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Mining is a fundamental activity on which modern society and the world's economy are entirely dependent. Mining investors, large and small, invest on an international scale, frequently being active in several countries.   Prior to committing investment to new countries, the prudent investor will consider the risk involved by analysing a number of physical, financial, administrative and political parameters that impact on the potential financial returns it is seeking. This paper considers these risk factors in relationship to New Zealand and six competitor countries. The conclusion is that for reasons largely within the control of our politicians, New Zealand is a high risk country for mining investors.

Jan 1, 1993

By D. Hoffmann, S. Plumb

IRUP is an iron-rich ultramafic pegmatite rock that formed due to hot ironrich fluids and gases replacing local stratigraphic zones of the Bushveld Complex. This study focuses on the estimation of the probability of IRUP occurrence on the Merensky Reef at the Marikana Karee Mine. A 2.15 million centare IRUP-rich domain at the Karee Mine was initially defined from the interpretation of a surface aeromagnetic anomaly, and exposures in the mine workings. Surface boreholes (spaced 250-500 m apart) within this IRUP domain contain approximately equal numbers of IRUP-replaced and IRUP-free intersections. Owing to the uncertainty in the continuity of the IRUP alteration (a result of the wide borehole spacing), the risk associated with the development of mining infrastructure within this domain is unquantifiable. Semi-quantitative data comprising visual estimates of IRUP replacement from reef development mapping data and surface borehole reef intersections was interpolated into blocks using indicator kriging estimation. Comparative analyses of the estimate of IRUP occurrences were made by changing the block size and declustering the data systematically. Reconciliations of the probability of IRUP predicted from the block models derived from the different data-sets and sequential indicator simulation models were analysed for four mining study blocks. A quantitative approach to modelling the occurrence of IRUP can be an additional tool for refining the estimate of the geological losses that inform the mine plan in such high-risk zones.

Jan 1, 2015

U.S. Minerals Coordinating Council Advised. -The Critical Materials Act of 1981, H. R. 4281, introduced on July 27, would create a Council on Critical Materials in the White House Executive Office to oversee Federal materials programs involving $1 billion committed to research by 14 agencies, and to serve as the President's focal point to evaluate materials policy. It was introduced by Congressman Fuqua (D-Fla.) whose Committee on Science and Technology has over-sight over the implementation of P. L. 96-479, the National Materials and Minerals Policy, Research and Development Act of 1980. Bulgaria's Mineral Bank. -Recently Bulgaria established a mineral bank to facilitate receipt of foreign credits for exploiting Bulgaria's mineral raw materials. The bank has wide powers to enter into business arrangements with foreign creditors. Bulgaria's main interest in trading with the West is to import the technology for developing energy and mineral resources.

Jan 1, 1981

By Marcio José Campos Borba

A cotação do minério de ferro caiu muito nos últimos anos. Em função disto, a Vale buscou se adaptar para continuar atendendo às condições do mercado. Considerando que o principal cliente mundial atualmente é a China, que os principais concorrentes estão na Austrália, e que as suas operações deste produto estão localizadas no Brasil, os desafios da Vale têm sido cada vez maiores para se produzir com qualidade e com baixo custo. Com este cenário, o desdobramento da estratégia da empresa, bem como sua execução, têm merecido destaque especial na Diretoria de Ferrosos Sudeste. Em meio a este momento, foi implantado o Escritório de Projetos, que recebeu a responsabilidade pela condução do planejamento estratégico, desdobramento da estratégia e gestão de carteira de projetos nessa Diretoria, de forma integrada com outros pilares da Gestão da Qualidade.

Oct 30, 2017

The paper is a general review of practice in design of sub-level open stopes in Northern Rhodesian copper mines and gives examples of some interesting developments during the last five or six years. It discusses the effect of hangingwall subsidence and the methods used to combat rock pressure on working areas.INTRODUCTIONAll producing mines on the Northern Rhodesian Copperbelt have large ore reserves and are designed for high rates of production. The three mines (Mufulira, Rhokana Corporation, and Roan Antelope) where sub-level open stoping is used, hoist from 250,000 to over 400,000 short tons of ore a month so that any stoping method used must be adaptable to concentrated' mining. Individqal stopes produce from 5,000 to over 25,000 short tons of ore a month.Structure af the ore bearing sediments is simple; faulting in ore is almost entirely absent and copper mineralisation is found in the same beds over great distances...

