Search Documents

By RV. Ramanl, KV. K. Prasad, M. Swaminathan

The objective of the research in this project is to develop a knowledge based expert system for aiding the planning of mine ventilation systems. This system focuses on mine ventilation system design from a coal mine dust control standpoint. It is recognized that mine ventilation system design is an engineering problem involving not only rote numerical calculations to solve the pressure quantity problem but also substantial judgement and expertise to analyze a problem situation and Interpret the results of an algorithmic program. The thrust of this project is to i) extract this knowledge from public domain sources and recognized experts in industry, government and academia, 11) represent this knowledge in the form of IF ... TI-IEN rules in an expert system (ES) and 111) interface the developed expert system with a mine ventilation network analysis program vis. PSUMVS (Pensylvania State University Mine Ventilation Simulator). By providing the numerical computing and qualitative reasoning aspects of mine ventilation system design in a single Integrated system, better quality decision support will be made available to apprentice users.

Jan 1, 1988

By Q. Han

A modified cast-on method has been developed to reinforce aluminum castings with steel insert. Defect-free bond between the steel insert and the aluminum casting has been consistently obtained. Data obtained from a push-out experiment indicated that the bond strength was much higher than that obtained using the Al-Fin approach. This paper introduces this modified method in four sections: the coating of the steel pins, the cast-in method, microstructure characterization, and the bond strength. The section on the coating of the steel pins contains coating material selection, electro-plating technique for plating Cu and Ni on steel, and diffusion bonding of the coatings to the steel. The section on cast-in method deals with factors that affecting the quality of the metallurgical bond between the coated steel and the aluminum castings. The results of microstructure characteristics of the bonding are presented in the microstructure characterization section. A push-out experiment and the results obtained using this method is described in the section of bond strength/mechanical property.

Jan 1, 2015

By Harold M. Wrigth

El siguiente estudio refiere al diseño y costo de construcción de las plantas concentradoras, así como el de plantas de beneficio realizadas en la provincia de British, Columbia. Para ello, el autor, quien diseñó aproximadamente 16 plantas para el tratamiento de minerales en el mencionado lugar, propone la dfusión y aplicación de este tipo de máquinas en nuestro país, considerando los tonelajes, las ubicaciones, resistencia del terreno, el flow sheet, para sentar las bases del diseño de los equipos.

Jun 20, 1954

Discussion of the paper of R. J. COLONY, presented at the New York Meeting, February, 1921, and issued With MINING AND METALLURGY No. 169, January, 1921. R. J. COLONY (author's reply to discussion).-The work of Sosman and Merwin on the system lime-ferric oxide, mentioned by Mr. Rankin, was not overlooked. When studying portland cements and portland-cement clinkers petrographically, however, the lime-iron compound was difficult to correlate with the very definite dicalcium ferrite described by those investigators, which possesses such well-defined optical properties. In portland cements, the calcium ferrite (or ferrate?) is an indefinite, fuzzy, and generally amorphous, or apparently amorphous substance that is distributed interstitially with respect to the other grains, from which it was very difficult to derive any satisfactory results. For this reason, the writer, tentatively, chose to regard it as related to the aluminate, and assigned to it the composition 3CaO.Fe203, which may be incorrect, however, as Mr. Rankin suggests.

Jan 8, 1921

By K Morrison

Australia’s ageing population means that by 2050 there will be 2.7 people of working age to support each Australian aged 65 years and over compared with five working people per retiree today and compared with 7.5 in 1970 (Swan, 2010). This means that there is going to be a greater demand on social services – for medical and aged care – from a smaller private income base. How will this gap be met? Australia is fortunate in that it has vast resources of mineral wealth; from iron ore, nickel and gas in Western Australia to the giant copper and uranium deposits at Olympic Dam in South Australia.The prospect of a meaningful profit based tax on this vast mineral wealth has been lost through Australian government’s handling of the issue in 2010 and with an industry fiercely opposed to the prospect of a mining tax. Hence, new ways of thinking are required. This paper looks at the issues facing the implementation of a novel scheme whereby Australia leases the mineral resources it extracts and thus derives income over the decades the metals are in-use in pipes, wires and structures with a premium paid for unreturned material or that used in dissipative applications. Applicable minerals could include copper, aluminium, nickel and rare earths. If Australia simply digs up and sells the metals once, the buyer becomes custodian of that resource and they benefit from controlling the future ‘above-ground’ resource stock.A complementary driver for a leasing scheme is the increasing importance of chain-of-custody following initiatives of the Responsible Jewellery Council with gold and diamonds, now with the potential to extend across commodities. The Australian minerals sector could thus position itself as a premium supplier with high social and environmental credentials.Recognising the implementation challenges, this paper includes a review of how such a system could be enforced to ensure that the metal is tracked throughout its life. It concludes with a discussion of the rates and terms should such agreements hold and suggestions for institutional arrangements for enforcing compliance.

