Search Documents

"INTRODUCTION Industrial utilization of the present submarginal domestic manganese resources of the United States is wholely dependent at this time on the electrolytic manganese process established as the result of 4 years of continuous operation of the Bureau of Mines pilot plant at Boulder City and 7 years' operations of the Electro Manganese Corporation commercial plant at Knoxville, Tenn.Three Kids ore provided the feed for the Boulder City pilot plant during 3 years of operation. Hence, the electrowinning characteristics of the ore have been thoroughly established, making possible accurate estimates for commercial operations.Before the Defense Plant Corporation constructed the leaching plant, the Bureau of Mines conducted an exploration project to determine the extent and grade of the ore reserves. Additional exploration, development, and mining by the Manganese Ore Cc, have accurately determined the tonnage and grade of ore. A large tonnage of stock piled ore is now available for immediate processing, and a considerable tonnage of openpit ore has been stripped of overburden preparatory to mining. Numerous facilities, such as power, water, and housing, needed for an electrolytic manganese plant are already available.All of these factors, as well as plans for installation of scale electrolytic manganese plant facilities, are presented in detail in the chapter entitled, ""Mining and. Electrolytic Reduction of use from Three Kids Manganese Mine."" The Manganese Ore Co. kindly provided information on the present ore reserves and state of development of the mine."

Jun 1, 1945

By R. V. Ramani

In this the available information friction factors and leakage report, on characteristics are reviewed and summarized. The use of Penn State Mine Ventilation Simulator (Volumes II and III of the Final Report) to analyze the sensitivity of the ventilation system to the changes in leakage and friction factors is discussed with examples. In simple ventilation systems, the results of changes in leakage and friction factors can be easily solved and explained by the laws of air-flow. In complex systems, with fixed quantity branches and multiple sections, the effect of changes in leakage and friction factors cannot be generalized. This study points out the importance of good input data for obtaining reliable information from computer analyses and demonstrates the application of simulators to analyze the effectiveness of ventilation systems. An extensive bibliography on friction factors, leakage characteristics and ventilation economics is included.

Jan 1, 1977

By Robert Stefanko

Transients are results of sudden changes which take place in power systems and can be created by the opening and closing of switches and circuit breakers or the occurrence of a fault anywhere in the complex. Transients are of short duration, and the time during which they occur is an extremely small percentage of the total operating time. However, it is during these short periods that the greatest electrical stresses occur, mainly due to excessive currents or voltages. In extreme cases, system parts are damaged, and equipment failure follows. Safety can be further compromised because anomalous voltages can exist at machine frames. For several years, the electric utilities have been well aware of the serious nature of transients on their systems, but problems firmly believed to directly result from these phenomena are just now becoming apparent to the coal mining industry. The situation became discernible after the underground introduction of high voltage distribution systems (along with vacuum circuit breakers) and sensitive solid state electronic apparatus. In order to protect against such transients, knowledge about their characteristics and origin must be obtained.

Jan 1, 1974

By W. L. Dare

This report is one of a series published by the Federal Bureau of Mines to describe methods and costs of mining uranium on the Colorado Plateau. The Navajo Uranium Division of Kerr-McGee Oil Industries, Inc., mines uranium from several deposits of carnotite-type ores, which lie buried in the Lukachukai Mountains on the Navajo Indian Reservation, Apache County, Ariz. The country is rugged and isolated Constructing and maintaining roads has been a continuous task. The ore bodies occur within the Salt Wash member of the Jurassic Morrison formation and are similar to other such deposits on the plateau. The current mining activity in the Lukachukai Mountains is a result of uranium-ore discoveries in 1949, although the Navajos undoubtedly knew of the outcrops of yellow uranium minerals long before that time. The ruggedness of the country and the heavy soil cover over much of the surface hampered prospecting, but probably the main reason the ore was not found sooner is that no one took the trouble to look for it in the Lukachukai Mountains.

