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A large body of porphyry-type copper mineralization occurs at Panguna in southern BougainviIle. It is associated with the intrusion of quartz diorite/granodiorite into andesites, particularly with the contact zone. Metasomatism of both intrusives and andesite resulted in the formation of biotite pseudomorphing hornblende and the veining of the resultant biotite diorite and biotitized andesite by quartz-chalcopyrite veins with pink orthoclase and dark biotite selvages, respectively.The orientation of intrusives and veins appears to be controlled by premineralization fault-joint patterns in the intruded andesitic Kieta Volcanics.

Jan 1, 1968

By A. D. Huffman

This paper covers the major salt deposits of Canada, with a brief summary of the early history of the industry and a more extended outline of progress since the second world war. Both dry mining and solution mining are covered, and the future of salt mining in Canada is discussed.

Jan 1, 1968

By Hal T. Morris

The main Tintic mining district in central Utah has produced approximately 13,500,000 tons of ore, containing silver, lead, gold, copper, zinc, and other metals, valued at more than $315,000,000. More than 90 per cent of this ore has come from large, irregular ore bodies that have replaced folded and faulted limestone and dolomite strata. Of lesser importance are replacement veins that chiefly cut contact-pyrometasomatized carbonate rocks and fissure veins that cut altered intrμsive bodies and volcanic rocks. The district is in the west-central part of the East Tintic Mountains, a north-trending fault-block range near the eastern margin of the Great Basin. The consolidated sedimentary rocks exposed at the surface and in mine workings are miogeosynclinal deposits more than 10,000 feet thick that range in age from late Precambrian to Late Mississippian. They are folded and strongly faulted and are partly overlain by volcanic tuffs and agglomerates and by extensive flows of porphyritic and vitrophyric quartz latite, latite, and trachyandesite of Eocene age. All of these rocks are locally concealed beneath thick alluvial deposits of Pliocene and Quaternary age. The Eocene and older rocks are cut by dikes, sills, and small stocks of porphyritic quartz monzonite, monzonite, and latite, which are genetically related to the ore deposits. The district is inactive except for the production of halloysite clay and for minor leasing activity and exploration ventures. Several exploration targets remain untested.

Jan 1, 1968

Regions with extensive reserves of brown coal but with inadequate deposits of hard coal provide a particularly suitable field for the application of brown coal petrology.In fact, this discipline is indispensable where brown coal is to form the basis for high-quality products of upgrading. Both chemical and physical analyses are required in addition to the techniques employed in coal petrology, but it is the macropetrographic and the microscopic investigations that are of decisive and specific importance.Foremost among the methods of upgrading brown coal is briquetting. From the raw materials aspect the biochemical rank of coal (i.e. the type of deposit) and the coal variety (i.e. the lithotype) exert a marked influence on briquette strength. These are also the significant factors in the suitability of a brown coal for high temperature carbonization; here the demands on coal quality are even more exacting if adequately sintered and therefore high-strength lump chars are to be obtained. The principle applies also to the char from low temperature carbonization. There are close relationships between the tar yield and the remission of the coal.The reflectivity measurement therefore provides a rapid method for evaluating the suitability of a brown coal for low temperature carbonization. Similar correlations have been established between the content of extraction bitumen (raw montan wax) and the remission. Petrological investigations show that the quality of the coal bitumen is a function of the type of deposit and of the lithotype.

Jan 1, 1968

By Sidney Katell

This report, covering the period January 1967 through December 1967, is a continuation of a series that began with the publication of Information Circular 7516 in October 1949. It is the ninth in a series of reports prepared in cooperation with the American Association of Cost Engineers. The abstracted articles are concerned with all phases of cost engineering in the field of chemical and petroleum plants and related subjects. They are from the following sources: 1. American Association of Cost Engineers Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress. 6. Chemical Week.

Jan 1, 1968

By Harold M. Smith

This publication summarizes the literature on the composition of petroleum, with special emphasis on naphtha and gas oil, and provides a source book for the known qualitative and quantitative facts on crude oil composition. The discussion points out the known facts from supposition, and suggests new researches needed in various areas.

