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By C. O. Swanson

CALCULATING the average grade of a gold deposit is a problem that presents certain unique difficulties. Particularly troublesome is the fact that the average of the samples taken from a deposit is likely to be higher than the grade of the ore that is eventually mined, even when allowance is made for dilution and other factors resulting from the mining operations. It would seem that this situation is due to the presence in the deposits of structural peculiarities which have not been properly taken into account, since estimating the average grade of the broken ore produced from the deposits does not present the same difficulty. It is therefore evident that structural considerations are of prime importance in estimating the grade of a deposit. This fact is clearly realized and taken into account in cases where the boundaries of the orebodies and the variations within them are easily recognized. But in many gold deposits this condition is not satisfied, a circumstance which can be regarded as the main source of difficulty. Lacking definite information concerning the structure, we are apt to use certain procedures which are either empirical or based on general probabilities.

Jan 1, 1945

The evident need to improve the reliability of fluid power systems in underground coal mining equipment prompted the U.S. Bureau of Mines, and later the Department of Energy, to contract with the Fluid Power Research Center at Oklahoma State University for a research project to develop methods for achieving this end. Since the work of the contract was completed at about the time DOE was relinquishing its underground coal mining projects to BOM it was decided to issue the final report under 80M cover. The contract revealed that the major causes of poor reliability were: (1) poor overall system design, (2) poor component contamination toleranace, (3) poor system filtration, and 4) poor maintenance practices stemming from a lack of defined maintenance procedures and enforcement of same. This report demonstrates the variability of the reliabilities of components of similar performance description when subjected to standard tests. Improved design procedures are recommended and the information needed to specify and select components whose reliability is predictable and optimum without sacrifice in performance or significant increase in envelope size.

Jan 1, 1983

By AIME AIME

ANOTHER meeting of the Institute has passed into history and it fully sustained the reputation of the Institute as a live organization of the men, and nowadays the women, concerned with the mineral . ? industries and those working therein. The field meetings of, the 1nstitute are cine of its pleasantest and most valuable features. As Dr. Raymond used to say, ((It is good for a mining engineer once in a while to see a mine" and these meetings bring back to the mines those who, through progress into higher executive positions, have come to visit them infrequently, at the same time that they give opportunity for the .younger men to see regions and mines aside from those in which they are then working. This, and the formal and' informal interchange of information resulting,, is of the greatest professional value to all, while the meeting of old and making of new friends causes each meeting to be notable in turn. This year's meeting at Salt Lake City was one of the largest that has been held outside of. New York City; 470 members and guests registered while many more were present at the sessions without attending to this formality. '

Jan 1, 1925

By Forrest T. Moyer

The National Safety Competition was inaugurated in 1925 by the Bureau o1 Mines, U.S. Department of the Interior, in cooperation With the Explosives Engineer. In the first nationwide contest, 210 mines and quarries were enrolled. In 1962, the thirty-eighth anniversary of the competition, 910 mines and quarries were enrolled. These participating plants were worked a total of 133,292,989 man-hours. Of the enrolled plants, 415 achieved injury-free operations tar the year, the largest number of perfect safety records in the history of the contest. In 1961 and 1962, the National Safety Competition was conducted and sponsored by the Bureau of Mines. In January 1963, the American Mining Congress became a cosponsor and participated with the Bureau in the award activities related to the 1962 contest. The basic purpose of the competition is to stimulate employees to work safely and too give impetus to the building of better accident-prevention programs. A well-designed and efficient safety program helps a company economically by cutting costs, preventing damage to equipment and materials, and reducing nonproductive delays. An effective safety program benefits the employee more directly because his injuries cause personal suffering, lost time, and lower living standards for his family. Since both have much to gain, management and workers should cooperate closely to eliminate disabling work injuries. The greater contest participation and the larger number of perfect safety records indicate increasing safety consciousness on the part of management and employees.

Jan 1, 1964

By Forrest T. Moyer

The National Safety Competition was inaugurated in 1925 by the Bureau of Mines, U.S. Department of the Interior, in cooperation with the Explosives Engineer. In the first nationwide contest, 210 mines and quarries were enrolled. In 1962, the thirty-eighth anniversary of the competition, 910 mines and quarries were enrolled. These participating plants were worked a total of 133,292,989 man-hours. Of the enrolled plants, 415 achieved injury-free operations for the year, the largest number of perfect safety records in the history of the contest.