Jan 1, 1954

By S. C. Richardson

The electrowinning (EW) circuit involves using DC current in the electro-deposition of metal ions dissolved in an electrolyte solution. This paper reviews a method to generate an electrical model of an EW circuit and the resulting DC current flow and voltage distribution within the circuit. Topics include: calculations of electrolyte conductivity and the equivalent electrical resistance of the electrolyte within the electrolyte pipelines connected to the EW circuit; the breakdown and classification of the EW cell voltage into thermodynamic and ohmic potentials; methods to calculate current flow and voltage distribution throughout the EW circuit; and the development of an interactive visual computer model to simulate an actual EW circuit. Stray current can pose an electrical shock hazard to employees in electrolytic tankhouses. Increased awareness and understanding of the voltage distribution and potential stray current in an EW circuit can help mitigate the risk of tankhouse workers becoming exposed to electrical shock hazards. INTRODUCTION Copper electrowinning tankhouses include rectifiers that deliver large amount of DC current to a series of electrolytic cells consisting of electrolyte solution and electrode pairs. The design also includes metallic conductors in the circuit which include the rectifier’s positive and negative busbar, inter-cell busbar, and the anode and cathode frames. The electrolyte acts as an electrical conductor that transfers current via ions between the anodic and cathodic electrodes within the cell. Electrolyte, as a conductor, is also capable of conducting DC current outside the main EW circuit through the connected electrolyte feed and return pipe systems. DC current that follows a path other than the intended path through the series of electrolytic cells is referred to as “stray current”. Developing an electrical model enhances understanding of voltage distribution and current flow in an EW circuit. This paper discusses the derivation of the various representative components of the model as well as the output from the model. An interactive visual computer simulation incorporates the model output in order to aid in the understanding of voltage distribution and current flow throughout the EW circuit.

Jan 1, 2019

G. A. Burr, Parral, Chihuahua, Mexico (communication to the Secretaryt): I regret that Mr. Norris did not give more attention to the hoisting of water in inclined shafts or slopes: the only slope mentioned being Hickory Ridge Slope, No. 4, of the Union Coal Co. The surface arrangement, illustrated in Fig. 12 of his paper, if not unpractical, is at least unscientific and cumbersome. It is my opinion that the back- and sideguides shown in Fig. 12 are not only unnecessary where rails are used as a track, but are unsafe, excepting in the case of a very firm hanging-wall, or roof, and sides of vein-matter, having absolutely no tendency, either to settle from the back, or to squeeze from the sides, an effect which would inevitably force the guides out of alignment. The accompanying illustration, Fig. 1, shows what I consider a better method of hoisting water than that described by Mr. Norris. This method is based on the general practice in metalliferous mines of the West, where skips are used in slopes; and, while it is not original with me, I have frequently used it with very satisfactory results for dumping both ore and water.

Jan 1, 1904

By Victor V. Damiano

THOMPSON1 proposed a very convenient nomenclature in which an imaginary regular tetrahedron was used to facilitate the analysis of dislocation interactions in fcc materials. The faces of the tetrahedron were constructed parallel to four different sets of (111) planes, and the six edges of the tetrahedron then represented the six 1/2 [110] Burgers vectors. The lines which joined the midpoint of a tetrahedron face with the ends of one of its edges represented the Burgers vectors of the partial dislocations into which the six 1/2 [I101 Burgers vectors dissociate. Using Frank&apos;s2 notation, all of the dislocations and their partial dislocations were identified and numerous possible interactions were postulated. The case of hexagonal crystals is unfortunately more complex, but it appears convenient to introduce a system similar to that of Thompson1 to describe the various slip planes and Burgers vectors encountered in cph structures. The system proposed has limited application but serves to identify the following slip systems {0001} <l20>, {1010} <1120>,

