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By M. Gensamer

IT has been suggested by a number of people that it would be worth while for some one to attempt to summarize or condense the proceedings of this symposium. This task has fallen to me as organizer and co-chairman. Its difficulty will be appreciated by anyone who attempts to read the whole proceedings. It is therefore with trepidation that I offer the following digest. In recent years there has been a renewal of interest in America on this subject of the cohesive strength of materials, and a growing appreciation of the need for a better theory of cohesion failure. The theories of elastic action and plastic action are well developed, particularly the former. The theory of plastic action is still in the course of development, but it is well along. Plastic action is terminated by cohesion failure and what is needed is a theory that will tell us when to expect the cohesion failure. In the past it has generally been assumed that cohesion failure will occur when a critical value of the maximum tensile stress has been reached. Many experiments have shown that this is not strictly true, and this symposium concerns itself with the failures of this simple hypothesis, and with the efforts that have been made to devise a more satisfactory theory. The most active contributor in recent years to knowledge in this field is Dr. McAdam, and he was asked to open the symposium with a summary or condensation of his papers and views. Undoubtedly it is presumptuous to attempt a still greater condensation, but perhaps it will be useful, because even his contribution to this symposium contains no summary, no concise statement of just what his contribution has bees. Dr. McAdam makes two main points. The first is that the cohesive strength is not a single valued quantity, but that it is a function of all three principal stresses and hence must be represented diagrammatically by a surface in a three-dimensional figure. Dr. McAdam has attempted so to delineate the cohesion limit, basing his

Jan 1, 1944

By Kung-Ping Wang

The mineral potential of the Far East, important to the United States for tin and tungsten as well as other minerals, is set forth in this first installment of a two part article by a specialist in the Far Eastern field. In this installment the mineral and resource picture of China, Japan, Korea, and Formosa are discussed. The second installment, in December, will cover Hong Kong, Indo-China, Thailand, Burma, Malaya, Indonesia, the Philippines, and British Borneo.

Jan 11, 1951

By F. J. Lecznar

An investigation of the problem of separating two minerals by a moving inclined plane has revealed that only minerals with considerable difference in sliding friction coefficients separate readily; that it is possible to separate two minerals when only one of them has a rolling friction coefficient; that difference in geometrical shape of the minerals is important to separation which improves as grain size increases; and that the thickness of the stream falling on the belt influences the grade of separation - the thinner the stream, the smaller the interference between the grains of the minerals to be separated and the higher the degree of separation. The problem of separating two minerals with different friction coefficients and shapes by a moving inclined plane has been investigated. Friction separators can be used to separate two materials that differ in shape and in friction coefficient. 1,3 Gladkov has presented some theoretical aspects of using a moving plane to clean corn and podded seeds; this method, however, did not result in practical application. When considering the separation of minerals, only those with considerable difference in sliding friction coefficients can be taken into account. Furthermore, it is possible to separate two minerals when only one of them has a rolling friction coefficient. The difference in geometrical shape of two minerals is also important to separation. It has been found that the separation of two minerals improves as the grain size increases. For example, coal and slate over 2 in. in grain size separate much better than materials of smaller grain size. As Table I indicates, the slate grains smaller than 25 mm gradually lose their flat shape with decreases in size and are more rounded than larger grains, which are almost flat. The smallest grains of slate in first and second fractions slide down the belt since their friction coefficients decrease and approach the value of the rolling coefficient. The percentage of separation of the first fraction is, therefore, low. Thickness of the coal stream falling on the belt also influences the grade of separation; the thinner the stream, the smaller the interference between the grains of the two minerals to be separated and the higher the degree of separation.

Jan 1, 1963

Sec. 1. The membership of the Institute shall comprise six classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6. Rocky Mountain Members. All shall be equally entitled to the privileges of membership, excepting that no member of any class whom residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the claw of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain members.

Jan 1, 1939

Sec. 1. The membership of the Institute shall comprise six classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6. Rocky Mountain Members. All shall be equally entitled to the privileges of membership, excepting that no member of any class whom residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the claw of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain members.