Jan 1, 1961

By R. M. Barker

The historic Getchell property is currently being mined from the Getchell Main Underground workings, a foot wall extension of the Getchell open pit deposits along the Getchell fault. Drift-and-fill techniques are used to extract the ore through a ramp access. The adjacent Turquoise Ridge deposit is currently under development via two vertical shafts. Together, the two mines will continue to provide feed to the Getchell's 3,200 tpd mill/autoclave circuit, taking Getchell Gold from its current production rate of 200,000 ounces (Au) per annum, to over 400,000 ounces (Au) per annum by 1999.

Jan 1, 1997

By Herry Poernomo, Agus Prasetya, Iga Trisnawati, Himawan Tri Bayu Murti Petrus, Gyan Prameswara, Panut Mulyono

We studied yttrium extraction from untreated zircon sand processing waste tailings. Xenotime mineral as the rare earth element source with an abundance of yttrium (REY) was detected in sufficient grade for extraction. As much as 9.03% yttrium exists in zircon tailings (analysed by X-ray fluorescence spectrometry). The presence of yttrium was confirmed by X-ray diffractometry in xenotime minerals, which are yttrium carriers (Y-PO4). The purpose of this research was to determine the effect of leaching conditions on yttrium recovery from zircon sand after alkaline fusion treatment. Alkaline fusion was chosen to decompose phosphate into hydroxide in the xenotimemineral,which will reduce further required hydrometallurgical processing.Alkaline fusionwas carried out for 3 h at 450 °C, with a ratio of sodium hydroxide to zircon tailings sand of ~ 1:1. The alkaline fusion product was leached with water, followed by hydrochloric acid treatment to leach the yttrium. Yttrium recovery reached 87% under optimum conditions (60 °C, 1MHCl, and solid-to-liquid ratio = 1/10 for 7.5 min). A suitable model for yttrium dissolution with hydrochloric acid was diffusion through a solid particle ash layer. The calculated activation energy (EA) for this model was 20.21 kJ/mol.

May 26, 2020

This report is the 21st in a series summarizing research and technologic work on coal and related investigations by the Federal Bureau of Mines - the Chard of the series published on a calendar-year basis 2/ Subject publica¬tions of the Bureau during 1956 are cited, and pertinent Bureau work is described briefly. The most effective method of conserving our important coal reserves is through improved technology of production and utilization. Associated problems form the program of the Bureau.3 4 5 6/ Potential production is depend¬ent on a knowledge of the quantity and quality of the reserves, and the Bureau continues to contribute information on this subject. Many problems are being studied that relate to improvements in current production, including mining methods and health and safety measures. Preparation of mined coal is necessary for its most efficient utilization. Preparation by conventional methods is being studied, as well as the development or new methods. Fundamental studies on the structure and properties of coal are necessary to insure full advantage of the special qualities of different coals. Controlling factors in the efficient use of coal in combustion, carbonization, gasification, and direct and indirect hydrogenation of coal are being studied continuously, and new processes are being investigated. The many advances in all these fields are discussed.

Jan 1, 1959

By Berger

A detailed description is given of radio apparatus for controlling a coincidence outfit for relative gravity measurements. This is probably of little interest, since many types of apparatus could be used. The general method employed is the interesting thing about this paper. As long ago as 1883 von Sterneck made a proposal to control two coincidence boxes with the, seine, clock, and many persons have suggested the use of radio for this purpose. In accomplishing this it would appear to the reviewer that this method is probably inferior to that used by the Marland Oil Co., but Berger and Brückner must be given the credit for important advances in the coincidence method. In their apparatus a clock at a central station actuates a relay, which operates a short-wave transmitter (40 m.). At the receiving station the amplification is accomplished at low frequencies... The signal operates a relay which moves a slitted screen in a coincidence apparatus. This screen has been improved considerably, to decrease the mean error in observing a coincidence. As usual, a telescope is used to observe the flashes of light. It has a scale in its focal plane and positions of successive flashes are easily read off and recorded by a second observer. This makes possible' a: higher accuracy in determining the exact instant at which coincidence would have occurred at the zero point on this scale. This method obviously depends on the constance of the mechanical and electrical lag inn both sending and receiving apparatus, and may be adversely criticized from this standpoint. -- A. E. Ruark.

