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By R. F. Sheldon

Largest uranium deposit in the Northwest is Dawn Mining Co.'s Midnite mine on the Spokane Indian Reservation. The orebodies lie along the contact of granite and metamorphosed sedimentary rock and are controlled by faults and shear zones near the granite contact. In the oxidized zone the deposits consist mainly of the secondary uranium mineral meta-autunite; sooty uraninite and primary uranium minerals are known to occur at greater depths. Elevations in the mine area range from 2500 to 3500 ft. The rolling hills and low, rounded mountains are covered with grass and evergreen trees. HISTORY AND DEVELOPMENT Original showings were discovered with a geiger counter in the spring of 1954 by prospectors Jim and John LeBret. High radioactivity in several schist outcrops was found due to scaly coatings of a greenish-yellow, fluorescent mineral, later identified as meta-autunite. Prior to this time autunite was not known to occur in the state of Washington, and no significant uranium deposits had been found in the Pacific Northwest. Outcrops in the area were few, and most of the ground was mantled with 2 to 10 ft of overburden, but three other radioactive zones were discovered by prospecting the ridge southward along the strike of the schist near its contact with granite for three quarters of a mile. Midnite Mines Inc. was formed

Jan 1, 1960

By Irwin Remson

Some unique hydrogeologic issues are inherent in the problems of siting, designing and licensing a mined geologic high-level nuclear waste repository. The problems involve hydrogeologically unfamiliar rocks for which little proven technology has been developed, long containment periods, elevated temperatures, and externally-imposed management constraints. In evaluating the existing national program, it should be recognized that hydrogeology is only one aspect of the total nuclear waste disposal problem, that the use of multiple barriers requires that the hydrogeologic system be considered in its entirety as a total system, and that engineering modifications can improve the isolation capabilities of certain barriers. Important research questions involve the mechanics of transport through dense fractured and unfractured rocks, methods for measuring vertical hydraulic conductivity, and a variety of geochemical questions. Current expectations for "high quality data" from either in situ or laboratory testing are unrealistic, and a modified approach to repository hydrogeology is needed. The dilemma is that the hydrogeological characteristics that make a potential host rock more satisfactory for respository siting are the same characteristics that are difficult to characterize and make the particular site more difficult to license. Finally, evaluation of the containment potential of any candidate site will become meaningful only with detailed underground exploration, mapping and testing in the host rock formations at the repository levels.

Jan 1, 1984

By G. A. Alers, F. Borik

Rolled sheet products are elastically anisotropic and a large number of measurements of Young's modulus and rigidity modulus are necessary to completely specify their elastic properties. This paper describes and uses a simple measurement technique to obtain the nine elements of the elastic modulus tensor from which all the elastic The elastic properties of a polycrystalline material are usually specified by giving the Young's modulus E and the rigidity modulus G. Unfortunately, these two moduli by themselves are insufficient to completely specify the elastic properties because the rolling process introduces a preferred orientation which makes the material properties can be deduced. In particular, the variation of Young's modulus and the rigidity modulus in the principal planes of a sheet of ausformed steel were deduced. Furthermore, the variation of Young's modulus in the rolling plane was compared with direct measurements. anisotropic. This anisotropy makes E and G functions of the orientation of the test specimen in the sheet so that a complete description of the elasticity requires many measurements on a large number of specimens. A more fundamental approach to the problem is to consider the sheet as a single crystal and measure the elements of its elastic modulus tensor. Although this appears formidable, there have been developed recently high-frequency ultrasonic techniques which yield these tensor elements directly. The symmetry of a rolled sheet is such that it behaves elastically as if it were an orthorhombic

Jan 1, 1965

The regular activities of the Institute are financed mainly by income derived from members' dues, from advertising in MINING AND METALLURGY, and from the sale of publications to the public. In addition, collateral activities and special projects are financed each year by means of income from endowed funds controlled and administered by the Institute. In the aggregate, the amount of these endowments totals more than $684,000. An active effort is being made to increase the endowment funds of the Institute through a standing committee, of which Henry Krumb is Chairman, and of which the other members are: George D. Barron, Cleveland E. Dodge, John V. N. Dorr, Howard N. Eavenson, D. %. Jack- ling, Harvey S. Mudd, Wallace E. Pratt, Milnor Roberts, and Wilfred Sykes. This committee believes that there exists a tremendous opportunity for the Institute to be of evergrowing service to the public, to the mineral industries, and to the profession. It welcomes suggestions as to names of men of means who are vitally interested in the mineral industries, and to whom the opportunity to make a contribution or bequest might appeal favorably if presented in the proper light.

