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By M. S. Ünal

Creation of 3D model of coal seams is a tedious and time consuming operation. Computer aided 3D solid modelling of coal seams can be performed in a fast and detailed manner. However, in case of having tectonically disturbed coal seams where faults may be observed, expert opinion is necessary to decide the geometry of the coal seam. The aim of this study is detection of fault zones with computers by using drill hole data. Firstly, a digital database is generated by using the drill hole data. Surface models of the layers are produced by applying triangulation method on coal seam roof elevations. The generated surface is divided into small squares and consequently dip and dip direction values are calculated for each square. Variograms for dip and dip direction are determined and maps showing the variation of dip and dip direction are generated by using geostatistical methods such as kriging and co-kriging. Examination of disconformities observed on estimation maps created by kriging and co-kriging clearly reveals the extension of faults. The method used in this study is applied to detect fault lines of a known mine field. 3D solid modelling of the coal seam has also been performed by using conventional cross-section method. The results of both methods were in good agreement. Identification of major faults by using the method introduced in this study could certainly simplify 3D solid modelling of coal seams.

Aug 1, 2013

By Diego L. Romero, Joy P. Romero

"IntroductionThe purpose of this paper is to explain the theory and demonstrate the industrial applications of electrostatic separation. Wabush Mines' use of this type of processing for the concentration of iron ore is unique in the industry. Other minerals are concentrated electrostatically but the process is not widely used.Typical minerals separated by electrostatic separation techniques are:Non-ConductorsAnhydriteApatiteBariteBastnasiteBerylCalciteChrysotileCorundumDiamondEpidoteFeldsparsFluoriteGarnetGypsumHornblendeKyaniteAcmiteAugiteBrookiteCassiteriteChalcopyriteChromiteColumbiteCopperDaviditeEuxeniteFerberiteFrankliniteGalenaGoldGraphiteHematiteMica (Biotite)Mica (Muscovite)MonaziteOlivinePerovskiteQuartzScheeliteSideriteSillimaniteSpheneStauroliteSulphurTopazTourmalineXenotimeZirconConductorsIlmeniteIlmenite-( High Iron)IlvaiteKoppiteMagnetiteMarmatiteMolybdenitePyriteRutileSamarskiteSphaleriteTantaliteWolframiteWulfeniteThe limitations of this process are:1. There must be a difference in conductivity between the minerals being separated.2. The size range must not be very wide.3. The specific gravity of minerals being separated should be similar or the minerals to be pinned should be lighter. 4. The feed must be dry.5. The particle shape should be more or less uniform. 6. The feed must not be high in true middling particles."

Jan 1, 1989

By Jan Drzymala, Przemyslaw B. Kowalczuk

Froth flotation is widely used for upgrading of ores and other materials. Efficiency of flotation depends on many parameters, including type, chemical structure and dose of flotation reagents. Selection of a proper frother in flotation depends on the material used, necessary dose of frother and its selectivity. The selectivity of flotation can be characterized by proper separation factors and indices. In this paper separation selectivity and power of frothers were evaluated basing on separation data for a given material and frother, plotted as the recovery of the useful component in the concentrate versus the recovery of the remaining components in the tailing. Such a plot is called the Fuerstenau upgrading curve. The selectivity was defined as the location of the whole upgrading curve in relation to no and ideal separation lines, expressed on the scale from 50 (no separation) to 100% (ideal separation). In turn, the flotation power was defined as the dose of frother to reach a certain upgrading level at which recoveries of the useful and unwanted components are equal. The power and selectivity of frothers were determined for the Kupferschiefer stratiform copper ore floated in the presence of a fixed amount of xanthate and varying doses of frothers using a laboratory flotation machine. Basing on the separation results for different poly(propylene glycol) (CnH2n+1O(C3H6O)mH, CnPm) and poly(ethylene glycol) (CnH2n+1O(C2H4O)mH, CnEm) alkyl ethers, it was found that the concentrate yield and recovery of copper as the useful component in the concentrate were greatly influenced by the type and dose of frother. However, the same results plotted in the form of the Fuerstenau upgrading curve clearly indicated that the selectivity of frothers was similar, while their power was different. It proves that both selectivity and power of frothers are useful parameters for characterizing flotation systems.

