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By William F. Hahn

It is a pleasure to speak to this group about special crusher installations which are in the bauxite and phosphate rock processing industries. The installations to be discussed demonstrate the variety of conditions, materials, and results desired which must be evaluated before a selection is made from the specialized crusher technology available today. Those of you who are closely involved with phosphate rock and phosphate products processing will find some of this information a bit interesting and perhaps alien to your own descriptions or every day references. It is given from a "crusher" manufacturer's viewpoint and therefore is infused With our flair and language. General features of six (6) different crushers will be shown in cross-section With slides and will be discussed in the same order.

Jan 1, 1978

By Kenneth K. Landes

Lake stone is a term currently applied to chemical and metallurgical grade limestone or dolomite that is brought down Lakes Michigan and Huron by large cargo vessels, mostly self-unloaders. This stone comes from 5 quarries, all in Michigan and all steel company owned. The volume in 1973 was over 34 million tons. The primary reasons for the large volume are the quantity and quality of the stone available, and the low delivery costs to lower lakes markets. The source rocks are Silurian and Devonian limestones and dolomites of exceptional purity. The regional dip of these formations is 50 to 60 feet per mile southerly toward the lowest point in the Michigan structural basin, which is near the center of the Southern Peninsula. Two of the 5 quarries, both high calcium limestone sources, are on Lake Huron in the northeastern part of the Southern Peninsula. The other three are in the Northern Peninsula; one at the northern end of Lake Michigan, and two on northern Lake Huron. The western quarry is in limestone, the other two in dolomite.

Jan 1, 1975

By J. B. Janus

This report continues a series of analyses of coal samples made by the Bureau of Mines in connection with the yearly purchase of several million tons of coal for various Government agencies. Listed are the analytical data on the composition and quality of tipple and de livered samples of coal collected during fiscal year 1974.

Jan 1, 1975

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. By agreement with the American Petroleum Institute, identification of the items is confidential. It presents analytical data for 4,954 samples, representing the products of 93 companies. The samples were collected during December 1955, January and February 1956. As in previous surveys, the gasolines covered by this survey include those from both large and small suppliers. The data were obtained by laboratories of various refiners, motor manufacturers, and chemical companies and submitted to the Bureau of Mines for compilation. A list of the National Motor Gasoline Survey reports published during the post 10 years is given on page 5.

Jan 1, 1956

By Charles W. Schwartz, Subash Kolluru

INTRODUCTION Creep of rock in situ, like most rock mass behavior, will be largely governed by the behavior of the natural discontinuities -- bedding planes, faults, and joints, in particular, Several past studies have investigated various aspects of the time-dependent deformation of rock discontinuities; examples include Amadei and Curran (1980), Engelder and Scholz (1976), Johnson (1975), Kaiser and Morgenstern (1979), Solberg et al. (1978), and Wawersik (1974). These studies have provided much insight into the general phenomenon, but they have also produced some inconsistent conclusions and left many unanswered questions. This paper will attempt to shed some light on one of these questions: What is the influence of stress level on the creep of unfilled rock joints? The discussion will follow a two-part approach to the problem: (1) laboratory creep experiments on small scale jointed specimens, (2) a simple theoretical mechanism to explain, at least in qualitative terms, some of the results from the experimental program. EXPERIMENTAL PROGRAM Uniaxial creep tests were conducted on intact and jointed samples of a specially formulated gypsum plaster "synthetic rock." Synthetic rock materials have several advantages over natural rock for long-term creep testing: (a) higher creep rates, (b) lower strength and therefore lower loading requirements, (c) simpler specimen preparation, and (d) more controlled and consistent properties. Gypsum based plasters have been used previously in studies of short-term strength and deformability of jointed samples (Patton, 1966; Einstein and Hirschfeld, 1973). Furthermore, Williams and Elizzi (1977) demonstrated that natural gypsum, at least, creeps in a manner similar to that of most other creep-susceptible natural rocks.

