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By Manuel Gomez

Dehydrogenation factors, proximate analysis, and ultimate analysis were examined as predictors of the low-temperature -carbonization properties of coals varying in rank from lignite through anthracite. All factors studied contributed to reduction in variance of the sample populations investigated. Response surface regression models based on variables from proximate and ultimate analyses of coal were constructed for eight low-temperature carbonization assay product and gas component Fields. These models were tested with independent samples that included drill cores, sized fractions, petrographic fractions, and run-of-mine coal. The models developed were used to predict low-temperature carbonization yields or coals from major fields of Wyoming. This information was cast in the form of contour plots describing the potential low-temperature carbonization product yields of Wyoming coals and the properties of the resultant char or coke. The variables used as input v the models may be measured and collected during exploration; thus, the carbonization properties of a seam can be determined in advance of mining. The information presented in this report is useful in that it broadens the deciionmaking base for management when either mine locations or coal conversicl plant sites, or both, are being considered.

Jan 1, 1971

By W. R. Hardwick

This Information Circular describes copper mining and concentrating methods, practices, and costs at the Silver Bell Unit of American Smelting and Refining Co., Pima County, 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 Silver Bell mining district, one of the older districts in Arizona, is in the western part of the Silver Bell Mountains in Pima County, about 40 miles west of Tucson and about 20 miles southwest of Red Rock, a station on the main line railroad of the Southern Pacific Co. The Oxide and the El Tiro open-pit mines of the American Smelting and Refining Co. are in the district (fig. 1. The principal ore deposits are in T. 12S., R.8E., Gila and Salt River base line, at an altitude of about 3,000 feet. The present town of Silver Bell, established in 1952, is reached by a paved highway, the Avra Valley road, that turns west from Highway 84 at Plata siding near Rillito and extends westward 25 miles to the townsite (fig. 2). The present town is about 5 miles southeast of the old town of Silver Bell that flourished from 1900 to 1930.

Jan 1, 1963

By W. R. Hardwick

This Information Circular describes copper mining and concentrating methods, practices, and costs at the Silver Bell Unit of American Smelting and Refining Co., Pima County, 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 Silver Bell mining district, one of the older districts in Arizona, is in the western part of the Silver Bell Mountains in Pima County, about 40 miles west of Tucson and about 20 miles southwest of Red Rock, a station on the main line railroad of the Southern Pacific Co. The Oxide and the El Tiro open-pit mines of the American Smelting and Refining Co. are in the district (fig. 1. The principal ore deposits are in T. 12S., R.8E., Gila and Salt River base line, at an altitude of about 3,000 feet. The present town of Silver Bell, established in 1952, is reached by a paved highway, the Avra Valley road, that turns west from Highway 84 at Plata siding near Rillito and extends westward 25 miles to the townsite (fig. 2). The present town is about 5 miles southeast of the old town of Silver Bell that flourished from 1900 to 1930.

Jan 1, 1963

By Robert S. Schechter

A minitest, consisting of an injection/production well and at least two observation wells designed to detect the arrival of injected fluid leached minerals, and nonideal flow, is considered in this report. The test goals are to determine the susceptibility of the host formation to uranium leaching, kinetic parameters to scale the process, and to facilitate site restoration. This report considers permeability and mineral heterogeneities and other oxidant-competing minerals. To circumvent these nonidealities, which obscure the results, methods of interpretation have been proposed and tested by a computer simulator. In complex cases, clear-cut methods of interpretation were not found; but in every case the design of a test most susceptible to interpretation has been considered. The minitest is operationally simple and can be completed in a short time. With the correct design and interpretation it can return information to evaluate economics, ensure satisfactory leachate performance, scale to larger operations, and to identify restoration problems.

Jan 1, 1983

By D. R. Nagaraj

The traditional (popular) approach to reagent development and optimization, which has become entrenched in both research and practice for many decades, is highly reductionistic, incremental and costly, does not produce robust chemical solutions, and is not sustainable. There are also several other key drivers and changes in the mineral industry that clearly warrant a new approach. In response to these, an intense effort was made at Cytec over the past fifteen years to develop a meaningful, efficient, and sustainable approach to develop new reagents and robust chemical solutions in mineral separations. This effort culminated in three important outcomes: a) development of the holistic approach, called FLOTATION MATRIX 100? process, b) novel reagents, and c) enhanced application knowledge for reagents. In this paper, the efficiency, utility and power of the holistic approach will be demonstrated with examples using both existing and new reagents in the processing of Cu-Au, Au and Cu-Mo ores.

