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By N Cusworth

The development of a resource project inevitably requires the investigation of a vast range of issues across most engineering disciplines û mining, metallurgical, chemical, civil, electrical, mechanical and environmental û as well as the geosciences. It is also a characteristic feature of the resource industry that no two orebodies û and hence no two development projects û are the same. So these technical issues have to be addressed to a greater or lesser extent in evaluating any resource projectÆs development potential. Not surprisingly then, technical issues tend to predominate when assessing the development potential of a project in the process typically referred to as ædoing a feasibility studyÆ. But the principal purpose of a æfeasibility studyÆ is to determine whether a development opportunity makes good business sense, not just whether it is technically possible. Resolution of technical issues is often seen as the primary focus of a feasibility study, whereas in reality, these technical issues are the basis upon which an asset delivery and business plan is built. This is not to say that technical issues are unimportant û they are a prerequisite to the demonstration of a projectÆs viability. The feasibility study process must therefore demonstrate that not only have the technical issues been satisfactorily addressed, but also that the broader commercial, economic and social issues have been considered in the development of a comprehensive business plan, which includes an assessment of the risk-reward profile of the proposed development. This paper will present a framework for the conduct of æfeasibility studiesÆ and provide guidance to minimum standards and best practice.

Jan 1, 2007

By Thomas J. Peters

Tungsten, silver, lead, zinc, and placer gold occur in the Cucamonga B RARE II area (no. B5174). A strata-bound, scheelite-bearing zone at the Blue Diamond prospect (fig. 1, no. 1) contains an estimated 16,000 tons (15,000 t) of identified, subeconomic resources averaging 0.16 percent tungsten trioxide (W03). There is a high potential for discovering additional tungsten resources at this property. The California-Hercules prospect (fig. 1, no. 5) ha; a mineral occurrence which contains an estimated 1,000 tons (900 t) of tactite averaging 1.3 oz silver per ton (45 g/t), 0.75 percent lead, and 0.72 percent zinc. Another occurrence, at the Blew Jordam Prospect (fig. 1, no. 4) has an estimated 100 tons (90 t) of tactite averaging 10 oz silver per ton (340 ,/t), 3.75 percent zinc, and 2.3 percent lead. There is a moderate potential for discovering silver, lead, and zinc resources at these prospects, which are in metamorphic pendants. There are a few lode gold prospects in the area (fig. 1, nos. 3, 11, 14) are on geologic structures which parallel the San Andreas Fault, northeast of the area. These deposits are not well exposed and have been historically unproductive. Placer gold in area B occurs locally in the beds of intermittent tributaries to Lytle Creek (fig. 1, nos. 10, 12, 13) in concentrations as high as $1.17 per cu yd ($1.53/cu m, at a gold price of $450 per troy oz). The deposits have no significant volume, but could be utilized for recreational panning and suction dredging. In the Cucamonga C RARE II area (No. C5174) placer gold occurrences locally contain as much as $1.23 per cu yd ($1.61/cu m). However, gravel containing the gold appears to be limited to stream beds, and does not occur in sufficient quantity to constitute resources. Recreational panning and dredging also may occur in this area.

Jan 1, 1983

The mineral industry of Benin contributed less than 1% of the 1977 gross domestic product (GDP), which was estimated at $500 million.' Other than limestone and salt, no exploitable mineral deposits have yet been discovered in Benin, which has been rated by the United Nations as one of the world's least developed nations. In 1977, the economy was further weakened by petroleum price increases and severe drought. The country continued to depend on foreign assistance, which averaged $20 million per year, to finance development projects. The country's first 3-year plan, which was put into operation in October 1977 after many delays, allocated more than $1 billion to projects in infrastructure, agriculture, and light industry. The most important infrastructure project was the expansion and modernization of the port of Cotonou, valued as an entrepôt port for the transit of goods to the neighboring countries of Niger and Nigeria. Plans called for an increase in handling capacity to 1 million tons of cargo annually, the improvement of port and cargo handling operations, and the upgrading of the efficiency of the Port Autonome de Cotonou (PAC) management system. The $46 million project was to be financed by a consortium led by the International Bank for Reconstruction and Development (IBRD) and including Canada, France, Nigeria, and Abu Dhabi. Construction was scheduled to begin in 1978 and be completed in 1980.