Jan 1, 2016

By A. G. Roach

MILLING of Nova Scotia gold ores began in 1862 with arrastras and wooden stamps and has progressed to heavier stamps followed by tables and other forms of concentration for the recovery of the sulphides. Chlorination and cyanide leaching of the concentrates has been practised, and in 1936 the combined amalgamation and all-sliming cyanidation plant of Seal Harbor Gold Mines was built. It has since been found that it is not necessary to cyanide the full tonnage and now only the concentrates are being so treated. From his experience in this enterprise, the writer presents the accompanying flow-sheet and supporting comments. While he has not the temerity to maintain that it is the best or only flow-sheet for Nova Scotia gold ores, he feels that it warrants thoughtful consideration by members of the milling fraternity of the Province. THE ORE The gold in Nova Scotia ores occurs both free and intimately associated with sulphides-chiefly arsenopyrite. Much of the free gold is quite coarse and crystalline. This is especially true when it occurs in white quartz. When in the slate, it is usually in thin plates and scales, frequently coated and discoloured. The values bound up in the sulphides are not amenable to amalgamation and must be recovered by other methods-concentration, followed by smelting or fine grinding and cyanidation. While high freight and treatment charges apply on concentrates shipped from the Province to smelters, a considerable quantity has been so disposed of in the past. However, it is hoped that a customs cyanidation plant will soon become available to producers of these auriferous concentrates in Nova Scotia.

Jan 1, 1938

By V. S. Papezik

Pyrophyllite, a hydrous aluminium silicate, is used mainly in the ceramic industry and to a lesser extent as a filler in the manufacture of paper, rubber, insecticides and baby powders. Commercial deposits of pyrophyllite in North America are restricted to the "Avalon Zone" , a belt of late Precambrian volcanic and sedimentary rocks that extends along the eastern flank of the Appalachian orogenic belt f rom Georgia to Newfoundland. The only commercial Canadian pyrophyllite deposit lies near Foxtrap on the A valon Peninsula of Newfoundland. Here, steeply dipping lenses of altered pyrophyllite rock occur in a north-trending rhyolite belt near the contact with a granitoid pluton. The altered rock is massive, light greenishyellow and contains varying proportions of pyrophyllite, sericite and quartz with lesser amounts of diaspore and traces of barite and rutile. A lteration was produced by acid solutions, either derived from or activated by the intruding pluton, at temperatures of 250° to 270°C and pressures not exceeding 2 kbr. The largest of the Foxtrap pyrophyllite lenses, discovered in 1897, was mined intermittently f rom 1903 until the early 1950s. The present owner of the mine, Newfoundland Minerals Limited, acquired the property in 1959 and ships between 27, 000 and 36,000 tonnes annually to th e company plant in Lansdale, Pennsylvania, for use in ceramic tile.

Jan 1, 1984

By Julian V. Simela

Conventional methods of underground surveying use theodolites/total stations and 3D laser scanners to obtain information about the underground environment. Current methods of geo-referencing these instruments to a mine reference system include triangulation, trilateration and resection. However, despite technological advancements, surveying procedures have remained slow, laborious and relatively unchanged during the last half-century. Recent innovations in the robotics community have shown that automated mapping of underground mining tunnels can be undertaken using 2D/3D laser scanners. These techniques have the potential to, in turn, improve upon current underground surveying and mapping methods. Automating surveying and mapping using current surveying tools without changing the setting up procedures or removing current constraints, or even changing the type of equipment used, does not change the status quo. The problem of moving from a static, tripod based surveying and mapping system to an unconstrained mobile surveying and mapping system is the subject of this paper. A current challenge for automated mapping is the ability to automatically geo-reference a mobile mapping system to a mine reference system. For a mobile mapping system that uses a horizontally mounted 2D laser scanner to gather data of the underground environment, the challenge of determining its position and orientation within the mine environment is magnified even more. This paper introduces Mobile Automated Scanner Triangulateration (MAST), a technique under development at Queen?s that is designed to geo-reference a mobile mapping system to a mine reference system for the purposes of underground mine surveying. MAST quickly and automatically determines scanner 2D position and orientation (azimuth) in a mine reference frame by using minimal human input.

Aug 1, 2013

By Sudarshan Martins

The measurement of acoustic signals produced by a tumbling mill has been previously used to determine the operating state of the mill and correlate the variations of the sound intensity with the operating conditions of the mill. Separately, the discrete element model (DEM), a software simulation of the mill, was developed to provide insight into the operation of the mill. Presently, there has not been much work reconciling the DEM simulation of the mill with the acoustic signal. Working from basic principles of linear, time-invariant systems, agreement between an acoustic DEM simulation and the measured signal is sought. First, the impulse response function of the mill is measured. The DEM provides the forces applied to the mill shell as a function of time. A convolution of these simulated shell forces and the transfer function gives the simulated acoustic signal. This signal is compared to the measured acoustic signal, both in the time domain and the frequency domain. Finally, a discussion of the results is given.

