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By Regina Maria Pinheiro

This work has for objectives to characterize a waste generated in the form of sludge during the treatment of the effluent of a paper making industry and to evaluate the effect of its incorporation in the amount of 10 wt.% on the properties and microstructure of a clayey body used for brick production. For the characterization of the waste the following techniques were used: X-ray diffraction, X-ray fluorescence, differential thermal analysis and termogravimetric analysis. Incorporated bricks were produced in industrial scale before firing at 750°C in a Modified Caieira type furnace. The physical and mechanical properties evaluated were water absorption and compression strength. The microstructure of the fired ceramic was evaluated by optical microscopy. The environmental evaluation was made by solution test and atmospheric emission by monitoring the release of SO2, NOx and particulate material. The results showed that, in agreement with the characteristics of the waste, its recycling into red ceramic can contribute to decrease the consumption of fuel during the firing stage. The properties of the fired ceramic attend the norms. With respect to the environmental aspect, the incorporation of the waste did not impact the environment.

Jan 1, 2009

By Holger Witthaus

There is more than a century of experience in multiple seam mining in Germany. In several mines up to 20 seams had been excavated within the last decades. Due to the nature of the deposit and the history of technical development the older panels cause a complex stress distribution for the lower seams and the current longwalls in descending order of mining. The depth of the longwalls reaches up to 4000 ft. This causes a maximum vertical stress that reaches between 30 and appr. 60 MPa. To handle these conditions several support systems are applied for roadway heading. A central knowledge management system for ground control is used for design and dimensioning of support within the DSK. This paper gives an overview to the nature of German multiple seam mining and the solutions in matters of panel layout and support design. It describes the full lifecycle for roadways in the seam starting with the geological and geotechnical evaluation, the basics of roadway deformation in great depth, the development of planning tools and standards for German coal mines, the range of alternative of support systems and roadheading techniques, as well as the reinforcement measures and the processing of support at the T-junction of the face entry. This paper uses exemplary descriptions that are consolidated in a specialized reference book ?Gebirgsbeherrschung von Flözstrecken? ? ?Ground Control in Roadways? which summarizes the standards of ground control based on the development of the past 25 years in German coal mines.

Jan 1, 2007

By Elliott A, Kingsnorth D. J

The development of a large high grade spodumene orebody, in excess of 30M tonnes containing at least 7M tonnes at 4.0% Li20, by Lithium Australia Ltd at Greenbushes, Western Australia is significantly increasing the world consumption of lithium minerals. The availability of two low cost sources of lithium, spodumene concentrates (7.5% Li20) and glass grade spodumene (4.8% Li20) has been welcomed by the ceramic and glass industries as it assists them to lower their raw material costs at a time when they are facing severe competition from alternative materials. While there is no shortage of lithium reserves in the world, there has been a shortage of high quality lithium minerals. The Lithium Australia development has filled this need. The favourable factors of high grade, low impurities, open cut mining and existing infrastructure make this an ideal low cost source for a long term downstream lithium industry. The Lithium Australia mine development has filled the need for a reliable long term supply of lithium minerals. The long term viability of this resource is ensured by the unique combination of the following key attributes of the development : High grade reserves of 7.OM tonnes of 4.0% Li20 within 130 metres of the surface, contained within a total proven reserve of 30M tonnes of 2.8 % Li20. Open pit mining with stripping ratio of less than 2.5:1 waste:ore. Low impurities levels, particularly in those elements, that have a detrimental effect on the colour of glass/ceramics i.e. iron, manganese, titanium and chromium. An existing mine infrastructure that includes an adequate water supply for all foreseeable processing requirements. A sophisticated spodumene concentrator utilizing statistical process control to produce a consistently high grade product with minimal impurities. A technically qualified stable workforce fully acquainted with spodumene processing techniques. Greenbushes high grade concentrates have found ready acceptance in the specialty ceramic and glass industries during the past four years. The consistency and high grade/low impurity level of the product has enabled its use in the production of television tubes, oven to table ware, glass fibres, specialty glasses and ceramic glazes.

