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By R. M. Santmyers

Caesium, rubidium, and lithium are sometimes described as the minor or rarer alkali metals. They generally occur together in nature, although, lithium is distributed more widely and is far more abundant than either of the other two. The chemical, and even the physical, properties of these three elements can best be considered In conjunction with the more familiar members of the alkali group, sodium and potassium. The five elements lithium, sodium, potassium, rubidium, and caesium show an interesting gradation properties from member to member with the increase in atomic weights. All are silvery white and soft enough to be cut with a knife. They tarnish rapidly in air and decompose water at ordinary temperatures. The lowest temperature at which the action of the several metals on water can be de¬tected is -98°C. for sodium, -105°C, for potassium, 108°C. for rubidium, and -116°C. for caesium. The chemical activity appears to increase steadily from

Jan 1, 1930

By Shosei Serata

The application of conventional rock mechanics methods to complex ground is very difficult. Yet. In most underground mining, the ground is complex. Therefore. conventional methods are not only difficult to apply but are also generally ineffective in improving underground operations. Similarly, conventional rock mechanics instrumentation has not significantly contributed to improvement of mining practice. Rock mechanics instrumentation in underground mining operations is often considered to be" merely an expensive nuisance. A new system of mine instrumentation is changing this traditional view. The new instrumentation method, called the SPDR method, was originally devised by Dr. Shosei Serata to meet the specific requirement of establishing the Stress Control Method of mining upon a solid quantitative foundation. This instrumentation method has contributed substantially to the widespread success of Stress Control mining under widely varying ground conditions in different types of underground mines (1.2.3.4). The instrumentation method provides an effective means for optimizing Stress Control mining patterns, simultaneously achieving reduction in production costs and substantial improvements in safety (5). The principles and methods of the new instrumentation method are described below, with field examples.

Jan 1, 1986

By R. E. Chaves

San Martin Mine is an open pit, gold heap leach operation located approximately 70 kilometers from the Honduran capital of Tegucigalpa. Mining operations commenced in 2000 and were completed late in 2007, while heap leaching operations continue. Reclamation was executed concurrently with operations to the extent practical. The area has distinct rainy and dry seasons and closure objectives include: prevention and mitigation of acid rock drainage, sediment and erosion control, and mitigation of visual impacts. Final closure is well underway at San Martin and this paper describes the closure processes conducted to date, problems encountered, and the subsequent lessons learned.

Jan 1, 2009

By David E. Pearson

"There are many tests that can be used to characterize and classify coals, and describe their quality. One of the easier tests, and most versatile in its application, is petrography. Rank and coal type are precisely defined by petrographic evaluation, and in this paper they are compared with other definitions of rank and coal type. Brief descriptions are given of the various rank tests, and of rheological and coking tests used to describe coking-coal quality in Canada. Similarly, tests used to evaluate thermal coal quality are discussed. Finally, the use of these tests as parameters to classify Canadian coals is examined with reference to four coal classifications.Introduction Among all coals there are two independent variables that are required to evaluate coal quality. These are, coal rank and coal type (or composition), and although coal petrography can be used to precisely define them, other methods are often used to provide values that are, in fact, functions of rank and coal type. For example, volatile matter yield is used as a proxy for rank, and free swelling index is used as a proxy for coal type in the International Classification of Hard Coals by type. Currently, there are a number of methods in use in Canada to define rank. The approach taken here, (obviously the author's bias), is that Romax, the mean maximum reflectance of vitrinite, is both a quick and an accurate measure of rank. It is logical to compare the other techniques employed in the measurement of rank to this favoured method. Coal type is, in theory at least, simply a quantitative measure of the various varieties of coal. In practice, the microscopic entities are assigned to a Reactive or Inert category, and at that point objectivity fades from petrography. Despite this somewhat subjective approach, petrographic composition of coals remains an independent variable of such.importance that its place in the evaluation of coal is essential. In this paper, a variety of me.thods that are used to assess rank and coal type are reviewed and compared; the influence of these variables over other parameters that are used to determine the quality of metallurgical and thermal coals is examined, and their usefulness in coal classifications is discussed."