Jan 1, 1946

By Herbert E. Lindberg

Laboratory-scale intact and jointed rock masses were tested in field and laboratory experiments to investigate tunnel response in high stress environments. In most of the experiments the tunnels were modeled by a rigid-plastic foam polyurethane with a crush strength of 3.4 MPa (500 psi) and emphasis was placed on jointed rock parameters: joint sets (single set of parallel plane joints versus a double set of orthogonal parallel plane joints), joint plane angle with respect to the direct loading direction, and joint spacing. Other parameters were loading stress, loading direction, and tunnel reinforcement strength. Results show quantitatively the increase in tunnel deformation in jointed compared with intact rocks, double versus single joint sets, and large versus small angle between the joint plane normal and the loading direction. A surprising result was the decreases in tunnel deformation with increases in the number of joints across a tunnel diameter. The efficacy of scale modeling with laboratory-constructed rock was tested by modeling complex reinforced concrete and steel tunnel reinforcements in jointed rock masses and comparing the results with large scale tunnels previously fielded in highly jointed granite. Tunnel response was reproduced in surprising detail, including concrete fracture, steel liner bending and fracture, and critical load to produce these responses. The scale models also allowed sectioning of the jointed rock masses to observe gross sliding along the joints that accompanied tunnel failure.

Jan 1, 1982

By W. T. Turrall, D. Porter

THE crystal laboratory, Dept. of Physics, Massachusetts Institute of Technology, was confronted with the problem of obtaining a supply of optical grade calcium fluoride (CaF2) for use in growing synthetic CaFe2 crystals. A search of the known fluorspar deposits did not indicate that any quantity of optical spar could be obtained. Even the best material had to be sorted by hand to remove impurities. The process for growing CaF2 crystals developed by Professor D. C. Stockbarger of the Dept. of Physics, M.I.T., necessitates very pure feed materials. Exclusion of impurities is required, even in amounts detectable only spectrographically. The impurities occurred as minute inclusions of SiO2, BaSO4, CaCO3, FeS2, water or air. Crystals up to 4 in. in diam and weighing several pounds are made by the Harshaw Chemical Co. in Cleveland. Since the time required to grow a 4-in. crystal is about one week, and since the cost of manufacture is high, removal of impurities by any concentration method appeared practical. The mineral engineering section of the Dept. of Metallurgy undertook to investigate the possibility of concentrating clear optical fluorspar, -4 mesh +10 mesh, from a feed containing over 99 pct CaF2. Various innovations of the known methods of concentration were considered, but in each case the minute amount of impurities associated with the crystal produced such extremely small differences

Jan 1, 1952

By Frederick Sharpless

THE term "segregation," as here used, means the separation of certain natural resources into groups, consisting of one or more members, with the idea that when thus segregated, each group may be more easily and effectively administrated. We may, for example, consider surface rights as distinct from underground rights, and stop there; or we may go further, and deal separately with timber, water, and agricultural rights, or, going underground, we might deal separately with such groups as precious and base metals, clay, oil, gas, etc. The present paper contemplates only the separation so far as practicable, for administrative purposes, of surface from mineral rights. "Classification," in this paper, has reference to the groups into which the government has divided, is dividing, or will hereafter divide its natural resources; first, into the broad classes of mineral and agricultural lands; and, second, into coal, oil, phosphate, brine lands, etc., the central idea being the separation into natural groups for the purpose of simplifying administration and for the purpose of encouraging maximum development and minimum waste. The two subjects are in some respects quite distinct, but as my argument develops, I think it will be obvious why they are discussed in the same paper.

