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By John D. Campbell

"IS YOUR MANAGEMENT CONTROLLOOP FUNCTIONINGMineral processors make use of hundreds of control circuits in their mills, process plants, smelters and refineries, to optimize throughput and recovery and minimize cost. This afternoon, I would like to discuss what is probably the weakest circuit in any mineral processing operation - the management control loop.In their recent book ""The Winning Streak"", Goldsmith and Clutter describe extensive research on unsuccessful companies. They conclude that ineffective control, which does not immediately identify the problems, is one of the main failings of unsuccessful companies.We will look at the three key components of control which, from the manager's point of view, ensure that the loop is complete. These three are:• measuring what's happening,• assessing its significance, Rnd• altering performance.If we compare management control to process control as shown in this first figure, ""We see that parameter sensing by the analyzer in a process circuit is analogous to performance monitoring by management in a responsibility centre. The analyzer senses temperature, pressure, flow, weight or some surrogate indicator such as colour to indicate ion concentration. For manage1nent, the performance to rnonitor is dependent upon the objectives of the responsibility centre, and the key factors which affect these objectives."

Jan 1, 1985

By M. Javier

Defining the concept of sustainability is an important step for industry and society. It is necessary in order to clarify what it means when debunking the many misinterpretations pervasive in different levels of anthropogenic activities. Essentially, the extractive industry has a harvest of differences. Mining involves the extraction of natural resources which are finite, exhaustible, non-renewable, unsustainable, and pay only once. It is remarkable that the definition of sustainability that we will shortly arrive at has totally different characteristics from the definition accepted throughout society. We categorize nature as having its own destiny which is controlled by its own rules and principles and its own society, and is part of nature; therefore, society depends on nature and not vice versa as the initial focus. To society there are no conditions to humanize nature but only respect nature?s rules. It was a challenge to find simplicity for this task not only for the definition but also for the explanation of this concept specifically, to answer the question, ?what is the true meaning of sustainability?? Finally, we are also able through this definition to provide fuel for wide discussions and stimulate critical thinking to improve such a concept. As a result, we present this definition as the tool for society today and for future generations.

Jan 1, 2012

By H. Aykul

The choice of which mining method to use at many large surface coal mines is often dicated by what machinery is available or what experience the mine management can offer. One of the most significant surface coal mines in Turkey is owned and operated by the Turkish National Coal Board, located to the west of the city of Kütahya. The Seyitömer Lignite Enterprise (SLE) extracts low quality coal, the majority of which is supplied to an adjacent power station. The coal seems at SLE contain bands of ash which under normal mining conditions are extracted with the coal. This increases the ash content of the run of mine coal and results in lower efficiency at the power station and financial penalties for SLE. In this paper, therefore, selection of the best possible equipment and production method was identified to achieve high selective mining at SLE. The research found that two different high selective mining methods were suitable for selective excavation of the B3 seam, which were hydraulic excavator and truck and surface miner and truck combinations. It was also found that high selective excavation could provide the desired coal quality at 52% lower costs when the whole process (excavation, transportation, processing, etc.) was considered. Keywords: coal mining, surface mining, selective mining.

