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By A G. Shellsh, R J. Henham, J R. Foley

The Porgera Gold Mine, west of Mt Hagen in PNG is a large open pit and underground operation currently producing gold at the rate of almost one million ounces per year. This deposit has produced some 8.8 million ounces to-date and has current reserves of 103.4 million tonnes @3.2 g/t Au. The Porgera Joint Venture has invested over $A1 billion in infrastructure in this project. Technical management of this operation involves the interrogation of some 700 000 metres of diamond drilling, some 50 000 blastholes per year, and very large volumes of laboratory, geotechnical, environmental and production reporting data. Over the past seven years this data has been consolidated into a single centralised, relational database which now acts as the single reference point for all the technical application systems used for surveying, grade control, production reporting, deposit evaluation and modelling. Data transfer to application programs and management systems is controlled by the centralised database, this process at times involving a two-way, real-time, binary data transfer. The benefits of a specialised database application include security and integrity of the data asset, ease of access, and performance in a multi-user environment. This replaced fragmented, inconsistent data sets stored inefficiently as individual, unindexed, variably formatted files associated with the different application programs. Most importantly, the database has allowed mine management at all levels to make timely, confident investment, cash flow and optimisation decisions as it provides the primary link between the deposit and operational data sets on one hand, and the application programs and management and performance measurement systems on the other. This paper discusses the economic value and importance of technical data in terms of the resource asset and the means by which this data is being managed and used at Porgera.

Jan 1, 2000

By McClelland. John J.

This Bureau of Mines report discusses recent applications of water in-fusion technology to control dust in U.S coal mines and presents recommended guidelines for determining coal seam infusibility. The techniques required to use water infusion are presented in detail. A Bureau case study indicated that water infusion reduced dust levels by 68 pct along a longwall plow face, bringing this section into compliance with the Z.0-mg/m3 Federal dust standard. Similar studies conducted by Occidental Research Corp. under a Bureau contract show water infusion at two longwall double-drum shearer operations produced dust reductions ranging from 38 to 50 pct. Water infusion was found to be cost effective, aver-aging 5 cents per ton.

Jan 1, 1987

By Willis H. Carrier

PARTICULAR interest in the ventilation of deep mines, especially those in South Africa, has been created by a very complete system of cooling of the world's deepest mine, the Turf shaft of the Robinson Deep in Johannesburg. The writer visited this mine in January, 1936, and again in 1937. During these visits and subsequently, a considerable part of the theory involved in rock cooling in tunnels was developed and this has been checked by practical observations of the rates of rock cooling made within mines. The purpose of this paper is to set forth the method of attack of the mine problem. The cooling or air conditioning of mines by the use of mechanical refrigeration was not wholly new 1-5 when the Robinson Deep installation was made. The first mine to be cooled was the Morro Velho mine, in Brazil. The first installation in this mine was put into operation in December 1920, the refrigerant being ammonia.5 The surface cooling gave considerable benefit but it proved inadequate as greater depths were reached, therefore in 1929 two centrifugal refrigerating machines were installed at the 6000-ft. level. These were used in conjunction with the surface cooling system to furnish additional cooling at the lower levels. This later installation used Carrene as a refrigerant. This nonflammable refrigerant, having a boiling point of 104º at sea level, insured reasonable safety, since all parts of the machine operated at subatmospheric pressure. Very favorable reports have been received on the effectiveness of this installation, but no recent data are available. An interesting feature of that plant is that the condenser water is cooled by spraying it into the exhaust air from the mine at the base of the ventilation upcast, which permits the water to be cooled within a few degrees of the wet-bulb temperature of the air entering the upcast, and the only water that has to be supplied for condensing purposes is that lost by evaporation, or about 0.5 per cent of the volume circulating through the condenser. This plan affords an ideal means for the removal of the heat load from the refrigerating system, and of course also from the mine itself. In many mines, however, especially those in South Africa, there is no

Jan 1, 1938

By Hans von Michaelis

There has been a renaissance in gold and silver extraction and recovery that has taken place over the last fifteen years, since the price of gold was freed from the $3510~ level. Despite major advances in such areas as carbon adsorption processes for gold recovery, refractory gold ore treatment, crushing and grinding, process control, etc., there still remain several gold and silver mineral processing frontiers. Frontiers related to environmental management present significant challenges especially in the USA. More than ever it is appropriate to optimize total economics by adopting a "systems approach" that integrates mining, mineral processing and environmental management.