Jan 1, 1982

By F. Varley

Researchers from the National Institute for Occupational Safety and Health (NIOSH), in cooperation with mine operators, conducted a study of heat stress exposures among mine rescue workers in underground mines. Mine rescue workers face extreme heat loads as they enter hot and poorly ventilated environments, particularly when they are wearing breathing apparatuses. The burden of wearing a closed-circuit breathing apparatus (CCBA), the inability to drink fluids for extended periods of time, and the potential for ventilation disruptions and fires combine to increase the risk of heat illness during a response to an emergency. In this research, ambient environmental conditions and heat strain indicators were measured using conventional ventilation monitoring tools during mine rescue training exercises. Heat strain was measured with an ingestible temperature-sensing pill that measured core temperature continuously. In addition, a heart-rate monitoring chest strap was used to indicate physical strain resulting from physical activity and heat. Both core temperature and heart rate data were transmitted to a remote recorder worn by a rescuer and time-stamped. Team activities were also observed to determine the contribution of work rate to a person’s total heat load. The effectiveness of several engineering controls, such as cooling the air inhaled by rescuers through an apparatus, wearing cooling vests, and supplying water through the CCBA masks, were investigated. Administrative controls, such as limiting the duration of exposure and controlling the work rate through forced-rest regimens, were also evaluated. Results to date are discussed, and tools for evaluating team condition and estimating the length of time it would be safe for rescuers to work are proposed.

By F. Varley

Researchers from the National Institute for Occupational Safety and Health (NIOSH), in cooperation with mine operators, conducted a study of heat stress exposures among mine rescue workers in underground mines. Mine rescue workers face extreme heat loads as they enter hot and poorly ventilated environments, particularly when they are wearing breathing apparatuses. The burden of wearing a closed-circuit breathing apparatus (CCBA), the inability to drink fluids for extended periods of time, and the potential for ventilation disruptions and fires combine to increase the risk of heat illness during a response to an emergency. In this research, ambient environmental conditions and heat strain indicators were measured using conventional ventilation monitoring tools during mine rescue training exercises. Heat strain was measured with an ingestible temperature-sensing pill that measured core temperature continuously. In addition, a heart-rate monitoring chest strap was used to indicate physical strain resulting from physical activity and heat. Both core temperature and heart rate data were trans-mitted to a remote recorder worn by a rescuer and time-stamped. Team activities were also observed to determine the contribution of work rate to a person’s total heat load. The effectiveness of several engineering controls, such as cooling the air inhaled by rescuers through an apparatus, wearing cooling vests, and supplying water through the CCBA masks, were investigated. Administrative controls, such as limiting the duration of exposure and controlling the work rate through forced-rest regimens, were also evaluated. Results to date are discussed, and tools for evaluating team condition and estimating the length of time it would be safe for rescuers to work are proposed.

Jan 1, 2004

By M. Dupuis

It has been previously demonstrated [l] that there is no obvious thermal balance related issue limiting the size of a Hall-Héroult cell. Yet, it is well known that a forced-air sidewall cooling system is part of the AP50 cell design [2], In the present study, the authors analyze the impact of thermal loading on the mechanical deformation of high amperage cell potshells. The effect of adding cooling fins or a forced-air sidewall cooling system is then assessed.

Jan 1, 2005

By Thomas J. Peters

The Goat Rocks RARE II further planning areas contain no known mineral resources and have very low mineral potentials. County mining records show only one mining claim area; however, no mineralized material was found at the described location. Andesite suitable for building stone may be present, but similar material can be quarried more economically elsewhere. Several anthracite coal prospects are near the area, but the likelihood of finding an economic deposit of coal or other fuel is very low.

Jan 1, 1981

By W. J. Wenger

Colorado has been producing petroleum since 1863 but only recently has become a major oil State. The first well was drilled on Oil Creek near Florence, but out-put was relatively small until discovery and development of the Weber sandstone reservoir at Rangely. Oil was discovered in the Weber sandstone in 1933, and the reservoir was developed after 1940, bringing Colorado, in 1949, to 11th place among the 48 States as an oil producer. Colorado's output increased further because of the discovery and development of many fields in the Julesburg Basin since 1949 By 1954 Colorado was in ninth place and maintained that position through 1955.4/ Between 1946 and 1951, Colorado's oil production more than doubled, while the total United States production increased only 25 percent. It seems probable that production will continue to expand in Colorado for many years. This report presents analyses of 92 crude oils from 73 fields representing 90 percent of the production in 1955. Abridged analyses are listed for easy comparision, and complete analyses arc given in the appendix. Oil samples were collected for study from many different sources. Although many of the newer fields were not sampled, their oils probably are very similar to those from corresponding formations that were studied and tabulated.

