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By Robert E. Johnson

1962 was the second year of recovery from the mild 1960-61 recession. The year-to-year gain in constant dollar gross national product, our most comprehensive measure of the country's economic performance, was 6.0 percent (from $447.7 billion in 1961 to $474.8 billion in 1962). The unemployment rate declined from 6.7 percent to 5.6 percent. Although it was a good year, there were still unused resources of labor and capital which implied that the economy was operating below its potential. The year-to-year change in the Federal Reserve Board (FRB) index of industrial production of 7.6 percent masked the fact that more than one-third of the growth took place within 196L The monthly index rose only 4.8 percent during 1962, from 114.3 in January to 117.8 in September. The fact that the economy as shown by the industrial index, rose rapidly in the first half of the year only to remain on a plateau of 119-120 during the second half, led some people to fear an imminent downward turn. This did not occur. Neither production nor consumption of mineral fuels advanced as fast as the total economy. But consumption showed more gain than production, 5 percent compared with somewhat less than 4 percent. Production of both crude oil and natural gas reached new highs while bituminous coal production was the highest in 5 years.

Jan 1, 1963

By N Madani, N Battalgazy

Geostatistical simulation has been widely used in mineral resource classification of metalliferous deposits based on international standards such as JORC code which is one of the most extensively used around the world for reporting the mineral resources and ore reserves alongside with objectives of the companies (Sadeghi, Madani and Carranza, 2015). However, the modeling process becomes challenging whenever the relationship between the variables of interest is complicated and cumbersome to model. This characteristic sometimes manifests itself in complex spatial and global cross-correlation measures, deeply depending on the formation and genesis of the deposit. The objective then is to generate the models that not only reproduces these significant characteristics, but also, it leads to a better understanding of a mineral resource estimation and successive decision-makings. In this respect, there are different approaches taking into account the spatial correlation structures, for which can be classified as independent simulation, co-simulation, and factor-based methodologies. In this paper, three techniques: Turning Bands Independent Simulation (TBSIM), Turning Bands Co-Simulation (TBCOSIM) and Projection Pursuit Multivariate Transform (PPMT); from those aforementioned approaches are selected to model two cross-correlated variables (Iron and Aluminum Oxide) belonging to an Iron ore deposit located in Brazil, in order to examine which methodology better reproduces the corresponding complexity in terms of local correlation measure. CITATION: Battalgazy, N and Madani, N, 2018. Mineral resource assessment in complex ore deposits based on international standards, in Proceedings Complex Orebodies Conference 2018, pp 79–81 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By S. Amira

The corrosion behavior of high pressure die-cast and thixocast AXJ530 magnesium alloys has been investigated in 0.05M NaC1 solution at pH 6.0 using potentiodynamic polarization tests, electrochemical noise (EN) technique, electro-chemical impedance spectroscopy (EIS) and scanning reference electrode technique (SRET). The behavior of die-cast and thixocast specimens were compared using each of these techniques and the results discussed. Further tests have been carried out with die-cast AZ91D alloy to better compare and interpret the results. Experiments indicate that the thixocast specimens of AXJ530 alloy have a better corrosion resistance than those of die cast alloy in neutral solution.