Jan 1, 1964

By C. W. Davis

This paper is the second of a series of progress reports on a study, of the hydrometallurgy of manganese which is being conducted in an endeavor to make possible utilization of the large deposits of low-grade domestic manganese ores that occur in several States. There are at least four processes in which a knowledge of the action of SO2 gas on manganese oxides at elevated temperatures may prove of value. One ,of these involves dissolution of manganese from ores. The Bureau of Mines has investigated the hydrometallurgy of manganese by a process in which SO2 gas, a waste product at many smelters, is passed into water to form a solvent for manganese. Although Several manganese minerals acre readily dissolved, rhodochrosite (MnCO3) was attacked but superficially.§. Recent experiments have shown that a roast at 650 to 900°C converts the manganese of rhodochrosite to a form that is quickly dissolved by a weak SO2 solution. Introduction of smelter gases containing as much as 5 per cent SO2 during such a roast would not add much to the cost of the operation and might result in the formation of considerable water-soluble manganese sulphate.

Jan 1, 1930

By C. W. Davis

This paper is the second of a series of progress reports on a study of the hydrometallurgy of manganese which is being, conducted in an endeavor to make possible utilization-of the large deposits of low-grade domestic manganese ores that occur in several States. There are at least four processes in which a knowledge of the action of S02 gas on manganese oxides at elevated temperatures may prove of value.

Jan 1, 1930

By R L. Brathwaite

The gold-scheelite-quartz lodes of the Wakamarina valley were the most productive of the mesothermal gold-bearing areas in the Marlborough Schist. Most of the production came from the Empire City and Golden Bar mines which worked the Golden Bar lode. Only 134 m of its 1800 m strike length are accessible, in the No.2 level of the Golden Bar Mine. A fault has downthrown the Golden Bar Mine section by = 47 m and displaced it left-laterally by 18 m. The lode is a typical ribbon-banded mesothermal vein, averaging c. 1.75 m wide, and enclosing narrow horses of schist country rock. It is composed of bands of milky æbuckÆ quartz with thin laminae of schist. Scheelite occurs in short strings of grains within quartz on the footwall side of the lode and also in small quartz-carbonate veinlets in the foot wall and hanging wall schist. The lode quartz contains only localised traces of pyrite and arsenopyrite. They are more abundant in the wall-rock schist.   The Golden Bar lode lies within a steeply dipping normal fault, which, on its footwall side, is adjacent to a 40 m-wide, shallow-dipping mylonite shear zone. Within 1 m of the lode, the shear foliation has been dragged down to nearly parallel the lode footwall. Wall rock alteration is manifested by a marked increase in K and Rb, which correlate with abundant illite/muscovite and K-feldspar within 2 m of the footwall of the lode. Amphibole, stilpnomelane, and pumpellyite show a progressive decrease towards the lode. As and Sb increase close to the lode, but are at background levels within the lode itself. Enhanced Cr (150-430 ppm) in the quartz, relative to the schists (~40 ppm), suggests that the source hydrothermal fluids passed through and leached mafic rocks, such as the metabasites from the hanging wall of the lode (~400 ppm Cr).

Jan 1, 1995

By Kunihiko Takahashi, Gjergj Dodbiba, Hisayoshi Umeda, Toyohisa Fujita

"An increasing number of mobile phones is increasing the number of the discarded mobile phones. Many efforts are thus being made to collect and recycle these devices. This paper is a short introduction of the recycling system of precious metals from the discarded mobile phone, currently available in Japan. Moreover, an attempt has been made to compare the energy recovery and the mechanical recycling of plastic wastes from the discarded mobile phone. The assessment has been carried out in the context of the life cycle assessment methodology (LCA). The environmental impact of each option was assessed by calculating the following impact indicators: depletion of abiotic resources (ADP), and global warming potential (GWP). 1. Introduction In 2003, the demand for mobile phones was increased since the camera was included in a mobile phone and the 3rd generation of mobile phones was introduced. In turn, the number of discarded mobile phone is rising sharply. Generally speaking, all the metallic parts of mobile phones can be recovered and recycled by using smelting and purification techniques. The recycled materials are then used to fabricate other new products."

Jan 1, 2008

By Ralph D. Parker

THE subject matter of this paper will be primarily restricted to the metallic mineral industry, which last year was responsible for almost 60 per •Cent of the total value of Canada's mineral production. It has been written that, in the broad sweep of eternal time, sixty years is as transient as a flicker of lightning in a summer night's sky. In the history of mankind and human endeavour, however, six decades can encompass momentous events and far-reaching •circumstances, all of which affect the lives of men and change the destiny of nations. This observation is con-firmed very positively by a study of our Canadian mining history, from either the broad viewpoint of human progress or the more specialized viewpoint of national economy. The past sixty years have witnessed vast changes in the economic importance of mining in this country's affairs, and also in the technology of the industry. Mining has emerged from the days of rule-of-thumb practice and is now taking on the stature of a highly diversified science.

