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By Andres Vikdahl

The Rönnsktär smelter has recently undergone a series of technical and operational changes. This changes are caused by our own will to remain and gain in competivety and to adapt to the ever changing surroundings. To be able to remain competitive in surrounding with high wage costs, high inflation and high environmental standards thorough cost management is needed. The Swedish economic policy in the beginning of the 80'ies consisted amongst other things of two devaluations. The exchange rate of the Swedish Krona was reduced with approximatively 25 %. This boosted the profits of our export industry, some even believed we entered the land of milk and honey ... And working in this promised land where everything turns into profit it is very difficult to be careful and restrictive with your spendings. Apart from some healthy and fruitful investments we allowed ourselves yearly steady increases in salary for ever reduced number of worked hours and we of course employed more people. Inflation rates went up and so did property prices. In 1986 finally reality catched up on us. Reality in the form of too high costs started to hit Swedish export industry 5-6 years after the big devaluations. Furthermore the high inflation rate also hit the domestic industry a couple of years later. Together with other important factors Sweden faced a severe home-made recession in the beginning of the 90'ies. With this background we now report and analyse our smelter's performance and operating results, shown in fig 1 The main constrictions on smelting and refining at Rönnsktär are today: * Income restrictions by governmental production level Limit * Throughput resmctions by governmental emission limit * High capital costs in the aftermath of Swedish high inflation in the recent decade * Low work force turnover Below we will illustrate how we tackled with these issues along the following lines: * People * Quality * Technology

Jan 1, 1993

By E. P. Ferrero

Analyses of 38 crude oil samples from 25 fields in Algeria, Libya, and Nigeria are presented in this report. The 38 crude oils are listed alphabetically by country and field. Also shown are the geographic and geologic sources of the samples analyzed, the companies that supplied the samples, the general characteristics and analytical and computed data, and the production for the fields from which the samples were obtained.

Jan 1, 1966

Rock property tests were performed on NX-size diamond drill core from the roof, floor, and coal from the longwall mining section of Federal No. 2 mine, West Virginia. The purpose of these tests was to determine the engineering properties of the various strata as part of a ground control study of the longwall operation. The following tests were performed: 1. Uniaxial compressive strength, Young's modulus, and Poisson's ratio 2. Triaxial compressive strength 3. Brazilian tensile strength 4. Modulus of rupture 5. Specific gravity Thirteen boxes of core delivered to the University on April 1, 1974 were identified as follows: 2 PTR 1 -2 boxes of roof rock 2 PTF 1 -2 boxes of floor rock 2 PTR 2 -2 boxes of roof rock 2 PTF 2 -2 boxes of floor rock with approximately 3 ft of coal in Box 2 (designated 2 PTC 2) 2 PTR 3 -2 boxes of roof rock 2 PTF 3 -2 boxes of floor rock 1 PC 5 -1 box of coal

Jan 1, 1976

By H. H. Schrenk

One phase of Bureau of lines work in health and safety is promotion of the use of safe, satisfactory, and reliable respiratory protective devices. To insure that devices embodying these features will be available the Bureau has established schedules of minimum requirements for oxygen breathing apparatus, gas masks4/, supplied-air respirators (hose mask, air-line respirators, and abrasive blasting helmet hoods, or masks)5/, and dispersoid (dust, fume and mist) respirators6/. Approval test, of oxygen¬-breathing apparatus are conducted by the Safety Division; approval tests of other types of respiratory protective equipment are conducted by the Health Division. These divisions comprise the Health and Safety Branch.

Jan 1, 1941

By Hyu-Soung Shin

This study is concerned with the characteristics of the behavior of steel-concrete composite drilled shafts, a material that is used for large bridge foundations, and especially for weak submerged ground conditions. Depending on the loading or boundary conditions considered, the behavior of foundation will vary. The bearing capacity of steel-concrete composite drilled shaft is influenced by initiation and propagation of fractures along the interface between steel casing and filled concrete. The interface effect is taken into account with the following two simplified cases: (1) detached model with free interface (no shear stiffness of interface) between concrete core and steel casing, (2) confined model by an upper steel cap with free interface. In the confined model, it is intended to have an unified behavior of composite shaft between concrete core and steel casing but there is interface between them. Intensive numerical studies have been undertaken to investigate detailed behavior of the composite shaft. In this study, 3-D finite element analysis is employed. Ground conditions typical of those encountered for the design of drilled shaft under water are considered affecting the behavior. Also, an attempt is made to generate possible combinations of the loads which have been considered in fields. Detailed characteristics of the stress and displacement distributions are evaluated to understand the mechanisms of composite shafts.