Jan 1, 1944

Cyril w. Knight, Toronto, Ont., Canada (communication to the Secretary*).—Mr. Hore's paper presents an interesting summary of our knowledge of this important mineral field ; and is therefore acceptable as giving information which our Transactions did not already contain, although it presents little or nothing not made known by other writers before 1906, when Mr. Hore began work in the field as a student assistant. Contributions of this kind, however, should be made completely valuable by such references to previous work as will enable the reader to follow to their original sources the theories or conelusions stated by the author. It is quite natural, and even excusable, that a new observer should find novelty in his on observations—especially if he is not acquainted with the work of predecessors in the same field. Moreover, the independent repetition of an observation or conclusion has a distinct value as a confirmation, though it may have none as a discovery. But the publication of it, without reference to its predecessors, may place the author in an unfavorable light as either ignorant of the history of his subject, or willing to claim credit to which he is not entitled. Of the latter fault, I do not accuse Mr. Hore ; but I cannot wholly acquit him of the former. Without disparaging his intelligent work, I must point out that his paper, as it stands, might easily give the impression that he claims originality for many statements which are by no means new, and that he emphasizes unduly his own publications. Thus, his remark (p. 481) "I have described the silver-fields in a general way in my paper " (not yet published), should have been accompanied with reference to some of the numerous papers, already published, which describe these fields. Again, on p. 486, he refers to four papers of his own on the Porcupine gold-area, but neither in the text nor in the appended

Jan 1, 1912

By Brij M. Moudgil

Disposal of fine coal refuse is one of the major technical problems which could adversely affect growth and development of the coal industry. At present one of the most: common methods for disposal of fine coal refuse slurry involves impounding the slurry behind dams. However meeting new federal and state government regulations for building, maintaining and reclaiming these impoundments in addition to terrain and space considerations render this technique to be only marginally competitive with other disposal methods. The coal industry has been actively engaged in developing alternate disposal techniques which are economically feasible and environmentally acceptable. A review of coal refuse disposal problem and current refuse disposal practice both in the eastern and western coal fields is presented. Various promising techniques being developed for economical and safe disposal of fine coal refuse slurry are also discussed.

Jan 1, 1980

INTRODUCTION It has been impossible for the student, the practicing engineer, and the geologist to find all of the essential elements of mineral appraisal and mineral economic analysis in a single text. Indeed, the most recent texts on mine evaluation are over 20 years old. Many of the basic principles of mine sampling and evaluation have not changed over the ensuing years, but with the advent of the digital computer the entire scope of mineral evaluation has been expanded to encompass superior techniques that heretofore were not possible when using manual methods. The old manual methods for ore reserve computations and the techniques for assignment of area of influence to drill-hole samples are now as antiquated as the Model-T Ford. With the computer making possible solutions that had not been practicable in terms of time and effort, it is important for the practicing explorationist and mining engineer to understand many of the new concepts and principles that can be applied with the resolving power of the computer. Many practicing mineral industry professionals have been disappointed by certain computer programs and thus have some reservations about computers being able to solve their very real problems. Often the gap between the practicing engineer and the ivory tower theoretician applying modern computer techniques is too broad to be bridged with scattered, fragmented publications. PURPOSE AND SCOPE OF TEXT It is the intent of this book to update and to unify a great many scattered reference works used in the mineral industry today. The ensuing pages are addressed both to the professional already working in the mineral industry who needs information on computerized methods as well as to the serious student seeking to grasp the fundamentals and modern techniques of mineral appraisal and feasibility. These techniques are based on sound mathematical principles and theory, with the computer as a tool-but a very essential tool-for the solution of the problems involved. The computer can be of value only if it is programmed by those having sufficient expertise to use its inherent problem-solving capability, and the output is interpreted by those who are sufficiently acquainted with its operation to understand the data it produces. In the pages that follow the author intends to outline in considerable detail all the essen-

Jan 1, 1980

By James Gayley

The paper presented to the Institute in 1910, by H. O. Hof-man, on Recent Progress in Blast Roasting,' has called the attention of the iron industry to the adaptability of these processes to the reclamation of by-products such as flue-dust and blue billy, and the better preparation of concentrates and fine ores for use in blast-furnaces. The waste of valuable iron-ore through the production of flue-dust has increased at an enormous rate, and much of it has in

Jan 1, 1912

By O. B. Hopkins

As prefatory to the body of this paper, a few general statements will be made (1) in regard to the history and importance of the asbestos, (2) as to the principal sources of the raw material, and (3) as to the types and modes of the occurrence of asbestos.

