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By James J. Anderson

In this talk I will report on an effort to reassess the risk of pile driving to juvenile salmonids migrating through Puget Sound. The study was motivated by the concern of the construction industry that provisions restricting pile driving during the spring migration is resulting in an unbalanced burden to the industry. In simple terms the industry wants to know if some construction can be conducted in the spring without harming the juvenile fish. Fisheries agencies have agreed to reconsider their regulations in the context of additional studies. So, in this talk I will present some thoughts on risk assessment in general and the results of our study to assess the impact of pile driving on Snohomish River juvenile pink and chum salmon that migrate through the Navy Homeport construction site at Everett. The research, which is being carried out by the Fisheries Research Institute at the University of Washington, was planned and is supported in a joint effort including: the Washington Department Fisheries, National Marine Fisheries Services, U.S. Fish and Wildlife Service; General, Manson, and Hurlen construction companies, the Department of Transportation and a number of Puget Sound ports authorities. I will first briefly discuss the early life history of the juvenile salmon the regulations are designed to protect Second, I will outline the legal criteria required for risk regulation and some specific thoughts on how a reassessment of pile driving risk might be approached. With this basis I will report on our research and how it can be applied to a new risk assessment.

Jan 1, 1990

LARGE-SCALE production of zirconium by the Northwest Electrodevelopment Laboratory of the Bureau of Mines at Albany, Oreg., is an anomaly that justifies some explanation. The reduction of titanium tetrachloride with magnesium in an inert atmosphere, as perfected by Dr. W. J. Kroll before 1940, aroused renewed interest in zirconium, and in 1945 development work on this metal was initiated at Albany under Dr. Kroll's technical direction. Preliminary results were promising, and in February 1947 a pilot plant with a weekly capacity of 60 pounds of zirconium-metal sponge was put in operation. Shortly thereafter the Oak Ridge National Laboratory of the Atomic Energy Commission requested production of 1 ton of zirconium-metal sheet, with the provision that it have a low hafnium content. The Bureau of Mines was furnished with a. supply of Brazilian baddeleyite ore, containing less than 1 percent hafnium with respect to zirconium, from which was made about. 2,700 pounds of relatively low hafnium zirconium sheet of 0.080-inch thickness for test purposes. This was accomplished by melting zirconium sponge in a graphite crucible, hot-rolling the ingot in an iron sheath, and finishing by cold rolling. Concomitantly the Oak Ridge Laboratory developed a method for separating hafnium from zirconium; and, in cooperation with the Atomic Energy Commission and the Bureau of Ships of the Department of the Navy, a, larger pilot plant was erected to produce zirconium from very low hafnium zirconium tetrachloride furnished by the Commission. Pilot-plant work on producing zirconium tetrachloride from zircon sand and baddeleyite was discontinued. Production of zirconium sponge in the larger pilot plant of 500 pounds per week capacity was begun in June 1949.

Jan 1, 1956

By Christopher Jon Preston

This paper describes a type of ammonium nitrate (AN) produced in a patented experimental atomization/aerodynamic process. This AN exhibits outstanding properties for use as a main ingredient to a new family of AN-based commercial explosives. Micro-particle ammonium nitrate (MP-AN) is produced by atomizing either an 83% or 85% AN solution which has been doped with a two component surfactant NSol 1000 (NSol). NSol imparts some water-resistance as well as provides a means of increasing density and bulk strength. Increased detonation velocities, well in the range of emulsion explosives, can be achieved. The maximum manufacturing temperature is less than 100°C. The methodology has the potential of being environmentally friendly since any effluent can be recycled back into a make-up tank to be re-used by the closed loop method. The process has a small footprint.

Jan 1, 2015

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Jan 1, 2011

By J. Paraszczak

Water-powered jackleg rock drills, introduced recently in South African mines are reported to be more efficient, faster and more comfortable to operate than conventional pneumatic drills. A comparative testing of both drill types was performed in Quebec. Based on its results and time studies done in the mines, water-powered drilling has been reviewed with regards to drilling rates achieved, infrastructure needed, side effects, health and safety considerations. This study shows that the application of water-powered drills may help increase footage drilled and improve working environment, but under specific conditions. The examples of such applications are given in the conclusions.