Jan 1, 1963

By G Tripp, G Lorusso

The Velvet gold orebody (153 Koz Au) is located near the Kanowna Belle gold deposit in the Boorara Domain of the Kalgoorlie Terrane, a subdivision of the Archaean Eastern Goldfields Superterrane (Swager et al, 1990). Gold mineralisation at Velvet is hosted within an intrusion of intermediate composition that broadly follows a sub vertical hanging wall splay of the Fitzroy Shear Zone.Velvet was discovered in 2003 during an underground exploration drilling program targeting potential strike extensions to the Kanowna Belle deposit. Diamond drill hole KDU1595 returned a downhole intercept of 36 m grading 4.6 ppm Au approximately 500 m west of the deposit and at a vertical depth of 700 m below surface in the immediate hanging wall of the primary Kanowna Belle host structure, the Fitzroy Shear Zone. Subsequent drilling completed following the initial discovery, from both surface and underground collar positions, failed to replicate this result.In 2014, KDU1595 was resurveyed gyroscopically and the mineralised intercept correctly located. Additional drilling was undertaken to follow-up the repositioned discovery hole. Challenges included poor drilling angles through the Fitzroy Shear Zone, excessive deviation during drilling and the unknown geometry of the target. Navigational drilling helped to successfully penetrate the Fitzroy Shear Zone and in April 2015, drill hole KDU3234 returned a significant downhole intercept of 45 m grading 5.6 ppm Au.Additional drilling success resulted in a decision to develop a 600 m drive to serve as a dual-purpose access for further exploration and mining. This was a potential risk considering that the orebody geometry was unknown and all significant drilling results were clustered within a 50 m &#215; 50 m panel. Development commenced in June 2015 and the first ore cut taken in April 2016. Geological mapping and structural interpretation, together with multi-element and spectral analysis of drill samples has enabled several other target areas to be identified for exploration. The Velvet mining area is critical to continued production at Kanowna Belle. Geological understanding must advance as mining progresses to ensure continued resource growth and optimal extraction of reserves.CITATION:Lorusso, G, Rogers, J and Tripp, G, 2017. Velvet underground exhumed – discovery and development of a new mining front at the Kanowna Belle gold mine, in Proceedings Tenth International Mining Geology Conference 2017, pp 169–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By H. L. Anthony, A. C. Richardson, G. D. Coe

"INTRODUCTION The Warrior View mine of the Seaboard Coal Corporation is located in Tuscaloosa County on the Warrior River about 14 miles northeast of Tuscaloosa, Ala. The Brookwood bed at this point yields a coal with fair coking qualities, and the product from neighboring mines on this bed has been used for the manufacture of blast furnace coke. The output of the Warrior View mine, however, is used exclusively for domestic and steam-raising purposes.This paper continues the series° of reports on the washability of Alabama coals which are based upon the study of coal preparation in Alabama now being conducted by the U. S. Bureau of Mines and the University of Alabama with the cooperation of the different coal mining companies. This paper contains screen-sizing and float-and-sink tests of a representative sample of run-of-mine coal, and flakiness and crushing tests on certain sizes.Published information on the Brookwood bed is very meager. Fieldner6 gives the proximate and ultimate analyses for a number of seam samples taken from representative mines working this bed. Gandrud and Britton7 show sections of this bed taken at Searles, Ala. They also give the specific gravities of the coal, the bone, and the shale partings.Table 1 give the proximate and ultimate analyses for the 3/4 to 3/16 inch size of raw coal. Table 2 gives the sulphur content and the ash fusibility temperatures of the float-and-sink fractions for this same size. The character of the coal is very uniform throughout the range of sizes produced and, as it was not convenient to have these analyses on all sizes, this size was chosen as being representative of the coal. From the information available it is evident that the coal preparation problem is restricted to one of ash reduction.SAMPLING AT THE MINEAt the Warrior View mine the run-of-mine coal is dumped from the mine cars upon a 3-inch grizzly. The oversize is crushed in rolls set at 24 inches and joins the undersize before being elevated to the raw-coal bin ahead of the jig. The sample was caught at the point where elevates discharges into the raw-coal bin, by taking a proportional amount of the coal at 10-minute intervals over the period of a day's run, The total sample amounting to 2.7 tons was shipped to the laboratory at Tuscaloosa for the washability studies."

May 1, 1932

By R. A. Beall

Homogeneous zirconium-alloy ingots have been cast on a production basis by the consumable-electrode arc-melting process at the Northwest Electrodevelopment Experiment Station, Bureau of Mines, Albany, Oreg. This paper describes the various methods used to introduce alloying materials into the ingot and evaluates 1 each method by the degree of homogeneity of resulting ingots, as determined in tests on sections cut from the ingots. As many as 30 or more ingots, each 6 to 10 inches in diameter and weighing 300 to 500 pounds, were melted, using each method; and, as most of them subsequently were fabricated to strip 0.1 inch thick, the test results are considered to be representative of production practice. Ingot homogeneity has been considered more difficult to achieve in arc-melting practice than by methods where the molten metal is poured into molds and the addition can be stirred into the total mass of metal before casting. Owing to the unique requirements of consumable-electrode arc melting the addition can be made only to that part of the total mass of the ingot that is molten at one time. Observation of the flowlines in 500-pound ingots produced at Albany indicates that the molten pool has a maximum depth about equal to the ingot diameter. The weight of metal molten at one time is, therefore, not over 100 pounds. Characteristically, the arc-melting process is conducive to segregation, which can be overcome, at least partly, by adding the alloy constituents almost continuously during casting.

