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By G. F. Kuncir

The analysis summarized herein evaluates the Bureau of Mines Program for Advancing Mining Technology Oil Shale in terms of the economic benefits which may be derived for the Nation as a result of its successful research and development efforts. On the basis of postulated oil shale production scenarios, benefit-cost ratio indicators are computed for the program elements as they apply to surface, underground, and modified in situ oil shale mining systems. Eight value indicators are used to measure the Program's beneficial impact on the future oil shale industry in relation to planned research and development costs. These are: capital cost savings, operating cost savings, labor savings, environmental quality maintenance cost reduction, reduction in production costs, byproduct production benefits, total production benefits, and additions to recoverable reserves. Program costs are aggregated from 1974 through 1987 and major benefits are accrued from 1982 through 2040. Both cost and benefit streams are discounted to mid-1975 present value.

Jan 1, 1977

By I. J. Brown

Paper prepared for presentation at Industrial minerals and the environment, held in Leeds, 24-35 September 1990. The need to submit an environmental statement (EIS) has certainly increased the workload of those concerned with both its production and assessment. However, there is now good evidence that the system is enhancing public confidence in the minerals industry in particular and improving relationships between the developer, planning authority and those consulted such as statutory bodies, parish councils, civic societies, nature conservation interests and ramblers

Jan 1, 1991

By Herbert H. Einstein

Instability of rock slopes often occurs in the form of excessive movement of bodies that are bounded by discontinuities. The well known limit equilibrium analysis for wedges and blocks suffer, however, from procedural simplifications and from the basic deficiency of limit eguilibrium analysis--the rigid body assumption. Thus, stability analysis for 2-and 3-plane wedges with a wide range of additional features regarding failure modes and external forces have been developed. The deficiency, due to the rigid body assumption, was corrected by an approach that includes the effects or the in-situ stress field and of the stiffness of discontinuities. The final step in making limit equilibrium approaches more valid was achieved with the method of artificial supports which makes it possible to identify among all possible failure modes the critical one and to determine the corresponding factor of safety. The analytical development includes the creation of appropriate computer codes and routines for programmable pocket calculators.

Jan 1, 1979

By A. E. Tercan, D. Mamurekli

Ordinary kriging on the assumption of a gaussian error distribution and indicator kriging were used to derive the probability that a given calorific value would or would not be exceeded by coal from an area of a deposit. The two techniques led to similar probability maps despite local differences; the lack of an absolute reference makes it impossible to judge which method is better for this particular application

Jun 19, 1905

By D. J. MacDonald

Wettability measurements and laboratory waterflood tests were compared under a wide variety of conditions. Experiments were conducted with synthetic and natural crude oils, treated and untreated outcrop and oilfield sandstone cores, and synthetic brines with and without caustic, detergent, or phosphate additives. Measurements were made on equilibrated and unequilibrated systems at 77° and 150° F. Wettability was evaluated by the Bureau of Mines method from capillary pressure curves determined with a centrifuge. The waterflood data were fitted by empirical curves; the parameters of the curves characterize primary and subordinate production and also give the ultimate oil recovery. Results showed that wettability measurements at 77° F were useful predictors of recovery efficiency in waterflood tests run at both temperatures. Oil recovery in the early stages of waterflooding increased with increasing water wettability; however, the ultimate recovery was highest at a slightly oil-wet condition. The oil displaced at highest speed in the centrifuge was correlated with ultimate recovery in waterflood tests. Chemical additives to the brine sometimes lowered wettability and also sometimes improved waterflood recovery, but wettability and recovery were not correlated with additives present. The effect of additives on recovery in waterflooding was best seen in water-oil ratio curves.

Jan 1, 1974

By Jerry J. Ran

In open stope mining borehole deviation is one of the main factors affecting the blasting results. Though previous research has identified some actual deviation patterns, these studies are unable to relate the hole deviation pattern with the blasting results and therefore it is not possible to modify the design or take remedial measures based on the prediction of the blasting results. An alternative to the conventional method for borehole surveying is the in-hole probing techniques. With their inherent errors, it is important to evaluate these surveying systems under conditions of different mine sites. The lack of available assessment methods has limited the application of these techniques. In this paper some of the characteristics of the actual hole deviation pattern are discussed based on data from surveying production holes in six stopes. A method of predicting the blasting results is proposed by considering the borehole deviation pattern. Based on the prediction stope design can be modified or further surveying is carried out to improve the blasting results. The tolerable error is introduced to relate the surveying error with the drilling pattern and therefore it is possible to assess various in-hole-surveying techniques.