Jan 1, 1989

By R. Hamar, G. Lamanthe

"To realize complex shaped pieces, like turbine blades, superalloys are cast with the lost-wax process. The end properties of these parts depend upon their microstructure as well as upon the occurence of casting defects such as micropores and hot tears. Such features are governed by the local solidification conditions which may be describe by the calculation of thermal transfers between alloy and mould. It needs the evaluation of numerous parameters which are fitted from experimental measurements in real castings. In further simulations, any parameter may be changed, in order to determine its influence. Such a single modification is quite impossible to realize in real castings, which shows that numerical modeling is a very good way to study casting processes.This modeling technique of casting is applied here to the real study of a typical low pressure turbine blade of a civil engine.IntroductionAircraft engine manufacturers use superalloys to produce turbine blades. They have to obtain a given microstructure and to avoid solidification defects to give good mechanical properties to theirs castings. For example, microporosity is induced by a large shrinkage that cannot be completely fed with the remaining liquid alloy .The optimization of casting processes needs a good Knowledge of the solidification process, that must be controlled at every place in the casting, and at every time of its freezing. Material and heat transfers that occur during the solidification, can be estimated from rather complex calculations. To model these physical phenomena, the evaluation of many parameters must be made. In this aim, some casting experiments are fitted with numerous thermal captors. The identification of experimental and computed thermograms let us estimate these parameters.A long-range scientific cooperation between SNECMA and INPG has enabled the realization of such studies on this topic. From all of them, this paper describes an experimental and computed investigation which has been led on a typical low pressure turbine blade of a civil engine."

Jan 1, 1986

By E. C. Westman

Anomalous geologic or stress-induced conditions can create a hazardous working environment for underground miners. Seismic attenuation tomography provides a valuable tool for understanding static and dynamic conditions induced by mining. As a longwall shearer cuts coal, it generates seismic energy. As this energy travels through the rock mass it is attenuated in a manner proportional to the degree of fracturing of the rock mass. By calculating this attenuation at specific locations underground, the degree of fracturing of the rock mass, and hence the relative stress state or material properties can be inferred. The goal of this work has been to create a tool which can be easily used by the mining industry to obtain information about the distribution of stress concentrations or material properties across a broad area in advance of mining.

Jan 1, 1996

By P K. Banerjee, S Kumar

Indian iron ores with less than 62 per cent Fe are currently unexploited, except for a few sectors which export them to foreign countries. It is anticipated that by 2012 the countryÆs domestic steel production is likely to rise to the tune of 60 million tonnes per annum. To meet this requirement, it is necessary to utilise not only the existing high-grade deposits but it is also necessary to look into exploiting the leftover iron ores of lower grades. Hence, reserves with Fe content 62 per cent and below (particularly the ores with In the present paper, an attempt has been made to beneficiate three different types of low-grade iron ores selected from three different parts (states) of the country. In the paper, alternative routes for beneficiation and effective utilisation have been tested using different techniques in the laboratory in an attempt to match their (Al2O3/SiO2) ratio after thorough characterisation and liberation studies. The paper also encompasses the geological formations, occurrences and distribution of Indian iron ores as well as highlighting the problems associated with the fines, possible metallurgical routes, and their market segregation from the perspective of end users.

Jan 1, 2007

By Compiled by Staff

"INTRODUCTIONThe U.S. Bureau of Mines (USBM) was established in the public interest to conclude inquiries and scientific and technologic investigations on mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increaseee efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the U.S. Bureau of Mines to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, USBM reports the findings of its research and investigations in its own series of publications and also in articles that: appear in scientific, technical, and trade journals; in "" proceedings of conventions and seminars; in' reference books; and in other non-USBM publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make this kind of list both necessary and valuable.This edition describes reports and articles published during calendar years 1992 and 1993. It supplements the 50-year list of Bureau publications from July 1, 1910, to January 1, 196O 2; and these 5- year lists of publications and articles: from January 1, 1965, to December 31, 1969 4, from January 1, 1970,to December 31, 19745 , from January 1, 1975, to December 31, 1979 6 , from January 1, 1980, to December 31, 1984 7 , and from January 1, 1985, to December 31, 1989 8."