Jan 1, 1915

By C. R. Sundeen, C. W. Nicolson, J. D. McAuliffe, C. A. Campbell, P. D. Pearson

SHAFT SINKING SYMPOSIUM is a weighty term that could mean any number of things. However, in, this case it has been possible to utilize the transcription of the Annual Meeting Session of the same title and present it in much the same manner as the experts on the panel presented it to their audience Wednesday afternoon, February 18, 1953, at the Los Angeles Statler Hotel.

Jan 8, 1953

By Stanley B. Roboff

Throughout the world nuclear power re- actors are being designed and constructed as the energy source for stationary power plants. They are built to power submarines, surface ships, and long-range aircraft and to provide small package power plants that can be set up with relative ease in outlying areas. Regardless of type, most of these plants are designed to operate at the highest permissible temperatures and with the greatest possible burn-up of fuel. On paper it is now possible to design a nuclear power plant that will out-perform all existing types of power-generating plants, and at costs which are attractive. Such plants, however, are not now being built, nor will they ever be built, unless major engineering advances are made in the realm of reactor materials. The reason for this is straight- forward enough. Although it is known that huge quantities of energy can be generated in nuclear fuels within short periods of time, as yet there are no construction materials capable of withstanding the severe conditions that would exist within a power reactor operating with ultrahigh output.

Sep 1, 1956

By W. O. Philbrook, K. M. Goldman, G. Derge

EQUILIBRIUM conditions for steelmaking reactions have been studied extensively over the past two decades by a .number of investigators, with gratifying results. Equilibrium data are essential to the understanding of any process, and such knowledge has the practical utility of placing a limit beyond which control measures cannot succeed. When, however, the driving rate of an industrial process is so fast that there is not time for reactions to reach equilibrium, it then becomes necessary that the factors which control the rates of reaction be known in order to establish full control of the process. The desulphurization of molten pig iron by slags within the iron blast furnace is one such process in which the actual degree of sulphur absorption by the slag does not approach the equilibrium distribution obtained for similar slag-metal systems in the laboratory.' A study of the rate-controlling factors governing the desulphurization of iron by slags is becoming increasingly important as the sulphur content of raw materials increases with depletion of higher grade ores and coal. Following up an initial study on kinetics,' this paper reports some results of a continuing laboratory investigation on the mechanism of sulphur transfer between molten iron saturated with carbon and slags of the CaO-SiO,-A12O3 system. Laboratory experiments cannot reproduce in detail the conditions which prevail in the hearth of a blast furnace, but they will contribute to an understanding of the smelting reactions and perhaps will explain some apparent inconsistencies in the factors controlling the equilibrium distribution of sulphur between iron and slags under reducing compared with oxidizing conditions. The mechanism of a reaction—that is, the individual steps and the sequence in which they occur to produce the overall reaction which is ordinarily observed—must be elucidated to learn which steps are the slow ones, or "bottlenecks," that fix the pace of the process as a whole. In the desulphurization reaction, for example, the overall rate might, in principle, depend upon the rate of diffusion of sulphur in the metal or in the slag, upon the speed of some homogeneous reaction taking place entirely within one of the phases, or upon some heterogeneous reaction taking place across the slag-metal interface. Even some side reaction or the back reaction might have some influence. Evidence on all of these points will be presented in this paper. The rate of diffusion of sulphur in both iron and slag is so slow that it seems necessary to assume that convection provides the mechanism of carrying

Jan 1, 1951

Your outgoing President, following the worthy example of distinguished predecessors, submits a reckoning of his stewardship. He renders this fully realizing that without the hearty cooperation of Directors and Secretary, which he here recognizes most cordially, no President, who at best is but a passing force, can achieve markworthy results. The details as to your membership, finances, intellectual output, and,-other activities, have been submitted in the report of the Secretary.* It is enough to emphasize that during the year just expired, your organization has held two of its most successful meetings-one the largest in its history-has produced the largest number of papers, eliciting most interested discussions, has enjoyed its greatest income; and has received more than one thousand new members-passing the best previous record by more than one hundred, and exceeding the average increment of the, past five years by one third. It closes the year with 6528 members, the largest enrollment in its history. All of this might be true and yet the intellectual and social spirit, the loyalty of membership, the real life of the organization, might remain stagnant. As to these, it is for others than your speaker to testify. No comparison is feared.