Jan 1, 1929

By G. Goodlad

This paper describes some of the main aspects involved in implementing the European “Equipment and Protective Systems for Use in Potentially Explosive Atmospheres” (ATEX) Directive (No.94/9/EC) in the British mining industry by the year 2003. It provides a brief background to the Directive and considers its main objective of removing all barriers to trade in Europe. It outlines the need for the European Standards making bodies to write new editions of the ’explosion protection concept standards’ and for manufacturers to adopt new quality management procedures and develop new versions of equipment in conformity with the ATEX categories of “M1” or “M2.” Finally, it assesses the possible future relationship between the European enforcing authorities, manufacturers and users of explosion protected equipment.

Jan 1, 1999

By J. W. Thomson, H. J. Lloyd, R. J. Taylor

"THE HOLLINGER MINE has been producing gold and by-product silver almost continuously for forty-eight years. The value of current production is $10,000,000 annually from one million tons of ore. Its management •has, particularly over the past decade, increasingly . concerned itself with the problem of profitable operation in a time of steadily rising costs and a fixed price of gold. At one period in the life of the mine, before World War II, production resulted in yearly profit margins that were stable and relatively thick. In winning gold from a series of inconsistent vertical ore lenses, operating management was much better protected than it is today against a general rise in cost or dip in grade of ore. The tissue-like thinness of present-day margins demand more careful handling. A sharp rise in costs, if protracted, could easily rip the tissue to shreds and close down the business. The counter-measure of raising grade and gutting the mine would bring on the end perhaps more rapidly, without having contributed much to the recovery of our national re-sources, nor to community welfare. The alternative is to keep costs under control."

Jan 1, 1960

By A. B. Hooker

Nineteen of the installations were on rental contracts 1.L."'1der whtch the lamps belong to the lamp company and are rented by t.½em to the mine operatj.nt; company. · The other nine installations had been upon an O\Vnership-rental basis, by which the lamps had become the property of the renter at the end of 5 years. Five of t.11e rentec installations were en a special contract calling for a guaranteed light output. These contr2.cts were based upon certified . initial performance, with the provision that the lamps be replaced whenever periodic tests of fully charged lamps, taken at random from t..h.e charge racks, showed a light output of less than 80 percent of the certified performance.

Jan 1, 1942

By G Cooper

The Société Nationale Industriel et Minière (SNIM) is expanding its ore and concentrate production capacity in Mauritania, West Africa. This government-controlled mining company has been in production since 1963 and currently exports some 12 Mt/a.SNIM is presently doubling its magnetite concentrate production at the Guelb el Rhein mine. An existing processing line will have a second parallel production line of 4 Mt/a added. The mine is located some 600 km inland from the Atlantic coast in the heart of the Sahara Desert.The metallurgy of the ore is reasonably straightforward. It is a magnetite banded iron formation that is amenable to magnetic separation. While the existing plant uses semi-autogenous grinding and dry magnetic separation, the new processing line will use HPGRs, dry magnetic separation, and a wet milling and magnetic separation circuit for treating middlings.The process choices refl ect the scarcity of water in the region, the high cost of locally generated power and the operating experience and preferences of SNIM. Dust control in the desert environment has been a particular challenge.The metallurgical design aspects as well as the infl uence of the environmental and commercial aspects of the project are presented.

