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By Santosh Kumar Ray, DEBASHISH MISHRA, Niroj Kumar Mohalik, SOMU MANDAL, Jai Krishna Pandey, Asfar Mobin Khan

Coal is a low-cost and high-calorific-value fuel. The coal mining industry worldwide has been suffering from severe accidents due to coal dust explosion hazards since its inception. Statistically, it was observed that 12,489 fatalities had occurred in 104 reported mining accidents from coal dust explosions during 1900–2020. There are numerous methods for detection, prevention, and control of coal dust explosions in mines. The underground mining environment is unpredictable and has an array of variables. These undulating factors make it difficult to prevent or control the coal dust explosion hazard. However, coal mining is done aggressively throughout the world, especially in developing countries as coal is a major source of thermal energy used in power plants contributing to about 38% (IEA, (2019), World Energy Outlook, IEA, Paris https:// www. iea. org/ repor ts/ world- energy- outlo ok- 2019.) of world electricity. Worldwide, coal dust explosibility studies are carried out in experimental mines, laboratories, and simulations. The complexity, lack of proper infrastructure, and unavailability of laboratory equipment sometimes make it difficult to study coal dust explosibility. The authors have discussed in detail and proposed that the CFD modelling can be a viable option for studying and evaluating coal dust explosibility.

Jun 29, 2022

By Carle R. Hayward

(Wilkes-Barre Meeting, June, 1911.) THE growing importance of metallography has caused a corresponding interest in the improvement of apparatus for preparing specimens of metals and alloys for microscopic examination. The purpose of this paper is to describe an electric heating-furnace, a grinding-and-polishing machine, and a device for mounting specimens, which are used in the metallographical work at the Massachusetts Institute of Technology. These three pieces of apparatus were designed and made in the laboratory of the Institute, and. each possesses some original features which may be of interest. ELECTRIC HEATING-FURNACE., The accurate control of heat necessary for metallographic work is best obtained by the electric-resistance furnace. Unfortunately, however, even the platinum-wound furnaces deteriorate with use and ultimately burn out, while the cheaper resistance-materials are often short-lived. Since the resistance-coil must be replaced from time to time, it is of advantage to be able to make this change with as little trouble as possible, and this is an important feature in the furnace shown in Fig. 1. A is a cylindrical galvanized-iron can, with two handles, B. A porcelain tube, C, passes through the central hole in the cover of the can and rests upon the asbestos disk, D; the bottom of the tube is held in place by the asbestos ring, E. The space, F, around the tube is filled with powdered magnesia. G is an ordinary assay-crucible, with the cover inverted so as to present a smooth top for supporting a second porcelain tube, H. The latter is wound with ?Excello " resistance-tape, 0.014

Dec 1, 1911

By J. G. Hadley

IN THE early stages of the depression the Utah Copper Co. realized that an unemployment problem would he created which demanded an intelligent and sympathetic solution. The company recognized that as many men as possible must be kept at work on a basis which would ultimately permit of the most efficient reabsorption of displaced labor. The company therefore determined to distribute available work among the greatest number of men and to that end adopted a system of rotating employees on a part-time basis. An employer requires a certain number of days' or shifts' work during the month. Obviously one employee working thirty days or shifts a month is equal to two employees each working fifteen. In principle, therefore, where two employees equally fitted to do certain work are available the work could be divided between them on an equitable basis and twice as many persons would benefit. A rotation plan on this basis was adopted by the Utah Copper, Co. on Jan. 30, 1930. Some variations of the orig¬inal plan have been made from time to time, the reasons for which will be discussed.

Jan 1, 1932

By Erik Westman, BEN WESTON, SETAREH GHAYCHI AFROUZ, KATHRYN DEHN

This study investigates the changes in seismic velocity of rockmass before and after three major seismic events to determine any potential identifiable precursory velocity changes associated with these events. Induced stress measurement is one of the challenging tasks in deep underground mining, with extreme impacts on the safety and stability of the mine. This study used p-wave passive seismic tomography to image the velocity redistribution within a rockmass, which can indicate induced stress level changes in the rockmass and detect the velocity changes that might precede a major seismic event or a rockburst. The ultimate goal of this research focus is to develop another tool for the deep-mining community that will help to increase safety and efficiency. For this purpose, the hypothesis of conventional mechanics, which implies induced stress at the hypocenter (as inferred by the p-wave velocity) increases until the seismic event occurs, is evaluated. It is found that the p-wave velocity did not increase at any of the three hypocenters prior to the seismic event occurring; however, the p-wave velocity did increase in the closest “zone center” for two of the three events. 