Jan 1, 2007

For years traditional optical microscopic techniques have been used successfully to carry out mineralogical studies on processing products. Essential information could be obtained by supplementing microscopic data with X-ray powder diffraction data, chemical analyses, etc. However, most of the time the mineralogists working on plant related issues, would supply qualitative information to the metallurgists, due to quantification not being possible in the available time. Since the late-80s, the use of semi-automated to automated techniques for mineral quantification has impacted positively on the use of mineralogy for optimising processing plants. Rustenburg Platinum Mines (now Anglo Platinum) were the first mining company to purchase a Qem*Sem in 1987. With the success achieved in quantifying the minerals in the concentrator streams of the Rustenburg Platinum operations, a second instrument was purchased soon after. These instruments have proven invaluable tools in understanding the flotation behaviour of the sulfide and gangue minerals in the various reefs of the Bushveld. Restrictions in the resolution of these earlier instruments, as well as the time involved in searching for and correctly identifying the fine-grained platinum-group minerals (PGM), meant that these investigations focused on the deportment of the more abundant base metal sulfides, rather than on the actual PGM. The Mineral Liberation Analyser (MLA), which became available in the late 1990s, was well suited to detect and analyse minerals occurring in trace amounts such as the PGM. Anglo Platinum was the first mining company to purchase such an instrument and now has fourteen systems operating at the AR Crown Mines site. One of the applications of these systems involves the study of feeds, concentrates and tailings from the various concentrators on a monthly basis. These routine investigations provide information on a variety of mineralogical parameters, including liberation, association, and grain size. Results are used to emphasise areas for improvement, and specifically underline those areas where improvements will have the most impact on recovery. After new or different technologies have been implemented, mineralogical characterisation of the different process streams is an essential component in the assessment of the impact of these changes on flotation performance. In addition, the knowledge is databased for future reference to draw trends across the various concentrators around the Bushveld complex, and is also used for comparative studies when plants experience high losses to tailings. Due to the success of these investigations the question was posed whether it was possible to obtain data on a daily basis, as compositing samples could hide the impact of daily events. Although the instruments currently used are suitable for a research environment, these are not ideal for mine-site implementation. For that reason Anglo Platinum, together with FEI embarked on a development program to develop a system that can be implemented on-site to measure the important mineralogical characteristics on a daily basis. Important requirements for such a system include time-to-data, ease of use and regular quality control. Highlighting some results from concentrator studies, the presentation will review the progress on the development of automated mineralogical techniques for fast, automated mineral measurements. This is an abstract only. No full paper was prepared for this abstract.

Sep 13, 2010

By Joel A. Hunt

The Bunker Hill Mine, located in north Idaho, consists of over 150 miles of passageways within highly fractured and faulted Precambrian metamorphosed rocks. The Bunker Hill Mine was at one time a major producer of lead and zinc; currently it is on inactive but maintained status. Ground water moving along flow paths that have been disturbed by mining reacts with pyrite and oxygen to produce acid water within the mine. Discharge of this acid water averages more than 5 cubic feet per second, with an average zinc concentration of 160 mg/L and pH of 2.8. Treatment of this acid mine drainage is required by the National Pollutant Discharge Elimination System (NPDES). Cessation of all underground activities at the Bunker Hill Mine will not terminate the production of acid mine drainage. Reclamation alternatives that could either reduce the quantity or Improve the quality of the drainage upon mine closure are highly attractive. This project is directed towards delineation of reclamation alternatives based upon an understanding of the characteristics of ground water recharge near the mine. A variety of field techniques were used to identify areas of rapid infiltration and to investigate the ground water flow system associated with the upper portion of the mine in a portion of the Milo Creek drainage. These techniques include Installation of piezometer nests, dye tracing, surface resistivity, dye dilution, spring surveys, and hydrochemical analyses. Sites of direct Infiltration into the mine have been located. These include mine workings directly below perennial streams, intersections between streams and faults, and a caved area adjacent to an ephemeral stream. Results of these investigations indicate that recharge through these sites is not as rapid as suggested by previous studies. Inflow to the underground workings from the ground water flow system around the margin of the mine may account for more mine water than sites of direct infiltration. Recharge control at areas of direct infiltration could result in a net decrease in the quantity of acid drainage from the Bunker Hill Mine. Locations suggested for recharge control are West Milo Creek above the Guy Caving Area, the intersections of the Cate Fault with South Milo and Milo Creeks, and an area of Milo Creek below the Milo Creek Dam that overlies shallow mine workings.