Jan 1, 2006

By F. V. Lenel

This discussion is concerned with the method of manufacturing, the design possibilities, and the properties of pole pieces for direct-current electric . motors and generators made from iron powder. In such applications as pole pieces, the electric and magnetic properties of the material are of major importance, therefore they are discussed somewhat more fully. However, the main advantage in making pole pieces from powders lies in the rapid and inexpensive method of manufacturing these pieces, and in the flexibility of design, rather than in their superior electrical properties. As a matter of fact, pole pieces from iron powder have found their principal field of usefulness in small electric motors for controls and similar applications where the highest possible flux density in a given design is not required. Fig. I shows a number of different designs for pole pieces made from iron powder. The steps involved in fabricating them are: (I) briquetting—with each stroke of the briquetting press a complete . pole piece is produced; (2) sintering, and (3) sizing, which is a one-step coining operation in a hand-operated punch press. Conventionally small pole pieces are made from laminated electrical sheet steel stock by punching out the laminations and riveting them together (Fig. 2). The powder method has the advantage of being rapid and inexpensive; also, it makes possible the molding of pole pieces with a round hub, which are better from a design standpoint, as will be shown later. It is difficult to make such round-hubbed pieces from laminated stock. The pole pieces could, of course, be machined from solid stock, but this method is not widely used. The raw material for making pole pieces from powder is straight iron powder without the addition of any alloying ingredients. However, the grade of powder used is of considerable importance, as will be shown later when the influence of the grade of iron powder upon the magnetic properties is discussed. Pole pieces are briquetted in the same way that other iron-powder machine parts are made. Because the pole pieces are flanged—i.e., they have a hub and a wing section—they are made in presses that apply pressure from both ends. For best mechanical and magnetic properties, the density throughout the piece should be even and also should be constant from piece to piece. For that reason a powder of constant compressibility from batch to batch is needed for briquetting pole pieces. One method of obtaining the required magnetic properties is to sinter the pole pieces at temperatures higher than are used for most iron-powder parts. A temperature of 2400°F. and an atmosphere of hydrogen has been found satisfactory. No automatic furnaces of the roller hearth or mesh-belt type have yet been developed for such high temperatures. A box-type furnace heated with Globar heating ele-

Jan 1, 1945

By Luis Huere

La extracción del oro en PAD de lixiviación es una operación que cada vez se utiliza más para la extracción del metal de sus menas, esto se realiza evidentemente por los bajos costos de procesamiento por este método, entre otros motivos. La recuperación del oro es siempre baja comparada con la recuperación por lixiviación en tanques de agitación. La lixiviación de finos siempre es un problema por la canalización de la solución lixiviante y la formación de charcos o “cochas”, generando esto bajas recuperaciones y más aún ante la presencia de arcillas en el mineral perjudican aún más la recuperación de oro de estas menas.

Sep 1, 2017

By Peter Edmunds

Durante mucho tiempo, la perforación subterránea se adaptaba a la energía eléctrica. Actualmente, la transición se sufre en la perforación de la superficie. En este sentido, el presente texto describe algunos aspectos de la perforadora hidraúlica de percusión -en tanto posible perforadora del futuro. Las aplicaciones posibles de las perforadoras hidráulicas de percusión en la perforación de superficie son: la perforación de banqueo de alta producción en canteras, perforación secundaria en minas metálicas a cielo abierto, explotación de minas de carbón a cielo abierto, construcciones importantes y otras obras de ingeniería civil. Asimismo, este tipo de perforación tiene futuro donde la productividad es alta y los costos de rendimiento bajos. De otro lado, al comparar las ventajas de la energía hidráulica y la neumática en la perforación de superficie, se considera como productiva la primera -en tanto existe una mayor capacidad, un mejor ambiente laboral y unos costos de operación más bajos.

Jan 1, 1980

By D. H. Garcia

The mining industry responded to public concerns about use of cyanide by developing a voluntary certification to allow companies to demonstrate their commitment. The International Cyanide Code (Code) establishes standards for the manufacture, transportation and use of cyanide. Key concepts in closure planning to comply with the Code are to decommission all facilities related to cyanide operations and to provide a financial assurance mechanism for those activities. Code requirements may differ from state-specific regulations, but requirements are based on closure goals for protection of the human health and the environment. Only issues related to cyanide operations are required to be included in decommissioning demonstrations. For example, the disposal method of cyanide solution holding tanks and the cost must be included in the closure plan, but information regarding closure of roads is not required. Closure costs must be based on a third-party contractor as opposed to internal budgets. Compliance with the closure requirements of the Code allows companies to show their stockholders, lending institutions, and the public that their operations are environmentally responsible.