Jan 1, 2007

By Juan Camus

To understand why some companies excel in creating value, Jim Collins (2001) and a group of postgraduate business students engaged in a comprehensive, five-year research project. They examined 1,435 U.S. companies for more than 40 years, seeking those that made significant improvements in their financial performance over time. The distinctive pattern sought was: ?Fifteen-year cumulative stock returns at or below the general stock market, punctuated by a transition point, then cumulative returns at least three times the market over the next 15 years. ?The search identified 11 outperforming companies, all in different industries, that were called the ?good to great? companies. To contrast these companies with similar peers within the same industry, the search also selected a group of comparison companies that failed to make the leap from good to great. Collins then set out to examine the transition point. What distinguishing features did the good-to-great companies have that their industry counterparts did not? At the heart of the findings about these outstanding companies is what Collins refers to as the ?hedgehog concept? ? how to find the one big thing that the company must focus on. According to Collins, those who built the good-to-great companies were, to one degree or another, hedgehogs. Those who led the comparison companies tended to be foxes, never gaining the clarifying advantage of a hedgehog concept, being instead scattered, diffused and inconsistent. This insight is complemented by Peter Drucker (2004), an influential management guru, who asserts that the first question an effective executive should ask is: ?what needs to be done?? Asking this question and taking it seriously, he asserts, is crucial for managerial success; and that the answer almost always has more than one urgent task, but the effective leader only concentrates on one task. In this last respect, Drucker emphasizes: ?If they [executives] are among the sizeable minority who work best with a change of pace in the working day, they pick two tasks. I have never encountered an executive who is effective while tackling more than two tasks at a time.?

Jan 1, 2011

By James Wonneberg, William Edgerton

"Today’s underground construction megaprojects are tremendous feats of engineering on a massive scale, excavating through ground conditions once thought impossible, using new and innovative contracting practices. But one important truth remains unchanged; projects are built by people. What separates winning projects from the rest? Great people, working in great organizations. In straight-talk fashion this paper sets forth fundamental differences between good project leaders and bad ones, on topics ranging from client relations, design management, and scheduling, to use of the whiteboard, and everything in between. Broadly applicable to all corners of project delivery, this paper will resonate with project leaders from around the world and help identify skills necessary to succeed in the management of underground facilities. A NOTE FROM THE AUTHORS This is a training document, and not really a “paper” per se. We have attempted to tackle some big and potentially complex topics using bite-sized paragraphs, each of which are intended to promote thoughtful introspection and dialog. So please feel free to skip around, or even set this document down while you reflect on your own personal experiences, tactics, and philosophies. We have found that providing examples of “what not to do” is oftentimes more instructive than simply listing “what to do”, hence the Good/Bad format of this document. Please note that “PM” refers loosely to anyone on the project management team not just the “Project Manager”. We also wish to preface this with the following cautionary statements: • The authors do not pretend to be the “Good PM” in all cases. In fact, we’re almost certainly the “Bad PM” for some. We aim to improve on those areas. • It has been said that “The only real training for leadership is leadership.” (Antony Jay) We all started somewhere, and nobody has 20 years of experience on day one. • Converting this text into some sort of prescriptive checklist would be a disservice to the evolution of project management. Our world – and our awareness of it – is constantly changing. We must always be open minded to new ideas and different perspectives on project delivery."

Jan 1, 2016

By Tom Barczak

Early in my career, while giving a presentation on shield design for longwall mining at one of the International Conferences on Ground Control in Mining, the late Jim Scott told me that I was finally getting it, because ?I was starting to think like a rock!? Although I didn?t realize it at the time, those few words changed my career forever. At the start of my career, I did a lot of laboratory testing, taking advantage of the unique capabilities of the Mine Roof Simulator to study the performance and design characteristics of longwall shields. I had a pretty good handle on what made shields work and what made them fail, but I was still struggling with how and why they develop their in-service loads and what they were actually controlling as opposed to being passive bystanders in a world beyond their control. It became clear to me that the simplistic models of dead weight loading could not explain the behavior I saw and measured underground. The problem did not go away when I started studying standing support systems. Again, I learned much about the strength, stiffness, and stability of these supports and helped the industry develop several new support products that attempted to provide more efficient support designs. But here, too, the simplistic models of dead weight loading did not seem to fit for me. That?s when I began to incorporate the ground reaction concept as a way of integrating the support response and the ground behavior into a cohesive design methodology. The concept has its limitations, no doubt, but I believe some form of it will be the future of not only designing supports but also, in the broader sense, enhancing the engineering aspects of ground control. The paper presented at the International Conference on Ground Control last year by Esterhuizen (2010) on pillar behavior is evidence of this. Think like a rock. Jim Scott was right. It takes two to dance. You can?t dance alone and you will never understand ground control by thinking like a support! ?Dumb as a box of rocks?? I don?t think so. The answer lies in the rocks!