Jan 1, 1968

By William R. Barton

Sampling to determine development potential of beryllium deposits was conducted at 31 New England localities. A total of 54 additional areas where the geochemical environment appeared favorable were sampled to determine if economically interesting percentages of beryllia (BeO) might occur. Newry Hill-Plumbago Mountain, Maine, Iron Mountain, N.H., and Long Island, Maine, were investigated in some detail to determine the size and grade of deposits. The mineralized pegmatites at Newry Hill-Phunbago Mountain are extensive but very low grade; at Iron Mountain the ore bodies are very rich but of small volume; at Long Island beryl occurs with molybdenite, wolframite, and scheelite, but the tonnage of ore was not determined.

Jan 1, 1968

The 1967 Lignite Symposium was held at Grand Forks, N. Dak., on April 27-28, 1967. This was the fifth of these technical meetings and the fourth which was cosponsored by the University of North Dakota and the Bureau of Mines. These symposia have provided a meeting place where current developments concerning technology and utilization of solid fuels (lignite) are presented. There was a registration of 255 persons from 24 States, the District of Columbia, six Canadian Provinces, Germany, and India. Many segments of coal or energy oriented organizations at many levels were represented. During the meeting, 18 presentations were made covering developments in electrical power generation, mining, estimation of reserves, combustion, gasification, and chemical and speciality uses of low-rank coals; these are com-piled in this Information Circular to provide a record of the symposium and to permit wider dissemination of the information. Proceedings of the other meetings have also been published.3

Jan 1, 1968

By John D. Spencer

Air and water pollution and land reclamation relating to coal mining and utilization continued to be featured in research and technologic work on coal by the Bureau of Mines in 1967. Details of the environmental studies are given in this report, along with accounts of other research relating to the mining and utilization of coal. Other studies that were continued during 1967 included health and safety, mine explosives, coal preparation and transportation, coal utilization processes, chemistry and properties of coal, inspection and analysis, and inter-national activities. Publications issued in 1967 are cited throughout the report and in appendix C. Bureau of Mines research centers and laboratories are listed in appendix A, and organizations contributing to or cooperating in the work, in appendix B.

Jan 1, 1968

This dictionary is published by the Bureau of Mines as a contribution to the mining and mineral literature in the belief that it will fill a recognized need. Several attempts have been made over the years to revise Albert Fay's Glossary of the Mining and Mineral Industry which first appeared in December of 1918. Frank L. Hess of the Bureau of Mines worked on a revision, but his untimely death prevented its completion. Subsequently, the writer was employed to compile and edit this dictionary in cooperation with the technical staff of the Bureau of Mines. Fay's glossary contained about 18,000 terms with 27,000 definitions; the present compilation contains about 55,000 terms with approximately 150,000 definitions. These terms are of both a technical and local nature, and they apply to metal mining, coal mining, quarrying, geology, metallurgy, ceramics and clays, glassmaking, minerals and mineralogy, and general terminology. Petroleum, natural gas, and legal mining terminology, unless of a general nature, has been excluded, as has been foreign terminology where there is an English equivalent. Several thousand Spanish-American mining terms that appeared in Fay's compilation have been removed to make way for the thousands of new English terms that have evolved over the years. Those Spanish-American and Mexican terms still used in the Southwestern United States have been retained.