Jan 1, 1993

By Karel SPIRKO

The one-dimensional mathematical model of unsteady-state heat conduct ion through multilayer (wall and floor of airway consist of several layers of material and rock) and two-surface (dry and wet surfaces) airway wall and airway floor with convective heat and moisture transfer between their surfaces and mine air with time dependent changes of temperature and humidity has been developed on the basis of introduction of acceptable simplifications of description of heat and moisture transfer between rock mass and mine air. The analytical solutions for calculation of the surface temperature of any type of surface of airway wall/floor and for calculation of water vapour pressure near the wet surfaces at given time are obtained by means of the model presented. These solutions are illustrated for the case of general harmonic course of air temperature and humidity. Balance of heat and moisture transfer between surfaces of airway wall and floor and mine air is solved by an iterative method in the partial sections of airway. The temperature and the humidity of mine air on the outlet of each partial section of airway at given time are its resolutions and they are the input data for following partial section. By this way it is possible to solve complicated dynamic changes of mine air temperature and humidity in an air way system by relatively simple mathematical apparat.

Jan 1, 1991

By Jacob T. Wainwright

AS a means for increasing the efficiency in modern blast-furnaces by supplying to them blast of a much higher temperature than is now possible, the writer offers as a suggestion a modification in the construction of regenerative hot-blast stoves. Stated briefly, the plan proposed is to pre-heat both the gas and the air for its combustion in a manner similar to that generally adopted in Siemens openhearth furnaces. After thus carrying the temperature of the stove to a point much higher than that common in hot-hlast stoves, the cold blast passes through it. Without entering into the details relating to the reversing valves and the system of flues, the general plan may be outlined as follows, referring to the accompanying drawings: The valves are so placed in heating up the stove that the blast-furnace gas enters at B, Fig. 1, and the cold air for combustion at A. Ascending in flues, F and E, respectively, combustible gas and air meet and mix in the combustion-chamber, I. Flowing through K, they descend through the flues, G and H, escaping through the chimney. In this manner the walls of the combustion. chambers, I and L, are highly heated, and the right-hand side of the stove is carried to a higher temperature. By reversing the valves, blast-furnace gas enters at C and cold air for combustion at D. Both are pre-heated in their ascent through the flues, G and H. They burn in the combustion-chamber, L, and the hot gases of combustion, flowing through K, I, E and F to A and B, heat the left-hand side of the stove. In this manner the stove is carried to a temperature greater than that of those now generally in use, in which air and gas are burned without preliminary pre-heating. In the plan proposed, that side of the stove will, of course, be relatively cooler through which cold air and furnace-gas last passed in its ascent to its combustion-chamber. After having sufficiently heated the stove in the manner outlined, the cold blast is admitted through all the flues, A, B, C and D. It ascends through the highly-heated regenerative material to the chambers at the top and descends through the flue, P, Fig. 2 (dotted

Jan 1, 1889

By N. S. Raymon

As part of an interegency agreement with the Energy Research end Development Administration to develop unproved refractory materials for use in coal gasification processes, the Bureau of Mines reviewed the literature to determine the effect of steam, H2, CO, and CH4 as well as the alkali metal oxides K2O and Na2O on refractory materials. Emphasis was given to the performance of high-alumina castable and fired refractories to conditions expected in coal gasification processes. Approximately 85 references were reviewed with 40 cited in the text. The literature was found to contain little data directly applicable to the selection of refractory lining materials suitable for use under the conditions of temperature, pressure, and gas compositions expected in second generation coal gasification reactors.

