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INTO their great Pacific Northwest counting house went the members of the Industrial Minerals Division recently, to count their blessings amidst the scenic grandeur and mineral wealth of the State of Washington. From their vantage point in Seattle, those who attended the IMD's fourth Pacific Northwest meeting turned their sights to the South and Southeast, scanned Montana, Idaho, Oregon and Utah, and predicted a very healthy economic future for their region. The praises of Idaho's booming phosphate industry were sung by Earl W. Murphy, secretary of that State's Chamber of Commerce. He said the establishment of Fort Hall, on the banks of the Snake River near Pocatello, first turned the eyes of the world toward what is now the center of the greatest known deposits of phosphate rock-the section adjacent to the common corners of Idaho, Wyoming and Utah. With the founding of Fort Hall, Mr. Murphy said, historians will also rank the construction of the first electric furnaces for the production of elemental phosphorous as equally significant in the commercial history of the West. Those furnaces were installed only last year by the Westvaco Chemical Div. of the Food Machinery & Chemical Corp. at Pocatello, at a cost of $8 million.

Jan 7, 1950

By Maurus Seet

Mainland China, with one-fourth of the world's population and one-tenth of its coal production, can no longer be ignored as a considerable force on the world energy scene. In terms of annual productivity, China's 300 million tons of coal rank third behind the Soviet Union with 655 million and the United States 557 million (1968 Minerals Yearbook. USBM). When viewed from another angle, 1967 figures show that increased productivity from all coal-producing continents, with the exception of North America, was led by Chinese-dominated Asia with a 19% gain. Not unpredictably though, China, on a per capita basis, is closer to the bottom of the list among members of the industrial community. Despite its misspent youth, and despite the set- backs caused by the Big Leap Forward of the late 50's and the Cultural Revolution of the late 60'S, the People's Republic has managed to make some impressive strides in developing its coal industry over the past twenty years.

Jan 1, 1971

By S. S. Clarke

THE opening of sheet-ground mines in which the ore beds are only from 7 to 9 ft. thick led the Commerce Mining and Royalty Co. to con-sider mechanical loading, in order to avoid the high cost of hand shovel-ing in such mines. Scraper loaders were chosen because the capital investment would be comparatively low; because they are small enough to be used in low working faces, and because they can be mounted on a mobile carrier.

Jan 1, 1939

By Ali M. Heidarieh Zadeh, Raghu N. Singh

The paper presents a stability investigation of shaft intersections and pit bottom roadways in the vicinity of upcast and downcast shafts at a colliery in the U.K. Aschemeof instrumentation was aimed at monitoring the strata displacement surrounding the pit bottom roadways and shaft intersections with a view to ascertaining the origin of the strata movement and effectiveness of the control measures. The bore- hole instrumentation results together with a theoretical analysis suggested that the cause of instability could be attributed to the drivage of a roadway within the shaft pillar. A semi-empirical technique was used to calculate the amount of support resistance required to reinforce the pillar to take additional abutment load. A rock bolting system was designed to provide a required increase in thrust capacity of the roadway support. The results indicated that roadway closure was effectively controlled after installation of bolts indicating efficacy of the control measures adopted.

Jan 1, 1982

By B. I. Routh

A STUDY of the effects of temperature on the gel strength of drilling muds is a natural outgrowth of the present era of deep drilling. The control of the gel solids' is now considered important because it affects the wall-building qualities; the suspension of weighting material; the removal and release of sand, cuttings, and gas; and the control of cav-ing formations. With regard to the effect of temperature on gel strengths Herrick2 states: "Temperature variation within ordinary limits does not have much effect on yield points." Lewis, Squires and Thompson3 investi-gated one clay and found no marked change with temperature in either yield point or mobility. Reed4 found that potassium bentonite showed a great increase of gelation with increase in temperature and qualitatively there occurred a marked increase in viscosity upon heating. The apparatus used in these experiments consisted of a Stormer viscosimeter, Marsh funnel viscosimeter, rectangular and cylindrical shearometers, Mudwate hydrometer, and other minor laboratory equip-ment. The various methods of measuring viscosity and gel strength have been extensively described by Evans and Reid.5

Jan 1, 1938

By John J. Strohl, Henry J. Schwellenbach

This paper relates the results obtained by decreasing the size of feed to a rod mill screen circuit. As would be expected, added production was gained and a finer grind with no tonnage loss was made possible.