Jan 1, 1981

By B. J. Vorster

AngloGold South Africa region currently consists of twelve gold plants. These plants use a combined total of $20 million of cyanide per annum. Of this, the major portion (60%) is consumed at two Ergo dump retreatment plants. Historically the primary motivation for cyanide control at Ergo has been one of leach/cost optimization. However, more recently, with the increased public awareness of cyanide in the environment, a secondary but increasingly important motivation for control has been to ensure that only the minimum amount of cyanide is added to the process whilst not compromising leach performance. Following a brief overview of the Ergo process, the methodology in determining the amount of cyanide to be added is described. The paper then traces the developments in cyanide control from very basic manual systems to the current automated control system. In line with the increasingly sophisticated control systems, developments also took place in regards to the method of cyanide analysis. The development of these analysers is also discussed. Whilst cyanide is one of the major drivers, if not the major driver of gold dissolution, it cannot be viewed in isolation particularly with respect to the relationship between cyanide and oxygen as ascertained from the Elsner?s well-known equation. Consequently, in order to control cyanide addition, knowledge of the relative cyanide/oxygen profiles is necessary. Various means investigated at Ergo for pulp oxygenation have therefore been included for the sake of completeness. Finally a comparison is made of the control achieved from the current system compared to the original manual system. The knowledge and experience gained at Ergo is now being used to draw up guidelines for the installation and optimization work at the other AngloGold plants. The net effect of this will be reduced cyanide consumption for the region, which also, apart from the obvious economic benefit, translates into a reduced environ-mental risk.

Jan 1, 2001

By Sandip K. Mukherjee

This report presents the results of the economic analysis of several applicable alternatives to increase airflow in four underground coal mines. Pressure-quantity surveys were conducted underground and measurements were also made at the main mine fan(s). The existing ventilation networks were modeled using the modified Penn State ventilation simulator. The applicable alternatives were simulated. Performance data obtained from these simulation runs were utilized to conduct the cost-effectiveness analysis. The costs for each of the alternatives included capital, operating and operating costs. These costs were expressed as annual ventilation costs per active section in terms of dollars per cfm taking into account the economic life associated with each of the alternatives. The benefits were expressed as increased airflow quantity in the critical sections. A section of this report also deals with comparison of simulator predicted air quantity values against air quantity values measured under-ground. This volume constitutes Volume II of the report and contains the outputs of the computer simulation runs.

Jan 1, 1983

By N. I. Basuki, E. T. C. Spooner

"Abstract - More than 2800 published fluid inclusion data (primary inclusions) from eighteen typical Mississippi Valley-type (MVT) Zn-Pb deposits and districts were examined to study possible relationships between MVT fluid properties and metal tonnages and ore grades. The mean Th and salinity values for fifteen MVT deposits and districts are 122°C ± 21°C and 20.7 ± 2.6 wt% CaCl2 equivalent, respectively. In general, temperatures increase from pre-ore to ore stages, and salinities decrease from ore to post-ore stages. From post-ore to late calcite stages, salinity and temperature decrease with various trends within specific districts.Several conclusions are drawn: first, results show that Hanor’s (1996) salinity threshold for metalrich basinal fluids applies to typical MVT ore fluids (~16 wt% CaCl2 equivalent). Second, the lower limit of mean Th values of measured MVT deposits and districts (n = 15) of ~75°C is similar to Hanor’s (1996) observed temperature threshold for metal-rich basinal brines of ~60°C (n = 224). Third, there is no statistically significant relationship between fluid inclusion homogenization temperatures (Th) and metal tonnages or ore grades. Fourth, there seems to be a tendency for large tonnage districts/deposits to be associated with mean fluid salinities that are relatively low (~16 to 21 wt% CaCl2 equivalent) within the overall range of salinity means (~16 to 26 wt% CaCl2 equivalent). There is also a correlation between higher ore grades and higher salinities. Finally, comparison with other sedimentary rock-hosted Zn-Pb deposit types shows a trend of salinity decrease and temperature increase from MVT, sandstone-hosted and diapir-related Pb-Zn deposits, to vein-type and Irishtype Pb-Zn deposits, and then to sedex deposits. However, more data are needed for sedex deposits. The salinity threshold for significant Zn-Pb transport decreases to =~10 wt% CaCl2 equivalent at ~250°C. This study suggests that fluid inclusion analysis during exploration may be useful in assessing ore-forming potential (threshold salinity) and possible ore grades (salinity)."