Jan 1, 2012

By A. Atrafi, L. Barroilhet

The top size of particles in the flotation of potash ores, which can be as large as 4 mm, exceeds by far the top size in other flotation plants. It is then understandable that while long chain amines are used in the flotation of fine fractions (below 0.8 mm) of potash ores the coarse particle flotation also requires an extender oil. While new and very promising fluidized-bed flotation machines (e.g. HydroFloat) constitute a significant development in the flotation of coarse particles, in the area of extender oils, as reviewed in 2007 by Strathdee, Gotts and McEachern, there have been no new developments to replace the industry standard asphaltene-based carcinogenic extenders. This situation first of all results from the experimental problems that arise when water-soluble minerals like sylvite are to be tested in saturated brine. Both oils and longchain amines are water/brine insoluble. The oil with the amine dissolved in it can however be emulsified and then used as an extender oil. Such oil droplets must wet KCl particles and the emulsion must be stable to avoid handling problems. In this paper we test the use of the phase inversion technique as a method of studying wettability of KCl particles by the oil in saturated brine, and the effect of amine dissolved in this oil on the wettability. The results show that this relatively simple technique can be used to characterize the wettability of fine KCl particles by the tested oil and to determine the effect of added amine on it, and so it can be useful in selecting proper extender oils.

Jan 1, 2016

By Alan B. Morrow, William A. Poe

"Minerals processing operations are constantly challenged with improving production rates, yields, energy efficiency and process stability. Advanced Process Control has proven to be an effective tool for improving operations by capturing the full process capabilities consistently. However, the velocity of applying the technology as well as the sustainment of these significant benefits has been hampered by the usability of the software and adaptability of the applications.Some of the new technology developments that improve the usability and adaptability of advanced process control include:• modern and intuitive user interfaces,• customizable models to support unique process behavior,• fast and flexible OPC connection tools,• automated model building,• integration with first principles dynamic models and• improved performance monitoring.This paper will briefly discuss the new technology developments that have improved the usability and adaptability of advanced process control and how this can affect minerals processing operations.In today’s environment, Minerals Processing plant managers continuously face new challenges and requirements including:• higher energy efficiency,• increased run lengths,• reduced product quality variability,• reduced emissions,• higher availability, and• lower operating costsOperating a unit to meet these challenges in real time is not easy for operators and conventional process control systems. However, innovatively using existing technologies in Minerals Processing plants can improve operations on a minute by minute basis and reap significant benefits.Advanced Process Control (APC) can extract the maximum performance benefits from existing equipment while respecting plant operating constraints. Expensive capital projects to upgrade equipment are not always necessary. Advanced Process Control can deliver significant economic benefits by maintaining the plant at its most profitable point as conditions change."

Jan 1, 2016

By C. Beaudry

Outline ? General Geology of Frieda River Project Area ? Exploration History ? Geology of Porphyry Deposits ? Porphyry Resource ? Update of Nena Deposit and High-Sulfidation Mineralization ? Nena Resource

May 1, 2006

By Jinsuo Zhang

Investment in coal resource development is affected by a variety of uncertain factors. Investors can make a flexible, strategic decision to achieve the value of risk implicated in those uncertain factors. Therefore, based on real-option theory, we identified key uncertain factors that affect a coal resource investment project, and revealed the formation mechanism of option value in coal resource developing investment project. Then, a multi-factor decision making model was established for a coal resource development investment project with random changes of coal price, interest rate, convenience yield and production cost. Finally, we tested the model and analyzed relevant parameters by applying living data. Our results indicate this model reflects the value of risk implicated in uncertain factors for coal resource development investment, and is able to determine a critical point of decision making change when coal price and production cost varym respectively. By means of parameters analysis, the convenience yield has a positive effect on the project value. The interest rate has a negative effect.

