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By R. E. Cuthbertson

AN early appreciation by the management that Climax ore presented a challenging problem of economic concentration was responsible for the establishment, in June 1926, of an ore-testing department at the experimental plant of the Colorado School of Mines at Golden, some ninety miles from Climax. An engineering office was later organized in the same community for the design of all ore-treatment units erected at Climax during the period of rapid growth. Work of the ore-testing and design staffs was effectively co-ordinated under a common head. The primary reason for having the ore-testing and plant design departments in Golden, was to place these activities under the able supervision of A. J. Weinig, consultant for the Climax Molybdenum Co., and director of the experimental plant. A secondary consideration was the availability of excellent facilities for research in ore dressing in a highly favorable environment. Concentration of molybdenite by flotation from an ore of simple mineral composition does not appear, superficially, to present a serious problem in ore dressing but experience belies this apparent simplicity. The molybdenite content of average Climax ore is low and it is finely

Jan 1, 1946

By Rhys Baker, Tim O’Brien, Joshua M. Hoffman

This paper discusses this division of power as it relates to the explosives industry. Each branch is responsive to the public and the processes through which each promulgates regulation and legislation require public input in different forms.

Feb 1, 2020

By Jochen Maurer, Dr. Christian Hoyme, Dr. Hans Regler

Currently, it is very difficult to obtain qualitative and quantitative information about the status and production process of a construction site. As a rule, companies depend on reports from on-site experts. There is no end-to-end digitalization due to the mobility of equipment and ever-changing locations. Equipment from different manufacturers, especially in special foundation engineering, is highly specialized. Any data collected by this equipment is recorded in proprietary formats and made available on the manufacturers' platforms. This exacerbates the situation, making simple analysis of performance indicators impossible. Most functions such as construction diaries, equipment utilization analyses, etc. are implemented only as standalone solutions. This does not allow for prompt visualization and intervention in critical process sequences because the construction site process is usually managed using a cost-based method. Furthermore, special foundation engineering requires a high level of expertise in an extremely wide range of construction processes. In this article, the results from a set of non-proprietary performance analysis tools are presented using numerous practical examples. Once a construction element is completed, the equipment data is immediately transferred to the platform using the latest cloud technology. Because the data is normalized, construction progress can be documented immediately, even for mixed equipment fleets. Bottlenecks can be immediately detected by visualizing the current performance of the production process, which is broken down into individual steps. Modern analyses of this equipment data improve quality, thereby providing better information about current performance. These sets of tools are essential for changing from the current monetary or cost-based method of process management to time- and bottleneck-oriented management. This makes it much easier to identify the critical path during projects. The article shows that processes can be documented and managed.

By Lorena Cristina Amorim Moura

O balanço de enxofre ao longo da cadeia de produção de aço é um problema muito discutido no setor siderúrgico, pois afeta a qualidade do produto final. Assim, este estudo tem como objetivo desenvolver uma metodologia de previsão de enxofre do coque, a partir de enxofre do carvão, com base na sua taxa de dessulfuração, obtida através do Índice de Inchamento Livre (FSI) em escala laboratorial. Estes resultados mostram boa correlação com o processo de fabricação de coque, permitindo a determinação do valor em uso em relação ao teor de S de cada carvão.