By P. K. N. Raghavan

Bauxite is the principal source for the production of aluminum metal which has gained tremendous importance over the years due to its versatility as a metal capable of substituting almost all of the non-ferrous metals, non metals like wood, plastics, fibre glass, etc. and even steel in many applications. 90% of the high purity alumina needed for the production of this wonder metal in the world comes from bauxite. Even though alternate methods have been developed to produce alumina from non bauxite sources, owing to the high capital and operating costs involved, Bayer process still retains the superiority among all the methods by virtue of its simplicity and favourable economics. Bauxite continues to be the perfect ore for alumina production and its remarkable utilization makes it the most important non-ferrous ore. Most of the Alumina Refineries in the world process different types of bauxite and that too from varied sources. The technology employed in the Alumina Refineries depends on the Bauxite processed, with an ultimate view to produce alumina of required quality in the most efficient manner. Bureau of Indian Standards (BIS) and Indian Bureau of Mines (IBM) had from time to time put forward bauxite specifications for metallurgical and other applications. However, these are found no fully based on alumina technology, present developments and availability of different types of bauxite in the country. The aim of this paper is to provide scheme of metallurgical grading of Indian Bauxite based on the background of alumina processing technologies and availability of various types of bauxite in the country. Efforts are made here to evaluate beneficiation techniques for central Indian Bauxite from the point of view of alumina production. Keywords: bauxite beneficiation, digestion, alumina, gibbsite, bohemite, diaspore

Sep 1, 2012

By H. R. Banks

IF you have ever travelled in the valley lying between the Selkirks and the Rockies in the East Koorenay district, you will have noted that the former mountains are rounded and massive, while the serrated peaks of the latter, fingering into the sky, bring an entirely different. picture. These two mountain ranges, with the comparatively level valley between, serve splendidly to introduce the subject for discussion. It is rather strange that, despite the fact that wear is undoubredly the greatest force with which human ingenuity bas to contend, it has come in for very little study from the stand point of pure science. Empiricism has been the sole ally in the fight for improvement! That we may have a clear understanding as to what we mean by wear, I would include in the term the breaking dawn of ail solid matter, from the natural wearing dawn of the mountains previously mentioned, to the hale in the mill pipe-line, which forces one to shut-down-usually at some un-earthly hour-to carry out a repair. It seems a far cry from mountains to mill launders or pipe-lines, but, magnified sufficiently, most of the materials with which we have to deal would show surfaces not unlike those we see around us. The progressive steps of wear, or ?erosion' as our geological friends would prefer to term it, are exemplified in the two ranges of mountains and the valley between. True, the wearing dawn by natural forces is a slow process. The aeons which have passed since first these mountains were formed seem endless. The natural forces pitted against them seem puny in the light of the interminable rime that has been needed to effect the changes. But here, as in the case of the materials with which we are dealing day by day, the combination of many forces ultimately brings about that condition which we describe as 'worn out'. In the case of the mountains, it is when they are finally levelled into plains, and in the case of equipment which we use, it is when that equipment will no longer serve its purpose.

Jan 1, 1943

By T. R. Marshall

SAMREC (The South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves) Clause 7 notes that ‘Documentation detailing Exploration Results, Mineral Resources and Mineral Reserves from which a Public Report is prepared must be prepared by, or under the direction of, and signed by a Competent Person.’ Similar statements with respect to Competent Valuators (CVs) and Qualified Reserves Evaluators (QREs) are contained in the SAMVAL (South African Code for the Reporting of Mineral Asset Valuations) and SAMOG (South African Code for the Reporting of Oil & Gas Resources) codes respectively. What does it mean to be a Competent Person (CP) in the context of compiling/signing-off on SAMCODE (South African Mineral Code) compliant documents? What do the registration and experience requirements mean? Who is ultimately responsible for the report and what does such responsibility prescribe?