Jan 1, 1985

By John M. Devine

Hydrogen sulphide associated with natural gas was noted as early as at Point Albino, Canada. The presence of this impurity was recognized also in other of the earlier oil and gas fields, although the occurrence was by no means common. However, in recent years, with the development of the producing zones of test Texas and the Texas Panhandle, the Production of "sour" crude has increased greatly and hydrogen sulphide has proved a generally troublesome factor--frequently a major problem--in the drilling and operation of many wells in those areas. The problems arising from the drilling and producing of oil or gas wells in hydrogen-sulphide areas, fall under two general divisions: safety problems and corrosion problems. Mention is made of a third division which is closely related to the other two, that of treating--or the development of processes for the removal of hydrogen iron the standpoint of safety and health hazards, hydrogen sulphide in the petroleum industry has been discussed in a number of publications. Likewise, the problem of hydrogen-sulphide corrosion of production equipment has been given considerable attention in the literature.

Jan 1, 1931

By J. J. Sammarco

Light emitting diodes (LEDs) are emerging as viable replacements for incandescent-based cap lamps used in mining. The photometric and energy characteristics of these light sources differ in important ways. The present paper describes the performance of LED and incandescent sources in cap lamps in terms of correlated color temperature, color rendering, light output, electric power, ambient temperature and airflow, and light source aging. Importantly, these characteristics can influence a miner?s ability to spot mining hazards thus impacting safety. Secondly, some of these characteristics interact with the operating life of the cap lamp?s battery power, such that differences between LED and incandescent sources can be magnified toward the end of a 10­hour battery discharge cycle. Empirically, we have determined that after 8 hours at an ambient temperature of 25 °C, the average light output of an incandescent cap lamp can decrease to about 69% of its initial value when powered by a lead-acid battery and it can decrease to about 65% of its initial value when powered by a nickel-hydride battery. An LED-based cap lamp using a constant current drive circuit can maintain about 96% of its initial value when powered by a nickel-hydride battery. Real-world tests addressing the effects of ambient temperature and airflow on the light output of an LED and incandescent cap lamp were conducted in the NIOSH Safety Research Coal Mine (SRCM). The LED cap lamp yielded a vertical average illuminance improvement of approximately 9.5% and the INC cap lamp yielded a vertical average illuminance degradation o f approximately 4%. The differences between LED and incandescent cap lamps were further quantified by the calculation of ?mesopic luminance? data that indicated for the same photopic luminance (i.e., as measured using a conventional light meter) the LED cap lamp could be up to 38 % more efficient than the incandescent cap lamp with a lead-acid battery at the end of the 10-hour driving cycle. Lastly, accelerated life tests were used to empirically determine light output depreciation as the incandescent light source age approached its useful life. There was about a 35% decrease in light output. This is quite considerable, especially given that the light output will decrease an additional 30% to 45% over the period of a 10-hour shift. The implications of the differences between LED and incandescent sources are discussed. This information is crucial in determining how visual performance could be affected for real-world conditions where batteries discharge during the work shift and as the light source ages. To date, only idealized conditions have been used for LED and incandescent cap lamp visual performance research.

Jan 1, 2008

By William A. Hustrulid

A technical and economic evaluation of the potential for improving mining productivity through the use of underreamers in blastholes, specifically in relation to Minnesota taconite, Arizona surface copper and in situ mining operations is presented. Included are (1) a review of the drilling and blasting practices presently being used, (2) a discussion of current underreamer technology. (3) the presentation of a general economic cost model for underreaming, (4) the application of the model to surface taconite, surface copper and in situ mining, and (5) a summary discussion including required performance specifications, potential overall benefits, and recommendations for further development.

