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A new mine has begun production of antimony ore and concentrates in Serbia, Yugoslavia. The mine is operated by the mining and metallurgical enterprise "Aajaca." Initial production is running at approximately 45 thousand tons of ore per year, yielding about 1,500 tons of concentrate. The mine is located on the mountain Kopaonik-Raiceyoj Gori. It is planned to expand production eventually to approach the level of 300,000 tons of ore per year. This level will be a significant addition to the world supply of antimony and will place Yugoslavia among the world's major producers. Currently the United States produces only about 6 percent of its primary requirement for antimony. COBALT -Anglo American Corporation, Ltd. reportedly is considering restarting the Tenke-Fungurume copper-cobalt project in Zaire. Construction on the project was suspended in January because of inadequate financing and political uncertainties. Technical feasibility and financing on a smaller scale than previously envisioned are now being considered. However, an increased copper price may be necessary before any decision to proceed is made.

Jan 1, 1976

By R. Newman

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

Jan 1, 1970

By G. M. Potter, S. J. Hussey, R. Havens

The Artillery Peak manganese ores , from one of the largest known manganese deposits in the United States , present a difficult problem in concentration because they are low-grade and the association of manganese and gangue minerals is intimate and complex. The known size of this deposit has justified investigation of processes such as leaching, wherein preliminary enrichment of the original feed might be advantageous .. Therefore , the ore-dressing studies on Artillery Peak ores were carried on with the object not only of making directly marketable manganese products but also of removing acid-consuming calcite and raising the grade of ore for leachingplant feed . Owing to the extent of the deposits , test work was carried on at the Salt Lake laboratories in considerable detail on several lots of ore of varying composition . This paper summarizes the results obtained from laboratory testing of four samples obtained by engineers of the Mining Branch from the Maggie Canyon area of the Artillery Peak deposit . Also included are results obtained from testing one sample of Chapin Group ore , which was considered representative of numerous very low-grade ores submitted from the Artillery Peak district . During the course of the investigations , many data were obtained and compiled , but for the sake of brevity , data of secondary importance have been omitted or condensed and only those tests giving the more pertinent results are discussed in detail ...

Nov 1, 1947

By Robert C. Dyni

This report details the investigation of multiple-seam longwall subsidence conducted by the U.S. Bureau of Mines from 1978 to 1989. A field investigation monitored ground surface movements over four upper-seam longwall panels and six lower-seam panels. The characteristics of the subsidence occurring as a result of mining these panels are examined; in particular, the angle of draw, subsidence development, total magnitude and areal extent, and critical width are evaluated and discussed. Comparisons are also made between the characteristics of multiple-seam longwall subsidence and single-seam longwall subsidence that occurred at the same site.

Jan 1, 1991

By C. B. Manula

In this report, the application of the Open Pit Materials Handling Simulator (OPMHS) to a Southwestern surface mine using draglines and front-end loaders is described. The specific objective of the study is to demonstrate the application of the simulator to analyze mine planning and to analyze alternatives for increased production. The simulator was verified by comparing long term production figures to the simulated results from data collected on a mine visit. A short term and a long term alternative are studied with projected productivities and scheduling. No economic analysis of these proposals were performed.

Jan 1, 1977

By Kung-Lee Wang

This Bureau of Mines study illustrates the economic significance of the Florida phosphate industry to the State and to the Nation. Environmental considerations related to phosphate industry activity are discussed briefly. Based on forecasts of Florida phosphate production in 1975, and using 1972 dollars, regional and national output value, income, and employment created by the phosphate industry were estimated for 1975. State and Federal government tax revenues generated by the phosphate industry, are also measured. Further, the concentrated impact of the phosphate industry on certain Florida areas and on regional industries is examined. Finally, the phosphate industry's importance to the U.S. balance of payments, U.S. agricultural production, and the Frasch sulfur industry is considered, in addition to byproduct fluorine, and potential byproduct uranium from fertilizer manufacturing.