Jan 1, 2014

By Allen L. Frank

The uranium mine environment is characterized by airborne radon-222 and its daughter products to which miners are exposed through breathing and by gamma and X rays from the uranium-235 and uranium 238 chains to which the miners are exposed externally. The nature of the radon-daughter concentrations and the methods used to define and measure the exposures are explained through an extensive review of the literature. An improved passive track-etch dosimeter for personal use is proposed which has a measurement range of about 30-400 WLH with a 95% confidence interval to ~25% for individual detector measurements in relatively stable mine air. Some measurements of these dosimeters adapted to environmental use are also presented. A program of development for enhancement of dosimeter sensitivity and greater accuracy of measurement is outlined. Extensive gamma-ray survey measurements were made in two Colorado and three New Mexico mines. Follow-up personal miner dosimetry with LiF TLDs was done at the mine with the highest exposure rates, The average miner exposure rate measured was 4.27 mR per day, or 9.3 of the maximum permissible level averaged over 13 weeks. Comparisons are made with previous mine surveys and their value in estimating miner exposure is discussed. Some depth-dose measurements made using Lucite as the absorber are evaluated.

Jan 1, 1978

By David Schlain

IN 1942 the Bureau of Mines began to develop the Kroll process for use in the large-scale production of titanium. Titanium and titanium alloys are now commercial metals. These metals are relatively expensive, but It is now evident that they will have important industrial uses and that in many instances these will be related to their remarkable corrosion resistance. This bulletin presents the known corrosion properties of titanium and its alloys in useful form. In marine environments titanium is highly resistant to corrosion and does not pit, or undergo crevice corrosion, stress corrosion, or corrosion fatigue. Titanium is also highly resistant in many salt solutions, including most chlorides. It is very resistant to corrosion in nitric acid solutions. It is also resistant to white fuming nitric acid. However, it may react violently with red fuming nitric acid. In phosphoric acid solutions titanium has rela¬tively good resistance to corrosion, but it has less resistance to sulfuric acid and still less to hydrochloric acid solutions. Titanium corrodes very rapidly in hydrofluoric acid Solutions. It is very resistant to corrosion in many organic chemicals. However, it has only moderate resistance to formic acid solutions and poor resistance inn oxalic acid solutions. Titanium does not corrode in dichloroaretic acid but, corrodes rapidly in 100 percent trichloroacetic acid at 100° C. Titanium is resistant to barium, calcium, magnesium, ammonium, and sodium hydroxides. Titanium is inert in wet chlorine, bromine, or iodine gases. However, in dry chlorine gas titanium reacts rapidly enough to ignite. It also reacts rapidly with dry bromine gas, but, it is resistant to dry iodine gas. When titanium is exposed to red fuming nitric acid solutions with high nitrogen dioxide content and low water content, it corrodes, undergoes stress-corrosion cracking, and becomes pyrophoric. This occurs more readily with some titanium alleys, such as titanium-8 percent manganese. A fresh titanium surface immersed in water or in an aqueous solution and in contact with an oxygen-rich atmosphere under sufficientt pressure is unstable and will ignite spontaneously. Inherently an active metal, titanium has a tendency to become less active in environments containing oxidizing agents such as air, oxygen, chlorine, or ferric, cupric, or platinic ions. Titanium is more noble than most structural metals in roost, environments and its excellent corrosion resistance is generally not, affected by contact with these metals. However, some of the other metals corrode faster because of contact with titanium. Titanium undergoes anodic polarization readily, so that even when it is the less noble member of a galvanic couple it may corrode less because of the contact. Titanium alloys often have corrosion properties and electrochemical characteristics similar to those of commercially pure titanium. Titanium alloys containing noble metals, zirconium, molybdenum, vanadium, tantalum, or copper sometimes have better corrosion resistance than pure titanium.