Jan 1, 2002

By Joseph Grumer

Theory pertaining to the exchangeability of fuel gases on appliances has been extended to exchanges of propane or butane with mixtures of these. In particular, new considerations were developed bearing on the hazard of an occasional emission of carbon monoxide and flashback and blowoff possibilities. The new considerations involve using current requirements for approval of liquefied petroleum gas appliances. These requirements were used to predict allowable tolerances in chemical composition of liquefied petroleum gases for existing appliances. In addition, changes in gasline pressure were computed which may be substituted in place of fuel exchanges during testing of appliances,

Jan 1, 1962

By Carl D. Ealy

Work is being done to web enable the FHWA Deep foundation Load Test Database. Originally designed to function in the client server environment via modem, access to the database both for data maintenance and user queries has been upgraded to take advantage of the Internet and current and future information technology innovations. The DFLTD will be part of an Automated Geotechnical Information and Design Aid System, the object of which is to assist those involved with managing and maintaining our nation's highway infrastructure. The system will also meet the needs of university and other research institutions for a statistically meaningful source of high quality data for the development and verification of improved analysis methods, in-situ testing methods, etc.

Jan 1, 2002

By P. W. van Deventer

?Soil quality is the capacity of a soil to function, within ecosystem and land use boundaries, to sustain biological productivity, maintain environmental quality, and promote plant, animal and human health?. In the long-term, vegetative rehabilitation of mining wastes aims at, as far as possible, the proper ecological integration of the reclaimed area into the surrounding landscape, which is sustainable and requires minimal maintenance. A certain succession pattern is therefore needed. Recent ecological concepts recognize the role of the substrate?s quality and nutrients in affecting the rates and directions of succession patterns. Although pedogenesis and eventually soil quality in mine waste are not well known, monitoring of soil quality parameters in kimberlite mine tailings reveal a remarkable establishment and or improvement of specifics oil quality indicators. During the same time the vegetative cover?s total functionality as well as reproductive ability improved. Functions of soil, and thus soil quality, can be assessed at the field, farm, ecosystem, pedosphere, and global scale. It is recognized, however, that management of soil becomes increasingly difficult at larger scales, but for demarcated mine waste sites it is possible to ameliorate and manage and assess soil functions and quality. Therefore the significance of the study is the following: soil functions and quality become inseparable from the idea of system sustainability, and are considered as key indicators of ecosystem sustainability on rehabilitated mine tailings material.

Jan 1, 2008

By Ralph D. Gift

This report describes a program of research to evaluate methanometry in coal mines. The program commenced by conducting an extensive state-of-the-art survey. Details of the survey are presented which includes a rating of various types of instruments that can be used to detect and record methane gas. Laboratory test data, on mine instruments tested are presented together with results from a computerized statistical analysts.

Jan 1, 1972

By C. Nexhip, S. Sun

Critical to understanding and controlling phase mixing and separation in metallurgical processes, is the development of reliable experimental techniques to measure interfacial properties of melt systems. A series of experiments has been carried out to determine the effect of oxygen potential on the surface tension of liquid copper. Using an electromagnetic levitation method, a surface tension-oxygen chemical potential adsorption isotherm was produced for the Cu-O system at T 1400 K. The surface tension results show good agreement with the literature values e.g. within 3 per cent for pure copper. The Belton `ideal' adsorption isotherm was applied, and the following equation derived to best fit the experimental data ? =1251-77.5 1n41+ (2.79x105 . pO1/2)](mN.m Using this equation, the surface tension of copper was calculated/predicted as a function of oxygen potential at 1400 K, and showed excellent agreement with the experimental values. This confirmed that the adsorption behaviour of oxygen in liquid copper is ideal. The saturation coverage of oxygen on the surface of liquid copper was determined to be T0 = 6.65 µmoles.m,-2 corresponding to an area per adsorbed oxygen atom of ao ? 25 Å2. These values agree well with those cited in the literature, and our experimental data cover a very wide range of oxygen potential (10-5 to 10-17 atm). Keywords: levitation melting, surface tension, Cu-O alloys, oxygen potential, adsorption isotherm, surface coverage.