Jan 1, 2011

By J. B. Evans

"THE OPPORTUNITY to participate in a CIM seminarconcerning the direction of mining engineer trainingis perhaps fortuitous as it comes at a time when theengineering schools which have invited inspection byCanadian Accreditation Board of the Canadian Councilof Professional Engineers are examining theirrespective curricula.Currently there exists considerable soul-searching in various engineering schools across Canada where questions such as the following are being posed.- Have we achieved the correct balance between subjects related to technical methodology and subjects devoted to conceptual planning and design?- Should we include ""applied humanities"" in our program? (Whatever ""applied humanities"" might mean!)- Should courses covering pollution control, ecology, economics, technical writing, professional conduct and ethics be offered as compulsory subjects, as electives, or not at all?- Is it a better scheme to have students complete an Arts or Science degree before entering engineering?- Do we place too much emphasis on pure mathematics and sciences with the result that insufficient time is available for instruction in the engineering applications of these subjects?- Should English expression and/ or literature be included in the engineering programs and, if so, should these subjects be presented by the English department or by English lecturers captive to the engineering school? - Is the present program directed primarily at research activities rather than preparing engineers for their future roles in industry? - Should we teach our own versions of mathematics and physics? - Do we have sufficient engineers on the faculty strength or are we overloaded with Ph.D.'s from the pure sciences? - How flexible should the program be, what should the compulsory vs elective course content be, and what freedom of choice, if any, should be given with respect to elective courses? - To what extent should students contribute to faculty decisions?- How far should we pursue computer science subjects and do we need to make our students proficient in computer programming? - How far should operations research and mathematical models be carried in the undergraduate program when the students have limited experience in the real engineering world? - Realizing that an engineer never completes his education, should the undergraduate program cover ""bare bones"" engineering and should instruction in particular disciplines be left to graduate schools and / or industry?"

Jan 1, 1972

By D. M. Thayer

In the last decade public awareness of the need for pollution abatement has increased greatly. The concern that had been previously shared by local and state conservation groups has spread to create a national concern for preservation of our non-polluted environmental assets and regeneration of those that have been wasted. Because other current matters such as inflation, civil rights,' tax reform and the Vietnam situation have been the object of most national concern, an extremely strong national pressure base has not been brought to bear on the pollution control crisis. Yes, the word is crisis, for in many areas pollution is of critical concern. One has only to look at Lake Erie, the skies about our major urban areas and many of our major rivers and streams to see this crisis These are not situations that can be corrected overnight. We are faced with two basic problems that should be attacked simultaneously: (1) Cleaning up the present sources of pollution and (2) preventing the generation of new pollution sources. What approach should be taken? As in any engineering problem, the limits must be well defined before a final solution is attempted. Pollution must be defined on a national basis. This means that basic Federal legislation and control is necessary. This should reduce any competitive advantage that can presently be gained by movement of operations from one state or geographical area to another on the basis of differences in local legislation .and enforcement. By giving real numbers as guidelines, selective enforcement can be avoided. As a starting point, for a definition of pollution let us use the following - "Any change in the environment occurring from other than natural causes." This definition may not be satisfactory to all but surely we must be somewhat dramatic in our statements to counteract the present prevailing philosophy. Our statement of this philosophy - "At what level of pollution can we afford to operate?" On the basis of our general definition we would like to state what we feel should be the philosophical statement - "How little can we change our physical environment as a result of operations?"