Jan 1, 1977

By Fred Breu, Ronald E. Heuer

INTRODUCTION The Point Lepreau nuclear generating station was constructed in the late 1970's and early 1980's by the New Brunswick Electric Power Commission. Point Lepreau is a small peninsula on the north shore of the Bay of Fundy, about 55 km west of St. John, New Brunswick. Cooling water for the plant was to be obtained from and discharged into the Bay of Fundy by the system of shafts and tunnels illustrated in Fig. 1. The design engineer for the cooling water system was Albery, Pullerits, Dickson and Associates, Ltd., Toronto. Ferrera-Resco Ltd, Windsor, Ontario, was contractor for construction of the cooling water shaft and tunnel system, which was done between 1976 and 1979. The senior author was project manager for Ferrera-Resco, the junior author served as consultant to Ferrera-Resco on evaluation of certain geotechnical questions which arose during construction. SITE CONDITIONS Geology Except for limited overburden soils at the onshore shaft sites, the tunnels and shafts were constructed entirely in Triassic conglomerate, sandstone, and siltstone, with some shale interbeds. The bedding strike averaged about N6°E, The dip was to the west at about 30° along the Discharge Tunnel and 40° along the Intake Tunnel. Rock along the Intake Tunnel was mostly sandstone and siltstone and more thinly bedded, with RQ D generally in the range of 50 to 60%. Rock along the Discharge Tunnel tended to be coarser sandstone and conglomerate and more thickly bedded, with higher RQ D averaging about 80%. In addition to bedding joints, two other joint systems were identified

Jan 1, 1985

By L. F. Reinartz

FROM the earliest times when our prehistoric ancestors laboriously fashioned crude tools and weapons from meteoric iron until our day when we manufacture steel in 150-ton open-hearth furnaces, the production of iron and steel has played a dramatic and important role in the development of civilization. Progress in the science of refining iron ore into iron and steel was painfully slow for many centuries. The keen scimitars of Damascus, the broadswords of the English knights, the coats of mail of French knights, and the Iron Pillar of Delhi are well¬known examples of medieval metallurgical technique. Expense and the scarcity of raw materials originally limited the distribution of iron and steel products. It was not until the nineteenth century that a determined effort was made to adapt the use of steel to peaceful pursuits. The spectacular and rapid strides made in the manufacture of steel during the last hundred years were hastened by the invention during the decade 1860 to 1870 of two great steelmaking processes-the Bessemer and the open-hearth process.

Jan 1, 1936

By C. H. Bucknam

A review of phase analysis methods used to characterize refractory gold ores is presented. Updating of assay methods using database technology, on-line instrument interfacing and response surface modeling is highlighted. The use of assay results to classify ores for metallurgical purposes is demonstrated.

Jan 1, 1987

This paper presents a study about reopening of a quarry near to the geothermal region of Kntahya, Turkey. The production method was gallery blasting which resulted in very high ground vibrations. Therefore the quarry had been closed down by the local authorities about 12 years ago due to possible damages to the geothermal resources. In order to reopen the quarry, reserve estimation and production planning studies needs to be carried out as well as applying environmentally sensitive production method. The result of reserve estimation studies showed approximately 12.5 Mt reserve in the area. The market studies indicated that annual production of 600 000 tonnes could be sold. These results justify to reopen the quarry. In order to overcome environmental problems, bench blasting production method instead of gallery blasting has been planned. This method enables to design a drilling blasting pattern that will almost result in no ground vibrations.