Jan 1, 1976

By Gae On Kim, Ki Baik Kim, Suk Hoon Kang, Tae Kyu Kim, Sanghoon Noh

"Advanced radiation resistant oxide dispersion strengthened steel (ARROS) is being developed as a fuel cladding tube material for future nuclear reactor system applications. The research activities consist of advanced radiation resistant ODS steel development and fabrication technology development of ODS steel structural components. One candidate material with a chemical composition of (in wt%) Fe-10Cr-1Mo-0.5Mn-0.1V-0.25Ti-0.35Y2O3and was selected as representative materials, and this material was named as the advanced radiation resistant ODS steel (ARROSTM).On the basis of this ODS steel composition, an optimized fabrication process of structural components such as plates, sheets and tubes has been established through various process conditions in mechanical alloying, hot/cold working, and heat treatment processes. These R&D activities are expected to contribute to the realization of ODS materials in the future.INTRODUCTIONA sodium-cooled fast reactor (SFR) is being developed at the Korea Atomic Energy Research Institute (KAERI) with a view to economics, safety, reliability, and sustainability. The prototype Gen-IV SFR with a capacity of 150 MWe is under design, and this prototype reactor is scheduled to operate from 2028. For a commercial SFR system application, it is necessary to develop an advanced structural material having both high creep strength and irradiation resistance at high temperatures (Jeong, 2014). Oxide dispersion strengthened (ODS)steel is one of the most promising structural materials because of its excellent creep and irradiation resistance on the basis of uniformly distributed nano-oxide particles with a high density, which is extremely stable at high temperatures under a neutron irradiation environment for a prolonged operating period(Kim, 2016). As the first step, several batches of ODS steel were designed and the candidate samples with a 2 kg scale each were fabricated by mechanical alloying, hot isostatic pressing and hot rolling processes. The mechanical properties of these samples were evaluated. Up to now, two candidate materials with chemical compositions of (in wt%) Fe-10Cr-1Mo-0.5Mn-0.1V-0.25Ti-0.35Y2O3 was selected as representative materials, and these materials were named as the advanced radiation resistant ODS steel (ARROSTM).The next step was to optimize the fabrication process of the ARROS compositions for in-core structural components such as the fuel cladding tubes of a SFR. An optimized fabrication process of fuel cladding tube with a composition of ARROS has been established through various process conditions in mechanical alloying, hot consolidation, hot/cold working and heat treatment processes. Joining technologies of the ODS steel tubes is being developed using solid-state welding such as magnetic pulse welding, friction stir welding and diffusion boding. It is expected that the development of ARROS will contribute to the realization of a commercial SFR with high economics and sufficient safety in the future. In this paper, the study of fabrication process of ARROS structural components is introduced."

Jan 1, 2017

By Dipak C. Talapatra

This report describes the development of guidelines for design, inspection and maintenance of automatic couplers. In order to devise the guidelines, performance requirements for automatic couplers were carefully established. This was clone through a comprehensive survey of coupler manufacturers and extensive observation of automatic couplers in service in a broad spectrum of mines. The capability of the couplers to withstand the demands of the mining environment in terms of strength characteristics, gathering range, curve negotiability, and other factors were all carefully evaluated. An analysis of coupler related accidents for the years 1972-1976 was carried out to provide information on the safety and reliability of existing automatic couplers. This formed an important input to the development of the guidelines. It is expected that these guidelines will he useful to coupler manufacturers for establishing designs for improved automatic couplers, and to mine operators for maintaining their couplers in a safe and good operating condition throughout their expected lifetimes. This report is in two volumes: Volume l - Technical Report Volume 2 - Design, Inspection, and Maintenance Manual

Jan 1, 1977

By C. E. T. White

Although trace amounts of Indium are found in many ores, commercial production of the metal has come almost exclusively from residues, flue dusts and slags generated by Zinc recovery operations. Our paper attempts to summarize the various approaches used to recover Indium from these by-products. Some comments on production and price trends are included as well as our views on future availability.

Jan 1, 1982

By N. Agron-Olshina

The application of the QEM*SEM image acquisition and analysis system to the measurement of the mineral matter in coal and the materials in fly ash is described. A new sample mounting technique was developed using iodinated epoxy to provide a backscattered electron contrast between the coal, the mounting medium and the mineral matter. Several comprehensive and detailed species identification programs for silicate minerals and materials were developed to analyse the 1000 count x-ray spectra used for the measurements. Case studies are presented to demonstrate the capabilities of the new technique to distinguish different coals and fly ashes by their mineral and material composition rather than by conventional chemical analysis. Applications of the new technique are aimed at demonstrating that composition and size distributions obtained from OEM*SEM measurements can be used: 1. to characterize coal with respect to combustion problems in power stations, 2. to characterize coal for fine coal cleaning, 3. to characterize fly ashes in relation to problems such as erosion in combustion systems and the ease of precipitability in dust collection facilities, 4. to refine the classification systems used in marketing coal for pulverized fuel firing and fly ashes as a component of cement and building materials.