Jan 1, 1970

By S. Schade, G. Möllemann, C. Niestroj

"Mining environments, whether open-pit or underground, pose difficult conditions for any sensor system. However, the ever-increasing need for automation requires the application and use of sensor systems in order to gather relevant information required for process automation. Ultra-Wideband radio (UWB) is a robust technology well-suited for underground applications. These applications include positioning and communication. This paper introduces UWB and presents results from measurement campaigns in harsh environments. Using filtering and sensor fusion precise and robust positioning can be achieved even in confinements of underground mining environments. INTRODUCTION Indoor positioning systems (IPS) are gaining ever more importance. Especially in light of ongoing efforts to reach the goals of what was coined as Industry 4.0 by the German government, the development of IPS is inevitable. According to a recent report about the “Global Indoor Location Market Outlook 2019” a growth from $ 597 million in 2014 to $ 3961.8 million by 2019 is expected [1]. Hence, there is also an economic incentive to pursue this topic. The mining industry is profiting from this development as well, since IPS are the basis for the automation of especially mobile mining equipment. Ideally, indoor positioning systems offer to position the equipment continuously and, what’s more, even in real-time [2]. Different approaches are available for IPS. The difference of these systems lie in terms of accuracy, cost, precision, technology, scalability, robustness and security. [3] At the Institute of Advanced Mining Technologies (AMT) of RWTH Aachen University, research suggests that one of the more auspicious approaches for IPS in the mining sector is the employment of ultra-wideband (UWB) radio technology. Because of this, there has been ongoing research into the best way to introduce UWB technology for the application in underground environments. The research started with an indoor positioning application, which only consisted of the UWB system. In the course of this, different algorithms were developed to enhance the system’s performance for the use in the mining industry. This led to the idea of sensor fusion in which the information of the UWB system are combined with infrastructure-independent technologies like inertial navigation systems (INS) and image-based technologies."

Jan 1, 2017

By B.S. Butler

If geology is to continue to serve the mineral industry with increasing effectiveness as it has done in the past, there must be a steady output of better and better trained geologists and engineers with broader geological background. It may seem that the education and technical training of geologists belong entirely to the universities and colleges and has nothing to do with either Government surveys or the mining industry, outside of these activities furnishing a field for future work for the geological student. It will take but the most casual look, however, to see the large influence of Government surveys in education. Geological Maps Geological maps are essential tools in teaching geology, without which the instructor would be lost. Maps are produced by mining and oil companies, by university workers and by other individuals and institutions, but nearly all of the comprehensive maps, and most of the maps of small areas that are available, are directly or indirectly the work of public surveys. Such surveys in the past have been the only organizations with the continuity of effort and funds necessary to carry out projects that must combine the work of many individual geologists over long periods. Have we all the maps we need and of the quality we need? I believe that all who have used general maps, like the geological maps of the world, the maps of 'North America and the United States, maps of the several states and of smaller areas, appreciate fully the value of the maps as they are but realize also the value of greater accuracy, which can come only by more detailed work; and there are many areas of which we have no adequate maps. Other Helps I have chosen to emphasize maps as a help in preparing the young geologist to go out from the schools with some background of what has been accomplished and some outlook of what is yet to be done. Maps, however, are scarcely more essential to the teacher than many allied helps. What would the teacher of economic geology do if the work by Government surveys along that line were to be blotted out? We may

Jan 1, 1935

By B. S. Butler

If geology is to continue to serve the mineral industry with increasing effectiveness as it has done in the past, there must be a steady output of better and better trained geologists and engineers with broader geological background. It may seem that the education and technical training of geologists belong entirely to the universities and colleges and has nothing to do with either Government surveys or the mining industry, outside of these activities furnishing a field for future work for the geological student. It will take but the most casual look, however, to see the large influence of Government surveys in education. Geological Maps Geological maps are essential tools in teaching geology, without which the instructor would be lost. Maps are produced by mining and oil companies, by university workers and by other individuals and institutions, but nearly all of the comprehensive maps, and most of the maps of small areas that are available, are directly or indirectly the work of public surveys. Such surveys in the past have been the only organizations with the continuity of effort and funds necessary to carry out projects that must combine the work of many individual geologists over long periods. Have we all the maps we need and of the quality we need? I believe that all who have used general maps, like the geological maps of the world, the maps of 'North America and the United States, maps of the several states and of smaller areas, appreciate fully the value of the maps as they are but realize also the value of greater accuracy, which can come only by more detailed work; and there are many areas of which we have no adequate maps. Other Helps I have chosen to emphasize maps as a help in preparing the young geologist to go out from the schools with some background of what has been accomplished and some outlook of what is yet to be done. Maps, however, are scarcely more essential to the teacher than many allied helps. What would the teacher of economic geology do if the work by Government surveys along that line were to be blotted out? We may