Oct 30, 2017

By Marcos Paulo Kohler Caldas

O desenvolvendo da indústria de eletroeletrônicos associada ao barateamento dos produtos tem reduzido a vida útil de equipamentos levando a uma geração elevada de resíduos de equipamentos eletroeletrônicos (REEE). Um componente desse resíduo são as placas de circuito impresso, que possuem em sua composição altos teores de metais, que podem ser recuperados através de processos de reciclagem. O presente trabalho busca caracterizar placas mãe de computador, determinando sua quantidade de material orgânico, cerâmico e metálico. As placas foram direcionadas para cominuição, que foi realizada em moinho de facas com grelha de 9mm, seguida por um moinho de martelos, atingindo uma granulometria menor que 2mm. A amostra foi então quarteada, para uma maior homogeneização e passou por ensaio de digestão em água régia. O licor resultante foi diluído para determinação do teor dos metais Ag, Al, Au, Ba, Ca, Cu, Fe, Ni, Pb, Sn, e Zn utilizando espectrometria de emissão óptica por indução de plasma (ICP-OES). O sólido filtrado, também resultante da digestão em água régia, passou por um ensaio de perda ao fogo a 800°C por uma hora, para determinar o teor de material orgânico. Os resultados indicaram que o Cu é o metal de maior concentração com 22,5% na placa de circuito impresso e que a mesma possui 43,7% de metais, 31,9% de polímeros e 24,4% de cerâmicas. A prata representa 0,04% dos metais e sua obtenção será realizada na forma de nanopartículas a partir de rotas hidrometalúrgicas.

Aug 8, 2018

By Robert A. Brown

"The O'Brien mine is in the west-central part of Cadillac township along the Cadillac 'break', which extends for 7,500 feet from west to east across the property.The ground was staked in 1924 by A. Dumont and W. Hermeston, prospecting for M. J. O'Brien, Limited. The first vein discovered is that now known as No. 1. The No. 4 vein was later exposed on the surface; the other veins known to be present were revealed by underground work and diamond drilling carried out both from the surface and underground.The mine is developed from three vertical shafts: No .. 2 extending from the surface to 2,000 feet; No. 3 from the surface to 1,500 feet; and No. 4 from 2,000 to 3,000 feet. There is on the property a mill of about 200 tons a day capacity, the usual shops, and a townsite housing about forty-five families. Gold production to the end of September, 1944, amounted to 295,824 fine oz. from ore having an average grade of 0.505 oz. a ton. In addition, the mill recovered 3,237 tons of arsenic trioxide having a purity of 83 per cent As2O3.GENERAL GEOLOGYThe four main groups of rocks of the Cadillac area- the Cadillac, Blake River, Kewagama or Pontiac, and Malartic- are found within the boundaries of the property. However, as these rocks have been fully described in · various government reports (1,2,3,4,5,6) and all the known orebodies occur within one group- the Blake River-a detailed description of the geology will be dispensed with here. The known ore deposits lie south of the Cadillac 'break' in a group of rocks that includes 'greenstones', greywackes, conglomerate, porphyries, and a rock of gabbroic composition that may be intrusive. Both flows and tuffs can be recognized in the 'greenstones'. The two bands of porphyry that trend easterly across most of the property have been considered by some observers to be dyke rocks and by others to be flows. Certain evidence points to their being dykes that were intruded as sills considerably prior to the emplacement of the gold-bearing veins, but the possibility of flow origin cannot be fully rejected. North of the talc-chlorite-carbonate schist zone forming the 'break' the rocks are conglomerate and greywacke with iron formation, in which there are no known veins of ore grade. Within the schist zone are minor acid and basic intrusives. The general trend of both bedding and schistosity is a few degrees south of east. The dip is generally vertica1 or steep to the south."

Jan 1, 1954

By Corale L. Brierley

Bacteria, algae and fungi react to heavy metals in their environment by immobilizing, mobilizing and/or transforming metals. Microorganisms carry out these changes by (1) precipitating metals outside of the microbial cell, (2) binding and complexing metals to the outside of the microbial cell's protective coating, (3) accumulating metals inside of the microbial cell, or (4) transforming metals by oxidation, reduction, methylation or demethylation. Most of these mechanisms are operative in constructed aerobic and anaerobic wetlands for metal's remediation. Several more advanced biotechnologies for metal's removal from aqueous streams have been introduced, but have not been widely accepted commercially.

Jan 1, 1995

By C. Chamberlain

The Telfer Project, Australia's newest, largest, and most remote gold mine treats 480 kt of ore grading 9.33 g/t derived from open pit mining operations. Coarse gold is recovered by gravity concentration with jigs and further upgraded wing a continuous strake launder table, and by amalgamation. Remaining gold is recovered in a cyanide circuit and incorporates flat bottom air agitators, counter current decantation (CCD) and stellar filters for clarification and precipitate removal. Overall recovery into a bullion averages 98%. The mill incorporates a number of design features that allow for maximum efficiency and security wing a minimum number of operation personnel.