Jan 4, 1914

By H. H. Haung, J. D. Miller, E. F. Pereira

The chemistry of copper extraction from ammoniacal solutions by hydroxyoxime extractants was studied Equilibrium measurements were made by shakeout experiments with subsequent analyasis of the aqueous and/or organic phases The kinetic experiments were carried out in a single drop reaction cell in order to establish the details of the intrinsic reaction kinetics for this system. Equilibrium measurements Indicated that the extraction involves complete displacement of ammonia ligands from the coordination sphere of the cupric ion by the extractant molecules The extraction reaction has the following stoichiometry

Jan 1, 1981

By D. R. Hanson

The acoustic vibrational spectra of impacted rock slabs were examined at the Denver Research Center, US Bureau of Mines, in an attempt to characterize the behavior of partially detached mine roof rocks. The ultimate goal of this study was to develop a technique or instrument that could provide a quick, accurate, quantifiable measure of mine roof stability. The power spectra of unstable rock slabs were found to contain more energy in the range of 200 to 1000 Hz than solid rock. Comparison of the power contained between 500 and 1000 Hz with that between 3000 and 3500 Hz provided a quantitative measure of rock stability. A lightweight prototype field instrument was designed, constructed, and field tested. This battery-powered instrument computes the power contained in the two frequency bands, compares their magnitude, and displays a number related to the stability of the block tested. Field tests showed the instrument provided reliable measurements of block stability even under conditions of noise that would have seriously degraded the accuracy of the standard methods of roof sounding.

Jan 1, 1986

Calendar of Events

Jan 11, 1961

By L. O. Bond, R. P. Alger, A. W. Schmidt

Well logging provides valuable information for planning coal mining operations. In addition to locating, defining, and evaluating coal beds, electrical logs indicate the relative competence of roof and floor formations. Electrical well logging is the .recording of various physical, chemical, or physicochemical properties of the strata penetrated by a drill hole. To perform logging operations, borehole measuring probes, or sondes, are lowered on a cable into the drill hole. Insulated conductors in the cable pass power to the sonde and transmit signals to the surface. As the sonde is pulled up the hole, the measurements are recorded as a well log. These measurements serve to define the formation lithology. Common rock minerals exhibit characteristic log values such that computer analysis of the log data defines the mineral content of the formations. Shales, carbonates and sandstones, and coal beds are readily distinguished. Furthermore, preliminary results in coal studies indicate the log data delineates variations in ash and moisture contents. Of major concern in planning mining operations is knowledge of roof and floor competence. Here again the logs provide valuable information. Measurements of formation density and acoustic wave velocity provide data for computation of a compressional modulus. This compressional modulus is an effective index of formation competence. Electrical logging thus efficiently provides information for economic planning of mining operations.

Jan 1, 1972

By William E. Souder, Eugene R. Palowitch

INTRODUCTION The longwall method of mining coal underground is now a highly developed and accepted mining technology. However, it was only through a long history of successes and failures that this technology now has the potential for reversing the declining trend in underground mining productivity in the United States. From its early beginnings in the United States during the 1800's, several species of longwalls have evolved. The evolutionary record consists of a series of overlapping birth-death eras, with each era giving way to another unique longwall technology. Typically, an era begins when some new longwall technology appears in response to a new technical opportunity or economic need. This new technology is adopted initially by only a few innovators. Later, other imitators get on the bandwagon and the technology diffuses throughout the user population. But evolving technical demands and socio-economic circumstances eventually cause many of the adopters to discontinue its use. This paper chronicles seven eras in the history of the evolution and utilization of longwall technologies in the United States. Some of the important factors that have influenced this history are discussed. Some distinctions are drawn between the operators who were first to adopt longwalls (innovators), and the imitators who followed. Statistics are presented which show that longwall mining is being adopted at an exponentially increasing rate, substantiating the forecast for a significant number of new longwall installations in' the future. Potential barriers to this increased utilization of long- walls are noted.

Jan 1, 1981

By David Cole

DAVID COLE, EL PASO, TEXAS (communication to the Secretary*).-I have read with great interest Dr. Gahl's painstaking paper giving us the details of development of flotation at Inspiration, and it seems to me that he has covered the ground so completely that there is little to discuss or criticize in connection with his subject. While it was in operation, the test mill in which the campaign was carried on was the Mecca of mill men and metallurgists. There was much to interest students of milling methods in addition to the flotation experiments, and readers of Dr. Gahl's paper will miss the information they hoped to get when the "pilot" mill results were. finally compiled, and I hope that the following remarks outlining from a distance some of the things that happened there will bring forth the rest of the story of the performances recorded in these important experiments. Prior to the use of flotation methods in concentration it had long been recognized that the "unavoidable" losses of sulphides were in the slime which is inevitably produced in the grinding operations required to free the minerals to be separated. Classifying the feed prior to its final stage of treatment had long been in style in milling. This assisted the sand-handling machines and resulted in lowering the tailings made by them, but at the expense of the slime-handling department; and while little was expected of the latter, the wisdom of complicating the process by hydraulic classification was being seriously questioned. Indeed, at the