Jan 1, 2010

Jan 1, 1960

By Khaled Morsy

In this paper a new method to evaluate the stability of yield pillars was introduced. The evaluation of yield pillar stability was conducted in three steps: (1) Estimation of pillar loading - numerical modeling is a good tool to estimate the pillar loading for most of the geological, geometrical and mining conditions. In this study. finite element technique was used to estimate the state of stress, strain, elastic strain energy and plastic energy, etc. at every point within the pillar. (2) Defining the yield pillar loading zones¬. The proposed method considered the non-uniform stress distribution of yield pillars by dividing the area of the yield pillar into three loading zones, namely core, transition and rib zones. (3) Estimation of stability indicators - an appropriate stability measure was proposed for each loading zone. such as; Core Stability Factor. CSF, Pillar Bump Index, PBI and Rib Instability Index. RIF. A case study of successful and unsuccessful yield pillar application was used to assess the applicability of the proposed method.

Jan 1, 2003

By Tyson G. R

A novel system has been developed using computer imaging techniques to make on-line measurements of material on a moving conveyor. Meas- urements of the mass or volume of conveyor materials are important in large open pit mining operations such as those operated by the State Elec- tricity Commission of Victoria (SECV). Such on-line measurements can be used for monitoring and controlling the production and transport of coal or overburden, and to assist in maintaining production levels. This paper describes a conveyor burden volume measurement system which is currently under development at the Research and Development Department of the SECV and although targeted initially for use in the Commission's open cut mines, the system is suitable for use on any open conveyor system. A basic developmental system has been built to demon- strate the viability of the technique used and further work on the system is planned. The measurement technique and the major components which have been developed as part of the system are described, some comparisons are drawn with other existing measurement systems and potential errors and future development are discussed.

Jan 1, 1989

By T. A. Rickard

INTRODUCTORY. THE presentation to the Institute, eight years ago, of the paper of Pošepny on " The Genesis of Ore-Deposits " has borne fruit in much fresh: investigation, as is evidenced, for example, by the group of very valuable papers, by distinguished members" of the United States Geological Survey, read at the Washington meeting-discussions of general principles particularly suggestive to those who are engaged in mining. Pošepny, in the discussion of his famous treatise, said that the present writer seemed to look at every new conception in ore-deposition" from the sole standpoint of its immediate usefulness in mining."* Protesting mildly against " sole " and "immediate," I accept the impeachment. It calls for no defence. THE DEVELOPMENT OF RECENT THEORIES. Given the idea of an underground water-circulation as the chief factor in the deposition of ore, the next step in the inquiry as to the genesis of such deposits is, the endeavor to determine which particular part of the general water-circulation is responsible for the results. Around this question have centered the controversies of a generation, and to these controversies we owe the gradual clarification of our ideas upon the processes of ore-formation. It is unnecessary to sketch here their progress from Werner to Le Conte, who combated in 1883 the extreme views of the lateral-seeretionists, and in 1893 opposed the narrow interpretation of the ascensionist-theory. The generally accepted opinions of to-day are a well-deserved tribute to his philosophic discrimination. Thanks to Prof. Van Hise and Mr. Slichter, whose work he utilizes, we have now arrived at a comprehensive conception

Jan 1, 1902

By Guilliaem Aertsen

THE derivation of the word tire (or tyre, as it is spelled in England) is obscure. Some dictionaries suggest that it is the aphetic form for "attire, covering," so called as being the outside covering or band of a wheel; also as a corruption of "tier," the band which holds, or "ties," the rest of the wheel together. One dictionary states: "The supposed derivation of the word is that bands were first used on wheels in the City of Tyre, Syria. " In the infancy of railroads, the tracks consisted of flat baits of iron, spiked or bolted to the upper surfaces of longitudinal timbers, which; in turn, rested upon masonry foundations. Stone blocks installed for this purpose on the old Germantown & Norristown Railroad, now the Chestnut Hill branch of the Philadelphia & Reading Railway, were to be seen for many years on the right-of-way, north of what is now. Wayne Junc-tion, Philadelphia, Pa. The "cornerstone" of the Baltimore & Ohio Railroad was laid Apr. 4, 1828, and the first locomotive in America was built by Peter Cooper at the St. Clair Works, Baltimore, Md., in 1829 "to demonstrate its adaptability to a curved road." It is believed that the first successful locomotive was built in Philadelphia by Tyler & Baldwin in 1832 for the Germantown & Norristown Railroad. Rufus Tyler-and Matthias Baldwin were brothers-in-law; the latter's name will he identified with American locomotives until locomotives are forgotten. The Wheels on these first locomotives, designed to run on this primitive rail, were shod with plain iron bands, bent and welded. The flanges consisted. of separate iron bands, bent sidewise, welded, and, bolted to the sides of the wooden follies, or rings. Before many years had elapsed the tires were fabricated of iron bands, rolled in one, piece with the flange projection on the side. The tire for each wheel was bent and welded and subsequently attached to the wheel center by shrinkage, bolts, rivets and various mechanical devices.