Jan 1, 1983

By Daniel Richards, Dr Rob Farnfield, Dr Geoff Adderley

The 8-millisecond rule has been in use for many years as a basic technique to help minimize vibration levels from surface blasting operations. The rule was based on work carried out in the 1960’s by the USBM by recording the vibration levels from a series of test blasts in a quarry over a range of distances. This work included the firing of a series of single hole blasts and a number of single row production blasts using a variety of inter-hole delay times. The delay times employed were limited by the technology available at that time to instantaneous, 9, 17 and 34 milliseconds. There have been several papers in recent years suggesting that the use of the 8-millisecond rule is no longer required, when using electronic detonators, due to their enhanced accuracy and greater initiation pattern design flexibility. This paper examines this proposition by revisiting the original work and employing the linear superposition technique to reprocess some of the original recordings. Similar techniques are then applied to a large database of single hole vibration recordings for a range of rock types, distances, and number of decks, with calculated reinforcements compared to the minimum separations in typical patterns. The results suggest that there is some validity to the 8-millisecond rule when applied to electronic detonators but not in the way it is traditionally applied. Simple guidance is suggested for those designing blasts with electronic detonators to minimize vibration levels even if the benefits of linear superposition trials are not available.

Jan 21, 2025

By Tiruvengala Padma, Nilesh Naik

Piles are common type of deep foundation elements used for the special bridges, transmission towers, Jetties, and tall structures. Lateral loads on the structures can be due to either earth pressures, wind, waves, impact, moving vehicles and eccentric application of axial loads or in combination of the loads. Hence the lateral capacity of piles plays a major role in determining the pile dimensions. The laterally loaded pile analysis is a soil-structure interaction problem as the lateral capacity of pile depends on the soil strength and stiffness parameters and its reaction to the lateral load on pile. The common approach to determine the lateral load analysis of piles is the Beam on Lateral Springs Method also known as “p-y” method. In this method the pile is modelled as a beam and supporting soil is modelled as lateral springs. This study is focused on the comparison of output obtained from three geotechnical softwares namely FB-MultiPier, L- Pile and Wallap. L-Pile Software is based on Finite Difference Method, Wallap on Horizontal Subgrade Modulus Method and FB MultiPier on Finite Element Method. Pile response in terms of deflection, shear force and bending moments under vertical and horizontal loads from above three software are compared and concluded.

Sep 1, 2022

By Y K. Leong

Occasionally additives are used in the wet processing of iron ore tailings and slurries, for examples, in the thickening of tailings with flocculant to recover process water, and in the smooth pumping of concentrated slurries. They can mitigate slurry behavioural issues that could significantly affect the plant operation and production. The nature of iron ore business requiring the plant to have a high throughput to be economical, large amounts of slurries are therefore processed every day. The quantity of additives needed will correspondingly be large and so are the associated costs. This could have a significant impact on the plant profitability. If additives are used they must be very costeffective. NaOH is among the lowest cost chemicals available, at ~US$400 per ton. In this paper we will look at use of composite additives involving phosphate compounds with NaOH added to reduce the cost, for the control of iron ore slurries rheology. The NaOH worked synergistically with the phosphate compounds. The effectiveness of these composite additives in viscosity reduction can be neutralised by another cheap additive such as lime or a Ca(II)-based salt turning the slurries back to being a paste. Tailings paste is an ideal material for safe storage in the dam. These composite additives can also be used to facilitate the recovery of iron ore at commercial grade from tailings (Leong, 2020a, 2021a).