Jan 10, 1916

By W. G. Pfann

Formation and slow solidification of a molten zone in a homogeneous ingot produces a discontinuity in solute concentration at the boundary of the zone and a gradient of concentration within the zone. By using two solutes, one a donor, the other an acceptor, step or graded pn barriers can be produced. EXPLOITATION of the difference in concentration between a molten solution and the solid which freezes from it is continued in this paper. The normal segregation which results from this difference has been used for purification'.'2 and for pn barrier-formation in semiconductors."4 By means of traveling molten zones this difference has been used to effect multistage separations and to eliminate segregation in ingots." a It will be shown here that by means of stationary molten zones this difference can be used to produce discontinuities in concentration. In particular it will be shown that a pn or npn barrier can be made by the simple act of melting and refreezing a portion of a block of semiconductor, provided that the block contains proper concentrations of a donor and an acceptor in solid solution. Assumptions The operation of melting and slow refreezing will be called remelting and the interface between liquid and solid at the start of refreezing will be called the remelt bormdary. While remelting may be done for various shapes of starting crystal and remelt zone it will be assumed that the remelt zone is cylindrical, its length being measured in the direction of freezing, which is normal to the remelt boundary, and

Jan 1, 1955

By T. W. Guy

DURING recent years, tremendous strides have been made in the economical use of coal. This has resulted in, and to some extent has been a result of, making the fuel specifications more and more rigid. For this reason, all producers have found it necessary to improve their preparation materially, both as to sizing and the elimination of impurities, either by more effective preparation underground or at the tipple and cleaning plant, or both. This cause and its effect in all producing fields seem likely to continue for several years-at least. The splendid inherent qualities of the Pocahontas and New River coals are known all over the world, but their good reputation is only partly due to inherent qualities, and to natural conditions which generally favor loading coal comparatively free from impurities; it is due in large measure to the care and skill used, either with or without the aid of mechanical devices, to ship products consistently low in ash. The first coal from the West Virginia smokeless fields was mined and shipped near Quinnimont, on New River, in 1871, while the first shipments from the Pocahontas field were in 1883. The development of both fields progressed rapidly. At first activities followed the main lines of the Chesapeake & Ohio and Norfolk & Western railroads, and were extended later as branch lines were built from these roads. The Virginian R. R., about 1907, opened up the Winding Gulf territory, which has since become a large producer of smokeless coals from the Pocahontas and the New River measures.

Jan 1, 1931

By M. B. Riordan

A surface indicating pressure, temperature and flow instrument that ernploys variable frequency sensing elements has proved useful in evaluating flow characteristics of wells. Relative productivity of individual oil and gas sands in a given well can be analyzed at several back pressures. The variable frequency sensing elements are an improvement in sensitivity and accuracy and make possible observation of temperature and pressure variations that have not been possible heretofore. The surface indicating featuere results in a more direct approach to solving problems and eliniinate; many assumptions. All three subsurface factors are evaluated, and correlation between them results in a direct means of analyzing reservoir. and well conditions. Surveys have been used to evaluate well performance. locate gas entry In high ratio wells and to investigate gas injection and water flooding conditions. INTRODUCTION In a flowing well that is open to a multiple number of producing sands with varying characteristics. it is valuable to know which sands are producing fluid at a given back pressure and in what relative quantity. Core studies could qualify an interval as productive, and reserves would be computed on this basis. Unless the well is produced so that the interval does contribute. irreparable damage to the interval can occur. It is generally accepted that the optimum condition of pro-

Jan 1, 1951

By M. B. Riordan

A surface indicating pressure, temperature and flow instrument that ernploys variable frequency sensing elements has proved useful in evaluating flow characteristics of wells. Relative productivity of individual oil and gas sands in a given well can be analyzed at several back pressures. The variable frequency sensing elements are an improvement in sensitivity and accuracy and make possible observation of temperature and pressure variations that have not been possible heretofore. The surface indicating featuere results in a more direct approach to solving problems and eliniinate; many assumptions. All three subsurface factors are evaluated, and correlation between them results in a direct means of analyzing reservoir. and well conditions. Surveys have been used to evaluate well performance. locate gas entry In high ratio wells and to investigate gas injection and water flooding conditions. INTRODUCTION In a flowing well that is open to a multiple number of producing sands with varying characteristics. it is valuable to know which sands are producing fluid at a given back pressure and in what relative quantity. Core studies could qualify an interval as productive, and reserves would be computed on this basis. Unless the well is produced so that the interval does contribute. irreparable damage to the interval can occur. It is generally accepted that the optimum condition of pro-