Jan 1, 1956

By Jacob Masliyah, Zhiang Zhou, Dharamdat Christendat, Tshitende Kasongo, Kevin Hyland, Zhenghe Xu, Ted Kizior, Douglas Cox

"A novel on-line visualization system, previously developed at Syncrude Canada Ltd., has been modified to characterize rising bubbles, particles and particle-bubble aggregates in a flotation process. With this system, the bubble size and rise velocity in a laboratory flotation cell can be determined. The technique allows the loading of solids on bubbles to be visualized, thereby providing an in-depth understanding of sub-processes of flotation. A step-by-step data processing procedure is presented. The applicability of the developed system to mineral flotation and bitumen extraction is discussed. Under batch flotation conditions in a laboratory Denver cell, three main bubble-particle attachment patterns are observed. They are: i) single particles attached to single bubbles, ii) particle aggregates loaded on single bubbles; and iii) a group of particles aggregated with a group of bubbles. The results demonstrate that the on-line visualization system is a powerful tool for understanding and diagnosing flotation processes.INTRODUCTIONAir (Gas) bubbles are an indispensable component in a flotation system. Both industrial practice and theoretical analysis indicate (Yoon, 1993; Diaz-penafiel and Dobby, 1994) that the size and population of bubbles are two important process parameters in modeling flotation. More recent investigations (Finch, et al., 1999; Gorain, et al., 1997) suggest that for a given flotation system, bubble surface area flux, defined as the air liquid interfacial area per unit time and unit cross-sectional area of flotation cell, showed a better correlation with the flotation rate constant. As a result, the bubble surface area flux is now being considered as a key parameter to account for the combined effect of bubble size and population in evaluating the performance of flotation machines and modeling flotation processes. However, the success of using bubble surface area flux in flotation process modeling largely depends on how accurate it can be determined or estimated (Finch, et al., 1999)."

Jan 1, 2000

By G. C. Sun

Rock mechanics properties, i.e. uniaxial and triaxial compressive strength, indirect tensile strength shear strength, Young&apos;s modulus, and poisson&apos;s ratio were collected for coal and related strata from 50 coal seams in 90 mines. The methodology of data organization and retrieval is described in details. The values and .ranges of those properties are also discussed.

Jan 1, 1993

By F. W. Newhall

DURING the latter part of the year 1931, the Republic mine of the Republic Steel Corporation, at Republic, about 4 miles south of Browns-ville, Pa., was mining coal along four rib or fracture lines. One of these lines, the west butt rib line, was retreating towards a concrete-lined air shaft, 320 ft. deep, which had been sunk in 1911 for ventilation purposes. With the normal rate of mining at that time, it was expected that this rib line would pass the shaft in three or four months and the shaft would then be abandoned and allowed to cave. Realizing the opportunity presented for the study of an unusual case of ground movement, the question of conducting the study was presented by the junior author to the chairman of the Institute&apos;s committee on Ground Movement and Subsidence, Mr. George S. Rice, who presented the matter to Mr. G. H. Morse, General Manager of the Northern Mines, Republic Steel Corpora-tion, and he agreed to cooperate with the Bureau of Mines in making the study, the results of which are presented in this paper. Acknowledg-ments are due to Mr. Morse for his full cooperation in this work and to Mr. G. S. Rice and Mr. J. W. Paul, both of the U. S. Bureau of Mines, for their advice and guidance during the course of the work. The authors are indebted to Mr. B. F. Herbert, mining engineer, Northern Coal Mines, Republic Steel Corporation, who assisted in all the surveys, and Mr. W. H. Smith, draftsman, U. S. Bureau of Mines, who prepared all illustrations for publication.

Jan 1, 1934

By Marcella Mateus de Mello

O presente trabalho objetiva analisar a influência da distribuição de intensidade espacial do laser na geração de padrões de speckle em superfícies metálicas. Os padrões de speckle estudados são obtidos quando o laser atinge uma superfície metálica. A análise da imagem de padrões de speckle pode ser relacionada com a rugosidade de superfícies metálicas iluminadas com o laser. Com esse estudo pretendemos melhorar a sensibilidade das medidas de rugosidade de superfícies metálicas a partir das imagens de padrões de speckle.