Jan 1, 1917

By C. Gravel, A. Fathi, P. Rivard, G. Ballivy, Z. Moradian, M. Quirion

Knowing shear mechanism of discontinuities under monotonic and cyclic loading conditions is a key factor in stability analysis of rock slopes and rock foundations. In this paper, the effect of cyclic loads on the shear mechanism of joint asperities is described. For this purpose, a fresh tension-split joint from a granite block was used as a reference and thirty five mortar replicas were fabricated. Cyclic shear tests were conducted on replicas under low values of constant normal load (CNL) using a servo-controlled loading system. Tests were performed in two consecutive steps; load-controlled and then displacementcontrolled. In the load controlled part, after initial increase of shear stress to 0.25 MPa, the test was stopped for 2 minutes, then increased to 0.5 MPa, and finally decreased to 0.25 MPa. This process was repeated ten times. At the end, the test was continued up to 10 mm shear displacement under displacement-controlled loading in order to pass the peak shear strength and reach the residual strength. Characterizing joint surface and modeling of involved asperities during the tests was undertaken using a Matlab code developed with new mathematical expressions. The algorithm used in the code is based on three-dimensional coordinates of the scanned joints’ surfaces before and after the test. It was found that a high percentage of degradation happens during the first cycle of loading and during the other cycles, degradation occurs gradually. While comparing tests conducted in monotonic and cyclic loading conditions, it was observed that under low number of cycles, the pronounced mechanism is consolidation of the joint surfaces. This consolidation increases contact areas and, therefore, shear strength parameters.

Jan 1, 2015

H. S. COE, St. Louis, MO. (written discussion *)-I feel much gratified that Mr. Mishler has confirmed those principles of slime settlement expressed by Mr. Clevenger and myself. I wish to state that, when we wrote the article referred to by. Mr. Mishler we had not seen his earlier article in which he gave a formula to be applied to the settling rate off feed pulp for determining thickener area required at El Tigre. It has been my experience that in cyanide work the settling area required is determined by the settling rate of the feed pulp for perhaps 20 per cent. of all of the ores to be encountered. For the other ores, the area required is greater than that indicated by the settling rate of the feed and corre-sponds to the settlement of a somewhat thicker free-settling pulp. Mr. Mishler, in his paper, has thoroughly outlined a set of tests for determining thickener capacity, which, if carefully carried out, should be entirely reliable, provided allowance is made for changes in the mill feed from time to time. Two features of his paper, I, believe; need comment. In speaking of the time required for slime to flocculate after being fed, Mr. Mishler quite properly states that the actual settling rate for the feed pulp can-not be that of completely flocculated pulp because of this time lost in flocculation. It seems to me, however, that this feature cannot be of very great importance, for the following reason: The upper zones of pulp in a thickener may be, and often are, as thin as the feed pulp. If, therefore, the feed be introduced at sufficient depth below the pulp surface to prevent agitation at the surface, there will be ample time for it to become flocculated before it becomes the surface layer, and it, will

Jan 1, 1918

By W. H. Emmons

MANY mineral veins occupy faults, and movements on certain warped fault planes have resulted in openings. On normal faults the [ ] steeper parts have the widest openings, and on reverse faults the flatter parts have the widest openings. Theoretically the width of the opening is the sine of the angle of deflection times the amount of movement on the fault plane, but actually the widths of some of the openings are probably less because of readjustments of walls along joints or of other readjustments. The first treatment of the subject seems to have been in a book on mineral veins by John Leithart, published in Newcastle, England, in 1838. Later the subject was treated in various texts published in Germany, in England, and elsewhere. The subject was not given much prominence in the earlier American literature on economic geology, but has interested several workers in that field in the past decade. In this paper examples of districts showing ore shoots on warped faults, with relations noted, are described. Fault veins of the three depth classes of veins are noted. Many epithermal veins are in normal faults, and commonly the larger ore shoots are in their steeper portions. Many mesothermal veins are in reverse faults and many others are in normal faults. The flatter parts of veins in reverse faults are commonly wider than the steeper parts, although they are not always as rich as the steeper segments of the veins. There are not many hypothermal veins in faults of measured displacement.