Jan 1, 1984

Humankind's interest in measurement of human physical strength probably dates to the first humans. At that time, life was truly a struggle in which the fittest survived. To a great extent, fittest meant strongest. Interestingly, current interest in human physical strength in the workplace stems from 1970-1980s vintage research demonstrating that persons with adequate physical strength are less likely to be injured on physically demanding jobs. Survival in many modem workplaces may still be a case of survival of the strongest. There is, however, a flip side to this issue - that persons with limited strength are more likely to be injured on "hard" jobs. To address this problem, we can apply what we know about physical strength to job design. "Hard" jobs can be redesigned to be within the physical strength capability of most people. Since physical strength is important to these jobs, we must find ways to quantify it through testing. This publication concerns human physical strength testing. Its purpose is not to recommend any particular type of testing, but rather to describe the types of testing available and their uses. It is up to each individual user of strength testing to decide which testing technique is most appropriate for his or her particular application. This booklet discusses four types of strength testing: isometric, isoinertial, psychophysical, and isokinetic. Human Strength Before describing the different types of strength measurement, we must define the term "strength" and explain the concept of strength measurement. Strength is defined as the capacity to produce force or torque with voluntary muscle contraction. Maximum strength is defined as the capacity to produce force or torque with a maximum voluntary muscle contraction.(1,2) These definitions include some key words that must be explained. A voluntary muscle contraction is "voluntary." When a person's physical strength is measured, only the effort the person willingly puts forth at the time is measured. Thus, when we test a person's "maximum strength," we are not measuring his or her actual maximum, but some lesser value representing what he or she is comfortable expressing at the time with the existing equipment and environmental conditions. Interestingly, when researchers startled persons being tested (e.g., by setting off a starter's pistol behind them), they have found significant increases in measured strength.(3) It has been hypothesized that the lower strength displayed during normal testing provides a margin of safety against overloading and damaging muscle tissue. The test equipment and the tested person's familiarity with the process also influence the "voluntary" strength output. The interface between the tested person and the test equipment is particularly important. A poorly designed interface induces localized tissue pressures that vary from uncomfortable to painful. In this situation, testers are measuring voluntary discomfort tolerance - not strength. It is important for strength researchers to keep the "voluntary" nature of their data in mind when they are designing their equipment and protocols.

Jan 1, 1998

By F. A. Rutledge, B. S. Webber, J. M. Moss

"INTRODUCTION The United States, with its vast resources of relatively low-grade zinc been the world's leading producer of zinc -metal for many years. The expanded zinc production during the period, 1939-44, inclusive, was induced by favorable premium prices and has depleted the known ore reserves in the United States. The 1943-44 rate of zinc production cannot long be maintained in the United States, especially if premium prices are removed. Domestic zinc reserves, have been depleted to such an extent that it is doubtful if our mines will again be able to completely and continually fulfill the needs of this country.The Bureau of Mines, anticipating a postwar consumer demand for 550,000 to 750,000 tons of slab zinc and an additional 100,000 tons for use in paints and chemicals, sent two engineers to Sedanka Island in July 1945 to investi¬gate the deposits near Biorka Harbor.ACKNOWLEDGMENTIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion the Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director."

Nov 1, 1946

By L. J. E. Hofer

"INTRODUCTION This paper is riot to be considered a complete survey of data on carbides; it is only an attempt to correlate the more reliable of the existing data of interest in connection with the Fischer-Tropsch synthesis, and its purpose is to guide future experiment and thought.A general review of the literature on the Fischer-Tropsch synthesis will be published in the near future as a chapter by H. H. Storch for a book entitled, ""The Chemical Utilization of Coal,"" edited by H. H. Lowry. This chapter covers the literature up to l9). It is planned to bring the review up to date in a comprehensive bulletin on Synthetic Liquid Fuel Processes to be completed during the next year. ACKNOWLEDGEMENTSThe author discussed the significance of the data with several members of the Physical Chemistry and Hydrogenation Section.THE PREPARATION OF CARBIDES OF IRON, COBALT, AND NICKELThe reaction of carbon monoxide with Fischer-Tropsch metals was first studied in a quanitaive way by Bahr and his coworkers. The contents of their first papers, 3/ 4/ 5/ which deal with the action of carbon monoxide on nickel, cobalt, and iron, will be described in the following paragraphs, together with the pertinent results of other investigators."

