Search Documents

By Albert L. Toenges

[The i~ ortance o~ S3~e, fdequnt, nQ economical tr~n~po~t~t on 8ys~em Th~a bee~ e~~~~siz8d by the introduction of mechanical loading in co 1 mines, pa.rticula:c y \'r~ e::-e ~o?oile loaciine; ~ac~ine!;j rrre u .... ed. This papar i tr_e . eco:1d or' ?. ~eries deGcribi 1{) t:;'~~11>ort:ltion G stems et1-p oyed in mech3JlizeG. f!lincs. Progre,-s ?. epo~ t J...2.t deal t ~~tirel.: ,'Ii th the l:se of rail .laulagr £or c;atl:erine tran~ortc;tion, ailc, in t-!is paper 'Ii 11 be i acuss d c .icilY rub"col'-t? ro ~ t:tto::"ing as Ie _ as ani:naJ., con-",reyor, an ot.he~ systems of rnil gatheri?1.g. ~ho l)urpo~e of this invosti-gation is, as outlined in Progress ,~ort 1, to studT . Q analyz0 v rious systems nov.: in. u"'e El.I1d to derivQ cor..cl :cicn .... tllcrcfrom.]

Jan 1, 1941

By John R. Turney

The success of the Mclaughlin acid pressure oxidatiun process has proved that a complex hydrometallurgical process can be an economically viable means of treating refractory gold ores. Homestake's Mclaughin acid pressure oxidation process was commissioned in August 1985 and ts currently operating at design tonnage of 3,000 tons per day. Mineralogical and process studies on the operating plant are discussed to show the improved understanding: of the process and its future applications. These studies are also compared with the initial process development work, thus illustrating the success of the initial scale up considerations.

Jan 1, 1989

By J. D. Stone

This paper briefly reviews the adequacy of existing management theories and practices and the managerial proficiency or competency in the South African mining industry. The investigation revealed that existing management practices are totally inadequate to enable all employees on all the levels of the mining industry to achieve the results required from them, in all aspects, at all times. As a result, the South African mining industry is gradually losing its long standing reputation as a relative cheap, competitive, and reliable supplier of minerals to the local and global markets. According to some prominent management authors and theorists, an all-inclusive unified management theory does not exist at present. In this paper the authors summarize the main aspects of a newly developed comprehensive, practical, and integrated management method. It is believed that the application of this method would significantly improve the future performance and competitiveness of the South African mining industry

Jan 1, 2010

By Robert C. Ellman

The Bureau of Mines investigated the factors that cause agglomeration of lignite by freezing during winter shipment and sought methods to avoid it. Tests showed that lignite may be freezeproofed by removal of the relatively small quantity of moisture involved in forming the frost crystals which cement particles together, or by controlling the crystal characteristics. Adding dried lignite fines proved to be an effective and superior freezeproofing method. Commercial adoption of this method has been successful.

Jan 1, 1965

By C. J. Havard, G. C. Taylor, D. G. Cook, N. C. Ollerenshaw, D. K. Norris

"The area encompassed by this report is the eastern and northern Cordillera, shown on the composite map accompanying these background papers. It extends from the 49th pm•allel to the Arctic Ocean and from the Rocky Mountain and Tintina trenches to the Interior Plains. The Mackenzie delta is included in the discussions because of the implications of the bedrock geology of the Arctic Plateau and Coastal Plain on the hydrocarbon and mineral potential beneath it.The eastern and northern Cordillera forms the back-bone of the Western Canada sedimentary basin and from it most of the principles of orogenesis and epeirogenesis relating to the understanding of the structural, depositional and fossil record of the basin have been derived. It may be divided roughly into two parts, reflecting basic differences not only in structural style but also in mineral potential. The more easterly and younger rocks generally contain hydro-carbons, coal and non-metallic minerals; the more westerly and older rocks contain metallic and industrial minerals."