Jan 1, 1974

This publication summarizes, for potential contractors and other interested parties, the research, development, and demonstration contract projects programed by the Bureau of Mines for fiscal year 1982 (October 1, 1980 -September 30, 1981) under its Minerals Health and Safety Technology program. Contingencies may require that a significant port ion of the program be deferred into fiscal year 1983. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the systems technology required to create a healthier and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1981

By Steven R. Ruggieri

This report documents the work performed and the results obtained during the field demonstration of the Remote Sealing System at the USBM's Jenny Mine near Inez, KY in the Fall of 1978. Although various portions of the Remote Sealing System had been used on a number of prior occasions, the field demonstration at Jenny Mine marked the first use of the complete upgraded system including the use of the inert gas generating system for seal placement and the first application of the new froth foam system. The objective of the field demonstration at Jenny Mine was to demonstrate the complete system by emplacing and evaluating several complete underground seals under conditions representing those of a mine fire situation. Several critical sealing conditions were identified including: ? High entry airflow ? Standing water (1 to 2 ft) in the entry ? Flowing water (150 gal/min) ? Irregular roof ? Sealing a 4-way intersection. Four seals were successfully placed under the conditions mentioned above. The demonstration served to verify proposed techniques to handle these conditions as well as to dispel any doubts about the system's capabilities. As a result of the successful field demonstration, the Remote Sealing Equipment is now under the jurisdiction of MSHA's Mine Emergency Operation ready for a mine fire emergency.

Jan 1, 1980

By D. Oyler

The National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Research Laboratory (PRL), RAG Pennsylvania and Strata Control Technologies of Australia collaborated in an intensive study of ground behavior, reinforcement performance, and stress redistribution at the Emerald Mine in Southwestern Pennsylvania. The study site was a longwall tailgate subjected to a severe horizontal stress concentration. Field measurements indicated that the stresses applied to the study site nearly doubled during longwall mining, resulting in roof deformations extending to a height of 4.8m (16 ft) above the entry. A computer simulation of the field site was conducted using FLAC-2D, incorporating a broad range of rock behaviors and failure mechanisms. Comparison between the measurements and the simulation showed that the model was able to capture the most significant aspects of the roof and support system behavior, particularly, the extensive slip along bedding that created a partially destressed "softened" zone in the immediate roof. The model also showed that supplementing the normal roof bolt support pattern with cable bolts would allow the entry to survive a further 20-25% increase in the applied horizontal stress. Such information could have very practical application to the design of roof support systems for coal mines.

By Jérôme Boutin, Rémy Oddo, Sylvain Ouellette, Paul-Émile Boileau, Gilles LeBlanc, Pierre Marcotte

ackleg rock drills are widely used in the mining industry and are known to generate high levels of hand-arm vibration which contribute to the development of the hand-arm vibration syndrome for exposed miners.1-3 To reduce the vibration levels, a prototype of an antivibration handle was developed as part of a previous study.4 To provide some bench marking for this handle prototype and to follow the evolution of its performance over time, a test bench was developed to characterize the vibration emission values of jackleg drills under controlled operating conditions. As the current ISO 8662 series of standards could not apply directly to this type of tool, there was a need to design and validate a test bench to evaluate the vibration emission values of jackleg drills, while taking into account the conditions specific to the operation of this type of tool. Methods A test bench including an energy absorber, was developed for testing jackleg drills based on the ISO 8662-3 standard 5. The energy absorber was bolted to a 3300 kg concrete block to ensure tool stability. A pictorial view of the device is given in Figure 1. For validation purposes, acceleration measurements at the handle of a conventional jackleg drill were taken simultaneously along the three axes (xh, yh and zh) in an underground rock drilling operation as well as on the test bench. The handle accelerations were measured for three different jackleg angles (13º, 28º and 43º) determined with respect to the floor. Moreover, each measurement was repeated at least three times to asses the data repeatability. [ ] Results As a preliminary validation of the test bench, Figure 2 provides a comparison of the frequency weighted rms acceleration spectrum measured along the zh-axis, for both underground drilling and operation on the test bench (28º jackleg angle in both cases). It is shown that the vibration measured on the handle of a jackleg drill operating on the test bench is representative of that recorded during typical rock drilling operations, despite the fact that some harmonics of the percussion frequencies are generated with a higher amplitude on the test bench. Table 1 provides

Jan 6, 2006

By Kevin Hennings

Screening efficiency models developed to date rely almost exclusively on empirical formulas based upon large amounts of acquired operating data. A screening model was developed using a combination of empirical coefficients and explicit mathematical expressions which quantify screening phenomena. A series of screening tests was run to supply data for purposes of correlation and empirical coefficient evaluation. The model has been implemented as a digital computer program. The validity of the modeling procedure has been established by laboratory testing. Results generated by the model have been used to compile an applications handbook, which can be used to predict screening performance in lieu of using the computer program.