Jul 1, 1944

By S. Kraemer

Consumption of plastics has been growing in both the U.S. and world markets since the mid-1930s. This growth is due to plastics being used to make new products and as a replacement material for existing products. This paper develops an understanding of the replacement process by looking at the use of plastic, specifically PVC, in the construction pipe industry. History details the growth of the plastics industry and a discussion of the material selection process indicates the advantages and disadvantages of plastic pipe. Analysis shows that the use of plastic, as an alternative material for pipe, is having a significant effect on the cast iron, copper, clay, and steel industries. For the purpose of understanding the replacement process, three example residential systems were examined with a lifecycle cost analysis being performed. PVC was the material of choice in 1988 for all systems. Even though disposal cost was the one area where PVC was not the most cost effective, disposal costs were not sufficient to offset the overall advantage of using PVC on an economic basis. That plastic competes effectively with other materials, in terms of material properties and cost, indicates that further work should be performed to understand the impact plastics have on other material markets.

Jan 1, 1991

By A. Aitio

Sustainable development is one of the central themes of the work of the World Health Organization; chemical safety is one of its important components. For more than 25 years, WHO has had specialized units for assisting member countries in dealing with their problems in chemical safety. For one of the units involved, International Programme on Chemical Safety, a reorientation is in progress to make best use of existing resources, and to prioritise the work to optimally correspond to the needs of the member countries. The risk assessment work of IPCS, and specifically, the work on chromium and chromium compounds, are discussed.

Jan 1, 2004

This study relates to continuous face haulage systems in underground coal mines, and was performed by Joy Manufacturing Company for the U. S. Bureau of Mines under the Bureau of Mines Contract No. HO 242025. The effective starting date for this work was June 14, 1974. There were two main reasons for making this study, the first being to find a safer system to move coal away from the face than the currently predominant shuttle car system, and the second being to seek ways to advance the state-of-the-art of continuous face haulage as a means of increasing coal production.

Jan 1, 1975

By H. Do

In flotation, hydrophobic particles are selectively collected by air bubbles, and the bubble-particle aggregates enter the froth phase. However, less hydrophobic particles drop off from the froth phase, while more hydrophobic particles are recovered. Thus, the froth phase provides an important cleaning mechanism. In the present communication, the froth-phase recovery process has been modeled by considering particle retention times and the carrying capacities of bubbles. The model predictions are compared with the experimental data reported by Seaman et al. (2006). The results show that the froth-phase recovery varies with particle size, particle hydrophobicity, and bubble coarsening.

Jan 1, 2008

By E. W. Dean

This report on the physical and chemical properties of typical crude oils of Oklahoma is the sixth in a series of preliminary chapters of a bulletin covering the producing districts of the United. States. Preceding reports* may be obtained on request. The details of the methods used in this survey in collecting samples, making laboratory tests, and interpreting results are discussed in the first three papers. If any errors or omissions are noted by readers, it is hoped they will be brought to the attention of the Bureau of Mines for correction before the appearance of the permanent report. Samples of Oklahoma crudes analyzed in this report were taken from those fields representing the major production of the State. The Oklahoma Geological Survey designates 172 different oil and gas fields in the State, S1 being in Osage County, 14 in Tulsa County, 14 in Okmulgee County, 9 in Washington County. The list of samples collected by the Bureau of Mines represents only 5 fields in Osage County - Bigheart, Burbank, Hominy, Osage Junction, and Pershing - yet these samples, together with those from adjoining fields, are representative of nearly all crude produced in the county. The sample 'from the Pershing field, for example, is representative of the crude produced in several fields in that part of the county - such as Nelagoney, Pawhuska, Wyomona - and the sample from the Skiatook,