Jan 1, 2004

By George T. Faust

The petrographer engaged in examining the products resulting from the beneficiation of ores, and rock minerals is constantly required to develop new means acid methods of assaying microscopically the results of such operations. From time to time investigators have published descriptions of apparatus that have aided in solving problems in processes of physical separation. Thus, in 1919, Coghill and Bonardi 3/ published a paper covering the application of the binocular microscope and camera lucida to the microscopic analysis of pulverized ores. Similar work has been published by Schneiderhohn 4/ Schwartz 5/, and Head and his associates 6/, 7/, 8/. The present paper goes further and considers application of the polarizing comparison-microscope to problems directly concerned with mineral dressing where it is desirable to compare analogous products, and in addition it suggests new uses in various related fields. This work was conducted under the cooperative agreements of the Southern Experiment Station of the Federal Bureau of Mines and the University of Alabama.

Jan 1, 1940

By X. Pan

Slag-metal equilibrium experiments were conducted at 1500ºC and1580ºC under 0.03 atm, 0.05 atm and 0.83 atm CO partial pressures using silica and Cr-oxide crucibles. The complex slags belonged toSiO2-CaO-Al2O3-MgO-FeOx-CrOxand the metal phase to the Cr-Fe-C-Si-(S) systems. The carbon saturation of the metal phase was avoided using oxide crucibles and thus the results are pertinent to ferrochromium refining slags and processes. From equilibrium data and thermodynamic calculations, the CrO /(CrO+Cr2O3) ratio in the slag was determined as 0.75, 0.80 and 0.86 under 0.83 atm and 0.05 atm of CO pressure at 1500ºC and 0.03 atm and CO pressure at1580ºC, respectively. The results clearly demonstrated that a higher chromium content of the metal results in higher Cr in the slag, and chromium in slag decreases with increasing SiO2. The results were also sensitive to the crucibles used as these oxide crucibles saturated the slag either with respect to SiO2or Cr-oxides. It was also demonstrated that the relative amount of CrO in the slag was higher when SiO2crucibles were used in accord with thermo-dynamic calculations. Iso-concentration curves for carbon and chromium of the metal phase in equilibrium with the slag were drawn on a pseudo ternary SiO2? (AI2O3+CaO+MgO) ?(Cr2O3+Fe2O3) diagram. The activity coefficients and activities of carbon and chromium of the metal phase were also calculated from the experimental data and available thermodynamics information and were plotted as iso-activity curves in the same pseudo ternary diagram. Keywords: chromium, slag, equilibrium

Jan 1, 2004

By L. A. Morely

The overall objective of the subject contract was to investigate the application, economic, and safety considerations of electrical-shock prevention techniques applied to surface and underground mines. Volume I of the four-volume final report starts by summarizing all research performed, and synopses of the three other report volumes are included. The balance of this volume concerns one major task of the contract, the protection of maintenance personnel. After specifying the scope of work for the task, electrical is defined, and needed ground-fault relay characteristics to prevent ventricular fibrillation are established. This is followed by an analysis of alternating-current systems, a comparison of these systems with respect to body currents, and the advantages and disadvantages of the various ground-fault protection techniques. An analysis of direct-current systems for off-track vehicles is then covered. These analyses form the basis for the research recommendations which along with suggestions for future research, conclude the report volume.

Jan 1, 1982

By R G. Barker

The NZ Minerals Industry Association has continued to advance the interests of the minerals sector through leading the establishment of a Minerals Industry Advisory Committee, and the preparation of a technology strategy with funding assistance from the Foundation for Research, Science and Technology. The current moves mirror those of more than 30 years ago when a government initiative led to a resurgence of exploration through amending the mining legislation, redirecting Government research priorities and tax changes. The economic and political and commercial environment in 2001 is very different from that of the 1960s and success of these new initiatives depends on the continuing support and involvement of all sectors of the minerals industry, and building an improved relationship with the Government and the public.

Jan 1, 2001

By G J. Lyman, F S. Bourgeois

As the prices of metals slide, financial control of mineral processing operations becomes more and more important. Control of a mineral processing operation implies measurement of grades, recoveries and losses, with every effort being made to recover more product from the same feed. Shareholders become more concerned with the transparency of the operations and the corporate governance.There is only one way to achieve this and this is by sampling and making good use of the results of that sampling. Sampling systems that provide only 'rough' figures are not good enough. Similarly, a competitive position in the marketplace demands close control of product quality. Maximisation of product output demands that the product just meet the specification so that product yield is maximised. Decisions based on precise sampling results carry less risk that those based on imprecise results.This paper reports some recent advances in sampling theory that permit full quantification of sampling distributions, not just the sampling variance as has been possible in the past. These advances can be used together with simulation methods to tie down sampling precisions and develop calculations that quantify decision making risk when using the sampling results. A number of examples illustrate the use of the new advances and a final example indicates the development of risk analysis curves in the coupling of sampling precision to sale of a commodity.CITATION:Lyman, G J and Bourgeois, F S, 2015. Sampling, corporate governance and risk analysis, in Proceedings MetPlant 2015, pp 27–34 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By R. Venugopal, Saxena. V. K., U. Sankrityayan