Jan 1, 1968

Helium has probably aroused more varied scientific curiosity than any other single element. Discovered by spectroscopic examination of the sun during an eclipse in 1868, helium is now known to exist not only in the sun and other stars but on earth occluded in minerals, accumulated with natural gases in pockets in the earth's crust, and in the atmosphere surrounding the earth. Astronomers study its presence in the various stars of the universe for clues to their origin and history. Geochemists and geologists study its occurrences in rocks, minerals, and meteorites to determine the age of the earth and the manner of its formation. Pathologists study its effect on living tissues in search for the ideal combination with oxygen for artificial breathing mixtures in medicine, diving operations, and space vehicles. Chemists study its physical properties and use it to trace the sequence of events in reactions in which it does not participate. Geneticists and bacteriologists use it for special studies. Physicists study its behavior when liquefied and the behavior of materials cooled to nearly absolute zero by its use. Nuclear physicists learn more about the universe through study of the nuclear reactions that produce it. Through study of helium and greater knowledge of its origin and properties, science continues to unlock some of nature's more closely guarded secrets. Unknown on earth before 1895, and not discovered as a minor constituent of natural gas until 1905, helium with its simple atomic structure--a nucleus with two electrons orbiting in a closed shell--is a unique element. It is next to the lightest gas, only hydrogen is lighter. It occupies position number 2 in the Periodic Table of the Elements and heads the list of so-called "rare" or ?noble? gases. Most of the naturally occurring helium has an atomic mass of 4.003874 (oxygen = 16). A trace (1.7 x 10-5 mol percent) is the light isotope helium-3 whose atomic mass is 3.0169800 Unstable isotopes of mass numbers 5 and 6 have been authenticated. Isotopes of mass numbers 7 and 8 have been reported, but their existence is less well established. All the heavier isotopes are radioactive and are the product of nuclear reactions.

Jan 1, 1968

By Charles R. Graig

El Laboratorio de Espectrografía del Departamento de Investigaciones de la Cerro de Pasco Corporation, elaboró un método de control de los circuitos de flotación por espectrografía de rayos - X. El método se basa en el uso de técnicas especiales de preparación de la muestra, los productos del circuito de flotación, y la fusión con pirosulfato de potasio. En este sentido, el objeto del texto radica en describir el procedimiento de la determinación cuantitativa por espectrografía de rayos-X, de las concentraciones de plomo, zinc, cobre y fierro en las cabezas, los concentrados y las colas de los circuitos de flotación. Es importante considerar el diseño del laboratorio de rayos X para la elaboración de los resultados de planta dentro del tiempo especificado. Así, el control de los procesos de flotación permite la rápida obtención de resultados exactos, lo cual hará posible una mejor regulación de los reactivos de flotación añadidos a los circuitos, mejorando el proceso.

Nov 20, 1967

By Claudio Alvarez Saenz

El presente texto señala el control de las cualidades físicas y químicas de los pelets preparados de concentrados de magnetita de Marcona, el cual está basado en el estudio de la microestructura de los pellets producidos en la Planta de Peletización de San Nicolás de la Compañía Marcona Mining Co. Para ello, se distinguen el estudio de los factores que afectan la calidad de los pellets quemados, tales como: formación y manipulación de pellets verdes, secado de los pellets, precalentamiento de los pellets y quemado. Además se incluye, aspectos sobre la teoría de las transformaciones que ocurren durante el quemado de los pellets, así como las pruebas experimentales comparativas de peletización y el estudio bajo el microscopio de las microestructuras de secciones pulidas de pellets quemados.

Nov 1, 1967

By J. M. Singer

This study was undertaken to obtain some fundamental information about hazardous mixtures of coal dust and methane (firedamp) likely to occur in mines. Fuel concentration limits for ignition of mixtures of coal dust, methane, and air have been determined by a hot-gas ignition method. The limiting concentration of each of the two fuels was usually less than that corresponding to its lean flammability limit in air. The lean limits of flammability of coal dust vary with the type and size of the dust; in this study coal dust concentrations were less than 80 mg/liter. Ignition jets were turbulent pulses (emerging from a channel of 0.5 cm diam) resulting from explosions of stoichiometric mixtures of methane, oxygen, and nitrogen, Temperatures of the ignition jets were varied by changing the oxygen index (OI) = O2/(02 + Nj2) of the primary methane-oxygen-nitrogen mixture (adiabatic flame temperatures from 2,000° to 3,000° K). The objectives of the study were to establish quantitative relations between concentrations of each fuel at ignition limits of hybrid mixtures and to study the mechanism of ignition of these hybrid mixtures by hot turbulent gases, Empirical equations were fitted to concentrations for four coals, namely) Pittsburgh Seam (sizes A, B, and C), Sewell No.2 Seam, pocahontas No.3 Seam, and anthracite. Equivalences of coal dust to methane were computed from these equations; equivalence being defined as -Ac/Am, where c is the coal dust concentration and m is the methane concentration, each in milligrams per liter of air. It was found that the equivalence increases as the temperature of the hot-gas jet decreases. In general, the equivalence is also an inverse function of volatile content of the coal and a direct function of the particle size, However, volatile con-tent in itself is not a sufficient correlating variable, nor is the specific surface area of the coal dust.