Jul 11, 2011

By T. M. Ahmed

Sherritt International Corporation experienced corrosion failures with the 316L stainless steel tubing in a high-pressure still condenser employed for ammonia recovery. A detailed failure analysis was conducted on the condenser tubing to determine the mode and the root cause of the failure. The analysis included both optical and scanning electron microscopy (SEM) of the inner and outer surfaces of the tube as well as characterization of the corrosion products using energy-dispersive X-ray spectroscopy (EDX). Results revealed that the corrosion attack was confined to the first ?100 mm of the tubing at the inlet where the tube was connected to the top tubesheet. The tube suffered both external stress-corrosion cracking (SCC) and crevice corrosion from the shell side (water side), and wall thinning of the inner surface (the tube side) due to erosion corrosion. It was evident that failure of one of the tubes occurred due to SCC that penetrated the whole wall thickness and resulted in a leak failure. Some prevention measures are proposed to avoid this type of corrosion attack in the future.

Jan 1, 2005

By C. Thomas Hillman

The practical concern of economic minability of large, high-grade manganese nodule deposits in the northeast Pacific Ocean is addressed in this Bureau of Mines report. Principal objectives are to (1) estimate tonnage and grade of deposits with significant potential and (2) describe and estimate profitability of operations designed to mine and process deposits with greatest apparent potential. Analysis of data from over 800 ship stations identified three areas for detailed study. Average metal contents of these areas range from 1.30 to 1.45 wt pet nickel, 1.00 to 1.24 wt pct copper, 0.21 to 0.26 wt pct cobalt, and 26.8 to 27.8 wt pct manganese. Estimated recoverable nodule resources are 67.0, 66.9, and 148.8 million dry metric tons (t). A system to mine, transport, and process nodules from the three sites is described and costed. Although hypothetical, the system utilizes hydraulic mining and Cuprion (Kennecott) processing, which have been successfully tested at pilot scale. Nickel, copper, and cobalt are the three primary products, but ferromanganese is a considered option. Estimated capital requirements are approximately $1.5 to $1.7 billion for three-metal production. If ferromanganese were recovered, an additional investment of about $130 million would be required. Operating costs range from $71 to $83 per dry metric ton of nodules without manganese, and from $103 to $123 per dry metric ton with ferromanganese. Discounted cash flow analyses predict low returns, ranging from 2.7 to 5.2 pct with ferromanganese and from 4.1 to 6.0 pct without.

Jan 1, 1983

By C. P. Bowie, George L. Gates

"INTRODUCTION Experience in drilling oil and gas wells has shown that the voidance of blow-outs, twist-offs, fishing jobs, loss of circulation, and heaving and caving of shale formations into the drill hole depends largely on how well the drilling-mud fluid serves its purpose. A possible method for the control of the drilling fluids may be seen from a study of the relation between the particle-size distribution and some of the important drilling-fluid properties, such as the ability to build quickly a relatively impervious mud sheath on the wall of the hole in the porous formations penetrated by the bit during drilling operations. In a wartime economy, which urgently requires conservation of steel, proper functioning of the drilling fluid is particularly important because, as Parks 4/ has stated, intelligent use of good drilling fluids makes possible drilling of wells for thousands of feet in open holes without the necessity of setting protective strings of casing to control the movement of salt water, gas, and troublesome formations into the borehole; consequently, especially in deep wells, of proper drilling fluids materially reduces the need for casing and lowers the cost of drilling and completing the wells."

May 1, 1942

By L. C. Karrick

The Bureau of Nines has received many inquiries on the subject of assaying oil-shales, both from individuals who desire to wake their own assay while in the field, and also from Commercial assayers and investigators. The present paper describes the assay retort used by the Bureau of Mines. in the research work on oil-shales now in progress at the Intermountain Experiment Station of the Bureau at Salt Lake City, Utah, and at the Colorado cooperative oil-shale laboratory, Boulder, Colorado. This retort, which was developed through experimentation in the bureau's laboratories, has been found to be convenient in use and. capable of yielding reproducible results. M. J. Gavin, Oil-Shale Technologist, gave valuable assistance in preparing the subject matter for publication and made many helpful suggestions during the experiments made by the writer in the course of the development of the assay retort. L. A. Anderson, research "fellow" University of Utah, assisted in the preliminary development of the assay retort.