Sep 1, 2021

Willet G. Miller, Toronto, Canada (communication to the Secretary): In his interesting paper Mr. Lindgren says: " As to ultimate results, it would seem as if we should be justified in concluding, with Prof. Suess, that the gold-supply of the world will gradually decrease if no further important improvements are made in the processes for the extraction of this metal; but regarding events so far distant no predictions may safely be made." It seems to the writer that no very important improvements require to be made in order at least to keep up the present production for many years to come. In many parts of the world there are large deposits of auriferous material which can be worked if present conditions are slightly changed. In the territory occupied by the Archean protaxis of the Province of

Jan 1, 1903

By K Komori

Naoshima Smelter and Refinery has treated shredder residue and incinerator fly ash in Japan since 2003. As a highlight, a new incinerating and melting furnace, as well as fly ash washing treatment plant were newly constructed for pre-treatment of shredder residue and fly ash respectively, and the pre-treated materials are ultimately treated in the existing Mitsubishi continuous copper smelting and converting process line. Since wastes such as shredder residue tend to vary in size and in shape, and contain some chlorine, the installation of a new pre-treatment line was required. The combination of the new pre-treatment line with the existing Mitsubishi Continuous Copper Process line has created a highly efficient and environmentally friendly system for recovering and recycling of valuable metals that previously used to be sent to a landfill. This paper reviews the approach that Naoshima took to establish its current recycling business strategy.

Jan 1, 2007

By R. Flattery, Z. Agioutantis

Coal and rock pillar design is critical not only for mineral extraction but also for the safety of the mine operators. Pillar strength can be estimated through numerous empirical formulas that are available in the literature, which are typically based on a statistical analysis of case study data. The limitation of most of these equations is that they only considered the width to height ratio and in situ rock or coal strength for pillars in horizontal seams. The adoption of such equations to estimate pillar strength in inclined seams may overestimate the pillar strength and ultimately lead to a poor pillar design. This paper will discuss different techniques that can be used to estimate pillar strength in inclined seams as well as present preliminary modeling results for stress redistribution around inclined pillars. Factors in the parametric analysis include pillar shapes, geometry, and seam inclination.

Mar 2, 2022

By M. Somppi, D. Weirmeir, Z. Yamak

"Milling operations commonly employ activated carbon to capture complexed gold from lixiviants in leaching processes. As the carbon moves through pipes, pumps, vessels, kilns and other processes in the gold leaching circuit, this consumable may experience losses by various mechanisms like attrition, breakage, and rupturing. Whenever possible, capturing the fine gold-bearing carbon portion of this stream could provide value to milling operations at low capital cost and manageable financial risk. Identifying, testing, and validating the successful payback of a low-tech flocculant system is described. However, the work more closely explores a Monte Carlo risk-based methodology for understanding the potential payback of this project at various confidence levels – an approach that many improvement projects can follow where some level of uncertainty exists.INTRODUCTION Gold milling operations commonly employ activated carbon to adsorb gold from solutions. Normal handling causes the carbon particles from this material to abrade, break, rupture to a size that becomes too small for further use in the process. Operations often concentrate on capturing the fine particles because gold is associated with the carbon and this metal content can be a valuable revenue stream for toll processing. However, the small particle sizes become difficult to separate from the process and can ultimately leave the facility in the waste stream. Hence, operations often place a great deal of care in capturing as much fine carbon as possible by a variety of methods including using screens, settling tanks, and chemical methods. Retrofitting a circuit to capture more carbon fines is common but can expose the operation to financial risk. Approaching this potential improvement by leveraging a Monte Carlo methodology can be effective in understanding the risk and the associated payback of a project at various confidence levels. This method provides a strong framework for capital go-no-go decisions and the structure to validate the potential project success before implementation."