Jan 1, 1935

By Peter Q. Nyce

Law is as old as civilization. In its early stages the so-called law of the jungle, "the survival of the fittest," was entirely operative. Man was quite largely a law unto himself and was likewise his own lawyer. As civilization developed and individuals segregated themselves into bands or communities, man-made laws became a reality, the individual sacrificing certain privileges for the benefit of the band or community in which he was privileged to live. Our present system of law is a continued development of that process. Very early in this development the exigencies of the occasion called into being classes of individuals who were given to study the laws then existing, and this group became known as lawyers. They advised what could or could not be done under existing laws. They were the aggressors in formulating new laws and principles under which the communities must live. Concurrently with the development of the law and the lawyer, the engineering profession was born. In our early civilization, each man was his own engineer; he built his own home, constructed his own bridge, and provided his own means of conveyance. As civilization became more complex, technical study was required to consummate projects and thus meet the requirements of an expanding community. The engineering profession assumed this burden. Both groups were human and thus susceptible to human mistakes and errors. It was Macaulay who said: "The world generally gives its admiration not to the man who does what nobody else ever attempts to do, but to the man who does best what multitudes do well." BiRth of Petroleum Industry In 1859, by the completion of the Drake well in Pennsylvania, the petroleum industry as we know it was born. Its rapid progress since that time has been both extraordinary and remarkable. The zeal of the individual operator to secure all possible oil in the shortest time, even to the extent of bringing into possession a part of the oil underlying a neighbor's property, developed unnecessary drilling, wasteful methods of recovery, great loss of gas, the early abandonment of property with much unrecovered oil thereunder. Such methods, plus

Jan 1, 1931

By Roswell Johnson

ALL strata not yielding oil or gas in commercial quantities or a corresponding amount of water may be called dry in a wide sense. In petroleum geology,, however, we may exclude all sands of too low or fin porosity to yield gaseous or fluid contents to the hole drilled in the sand before any original pressure that its contents may be under is disturbed. Most rocks are of this class and they are not reservoirs in our definition; their "dryness" is wholly a matter of course. What are the contents of the pores or what is the exact porosity of such rocks is of almost no concern to us, for economically they are "dry." What does interest us is the content of a rock having sufficient porosity and the pores of sufficient size to yield oil or gas in commercial quantities, if they were present under original pressure: Dryness of these reservoirs is a matter of supreme practical importance. Three views current as to such dryness seem, to me, to apply in a few cases only. It is the purpose of this paper to give reasons for this position and for believing that, in ordinary sedimentary rocks, there is only rarely a reservoir of competent porosity and undisturbed pressure that is dry in the sense of not yielding water, oil, or gas when first penetrated. 1. Gardner1 writes of some Kentucky sands, "There has never been present any salt water or other water in the sand." Absence of water cannot demonstrate this position. It is necessary to show that the rocks were not laid down in water, but in air, and that they became so enclosed, while still above the water-table of the, ground water, that water has not been able to enter since. Most of these sands, and certainly the productive limestones, were deposited in water; and such sands as have been commercially productive show no reason for believing that the overlying shale or limestone was not laid down progressively from one direction and in water that would have flooded it. No adequate explanation has been offered for this hypothesis, which is so inherently improbable.