Jan 1, 1967

By F. R. McDonald

This report presents a discussion of the spectra of 39 condensed thiophenes in which the structure includes at least 1 benzene ring. The vibrational bands present in three regions of the infrared spectra of these thiophenes were interpreted by comparing the similarities of the spectra of condensed thiophenes with the spectra of substituted benzenes. In the overtone-combination region 23 of the 39 condensed thiophenes had spectra which contained sufficient detail to be usable for correlating this region of the spectrum with the appropriate benzene spectrum. In the in-plane deformation region it was possible to make correlations for the vibrations of 18 of the 39 condensed thiophenes whose infrared spectra were studied. In the out-of-plane deformation region the C-H out-of-plane vibrations for hydrogen on benzene rings in the condensed thiophenes can be correlated using known data from substituted benzenes.

Jan 1, 1967

By R. W. Smith, R. W. M. Lai

Although several recent papers have shown that equilibrium contact angle in dodecylamine solution-quartz systems can often be directly correlated with flotation behavior, it appears that under conditions of relatively high amine strength and pH such a correlation can't be made. Under these conditions, when there are precipitated amine dipoles present, it appears that a dynamic contact angle formed immediately after introduction of fresh gas bubbles into the system is also of importance. The dynamic angle decreases in magnitude as a function of time. Apparently the decrease is the result of changes in interfacial tensions (liquid-gas and solid-gas) as a function of time. Dynamic angles of the type described can't be observed in trimethyldodecylammonium chloride solution-quartz systems. Several recent papers1-3 have shown quite conclusively that contact angle data can often be correlated directly with flotation behavior in cationic surfactant solution-quartz systems. At the same time, Iwasaki, Cooke, and Colombo4 have shown data for a dodecylammonium chloride solution-goethite system where, in the vicinity of pH 12 and a collector concentration of 10" M, 100% flotation occurs when equilibrium contact angle appears to be zero. A clue to this discrepancy can be found in the work by smith2 who reported the occurrence of dynamic, time dependent, contact angles in a quartz-dodecyl-amine solution system at relatively high pH values and at surfactant concentrations greater than or equal to 10-4 M. It was found that under these conditions, if a fresh bubble was brought into contact with a properly conditioned and polished quartz surface, a large angle was obtained. The large angle, however, instantly started to diminish in magnitude, sometimes to a smaller stable angle and sometimes to its complete disappearance. Also, if the bubble was preconditioned for some minutes (or sometimes even seconds) in the same amine solution, the smaller or sometimes zero stable angle was obtained when the bubble was brought in contact with the quartz surface. One is immediately led to the thought that perhaps it is these dynamic angles when they exist, not stable angles, that are of primary importance in flotation. The present investigation attempts to further study the relationship between contact angle and flotation