Jan 1, 1994

By David E. Nicholas

Design of underground openings is becoming more critical as the mine deposits become lower in grade, initial investments increase, ore depth increases, additional safety regulations come into law, and increased ore recovery is required for conservation of minerals. Stability of these openings is dependent on the strength of the rock mass and the pre-mine stress field. The rock mass is composed of solid blocks of rock (rock sub- stance) and structural features (faults, joints, bedding, etc.). Methods of testing the rock mass strength are improving and be- coming more common, however it is difficult to justify the high cost of large scale testing for an initial mine design. An alternative to testing the rock mass is to measure the rock substance and the structural features separately, and then combine them to estimate the rock mass strength. The rock mass strength will vary depending on the orientation of the opening with respect to the structural features. The other factor affecting the stability of underground open- ings is the pre-mine stress field. Methods are available to measure "directly" the pre-mine stress in competent and relatively massive rock. These methods are costly to employ, therefore, they may not be justified in an initial study. The pre-mine stress field can be estimated based on the structural relationships formed from past tectonic events.

Jan 1, 1976

By E. H. Burroughs, M. J. Gavin

The references in the following compilation are selected chiefly from the literature of the years 1915-1920 , though a few of the more valuable standard works published before that period have necessarily been included . References to many articles have been omitted purposely , because the material covered by them is duplicated in publications included in the bibliography . It is manifestly impossible for the Bureau of Mines either to recommend or adversely criticize the statements of the various writers , particularly as to cost and profit estimates in articles referring to American shales , but it is hoped that the investigator will use caution in considering such statements , as it is well known that much of the literature on this subject has been published for promotion purposes and is therefore over- enthusiastic . Bearing this fact in mind , the reader should be able to judge for himself the reliability or usefulness of these articles .

Sep 1, 1921

By Frederic Souche, Andrew R. Klaetsch, Brian Hann, Nick Goodenow

This paper describes support of excavation (SOE) design and construction for three large diameter shafts excavated through glacial soil and controlled blasting in complex sedimentary rock formations. SOE in soil consists of unreinforced secant pile rings designed to resist lateral pressure in circumferential compression, eliminating costly steel core beam reinforcing. Controlled blasting at the shafts, adits, and tunnels in densely populated neighborhoods requires managing risks to the public, buildings, and utilities. Controlled blasting approaches limited adverse impacts to receptors nearby while achieving adequate production and fragmentation. A site-specific observational approach was used to adjust blasting parameters, limiting the impact on local stakeholders while maintaining daily progress and managing overbreak.

Jun 13, 2023

By Elaine R. Goetz

The eastern and southeastern regions of Ohio are part of Appalachian coal country, with a documented 1,300 miles of streams impacted by acid mine drainage. Since 1995, partnerships of local watershed groups, government agencies, private industries and universities have focused on the remediation of the affected waterways. The partnerships have spent $2.4 million annually in constructing and operating treatment systems such as wetlands, anoxic limestone drains, successive alkalinity production systems, steel slag leach beds, and lime dosers. These systems have been partially successful, and water quality has improved in the region, but no treatment has yet met the ultimate objectives of low cost, continual remediation. Our research group has investigated an alternative system for acid mine drainage treatment: electrolysis combined with pH adjustment to selectively precipitate recoverable, saleable metal products to offset the cost of treatment. We utilized a $0.2 million pilot facility constructed by the Wayne National Forest, in Nelsonville, Ohio, to process approximately 40 L/min of mine drainage from surrounding seeps. The pilot facility has multipurpose tanks that can be adapted to process acid mine drainage with different characteristics, such as high or low aluminum content or high or low carbonate concentrations. Sodium hydroxide was used for pH adjustment. Results indicate that saleable product can be generated with this treatment technology. In an initial, not optimized trial, one seep yielded 4.7 kg of dried 69 % iron oxide product from 10 hours of pilot facility operation, treating 23,000 L with electricity costs of $4.68. Dissolved iron concentrations in the water were reduced from 242 ± 18 mg/L to 2.8 ± 2.0 mg/L (99.0 % removal) while the initial acidity of 443 mg/L as CaCO3 was neutralized to an alkalinity of 160 mg/L as CaCO3. Iron oxide can be sold as pigment for an average of $1.47 per kg in the United States. Currently, approximately 80 % of all pigment used in the United States is imported, and there is incentive to purchase domestically recovered pigment. If the iron oxide from the pilot facility could be sold as pigment for $1.47 per kg, 43 % of the operating cost (raw materials, electricity and construction costs) of treatment could be offset by the sale of the product. Considering the cost offset, the electrolysis process shows potential as a sustainable low cost alternative for treating acid mine drainage.