Jan 1, 1951

By E. S. Machlin

The kinetics of vacuum distillation, vacuum-melt surface reactions, crucible-melt surface reactions and boiling are analytically investigated. No disagreement with experiment is obtained upon applying a rigid flow model to describe the behavior of the melt in the vicinity of reaction surfaces. The theory focuses attention upon measureable parameters rather than upon the adjustable parameter, stagnant layer thickness, associated with other theories. The rigid flow theory is thus capable of quantitative evaluation and experiments to achieve this evaluation are suggested. KINETICS, rather than thermodynamics, often determine the degree of refinement achieved in vacuum melting. There is little understanding, however, of the kinetic principles involved in vacuum refining. This paper represents an attempt to achieve this understanding. There are two reactions which need to be con- sidered. The first is the refining reaction. The second shall be called the polluting reaction. It is the reaction associated with the introduction of components of the crucible into the melt. The mechanisms of both reactions are unknown. Many models can be constructed to describe either the refining or polluting reactions. For example, consider the refining reaction C + Q = CO(g). One model that can be imagined is that the carbon and oxygen combine in the melt to form CO which then diffuses to a melt-

Jan 1, 1961

(Under this heading will he published notes sent to the Secretary of the Institute by members or other persons introduced by members.) No. 488.-Mining engineer, member, technical graduate, married, age 38, desires position of superintendent or assistant superintendent. Has had 15 years' practical experience as miner, millman, machinist, surveyor, engineer, foreman, and superintendent in the West, Southwest, and Mexico. Speaks Spanish. Now employed as superintendent of copper property in Southwest. Can give the best of references. Minimum salary $250. Available now. No. 491.-Mining engineer, member, married, age 43, desires to connect with some-good coal company as superintendent or manager. Is thoroughly conversant with flat and pitching systems of coal mining. Has had 23 years experience from the bottom up; 7 years experience as superintendent and manager. Good organizer. Has handled all classes of labor acid has always made good. Available now. No. 492.-Metallurgist and chemical engineer, member, with 8 years executive experience in research and technical direction of all departments of nom-ferrous metallurgical manufacturing, is open for change in position. Specialist in raw materials-and supplies, reclamation of wastes, and standardized control of processes. No. 493.-Member, age 37, technical education, married. Seventeen years' experience as superintendent, engineer, chemist, and assayer, exploration engineer in United States, Central and South America, Siberia and India. Especially in iron, manganese, copper, and rare metals. Desires to make a change. No. 494. Electrometallurgical engineer, member, age 30, A. M. and Ch. E. degrees, thoroughly trained in electrochemistry, metallurgy and electrometallurgy. Three years in charge of experimental work on and operations of electric furnaces. Desires responsible position in investigative or executive work with commensurate salary.

Jan 11, 1918

By Blamey Stevens

The object of this paper is to show how igneous intrusion is governed by definite mechanical laws. A distinction is made between dikes and fissures, and the various characteristics of intrusions are explained on an exact scientific basis. The modification of rock-stresses by intrusion is then considered and extensive isostress regions are recognized. Finally, a complete classification of intrusions is constructed covering all possible cases. The generalizations of observed data, taken from Geikie's Text-Book of Geology, confornl to the laws of intrusion herein stated, and the deductions based upon these lams. No authority, however, is quoted for the type which I hare named a corrugated intrusion. Its existence is a necessary deduction from the laws of intrusion, and even the entire absence of examples in technical publications cannot disprove its reality. In all probability, corrugated fissures would have remained undiscovered, but for the nrorking of mineral veins. As intrusions of tabular form are seldom worked for commercial purposes, it has been left for theory to anticipate the discovery of corrugated dikes. In the light of these laws of intrusion and the corresponding laws of fissures,' there seems to be a remarkable uniformity of stress-distribution in rocks at moderate depths. This renders possible the mathematical calculation which should help us to approximate exact science in this and kindred branches of applied geology.

Jan 1, 1911