Jan 1, 1922

By R. O. Dannenberg

The Bureau of Mines conducted laboratory investigations with the objective of developing an alternative process for recovering cobalt and copper from complex sulfide concentrates. Processes currently used depend largely upon precipitation techniques to remove impurities and recover cobalt from sulfate liquors prepared by oxidative pressure leaching of the sulfide concentrates. The Bureau conducted bench-scale research on a process for treating cobaltite concentrates, comprising (1) oxidative pressure leaching, (2) jarosite precipitation followed by H202 oxidation and pH control to remove iron and arsenic, (3) copper solvent extraction with a mixed hydroxyoxime-amine extractant, (4) copper electrowinning from recirculating acidic strip liquor, (5) selective cobalt extraction from copper solvent extraction raffinate with a phosphinic acid extractant, and (6) electrowinning of cobalt from a recirculating weak acid strip liquor. Overall cobalt and copper recoveries were 91.7 and 84.1 pct, respectively. Electrowon products assayed 99.8 pct Co and 99.89 pct Cu.

Jan 1, 1987

By L. E. Beverage, K. L. Johnston

This paper will address methods for minimizing liability and protecting materials from disclosure as result of self- evaluative audits and internal investigations. Specifically, the paper will cover the role of counsel in the investigative process and how best to design and conduct internal investigations to minimize the development of problematic material and disclosure of information. The paper will also address the extent of privileges that may be relied upon to protect materials and information from disclosure. These include the attorney-client privilege, the self-critical analysis privilege, and the attorney work product privilege. These privileges are qualified and understanding the limits of their coverage is essential to minimizing liability.

Jan 1, 2001

By B. Boberg

Annual requirements of uranium to fuel the 441 currently operating nuclear reactors in the world is 170 million pounds U3O8 (65,385 tonnes U). 2005 global production was 108 million pounds (41,595 t U), of which only 2.7 million pounds U3O8 (1,039 t U), was produced from US uranium deposits. US nuclear utilities represent 26% of the global nuclear capacity but only obtain 2.5% of their supply from US uranium mines. Since 2002 annual global production increased from 93 million pounds U3O8, a 15% increase and the US production increased from 2.3 million pounds to 2.7 million pounds, a 17% increase. Reasonably Assured Resources (RAR) of 12,332 million pounds U3O8 (4.7 million t U) are reported from a wide variety of countries and types of uranium deposits. This RAR suggests that there are significant global uranium resources potentially producible at a price of $50 per pound U3O8 ($130 per kg U). Table 1 shows the distribution of global uranium resources. This table, prepared from historic data maintained by the World Nuclear Association, does not include some areas of the world that are currently considered to contain significant resources of uranium such as Mongolia. Table 1 suggests that the United States contains the fourth largest uranium resource in the world with 890 million pounds U3O8, behind Australia, Kazakhstan and Canada in resources that are producible at a price of $50 per pound U3O8 ($130 per kg U). Within the US, the states that demonstrate the greatest amount of uranium resource are Wyoming, New Mexico, Texas and the Four Corners Area of Arizona, Colorado and Utah.

Jan 1, 2007

By Richards RG, Cross MS

The development of alluvial mining, processing systems and associated gravity separation technology over the last 30 years is largely linked to the mineral sands industry. Attention has been focussed on Australia in these areas of mineral resource development and technological Advancement.

Jan 1, 1986

The purpose of this study is to formulate practical guidelines for active underground mining in close proximity to water bodies. This was accomplished through systematic completion of three phases of study: I) Collection and Documentation of Data; II) Application of Existing Guidelines to Case Histories of Previous Inundations; and III) Development of Recommended Guidelines for Underground Coal Mining Near Bodies of Water. Phase I of the study involved a worldwide data collection effort designed to obtain foreign and domestic guidelines for mining near water bodies, and accident records and case histories of accidental mine inundations. Within Phase II, existing guidelines were categorized and classified and then evaluated as to their effectiveness in precluding past inundations had they been in effect at the time of inrush. Advantages and disadvantages of existing guidelines were defined. Drawing on the broad data base established in previous study efforts, Phase III was directed at development of viable guidelines to promote the greatest possible coal extraction while precluding accidental mine inundation. Two levels of guidelines are presented; Level I Guidelines require little or no subsurface exploration on the part of the mine operator, while Level II Guidelines recommend various testing and investigative procedures to permit greatest possible mineral extraction. This report presents findings and conclusions of the study.

Jan 1, 1976