Aug 1, 2013

By R. Darlington, S. Ji

"High pressure die casting is a promising process to make thin-wall components with high dimensional accuracy and excellent surface quality. However, the non-uniformity is one of the important features in castings. The inhomogeneity in tensile properties and microstructural characteristics were studied for the castings with different thicknesses made by high pressure die-cast Al-Mg-Si alloys. For the local mechanical properties in the die-castings, the casting skin provided the highest, whereas the casting centre provided the lowest yield strength, UTS and elongation. The yield strength, UTS and elongation were significantly decreased towards the casting centre. The microstructural inhomogeneity is characterised by the segregation of coarse fragmented dendrites, the reduction of solute concentrations of Mg and Si, and the increase of porosity level from the surface to the centre of castings. The growth velocities of eutectic a-Al phase estimated using the Jackson-Hunt model confirm that the growth variation is larger in the thin castings than that in thick castings.INTRODUCTION Inhomogeneity is an inherent characteristic in as-cast microstructures of a variety of alloys because of their non-uniform chemistry, microstructure, defects, topology and the resultant mechanical properties in the different ranges of localization (Campbell, 2003). Generally, three types of inhomogeneities characterise casting microstructures, which include (a) the casting defects of shrinkage and gas porosity, misruns, cold shuts, inclusions, hot tears and hot spots; (b) the non-uniform microstructure from the surface to the centre of castings; and (c) the non-uniform microstructure from the dendrites grown from primary solidification and the structure formed during the subsequent eutectic solidification in inter-dendritic regions. The chemical composition and the morphology between the primary dendrites and the inter-dendritic eutectics also differ in the as-cast microstructure. Obviously, the inhomogeneity is different in the castings obtained from different casting processes."

Jan 1, 2018

By J. R. Heberger, B. H. Ngo

The Safety Pays in Mining v2.0 web application, developed by the National Institute for Occupational Safety and Health (NIOSH) Mining Program, helps mines determine the potential costs associated with mining injuries. This web app categorizes injury cost by part of body injured, by the cause of the injury, or by the nature of the injury. When the user selects one of over 150 common types of mining injuries, the app provides information on the distribution of costs of workers’ compensation claims for that type of injury. Based on other user inputs, Safety Pays in Mining v2.0 will estimate the total costs of the selected injuries and the estimated impact of total injury costs on mining company profits and will provide some examples of services and personal protective equipment on which companies could spend the savings that result from the prevention of injuries. This paper reviews the Safety Pays in Mining version 2.0 web application by discussing the development and updates to the app, how it is used to show the true costs of mining injuries, and how mines can benefit from using this app.