Jan 1, 1957

By C. R. Fast

In order to evaluate the ability of a Hydrafrac treatment to effect a sustained increase in well production, data were accumulated on the first 65 wells in 26 fields treated by Stano-lind. Since these data were obtained from such a large number of fields, it is felt that individual well or reservoir characteristics do not affect the overall picture, as might be the case if the study were made in one field or one group of wells in a field. These data are tabulated in Table I and plotted on Figs. 1 and 2. An analysis of Fig. 1 shows that at the end of six months, 75 per cent, or 45, of 60 wells on which data were available showed a sustained production increase. At the end of two years, data were available on 25 wells. Of these, 15 wells, or 60 per cent, showed a sustained production increase. At the end of three years, 55 per cent, or 10, of 18 wells had a production rate greater at that time than before Hydrafrac treatment. The lack of information on additional wells at the end of the third year is primarily a result of the small number of treatments conducted in the early stages of field application

Jan 1, 1952

By Harold Margolin

The Ti-Al system certainly merits the investigative attention it has been receiving and this latest contribution by Blackburn is therefore to be welcomed. The titanium-rich end of the phase diagram shown here, as well as the diagram by crossley,17 Clark et a1.,18 and Tsujimoto and Adachi,29 reveal no other intermediate phase than Ti3A1, although a previous work by Ence and Margolin20 had reported an additional intermediate phase. Since then, Buerger Precession pictures of single crystals of 10.5, 11.5, and 12.5 wt pct A1 were made at New York university21 and the extinctions were found to be typical of a D6h a Ti structure. Some superlat-tice spots and/or streaks suggesting the presence of an Mg3Cd structure, i.e., Ti3Al, were also found. Since these specimens had been quenched from the y region20 and had revealed a Ti, it was concludedz1 that y does not exist and the structures interpreted as m + y could not be so considered. The absence of normal two-phase behavior in these structures had been indicated in the paper. Accordingly, the two-phase region y + 6 becomes a + Ti3Al and there is some agreement between the results of Blackburn and of Ence and Margolin20 as to both shape and existence above 900°C of an a + Ti3Al field. Crossley 17 proposed that Ti3Al is a line compound which decomposes congruently at 900°C. It is difficult to discount entirely the fact that clear two-phase structures, varying in amount with position in the two-phase field, could be detected above 900°C by Ence and Margolin.20 Precipitation during quenching could not have been so regular and the twin-phase syndrome17 does not apply. The heat treatment and quenching technique was essentially the same as was used by Crossley, whereas Blackburn, who used a rapid quenching procedure, also showed a two-phase a + Ti3A1 field above 900°C. If the two-phase field exists above 900° C, it is easy to picture a two-phase field which could account for the data of Crossley below 900°C without invoking a line compound existence of Ti3A1. All that would be necessary would be an 0 + Ti3Al/Ti3Al boundary which curved sharply to higher aluminum contents below 900° C. It is clear that the controversy must be solved by techniques which obtain data at elevated temperatures without quenching. It is conceivable that the difference in width of the a + Ti3N fields reported by Blackburn and by Ence and Margolin is due to the longer annealing times used by the latter investigators. The criterion for establishment of equilibrium in our work20 was the

Jan 1, 1969

By O. C. Blade

This report on the properties of aviation gasolines and aviation jet fuels produced in the United States during 1956 was made under a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. Analytical data are presented for 120 samples of aviation gasoline and for 38 samples of aviation jet fuel. The analyses were made on samples typical of the manufacturers' 1956 production in their laboratories and the results submitted to the Bureau of Mines for compilation. The products of 20 manufacturers of aviation gasolines and of 17 producers of aviation jet fuels are represented.