Jan 1, 1967

By D. A. Elgillani, M. C. Fuerstenau

With either sulfonate or oleate as collector, quartz responds to flotation with moderate additions of calcium only at moderately high pH, where some portion of the activator has hydrolyzed to caOH+ . Calculations of the concentrations of various ionic and precipitated species of calcium and collectors suggest that the products of [(CaOH+) (RSO3)] and [(CaOH+)(01-)] determine whether flotation is obtained under specific conditions. Ion products on the order of 10-12 were calculated for both the sulfonate and oleate systems. The activating effect of calcium ion in nonmetallic flotation systems is of considerable interest because of the normal presence of calcium in natural water. As a result, this phenomenon has received quite some attention in the past. Kraeber and Boppel1 showed that quartz could be activated by calcium above pH 10 with sulfonate as collector. The feasibility of selectively separating quartz from hematite with calcium activation at relatively high pH was demonstrated by Clemmer, Clemmons, Rampacek, Williams, and stacy.2 Cooke and Digre3 showed with a bubble pick-up method that the minimum quantity of calcium ion required as activator for complete pick-up of particles occurs at pH 11.5 for an addition of 20 mg per liter sodium oleate. They also showed that larger additions of calcium (10-fold increase per unit decrease of pH) must be added for complete bubble pick-up as the pH is reduced. Schuhmann and Prakash,4 using a vacuum flotation technique, found that quartz could be floated with moderate additions of calcium chloride and oleic acid at neutral pH, providing the metal ion was present in stoichiometric excess over the quantity needed to form the normal soap with oleic acid. They also reported that calcium will function as an activator only in basic media. More recently, Eigeles and volova5 have shown that essentially complete flotation of quartz is obtained with 6 x 10-4 mole per liter calcium chloride and 1.7 x 10-5 mole per liter sodium oleate at pH 11.6. while no flotation is obtained at about pH 10.9 and below. The importance of adsorption of activator and collector at the air-liquid interface is also demonstrated in these systems. The important role that metal ion hydrolysis assumes in quartz activation systems was also demonstrated recently.6-8 A detailed investigation of metal activation in sulfonate flotation of quartz was undertaken in one system7 and yielded a number of interesting and important observations. Quantification of the data of this system7 to the extent desired was not possible, though, because certain species could neither be ignored nor accounted for accurately. These difficulties can be circumvented when calcium is involved as activator. This detailed analysis was undertaken to obtain a more quantitative explanation of calcium and metal ion activation in quartz flotation. EXPERIMENTAL MATERIALS AND METHODS Sodium alkyl aryl sulfonate9 mol wt 450, and pure potassium oleate were used as collectors. All other reagents used were reagent grade in quality, i.e., n-amyl alcohol as frother, KOH for pH adjustment, and calcium chloride. Conductivity water, made by passing distilled water through an ion exchange column, was used in the investigation. Quartz was prepared by leaching the sized sample (48 x 150 mesh) with HC1 until no iron could be detected in the leach liquor. The experimental equipment and procedure were the same as that described previously.6,10 EXPERIMENTAL RESULTS As the presence of precipitates was noted in all of the systems to which ca++ and collector were added, experiments were undertaken to determine the solubility products of calcium sulfonate and calcium oleate using a nephelometer. With this technique, collector is titrated into a known solution, which in this case was 5 x 10-5 mole per liter CaCl2 at pH 5.5. Upon precipitation of the calcium-col lector salt, e.g., calcium oleate, light is scattered and detected

Jan 1, 1967

By John J. Reed

This paper was prepared as a supplement to the general review by Dr. N. G. W. Cook. His analysis of the problem in terms of the strain energy involved in making the excavation is excellent. It will contribute much towards a clearer understanding of rock behavior and control. Several of the practical applications described herein can be directly related to Dr. Cook's theories and conclusions, and are based on the very same principles. CONTROLLED BLASTING IN ROCK EXCAVATION Generally speaking, the natural rock is a relatively strong and competent structural material, if we conserve its inherent good properties and perhaps reinforce its weak spots. The difficulty often lies in blasting out the tunnel or chamber without damaging the walls and roof we wish to have remain afterwards. Much progress has been made in the last five years in better understanding the controlled excavation of rock. The specialized techniques known as smooth wall blasting and presplit blasting have now developed from the status of curiosities of rock excavation to the point where these techniques are specified in contracts drawn up for such rock excavation projects as tunnels, underground pourer houses, etc. These techniques have been well described and discussed in previous publications; there is no need to reiterate here. It might be well to point out that recent research has demonstrated the effect that inherent rock stress may have on presplitting in certain directions. Material can be presplit most readily parallel to the direction of maximum compressive stress, and this may not always be in the direction desired. Inherent rock stress measurements by stress relief over coring, etc., may have important value in deciding how to best presplit proposed excavations. In addition, recent work at the Colorado School of Mines has demonstrated the feasibility of con-

Jan 1, 1967

By Richard L. Ash

Usually stresses generated by explosive charges during blasting are considered to propagate through materials in a spherical manner. Although conical stress-waves had been suggested by a few investigators they have never been clearly defined or critically observed. An experimental technique using models and lengths of Mild Detonating Fuse was developed to produce conical stress-waves and study their effects. Several materials with different properties were tested to compare the influence of those properties on wave shape and crater formation. The investigations showed that whenever column charges were end-initiated, conical stress-forms were produced if the explosive's velocity exceeded the energy propagation velocity of the surrounding material. The stress-cone angle significantly affected fragment size and shape as well as the geometry of craters produced.