Jan 1, 1970

By C. F. Starr

This paper deals with the various types of cable in use in mines, with special attention paid to their construction. There will be a few comments regarding the different insulants, jacketing materials and armouring used, depending on their application. Governing standards and the differences therein will also be discussed.

Jan 1, 1969

By D. T. White

Pressure acid leaching of nickel laterite ores typically involves the production of an intermediate product that is releached and refined to pure nickel and cobalt products. BHP Billiton is developing the Ravensthorpe Nickel Project to produce up to 50,000 t/y of nickel via a mixed hydroxide intermediate, which will be refined at its Queensland Nickel (QNI) Yabulu Refinery near Townsville, Queensland. The hydroxide precipitation flowsheet has been adapted to process high magnesium ores through an atmospheric leach stage, eliminate iron(III) as jarosite and oxidise iron(II) during neutralisation. The neutralisation conditions are controlled to precipitate aluminium, chromium and silicon, and to ensure good solid-liquid separation. Soluble impurities such as magnesium are purged with the tailings stream and will be managed over the long term by crystallisation in evaporation ponds.

Jan 1, 2006

By A. E. M. Warner, P. J. Mackey

"In 1988, two of the present authors Warner and Vahed [1] were amongst several co-authors on a seminal paper reviewing nickel pyrometallurgical operations of the era. Given that significant changes in the nickel industry have occurred since that time, including the overall political landscape, technology, the overall world energy picture, the countries sourcing nickel and finally the nickel market itself, the present authors considered it timely to provide a 2015 update. In 1988, total world nickel production from sulphide and laterite sources, including production in the former "Centrally Planned Economies"- was about 0.86 million tonnes/a, while in 2014 total world nickel production reached an all-time high of almost 2 million tonnes/a - some 230% higher. On the other hand, while in 1988, about 94% of world nickel was produced pyrometallurgically and of the order of 33% via laterites, today, about 88% of nickel is by pyrometallurgy, with some 41% from laterites, thus showing that more nickel is now sourced from laterites, a trend which is expected to continue.During the period under review, new processing technologies were developed and introduced, along with substantial improvements in both the technologies employed and the scale of operations. Significant productivity gains have been achieved in sulphide pyrometallurgy in part through more efficient mineral processing, particularly in pyrrhotite rejection, and the use of ever larger-scale process equipment. This made it possible to treat lower grade and more complex ores. The significant game-changer from a production perspective was the introduction in the early 2000s of nickel pig iron (NPI) in China via modified iron blast furnace smelting, an old technology long ago cast aside by other nickel producing countries. With the exception of the emergence of this new NPI capacity in China, in the laterite industry modernization and expansion of existing operations has been employed to gain productivity, to cut costs and/or offset the effect of declining ore grades. The NPI technology development has become a game changer in the traditional global supply and demand relationship, opening up a new frontier to supply nickel to low grade utility steel producers. One other key nickel development was the Indonesian ban on nickel ore exports effective in January 2014, thus effectively curtailing NPI production at existing Chinese plants, but on the other hand, potentially prompting new smelting facilities in Indonesia. This paper reviews and updates major pyrometallurgical sulphide and laterite operations worldwide, including changes in nickel extractive metallurgy. It also provides a brief review of new developments in pyrometallurgical operations, with special focus on the NPI process and presents an outlook of the potential future direction of the industry."

Jan 1, 2015

By S. H. Ash

In the early nineties it was observed by several European investigators and by C. S. Rice4 that an explosion could be checked and would not propagate in the parts of a mine where shale or other inert dust was present in large amounts.5 After the disastrous Courrieres explosion in France that killed 1,100 men, coal-dust explosion tests were made in France in 1907 and in Great Britain in 1908 which resulted in the conclusion that if enough incombustible dust were properly spread throughout passageways charged with coal-dust, the propagation of an explosion by the coal-dust could be prevented. In 1908 the Federal government authorized the investigation of the causes of mine explosions and of possible methods of preventing them, with the result that during 1911 the United States Bureau of Mines, after making several tests, suggested that rock-dust be used in gassy or dusty bituminous coal mines. Since that time, experiments and investigations6 have proved conclusively that widespread explosions can be prevented in coal mines by efficient rook-dusting.