Jan 1, 1957

This consolidated index covers all publications of the Institute for the years 1926 through 1935. The following list indicates subjects of volumes and gives numbers or abbreviations used to designate them. TRANSACTIONS VOLUME *G26. Petroleum Development and Technology in 1925 (Published in 1926). *G26. Petroleum Development and Technology in 1926. *E27. Institute of Metals Proceedings. 73. Nonferrous Metallurgy, Milling and Concentration, Nonmetallic Minerals, Institute of Metals and Iron and Steel. [ ]

Jan 1, 1936

By C. H. Bloomster

This study estimated (1) radon and radon daughter emissions from underground uranium mines; (2) the reduction in radon that would be released to the surface by using control techniques such as bulkheads, sealants, backfilling, and positive pressure ventilation; (3) the cost for radon and radon daughter removal from total exhaust air; and (4) total radon and radon daughter discharge for lower occupational exposure limits. For 13 large underground uranium mines, estimated yearly radon emissions from each mine ranged from 900 to 3,400 Ci. The estimated age of air emitted from the mines ranged from 11 to 37 min. Potential radon removal methods for the total mine exhaust were evaluated. The cost of these methods was prohibitive. Diurnal and seasonal changes may affect radon emission over short periods of time, but do not affect the total emissions over the long run. Radon and radon daughter emissions would be little changed by increased ventilation requirements needed to achieve lower occupational exposure limits. The concentrations in the exhaust would be lower, but the total release would be the same

Jan 1, 1984

By Spencer S. Shannon

This chapter is concerned with the uses, geology, exploration, evaluation, preparation for markets, and future of 90thorium and 39yttrium, along with 14 rare-earth elements. The rare-earth metals or lanthanides were divided into three categories by Berzelius. The cerium subgroup is comprised of 57lanthanum, 58cerium, 59praseodymium, 60neodymium, and 62samarium. 61Promethium does not occur naturally. The terbium subgroup includes 63europium, 64gadolinium, and 65terbium. The remaining lanthanides are placed in the yttrium subgroup. Strictly speaking, yttrium is not a rare earth. Because the properties of yttrium resemble those of heavy rare earths, its name has been used as a designating adjective. The yttrium subgroup includes 66dysprosium, 67holmium, 68erbium, 69thulium, 70ytterbium, and 67lutetium. Rare-earth elements, especially those of the same subgroup, tend to occur together rather than in discrete minerals.

Jan 1, 1975

By Ronald S. Conti

Historically, underground mine rescue teams have received training only in the course of actual emergencies, or in simulated mine environments, usually on the surface, with placards to identify objects and hazards. Also, while U.S. Federal Regulations require all underground miners to walk escapeways and conduct fire drills every 90 days, this does not fully prepare them for the conditions that may be encountered in real escape situations, such as smoke filled entries. This paper describes technology and realistic training simulations that have been identified for the general workforce and mine emergency responders. Of all the technology evaluated by underground personnel, laser lights and lifelines were most beneficial in leading personnel to safety and out of the mine in smoke-filled passageways. These technological advancements can improve the state of readiness for rescue personnel and increase the chances of survival for personnel escaping from underground emergencies.

By Natalie Zeleznik, Brian Hawkins, David Bradley, Rachel Gooding, Patrick Wilson, Brian Somes, Kevin Wegman

"To perform a probabilistic risk assessment (PRA), a method of quantifying the risks associated withinfrequent high consequence events, consequence models that generate representative estimates of human health consequences for a wide variety of representative scenarios are commonly used. Criteria that suitable models must possess include: (1) input requirements necessary to generate large volumes ofprobabilistic simulations; (2) the capability to output injuries with the necessary details and resolution;(3) the ability to capture the variety of different scenarios inherent in an assessment; (4) acceptable cost and computational requirements; and (5) sufficient stakeholder buy-in for community acceptance."