Sep 18, 2023

By Ch. R. V. S. Nagesh, Ramesh Naidu Mandapati, Venkata Swamy Nalajala, Tondepu Subbaiah, Naga Jyothi Kothamasu

Leaching studies of magnesite obtained from Tamilnadu Magnesite Limited, Salem, have been carried out using hydrochloric acid leaching and percentage of magnesium chloride recovered was estimated. The variables considered in this study were the following: duration of leaching, volume percentage of hydrochloric acid, temperature, and pulp density. Percentage recovery of magnesium chloride increased with duration of the leaching, volume % of concentrated hydrochloric acid, and temperature. Percentage recovery of magnesium chloride decreased with increase of pulp density. The optimum conditions found to be pulp density (10%), hydrochloric acid concentration (30%), duration of leaching (2 h), and temperature (348.15 K). Iron was removed by treating the leach liquor with hydrogen peroxide and by raising the pH to 3.5–4. The purified leach liquor was subjected to spray drying for producing high pure magnesium chloride.

Jun 7, 2022

By N J Welham

A commercial enargite concentrate was mechanically milled in inert and oxidising atmospheres for 10 hours. No substantial effect was observed in either an inert atmosphere or in air other than a broadening and weakening of the diffraction peaks. Milling dry in oxygen or wet in air was dramatic with a significant reaction occurring which formed arsenolite, As2O3 and CuSO4.5H2O, both of which are readily soluble.A small amount of SO2 was also formed. Dissolution in acid left CuS as the major phase implying incomplete oxidation. The small fraction of tennantite in the sample was comparatively resistant to oxidation.

Jan 1, 2001

By A. D. Garman

This paper presents one of a series of digests of foreign mining leg- islation and court decisions which is being repared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countrics. This interpretation of the laws of Panama has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers to who it is being referr ed through the courtesy of the Department of State.

Apr 1, 1930

By Paul M. Tyler

The alkali metals , sodium and potassium , and more particularly sodium , occur abundantly in chemical combination with other elements . The elements themselves are available in metallic form but are so active chemically that they oxidize rapidly in contact merely with the air . Potassium will even catch fire spontaneously in air , and both the metals will decompose water with explosive violence . Inasmuch as they are almost as soft as wax they are not suitable for the structural or other mechanical uses characteristic of ordinary metals , and consequently the uses of these elements even in the metallic condition are based upon chemical rather than physical qualities . Sodium metal is used largely as a commercial reducing agent , but potassium metal is rarely found outside of chemical laboratories . Numerous salts and other compounds of these elements enter largely into world trade and are commercially very important , but none of these compounds except sodium peroxide and sodium cyanide are made economically from the metals . Sodium is generally considered as rather an uncommon metal , but in point of annual tonnage produced it is far more important than mercury , magnesium , molybdenum , bismuth, cadmium, cobalt , gold , silver , or the various rarer metals .

Apr 1, 1932

By L. C. IlsLey

The work of the electrical section of the Bureau of Mines may be considered to have had its beginning in April , 1909 , when H. H. Clark was , appointed electrical engineer in the U. S. Geological Survey. The first manuscript prepared by members of this section was Miners Circular 5, which was issued in October , 1911. During each succeeding year additional papers have been published dealing with questions relating to electrical safety. Since 1916 the electrical section has also conducted laboratory investigations on flame safety lamps and gas- detecting devices and has published reports relating thereto . The following selected list of publications covering safety studies and activities of the electrical section has been prepared for the convenience of those who wish to keep themselves advised concerning electrical safety matters . The list includes only such publications as are applicable to present-day prac tices .

Jul 1, 1930

By BUREAU OF MINES

Atentative Draft of a standard smoke abatement ordinance has been prepared by a joint committee made up of representatives of the American Society of Heating and Ventilating Engineers, the Stoler Mamufacturers Association, the American Civic association, and the Fuels Division of the American Society of Mechanical Engineers. The Committee is desirous of obtaining helpful criticism and suggestions about this ordinance, which should be mailed to the chairman, Dr. O. P. Hooi, Bureau of lines, ashington, D. C. Te personnel of the committee is as follows: Dr. O. P. Hood, chairman, and Henry Kreisinger, representing the Fuels Division of the American Society of Mechanical Engineers; P. J. Dougherty, representing the American Society of Heating and Ventilating Engineers; Lloyd R. Stowe, representing the Stoker Mam- facturers Association; Everett L. Hillard, representing the American Civic Ascociation; and Osborn Monnett and Harry 3. Meller, members at large.