May 1, 2002

By James R. Boyle

The Bureau of Mines initiated a program to address short-and long-term objectives of wetlands restoration as a option for reclamation of lands mined for phosphate. The short-term objectives were to identify a suitable wetland test site, initiate an extensive premining monitoring plan, develop an acceptable mining plan, and recontour and revegetate the test site. These goals were accomplished using a unique combination of expertise provided by Federal and State agencies and private industry. A 6.5-ha forested wetland with an associated streambed was offered by private industry as the test site. A premining monitoring program was established and carried out from May 1982 to October 1983. A control site was established to determine ecological changes unrelated to mining. Clearing and mining began in October 1983 and was completed in April 1984. Grading and streambed restoration was completed in February 1986. Revegetation of the site was completed in February 1987. The program to meet the long-term objective of postmining monitoring is described.

Jan 1, 1988

This Bureau of Mines report comprises tables listing the name, location, and other pertinent data concerning certain future fuel-related projects. The tables include information on projects involving the proposed or planned development of fuel resources, as well as the development of storage, transportation, and conversion facilities; the report covers the 26 States east of the Mississippi River. Of the total 594 projects for which information is provided, 492 concern coal mines and electric generating plants.

Jan 1, 1976

By Michael M. Hamilton

In 1984 and 1985 the U.S. Bureau of Mines performed a mineral survey of the South Jackson Mountains Wilderness Study Area covering 60,211 acres of mountainous terrain of Humboldt County in northwestern Nevada. Approximately 550 lode claims have been located within or adjacent to the study area from 1900 to the present. Total recorded production for the area is 28.19 ounces gold, 1,105 ounces silver, 959 pounds copper, 6,016 pounds lead, and 12,446 pounds zinc; an additional two carloads from one mine contained an unknown amount of metal. In early 1986, there were eight active properties with a total of 126 claims. Wescord Resources and Long Lac Exploration (Texas) Inc. are involved in a joint exploration of the Jackson Mountains for volcanogenic massive sulfide deposits. Development at the Claudia mine continues in 1986. Results of the survey indicate that there are no identified mineral resources or reserves within or adjacent to the study area. Twenty-two properties have mineral occurrences containing gold, silver, copper, lead, zinc, iron, antimony, vanadium, and cobalt, with silver, copper, and iron being the most abundant.

Jan 1, 1987

By Georgene Renner, William R. Yernberg, Steve Kral

Allmand exhibited its LSC 100Light Sequence Commander, the mining industry’s first automatic lighting and command control system. The system is available with all of Allmand’s portable light towers. The LSC100 uses a preset photocell sensor that allows the light tower to be automatically turned on or off. At dusk, the sensor engages the power unit and then activates the light. At dawn, the sensor automatically shuts off the light. The unit also features an eight-event digital timer that allows eight separate sequences daily. The LSC100’s sequenced light control ensures that the engine is started before the lights are turned on or off. This prevents possible generator damage that can occur if the unit is powered down under load. Also, a low-fuel shutdown sequence helps protect the generator from damage by automatically shutting down the unit when the fuel level reaches 10 percent. And the LSC100’s smart circuitry senses engine water temperature during startup, determines the glow-plug time requirement and schedules repeat intervals, if necessary, to start the diesel engine.

Jan 1, 2004

By Thomas E. Doerfler

Information and data related to the occurrence of fatalities due to major disasters in metal/nonmetal underground mines were analyzed. Standard statistical methods were used to estimate the probability of occurrence of major disasters, and to examine the relationship of disasters to injury statistics published annually.