Jan 1, 2017

By A. An. Mushketov, A. Al. Mushketov, N. A. Sopina

"INTRIDUCTION At present, more and more metallized raw materials with a metallization degree of not less than 80% are used in the smelting of steel. The main quantity of this raw material is produced in furnaces of mine type. Advantages of this type of raw materials for metallurgical processing are low levels of harmful and slag-forming impurities and a high content of metallic iron. At the same time, the cost of smelting raw materials and obtaining high-quality steels are reduced. In addition to the undoubted merits of metallized raw materials, there are high requirements for the quality of iron concentrates, which are the starting material for metallization: the mass fraction of acidic oxides should not exceed 3%; The mass fraction of iron should not be less than 69%, mass fractions of harmful impurities (phosphorus, arsenic, sulfur, copper, etc.) should not exceed 0.02%. These requirements are dictated by the fact that the recovery of burned pellets is carried out by gas in a solid phase. In this case, the empty rock and harmful impurities from the metal are not separated and sent to the steelmaking unit, increasing the heat consumption for heating and worsening the quality of the steel. The combined production of high-quality concentrate and metallized raw materials requires a large capital outlay from the enterprise, which in the future can be compensated for by increased profit from the sale of more expensive marketable products. At present, in the territory of Russia and the CIS countries Lebedinsky mining-and-processing integrated works is the only enterprise that carries out the entire chain of operations for the production of metallized raw materials, starting with the production of high-quality magnetite concentrate with a mass fraction of iron of 69.5% and ending with the production of a metallized product in the form of hot briquetted gland. JSC «SSGPO» is the largest iron-processing enterprise in Kazakhstan, which processes about 40 million tons of ore per year and receives 16 million tons of concentrate per year with a mass fraction of iron 66.0-66.5%. The technological scheme existing at the concentrator of JSC ""SSGPO"" includes the crushing of the feed ore to the size of 20-0 mm; dry magnetic separation operation; three reduction stages to a fineness of 90-95% kl-0.071 mm; operation of desliming, wet magnetic separation and filtration of the concentrate. Dry magnetic separation of the feed ore makes it possible to remove from the process of 19.6% of the tailings with a mass fraction of the total iron 12.5%, of magnetite 2.2%. The first reduction stage is carried out in rod mills with the volume of 40 m3 to a size of -1.6 + 0.0 mm. The first stage of wet magnetic separation is carried out in counterflow magnetic separators PBM-P-150/200L. The magnetic product of the first stage of WMS is classified in hydrocyclones; sands enter the second reduction stage into central discharge ball mill 3600 × 5000. Runoff of mills enter on the second enrichment stage in counterflow magnetic separators PBM-P-150/200L. The magnetic product enters the classification of the second stage, forming a closed cycle. Mass fraction of the class -0.071 + 0 mm in classifications runoff of the second stage is 70-75%. The second stage classifications runoff is transported toWMS-III operation in semi-counter separators PBM-PP-120/300. The magnetic product of the third stage enters the classification of the third stage. Granular residue are transported to the reduction of the third stage into central discharge ball mill 3600 × 5000. The mill runoff enters the third stage of classification, forming a closed cycle. Classifications runoff of the third stage enters on deslimation. Deslimed product is sent for fine screening to the crasher «Derrick» 2SG48-60W-5STK with a cell size of 0.1 mm. Top size of crasher is sent to regrinding. Undersize with a mass fraction of the class -0.071 + 0 mm 90-95% is fed to the wet magnetic separation of WMS-"

Jan 1, 2018

By D. J. McAdam

Results of investigation of corrosion-fatigue of metals at the U. S. Naval Engineering Experiment Station, Annapolis, Md., have been discussed by the writer in several recent paper~.1,2,3,4 In those papers references were also given to the work of Haigh in 1917.= Efforts by the writer to obtain a better understanding of some of the factors involved in corrosion-fatigue finally developed into a general investigation of the effect of time and cyclic stress on corrosion of metals. Corrosion-fatigue of Metals As described in the papers mentioned, rotating-cantilever specimens, conically tapered so that the stress is nearly uniform over a length of about 1.5 in., were subjected to simultaneous fatigue and corrosion. For this purpose a stream of water was diagonally applied so as to sweep the specimen from the outer to the inner fillet and surround the stressed surface with water. The fresh water is a calcium carbonate water, the composition of which has been given in a previous paper.2 The salt water is Severn River water having a saline content about one-third that of sea water. The previous papers described results obtained with ferrous and non-ferrous metals. The experiments showed that even slight corrosion simultaneous with fatigue may cause failure at nominal stresses far