Jan 3, 1918

By L. Adler

Analysis of a mine roof can be based on fixed-end beam behavior. The author here analyzes the effects of zero restraint at deflecting beam supports. Formulae are given for determining permissible support deflections. Analysis of a mine roof in a bedded deposit usually follows the assumption that the behavior of the roof is analogous to a beam with both ends fixed. Yet it is recognized that the end restraint itself varies with the thickness of cover, so that at shallow depth the restraint is minimum, and at great depth, maximum.' Consequently, an analysis on the basis of fixed ends or full restraint represents only one extreme in the possible range of conditions. Since the actual amount of restraint is difficult to ascertain, a more rational approach is to consider the two extreme cases of end restraint. Such situations regarding uncertainty of the restraining effects of supports are not uncommon in structural analysis, and are handled in a like manner.' Since previous studies9)4 have dealt with full restraint, this paper will analyze the effects of zero restraint at deflecting beam supports. In such a case a mine roof with several intermediate supports becomes analogous to a uniformly loaded continuous beam on simple supports, as shown in Fig. 1A. Such a structure is statically indeterminate to a degree equal to the number of intermediate supports, n. Therefore, with the three equilibrium equations, n additional equations are needed. A number of methods exist to analyze this problem, but The Theorem of Three Moments is Simplest. The continuous beam is divided at each support into a sequence of simply supported single span beams, with the unknown end moments, as appears in Fig. 1B. Continuity requires that the common ends of adjacent beams have the same slope (Fig. 1C). eiB= B(i+l)~= ei(i+l)and MiB= Mti+I)A= Mi(i+i). [1I A Glossary of all terms is given in Table I. Furthermore, if we first consider that the supports do not deflect, the slope at a support is the sum of the slopes due to each of the individual loads shown in Fig. 2, yielding:

Jan 1, 1961

By T. Sterry Hunt

IN my address on the " Geognostical Relations of the Metals," delivered before the Institute on the 20th of February last (Vol. I Transactions, p. 331), I spoke of the rocks in the vicinity of Thunder Bay, Lake Superior, where I indicated two series of uncrystalline rocks resting upon the Huronian schists, the lower one consisting of dark-colored argillites and sandstones overlaid, apparently in slight discordance, by nearly horizontal red and white sandstone and marls, which were compared with those of Sault Ste. Marie, and those of the Portage Lake district, on the south shore. These latter sand-stones, according to Brooks and Pumpelly, overlie unconformably the Keweenaw series of copper-bearing amygdaloids, sandstones, and conglomerates, and are in turn overlaid by the Trenton limestone. I then proposed to call this lower series of Thunder Bay, that is to say, the dark-colored argillites and sandstones which are traversed by the silver-bearing lodes of that region, the Animikie group. Shortly after the publication of that address I received an abstract of a paper on the geology of that region by Professor Robert Bell, read before the Montreal Natural History Society, February 24th. He there confirms the statement made in my address that the gold of Lake Shebandowan occurs in the Huronian, which is also seen to be cut by the silver-bearing lodes just mentioned. Professor Bell, in this paper, proposes to designate both what I have called the Animikie group, and the overlying red and white sandstones, by the name of the Nepigon group, for the reason that the upper series is best displayed about Lake Nepigon. This latter series is by Logan supposed to be overlaid by the copper-bearing amygdaloids with conglomerates and sandstones of the north shore (apparently identical with those of Keweenaw) ; and the whole together, including the Animikie group, constitute his Upper Copper-bearing group. These copper-bearing strata are by him supposed to be overlaid by the red and white sandstones of St. Mary, which are apparently the same with those sandstones which, according to Brooks and Pumpelly, overlie unconformably the similar cupriferous rocks of Portage Lake, and are, in their turn, overlaid by the Trenton limestone. Thus the sandstones which at Thunder Cape overlie the Animikie group are by Logan placed in the midst of the Upper Copper-bear-