Nov 22, 2011

By Charles T. Ford

In 1971, Bituminous Coal Research, Inc~ established a program to provide the coal industry with the necessary information and technical capability to investigate and evaluate potential problems concerning trace elements in coal and coal-related materials. The initial efforts at BCR in developing or adapting analytical procedures for the precise determination of trace elements in the parts per million to parts per billion range were detailed in a report titled "The Development of Analytical Methods for Determining Trace Elements in Coal and Coal-related Products." A subsequent reports contained descriptions of reliable analytical methods refined by BCR for determining mercury in coal and coal ash and also in coal mine water. his paper reports initial progress in applying recently-acquired trace-element analytical capabilities to solving potential coal industry problems. In this case, the effect of a coal-cleaning process on the distribution and removal of potentially harmful trace elements in coal was evaluated. Coal cleaning offers the possibility of controlling potentially harmful emissions resulting from combustion of large tonnages of coal by removing the pollutants prior to combustion.

Jan 1, 1977

By T Peters

The Kibali Gold Mine is currently comprised of several open pits, a 3.5 Mtpa underground mine and a 7.5 Mtpa processing plant. Development of the underground operation commenced in December 2012, with initial access established through twin surface declines, followed by the commencement of a blind sink 8 m diameter rock hoist shaft in March 2013. Stope production started in December 2014 with ore and waste trucked to surface. The 755 m deep blind shaft sink was completed in August 2015 together with the cutting and equipping of three main station levels. Two of these levels provide access for the establishment of the underground materials handling system as well as the main dewatering system for the mine. This paper covers the process of determining the optimal location of the Kibali hoisting shaft relative to project-specific critical factors, and then focuses on the design and implementation journey associated with the off-shaft development that essentially encompasses the Material Handling System (MHS) for the mine. The journey starts from the findings of the previous owners Feasibility Study (FS), a subsequent Optimised FS, followed by detailed engineering through to implementation. It was identified during implementation that a significant change in the designed off-shaft layout was required following detailed underground geotechnical and hydrogeological investigations. In addition, the paper provides details on the MHS performance since commissioning to steady state, and on key learnings relating to the overall project process.

Mar 29, 2023

By Andrew Budek

"Analytical and experimental work has shown that achieving the full inelastic lateral capacity of a pile may require the formation of a plastic hinge below ground level, in the pile shaft. The confining action of soil about the pile shaft was further been shown to greatly enhance the ductility capacity of the pile. An experimental program was therefore undertaken to build in the effect of external confinement through the addition of a GFRP jacket to the subgrade plastic hinge region. Two piles were thus modified, and compared to an unjacketed pile in a test rig which simulated a subgrade moment pattern and soil confinement. The ductility achieved by the jacketed piles was found to be substantially lower than an unjacketed control specimen. Failure mode of the jacketed specimens was also undesirable, involving complete tendon rupture and sudden loss in capacity IntroductionSeismic loading of concrete pile shafts can result in a demand for inelastic response. In the case of a superstructure supported by a single pile (i.e., a pile-column forming a single-column bridge pier, in which there is no rotational restraint at the top of the pile}, a plastic hinge will form below grade, at a depth which varies with soil properties and above-grade height of the center of seismic mass.In the case of a superstructure supported by multiple piles, there is rotational restraint, and the connection will experience inelastic action first. However, development of the full lateral inelastic capacity of the pile may call for the formation of a second, subgrade plastic hinge (fig. 1 )."