Jan 1, 1995

By Thomas T., Read

SUGGESTIONS that existing schools give instruction bearing on the mineral industry, or that schools for that purpose should be established in the United States, began to be made early, and it would require too much space to catalogue them all. Some of the more important may be mentioned to indicate their general character. In the "advertisement to such parents as have now (or expect to have) children prepared to be educated in the College of New York," which appeared in the New York Mercury of June 3, 1754, Samuel Johnson, the first president of King's College, the predecessor of Columbia, said that it was the "design of this college to instruct and perfect the youth," among other things, "in the arts of Numbering and Measuring of Surveying, and Navigation and Geography. . . . and in the Air, Water and Earth around us, and, the various kinds of Meteors, Stones, Mines and Minerals, Plants and Animals; and in the knowledge of all Nature in the Heavens above us, and of everything useful for the Comfort, Convenience and the Elegance of Life . . . " Though the concept that natural science should be used to enlarge the bounds of human life was thus implicit at Columbia from the very beginning (John Stevens graduated from it in 1768, James Renwick in 1807, Horatio Allen in 1823, and A. W. Craven in 1829), it was only during the period of Renwick's professorship of Natural and Experimental Philosophy and Chemistry (1820- 1853) that much attention was given to applied science.* Among the Austin papers, published by the American Historical Association,2 there is a draft in Stephen F. Austin's handwriting of a proposed memorial from the legislature of Missouri to Congress, not only urging "the propriety and utility

Jan 1, 1941

By S. H. Ash

Tunnel driving is recognized as one of the most hazardous of occupations; this is a reflection of the high accident severity rates and resultant high compensation and similar costs in this industry. Most tunnels are driven by contractors who bid for the jobs, taking into consideration the prevailing industrial insurance rates at the time the bids are placed. After the bid is secured the contractor then attempts to complete the job at the minimum cost to himself. In a sense the accident-cost item is fixed for at least one year when a policy is secured. Time is generally an important factor not only for the contractor, but also for the insurance carrier and the assured. If the assured represents a private interest, the cost burden usually is ultimately placed on the general public which avails itself of the service contemplated; if the project is a governmental enterprise the cost burden unquestionably falls upon the general public involved and on the general tax payer. For these reasons it is of vital interest to the public that accidents not only be kept at a minimum as a humanitarian objective, but also because the accident-cost burden, too frequently not even realized and considered to the degree that it should be, can assume proportions that materially affect the cost of the enterprise. The basic industrial insurance rate for tunneling in California in 1932 contemplated an earned premium of 12.12 percent of the labor pay roll. The State has been particularly engaged in large construction enterprises, some of which involve high accident cost rates, notably structural-steel bridge building, which contemplates an earned premium of 19.65 percent of the labor pay roll. When this figure is compared with the much lower rates that apply to other industries it is apparent that a heavy toll in human wreckage is taken by such engineering projects, which must be viewed as monuments to human suffering as veil as to human achievement.

Jan 1, 1933

By Steve Kral

The Society for Mining, Metallurgy and Exploration’s origins can be traced back to 1871. This was when 22 Pennsylvania coal mining engineers founded the American Institute of Mining Engineers (AIME). The organization’s objective was to “promote the arts and sciences connected with economic production of the useful minerals and metals, and the welfare of those employed in those industries by all lawful means.” Metallurgy and Petroleum were added to the AIME name in 1919 and 1956, respectively. Divisions of AIME were formed throughout the following years in recognition of the increasing trend toward specialization among mineral industry engineers. At the time, SME’s divisions consisted of the Coal Division (1930, now known as the Coal and Energy Division), the Industrial Minerals Division (1935), the Mineral and Metallurgical Processing Division (1948) and the Mining and Exploration Division (1949). The Environmental Division was created in 1997.

Jan 1, 2007

By J. Cayouette

In 1995, Louvicourt mine started one of the first paste backfill operations in Canada. From 500 000 t in 1995, the annual paste backfill tonnage produced reached 800 000 t in 1999. The maximum throughput of the surface plant (including binders) is 3500 tpd with a final density of 75% to 76% solids which gives a slump of 15 cm to 17 cm. Following the start-up of the paste backfill plant, the backfill strength performance levels were well below the pilot plant’s predictions. The introduction of ferrous slag, laboratory tests on various binder ratios with or without additives, and the desliming of the tailings enabled us to optimize the mix and operation costs. Primary and secondary stopes are filled respectively with a paste containing 4.5% and 2% binders in a mixture of 20% cement to 80% ferrous slag. In certain stopes, the binder ratio may vary from 2% to 7%, but always in a ratio of 80/20. Six years after start-up, or 4.5 Mt of paste backfill later, this paper discusses the present operation and the major changes that have occurred over the years to optimize both the operation and the paste fill quality.

Jan 1, 2003

By Kenneth R. Sites

Under this program two tape recording and triggering systems were developed and delivered for use in the Bureau of Mines microseismic program. The systems are designed to improve the effectiveness of the Bureau owned Sangamo 3500 series and SABRE VI instrumentation tape recorders. The system is designed to capture random microseismic data, digitize and temporarily store these data, start the tape recorder; and then transfer the data to magnetic tape for permanent storage. The system is designed to pack data on tape such that the tape may be simply played back through galvo drivers onto an oscillograph such that a continuous series of analog records, with corresponding time of day information, are reproduced without excessive oscillograph paper waste or the need for the operator to search for valid events.