Jan 1, 1874

These pages may be used as order sheets. Mark the number desired opposite title of pamphlet wanted, add your name and address, tear out the sheets and mail them to us. Single orders 25 c. Pamphlets 10 c. each in lots of three or more. Pamphlets 5 c. each in lots of fifty or more. These prices prevail for orders for pamphlets of the same or different titles, when cash accompanies order. The pamphlets listed on the following sheets are advance copies printed to facilitate discussion at the meetings of the Institute. They are offered for sale at the reduced prices given above as long, as the supply lasts. This list is published in the Bulletin in order that members may have the first opportunity to secure pamphlets, which sometimes are in such great demand that the supply is exhausted before the wants of members can be supplied. The following list includes only a fraction of the pamphlets-that have been published by the Institute. Any other paper published by. the Institute may be obtained for the price of $1, except those published in Volume XXXI, which are rare. The, Institute is still selling back volumes of Transactions at reduced prices, but some of these volumes are becoming rare. and members who desire to complete their sets of these very important books on mining and metallurgy are advised to send in their orders as soon as convenient. The attention of members is also called to the bibliographical index of the science of ore deposits contained in the Emmons Volume which is selling at $3 in paper and $4 in half morocco. The Posepny Volume is already exhausted and members who do not get in their orders for the Emmons Volume at the present reduced price may soon find themselves unable to obtain it on such favorable terms.

Jan 7, 1917

These pages may be used as order sheets. Mark the number desired opposite title of pamphlet wanted, add your name and address, tear out the sheets and mail them to us. Single orders 25 c. Pamphlets 10 c. each in lots of three or more. Pamphlets 5 c. each in lots of fifty or more. These prices prevail for orders for pamphlets of the same or different titles, when cash accompanies order. The pamphlets listed on the following sheets are advance copies printed to facilitate discussion at the meetings of the Institute. They are offered for sale at the reduced prices given above as long as-the supply lasts. This list is published in the Bulletin in order that members may have the first opportunity to secure pamphlets, which sometimes are in such great demand that the supply is exhausted before the wants of members can be supplied. The following list includes only a fraction of the pamphlets that have been published by the Institute. Any other paper published by the Institute may be obtained for the price of $1, except those published in Volume XXXI, which are rare. The Institute is still selling back volumes of Transactions at reduced prices, but some of these volumes are becoming rare and members who desire to complete their sets of these very important books on mining and metallurgy are advised to send in their orders as soon as convenient. (See Advertising page 15.) , The attention of members is also called to the bibliographical index of the science of ore, deposits contained in the Emmons Volume which is selling at $3 in paper and $4 in half morocco. The Posepny Volume is already exhausted and members who do not get in their orders for the Emmons Volume at the present reduced price may soon find themselves unable to obtain it on such favorable terms.

Jan 6, 1917

By John M. Logan, John Handin

Quasi-dynamic triaxial compression tests have been done for the first time at confining pressures to 7 kb. The intermediate strain-rate apparatus employs a gas loading cylinder which allows axial strain rates up to 102/sec on a sample 2 cm in diameter and 4 cm long. Samples can be deformed at confining pressures to 7 kb. Strain gages bonded to the loading piston and to the jacketed specimen allow internal measurements of load and sample strains respectively. Westerly granite has been deformed at confining pressures to 7 kb, room temperature, and axial strain rates of 10-2 to 1/sec. An increase of ultimate strength with confining pressure was found as expected. The ultimate strength was also found to vary directly with increasing strain rate; the rate of rise increases with confining pressure. Brittle deformation has dominated the sample behavior. Solenhofen limestone has been deformed at confining pressures to 3 kb, room temperature, and axial strain rates of 10- to 10/sec. The brittle-ductile transition was found to take place at about 1.5 kb confining pressure at a strain rate of 10/sec.

Jan 1, 1971

By P. L. Hofmann

The National Waste Terminal Storage (NWTS) Program was established in 1976. The objective of this program is to develop the technology and provide the facilities for the safe, environmentally acceptable isolation of civilian- and defense-related, high-level and transuranic nuclear wastes, including spent fuel elements, for which the federal government is responsible. The principal emphasis of this program is on disposal in mined geologic repositories. Technology development in support of the NWST program includes the formulation and management of a strong basic science and engineering program to generate an appropriate data base to aid in understanding of the key geological processes and major engineering structures involved. The current status, problems, and future plans of the technology program will be summarized.

Jan 1, 1984