Jan 1, 1992

By Arsenio Enriquez, Adrian Deneys

"Rio Tinto through its subsidiary Kennecott Utah Copper Corporation (KUC) and Praxair have implemented the CoJet® gas injection system for copper anode refining. The system provides the capability to melt on average 60 to 70 tons of scrap copper per heat (with acceptable NOx emissions). The system has demonstrated the potential for tuyere-less sulfur and oxygen removal using coherent jet technology.This paper describes the process concept, system development, laboratory testing, implementation, current operation and ongoing developments."

Jan 1, 2009

By H. Laitala, M. Lampi

Metso Outotec has developed a wide range of solvent-extraction technologies over decades and has introduced Metso Outotec VSF®X solvent-extraction plant. Standardized and modularized, Metso Outotec VSFX Plant provides a novel way to design, manufacture, transport, install, operate, and maintain solvent-extraction plants far better than in the past with highly sustainable and safe methods. For the customer, this means fast-track projects with savings in means of time, costs, quality, and operation. Sicomines and Metso Outotec have together implemented and commissioned a modern and efficient copper solvent-extraction plant. Plant commissioning and ramp up of the plant were fast and the plant is now operating efficiently. This paper presents Sicomines’ VSFX copper solvent-extraction project and gives a sight into operating figures for the plant.

Jan 1, 2023

By Noel W. Kirshenbaum

Difficulties and costs of transport markedly affect Canadian mineral producers because of distance from markets, weather conditions and rugged terrain. The chemical and physical nature of sulphide concentrates presents additional difficulties in handling and transport, resulting in higher costs which are ultimately borne by the mineowner. Troublesome properties include the thixo-tropic character of wet concentrates, freezing, susceptibility to autogenous heating, and fine particle size causing spillage and dusting losses. Canadian mineowners and shippers must contend with these problems and with stringent regulations governing the maritime shipping of concentrates. A "systems approach," in which complementary techniques in materials preparation, handling and transport are integrated, could reduce freight costs and losses for those selling concentrates, facilitate operations for those carrying and handling them and, in some cases, improve metallurgical processes in smelters receiving them.

Jan 1, 1969

By Howard C. Homeyer

Coal and water are the two basic external feedstocks required for a coal gasification project. The WESCO project in northwest New Mexico, a joint undertaking of Texas Eastern Transmission Corporation and Pacific Lighting Corporation, will require about 25,000 tons of coal and approximately 7.5 million gallons of water each day to produce 250 million cubic feet per day (MMCFD) of pipeline quality substitute natural gas (SNG). The coal and water supply arrangement with Utah International, Inc. assures the project of an adequate supply of these two vital feedstocks.

Jan 1, 1974

By J Field

Many aspects of water use in mining are driven by the technical requirements for water. There has been little consideration given to both the safety and the health requirements. Workers in the mining industry are exposed to water from a range of treated and untreated sources. The intended use of this water dictates the required quality of the water, sometimes with limited consideration for contact with miners. Particularly for underground workers, there is exposure while working in and walking through groundwater possibly contaminated by hazardous substances. Where controls are inadequate the outcomes of this exposure can result in disease, illness and injury û the costs of which can be significant. The situation could also arise where, due to the lack of human exposure, the controls are unwarranted and the financial cost unjustified from a health perspective but warranted from an equipment management standpoint. In addition to the health aspects, water can impact on a range of safety issues resulting from high pressure usage, dust suppression, fire fighting and other processes. The protocols and procedures in place need to consider the safety issues in addition to managing water usage. The current state of water management in mines from an occupational health and safety perspective has been ascertained from a survey targeting underground and surface coal and metalliferous mines. This survey considered the health and safety issues associated with water use, the types of surveillance, control protocols and the strategies that the mines have in place to manage the health and safety risks associated with water systems. The results assisted in the identification of potential occupational health and safety risks associated with water systems and the management processes that may be appropriate from a risk management perspective. Health and safety issues are often neglected but remain critical issues affecting the value of water to the mining industry.

Jan 1, 2006

By Timothy W. Ellis, John A. Howes, Roger D. Feldman

The new generation of more powerful, energy-intensive devices for communications, industrial production, energy storage and other purposes is creating new challenges to guard against environmental harm and protect national security. Many devices are designed, used and disposed of in a linear, rather than circular manner. This causes scientific, legal and economic issues because the life-cycle costs of components are not adequately considered. Dealing with these issues in isolation from each other can lead to unintended consequences. New models to confront these issues are being defined. This paper suggests a fundamental tool for dealing with material science issues while taking into account the engineering, economic and policy perspectives. That tool is the development of a true, levelized cost of energy storage model with a wide spectrum of inputs for comprehensive analysis. This paper will discuss inputs and the process which can yield meaningful, useful comparisons among batteries and energy-intensive products.