Jan 1, 1930

By A. Alwasel

Musculoskeletal disorders (MSDs) threaten the wellbeing and livelihood of a large number of construction workers incurring a significant cost to society. We present a new method to monitor and diagnose MSD risks in the workplace. The sensing unit of the system is an optical encoder encompassed within a non-intrusive exoskeleton to measure the joint angle of interest. This sensor can be applied to ball-and-socket and hinge-type joints of the human body, such as the shoulder, elbow, and knee joints. The system is contactless and does not require markers or cameras. Angle measurements are acquired directly without mathematical post-processing, thereby avoiding numerical noise and drift challenges. The system is a simple, robust, and deployable, but it currently lacks resolution of parallel degrees of freedom.

Aug 1, 2013

By Yuhsuke Mizukami

Crude high Cr containing steel such as tool steel, heat-resistant steel or stainless steel is produced by dissolution of high carbon ferro-chromium into molten crude steel. In the refining process, decarburization is performed at the first stage, and deoxidation is followed in the next stage. Therefore, the equilibrium relation between dissolved Cr and 0 in molten Fe-Cr alloy after decarburization is very important when yield of deoxidizer is considered for the ovemll control and optimization of the process. It is well known that the yield of deoxidizer does strongly depend on the kinds of refractories of furnace in the secondary refining process. In the present work, the equilibrium relation between dissolved Cr and O in molten Fe-Cr alloy has been measured in a Cr2O3, MgO or Al2O3 crucible at steelmaking temperature. O contents at given Fe-Cr components have been lower in order of Cr2O3, Al2O3 and MgO crucible. The present results have been discussed based on the activities of the constituents in pure solid Cr2O3, and FeO-Cr2O3, MgO Cr2O3 and (AI,Cr)2O3 solid solutions.

Jan 1, 2003

By Bruce Macdonald

Operational monitoring of slope stability can be achieved by space based InSAR monitoring platforms. Natural and man-made rock slopes are monitored using a novel stack-based InSAR method that exploits both persistent point scatterers (PS) as well as coherent distributed scatterers (DS) such as areas of pavement and sparsely vegetated surfaces. The new method, Homogenous Distributed Scatterer (HDS)-InSAR identifies InSAR targets by using adaptive multilooking of statistically homogenous pixel neighbourhoods combined with thresholding the differential temporal coherence of each target candidate with respect to its surroundings. HDS-InSAR preserves PS and therefore forms a direct generalization to our proven DualScale-PSI method. The density of HDS exceeds that of PS by more than an order of magnitude often providing essentially continuous coverage over urban and industrial landscapes featuring a mix of infrastructure with mostly bare soils or rock surfaces. The improved coverage enables better definition of surface motion and underlying geology, which will lead to superior interpretation of the geophysical mechanisms causing the surface deformation, e.g. through improved integration with 3D deformation modeling. We illustrate the performance of our new HDS-InSAR method compared to DualScale-PSI using displacement results from Vancouver, Canada; Bingham mine, USA; and the Palabora mine, South Africa.