Jan 1, 1967

By R. T. Keyes, R. B. Clay, L. L. Udy, V. O. Cook, M. A. Cook

Based on compressibility and stress wave velocity in rock, initial explosive loading conditions, the thermochemistry of the explosive and reasonable description of the pressure-distance relations behind the shock front, the distribution of energy between the products of detonation and the burden are estimated as a function of time for various loading conditions. These include 'powder factor', loading density A (fraction of borehole occupied by explosive), and the explosive itself. Factors responsible for rock fragmentation are discussed in terms of: 1) 'release wave fracturing', 2) 'shear wave fracturing', and 3) 'release of loading fracturing' or 'rock bursting'. Release wave fracturing appears to occur only in the immediate vicinity of free faces, and shear wave fracturing only adjacent to the borehole under normal blasting conditions. Rock bursting is thus considered to be the most important means of rock fracturing in blasting. Means for maximizing it are considered. The most important factors to consider include maximum available energy A, explosive density p1, loading density A and 'powder factor'. Maximum efficiency is attained in general by maximizing the A . p1 product. This is achieved by using high density explosives at a loading density of unity (A = 1.0). Ways for achieving this condition are discussed. The bulk-handled aluminized slurry blasting agents have the desired properties for achieving optimum conditions for high blasting efficiency based on the theory outlined herein. Factors considered most important in the blasting of rock are: 1) The maximum available energy A, determined by the heat of explosion Q and the mechanical efficiency ?, a factor intimately associated with the mode of application (A = Q at highest gas concentrations). 2) The 'borehole pressure', pb, or the maximum pressure developed in the borehole after passage of the detonation wave and before the burden has had time to move or become compressed appreciably. (Owing to the short duration of the detonation wave at any particular point in the borehole, the fact that the explosive may not always fill the borehole completely and the further fact that the burden may not actually see the detonation pressure, the borehole pressure is considered more significant than the detonation pressure p2 as a performance factor in borehole blasting.) The borehole pressure is determined by the explosion or adiabatic pressure, p3 , and the loading density, A, or the fraction of the borehole filled by explosive. 3) The physical conditions important in the application of the explosive are: a) The 'powder factor,' (We/Wr), or the ratio of the wt of the explosive to that of the rock being blasted expressed as lb per ton or more generally in lb/cu yd. b) The bulk density, p1 ?. c) The 'burden' or 'line of least resistance,' the spacing between boreholes, the geometry of the borehole pattern and sequence of firing. d) The physical and chemical properties of the rock, most significant of which are possible heterogeneties, such as faulting, prefracture, and greater than micro-scale chemical heterogeneities. (This factor is not considered here but deserves a great deal of careful consideration.) All of these factors need to be carefully considered in the most economical engineering of a blast. Here is considered firstly an outline of the present status of dynamic rock mechanics, particularly as it pertains to blasting. The factors pertaining to the most efficient application of blasting agents are also considered, followed by a discussion of methods of application to achieve optimum explosives performance. ROCK MECHANICS Dynamic rock mechanics is currently a rapidly developing science contributing greatly to a better understanding and consequently the more effective application of explosives in blasting of rock.1-22 Basic to the development of the science of dynamic rock mechanics were the advances of Goransen23 and the Los Alamos and NOL groups24-28 concerning rock and stress wave phenomena and the transmission and reflection characteristics of stress waves at interfaces between different media. Basing considerations on this new knowledge as well as new experimental methods of study (ultra-high speed streak and framing cameras and electronic timers) the theory of fracture and failure of solids under impulsive loading by stress waves developed rapidly.14,16,27-29 Also the

Jan 1, 1967