Jan 1, 1980

By Robert J. Pokora

This report summarizes the work performed under USBM Contract No. J0100038, "Demonstration of Noise Control Techniques for the Crushing and Screening of Nonmetallic Minerals." The objectives of the program were to: a. Identify the prevalent sources of crushing and screening noise in portable and stationary plants b. Design retrofit noise control treatments for those sources c. Field test control treatments under actual operating conditions. A census of the nonmetallic industry was performed to determine the number and types of crushing and screening equipment. Based on the census, eight plants were selected and surveyed to assess the variety of noise sources, determine the worker noise exposure to those sources, and to identify possible constraints that had to be considered in designing and installing the retrofit controls. Three plants were selected from those surveyed and retrofit noise control treatments were designed, including: a. A primary crusher operator control booth b. Screen decks made of resilient cloth c. Screen feedbox impact pads d. Rubber feed plate for secondary crusher e. Rubber feed chute linings for secondary crusher f. Noise attenuating curtain for secondary crusher. A new primary crusher control booth was installed at one plant, and the operator noise levels were reduced from 97 dBA to 78 dBA. Screen noise at the two secondary crushing plants was reduced by 3 dBA to 7 dBA; crusher noise was reduced by 5 dBA at one of these two plants. Noise levels at normal outside operator and cleanup locations were reduced by 4 dBA to 7 dBA at one secondary plant, but operator/cleanup noise levels were not significantly reduced in the second plant due to rapid wear of installed materials. At one of the two secondary plants the retrofit noise control materials displayed excellent wear characteristics. The rapid wear of retrofit materials at the second plant was due to improper materials being supplied and changing circuit conditions.

Jan 1, 1982

The collapse of the I.T.C., the subsequent fall in the price of Tin, and the lifting of quotas saw the Renison concentrator resuming full seven- day operations at maximum capacity in 1985/86. Performance was sus- tained in terms of grade and recovery, and in some areas improved, over this period. A further challenge was declining head grades, and the need to treat higher proportions of less amenable ore types. The complexity of the flowsheet and the method of mining and ore handling predisposes the process to unstable operation, and solving this problem comprises a major component of the current development effort. The concentrator has an imbalance of capacity between processes, and excess in some areas is being adapted to enhance the capacity of others. Magnetic susceptibility of various minerals is being exploited to greater effect. Significant performance gains are achievable by improving exist- ing unit process efficiency, particularly in grinding, gravity processes and Cassiterite Flotation. This paper reviews the metallurgical developments, both recently implemented and planned for this year, which have contributed to main- taining Renison Limited in a competitive position in the post I.T.C. Tin industry.

Jan 1, 1988

By W. A. McKinney

The segregation process consists of heating crushed oxidized or mixed oxide-sulfide copper are with a copper-volatilizing salt and carbonaceous material at about 750° C. to produce metallic copper which is recovered from the furnace calcines by conventional sulfide flotation. The Bureau of Mines made a number of bench-scale laboratory tests on two copper ores to determine the relative merits of using halogen salts, potassium chlorate, or various salt mixtures as volatilizing agents in segregation of the copper. Laboratory investigation of typical siliceous and calcareous oxidized ores revealed that sodium chloride was a better segregating agent than the other salts. Calcium chloride, magnesium chloride, sodium fluoride, or potassium chlorate gave nearly as good segregation as the sodium chloride on the siliceous ore. Segregation of the calcareous ore with calcium chloride was nearly as good as that obtained with sodium chloride, but inferior segregation resulted when magnesium chloride, sodium bromide, or potassium chlorate was employed. The use of sodium bromide or sodium iodide on the siliceous ore, and of sodium fluoride or sodium iodide on the calcareous are, gave appreciably poorer segregation than sodium chloride or the other salts. Other tests of the ores, using mixtures of sodium chloride and the other halogen salts or potassium chlorate, gave segregation approaching that obtained with sodium chloride.

Jan 1, 1962

By J. A. Finch, Zhenghe Xu

The competitive adsorption of xanthates on sulphide minerals in a binary mineral system (pentlandite and pyrrhotite) was studied using the pseudo-in-situ technique of attenuated total-reflectance FTIR spectroscopy. The minerals were placed in the same collector solutions, either separated by a glass wall or in direct contact with each other before magnetic separation and separate analysis. The effect of mineral interaction on xanthate adsorption was clearly demonstrated spectroscopically for the first time. At low concentrations of xanthate, its adsorption on pentlandite was activated by physical contact with pyrrhotite; the effect may be attributed to the enhancement of electron transfer through electrical contact between the two minerals. The results emphasise the need for caution in extrapolating results obtained from single-mineral studies to flotation practice

Jun 18, 1905

By R. V. Petrella

The flash induced combustion of Sewell and Pittsburgh coals was studied in air and in oxygen. The primary decomposition and combustion processes occur within the first 300 ~sec in oxygen and slightly later in air. Strong absorption spectra of CN and OH are indicative of the decomposition and combustion processes, respectively. Kinetic spectroscopy and combustion product analyses indicate that only about 35% of the coal dust is consumed in the explosive combustion which takes place in several (1-5) distinct but similar steps. The combustion-modifying effects of (NH4)2HP04, NH4H2P04, KHC03 and Rock Dust were studied in the 1-20 wt % range in coal dust flash com-busted in air and oxygen. The study reported herein shows Rock Dust to be the most efficient coal combustion inhibitor. KHC03 is the least effective agent, with the phosphate salts showing marginal effectiveness.