Jan 1, 1964

By James Westfield

Following is a brief history of Bureau of Mines Division of Coal-Mine Inspection activities that have favorably effected health and safety and reduced Injuries at coal mines: The Federal cline Safety Code for Bituminous Coal and Lignite Mines of the United States was issued originally by the Director of the Bureau of Mines on July 24, 1946, after consulting with management and labor representatives of the coal-mining industry. The code has been used by Federal coal-mine inspectors while inspecting bituminous-coal and lignite mines for the existence of unhealthful and unsafe conditions and practices in these mines. A revised code was issued by the Secretary of the Interior on October 8, 1953, after further consulting with representatives of management and mine workers, and was incorporated in the 1952 and subsequent bituminous-coal wage agreements. The agreement of May 29, 1946, betweeen the Secretary of the Interior, acting as Coal Mines Administrator under authority of Executive Order 9728, and the United Mine Workers of America, covering bituminous-coal and lignite mines in Government possession, charged Federal coal-mine inspectors with the responsibility of making periodic investigations of the mines and reporting to the Coal Mines Administrator any violations of the Federal Mine Safety Code. Federal coal-mine inspectors also had temporary authority to close mines considered imminently dangerous, but authority under Executive Order 9728 was removed on June 30, 1947, when Government control of the mines was terminated.

Jan 1, 1962

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 James J. Dowd

The investigation to evaluate the reserves of coking coal in the United States suitable for the manufacture of metallurgical coke is being made by the Bureau of Mines in three parts: (1) To estimate known (measured plus indicated) recoverable reserves of all coking coal; (2) to upgrade marginal coals through effective preparation; and (3) to study the carbonizing properties of coals and coal blends not now widely used for metallurgical coke making. This is the sixth of a series of reports giving the results of studies by counties under part (1) of the investigation. (See appendix.) This report covers Fayette County, Pa., which comprises the Uniontown and parts of the Brownsville, Connellsville, Donegal, Waynesburg, Masontown, and Confluence, Pa., Morgantown and Bruceton, W. Va., and Accident, Md., quadrangles. (See fig. 1.) A short resume of the chemical and carbonizing properties of the coals ar.9 included. Data on the coal beds in this county were obtained from mining companies, land companies, individual landowners, and other sources of authentic information.

Jan 1, 1951

By J. S. Limb

Actual issues which arose during the discovery process or subsequent court testimony are presented. While most of these issues relate to the author’s specialty of mineral appraisal some are more general in nature and could be of interest to those who may be involved in current or future court testimony. Several important areas to be reviewed and agreed upon with the client and their legal counsel are discussed. General observations on litigation, the discovery process, testimony and some repercussion’s are also given.

Jan 1, 2001

By K Rozlapa, P Waters, H Middlemis

A major challenge for closure planning at mining operations below the water table is evaporation from final void pit lakes and concentration of salts, which can impact on downstream groundwater (and surface water) flows and quality. Where such impacts are deemed unacceptable, the closure approach that is often adopted is to infill the final voids with waste rock to above the pre-mining water table to prevent the development of a pit lake and subsequent evaporative losses. BHP Billiton Iron OreÆs Marillana Creek (Yandi) mining operations face these issues. The orebody is a channel iron deposit that forms the major aquifer in the region, which will be completely mined as a series of elongated open pits over tens of kilometres. The major constraint on mine closure planning was the stripping ratio of less than one, which means that there is insufficient waste rock to infill all areas to the pre-mining water table. Hydrogeological investigations and groundwater modelling indicated that standard mine closure approaches would result in pit void lakes becoming saline sinks unless the residual void geometry was optimised to minimise evaporation and maximise throughflow. The solution developed is a cost-effective long-term mine plan that meets all mine closure objectives, and involved:the selective infilling of all pits, largely using run-of-mine waste dumping with limited re-handling; the diversion of the major part of up-catchment creek flows around the mining operations to allow mining of the resource under Marillana Creek crossings, which in turn restricted overall aquifer recharge and reduced the elevation of the long-term water table; the diversion of some minor creek tributary flows into specific locations within the mine path to induce hydraulic gradients to maintain groundwater throughflow and water quality; and close integration of mine plan optimisation (mining and waste dumping schedules) with groundwater modelling scenarios to achieve acceptable environmental outcomes. This approach is designed to result in no reduction in downstream surface water flows or quality, maintenance of adequate downstream groundwater throughflow to support groundwater dependent ecosystems, and no reduction in the beneficial use status of the downstream groundwater resource.