Feb 1, 2024

By J. Weyer

"A lot of incorrect, dangerous and misleading statements about the effect of CO2 on the human body can still be found in the internet, the media and in books. It is a fact that already low concentrations can lead to critical reactions, higher concentrations cause a narcosis. The real effect is not a lack of oxygen but an inner suffocation. The breathing reflex is decreased and the transport of oxygen in the blood is reduced due to a low pH value of the blood. Furthermore a reduced oxygen content in the air can also lead to the failure of diesel engines. MOTIVE Different gases can appear in active mines as well in abandoned mines, adits and caves. The most dangerous gases are CO, NO/NO2, H2S, SO2, CH4 and CO2. Although the general danger arising from these gases is mostly known some aspects are underestimated. Furthermore misleading or wrong statements exist about the detection and the effect of gases on the human body. This is especially true for CO2. In the last years a couple of accidents happened with a great number of injured persons and unfortunately also some fatalities. As a result wrong information and comments about the effect of CO2 have been published in the media. A huge unexpected CO2 outburst in a potash mine showed again some additional problems and limits for rescue troops. ORIGIN OF CO2 AND MISLEADING STATEMENTS ABOUT THE EFFECT ON THE HUMAN BODYCarbon dioxide can appear as free gas in the earth crust. It is especially known in significant concentrations in some potash deposits, in hard coal mines and some caves. Furthermore it can be formed due to complete oxidation of carbon. It can appear in technical processes. It is also used for or in technical processes, as fire extinguishing agent, as cooling agent, it is contained (added) in sparkling water or other soft drinks and it is formed by fermentation processes. Up to today a lot of wrong information about the effect of CO2 on the human body is published or is still in the mind of many people and unfortunately even in the mind of members or leaders of rescue troops. On August 16th 2008 a faulty CO2 extinguishing installation in the city of Mönchengladbach/Germany caused the injury of 107 people and the evacuation of further 150 people /1/. People on the streets became unconsciousness and felt down. Fortunately all could be rescued due to the immediate rescue operation of local fire fighters. Furthermore the CO2 concentration on the ground was diminished by help of a helicopter. What could have happen with the engine will be discussed later. After 6 days a second similar accident took place /2/. In the news members of the rescue teams explained that CO2 leads to suffocation due to a lack of oxygen. This is wrong! Also cave explorers often say that a burning candle can detect a low oxygen and/or high Carbon dioxide content in the air. This is also wrong and deadly dangerous! Similar statements we find nowadays in the internet /3, 4 and many other/. In a forum “science and mathematics > chemistry” several people say that winegrowers go with a candle into the vine-cellar to detect CO2 /5/. Again: this can be deadly! Another dangerous statement is that CO2 in higher concentrations leads to headaches so people should leave such areas. A last example found in the literature is that at 3 % the breathing volume is doubled and at a concentration of 20 % one can felt some warmth on the skin. Both is not wrong but can lead to false conclusions. /6/"

Jan 1, 2015

By W. J. Fene, G. W. Grove

An important activity of the Safety Division of the Bureau of Mines , in its efforts to reduce accidents , is the safety inspection of mines . Inspections are made at the request of the operators and are not connected with the inspections by the various State departments of mines . The operating management is furnished with a confidential report of the results of the Bureau's inspections , with recommendations for elimination of the hazards found . These mine - safety inspections include a study of mining practices , conditions , and equipment and in some cases the sampling and analysis of mine air and coal dust . The Bureau of Mines has no regulatory powers , therefore the recommendations made in these reports are merely suggestions , and operators are not required to adopt them . Mine inspections are a check on safety standards , methods , and practices and are essential to any accident -prevention program . A foreman or superintendent may be sincere in his efforts to operate a mine safely and believe that he has done everything possible to attain this end . However , experience has shown that because of his familiarity with the mine and the consequent " nearness " of its various features many unsafe conditions may be , and in most cases are , overlooked ; an inspector , particularly an outsider who is trained to look for hazards , can point out the unsafe conditions overlooked by the foreman or superintendent . Some companies employ safety engineers who make regular inspections of their mines , report substandard conditions and hazards found , and make recommendations for correcting them . Unless these recommendations are carried out the inspections have little value . In making recommendations , due consideration should be given to the feasibility of carrying them out ; the management may and very often does consider a recommendation impracticable because of the

Mar 1, 1935

By John L. Mero

"The ocean has served humanity as a source of raw materials for thousands of years, but only on a minimal scale relative to its potential. Exploration programs have shown the ocean to contain a large number of mineral deposits of great extent and attractive grade. Recent research has indicated that a number of these deposits can be economically exploited with present-day technology and that the cost of winning many industrially important minerals from the oceanic deposits is potentially much less than that of winning similar minerals from land deposits. Although the finding of mineral deposits in the sea is a relatively simple matter at the present time, the exploitation of many of these deposits has lagged due to the lack of the availability of specific mining techniques for the individual deposits. Within the past two years, however, several developments have taken place in the design and testing of ocean mining systems in depths of water as great as 12,000 feet which indicate that the problem of mining in the ocean may soon be solved.Within the next decade, the ocean should prove to be a major source of many minerals for society and should come to dominate as a source of such metals as copper, nickel, cobalt, manganese, etc. Within a few years of the initiation of the mining of the deep-sea metalliferous nodules, land sources of such metals as nickel, cobalt, copper, manganese, etc. will be seriously affected and it is conceivable that the present structure of the world mining industry will undergo a substantial change in character."