Dec 6, 2010

By H. W. Russell, Paul D. MILLER

IT is known that austenitic chromium-nickel steels that have free carbide in the grain boundaries are subject to intergranular corrosion. It is difficult to detect such a susceptible condition in a fabricated article because present test methods require a sample section for examination and in most cases this is difficult to obtain. The question of the nature and prevention of intergranular corrosion in austenitic stainless steels have been ably discussed by Bain and co-workers1-3 and by other investigators.4-10 The present methods of study subject samples to corrosive conditions in such reagents as the Strauss solution, a. mixture of copper sulphate and sulphuric acid. Such tests usually require at least 72 hr. to run. Various methods of measuring the degree of sensitization have been employed, such as the measurement of electrical resistivity, magnetic measurements, measurement of the degree of cracking produced on bending over a mandrel, and microscopic studies. The detection of carbides at the grain boundaries by metallographic polishing and etching methods is tedious and requires a skilled operator. A recent report on such methods of carbide detection is given by the American Society for Testing Materials Subcommittee VI of Committee A-10 11 and by Arness.12 The present investigation was undertaken to develop a simple test procedure for detecting carbide precipitation or susceptibility to intergranular corrosion. The test is designed for use in the plant and for the testing of fabricated structures. Carbide precipitation, the factor leading to susceptibility to corrosion, is produced by heating the alloy in the temperature range 800° to 1600°F., as in welding, in improper annealing or in service where such temperatures are met. The connection between such precipitation and susceptibility to corrosion has been thoroughly discussed, as has been the use of stabilizing addition elements to prevent precipitation. EXPERIMENTAL METHOD A small area of the steel under test is subjected to an anodic treatment in a cell that can be clamped onto a sample or an actual structure. The cell and electrical circuit used are illustrated in Fig. I. The cell C is lead, joined to the steel plate D and insulated from it by a short piece of rubber tubing E. The cell is forced tightly against the steel plate by a spring or clamping device. The seal formed by the rubber against the steel plate is sufficient to retain the liquid bath inside the cell. The spot treated can be made any shape desired, depending on the shape of the rubber gasket. The cell illustrated polishes a circular spot about 3/8-in. diameter. The bath consists of 60 per cent (by weight) sulphuric acid to which is added 5 ml. per liter of Glycyrrhiza extract (U.S.P.). The cell requires about 2 to 2.5

Jan 1, 1941

By Richard Thomas Newcomb

The trend towards proportionately rising volumes of surface mining through- out the world and especially in the United States has led some observers to predict that the future of underground mining is quite limited. Certainly, the simple extrapolation of current trends1 gives evidence of a compelling sort for the hypothesis that technological progress is proceeding at a faster pace in surface than in underground mining. This paper attempts to examine the basis for these predictions by searching the historical record on differential rates of productivity as these are observed in iron ore and coal mining. In recent years economists have discussed "technology gaps" among industries or segments of the same industry, by which they mean that mechanisms for invention and its diffusion are faulty or retarded in such a way that feasible cost-cutting innovations are not applied or developed, even though technicians regard them as practical.2

Jan 1, 1968

By Breno Carvalho de Oliveira

Neste trabalho é apresentado uma ferramenta de otimização multiobjetivo para planejamento da manutenção de ativos ferroviários. A aplicação foi modelada com base no problema do Caixeiro Viajante Multiobjetivo, considerando como objetivos a minimização da postergação da manutenção dos equipamentos e do deslocamento da equipe de manutenção. Foi utilizada uma instância real de 17 cidades que são atendidas por uma única equipe de manutenção. A ferramenta de otimização consiste na combinação do algoritmo SPEA2 (Strength Pareto Evolutionary Algorithm), da methaheurística GRASP (Greedy Randomized Adaptive e Search Procedure) e de uma heurística de busca local em vizinhança, cada uma com seu papel específico dentro da otimização. O algoritmo foi capaz de mapear soluções melhores que a atualmente adotada pela empresa, proporcionando uma economia significativa no valor total a ser gasto em um ciclo de manutenção dos ativos ferroviários.

Oct 30, 2017

By Li Huimin

In this paper the step of determining the property index and the program of mixture ratio design of stabilizing agent in deep foundation construction are presented. According to the principle of computer simulation, the model and the method of computer simulation for optimum mix design are set up. Also, the precision of simulation results has been estimated and verified experimentally.

Jan 1, 1991

By AIME AIME

The following changes of address of members have been received at the Secretary's office during the period of Jan. 1 to Mar. 15, 1907. This list therefore supplements the annual list of members corrected to Jan. 1, 1907, and brings it up to the date of Mar. 15, 1907. The names of members who have accepted election during January and February, 1907 (new members), are printed in italics. The large number of changes of address since Jan. 1, 1907, shows the importance of publishing these changes as frequently as possible, and the Bi-Monthly Bulletin has been selected as the means to present this information to the members of the Institute. By a simple method of cutting out these names and addresses and pasting them directly over the corresponding names in the annual list of members, the record can be kept practically up to date, and the value of the list correspondingly increased. For this purpose the changes of address have been printed only on one side of the page. The names of new members, being in italics, are readily distinguished from the others, and can be pasted in approximate alphabetical order on the margins of the pages.