Jan 1, 1962

By Pat C. Hautala, J. R. Hoskins

This is a new era for the minerals industry. Never before has there been more need for effective communication. So said Robert Anderson, chairman and chief executive officer of Hanna Mining Co. He was speaking to the American Mining Congress's Communication Workshop. The question is whether there is enough industry concern to meet the challenge. Anderson observed that increased workshop attendance, in continuing tough times, reflects the industry's concern for communication. But, why were students, faculty, engineers, supervisors, and managers not at the conference? Communication applies to every manager, Anderson said. But he was the only operating manager present. And only one company sent operating supervisors. The remaining conference participants were public relations personnel, generally with nonmining backgrounds. And the program dealt mostly with public relations issues. Role of Communication in the Minerals Industry. It is well known that the minerals industry faces economic, political, and social problems. Economic shifts and foreign competition have created an international minerals industry and an international marketplace. This, in turn, calls for worldwide communication. Other factors effecting communication are: • Governmental protectionism as well as regulatory reforms call for increased interaction with governing officials. • Changing social values have created environmental issues and anti-industry attitudes. This intensifies the need for improved public relations. • Traditional work values are shifting towards self-actualization and humanistic movements. The work force is better educated and more informed. Employees demand more satisfaction, equality, and job autonomy. • The mining industry's task of managing its human resources is complicated by layoffs, job uncertainties, and bleak outlooks concerning employee morale and motivation. Technology and Information for a New Era As noted, this is a new communications era, one propelled by technology and information. Technology has led to reduced demand for raw materials by developing substitutes. Copper demand, for example, will never fully recover. Copper cables are replaced by fiberoptics; copper transmission lines, with aluminum. Technology has shifted the US from traditional to high tech and service industries. The speed, frequency, and scope of information transmission have greatly increased. But the most significant characteristic of this information is not the pace of advancing technology. It is the dramatic increase in the importance and frequency of our personal transactions. Knowledge has replaced raw materials and capital as the strategic resource. Information has replaced energy as the transforming resource. And the game against nature has become an interpersonal game (D. Bell, Post-industrial society, Physics Today, '76). In Megatrends, John Naisbitt says that information will soon double every 20 months. So, professionals will become "information workers." And communication will be the life channel of the information age. Thomas Wolfe said you can't go home again. Hanna Anderson said we are, indeed, facing a new day. It will never again be "business as usual." We must move into the information age with the rest of society. We cannot trust that the world will continue to rely on our products. Nor can we place the responsibility and control for problems and solutions outside the minerals industry. Improved communication is not a panacea. But, Anderson said, it is critical to the minerals industry. What is Communication? The word communication is overused. It is applied to every aspect of our lives. Satirist Tom Lehrer got sick of hearing about the need to communicate. He said, "It seems to me that if someone is having all that trouble communicating, the very least he can do is shut up!" Obviously, we cannot follow that advice (though we might wish that some others would do so). Communication is always going on. It is inevitable. Yet we have many misconceptions about com-

Jan 1, 1985

By R. G. Zaripova, N. D. Ryan, H. J. McQueen

The austenitic and ferritic stainless steels do not undergo any phase transformation that induces very fine grains in the product through thermomechanical processing as practiced in most other steels. Considerable grain refinement can be achieved by intense multistage deformation descending through warm to cold working; notably multi-axial forging of bulk material can attain high strains with diminished risk of cracking. Hot working to improve ductility yields finer grain sizes as the T is reduced and strain rate E raised; increased strain has limited effect due to the steady state regime. Ferritic steels develop subgrains with size diminishing as E rises and T falls with the advantage of retained strain hardening; recrystallization delivers grains several times the cell size. In austenitic steels, dynamic recrystallization (DRX) provides finer grains at higher E and lower T with a lower limit due to intergranular cracking. The DRX grains contain a strengthening substructure that can easily be retained by quenching; if static recrystallization is allowed to occur the grain size rises markedly. Multistage rolling with diminishing T is able to provide grain refinement to the same degree as straining at the finishing T yet provides better ductility. grains on recrystallization. As a result of the strain induced transformation to martensite, small subzero deformations of austenitic or duplex steels produce very high dislocation densities that yield marked grain refinement when they revert upon reheating.