"There is a dire need of a technology which can break the mineral interfaces to enhance liberation with minimum energy consumption in mineral beneficiation processes. Understanding of mineral crystal system and interfaces is essential to develop such methodology. So, this study is carried out to find out the role of mineral crystallography in milling and liberation. Data related of mineral crystallography, Vickers Hardness Number, Bond Work Index and beneficiation processes were collected from literature and detailed statistical analysis has been carried out to establish a correlation among these parameters. It was found that atomic weight and cell parameters shown statistically significant relationship with Vickers Hardness Number of minerals, which controls the milling characteristics of ores. Liberation characteristics of five different kinds of ores were analyzed considering the types of interfaces between valuable and gangue minerals. It was found that phase interfaces play vita role in liberation and coarser liberation can be achieved in the minerals of incoherent crystal systems like manganese and zinc ores. Study of this subject can help us to understand the effect of stress wave propagation in solids and its effect on crystal interfaces. It can also help us to design a technology of future to break the mineral interfaces.INTRODUCTIONCommunition is energy intensive mineral processing operation and consumes up to 2% of the total electric power generated in the world. Energy consumption due to comminution is increasing every year as there is growing needs to exploit lower grade ore bodies and process rejects (Blazy et al., 1994; DOE, 2005). Low grade ores require crushing and grinding to liberate the valuable minerals which are further separated from gangues by various beneficiation methods like gravity separation, floatation, leaching etc. Currently, comminution methods are selected based on the reduction ratio and energy consumption but effect of grinding methods on subsequent processing methods specially on liberation also need to be studied to optimize the entire beneficiation process. Most of the attempts made in past to minimize the energy consumption in milling to enhance the mineral liberation were focused on compression mechanism, chemical additives, thermal treatment, microwave treatment and electric disintegration (Kilpelm and Austin, 1982; Norgate and Weller et al, 1994; Bearman et al., 1997; Kumar et al., 2010; Wang el al., 2011; Singh et al., 2012). But the role of mineral crystallography on milling and liberation behavior of minerals not fully explored yet."

Jan 1, 2013

By B. P. Martinez

In response to a request from the President, the Department of the Interior joined with other agencies in a comprehensive study of the land and water resources of the New England-New York region. As part of this study, chemical engineers of the Bureau of Mines have visited 1,025 mineral-industries plants to inventory the waterborne wastes of mineral origin, discharged by the mineral industries of the New England-New York region. Four-hundred and sixty-two of these plants disposed their wastes to a public sewer of some type, but waste control remains a problem for moat of them. The 1,025 plants are discussed in main industry groups according to their production: Chemical and allied products. Stone, clay, and glass products. Iron and steel and their products (except machinery). Nonferrous metals and their products. Electrical machinery. Machinery (except electrical). Transportation equipment. Miscellaneous mineral industries.

Jan 1, 1956

By Jerome Apt

This manual has been prepared fur the help and guidance of underground coal mine operators. It details both common and unique engineering methods by which the respirable dust, which is generated in coal mines, can be controlled. This document was compiled by Apt, Bramer, Conrad and Associates, Inc. under contract number H0111464, issued by the U. S. Bureau of Mines and forms Volume II of the final report. This contract was authorized by and executed pursuant to the Federal Coal Mine Health and Safety. Act of 1969 (P. I. 91-173; 83 Stat. 742).

Jan 1, 1972

By Y. He

The nature of the density distribution in a gas-solid phase fluidized bed for dry coal separation is an important factor in influencing the performance. However, during coal processing, fine slime would mix with dense medium of magnetite powder and accumulate in the bed, and its influence will affect the density of the bed. The mathematical model of the density distribution with fine slime behaviour was studied in an experimental laboratory system. The functional relationship between the density of the air dense medium fluidized bed and the coal slime content were fitted, applying the principle of least-squares method with damping factors. With the model, by analysing the trial testing data, the mechanism of the density distribution of the bed was studied and applied to a coal separation test with a pilot scale separator. Keywords: dry coal separation, gas-solid phase, model fitting.

Jan 1, 2002