Jan 1, 1920

C. W. GOODALE, * Butte, Mont.-In regard to the employment manager, the North Butte Mining Co. has undertaken that line of work and the rest of the companies are watching the experiment. If it is proved to be the proper thing, the system will be introduced into other mines. We have to combat the opposition to the use of the "rustling card. It is nothing more nor less than asking the nationality, where the plan formerly worked, and whether he is married or single. ROBERT RHEA GOODRICH, Anaconda, Mont. (written discussion?).¬Since the efficiency of the different phases of personnel work employed by industrial concerns, which are bringing about greater efficiency and lessening the labor turnover, the latter being intimately connected with "contentment of mind," depends on the individual workman, it is highly desirable, as far as industry is concerned, to keep the workman's mind and body in trim in order to lessen accidents and produce a higher grade of work. Prevention being better than cure, health supervision of the workmen during employment should be maintained by the employers in order that mental alertness and physical well-being may be obtained. I have long believed, from observation in many plants, that when any problem is dependent on the individual workman, what he believes and what he does is vitally dependent on his health. I will follow with much interest what is to be clone in the future in relation to the subject of health supervision during employment (as well as medical examinations at the time of employment), and I hope this idea will be generally instituted in personnel work. A workman with good health and a contented mind should be an ideal component of a progressive industrial concern. The contentment of the workman is fostered by a number of admirable phases of welfare work which are being still further developed. The mental and physical well-being of labor should be the issue in Labor vs. Capital in the new period of the industrial promotion of the United States into which we are now entering.

Jan 4, 1919

By George H. Ashley

Mining, including quarrying, dates back almost to the dawn of history, beginning almost with the beginning of what we call civilization. State surveys date back about 100 years. Evidently mining flourished for thousands of years before state surveys were thought of. Why should it not continue to flourish without state surveys? First, it may be noted that as mining and civilization were contemporaneous, so state surveys and the science of geology were almost contemporaneous. As recently as 30 years ago the United States mineral laws were interpreted to mean that coal lands in the public domain were only those lands on which workable coal outcropped. The half billion acres of public land underlain by .coal but on which it did not outcrop were treated as homestead lands and open to settlement. Just what did the science of geology do to or for the mining industry? Until geology arose rocks or minerals or ores were where they were found. Their finding might be accidental, or might be the result of deliberate search or prospecting. In open, rocky country, with little or no vegetation, as in parts of the West, prospecting served very well, though at an enormous expenditure of human time and effort, if not money. The old saying that every dollar's worth of gold taken from the earth has cost two dollars may largely be charged to the time value of the usual method of prospecting. Geology changed all that. The science is still young and it still labors under handicaps of immaturity and early errors. Geology, however, has gradually been discovering the relations and conditions under which the several mineral deposits occur. Its elaborate studies of exhausted or nearly exhausted mineral deposits has done for it what human autopsy has done for medicine and surgery. Perhaps in no field is this plainer than in the oil and gas industry. Note might also be made of several important coal fields in England and on the Continent, in which the coal is everywhere deeply buried. Passing over the long period of growth during the past 100 years, geology today is prepared to offer the mining industry: first, a knowledge of the geologic conditions under which most minerals occur and to explore