Aug 17, 2017

By Sylvain Létourneau

Help organizations maximize the benefits of the data that they collect ? perform scientific research in: machine learning, data mining, statistics, artificial intelligence, soft computing, information retrieval, information systems, and natural language processing ? preferred application areas: Equipment Health Management, Bioinformatics, Health, Web Mining ? today?s talk limited to Equipment Health Management While the aircraft is still in the air, IDS: ? clusters relevant WRN, FLR, and snag (pilot) messages ? identifies probable causes based on TSM and provide links to corresponding TSM pages ? assesses MEL conditions (GO, NOGO, GOIF, ?) ? displays relevant maintenance history, suggests fixes based on similar cases ? Commercialization with MxI Technologies Ltd and Air Canada in 2000

May 1, 2008

By Roy H. Poston

This paper sets forth the mode of ore occurrence, characteristics of ore and country rocks, methods of exploration, development, and. ore extraction, and the costs of underground operation at No. 8 mine of the St. Louis Smelting and Refining Works of the National Lead Co. located near the southern extremity of the Southeast Missouri lead district. The author acknowledges the assistance of E. T. Campbell, geologist, in the preparation of the paragraphs on the geology of the ores. HISTORY The first record of mining in St. Francois County, Mo., concerns more or less shallow semisurface "diggings" which were worked about the year 174-2. In 1864, however, the discovery of the disseminated deposits, the present source of lead, was made on property near the town of Bone Terre. Winslow has estimated the lead-ore production in this county prior to 1869 to be 59,526 tons.3

Jan 1, 1929

By Andre Luis de Zorzi Marin

O corte a plasma de aço inoxidável tem história relativamente nova em comparação com outros meios de corte de metais. Frequentemente os usuários de corte plasma se deparam com questões específicas ao corte do aço inoxidável, como qualidade de corte, velocidade de corte, custo operacional e alterações nas propriedades metalúrgicas. Nos últimos vinte anos as tecnologias aplicadas no corte plasma do aço inoxidável tem evoluído com resultados atrativos nos últimos cinco anos. Estas tecnologias versam com alterações na mistura dos gases de plasma e de proteção, ou ainda, na mudança dos bicos de corte plasma buscando melhor constrição do arco plasma, e a devida seleção de gases em função da espessura de corte. Este trabalho foi desenvolvido através de revisão bibliográfica das principais tecnologias apresentadas pela indústria nas últimas duas décadas para o corte de aço inoxidável com plasma, e testes laboratoriais de corte com as últimas tecnologias de corte. Entre os resultados estão a redução até a eliminação da escória pós-corte, uma borda de corte menos arredondada, melhora na coloração da superfície e diminuição da zona afetada pelo calor na peça de trabalho. A importância do trabalho se dá pelo aumento da participação do uso do aço inoxidável dada a sua importância para a economia, em especial nos setores de energia, processamento de alimentos, papel e celulose e transportes que necessitam de melhorias no corte deste metal e suas ligas.

Jan 16, 2018

The reduction of zinc from slags by a molten, carbon-saturated bath was examined in a laboratory study under conditions of continuous slag feeding. The results show that it is possible to reduce the bulk of the zinc from the slag before there is a net reduction of iron. However, the recovery of zinc was not as high as in batch tests performed in an earlier study. Lead in the slag was reduced simultaneously with the zinc to very low levels and was volatilised. Copper in the slag was reduced and dissolved in the alloy. An attempt was made to identify potentially commercial ways of treating zinc slags using an iron bath. The approaches that appear to have the greatest potential are reduction in a batch process using electrical heating and reduction in a continuous process with co- or countercurrent flow of the slag and alloy. In the latter the alloy would be prepared in a separate furnace before being contacted with the slag. The purpose of this would be to superheat and carburise the alloy so that no additional heat or reductant would have to be supplied in the slag-alloy reactor

Jul 1, 1991

Coal Division Industrial Minerals Division Minerals Beneficiation Division Mining, Geology and Geophysics Division OFFICERS AND COMMITTEES S D Michaelson, President J W Woomer, President-elect Elmer A Jones, Past President C E Lawall, Eastern Regional Vice-President G Donald Emigh, Central Regional Vice-President J D Forrester, Western Regional Vice-president R B Ladoo, Treasurer John Cameron Fox, Secretary

Jan 1, 1958