Jan 1, 1943

By D. R. Spink

In the preparation of zirconium and hafnium metals, there are many indications that impurity levels control the physical and chemical properties of the metal. The purpose of this work was to develop methods of producing pure raw materials that could be reduced to highly pure metals. Early work by the Carbomcndum Metals Co. and others indicated that certain fused salts were highly efficient in the removal of impurities from gaseous zirconium tetrachloride. We have developed workable fused salts along with a continuous and higly efficient scrubber design which can be used to produce very pure zirconium tetrachloride. Metal made from the purified tetrachloride has been shown to approach crystal bar metal in purity. Scrubber designs are discussed with recommended materials of construction. VARIOUS methods have been used to purify zirconium (and hafnium) tetrachloride. Most of these methods involve thermal degassing initially (the removal of more volatile compounds at temperatures below that where zirconium tetrachloride exhibits a significant vapor pressure) followed by a sublimation step (which conveniently leaves the nonvolatiles behind.) While these procedures effect definite purification, such processing is batchwise and does not result in optimum purification. Early work by The Carborundum Metals Co. and others indicated that fused salts were highly efficient in the removal of impurities from gaseous zirconium tetrachloride. The objective of this work was to develop a continuous fused-salt scrubbing process that would yield high-purity zirconium and hafnium tetrachlorides. The term "fused salt" refers to the molten state of ionic compounds and as used here, specifically refers to alkali metal and alkaline earth halides. Fused salts, because of their many valuable properties, are becoming increasingly im- portant industrially. These valuable properties of the fused salts are: 1) stability at elevated temperatures; 2)low vapor pressure; 3) low viscosity; 4) ability to dissolve many different materials; and 5) good elctctrical conductivity. All but the last property enhances the use of fused salts as scrubbing agents for zirconium and hafnium tetrachlorides. Fused-salt scrubbing may be defined for our purpose as the intimate contact between a gaseous compound and a molten salt with the purpose of removing impurities from the gaseous compound. In this case, the gaseous compound is zirconium tetrachloride which submlimes at 331°C. When this gas is contacted with a molten salt, impurities such as aluminum, iron, and titanium are removed and the resulting product is considered fused-salt scrubbed. Zirconium and hafnium are sold to a purity specification. Generally speaking, normal production without scrubbing is capable of meeting specifications. There are, however, several considerations That make the knowledge of methods of additional purification highly desirable. These are: 1) the control of product analysis; 2) the production of a pure product for special applications; 3) the salvaging of off-specification material; and 4) the use of raw materials with higher impurity levels than 1 he present raw materials. You will note that items 1 and 2 are somewhat complementary to each other and that item 4 assumes that The present process has impurity removal limitations. To better understand the part that fused-salt scrubbing of zirconium tetrachloride plays in the manufacture of zirconium, Fig. 1 contains an illustrated flow sheet of the industrial production of zirconium metal. In referring to Fig. 1, we can point out the specific benefits derived from our ability to purify zirconium tetrachloride. Purification of the crude (hafnium-containing) zirconium