Jan 1, 1935

By George H. Ashley

Mining, including quarrying, dates back almost to the dawn of history, beginning almost with the beginning of what we call civilization. State surveys date back about 100 years. Evidently mining flourished for thousands of years before state surveys were thought of. Why should it not continue to flourish without state surveys? First, it may be noted that as mining and civilization were contemporaneous, so state surveys and the science of geology were almost contemporaneous. As recently as 30 years ago the United States mineral laws were interpreted to mean that coal lands in the public domain were only those lands on which workable coal outcropped. The half billion acres of public land underlain by .coal but on which it did not outcrop were treated as homestead lands and open to settlement. Just what did the science of geology do to or for the mining industry? Until geology arose rocks or minerals or ores were where they were found. Their finding might be accidental, or might be the result of deliberate search or prospecting. In open, rocky country, with little or no vegetation, as in parts of the West, prospecting served very well, though at an enormous expenditure of human time and effort, if not money. The old saying that every dollar's worth of gold taken from the earth has cost two dollars may largely be charged to the time value of the usual method of prospecting. Geology changed all that. The science is still young and it still labors under handicaps of immaturity and early errors. Geology, however, has gradually been discovering the relations and conditions under which the several mineral deposits occur. Its elaborate studies of exhausted or nearly exhausted mineral deposits has done for it what human autopsy has done for medicine and surgery. Perhaps in no field is this plainer than in the oil and gas industry. Note might also be made of several important coal fields in England and on the Continent, in which the coal is everywhere deeply buried. Passing over the long period of growth during the past 100 years, geology today is prepared to offer the mining industry: first, a knowledge of the geologic conditions under which most minerals occur and to explore

Jan 1, 1935

By Allen Rogers

IT has always seemed to me that there is a certain similarity between the work of the mining engineer and that of the doctor of medicine-each has very often to be governed in his actions by conditions which he cannot. see. It is not necessary to detail the unseen conditions with which the mining engineer or geologist has to deal-the further extension of orebodies; the existence of new ones, the throw of a fault, the probable change in grade or character of the ore with advance of the workings, are a few of the conditions which the mining engineer has to determine as well as he can from the deductions he is able to make from what he can observe. Just so the physician is often confronted with conditions that he can not observe. Probably less than half of human ills make a manifestation at the surface of the body from which definite and certain conclusions can be drawn. The diagnostician must observe various things and, from these observations in combination, conclude what 'his course should be to bring about the cure of the trouble. Both professions would be assisted immensely by any agency that would permit them to look below the surface, something that would make more certain the diagnosis which each is called upon to make. The physician has had such an agency since 1895, when Röntgen discovered the X-ray; which, by making possible shadowgraphs of the osseous portion of the human body, advanced immensely the diagnosis of bone lesions. Later, with improvement in the technique and more understanding in the interpretation of what the photographic plate shows, other portions of the human anatomy could be examined and at the present time there is hardly an instance of internal disorder to which the aid of the X-ray is not called. Some organs are made opaque by administering mineral substances; in, other cases, conclusions are drawn from barely perceptible shadows on the photographic plate. Generally the surgeon's knife is directed with exactitude to the seat of the trouble and so not only is the difficulty revealed but the necessity for an exploratory' operation is averted.

Jan 1, 1928

By Albert J. McIntosh

In discussing the petroleum products situation the first thing that comes to mind is "what is happening to gasoline." Is the consumption increasing? How is the export market? What about imports? Are stocks on hand too high? Have we produced too much? This paper will attempt to answer these questions. Consumption of gasoline (motor fuel) in the United States in spite of the depression and the chaotic conditions of many industries has increased during 1931 about 2 per cent over 1930. This favorable factor was offset by a severe contraction in exports, which fell off about 30 per cent from 1930. This drop in exports was so large that very little more export business was done than in 1926 or 1927. Taking all demand combined, there was a decrease from the peak year of 1930 of nearly 11,000,000 bbl., amounting to slightly over 2 per cent. The units of the industry, though, should have expected some decrease and governed themselves accordingly. Let us see what they did. They reduced imports over 3,000,000 bbl., which helped. Production was cut 3,000,000 bbl., but this was not enough, so that stocks increased 1,800,000 bbl. whereas during the previous year stocks were reduced 2,500,000 bbl. It is apparent, therefore, that something was done to keep the industry in balance in regard to gasoline, but not enough. If the year had ended on Sept. 30, we could have said that production had been cut 19,000,000 bbl. and stocks had been reduced from the previous year, but the excessive production during the last three months of the year changed everything. It is a strange thing and worthy of note that the price of gasoline fell to its lowest levels when apparently the greatest improvement was being made, and that during the last quarter of the year prices started to improve, when, in spite of an improvement in total demand which approximated 1930, an excessive production caused an uneconomic condition to set in. Stocks on hand on Dec. 31 were unquestionably too high, possibly 10,000,000 bbl. more than was needed for a strong condition to obtain. It seems almost unbelievable that the industry would continue to produce