Jan 1, 2019

Recent expansion programs have made the Yunkang underground coal mine the number one producer in Shenxi Province. The mine is the newest in the Datong Coal Administration, currently rated at around 3 Mt/a of coal. Located in the Wa Chushi mountain range about 23 km north of the city of Datong, the mine has undergone a series of expansion phases since startup in 1973. Initial design capacity was 1.5 Mt/a and ultimately, production will be brought to an estimated 7.0 Mt/a by 1985, according to mine superintendent Li Jia-zhi. How Coal Occurs The coal, Jurassic in age, occurs in three economically identifiable seams designated No. 2, 3, and 7. Seams are 100-250 m below the surface. Reserves from this economic zone were not quantified, but Superintendent Li indicated that there was enough mapped out to sustain the expanded production rate for over 20 years. Below the Jurassic coal is another possible economic zone, a Permocarboniferous coal lying 400-600 m below the surface. Little development drilling has been conducted to ascertain its potential. The Jurassic beds are relatively flat and coal quality is reportedly one of the best in China. Heat content of the coal runs around 33.5 MJ/kg and the ash content is less than 10%. In some areas, it is less than 7%. Coal preparation is simple and involves a washing and screening separation into four principal size fractions. Washed coal is stored in one of six storage silos, each with 4000-t capacity. Mining the No. 2 Seam Since startup, primary production has been derived from the No. 2 seam. The coal is relatively hard and is topped by a hard cement-like conglomerate. These factors, coupled with an average thickness between 4 to 6 m, precluded the use of conventional longwall techniques, according to mine engineers. The solution was development of a room-and-pillar tech-

Jan 3, 1980

By S N. Nyoni, K C. Corin, C T. O’Connor

Considering future water scenarios, as influenced by the increasing scarcity of water and the move towards sustainable process engineering etc, the closed water circuit becomes an important point of study in metallurgical operations, such as in milling and flotation. However, a deterrent in the use of recycled process water is often a lack of understanding of the effects of the accumulation of dissolved ions and other process chemicals. Recovery of the valuable minerals may be impacted by the concomitant complex mineral-pulp chemistry interactions. Literature indicates that these interactions are not necessarily antagonistic to process outcomes. Wet milling using steel media results in the dissolution of Fe from the media, the rate of which is dependent, inter alia, on the type of media and the chemical conditions of the aqueous environment in the mill. The pulp-phase interactions of dissolved ions with sulfide minerals may result in significant changes to the chemical conditions in the mill, which may subsequently impact negatively on the flotation recoveries. To understand the effect of these interactions in the context of the processing of sulfide minerals, this study seeks to consider the effect of three factors, viz mineral type – pyrite (Py) and galena (Gn) -, milling media of different compositions – forged steel (FS), 21 per cent high chrome and ceramic media -, and water chemistry, viz, deionised water (DI) and synthetic plant water (SPW). Ceramic media and galena are used for the respective control cases where the milling media and sulfide mineral contribute no Fe species. Using DI as a control case, a high ionic strength case is used to mimic the changes in water chemistry for a closed water circuit. Batch flotation tests are used as a diagnostic tool to determine the effects of these media-water-mineral interactions to investigate correlations between the chemical reactions occurring and chemical species present during the milling process and the ultimate flotation performance.

Aug 24, 2022

By John D. Ridge

Here are summarized 162 papers, published between 1933 and 1967, that deal with various aspects of ore genesis. Emphasis is placed on additions to, or modifications of, ore-formation theory, no matter what type of deposit is discussed. More space is given to papers on the formation of base-metal sulfides solely because more papers are written on this subject. The final conclusion is reached that a chemically and geologically sound theory for the genesis of ore deposits can be built around the concept of concentration of ore e’ements in a magmatically produced ore fluid and around such surface processes as may act to concentrate economically valuable materials from rocks of any origin exposed at the surface.