Jan 1, 2004

By FRABK HERVEY PETTINGELL

THE stock exchange and its functions is about as well understood by the average individual as the fourth dimension. What is a stock exchange? Divested of the rules and regulations by which it is governed, and the facilities it provides for the convenient handling of securities, it would be in its nude state nothing more or less than a meeting place for brokers. The stock exchange in America dates back to 1752, when a group of merchants of New York established a meeting place at the foot of Broad Street for the purpose of dealing in meal and slaves. The first definite orgarization, however, had its beginning in 1792 when 24 New York brokers signed an agreement not to buy or sell public stock for less than one quarter per cent. commission. From this small group has grown by gradual degrees, the greatest organized security market in the world, namely, the New York Stock Exchange. At the present time there are 27 stock exchanges in the United States and 5 in Canada. Based on the volume of business transacted, the Los Angeles Stock Exchange ranks 6th among them. This is attributable to the fact that strictly speaking Los Angeles has never been a stock exchange town, like some other large cities. Take for instance San Francisco, which supported one stock exchange from 1862 to .1882 and has since supported two. No city, by the way, should tolerate two stock exchanges at the same time. It is an economic folly and a senseless duplication that can be compared with rival telephone companies or competing street railway systems, paralleling each other's lines and always leads to trouble and confusion, and sooner or later one or the other falls by the wayside. While Los Angeles has had stock exchanges of one kind or another since 1896, none of them attracted much attention until 1899 when the present exchange was organized and it did not get well under way until along in 1906.

Jan 1, 1925

By K. L. Paciorek

The aim of this program was to develop a reliable and meaning-ful basis for assessing certain safety aspects, namely fire and, in particular, toxicity hazards of articles employed in underground coal mining operations. The present investigation was concentrated on the thermal oxidative degradation of representative hydraulic fluids. To achieve this goal all products formed on thermal oxidative degradation of the fluids studied were analyzed, identified I and the amount of each individual species present was determined quantitatively on a weight of product per weight of material basis. The weight/weight data thus obtained can then be factorized to reflect the relative toxicity of each individual species present, using for example the Threshold Limit Values adopted by the American Conference of Governmental and Industrial Hygienists, whereby an overall "toxicity index" can be arrived at which makes it possible to compare the different fluids and/or classes of fluids in a quantitative manner insofar as their toxicity is concerned.

Jan 1, 1976

By Shirley F. Colby

The past 40 years have seen the sand and gravel industry grow from small roadside pits and holes in farmers' back yards to giant corporations selling millions of tons of sand and gravel each year and owning plants representing huge capital investments in land and equipment. The days hen a man could "work out" his taxes by providing the materials for nearby roads are gone forever. In addition to the hundreds of privately owned and operated plants, Government agencies operate sand and gravel pits and plants to supply aggregates for the tremendous road-building and public-works programs in progress during the past few years. EXPANDING PRODUCTION In 1940 the send and gravel industry produced almost a quarter of a billion short tons valued at more than 110 million dollars. This compares with less than 2 million short tons worth 1 1/2 million dollars produced in 1902. The practice of screening sand and throwing away the gravel in the early days of the industry's growth has stopped, and in 1940 gravel constituted two-thirds of the total production. In 1906, the first year in which sand and gravel were reported separately gravel accounted for only one-

Jan 1, 1942

By W. D. Mcmillan

Kaolin, or china clay, is the term applied to a group of hydrous aluminum silicates. Because of its purity, light color, and refractory properties, kaolin is used extensively in the manufacture of high-grade ceramic wares and as a filler by the rubber and paper industries. Although there are numerous pottery and enamelware plants in Texas, and large rubber and paper industries; all of the kaolin used in these plants is from other States, There are two known occurrences of kaolin in Texas, namely, the Leakey deposit in Real County and the several deposits of the Medley district in southern Jeff Davis County. An investigation of the Mueller kaolin deposit in the Medley district was undertaken by the Bureau of Mines. Following an examination of this deposit by W. D. McMillan, engineer in charge of the Texas field office of the Bureau of Mines, a proposal was made to investigate the deposit by diamond core drilling.