Mar 1, 2018

By P. S. Dunn, A. D. Rollett, H. D. Lewis

"The results of preliminary work on the modeling and measurement of the heat transfer coefficients of metal/mold interfaces is reported. The system investigated is the casting of uranium in graphite molds. The motivation for the work is primarily to improve the accuracy of process modeling of prototype mold designs at the Los Alamos Foundry. The evolution in design of a suitable mold for unidirectional solidification is described, illustrating the value of simulating mold designs prior to use. Experiment indicated a heat transfer coefficient of 2 kW/m /K both with and without superheat. It was possible to distinguish between solidification due to the mold and that due to radiative heat loss. This permitted an experimental estimate of the emissivity, ~ = 0.2, of the solidified metal.IntroductionA feature that distinguishes casting processes from welding processes is the presence of an interface with a low heat transfer coefficient between the mold and the casting. Especially when chill casting, the interface delays the start of solidification and increases freezing times significantly. By comparison welds can be assumed to have a very high heat transfer coefficient. The heat transfer coefficient controls such phenomena as folds and laps on the surface of castings which can be crucial to the acceptability of a casting. The time delay for the start of solidification influences the occurrence of cold shut defects. The standard mold material for uranium casting is high quality graphite which is an excellent refractory when used in vacuum and coated with a refractory wash. Graphite is an effective chill material and has a thermal diffusivity approximately twice that of uranium. Experience has shown that practicable superheat without mold pre-heat is not sufficient for avoiding cold shut defects when casting in graphite molds.TheoryIt is possible to calculate the position of the freeze front s, as a function of time, t, the superheat and interface heat transfer coefficient, h, [1]. However, the value of h cannot be obtained explicitly. The Virtual Adjunct Method (VAM) [2] offers a method for extending the standard equation for an insulating mold where s is proportional to the square root of time. By considering the effect of the interface to be equivalent to finite thicknesses of mold and metal, the following quadratic equation is obtained,"

Jan 1, 1986

By Graham Cooke, Abhishek Lahiri, Animesh Jha, E. Jeya Kumari

"CO2 reduction by alternative energy devices such as wind-power, electric vehicles utilize rare-earth elements (REE) in several forms; such as in piezo-electric devices, batteries and magnetic materials. In 2010, the 95% of Rare Earth supply is controlled by China, compared to USA being dominant supplier in the 1980s. The dependence upon a single source of lanthanides has prompted the utilization of lower grades of titaniferous mineral concentrates, which often have rich seams of REE. We propose a new methodology, which utilizes the low-grade minerals for the extraction of synthetic rutile and also significant quantities of REE. We demonstrate the alkali roasting of lower grades of mineral concentrates and subsequent leaching in an aqueous medium for preferential flocculation of REE during the extraction of synthetic rutile. Changes in mineral structure during alkali roasting and leaching determine flocculation of REE and permit their separation at the front end of unit process.The physical chemistry and crystal structure of minerals in equilibrium with alkali and aqueous medium play an important role, which we explain by demonstrating the changes in the crystal structure. The quantification of separation of RE oxide via chemical analysis suggests that it may be possible to separate rare-earth oxides between 50 and 80% of the initial concentration in the non-magnetic fractions of ilmenite, for example. The microstructural and X-ray diffraction analysis points out that the presence of alumina and roasting with potassium based alkali enhances the separation and flocculation of rare-earth elements at the front end of the process after roasting. The process allows the recovery of CO2 generated by recycling into the process for the regeneration of alkali."

Jan 1, 2011

By Oliver Bowles

The exingencies of a world war have brought home to the American public, especially the people of the. Eastern States, the urgent need for conserving fuel. Transportation problems in the East have created an unprecedented situation wherein fuel-oil supplies are greatly restricted, and the consequent increase in demand for coal further complicates the problem of transporting and storing that commodity. People should awaken to the need for utilizing every possibly means of conserving to fuel, even to the extent of reducing the temperature in their homes.

Jan 1, 1942