Jan 1, 1982

By J. R. Thoenen, J. L. Vallely, M. C. Malamphy

"SUMMARYMagnetic and gravimetric surveys wore conducted over an area of ap¬proximately 1,400 square miles in the bauxite district of central Arkansas. The primary purpose of these surveys was to discover any possible buried and hitherto unknown syenite masses favorable for the occurrence of bauxite and to determine the approximate position of the buried flanks of the known syenite masses which might offer conditions favorable for the discovery of new ore bodies.Those surveys indicated that the various syenite outcrops were domes or bosses on a large batholith and that ether similar domes occurred on the batholith but did net outcrop.Drilling on the local geophysical anomalies proved the presence of 10 buried domes, but only 2 of them were found to project above the upper surface of the Midway clays, a requisite of conditions favorable for the occurrence of bauxite ore bodies. The geophysical data indicated the approximate configuration of the buried flanks of the known syenite coutcrops, and the portions of these flanks that project above the Midway have now been outlined more accurately by drilling.The geophysical surveys have produced evidence permitting the elimi¬nation of a large area as unfavorable for the occurrence of bauxite.Magnetic surveys extending along the Midway-Wilcox contact from Gurdon, in Clark County, on the southwest to Searcy, in White County, on the northwest have proved the improbability of the existence of other syenite masses similar to those found in Pulaski and Saline Counties. A detailed magnetic survey of the Magnet Cove area in Hot Spring County has proved that the syenite mass exposed in that locality is an isolated intrusion and entirely unrelated to those of Pulaski and Saline Counties. This syenite mass does not occur under conditions believed to be favorable for the occurrence of bauxite."

Feb 1, 1945

By Russell R. Trengrove

The Copper Canyon lead-zinc mine is in the Battle Mountain. District, Lander County, Nev. It was discovered in 1866 and mined for copper until 1935 and for copper and gold until l948, when the main production became lead-zinc ore. The rocks in the area are carboniferous (Pennsylvanian and Mississippian) sedimentaries that have been intruded by quartz monzonite of Mesozoic age. They have been intensely folded, faulted, and tilted. Lead-zinc ore occurs as sulfides disseminated along fractured zones in a conglomerate arid hornfels. Development was carried out by the Bureau of Mines in cooperation with the U. S. Geological Survey and comprised a study of the geology, making maps and. cross sections, and exploring the deposit by diamond drilling from underground. Eighteen holes were drilled, for a total of 2,594 feet. This report contains a brief history of the property and a description of mining methods and beneficiation of the ore, geology, ore deposits and drilling done by the Bureau of Mines. It also contains detailed analyses of the ore samples taken and logs of the holes drilled.

Jan 1, 1951

By E. P. Youngman

In the Unfederated Malay States, with the exception of Johore, the rights of suzerainty, protection, and administration were transferred by giam to the British Government in 1909. In the States of Kelantan, Trengganu, Kedah, and Perlis, the rulers are assisted by State Councils and by British advisers appointed by the British Government.3 With respect to Johore, the largest, richest, and most highly organized of the Malay States not in the Federation, the treaty of December 11, 1885, with Great Britain, defined the relations of the State to the British Govern- ment and allowed the Maharaja to assume the title of "Sultan"; an amendment to this treaty (May 12, 1914) provided that the Sultan should be advised by a British officer, the General Adviser. ...... The political organization of the States is reflected in the mining legis- lation, Johore being the only one having a comprehensive code. The mining enactments now in force, according to the High Commissioner for the Malay States, are as follows:

Jun 1, 1932

As mine haulage vehicles become larger, the danger to a driver during a fire emergency is increased by the greater height of the cab above ground. Also, property damage due to fires on bigger trucks can be substantial. To solve this problem, the Department of Interior's Bureau of Mines, through two research and development contracts with FMC Corporation, San Jose, California, has developed two reasonably priced, reliable automatic fire sensing and suppression prototype systems for large haulage vehicles. At the onset of the large mobile equipment fire protection contract effort, it was learned that fires were frequently experienced in open-pit mine haulage equipment, especially large trucks. As the size of equipment has grown, so has the hazard presented to an operator forced to leave his truck in a hurry when fire breaks out and his normal path to the ground is blocked by flames. His only recourse is to jump from the cab platform to the ground, and the one-story drop of 10 feet or more can severely injure him. It is with these factors in mind that a program was undertaken to provide a fire detection and extinguishing capability tor the large mobile equipment, especially trucks, used in open pit mines.