Jan 1, 1980

By Merle L. Bowser

The Bureau of Mines has developed a portable recording methanometer that utilizes the Bureau's methane sensor. The methanometer can operate continuously for at least 30 hours on small, sealed, rechargeable lead-acid batteries.

Jan 1, 1969

Tailings embankments can develop a high phreatic surface if the original design for the embankment does not include drainage facilities or if existing drainage facilities become ineffective. Subsequent raises can develop a seepage surface due to a high phreatic surface that can lead to stability problems. The U. S. Bureau of Mines amended contract J0100013 to initiate this study of horizontal drains in tailings embankments. This study developed a technique for determining the length of and spacing between parallel drains through the use of the finite element model UNSAT2. The analysis is based on the combined output of a vertical planar mesh and a horizontal planar mesh. The slot opening in the drain pipe and the length of the perforated section are determined from an analogy to water well design. The pipe diameter and gradient can be determined from Manning's equation. To the authors' knowledge, this is the first attempt at horizontal drain design using a finite element model. Additional research is recommended in this area.

Jan 1, 1982

By J. E. Matta

The methane gas emitted from coal samples collected from the conveyor belts dumping into silos was measured by the Bureau of Mines. Approximately 50 pct of the total gas desorbed into a sealed can within 1 week was released during the first 24 hours. No simple correlation between the gassiness of the coal stored and the methane concentration in the silo open space above the coal was found. This was probably because the gassier coals were stored in open-top Silos, which were better ventilated. Although the methane concentration in the open space above the coal pile was less than 1 pct for all 34 silos investigated, a methane measurement in the coal pile showed that high methane concentrations can exist. The methane released in the pile appears to accumulate and not liberate freely into the open space above the coal pile. Probably this gas is released during reclaiming operations, but further research is required to substantiate this claim.

Jan 1, 1978

By Teale E. O

The purpose of the present communication is to put on record the discovery, in October, 1916, in the Howqua district, of a new locality for the occurrence of phosphatic rocks in Victoria, and to give a preliminary description of its characters and geological occurrence. Owing to the great use of superphosphates for agricultural purposes in recent years in Australia, search has been stimulated for the discovery of local and workable supplies of phosphatic rocks. Phosphorus is an element very widely distributed in igneous rocks, usually in the form of the mineral apatite, and also occurs in sedimentary rocks and in soils as a detrital constituent. Under these conditions of occurrence, however, the amount of P 205 present in a rock or soil seldom approaches, and very rarely exceeds, 1 %. Very occasionally it occurs in such a concentrated form as to constitute workable deposits. In such cases they are usually of organic origin. Sometimes they occur as geologically recent deposits of guano or rock...

Jan 1, 1918

By D. Harrington

The experience of the past 2 years has demonstrated clearly that mine explosions with heavy loss of life can be prevented. The investigations of the Safety Division of the United States Bureau of Mines disclose that during the fiscal year 1934 there were only 28 deaths from mine explosions in the United States, and during the fiscal year 1935 there were 54 deaths, a very favorable reduction when compared with an average death toll of 265 from this cause during the 20-year period prior to 1929. Although the frequency of occurrence of explosions has not decreased greatly during the past 7 years, there has been a marked decrease in severity, indicating that the coal-mining industry is taking more effective precautions to prevent the spread of explosions. A number of large coal-producing States, which in past years have experienced numerous disastrous explosions, have been free from such disasters for continuous periods of as much as 5 years or even longer. A study of several hundred mine explosions occurring in the United States during the past 10 years or more indicates that the factors mainly responsible for these explosions are inadequate or defective ventilation and disregard of the hazards from explosive gas. Both of these factors are subject to control, and if controlled it is safe to say that deaths from explosions would be reduced to a negligible number as relatively few explosions are now initiated by dust.

