been rapid, but as it gains impetus an increasing market for cement is a natural consequence. This is evident from the fact that industrialization is linked with increasing transportation, and means of transportation are very poor in much of Latin America. Bridges, culverts, and concrete Highway's, now scattered sparingly throughout the vast land areas south of the United States, must multiply as the demands of industry increase and as a higher scale of living is attained. Eventually the South American countries will be linked by modern highways. Furthermore, the arid climate of many regions creates a demand for construction of dams and irrigation works, and a continent poor in coal reserves but with abundant water power inevitably must direct its energies toward the construction of hydroelectric power plants. Countries rich in raw materials but with few natural harbors have urgent need of massive concrete breakwaters and docks. The demand for concrete in houses will also grow. Standards of living are low, and perishable building materials are widely used. As living conditions improve cement will be used increasingly in home construction. Even in the field of simple and modest housing cement affords a means of creating low-priced verminproof and fireproof homes, for which the need it imperative under climatic conditions that prevail in this area of the world. Already many of the countries have undertaken extensive public works, and such programs are likely to increase. Assuming moderate industrial progress and stabilized governments the demand for cement in this great southern area promises substantial growth.

Jan 1, 1940

By William J. Krisko

This contract final report summarizes the design, fabrication and testing of a "line brattice air curtain" device under Bureau of Mines Contract H0357097. The purpose of this program was to develop the concept of using an air curtain for coursing ventilating air parallel with the air curtain From the last open crosscut to the face in exhausting ventilation systems to replace the line brattice cloth in room and pillar coal mining operations. The final design of the air curtain device consists of a 10-foot long closed end pipe with c: slot cut along its length. Pressurized air is delivered to the open end with a hydraulically-driven blower. A sheet of air emanates from the slot and is directed toward the mine roof. An invisible sheet of air is thus created between the top of the machine and mine roof and acts a an extension of the existing conventional line brattice.

Jan 1, 1977

By J. R. Thoenen

This circular is part 2 of the third subject (entitled "Excavation") of a series summarizing; the technical problems involved in the production and preparation of sand and gravel. Part 1 discussed the use of power shovels, draglines, and excavator cranes. This paper discusses the use of the power scraper, slackline cableway excavator, and hydraulic monitor, and part 3 will discuss the use of various types of dredges. Subsequent papers in the series will discuss the use of haulage equipment, the application of both excavating and haulage equipment to various types of deposits, and operating costs. THE POWER SCRAPER The power scraper is a younger member of the various forms of gravel excavators. It is a mechanized enlargement of the slip scraper and other scrapers which depend upon animals for power and has a greater range of operation from a single set-up than any other excavation unit except the slackline cableway excavator.

Jan 1, 1935

By Paul C. Hyndman

The U.S. Bureau of Mines inventoried Federal mineral lands in Idaho and classified them in detail, section by section, according to their availability for mineral exploration and development as affected by legal restrictions and agencies' management practices. The Bureau also identified known mineral deposit areas (KMDAs) and areas conducive to oil, gas, and geothermal resources. This information is shown on maps (developed in part by geographic information system technology) that spatially compare the availability for mineral entry of Federal land with these KMDAs to demonstrate the extent and severity of restrictions on mineral entry. Idaho contains 53.1 million acres, 35.7 million (67%) of which is Federal mineral land. About 7 million acres of this land is within KMDAs that host medium-to high-value locatable mineral deposits; 36% of this land is available, 27% is slightly to moderately restricted, and 37% is severely restricted or unavailable. For the leasable minerals, about 1.8 million acres are within KMDAs that host medium-to high-value phosphate deposits, about 5.4 million acres are favorable for oil and gas resources, and 3.9 million acres for geothermal resources. The percentages of land availability are 30%, 45%, and 25% for the phosphate acreage, 38%, 34%, and 28% for the oil and gas acreage, and 43%, 30%, and 27% for the geothermal acreage.

Jan 1, 2012

By E. J. Murphy, A. P. Rowles, John C. Holtz

"INTRODUCTION The use of sheaths or hollow cylinders of flame-extinctive materials surrounding cartridges of permissible explosives has been developed during the last few years; the history of sheathed explosives in their salient development in Belgium was treated recently in a publication of the Bureau of Mines. 6/ This development is of great interest in explosives technology, for it holds possibilities of reducing further the ignition hazards that may cause many coal-mine disasters. The township interest in sheathed explosives in this country is attested by the passage of some State laws permitting the use of such explosives on shift 7/; inquiries are received in increasing numbers concerning the effects of sheaths on practical hazards as well as the general technology underlying their use."

May 1, 1943

A symposium on pneumatic transportation of solids was held at Morgantown, W. Va., October 19-20, 196'), under the cosponsorship of the Institute ref Gas Technology. Chicago, Ill., and the Bureau of Mines. Objective of the symposium was to present information on developments and projected programs in the technology of feeding, transporting, recompressing, and utilizing gas-solids mixtures Dr. Henry R. Linden, Director, Institute of Gas Technology and Harry Perry, Director of Coal Research, Bureau of Mines, in the initial addresses at the symposium welcomed more than 140 representatives of industry, educational institutions, and government from 16 states, Canada, Great Britain, etc.

Jan 1, 1966

A symposium on pneumatic transportation of solids was held at Morgantown, W. Va., October 19-20, 1965, under the cosponsorship of the Institute ref Gas Technology. Chicago, Ill., and the Bureau of Mines. Objective of the symposium was to present information on developments and projected programs in the technology of feeding, transporting, recompressing, and utilizing gas-solids mixtures. Dr. Henry R. Linden, Director, Institute of Gas Technology, and Harry Perry, Director of Coal Research, Bureau of Mines, in the initial addresses at the symposium welcomed more than 140 representatives of industry, educational institutions, and government from 16 states, Canada, Great Britain, etc.