Jan 1, 1932

By Cornelius Kelley

THE American producers of silver are keenly alive to the importance of the silver problem and its vital effect on the mining industry in Montana and other States where precious-metal mining constitutes a basic industry. There are so many ramifications to the subject that one is tempted, no matter from what angle an approach is made, to digress along lines that inevitably lead into a maze of social, economic and financial problems, through which no clear pathway is marked, and regard¬ing which no definite opinion can be expressed, as the ultimate solution is dependent upon the policies adopted and carried out by the more important Governments with reference to their fiscal requirements and currency systems. The situation may be summarized in two questions First, what, if any, plan have the silver producers, as being the most directly interested, to offer in meeting the situation which will confront the industry upon the termination of purchases of domestic silver under the Pittman Act? Second, what, if any, assistance can be extended by the Government in connection with the problem? In answer to the first inquiry, while the matter has been the subject of discussion among the principal producers, they have been unable to formulate a defi-nite plan, principally because they have been and are dealing with a subject embracing many unknown fac-tors; and second, it has been felt that before any plan is adopted there should be indicated the extent to which cooperation on the part of the Government may be depended upon to enable a proper study of the situation to be made. In order to explain these rather cryptic statements, a general review of the situation may aid. Whatever differences of opinion there may have been in the past upon the subject of bi-metallism or the establishment of a fixed ratio between the coinage value of gold and silver, it will probably be conceded that it would be neither wise nor expedient to attempt a revival of this discussion, nor to undertake to solve the question by the adoption of such a remedy. Issues of contro-versial economics must be avoided, if possible-political economics will destroy rather than assist constructive effort.

Jan 2, 1923

By Nóra Schreithofer, Zoltán Jávor, Kari Heiskanen

"One of the challenges the mineral processing industry is facing is caused by the fact that water resources in mining areas are becoming very limited and the cost of water is increasing. The water sources in arid regions often have high salt content. Environmental regulations are forcing plant operations towards completely closing the water cycles within plants. This means that impurities (salts, reagents, ions dissolved from minerals, etc.) accumulate within the circuit that will affect the flotation performance. Water purification can significantly increase the operating costs therefore it should be carefully considered weather the impurities need to be completely removed or is there a tolerable level of impurities that can still be left in the process water without significant deterioration of the flotation performance? Several additional questions arise: what are the tools that help identify what is a tolerable level of impurities? How do the different impurities interact and what is their effect on the process? The effect of frothers on the dynamic properties of air/liquid interface in different size-scales has been extensively studied by the authors in the past. Based on these studies a frother characterization framework was developed that systematically examines the dynamic surface properties of the air/liquid interface in relation to the bubble size. This work can be considered as tool that could be used for the above mentioned purpose. The present study investigates weather the same frother characterization framework can be applied for systems where both frother and different types of salts are present. Nasfroth 240 was used as a frother, in combination with structure-breaker KCl or structure-maker NaCl and CaCl2. Bubble size measurements in laboratory scale mechanical flotation cell and laboratory flotation column and dynamic surface property measurements (dynamic surface tension and dilatational elasticity) were performed. The results highlighted the addition of salt to the frother solutions significantly decrease the bubble size and increase the froth high. The coalescence behavior of bubbles showed correlation between the D32 and ionic strength of salts. The results highlighted that the studied structure maker and structure breaker salts effect the dynamic surface properties in different way."

Jan 1, 2014