Jan 1, 2006

By M. J. Gavin

Within the past three years numerous inquiries for information on oil shale have been received by the Bureau of Manes. These inquiries have been increasing to such an extent that it has seemed advisable to issue a short paper prior to the publication of a bulletin on the subject, giving a, general discussion of the subject and a comprehensive list of references, so that those interested in the details of obtaining oil from shale can find additional information without much difficulty. Some of those who desire information are interested only in a general discussion of the subject, or are not in a position to refer to books and' articles describing the industry. The material for this paper is largely derived from published information on oil shale. Much of the information is obtained-from the books and articles mentioned in the list of references, and has been compiled with the intent of furnishing information to those not interested in all the details.

Jan 1, 1921

By Ramsden AR, French DH

The limited contrast range of conventional black and white imaging does not enable full use to be made of the dynamic range of the video signal obtained from a scanning electron microscope or microprobe. The use of false colour substantially increases the information that can be derived from such images enabling relationships to be displayed that cannot be observed in black and white. This capability is now used extensively in combination with quantitative electron microprobe analysis as a research tool for ore characterization and host rocks studies related to minerals exploration in the CSIRO Division of Exploration Geoscience.

Jan 1, 1989

By C. R. Kuzell

This paper, describing the concentrator practice of the United Verde Copper Co., is one of a series being prepared by the Bureau of HISTORY The United Verde concentrator was constructed in accordance with recommendations based on certain novel reasons which were quite different from those usually justifying the expenditure of such an amount. Concentrator operations started in March, 1927, although the metallurgical staff had considered for several years the eventual addition of a concentrator department.

Jan 1, 1930

By C. Heath

US coal consumption reached new heights in 1985, but production was constrained by excess consumer inventories. Domestic consumption of coal reached a record 742 Mt (818 million st) during the year. This is a 3.4% gain over the previous consumption high 718 Mt (791 million st) in 1984. An additional 84 Mt (92.7 million st) of US coal were shipped abroad in 1985, up 13.7% from exports a year earlier. Coal production in 1985 totaled 804 Mt (886 million st), 1.1% below the record 813 Mt (896 million st) produced in 1984. The slight decline in coal output is attributed primarily to a 13% drawdown of large consumer stockpiles built up in 1984 in anticipation of a miners strike that never occurred. Coal demand, and hence production, were also restrained by slower economic growth in 1985 and additional gains in nuclear generation of electricity. Domestic market requirements for coal in 1985 were mixed. Electric utility consumption rose 4.4%; coke plants consumed 6.7% less coal; coal requirements in the other industrial sector expanded by 2.1% and consumption in the residential and commercial sector fell 14.8%. The 2.2% increase in electric power generation in 1985 resulted in a 4.4% rise in utility coal consumption, totaling 630 Mt (694 million st) for the year. Twenty-nine of 45 states where coal-fired electric power plants were operating shared in the 26.7 Mt (29.5 million st) increase in 1985. Coal receipts at utilities fell by 16 Mt (18 million st) as these facilities worked off 21 Mt (23.4 million st) from stockpiles during the year. Electricity generation at coal-fired power plants similarly climbed 4.4% to 1.4 trillion kWh in 1985. This gave coal a 56.8% share of electricity generated from all energy sources compared with 55.5% in 1984. The average price of coal delivered to these facilities remained essentially unchanged during the year. It declined on 1.5% from $38.26/t ($34.71 per st) during the fourth quarter of 1984 to $37.70/t ($34.20 per st) in the fourth quarter of 1985. Coal consumption at coke plants continue to reflect a depressed steel industry. After rebounding 18.9% in 1984 for the first time in five years, coal consumption at coke plants again declined 6.7% to 37 Mt (41.1 million st) in 1985. Coke consumption 26.5 Mt (29.3 million st) exceeded production, 26 Mt (28.7 million st), in 1985. This resulted in a 1-Mt (1.2-million st) decline in coke stocks at producer and distributor levels during the year. The average price of coal delivered to coke plants decreased 7.6% from $64.30/t ($58.34 per st) during the final quarter of 1984 to $59.42/t (53.91 per st) in the last quarter of 1985. Coal consumption in other industries, including all manufacturing and industrial consumers except coke plants, totaled 68.3 Mt (75.3 million st) in 1985. This was the highest level attained in more than a decade. But the lower percentage rise last year (2.1% compared to 11.8% in 1984) reflected slower growth in the nation's economy in 1985. The average price of coal delivered to industrial firms declined 4.5% from $42.32/t ($38.39 per st) in the fourth quarter of 1984 to $40.39/t ($36.65 per st) in the last quarter of 1985. Coal-producing states in Appalachia mined 9.8 Mt (10.8 million st) tons less in 1985 than in 1984 for a 2.4% loss. The largest contributors to the region's production decrease to 393 Mt (433 million st) were Pennsylvania, down 14.7% to 60 Mt (66 million st); Ohio, down 8.3% to 32.6 Mt (36 million st); and West Virginia, down 2.9% to 115 Mt (127 million st). Conversely, eastern Kentucky production was up 4.8% to 111 Mt (122.8 million st) in 1985, while production in Tennessee climbed 9.7% to 40 Mt (44 million st). No coal was mined in Georgia last year. Coal production in the interior region in 1985 declined 3.9% to 173 Mt (190.4 million st). Substantial production losses occurred in Indiana, down 8% to 31 Mt (34.5 million st); and in western Kentucky, down 7.9% to 36 Mt (40 million st). Coal production in Texas rose 5.7% to 39 Mt (43.5 million st) in 1985. Louisiana began mining lignite 140 kt (151,000 st) during the year. Production in the western region increased 3.4% to 238 Mt (262.5 million st) in 1985. Wyoming, up 5.3% to 125 Mt (140 million st); and North Dakota, up 16.5% to 23.5 Mt (26 million st) contributing the largest amounts. Production gains were also shown in Washington, Utah and, notably, in Alaska where coal output climbed 72.9% to 1.3 Mt (1.5 million st) in 1985. Most of the additional coal produced in Alaska last year was shipped abroad. Coal stocks held by consumers totaled 154 Mt (170 million st) at the end of the year. This was 27 Mt (30 million st), or 13.7% below the inventory level at the end of 1984. Stocks held by producers and distributors declined by 868 kt (957,000 st), or 2.8% in 1985 to 30 Mt (33 million st). A drawdown in stockpiles occurred in each consumer sector during 1985. Stocks held by electric utilities totaled 142 Mt (156 million st) at the year's end, 13% lower than stock levels at the end of 1984.