Jan 1, 2012

By D. T. Couillard

Video technology is becoming an important tool for many designers of industrial training programs. This report describes how trainers at the Minntac Mine, Mt. Iron, MN, have developed videocassettes of safe job procedures (SJP's) for training miners assigned to perform unfamiliar work tasks. All steps necessary for videocassette production, from idea to finished product, as well as the required equipment and prices, are listed and/or briefly explained. Minntac officials believe that the SJP videocassettes have contributed significantly to a reduction in mine accidents.

Jan 1, 1985

By Thomas O. Meyer

Laboratory test results are presented for the determination of elastic modulus made with the NX borehole jack. Determinations were made in massive pieces of aluminum so as to satisfy conditions of linear elasticity, homogeneity, and isotropy. Results indicate a large discrepancy (approximately 200 percent) betwen material modulus as determined by laboratory block-loading tests and that indicated by the jack under relatively ideal circumstances. Effects due to interface friction, finite block size, incomplete plate-bore contact, and other factors were examined and found not to be significant. Finite element results indicate that assumed loading conditions for the jack differ from those actually occurring, at least in materials of high elastic modulus (approximately 10 million psi), such as quartzite.

Jan 1, 1974

By M. S. Fleming

The objective was to evaluate central lubrication systems for potential use on underground mining equipment. Previous use on continuous mining equipment resulted in poor system performance because of improper selection of lubricants, component failures, and an inconsistent delivery of lubricant to the bearings. The principles and operational characteristics of systems are reviewed and evaluated, and it was concluded that systems are available which can provide reliable central lubrication if properly applied, installed, and maintained. The procedures for applying a system to a continuous miner are discussed. Investigation revealed the lack of significant information on lubrication-related equipment failures and injuries related to maintenance and repair operations, the lack of significant failure rate data for central lubrication system components, and the lack of performance standards for central lubrication systems and components. To continue the development of systems for underground mining equipment it is recommended that a data bank on failures and reliability for equipment with and without central lubrication systems be created, and standardized specifications and performance criteria be developed for central lubrication systems and components which will be used on underground mining equipment.

Jan 1, 1979

By T. J. McDonald

The methods used and the results obtained in the application of high-expansion foam on a recent fire in an operating mine in western Pennsylvania were reviewed. This is the first instance where foam has been applied extensively to a fire under actual mining conditions although considerable research has been conducted and experimental fires have been controlled. The Bureau of Mines began investigating the foam-plug technique in 1957 in its experimental coal mine, following reports of successful trials in Eng-land, where the basic methods, using the normal ventilating current, were developed. Early in the research it was apparent that the normal ventilating current in mines in the United States would not provide adequate air pressure to drive a foam plug the distance that might be required. Subsequently, the Bureau of Mines developed a portable high-expansion foam generating unit consisting of a fan having relatively high pressure potential, net, sprays, and metering equipment. To date, foam generators have been constructed by the Bureau, by at least one operating coal company, and by one manufacturer of safety equipment. A number of units from the latter supplier have been adopted by coal-mining companies as an integral part in their firefighting installations.

Jan 1, 1961

By F. A. Penning

An experimental and analytical investigation was conducted on a recoverable pit bottom buffer. Work was conducted at the Colorado School of Mines using the U.S. Bureau of Mine-s free fall test tower. The four-sided butter, one of several designs by Cable Belt Ltd., was constructed of reinforced rubber slabs. The kinetic energy of falling weights, 1670 to 6000 lb, was absorbed by the flexure of rubber slabs loaded along their edge. A series of constant energy, 3000 ft-lb and maximum design velocity, 600 fpm tests were conducted. Static testing of the buffer established the load-deformation behavior. A large hysteresis loop plotted above and below the data published by the manufacturer. Creep was evident during; the loading Lend unloading cycle. Electronic instrumentation measured deceleration using your accelerometers; overall and intermediate movement was found from four displacement transducers; bending strains were recorded at four locations; and base reactions were measured by using four load cells. Data were recorded on tape and played back on a recording oscillograph. High speed movies were taken of all the tests. Symmetry of response and rebounds, when they occurred, were noted. From the displacement-time and load-time data, maximum decelerations were calculated by four methods and different assumptions. Good agreement was found from these approaches. Impact loads ranged from a low of 0.7 to a high of 6.1 gs. A dynamic computer model was written for the response of the buffer. Displacement-time, and acceleration-time plots show close correspondence with experimental data for the ten experiments. Data from accelerometers, displacement transducers, strain gages, and load cells are included. The computer program listing, and displacement-time acceleration-time plots are also presented.

Jan 1, 1980