Jun 1, 2012

By Colin Lawrence

The Port of New York and New Jersey is one of the most heavily used transportation arteries in the world, handling nearly 40 per-cent of the North Atlantic shipping trade and directly providing nearly 230,000 jobs to the local economy. In 2004, $100 billion worth of consumer goods moved through the port. To accommodate future cargo volumes in the port, which are expected to double over the next decade and possibly quadruple in 40 years, deeper shipping channels are needed to provide access for a new generation of cargo mega-ships with drafts exceeding 13.7-m (45-ft) when loaded. Current channels within the harbor range in depths up to 13.7-m (45-ft), thus preventing carriers from using these larger ships, or requiring significant reductions in cargo to achieve lesser drafts to operate safely within the harbor. As part of the Harbor Deepening Project, the Anchor-age Channel would be deepened to 15.2 m (50 ft) below mean low water (MLW), for a length of 5,790 m (19,000 ft). The New York City Department of Environmental Protection (NYCDEP) owns, operates and maintains two existing water siphons in the harbor. Due to their shallow depth, both existing siphons must be relocated before dredging of the Anchorage Channel can be completed. Tom Costanzo, manager of capital programs for the Port Authority of New York and New Jersey (PANYNJ), says that ?While the re-location of the existing siphons under the Anchorage Channel is vital to the success of the deepening program, it is also a story of cooperation among key agencies at different levels of government resulting in improvements that will benefit the people of this region greatly.?

Jun 1, 2010

By John Nagy, Henry G. Dorsett, Murray Jacobson

Laboratory studies show that ignition of a dispersed combustible dust in an open vessel may be prevented by adequate inerting . Factors affecting the inerting requirements are -- dust concentration , spark energy , ignition temperature , composition of the substances used for inerting , fineness of dust and type of combustible . The oxygen concentration of the atmosphere and in some instances the proportion of admixed inert powder and moisture required to prevent ignition are given for 367 dust samples . Variations in inerting requirements with strength of igniting source are discussed .

Jan 1, 1964

By C. Hsu

Underground coal gasification (UCG) is becoming more popular as the reserves of good quality, mineable coal are starting to diminish, and yet the global energy demand from coal is still increasing. The purpose of this research project was to investigate cavity formation within a coal block due to the combustion reactions in the context of UCG. The cavity plays a pivotal role in the UCG process, as it is essentially the gasification reactor. Cavity formation in an in situ gasification process using the forward combustion linking method (FCL) had been investigated, and a laboratory model was created to simulate the process. The experiment was performed by drilling a U-shaped tunnel into a coal block, which was then combusted internally with air that was fed through an injection hole. A heating element (at approximately 500°C) was used to supply the required heat for combustion at the base of the injection well. The coal blocks were analysed using micro-focus X-ray tomography. The tomography results showed that the coal tended to crack along the bedding plane after a short duration of combustion, due to either the formation of clinker or the expansion of swelling vitrinite along the horizontal tunnel. The deposit was thicker at the base of the injection well compared to the base of the production well; this may have been caused by the turbulence of the air flow and the relatively high oxygen concentration at the base of the injection well. A comparison of the results with work by Daggupati et al. (2010) showed the same trend, despite the slightly different methodology applied.

Jan 1, 2014

By JOHN BIRKNBINE

MR. NEILSON was born Aug. 12, 1842, at Philadelphia, Pa., where he died Dec. 30, 1906. His business career began with his graduation, in the class of 1862, from the Polytechnic College of the State of Pennsylvania. For a short time after graduation he was instructor in mathematics at the college, and then became associated with Messrs. Booth & Garrett, chemists, of his native city: In 1867 he was sent to the Adirondack mountains to care for mining interests of the late Jay Cooke, and spent about three years there, operating the forges at Elizabethtown, Essex county, N. Y. He also prepared an interesting monograph on Catalan forges and their operations. In 1868 he published a chart showing the material progress of the United States, and the cost of certain staple products during a series of years, which is believed to be the first of its kind issued in this country. In 1870 he made a trip to the Pacific Coast, prior to entering the service of the Pennsylvania Steel Company. In 1871, when the Logan Iron & Steel Co., of Burnham, Pa., failed, Mr. Neilson was appointed receiver, re-organized the company, became' its General Manager, and spent more than four years in this work. In the meantime, he became interested in the Freedom forge of the same place, and, with Mr. Wm. Burnham and Mr. Milton Brosius, laid the foundations for what is now the Standard Steel Works. From Jan. 1, 1877, to April 1, 1890, he was General Manager of these works, and closely associated with the Baldwin Locomotive Works. In 1878 he was in charge of the first consignment of Baldwin locomotives to Europe, which, with a picked crew of men from Baldwin's, he took to Eydtkennen, Russia, and placed in service. In 1890 he resigned from the Standard Steel Works and ac-