Jan 1, 1968

"The National Mining Hall of Fame and Museum (NMHFM) announced the 2017 National Mining Hall of Fame inductees. This year’s inductees, selected by the National Mining Hall of Fame’s Board of Governors, represent exploration and extraction of new frontiers, environmental stewardship, leadership in formulating U.S. mineral policy, education, and research and development, including the use of computers in planning, designing and managing mineral industry operations. The contributions of these individuals have undoubtedly had a significant and lasting impact on the mineral and mining industry. These individuals were selected for being visionary leaders, innovators, authors, pioneers in corporate social responsibility, and long-standing advocates for the U.S. mining industry.Dr. Thomas V. Falkie, Leonard Harris, Dr. Vincent E. McKelvey, and Gordon R. Parker will join 236 other mining industry luminaries when formally inducted into the National Mining Hall of Fame on Sept. 23, 2017. The 30th Annual Induction Banquet and Ceremony will be held at the Pinnacle Club, Grand Hyatt Hotel in Denver, CO.2017 National Mining Hall of Fame inductees:Dr. Thomas V. Falkie — In a career spanning six decades, Falkie’s accomplishments in industry, academia, government and professional societies demonstrate a pattern of integrity and sustained excellence. His gravitas and management style left highly favorable impressions in every position he held. He was the chairman and president of Berwind Natural Resources Corp.; President of SME; President of the American Institute of Mining, Metallurgy and Petroleum Engineers; Director of the U.S. Bureau of Mines and head of the Department of Mineral Engineering at the Pennsylvania State University. He played major leadership roles in the American Mining Congress, National Coal Association, Mining and Metallurgical Society of America, and the National Mining Association. He served on the board of directors of Foote Minerals and Cyprus-Amax and was very active in the National Academy of Engineering, the SME Foundation and the National Mining Hall of Fame and Museum.Leonard Harris — A highly regarded metallurgist and business executive, Leonard (Len) Harris may be most remembered for the heart he has for the people whose lives were touched by his career. For more than six decades, Harris has been a true pioneer in corporate social responsibility, leading companies to understand that doing the right thing for the local people is also the best path to business success. After an early career in Australia and Ghana, Harris moved to Peru in 1955 to join Cerro de Pasco Corp., owner of several mines with one of the most complex metallurgical operations in the world. Harris was quickly promoted through multiple positions and was ultimately named director of metallurgy."

Jan 8, 2017

By L. Galarza

"INTRODUCTION Beneficiation of ores and minerals in a concentrator plant requires a significant amount of water [1] for the grinding and particle separation processes; most of it ends up being recirculated for reuse, slurry pumps are used after crushing and grinding feeding the ore to a classifier to separate fine-grained material (less than 5 mm) from coarse-grained material requiring further grinding. The lower ore grades [2] in the past couple of decades have demanded an increase on power size and efficiency of process machines to maintain a competitive plant throughput; Hydro-cyclone feed pumps to control both under and over milling or grinding are not the exception; Fig. 1 shows a conventional drive train [3] comprising an (1) asynchronous motor (also known as squirrel cage induction motor = SCIM), a high speed coupling (2), a gear reducer (3) and a low speed coupling (4) attached to the shaft of the pump (5), to accommodate the motor rated speed (typically 1800 rpm) to the process requirements (in the range of 250 rpm to 350 rpm), requiring additional components related to the gearbox: instrumentation, maintenance, disposable lubricants and filters, spare parts, thus reduces the overall system efficiency ultimately reflected into CAPEX and OPEX.WHY VARIABLE SPEED DRIVES FOR CYCLONE FEED PUMPS Hydrocyclones or commonly referred as “cyclones” are one of the most important devices in the minerals industry [4]; almost universally used in close-circuit grinding because of their high capacity and relative efficiency, the evolution of Power Electronics made affordable the use of Medium Voltage - Variable Frequency Converters (VFC) for Cyclone Feed pumps in combination with induction motors larger than 500hp (373kW) to gain multiple benefits: - Soft start with minimum electrical utility disturbance = inrush current mitigation - Full Torque available at zero speed for overload startup with pulp solidification after long still stand periods, superior to any other reduced voltage starting method. - Optimum and constant pump speed (independent of the electrical network or load condition), compared to across the line SCIM operation - Flexible Motor Voltage and Speed regardless of the power distribution Voltage and Frequency - Improved Power Factor (close to unitary), over the entire operating speed range"

Jan 1, 2015

By J. W. Jamieson

"The future of the marine mining industry is tied to the resource potential of the seafloor. Everything from economic feasibility, policy decisions and environmental impact assessments to extraction techniques and mining tool design rely on an understanding of the size, composition, and distribution of the deposits. Development and regulatory decisions must ultimately be tied to not only the grade and tonnage estimates of individual deposits or groups of deposits, but also an understanding of the uncertainty of these estimates. Here, we will discuss how seafloor massive sulfide (SMS) deposit grades and tonnages are evaluated, and the sources of the uncertainties associated with these values.TONNAGE UNCERTAINTYFirst-order tonnage (size) estimates for SMS deposits are primarily determined from calculating the volumes of material that occurs as positive bathymetric features on the seafloor. The extent of sulfide mineralization on the seafloor can be determined either from visual surveys (camera-tow, remotely-operated vehicle (ROV), or human-occupied submersible surveys) or from volume calculations of bathymetric features identified from digital elevation models of the seafloor, or a combination of both methods. For bathymetric models to be used to identify deposits in the absence of visual groundtruthing, data resolution of 1 m or less is generally required to confidently identify a feature as being hydrothermal in origin (as opposed to a volcanic or tectonic feature), and therefore near-bottom multibeam data acquisition (e.g., using autonomous underwater vehicle (AUVs) or remotely operated vehicles (ROVs) is required (Fig. 1). Specific characteristics of bathymetric features, such as shape, slope angles and surface roughness can be used to identify features of hydrothermal origin (Fig. 1). However, so far, bathymetric features mapped at a resolution of ~1 m cannot be relied upon to unambiguously distinguish a sulfide mound, and the additional use of multiple AUVmounted sensors, such as magnetometers, which can be used to detect hydrothermal upflow zones, or self-potential sensors, which detect electrical fields related to the oxidation of sulfide minerals, can increase the confidence that a bathymetric feature is indeed a sulfide body, without the need for expensive and time-consuming visual surveys (c.f. Petersen et al., this volume)."