Mar 1, 1907

By J. A. Relf

The construction of refineries and gas conservation plants in the general Edmonton area in the early 1950's made available large quantities of by-product liquified petroleum gases (LPG). These gases, together with discovery of increasing reserves of natural gas in the Edmonton area, provided Canadian Chemical Company with two of the necessities for petrochemical production, namely, available and reasonably priced raw materials and fuel. This paper outlines the development of the $83 million Edmonton plant from its origin, together with a brief description of the processes and some of the interesting features involved. Several economic aspects of the petrochemical industry are high-lighted including its importance to the local community and the province. The paper reviews the relationship between the oil and gas industry and petrochemical manufacturing and indicates some of the factors that may affect the future growth of the petro-chemical industry in Wes tern Canada.

Jan 1, 1962

By E. Allen Wendt

It is both a great pleasure and something of a challenge for me to have this opportunity to address a gathering encompassing such a wealth of expertise in the minerals field, It is particularly challenging because I have been asked to turn your attention from the relatively glamorous subjects of gold and money to the more mundane questions of our International commodity policy and the place of buffer stocks in that policy. However, these questions may be of more immediate importance for our economic interests at home and Abroad. I can testify that the problems affecting international commodity markets and the possibility of international action To resolve those problems are matters of real concern to Washington as well as to your industries,

Jan 1, 1978

By Ben Sosewitz

The subject of rapid excavation tunneling is one that is extremely important to the people in the Metropolitan area of Chicago. My personal observation is that it is also extremely important to the urban communities around the U.S., to many local and state governments, and to the public officials who are deeply concerned about state affairs and taxes. The Metropolitan Chicago area is in fact, (as are 40 other major urban areas in the U.S.) confronted at the present time with a very serious combined sewer overflow, drainage and pollution problem which accounts for an estimated 40% of the pollutional load on its waterway system. In response to this the District has to date spent some seven millions of dollars in an attempt to find the most economical solution available for the elimination of this problem. This study included extensive investigations of the geological strata, the quantity and quality of storm runoff to be dealt with, and the various methods of storage and treatment available. It has considered solving the overflow problem by a concept involving a series of tunnels, rock tunnels, shafts and storage areas which will collect, retain and subsequently treat that portion of the combined sewer overflow which can be handled in the most cost-effective and economical way, consistent with following the federal and state standards - with which we at the present time agree in principle.

Jan 1, 1997

By José L. Carvalho

"Time-dependent swelling deformation of several shaley rock formations in Ontario is a wellknown phenomenon. In shales and mudstones with a higher salt concentration in the pore fluid than the ambient fluid, the outward gradient generates an osmotic pressure which acts as the driving force for swelling. The swelling phenomenon appears to be related to ion exchange between the rock porewater and the surrounding water.The swelling potential is expressed as the percent swelling strain that occurs per log cycle of time, in either the vertical (perpendicular to bedding) or horizontal (parallel to bedding) directions. In addition, the swelling potential is also noted to be stress dependent. In practice, therefore, the conditions required for swelling are (i) the accessibility to water, and (ii) an outward salt concentration gradient from pore fluid of the rock to the ambient fluid. The relief of in-situ rock stress during excavation serves an initiating mechanism (Lo and Micic, 2010).INTRODUCTIONTime-dependent swelling deformation of several shaley rock formations in Ontario is a well-known phenomenon. In shales and mudstones with a higher salt concentration in the pore fluid than the ambient fluid, the outward gradient generates an osmotic pressure which acts as the driving force for swelling. Swelling is also controlled by the inter-particle bonding; if the bond strength exceeds the osmotic pressure, swelling will not occur, and vice-versa. The bond strength can be reflected by the calcite content which forms cementation bond between rock particles."

Jan 1, 2015