Jan 12, 1950

Jan 1, 1969

THE opening session* was held in the hall of the Franklin Institute, on Tuesday evening, June 20th, President Holley in the chair. The President introduced. Mr. Franklin B. Gowen, who addressed the Institute as follows MR. PRESIDENT AND GENTLEMEN : It has been made my pleasant duty to welcome you to the city of Philadelphia, but in so doing I shrink, with some natural reluctance, from appearing before an audience so much better fitted than I am to cope with the subjects which are usually presented to your association, and I can assure you that no trembling neophyte, first venturing within the groves of the Academy, or walking, with sacred reverence, in the gardens of Plato, felt more natural dread at the consequence of his own temerity than I do in appearing before an audience composed of gentlemen belonging to a scientific society of which I am but too sensible that until now I have been a member only in name. In olden times, upon entering a temple sacred to the worship of any deity, it was customary to lay some offering upon the altar, and, in following this custom, it will be my duty, before entering upon the more pleasant part of the task which is assigned me, to call your attention to a subject with which I have been somewhat familiar, and which is entirely within the scope of your investigations, in the belief that I may throw out some hints or some suggestions of a pro¬cess that may be fully developed by some of you, and eventually lead to the introduction of that which may be of service to the human race. The satirist who described the philosopher whom he met, as engaged in the process of extracting sunbeams from cucumbers, * A joint discussion of the subject of Technical Education, by the members of the American Society of Civil Engineers and the American Institute of Mining Engineers, was held in the hall of the Franklin Institute, on Monday evening, June 19th, and Tuesday morning, June 20th. This discussion has been printed in a separate pamphlet by both societies.

Jan 1, 1877

By Folke H. Kihlstedt

Geophysical prospecting for ore has been more or less at a standstill during the present crisis owing to the lack of interest in base-metal exploration. A notable exception is the increased use of electrical and magnetic methods in prospecting for gold, the former in Canada, United States, Sumatra, Africa and Western Australia, and the latter on the Rand. This application to gold prospecting marks a forward step in ore prospecting because it is based upon mapping the geology instead of a direct location of the ore in question, as the amount of gold in an average gold ore is far too small to have any influence upon the physical properties of the rock in which it occurs. The development has thus gone in the same direction as geophysical prospecting for oil; that is, to find geological conditions that are genetically connected with the gold ore as exemplified by known occurrences. Naturally the success of this indirect prospecting depends upon two things: (1) the soundness of the geological conclusions upon which is based the hope of discovering new deposits, because a great many geological "set-ups" are barren, and (2) the ability of geophysical methods to help the geologist to collect the pertinent geological data within reasonable cost, after which favorable structures may be drilled or trenched. The first point is one to be considered by the mining geologist. In the vicinity of producing mines or promising prospects, the chances of finding ore in quartz veins and shear zones are great, and a survey giving the location of these features will materially guide both surface and underground exploration. Even in outside exploration the chances are sometimes favorable. As an example may be taken the Northeastern Ontario-Western Quebec gold zone. Large areas are here covered with glacial and post-glacial deposits and a simple study of available maps reveals the fact that less than 30 per cent of the area can ever be even preliminarily prospected by cominonly used prospecting methods, of which the pick and shovel are the main tools. Considering the number of deposits found, it is evident that many deposits remain hidden below the overburden. The knowledge of gold geology gives a starting point

Jan 1, 1934

By William Hilliard

IN any manufacturing business, it is of vital importance that the management should know the exact cost of the units of production. Without such knowledge, a company can sell blindly in the open market, obtaining the best prices it can in competition with other firms, and manage perhaps to continue in business for a time; but at any moment, and especially in a period of falling prices, such a firm is at a loss to know exactly at what point it can sell at a profit and exactly how much it is losing per unit if it sells below that point. Furthermore, it is necessary not simply to know the exact total cost per unit, but to know definitely all the different-factors which enter into that cost. A firm manufacturing pocket knives had been doing a profitable business for many years when it began to earn smaller and smaller profits, until there was scarcely any profit at all being realized. Being unable to determine exactly what its future policy should be, it called in experts who studied the past records carefully and followed out for a period a better cost, system. Investigation then showed that on several different kinds of knives in common use, a small profit per unit was being made. On a number of special kinds of knives, of which the firm was very proud, it had been forced to cut prices under the pressure of outside competition and had believed that a small profit per unit was still being made on that product, while a detailed cost analysis showed that a loss was being incurred on each knife of that kind produced. It then became clear that the company must either give up the special line and concentrate wholly on the cheaper knives and extend their sales to territory not yet developed; or expand its plant and produce more of the higher grade knives and thus lower the cost per unit enough to make money on the higher grade knives also, if conditions warranted such expansion. Investigation revealed that the market for large quantities of the high-grade -knives was decidedly uncertain and that the most promising move would be to manufacture only the less expensive knives on a larger scale. That plan was carried out and the concern began again to make a better profit.