Jan 1, 1962

By M J. Saynor, J B. C Lowry

The Ranger Uranium Mine is located in the wet-dry monsoonal tropics approximately 250 km east of Darwin in the Northern Territory of Australia (Figure 1). Mining of open-cut ore bodies commenced in 1980 (Pit 1) and ceased in 2012 (Pit 3) and milling and production are scheduled to cease by 2021. At the conclusion of mining and milling operations, mine tailings will be returned to the mined out pits 1 and 3, which must then be physically isolated from the environment for at least 10,000 years (Australian Government 1999). The final landform also needs to have sufficient mitigation measures in place to ensure that areas downstream are not impacted by erosion products from the mine site. The proposed post-mining rehabilitated landform will cover approximately 847 hectares (8.5 km2) which represents an area that has the potential to supply sediment to catchments and streams downstream. One method of reducing runoff and associated sediment is the construction of rip lines along the contour to slow down the runoff velocity and to also trap fine sediment and nutrients in the depressions to assist vegetation growth.CITATION:Saynor, M J and Lowry, J B C, 2018. The impact of rip lines on erosion at the Ranger Mine Site, in Proceedings Life-of-Mine 2018, pp 150–154 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By A Lance McAnuff, Andrew Curic

Until relatively recently, underwater blasting operations for channel deepening, dock construction and pipeline crossings of lakes, rivers and streams were conducted without much regard for the potential side-effects on aquatic organisms.

Jan 1, 1997

By Ernest Gayford

This is a nontechnical paper on flotation, subdivided under three general headings: (I) Definition of flotation; (2) what flotation is now doing in Utah; and (3) what is the future of flotation? Definition T. A. Rickard defines flotation' as "the act or state of floating," from the French flottaison, water-line and flotter, to float. The dictionary defines flotation as "the science of floating bodies." The flotation process is a method of concentrating ores by frothing. Weinig and Palmer,2 define flotation as follows: What is the flotation process? Briefly, it consists in the agitation of finely divided ore in water containing bubbles of air or gas, a small amount of oil and, usually, other reagents, soluble and insoluble; under these conditions the small particles of native metals, sulfides, arsenides, antimonides, selenides and tellurides show a tendency to attach themselves to the films of the bubbles, and are thus carried to the surface of the water. The oxidized gangue minerals, such as quartz, feldspar, limestone, hematite, etc., show much less affinity for the bubbles, are easily wetted by the water, and either remain in suspension in the water, or sink to the bottom of the vessel. If the bubbles are sufficiently stable they can be removed, carrying their load of sulfide-mineral particles with them. Thus there can be effected a separation of the two classes of minerals from each other, assuming that the grinding has been sufficient to unlock all of the particles of different composition. The separation does not depend upon differences in specific gravity of the various minerals; in fact, the sulfides are usually heavier than the oxides, and some of the heaviest sulfide minerals are the easiest to float. A particle of mineral may be so large, however, that its weight will counteract its affinity for the film of the bubble. In most cases the ore must be fine enough to pass a screen having at least 48 meshes to the linear inch. Taggart3 defines flotation as follows: Flotation is a method of wet concentration of ores in which separation of mineral from gangue is effected by causing the mineral to float at or above the surface of a body of liquid pulp while the gangue becomes or remains submerged. The method

Jan 1, 1928

By G. Vibert Douglas

NICKEL minerals are known in New Brunswick but have never been reported from Nova Scotia. The attention of the writers was drawn to an occurrence of pyrrhotite, reported to carry nickel, at the Second Gold brook, Middle river, Cape Breton. The purpose of this paper is to record the occurrence and give an account of the general geological association. In a later paper it may be possible to give greater details? than are available at present. GEOLOGY The area lies at the edge of a plateau of Precambrian rocks which forms the panhandle of Cape Breton island. This plateau has a general elevation of 1,200 feet. Middle river, with its tributaries, the First, Second, and Third Gold brooks drains the area. The lower country to east and southeast of the plateau is underlain by lower Carboniferous sediments. The rocks of the plateau are presumably of Precambrian age but have never been definitely correlated with the Gold-Bearing Series of the mainland. ?There i:s; however, some resemblance, although they have apparently been more intensely mountain-built. They are essentially fine grained, sheared quartzites and slates . The general strike is east and west, with a north dip of 45° to 55°. There are smalllocal drag-folds in the area. The only igneous rock in the immediate vicinity is an intrusive pink porphyry. It has small phenocrysts of quartz and feldspar. It has intruded the sediments generally along the structural planes, but in places crosses the structure . Its intrusive character is further proved by the fact that it contains xenoliths of the quartzite.

Jan 1, 1937