Mar 1, 1930

The mobility of radionuclides released into aquatic, terrestrial and subsurface environments by mining, industrial processes is an area that deserves significant scientific attention. The presence of microorganisms in these environments can influence the transport of radionuclides. Free-living microorganisms constitute mobile suspended particles that may have a radionuclide sorbing capacity higher than that of the environment. Radionuclide transport will then proceed faster with than without microorganisms. In contrast, if the majority of the microorganisms are growing in biofilms on surfaces, transport of radionuclides may be reduced. Microorganisms can directly sorb radionuclides either within the cell structure or on the cell wall. Radionuclides could also be sorbed by minerals precipitated by microorganisms. Microorganisms produce complexing agents that can influence radionuclide mobility. The involvement of microorganisms in biogeochemical processes is related to their ability to include various chemical elements and their combinations into biochemical redox reactions. Microorganisms can alter the extent of radionuclide oxidation that results in their deposition as a result of the formation of insoluble forms. Some studies have shown the bioremediative potential of stimulating reducing bacteria to use some of the soluble radionuclides as electron acceptors and thus precipitate them out of solution. The microbial involvement in providing a barrier for radioactive element migration (uranium, technetium) and the formation of ores (eg uranium) has been justified. The mediated impact of microbial activity on radionuclide migration occurs through its effect on the ambient geochemistry by geochemical speciation changes, pH changes and changes to the ambient redox potential. As the mobility of many radionuclides depends on the pH and redox potential of the environment, these microbially mediated geochemical changes can influence radionuclide migration through changes to both the dominant radionuclide species and mineral phases.

Jan 1, 2004

By John Convey

"IRON ORE was first smelted in Canada about the year 1736 at Les Forges, Quebec -a most appropriate name for such a historic locale. During these early years of the 18th, 19th, and first quarter of this century, about six million tons of ore were mined and employed in the manufacture of items ranging all the way from kettles, stoves, and cannon for the early settlers to weapons of war for the allied armies of World War I.But this symposium on iron ore is not concerned with this early period. Instead, it is concerned with the iron ore industry of today -an industry which will soon be-come one of the two most valuable mineral industries in Canada.The subject in its broad geographic and economic aspects will be introduced by Mr. Buck; Dr. Harrison will describe the geology and origin of the principal iron ore deposits; Dr. Downes will go into beneficiation as it applies to iron ores; and Mr. Gertsman will discuss primary processing. The symposium will not deal with the steel end of the industry, because that phase itself could well form the subject of a symposium."

Jan 1, 1955

By Heber E. Peterson, Sill. Claude W.

"INTRODUCTION In the usual volumetric determination of uranium, the solution containing uranium is reduced in a Jones reductor, yielding a mixture of trivalent and tetravalent uranium; the trivalent uranium is oxidized to the tetravalent state by bubbling a stream of air through the solution. The resulting solution of tetravalent uranium is titrated with a standard oxidant, generally sulfatoceric acid, dichromate, or permanganate. It seemed likely that the same general procedure could be used in determining semimicro quantities pf uranium if the conditions affecting the variables involved were understood more clearly than at present. In the method described below, the use of ferric sulfate to oxidize tetravalent uranium allows the titration to be made at room temperature in an essentially colorless solution with sulfatoceric acid. The latter oxidant in turn permits the use of the very stable indicator, ferroin; with its sharp color change and exactly reproducible blanks.Solutions of uranyl sulfate were prepared by diluting a stock solution that had been standardized gravimetrically according to the method of Lundell and Knowles (8).3/ Solutions of sulfatoceric acid were prepared according to the directions of G. F. Smith (12) and were standardized against arsenic trioxide in the presence of osmic acid according to the directions of Glen (5). The cerium solutions were stored in 18-liter carboys fitted with siphon arrangements so that the bottles did not need to be opened and protected from light in a dark cupboard. Under these conditions, even the 0.01 N solution changed by less than 1 part per thousand over a period of about 6 months."

Jun 1, 1952