Jan 1, 1949

This paper discusses the social and economic impact of mining, and in particular goldmining, on New Zealand. The range of topics covered and their complexity has confined us in this paper to highlighting the main points of concern û a detailed report is under preparation. A major problem in undertaking this study was the lack of hard data on important environmental, economic and social issues and if there is to be effective planning in the area of natural resource use this situation must be rectified. The following conclusions were drawn: Goldmining was very important in shaping New Zealand's early social and economic development, providing wealth, employment and impetus for social change.Foreign investment and technology has been an essential element in New ZealandÆs economic development.Mining is a small industry at present by this must not be allowed to obscure its potential to broaden New Zealand's economic base and provide foreign exchange.With modern methods, development of mineral resources and environmental protection are not incompatible but certain unique and irreplaceable areas must be preserved.There are problems in evaluating mining and other projects because different groups hold different values, and arguments often hinge on the valuation of costs and benefits rather than the technical aspects of the analysis.Mineral exploration is a high risk business and the potential returns must be sufficient to attract capital if New Zealand's mineral resources are to be developed.A resurgence of goldmining will clearly have obvious benefits for Waihi but the local community must plan carefully for their future. New Zealand will also gain valuable foreign exchange required for higher levels of economic activity.

Jan 1, 1981

After a snap-shot survey of water quality of streams draining various coal measures carried out in 2000 - 2001, West Coast Regional Council expanded its monitoring programme to better establish the condition of streams draining coal mining areas and to characterise the variability of water quality with respect to stream flow. Samples were collected for water quality indicators such as pH, sulphate, turbidity, conductivity, temperature and dissolved oxygen as well as macro-invertebrates, fish and assessments of stream habitat. Water quality sampling was carried out at 27 sites on 21 streams located from Page Stream near Seddonville in the north, to Seven Mile Creek near Dunollie in the South, and to Garvey Creek east of Reefton. There was relatively low variability of pH, conductivity and sulphate concentrations at most of the sites sampled. Conductivity and sulphate concentrations reduced with increasing flow and pH generally increased. Significant effects on macro-invertebrate and fish populations were identified at several of the sites where water quality sampling was undertaken. Of the water quality parameters tested, macro-invertebrates were mostly affected by pH. Although not sampled directly (conductivity was used as a surrogate) heavy metal concentration may explain some of the variation in macro-invertebrate communities. Three creeks affected by mine drainage were sampled for fish and no fish were present. Fish appear to be more sensitive to acid rock drainage that invertebrates. Using data from this survey and other studies conducted in the region, the total length of stream that is actually or highly likely to be adversely affected by acid rock drainage was estimated at 125 km. This figure is useful as a gauge as to the magnitude of the issue in this region and for setting of priorities for remediation. However, as it is only an estimate based on limited sampling sites, it should be used with caution.

Jan 1, 2003

By Herbert H. Einstein

Appendices A through M contain information that is the basis for many developments reported in the main text (Parts I through V); this information is, however, not needed in applying the research results. Specifically the appendices contain: A: Geology of Sampled Sites B: Comparison of Distribution Forms with Observed Trace Length Frequencies C: Joint Attitude Pole Diagrams D: Resistance and Deformability of Rock Discontinuities E: Resistance and Deformability of Joints - Details of Data Recording Procedure F: Documentation and Details for Simplified 2-Joint Wedge Analysis G: Generalization of the Stiffness Approach H: Inadequacy Due to Simplifying Assumptions in Wedge Analysis I: Rock Slope Reliability Analysis: State of the Art J: Resistance Derivations for Mechanical Model K: Supporting Derivations for Analysis Method DAYLITE L: Supporting Derivations for Simplified 2-Plane Reliability Analysis M: Plots of SLOPESIM Runs

Jan 1, 1979

By J. H. East, D. Harrington

"INTRODUCTION The tremendous expansion of industry during the war and the unprecedented demands for metals and minerals are reflected in the production and use of explosives during that period. The increased use of explosives brought added safety problems to industry because of the necessity of using men as blasters who were not entirely familiar with and some who were totally unfamiliar with the characteristics of some or all of the various explosives. A discussion of the characteristics of the ordinary types of explosives used in: industry should assist in giving a better understanding of the hazards attending their use. Explosives are compounded so they may be used with reasonable safety provided the user understands and follows the procedure recognized as standard safety practice. Short cuts and the failure to understand and use recognized safe practices, as well as the selection of explosives unstited for the work at hand, are all part of the safety problem,The extent to which explosives are used in the United States is shown by a study of the statistics compiled by the Bureau of Mines 4/ regarding them. Some of these statistics are shown below and serve as an indicator of the tremendous number of men engaged in the transportation, storage, and use of explosives. Theme men are exposed to the inherent hazards attending this occupation and they should be familiar with the recognized safe practices relative to explosives."

Sep 1, 1946