Jul 1, 1907

By C. S. Gibson

"MOST of the mines in the Province of Ontario in Canada are multi-level operations in steeply dipping veins; yet there is an appreciable number whose de-posits are relatively flat-lying, ranging up to 45° inclination.The veins vary in width up to several hundred feet and may or may not be branching systems. The depths of mines range from a few hundred to 8,000 feet, approximately. The primary products of the underground group are asbestos, gold, silver, cobalt, copper, nickel, iron, uranium, talc, fluorspar, gyp-sum and salt.There are a few open-pit mines. The majority are temporary in type because, as the outcrops are removed, mining is continued be-low surface. Primary products of the open pits are copper, nickel, iron, magnesium and nepheline syenite.The industry as a whole employs about 50,000 persons, approximately 60 per •cent of whom have dust-exposure occupations. The definition of a dust-exposure occupation and the requirements for •dealing with same are set forth in The Mining Act of Ontario.Results of extensive and continuing studies on the incidence and progression of silicosis have been reported periodically for years past, in annual reports of the Mines Accident Prevention Association of Ontario and in papers presented at Conferences sponsored by Mcintyre Research Foundation of Toronto, all of which have been published. The information provided therein proves the effectiveness of the means being used to prevent silicosis and allied disorders."

Jan 1, 1960

By Liming Yuan

Barometric pressure changes affect air density, leading to change in the mass of the gas in the gob. When the barometric pressure decreases, the volume of gas in the gob expands, while the volume of gas contracts when the barometric pressure increases, causing the gob to breathe out and in. Although the concept of gob ?breathing? is simple, its effect on spontaneous heating of coal in the gob area is not clear. In this study, computational fluid dynamics (CFD) simulations were conducted to model the spontaneous heating of coal in longwall gob area under measured barometric pressure changes. A single longwall panel using a bleederless ventilation system was simulated. If there is no barometric pressure change, the intake airflow rate is equal to the return airflow rate. When the barometric pressure changes, these two airflow rates are no longer equal, and the difference between the two airflow rates represents the airflow rate the gob breathes in and out. The effect of inflow and outflow of gas on the potential spontaneous heating in the gob was investigated using the CFD model developed in our previous study. The effect of barometric pressure changes on the spontaneous heating was found to be dependent on the gob permeability and the coal oxidation rate. The effect of barometric pressure changes on oxygen concentrations in the gob was also examined.

Jan 1, 2010

By Charles K. Rose

The Cebolla Creek titaniferous iron deposits near Powderhorn in southern Gunnison County, Colo., were examined by the Federal Bureau of Mines as part of an overall program to investigate the Nation's titanium and iron resources. The deposits occur around the periphery of the Iron Hill stock, which underlies an area of about 12 square miles. Concentrations of magnetite, ilmenite, and perovskite arc localized along fractures in the pyroxenite stock. Mineralogical studies of composite surface samples collected in 1956 showed that most of the iron is present in ilmenite-bearing magnetite. Perovskite is the chief titanium mineral in the magnetite-rich and augite-rich types, and sphene is the principal titanium mineral in the placer material. The mica-rich rock contains approximately equal amounts of perovskite, ilmenite, and sphene.

Jan 1, 1960

By R. E. Miller

Hoisting coal using water and air is a technology which has potential to improve the economics and safety of transporting coal. The Coal Air-Lift Hydrohoist is a prototype coal hoisting system developed by the U.S. Bureau of Mines (USBM). This paper discusses the method used to regulate the supply of water to the 50-m-high hydrohoist U-tube such that the pressure difference at the bottom of the U-tube is held constant. Maintaining a constant pressure difference results in a steady flow of slurry out of the hydrohoist.

Jan 1, 1995