Jan 1, 1932

By C. F. Nagel

THIS paper is written primarily for those who are familiar with the processes mentioned but who desire a further insight into some of the fundamental principles. It does not give a complete description of the various practices employed in the working of aluminum and its alloys, but presents a few illustrations of the essential respects in which aluminum differs from other common metals, and emphasizes the controlling factors of the processes under consideration. HEAT TREATING Certain aluminum alloys are capable of having their mechanical properties greatly altered by a heat-treatment process. The degree of this improvement may be illustrated by some typical properties of duralumin (Table 1). It is essential that the material be in the wrought condition in order to obtain maximum heat-treatment effects. [ ] In the case of duralumin, the process consists of heating the metal to a prescribed temperature and then quenching it. Immediately after quenching, the material is relatively soft though not as soft as in the annealed state. If allowed to stand at room temperature, the material changes, increasing in hardness and strength without loss of elongation, but at the expense of the plasticity. This action is very rapid at first, gradually diminishing in intensity and to all practical purposes being completed in about four days. This process of hardening is termed

Jan 1, 1928

Jan 1, 1935

By Thomas Harris

This paper. was written in conjunction with the work being undertaken by the Technical Committees on Classification of Coal, and an effort has been made to compile information relative to the use of coal for stationary steam generation in order to use this information to assist the Committee on Classification of Coal for the ultimate purpose of elimination of losses both by the' reduction of indivi-dual effort and waste in the consumption of material. Under the auspices of the National Association of Purchasing Agents, a questionnaire was drawn up to develop this information from stationary steam plants throughout the United States. in order to consolidate the information de-veloped from the many hundreds of boiler tests on coals consumed by various coal¬burning equipment. These questionnaires covered: 1. The company reporting, location and method of delivery to the plant. 2. Complete coal date, including description of coals used (with. sufficient space to- include first, second and third, preference) on--source of coal used,- complete-analysis and factors affecting choice of, coal used. 3. Plant data, divided into - A. Hand fired, B. Overfeed stokers,. . C. Underfeed stokers, D. Traveling grate stokers, E. Pulverized coal, and included complete description of furnace data, draft data, coal-burning rate, type of stoker, type of pulverizer, efficiency date and remarks.

Jan 1, 1933

Jan 1, 1881

By W. H. Davitt

While it is true that taxes, especially income taxes, whether they be federal, state, or local, are not usually thought of as a "cost" of doing business, it is equally true that these tax costs do reduce the distributable profits just as much as the cost of power, supplies, or labor. Therefore, the consideration given to taxes is often as important as that given to other costs. Hopefully you will recognize that, within certain limits, taxes can be controlled to an economic advantage. The tax laws as now imposed are quite complex. Many of these laws and the regulations thereunder involve many factual determinations, technical considerations, and specialized valuations that can best be made by people trained in the specific area concerned. A substantial amount of a tax liability turns on the proper consideration given to issues involving facts and principles which are peculiarly engineering in nature. The importance of these "engineering" issues in tax administration has been significantly increased in recent years by our rapidly advancing technology, automation, stepped-up mineral and oil exploitation, new industries such as electronics and nuclear power, and the extension of percentage depletion to all minerals. These specialized requirements incorporated in the law are so technical that full consideration can not be given by people with a non-engineering background.

Jan 7, 1974

The Library of the above-named Societies is open from 9 A.M. to 9 P.M. on all week-clays, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining-reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 4, 1913

By Thomas M. Drown

THE means relied on to attain uniformity in Bessemer steel may be enumerated as follows I. The appearance of the flame. II. The appearance of the slag. III. The spectrum of the flame. IV. Examination of the steel itself. At present, I wish briefly to bring forward a few considerations with reference to the last two mentioned, namely, the conditions favoring the employment of the spectroscope and examination of the steel. From the amount of careful investigation which has been devoted to the examination of the Bessemer flame by the spectroscope, both on the part of scientists and practical metallurgists, one might reasonably expect some results definite and satisfactory in their nature, first, as regards the nature of the flame, and second, as to the practical value of the spectroscope as a guide in conducting the process. We find, in fact, however, that uncertainty and confusion still exist. In Germany, where this subject has received the greatest attention, it is now very generally conceded that manganese is the cause of the well-known groups of dark bands that characterize the Bessemer spectrum. Nor is it easy to see how we can avoid accepting this conclusion, when Wedding and Von Lichtenfels have produced the manganese spectrum and found it to correspond closely with that shown by the Bessemer flame. But it is evident, on a moment's reflection, as Roscoe has recently brought forward, that manganese cannot be the only cause of the Bessemer spectrum, for we notice the characteristic bands quite as