Jan 1, 1972

This field guide is designed for use in planning pollution control and reclamation activities on small sand and gravel operations. Its purpose is to assist operators in selecting environmentally desirable pollution control and reclamation procedures based upon their particular mining situation. The guide includes information on interpreting physical and cultural factors that must be considered in planning and implementing a mining and reclamation program, achieving environmental protection objectives, and improving community/industry cooperation. Included as appendices are a summary of state laws and a list of additional readings on the subject.

Jan 1, 1981

By Changqing Su

A batch incubation experiment has been carried out to investigate the optimal condition for the microbial remediation of hexavalent chromium (Cr(VI)) in soils contaminated by chromate ore processing residue at Hunan Iron-Alloy Factory in China. The optimal condition was obtained by comparing the remediation efficiency of Cr (VI) by indigenous bacteria under different culture media, the quantity of nutrient sources, the pH and the temperature. The results indicated that glucose and yeast extract was the optimal component of culture medium and the quantities of the above components were 8 g L-1 and 13 g L-1, respectively. The optimal temperature and pH value were 30_ and 10.0, respectively. A bioreactor was operated under the optimal condition to evaluate the efficiency of Cr(VI) remediation in the contaminated soil. The result showed that water soluble Cr(VI) in soils was reduced from 320 mg kg-1 Cr(VI) of the initial concentration to below detection limit after 30 h in a bioreactor. Thus, there is a large potential to make bioremediation for the reduction of Cr(VI) to Cr(III) by the addition of optimal culture medium under aerobic condition.

Jan 1, 2010

By J. W. Bridge

Triaxial compression tests at various confining pressures and temperatures, as well as tangent modulus tests using ultrasonic waves, were conducted for wax-coated granular composite materials. The material used is a surface for Thoroughbred horse racing. The purpose of these tests is to examine how track shear strength and tangent modulus at a range of loads respond to changing temperatures. Previous work has shown that a wide range of operational temperatures are experienced which have been reproduced in the lab. Using differential scanning calorimetry, it is confirmed that these operational temperatures correspond to distinct thermal transition regions for the wax that is used to coat the sand in these surfaces. Preliminary results show that both shear strength and tangent modulus are sensitive to temperature changes with maximum strength and modulus correlating with major DSC wax transition regions.

Jan 1, 2010

By John T. Cumberlidge, Frederic M. Chace

Nickel-bearing saprolite developed during the early Tertiary over a northeast trending ultramafic body of Jurassic age near Riddle in southwestern Oregon. The principal nickel mineral is garnierite, but other complex nickel minerals may be present. There are two main ore bodies, an upper (older) one associated with the Klamath peneplain, and a lower (younger) one on the Sherwood peneplain. Saprolite constitutes the bulk of the ore and was probably derived from peridotite and dunite through chemical decomposition by downward percolating meteoric groundwater. Decomposition took place by net loss of MgO, SiO2, and Fe without a change in volume. Faults and joints provided permeable zones which localized saprolite development, and faulting may have helped preserve some ore from loss by erosion. Garnierite-chalcedony boxwork ore was deposited by meteoric groundwater along faults, joints, and at the level of former water tables. Boxwork ore is entirely supergene, the chemical constituents having been derived from higher in the soil profile. The saprolites show evidence of both supergene and residual enrichment in nickel. Red and yellow soil occurs as a capping over saprolite and boxwork, and was derived from them by chemical and mechanical decomposition. The present deposits are probably truncated remnants of a formerly thicker and much more extensive deposit which probably included laterite at the surface. The deposits started to form in the early Tertiary due to deep chemical weathering under sub-tropical to warmtemperature conditions. Early Tertiary ero~ion surfaces of low relief probably contributed to the predominance of chemical weathering over mechanical erosion. Alteration under present climatic conditions favors the formation of soil from saprolite rather than the formation of new saprolite from peridotite.

Jan 1, 1968