Jan 1, 2017

By Cynthia Belt

"Before energy can be saved in the materials industry, the process must be understood. At the same time, baby boomers are starting to retire. New people are entering the field without experience and training especially in methods to save energy. Various classroom courses, seminars, books, software, and websites are available for the professional to better understand the industry with the ultimate goal to reduce energy use. This paper is a review of what is currently available with some comments on potential needs.IntroductionEnergy use is high within the materials industry. For the United States, the primary metal industry uses 8% of all energy used in manufacturing (Figure 1 )1 or 1, 736 trillion BTUs per year. Sadly, while energy use is high, energy management is not universal within the industry. Counting both internal programs and external such as the utility supplier, equipment manufacturers, federal and state programs, only 66% of primary metals companies participate in an energy management activity1.For the materials field, process heating is the majority of the energy use in a plant2. Understanding and optimizing process heating is a critical need for materials energy professionals. Surprisingly, process heating is not necessarily the work addressed within an energy program. The U.S. 2006 Manufacturing Energy Consumption Survey (see Table 1) found more primary metal companies addressing lighting with 31 % participation versus 15% with process heating work even though energy used in lighting tends to be a minor (in the range ofl-3% ofa typical plant's energy use)."

Jan 1, 2013

By Shail J. Butani

In 1986, the Bureau of Mines conducted a probability sample survey, Mining Industry Population Survey, to measure such employee characteristics as occupation; principal equipment operated; work location at the mine; present job, present company, and total mining experience; job-related training during the last 2 yr; age; sex; race; and education. The population estimates are necessary to properly analyze the Mine Safety and Health Administration (MSHA) injury (includes illness and fatality data) statistics; that is, to compare and contrast injury rates for various subpopulations in order to identify those groups that are exhibiting higher than average injury rates. This report uses the survey's results to characterize the U.S. coal mining workforce from March through September 1986. A companion report, Information Circular (IC) 9193, "Characterization of the 1935 Metal and Nonmetal Mining Workforce:' provides similar information for the U.S metal and nonmetal mining industry.

Jan 1, 1988

Contributions made by mining have played a much more significant role in the development of civilization than is generally conceded by historians or recognized by ordinary citizens. In modern society, mined products pervade all industry and the lives of all civilized people. Early man relied largely on stone and ceramics, and eventually metals, to fashion tools and weapons. Civilization was advanced by discoveries such as abundant supplies of high-quality flint in northern France and southern England and firesetting to break rock. Middle Eastern cultures flourished not only because of agriculture and trade, but also because of mineral-rich deposits nearby. The earliest miners date back perhaps to 300,000 BC; their quest was for nonmetallic minerals (chert, flint, obsidian) suitable for utensils and eventually for weapons. Other rocks and minerals (ceramics, clay, salt, meteoric iron) attracted the miners for jewelry, cosmetics, construction materials, food seasoning, and coinage. At first, their excavations were confined to the surface, either pits or placers. But by about 40,000 BC, mine workings had been extended underground as short adits or shafts, and by 8000 BC as elaborate interconnected openings 300 ft (90 m) in depth. Metallurgical separation of metals from their ores and their subsequent fabrication evolved gradually over the centuries, copper being the first liberated (c. 7000 BC) followed by lead, silver, gold, and iron. Man enhanced both the sophistication of his

Jan 1, 2008