Jan 1, 2005

Valuers of mineral properties should be aware that accountants are a major user of their opinions of value. Reliance by accountants can range from obtaining comfort that book values in balance sheets are not overstated to establishing values by which to assess the fairness of a takeover offer. Accountants using mineral property valuations clearly can't be expected to have the same level of expertise as the valuer and ""second guess"" the valuation. But they do have an obligation, under the ASC guidelines and their own professional standards, to'check the logic and reasonableness of the valuation before being able to rely on it. This means reviewing the valuation report for general sensibility, discussing the methodologies and assumptions with the valuer and being satisfied as to his competence and independence. This paper outlines how accountants use mineral property valuations, the level of scrutiny applied to such valuations and the problems commonly encountered in practice by accountants seeking to rely on them. The paper also explains how values of-mineral properties are established in company balance sheets and why these often differ, quite validly, from fair market values.

Jan 1, 1994

By Brett Schug, Caelen Anderson, Sohail Nazari, Carlos Cristoffanini

"The Haile gold mine in South Carolina is increasing the automation level of its processing plant in order to improve operational stability. One step toward this goal is the application of a digital twin concept to provide virtual instruments. Haile has engaged Andritz to implement virtual instruments at its grinding area hydrocyclones and at its tailing thickener underflow pump. These virtual instruments provide density values in a traditionally difficult location for reliable slurry density measurement. The digital twin is a first-principles integrated design engineering with advanced simulation (IDEAS) simulation model, connected in real time to the control system. Results have been promising, with the virtual instrument values matching the physical instrument under normal operating conditions and showing better prediction under upset conditions. Haile plans to use the virtual instruments as optional process control parameters.OceanaGold’s Haile gold mine is located near Kershaw, SC, about 80 km (50 miles) southeast of Charlotte, NC. This location was first mined in 1827 and has produced gold through several operating periods since then, including a heap leaching operation from 1985 through 1992. In October 2015, OceanaGold acquired Romarco Minerals, the previous owner of the Haile operation.The current operation began in 2017 as an openpit mine with additional underground resources. The nameplate throughput is 5,760 t/d (6,350 stpd) ore, and 2017 production was 3,345 kg (118,000 oz) gold, with 3,968 to 4,384 kg (140,000 to 155,000 oz) gold expected in 2018. Proven and probable reserves exceed 85 t (3 million oz) gold at a grade of 2 g/t (0.06 oz/st) gold. The process, as shown in Fig. 1, includes a primary jaw crusher, comminution with a semiautogonous grinding (SAG) mill and ball mill circuit, flash flotation, rougher flotation, regrinding, pre-aeration, carbon-inleach leaching, carbon elution and regeneration, cyanide recovery, electrowinning and refining. The Haile operation’s inaugural gold pour took place Jan. 20, 2017. Mine life is expected through the year 2030."

Dec 1, 2018

By S. Gering, R. Ruiz, C. H. Calderon-Arteaga, J. Barrios

"INTRODUCTION Located in the northeast corner of Zacatecas State, Mexico, the Peñasquito Operation is comprised of the Peñasco and Chile Colorado (Brecha Azul) deposits. Open pit mining (pre-stripping) began in 2010 and full production commenced during 2011. The open pit mines feed both a sulphide concentrator (mill) and a heap leach pad. The project is owned by Goldcorp, Inc. Penasquito is a poly metallic deposit with Au, Ag, Zn and Pb being recovered as payable metals. As a consequence of lower grade ores expected with advancing mine-life Peñasquito is facing a declining metal production profile. To maximize returns and asset value plant modifications including the addition of a carbon pre-float circuit and a pyrite leach circuit to improve recovery are currently being undertaken. This carbon pre-float circuit will enable the recovery of precious and base metals from carbonaceous sediments. This material is currently being stockpiled. With the associated increase in complexity in the process circuit, the requirement of the ore control system to accurately predict ore feed characteristics is critical to maximizing metal recovery at the Penasquito operation. The addition of the carbon pre-float circuit was also a key driver in allowing the Chile Colorado open pit to be developed. These conditions alongside Goldcorp’s drive to increase profitability, and maximize net asset value has created challenges. These challenges are numerous and are multifaceted, however the ability to accurately route materials from the ore control system is critical to site success, and some of these challenges have been overcome by the adoption and implementation of a new ore control (OC) technology. Examples of these technological innovations in the ore control program are discussed in this paper and include improvements in geo-modeling, material routing and reconciliation. Successful implementation of these elements has led to significant improvements in selectivity, performance, and data management, while reducing the variance between planning and execution, thus helping to drive overall improvement across the operation."