Jan 1, 1873

By P. E. Senseny

INTRODUCTION Massive hydraulic fractures have been used since 1949 in the petroleum industry to enhance production rates and increase recoverable reserves. Currently, a research program, the Multi-Well Experiment, is underway to develop the understanding and technology to a1 low economic production of the large gas reserves of the low permeability, lenticular sandstone formations in the western U.S. (Atkinson, et al, 1981; Northrop and Sattler, 1983). Use of state- of-the-art hydraulic fracturing techniques is a part of this investigation. As a portion of an extensive core program in support of this experiment (Sattler, 1983), fracture toughness has been determined for 56 sandstone, shale, mudstone, or siltstone horizons from three wells in the Piceance Basin. The role of fracture toughness in hydraulic fracturing is not well understood because other factors, such as in situ stress, dominate fracture geometry and containment. Rubin (1983) concluded from analysis of his laboratory hydrofracture experiments that fracture toughness should be included in design and numerical simulation of hydraulic fractures. However, van Eekelen (1982) contends that the stress intensity at the crack front should be so much greater than the fracture toughness of the rock that toughness can have no importance. Generally, fracture toughness and other material properties, such as elastic moduli and permeability, are thought to be of secondary importance in determining fracture geometry and containment. In spite of this, there is a need to acquire a more quantitative understanding of their importance for accurate design and simulation calculations. Analysis of fracture geometry and containment data from hydraulic fracturing experiments carried out in formations where fracture toughness and other rock properties are

Jan 1, 1984

By Karl S. Kurtenacker

In attempting to find a rapid and economical means for solving many of the subsurface problems that confront the highway engineer, the author for the past two years has utilized a Megger Ground Tester on resistivity surveys in conjunction with highway construction. Electrical surveys in connection with highway work are largely shallow depth surveys, thus differing from most other types of resistivity work. Consequently, the readings are affected by a great many qualifying factors such as the density and moisture content of the media under observation and the amount of weathering and leaching. In most cases the surface layer is decidedly heterogeneous in character, and, because of the great number of side hill cuts, the second layer, which in most cases is rock overlain by some sort of surface soil, silt, or debris, seldom lies in a horizontal position. Shallow strata, lacking homogeneity and not lying in a horizontal position, do not lend themselves readily to accurate theoretical interpretations, therefore the author has used empirical rules to a large extent in interpreting depth soundings. The following empirical rules of interpretation are surprisingly adequate for highway work, since much of the work is in the nature of reconnaissance surveying and the results are construed to be approximations. The writer is careful not to risk interpretation on some special feature of the curve, since such features are usually due to random errors or lack of homogeneity among the subsurface strata. Effect of Surface Medium A resistivity depth sounding taken to a depth of 200 or 300 ft. is not much affected by superficial conditions, but these conditions have a great effect in depth soundings to 25 or 30 ft. In shallow soundings the character of the surface medium has a very marked effect on the entire resistivity graph. Fig. 1 illustrates a very striking example. Graphs A and B are depth soundings taken in approximately the same place. The surface stratum is a clay loam but at the place where graph B was taken

Jan 1, 1934

By Charles Barrett

THE orientation of metal crystals and grains, both large and small,. can be determined conveniently and accurately without the use of X-ray apparatus. This seems to be appreciated by so few metallurgists that it may be useful to explain in detail the method we have found most satis-factory in the laboratory the reflection of light from crystallographic etch pits. This note includes a description of a suitable inexpensive instrument and instructions for etching various metals and for plotting the data. As the stereographic projection is used to facilitate handling the data, this note may be considered as an appendix to an earlier review of the metallurgical uses of the stereographic projection.1 Various methods involving etch pits have been used by other investi-gators, Bridgman's method2 consists of attaching the specimen to a sphere (a transparent sphere is convenient4), holding it at arm's length, and marking a spot on it when it has been turned so that the etch pits reflect light into the eye of the observer from a lamp standing behind him. It has an accuracy of about 2° and is extremely rapid. A greater accuracy can be obtained by having the reflected light fall on a screen, as has been done by Czoehralski, 5 Chalmers,6 and Schubnikov.7 All of these methods have been intended for undeformed single crystals. Tammann and his coworkers"' developed a method for estimating the number of grains in a polycrystalline aggregate having orientations in a given region of the stereographic triangle and thus obtained statistical information about deformation and recrystallization textures. While the method has had some use in recent years,9 it is not applicable to the majority of problems in physical metallurgy. Smith and Mehl10 determined orientations by plotting the directions of the sides of individual etch pits on a stereo-

Jan 1, 1940