Jan 5, 1986

By Frank E. Cash

Although during the past 10 years Alabama has attained an enviable position by its coal-mine accident experience and, like most of the other coal-mining States, has made progress in the safer operation of coal mines, there is still room for improvement, which can be realized only by still greater efforts on the part of employees and employers. From 1993, when accidents were first recorded by the Alabama State Mine Inspection Department, to 1934, inclusive, 3,451 men lost their lives in the production of 569,722,676 tons of coal. The primary purpose of this report is to bring to the attention of the mining industry in Alabama end elsewhere statistics of fatal accidents for 1931-34, with the hope that a study of the causes may lead to reduction of similar accidents in the future.

Jan 1, 1936

By H. Lyn Bourne

This marks the 15th consecutive year for this column. During 1995, readers were asked to supply royalty data for construction raw materials especially for states where none is available. The response was discouraging and royalty data are still missing for several states for either sand and gravel or crushed stone. Several readers have said that this article has merit but more new information is needed to justify its continuation. Several articles and pieces of news relative to mineral royalties appeared in the trade journals. R. Lee Aston (E&MJ, November, 1995, p. 16N) described South Australian royalties as amended by the government in1994. The royalty rate (a percentage) was lowered but the assessed value for minerals was raised and the current rate amounts to 20 cents//t (18 cents/st).

Jan 1, 1996

By Herbert R. Babitzke

The Minerals Availability System (MAS) was formally established by the Bureau of Mines in May 1975 to provide current appraisals of the engineering and economic availability of nonfuel minerals for consideration in the formulation of both domestic and foreign minerals policy, Domes- tic mineral property reports are developed by the Bureau's four Field Operations Centers, and foreign data are obtained under contract. This site-specific information is subsequently subjected to engineering verification and economic evaluation, and the results are analyzed and published as Minerals Availability System Appraisals. The deposit-specific data are also entered into the computerized MAS data base, where a subset of this information, the Mineral Industry Location System (MILS), is available to the public in the form of computer graphics and listings. Other MAS products are also described. The Bureau's MAS personnel are frequently involved in special engineering and mineral economic projects for other Federal and State agencies. MAS personnel also work closely with the private sector, both in the area of mining and processing cost estimation, and as a source of nonproprietary mineral deposit information.

Jan 1, 1982