Jan 1, 1936

By Peter Makuvise, Alain M. Bantshi

"The Mazowe Gold Mine is managed by Metallon Gold (Zimbabwe) and is situated in the west-central part of the Harare greenstone belt. Orebodies here generally comprise shear zones which are in-filled with gold-bearing sulphides and quartz. The mineralised zones are up to 1 m in width, have average grades of 4 to 5 g/t, and mostly dip between 10º and 60º to the north.Mazowe Mine is one of the oldest mines in Zimbabwe, and exploration and development in this region dates back to 1890, with over 1.4 million ounces of gold produced to date. Mazowe mine comprises two underground operations, Mazowe and the BSV sections. Ore is processed in a single plant which consists of conventional crushing and milling and carbon-in-leach facility.Baldmin Projects was awarded the contract for the design, construction and commissioning of the 60,000 tonnes per month plant at Mazowe mine in 2014 for the processing of sand and slimes tailings from previous operations at Mazowe mine. The average grade of the tailings is 1.1 g/t. The plant consists of feed preparation, grinding, flotation, thickening of flotation concentrate, and carbon in leach (CIL). A pump station for hydraulic mining of the slimes tailings dam also part of the plant.Key features of the Mazowe sands Plant are described and include:• Hydraulic mining of gold tailings dump.• Feed preparation section that includes a (W x L) 2.4 m wide x 4.8 m trash screen, 250 m3 surge tank, a cluster cyclones with 2 x 500 mm diam. Cyclone.• Comminution circuit designed for a bond work index range of 10-12 kwh/tonne. comminution circuit is constituted with 3 ball mills, 1.83 m diam. X 6.71 m Long, 280 kW.• Flotation circuit comprising rougher bank, scavenger bank and cleaner bank. Rougher Scavenger bank is constituted of 6 x 6m3 flotation cells and 3 x 30 m3 flotation cells and the cleaner is constituted of 3 x 6 m3 flotation cells.• Concentrate Thickening with 6 m diam. Thickener.• Concentrate CIL (carbon in leaching): CIL circuit is comprised of 7 tanks with 2 leach tanks and 5 Carbon in leach."

Jan 1, 2017

By Seoul National University, Ki-Ho Kim, Jong-Pyo Kim, Sung-Min Joo, Hee-Chan Cho, Hyung-Seok Kim

Aragonite was synthesized in addition of Mg2+ ion and SrCO3 seed by carbonation process, and the best condition and mechanism of the synthesis was studied by analysis of continuous pH change, ICP, XRD, and SEM. As MgCl2•6H2O addition increased, aragonite phase increased at condition of CO2 flow rate of 100 mL/min and stirring rate of 250 rpm. It was the dissolution of Mg(OH)2 that determined overall reaction time. As SrCO3 seed addition increased at 0.2 mole MgCl2•6H2O, the amount of aragonite increased and the aspect ratio was from 5 to 9. And it was thought that Mg2+ ion prohibited calcitetransformation of aragonite formed by SrCO3.

Jan 1, 2003

By José R. Parga

In some parts of the Comarca Lagunera with population of about 2.5 million people, situated in the central part of northern México, chronic arsenic poisoning is endemic and severe adverse effects attributed to As exposure have been reported. Lifetime exposure to arsenic will develop classical symptoms of arsenic poisoning such as skin pigmentation changes, gastrointestinal disturbances and neurological changes. There are several methods available for removal of arsenic from well water in large conventional treatment plants, however a very promising electrochemical treatment technique that does not require the addition of chemicals or regeneration is Electrocoagulation (EC). The EC operating conditions are highly dependent on the chemistry of the aqueous medium, especially conductivity and pH. In this study, Powder X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Transmission Mössbauer Spectroscopy (TMS) were used to characterize the solid products formed at iron electrodes during the EC process. This study will provide an introduction to the fundamental concepts of the EC method. Finally the results of this study suggest that the presence of maghemite and magnetite particles can be used to remove arsenic (III) and arsenic (V). In the field pilot plant scale study more than 99% removal of As species from groundwater is achieved.

Jan 1, 2005

By J. Davis, M. G. Reading

"INTRODUCTIONInternational Minerals and Chemical Corporation (Canada) Limited operates two potash mine/refinery complexes near Esterhazy, Saskatchewan. Annual production of approximately 4.2 million tons is sold in the United States and overseas in five grades according to size and quality.Ore grading 25% K2 0 equivalent is mined from a horizontal bed by continuous boring machines, crushed, and hoisted at 8 inches. The refinery operation consists of the eight basic steps shown in Figure 1. Particle sizes handled are similar to those experienced in other forms of mineral beneficiation: 8 inches to 100 mesh. The ore is crystalline and particles are angular. Fortunately the major mineral constituents, sylvite (KCl) and halite (NaCl), demonstrate relatively low hardness at 2 to 2.5.Therefore, while simple abrasion must be acknowledged, it is not a major problem except, of course, in circuits carrying magnetite.Corrosion, as represented by the classic equations of Figure 2, occurs in all its various forms."

Jan 1, 1983

By Michael S. Miller

In 1987 and 1988, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 3,100-acre Borah Peak Wilderness Study Area (10-047-004) and a 708-acre parcel adjacent to the north in order to evaluate their identified mineral resources. The study area is located in Custer County, ID, about 18 mi northwest from MacKay. The study area lies along the western foothills of the Lost River Range and is underlain by quartzite, sandstone, shale, argillite, dolostone, and limestone. The Lost River fault, a major active fault, lies along the length of the study area. Large alluvial fans spread out from valleys originating east of the study area.

Jan 1, 1989