Aug 1, 2013

By Hiwa Salimi, Foley. Stephen R, Loghman Moradi

Common water-miscible organic solvents including DMSO, DMF, methanol, ethanol, acetone and THF in combination with HCl and low concentrations of H2O2 were investigated for dissolution of gold. THF showed the best result demonstrating that gold powder could be completely dissolved in 1.5 hours in 1.0 mol/L HCl and 0.2 mol/L H2O2. No complete gold dissolution was observed for the rest of solvents even after 24 hours. The rate of gold dissolution was measured by dissolving gold wire in THF/HCl/H2O2 mixture. The rate of gold dissolution in optimised condition was 75 g m-2 h-1 at room temperature and significantly increased to 590 g m-2 h-1 by raising the temperature up to 60 oC. Although a THF/HCl/H2O2 mixture showed a slower dissolution rate in comparison with aqua regia, however the applied conditions are considerably milder which is highly promising for gold leaching in an industrial scale.

Jan 1, 2015

By Harry Piers

A RAPID glance over the history of The Mining Society of Nova Scotia shows that in its fifty years of service, which it is now rounding out, the Society has had an honourable career, rendered signal service to the mining industry of the Province, and helped to shape and improve legislation bearing on our mines and minerals, besicles publishing very many excellent papers and subsequent discussions thereon dealing with all subjects in its field of activity. THE GOLD MINERS? CLUB OF NOVA SCOTIA: The Society has the distinction of being generally regarded as the oldest mining fraternity in Canada ( 1). Iris the direct outgrowth or reorganization of The Gold Miners' Club of Nova Scotia, which was organized in March, 1887, at a period when the gold mining industry was very prominent in the Province. Mr. Geo. W. Stuart, who, in 1934, was the only living member of the parent association, informed me that the seventeen Charter Members of The Gold Miners' Club were John H. Anderson, Charles F. Andrews, A. B. Cox, Clarence H. Dimock, George E. Francklyn, L. W. Getchell, John E. Hardman, Alonzo A. Hayward, Major R. G. Leckie, W. L. Libbey, Edward M. McDonald, G. F. McNaughton, George A. Pyke, H. A. Sanders, C. E. Willis, Benjamin C. Wilson, and George W. Stuart. Others joined later in the same year.

Jan 1, 1937

By G. Beckstead, L. Gormely, R. Zimmer, K. Hanneman, B. Nethery

As part of the EIS and permitting activities for the Pogo Mine in Alaska, a risk assessment study for the water management plan was carried out. The basis for the study was a site water volume and contaminant balance model. Probabilistic modeling was carried out using the @Risk Monte Carlo simulation package to investigate the frequency, quantity, and quality of discharges under varying assumptions. The results were used in discussions with regulatory officials as part of the permitting process for the project. The simulation allows probabilistic modeling of key environmental parameters based on input frequency distributions involving both quality and quantity of flow. When combined with predictions of water treatment plant capacities and removal efficiency, this was very useful for defining the likelihood of important regulatory outcomes. Based on the model, certain project modifications were made. Using the simulation as a basis, ongoing dialog with regulators led to consensus that all potential risks have been considered and mitigated for the Pogo Mine according to their likelihood and severity, and that regulatory requirements would be achieved. The paper describes the model and some of the applications for which it was used.

Jan 1, 2005

By M. Knot

Fans delivered to the Russian Federation, and eventually to countries of the former U.S.S.R., for mine ventilation must meet the legislative requirements of local jurisdictions. This paper presents a discussion of these legislative requirements and presents examples of fan equipment designed to meet the requirements. The legislative obligations discussed include four (4) separate requirements, including: ?Technical design requirements ? The Federal Agency for Technical Regulation and Metrology is responsible to issue a GOST R certification declaring conformance to the requirements ?Operational requirements ? A ?License for Application? must be obtained prior to operation ?Explosion risk requirements ? If the area of operation includes potential for explosion a special certificate must be obtained ?Technical condition requirements ? Market segments within the mining industry require special conditions that must be satisfied Examples of fans designed specifically for use in the Russian Federation are also discussed and examples provided. Designs for fan volume flow control will be highlighted.

Aug 1, 2013

By E. Burdukova

Long-chain primary amines are utilized as collectors in potash ore flotation. Krafft temperature of long-chain amines in brine is about 100 °C, and this makes such amines practically insoluble in brine at room temperature. When dodecylamine, melted at 70 °C and dispersed in hydrochloric acid (or acetic acid) aqueous solution, is added to a KCl-NaCl saturated brine at room temperature, the amine precipitates. The experimental results demonstrate that the precipitating amine hydrochloride particles are selectively abstracted by KCl particles, but not by NaCl particles.