Jan 1, 1976

By Rita D. Sylvester

"THE BUREAU OF MINES was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve mineral resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting these industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with that directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau sources. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented III this special publication both necessary and valuable. This issue describes Bureau reports and articles published during the period January 1, 1960 to December 31, 1964. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960,2 and the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960.3 It supersedes the annual lists of Bureau publications and articles from January 1 to December 31, 1960/ from January 1 to December 31, 1961,5 from January 1 to December 31, 1962,6 and from January 1 to December 31, 1963,1 The leading general and technical libraries of the United States maintain files of the Bureau's publications. A list of these libraries appears immediately following this introduction. BUREAU PUBLICATIONSBecause some series of Bureau reports contain both free and sales publications, and because the cost of sales publications varies, prices are indicated in the individual listings of all publications for which charges are made."

Jan 1, 1964

By Michael Kelly

Inertial navigation technology has, for the first time, allowed the position of a longwall shearer to be mapped in three dimensions. Following the success of the technology in highwall mining and successful trials on a longwall face, the Australian Coal Association Research Program (ACARP) commissioned a three year "Landmark" project that aimed to advance longwall automation to the level of "on-face observation" by the end of 2004. This project has been completed with the following successful technical outcomes: Automatic face alignment was achieved, using an inertial navigation-based sensor on the shearer, to accurately measure face geometry and feedback signals used to move OEM (Original Equipment Manufacturer) roof supports. Operational on-line measurement of creep with creep information incorporated into face alignment corrections. Inertial Navigation System (INS)-based enhanced horizon control was bench-tested. Operational broadband communications system to shearer using wireless Ethernet on a commercial-product basis. Acquisition of located coal-face features for use in thermal infrared-based horizon control. Automated Longwall Information System (LIS) developed which integrates information from multiple systems and sensors and provides high quality visualisation and control interfaces. Automatic roadway and face convergence monitoring tools successfully tested. Condition monitoring tools developed and demonstrated for improved face reliability. This paper summarises the outcomes of the project and describes the work being undertaken for the 2 year Landmark Extension project approved in April 2005. Consistent with the conference theme, the paper focuses on the ground control aspects of the project.

Jan 1, 2005

By Donald O. Capstick

A mineral survey of the approximately 144,000-acre Borah Peak study area was conducted by the U.S. Bureau of Mines in 1985 at the request of the U.S. Forest Service. The area studied included the Borah Peak RARE II roadless areas (No. 14210, 119,864 acres of land recommended for wilderness designation; and No. X4210, 18,440 acres of land recommended as non-wilderness) and other contiguous Forest Service administered land. The study area is in Challis National Forest in southeast Idaho about 30 miles south-southeast of Challis, ID. Burnt Creek, a conterminous study area to the northeast, on lands administered by the U.S. Bureau of Land Managment, was examined concurrently. Dolomite and limestone inferred reserve bases exceed 1 billion tons each within the Borah Peak study area. The material is widespread and of high quality. Extensive sampling and more detailed mapping are required to better define the resources; however, ample dolomite and limestone occur nearby, outside the study area. Dolomite is the main constituent of several geologic formations within the study area. Sample analyses indicate that the more than 1,000-ft-thick Jefferson Formation dolomite is the most pure and is equivalent to material being mined at a dolomite-to-magnesium processing plant near Addy, WA. Analyses from limestone-bearing formations underlying much of the study area indicate that large quantities of the limestone may be suitable for a variety of uses.

Jan 1, 1987

By James H. Snyder

This final report presents results of a program to develop a new conveyor system, adaptable to existing miners or loaders, which reduces the noise level to 90 dBA without reducing machine performance. The trial conveyor design consists of a main conveyor and a swinging tail conveyor. The main conveyor incorporates a rubber-covered return guide roller, rubber mounting of pillow blocks, rubber cover of the return bed, and a rubber belt running between the flight chain and the conveyor bed plate. Testing took place in a surface coal pit and underground at the Peabody Spur Mines in Boonville, Indiana. Noise Levels as low as 90 dSA were observed on the surface and 93/94 dRA underground. Recommendations for further work are also presented.

Jan 1, 1976