Jan 1, 2018

By Rees J. Llewellyn

Improved product development, assessment methods and evaluation studies of materials for oil sands applications have traditionally focused on low and high stress abrasion and slurry erosion resistance mechanisms, because they were considered to be the predominant wear modes prevailing in oil sands mining, transportation and bitumen recovery. More recently with the very successful introduction of oil sands hydraulic transportation systems, there has been increasing use of crusher systems in which materials of construction are also required to have good toughness and gouging abrasion properties to withstand impact and the severe indentation and ploughing forces that are involved. To assess material property requirements for mitigating this additional wear mechanism, jaw crusher gouging abrasion tests using a modified ASTM G81 procedure, have been carried out on a range of wear materials of interest for oil sands mining service. The method involves a comparison of the wear losses that occur for reference and selected test plates when a controlled amount of standard feed rock is comminuted in a laboratory jaw crusher. Among the classes of material evaluated have been Q&T plate steels, austenitic manganese steel, chromium and chromium molybdenum white irons as plain castings and in laminated forms and also chromium carbide and tungsten carbide overlaid wear plates.

May 1, 2004

By Jay Tuttle

THE spiral stoping method of mining was first seen by the writer at the Granby Consolidated Mining, Smelting & Power Company's Hidden Creek mine, at Anyox, British Columbia. Where the method received its name, or by whom it was named, is a question, but it was employed by the Granby Company at their Phoenix mine, in the Boundary district, B.C., as early as 1901-02 after they had tried unsuccessfully other methods at that large, law-grade property. its adoption there was suggested by two miners, John and Steve Swanson, then working at Phoenix, who had previously been employed in the hard iron-ore mines of Michigan and Wisconsin, where they had learned this system of mining. The method proved successful at Phoenix and also, later, at the Company's Hidden Creek mine at Anyox, where some 40,000,000 tons, or more, of ore was mined in this manner during a period of about thirty-five years.

Jan 1, 1939

By G. M. Scamans

In the past ten years there has been considerable penetration of aluminum automotive body sheet (ABS) into automotive structures. The exponential increase in demand is resulting in major investments in heat treatment and finishing capacity across the globe. Line speed and tonnage throughput is limited by the continuous heat treatment (CHT) floater furnace rather than the cleaning and pretreatment section where electrolytic treatments that offer higher line speeds should come into favour and roll coating of pretreatment should predominate. The capacity limiting surface texturing pass will either be eliminated or moved to the finishing line or a dedicated mill. The key to making aluminum both embedded carbon and cost competitive with steel for more and more affordable classes of vehicles lies in recycling of both prompt scrap and, in the longer term, end of life vehicle scrap. For the first time scrap separation technology is available that can compete effectively with hand sorting and can sort aluminum shredded vehicle scrap into wrought and cast alloys and then into individual alloy groups. The challenge is to use more end of life scrap in alloy formulation whilst at the same time extending the property range in terms of both strength and formability.

Jan 1, 2015

By G. M. Scamans

In the past ten years there has been considerable penetration of aluminum automotive body sheet (ABS) into automotive structures. The exponential increase in demand is resulting in major investments in heat treatment and finishing capacity across the globe. Line speed and tonnage throughput is limited by the continuous heat treatment (CHT) floater furnace rather than the cleaning and pretreatment section where electrolytic treatments that offer higher line speeds should come into favour and roll coating of pretreatment should predominate. The capacity limiting surface texturing pass will either be eliminated or moved to the finishing line or a dedicated mill. The key to making aluminum both embedded carbon and cost competitive with steel for more and more affordable classes of vehicles lies in recycling of both prompt scrap and, in the longer term, end of life vehicle scrap. For the first time scrap separation technology is available that can compete effectively with hand sorting and can sort aluminum shredded vehicle scrap into wrought and cast alloys and then into individual alloy groups. The challenge is to use more end of life scrap in alloy formulation whilst at the same time extending the property range in terms of both strength and formability.