Jan 1, 1921

By E. O. RHODES

Germany's' wartime coal-tar industry had two main branches, which can best be considered individually because their raw materials, operations, and distributions were almost completely separated. One branch, old and well-established, was concerned almost entirely with processing coal tar produced by the high-temperature carbonization of caking bituminous coal. Carbonization was effected principally in byproduct- coke ovens and to less extent in vertical, horizontal, and inclined retorts. The high-temperature tar was all processed in tar-distilling plants that handled high-temperature tar almost exclusively.

Sep 1, 1947

By E. J. Ostrowski, P. L. Woolf, J. P. Morris, Norwood B. Melcher

By injecting natural gas through auxiliary tuyeres into the smelting zone of the Bureau of Mines ' experimental blast furnace in January 1959 , the investigators succeeded in reducing the coke consumption by approximately one - third that of the base period . This caused a 30 - percent increase in pig iron production with no increase in wind rate . The maximum gas addition in these experiments was 4,665 cubic feet per ton of metal produced . Sharp reduction in gas consumption occurred when high hot blast and high wind rates were used , although the gas injection rate in percent of air blown remained constant . As the heat energy produced by burning natural gas to carbon monoxide and hydrogen is much less than burning coke to carbon monoxide , greater blast temperatures were required during the test runs . The gases produced from the methane were , however , more effective reductants ; so it was possible to increase the production rate while reducing the total heat requirements per ton of metal produced . During a base period with an all - sinter burden , before introduction of natural gas , a coke rate of 1,484 pounds per net ton of pig iron was attained , using an average blast temperature of 1,518 ° F. Gas was introduced gradually over a two -week period until an average 7 percent of the air blown was reached . During this period , the wind rate was adjusted downward to maintain a constant flow of gas in the bosh . The production rate of the furnace remained relatively constant . The quality of pig iron, however , improved as the sulfur load on the furnace was reduced as a result of the substitution of gas for coke . Blast temperatures were increased during this period from 1,518 ° F. to 1,939 ° F. , when the maximum gas addition was reached .

Jul 1, 1960

By Daniel S. Witkowsky

The Pollution Prevention Act of 1990 provides few specifics to assist the non-fuel mining and mineral processing industries of the United States in achieving pollution prevention (P2) compliance. The U.S. Bureau of Mines (USBM) recognizes the absence of specific information to reduce pollution impacts from mining and mineral processing of hardrock and industrial minerals. Therefore, the USBM has prepared this publication to help reduce or eliminate environmental pollution and to assure the viability of these segments of the domestic mining industry. This report includes worksheets designed to help operators of mining and milling facilities to establish a P2 program. The report can also be used by citizen and environmental groups, State and local governments, and academia to gain an understanding of P2 as it relates to mining and mineral processing.

Jan 1, 1995

By S Bluhm, L van den Berg

In planning mine ventilation systems, heat issues are normally associated with deep-level mines where auto-compression and virgin rock temperatures play a major role. However, a number of mines suffer from high ambient temperatures and humidity, very steep virgin rock temperature gradients and an influx of hot groundwater. Mines in Australia and, particularly, South-East Asia have to deal with these environmental conditions, both in the operational and planning phases. These operations normally have to take heat into consideration during the planning stages at much shallower depths. In high rainfall regions, the water table is saturated and groundwater flow rates are particularly high, which add significant water heat load potential to the mine ventilation system.This paper considers the ventilation challenges associated with hot groundwater conditions in mechanised mines. The paper is based on specific project experience gained from a number of projects in the United States, Australia and South-East Asia and draws on data from mines that experience hot groundwater conditions. For one site, actual decline temperature survey measurements, modelling techniques, management strategies and design considerations are presented.CITATION:Van den Berg, L and Bluhm, S, 2015. Ventilation planning considerations when dealing with hot groundwater, in Proceedings The Australian Mine Ventilation Conference, pp 211–218 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015