Jan 1, 1966

By O. P. Hood, R. H. Kudlich

When a gasoline locomotive is used in a mine there is danger of the noxious gases of the exhaust vitiating the air, but if enough air is circulating in those parts of the mine in which the locomotive is used, these gases are so diluted that they are rendered harmless, and the health of the workmen is not affected. In some mines the use of gasoline locomotives is impracticable, though in the majority of mines where they have been tried they have proved to be safe and economical. To determine the limitations that should surround the use of these machines in mines so that they shall not be detrimental to health and so that their economic advantage may be retained, it is necessary to ascertain the volume and the character of the exhaust gases and the amount of these gases that may be safely allowed in the mine air, and also to determine safe conditions of operation. The problem is primarily one of ventilation and like all ventilation problems must be intelligently computed to meet the conditions of each mine. The investigation described in this bulletin was undertaken 'by the Bureau of Mines in an endeavor to obtain exact information on some of the basal questions involved in the use of gasoline locomotives in mines, this investigation being one of many that the bureau has been conducting in its efforts to increase safety and efficiency in mining.

Jan 1, 1915

By Frederick C. Kohout

An advanced water-in-oil emulsion hydraulic fluid has been developed which meets defined laboratory performance criteria and which has given fully satisfactory results in a one-year underground mine test in two continuous miners. A novel method of monitoring fluid water content was demonstrated and incorporated into a test kit for use at or near the mine site. Test fluid fire resistance integrity as measured by the MSHA Schedule 30 procedure was maintained during the test and important fire resistance test variables identified.

Jan 1, 1979

By J. R. Thoenen, B. H. Clemmons, A. H. Reed

"INTRODUCTION AND SUMMARYOverall red-ore reserves in the Birmingham, Ala., area were estimated in 1910 by E. F. Burchard 4/. Since then mining has progressed into areas classed by Burchard as ""unavailable for exploitation"" under conditions existing at that time. This is understandable when it is considered that red iron ore was valued at $1.19 a gross ton at the mine in Birmingham in 19102/ and by 1948 had risen 300 percent; 6/ that skips had replaced cars in slope haulage; that mechanical loading and rubber-tired haulage had replaced hand loading and mule or locomotive haulage; and that other more efficient mining methods had been introduced. Intensive study during the intervening 40 years has been given to ways and means for upgrading the low-grade ores in the area and combining or blending them with raw red and brown ores for improved blast-furnace feed.It is reasonable to expect that future progress in mining efficiency and increased knowledge of the beneficiation characteristics of marginal ores will permit extraction of red-iron minerals now considered uneconomic.The Bureau of Mines has undertaken to restudy iron-ore reserves of the Birmingham area to determine what tonnage and grades of mineral are present; what is necessary to make them amenable to mining; what further advancement is possible in beneficia¬tion methods; and where increased production may be obtained in the area if and when required. This study has been underway for the past 2 years, but research into the beneficiation of marginal ores has been in progress at the Southern Experiment Station for the past 30 years. Many results of that research have been adopted in commercial practice in the area. Other results have not been published but are pre¬sented here in condensed form as an important factor in assessing marginal deposits with respect to their importance as ore reserves.An interim discussion of the salient features of past history and progress, as well as the data developed during the years of research in beneficiation at this station and the present field investigation, will make for a better understanding of the present position as well as be useful in evaluating future potentialities. Discussion in this paper is confined to the main Birmingham Basin area, which contains the largest concentration of hematite ores in the district."

Jul 1, 1953

By Dupuy. Leon W., R. T. C. Rasmussen, W. A. Calhoun

"INTRODUCTION For many years it has been known that low-grade manganese deposits occur in the bluffs along the Missouri River Valley. Frequent attempts have been made to develop the ore and to produce a marketalble commodity but they have had little success. Under pressure of the war emergency and the shortage of manganese, the attention of the Federal Bureau of Mines was directedtoward the deposits.Manganese-bearing shale occurs from a point near Pierre, S. Dak., down the river to the Rosebud bridge near the Nebraska line (1).5/ The Bureau of,confined its work to the more accessible central portion of the deposits near Chamberlain, S. Dak. The ore occurs principally as concretionary nodules in the form of iron and manganese carbonates (manganosiarite and perhaps some manganocalcite; rhodochrosite has not been identified). At the surface the carbonate is often broken down so that the oxide of manganese gives the nodules a black The matrix or host rock is generally known as Pierre shale, composed of ""interbedded layers of bentonite, an altered volcanic ash, and dissemi¬nated bentonite particles,"" (2) and montmorillonite-beidellite clay minerals (3). The shale weathers to the very sticky gumbo characteristic of South Dakota and well-known to hunters and travelers in the area.The area selected for the experimental mining and pilot-plant work discussed in this report lies about 8 miles westerly from Chamberlain and is a few hundred feet north of U. S. Highway,16, on land owned or controlled,by M. Q. Sharpe of Kennebec, S. Dak., and the General Manganese Corp."

Feb 1, 1946

1. Domestic Production and Use: In 1974 twelve companies operated 31 primary aluminum reduction plants, three firms accounting for 64% of production. Washington, Oregon, and Montana accounted for 32% of the total production; Gulf Coast States, 24%; Northern States, 33%, and other Southern States 11%. Output of primary metal in 1974 was valued at $3.4 billion. About 80% of the secondary recovery was from new aluminum base scrap and 20% was from old scrap. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1974, building accounted for about 27%; transportation 19%; electrical, 13%; packaging, 15%; and consumer durab1es, 9%.

Jan 1, 1975