Jan 1, 2015

By J. E. McConnell

No. 1 Electric Furnace and Billet Casting Shop, located in Plant No. 4 adjacent to our new 12 inch merchant bar mill, represents Inland Steel Company's first venture into both electric furnace steelmaking and continuous casting. Construction of the shop began in September, 1968 with excavation and foundation work, followed by awarding of general construction and major equipment contracts from December, 1968 to April, 1969. The first heat was tapped from No. 90 furnace on December 18, 1970, and the first cast attempted on December 29, 1970. The rated shop capacity is 500,000 tons per year of semi-finished billets and blooms, and was justified on the basis of approximately 85 percent of the product mix falling into the special bar quality category of steel grades. Auxiliary equipment has been designed into the shop to pursue free machining steels, including leaded and tellurized grades. The start-up and operation of the shop for the first year was essentially based on a two-part philosophy: 1. Initially operate with the "open stream" casting technique to accomplish machine shakedown and operator familiarization and training. 2. Operate with special bar quality, or "submerged casting", practices, make necessary refinements and gain customer acceptance

Jan 1, 1972

By E. P. Youngman

Zirconium, formerly distinctly a rare element, is rapidly becom- ing of rather extensive commercial importance. Economic features of the zirconium industry, together with general information regarding the metal and its compounds, are discussed in a separate paper, to which this paper is a supplement. In addition to giving a brief discussion of the four or five de- posits that so far have proved to be commercial sources of the element, this circular summarizes available data (including some hitherto unpub lished material from the files of the Bureau of Mines) upon other occur- rences, including many of scientific interest only, of the two commercial. minerals, zircon and baddeleyite, and also data upon some of the minor minerals, such as eudyalite and cyrtolite, which have attracted addition- al interest in recent years because they are frequently richer in hafnium than the more common zirconium minerals.

Jun 1, 1931

By Nathanael Hudson, Ruel A. Overfelt, Sushil H. Bhavnani

"In the aerospace and automotive industries, complex shapes exist which require casting. The problem with these cast parts is the empiricism required to develop the casting process and the accompanying time and expense to develop that process.There has been an interest in using fluidized beds to allow molding sand to better encapsulate the complicated surface geometries of lost foam patterns. Fluidization coupled with a mixing jet helps to homogenize the sand through stirring and may improve the integrity of the casting.At issue is the hydrodynamics of the sand and air around the foam pattern. The commercial package PHOENlCSTM is used to simulate the flow around the pre-casting foam geometry. Employing a two fluid approach, each component is considered a fluid that interpenetrates the other phase. To this end, the kinetic theory of granular 'flow for the sand phase was incorporated into the re-compilable PHOENlCSTM code.The results of this study consist of time-averaged void fraction patterns, with voidage being defined as the fraction of air in the mixture, around the foam pattern submerged in a two-dimensional fluidized bed. The model was benchmarked against past fluidized bed experiments. In order to better understand the dependence of the void fraction pattern around the lost foam pattern, certain physical parameters are varied and the resultant void fraction maps are predicted with the model. Physical parameters such as the aspect ratio of length to width, the placement of the mixing jet, and different mixing jet velocities are varied to illustrate the dependence of the time-averaged void fraction on those variables.Results consistently indicate the presence of channeling around the lost foam pattern, with the extent of the channeling and void formation reliant to a greater degree upon the placement of the mixing jet, and to a lesser degree on mixing jet velocity and aspect ratio.The increase in radial position of the mixing jet from the bed centerline had the desirable effect of granting the churning benefits of a penetrating jet, while at the same time minimizing the formation of excess void fraction at the top of the pattern."

Jan 1, 2001

By Serge Rudchenko

A study to determine the potential use of retaining structures in open pit backfilling. Research and review of the open pit mine environment, mine waste disposal, and past and current use of retaining structures. A development of specific structures, the culvert/ tunnel concept, and an anchor block retaining concept. The cost benefit of retaining structures used for in-pit backfilled waste.

Jan 1, 1981

By C. W. Davis

This report follows the same general scheme as did its predecessors; it begins with a dissertation on some phase of ore-testing, continues with results of investigations of ore-treatment methods and of metallurgically important analytical processes, and concludes with an exposition of tests made by established methods on typical ores selected as representative of certain mining districts. One of the first things that is done after an ore has been received is to look at it under the microscope. Microscopic examination serves as an important complement to chemical analysis in interpreting the percentage composition in terms of minerals. If it has been found difficult to treat an ore, the reasons for this action and indicated methods to overcome the difficulties may be ascertained by testing with a microscope. For example, failures in selective flotation have been traced to intimate mineral association and changes in mineral surfaces through incipient oxidation. The importance of surface stains or tarnishes and the presence of adhering slime particles have been found to be responsible for the difficulty experienced in the treatment of certain gold ores.

Jan 1, 1938