Jan 1, 2009

By E. Henderson

"This paper outlines the upgrading of a double-drum 2000 hp cage hoist to provide fully-automatic operation from shaft station control panels. The application utilizes programmable controller technology to provide all necessary functions for movement of personnel and material to 22 locations in a 4000 ft shaft.Various functions involving special design considerations such as ""chairing"", ""jogging"", and three modes of ""multi-level calling service"", are outlined. The use of higher level PLC functions to optimize memory utilization and simulate ""elevator service"" required the addition of a comprehensive fault finding software section to aid in troubleshooting.This paper will deal primarily with the automation portion of the project with references made to other pertinent aspects which were prerequisite to automatic operation. It is not intended to deal with every design detail, but rather to provide an overview of what can be done in the area of automation for those considering such an application. INTRODUCTIONEarly hoisting control systems provided only the essential elements of control, leaving many responsibilities with the operator. With advancements in various areas of technology, electromechanical devices were incorporated to enforce slow-down in end zones, control acceleration rates, monitor safety devices, etc. Brake control systems were supplied to allow for ""single-stick"" operator control, regulated deceleration during emergency brake applications, etc.These additions enhanced the over-all performance but were generally confined to speed and current regulation. Some mechanical devices, such as travelling nut limits, etc.; were used to provide ""position"" control to multiple locations within the shaft. These devices, in conjunction with rather extensive relay control panels, did allow for the establislunent of some automatic cage hoists . The hoists were often limited to service from point ""A"" to point ""B""', involving a limited number of levels due to the complexities of the mechanical interfaces employed. Only limited systematic work sequences were possible . .Programmable Logic Controllers (PLCs) were introduced into industry in the mid-70s and have since gained acceptance in mining applications such as pumping, ventilation, ore handling, etc. This technology, being ""software"" based, allows complexities to reside in the program rather than increasing the number of physical control elements. This has opened the door into hoisting systems for automatic loading and hoisting of ore as well as a means to achieve a comprehensive package of automated cage hoisting functions."

Jan 1, 1989

By J. Kouam

Al-Si-Cu and Al-Si-Mg alloys are widely used in several applications. Although they can be produced near-net-shapes, products made of these alloys very often require some machining. The purpose of this study is to evaluate the machinability of A319 and A356 under TO and T6 conditions. The machinability was assessed using during dry drilling machining process and the machinability indexes used are the chip form, the chip breakability and the cutting forces. It is found that 319 and 356 exhibit different machinability behaviors, especially in the T6-condition in terms of forces requirements, chip breakability and chip segmentation. It is also found that both the microstructure of the workpiece materials and the machining conditions significantly affect the chip formation mechanism, and therefore, the machining parameters could be selected to promote a chip form that is easily manageable in production.

Jan 1, 2011

By M. Fairman

The effect of welding speed on the microstructure of friction stir processed (FSPed) AZ31B-H24 magnesium alloy was studied using light microscopy, image analysis, and microhardness tests. The grain size of the magnesium alloy was observed to increase after FSP from about 3.5 µm in the base alloy to about 8 µm in the stir zone. The aspect ratio decreased from 1.60 to 1.55 towards the center of the stir zone. The changes in the grain size and shape caused the microhardness of the samples to drop significantly across the FSPed region from 75 HV in the base alloy to below 55 HV in the stir zone. Decreasing the welding speed increased the grain size due to a greater input of heat energy. The faster heating rate due to the lower welding speed caused a deeper penetration of the annealing effects of FSP. It was also observed that the annealing effects caused by FSP were less pronounced with increasing distance from the interface between the sample and pin tool shoulder. The Hall-Petch type relationship of the micro-indentation hardness as a function of the grain size was observed to hold true after FSP.

Jan 1, 2007

By James R. Kuipers

Center for Science in Public Participation CSP2 ? Organized in 1997 to provide technical assistance to public interest groups on mining and water quality issues ? 80%of effort devoted to direct support of grassroots groups and tribal governments ? 20% of effort devoted to public-oriented education for public, tribal, state and federal regulators, and for industry ? Board represented by public interest groups, at large citizens, and academia ? Professional staff with experience from mining industry, academia and government ? website: www.csp2.org CSP2 Mission Statement The CENTER for SCIENCE in PUBLIC PARTICIPATION provides training and technical advice to grassroots groups on water pollution and natural resource development issues, especially those related to mining. CSP2 seeks to focus the debate on factual issues, as brought to light by its technical analyses, and whenever possible to seek consensus and win-win solutions. CSP2 also performs policy related work with federal and state regulatory agencies on the implementation of water quality, waste disposal, and mining reclamation regulations.

May 1, 2002