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By Jean Cayouette

"In 1995, Louvicourt Mine started one of the first paste backfill operations in Canada. From 500,000 tonnes in 1995, the annual paste backfill tonnage produced reached 800,000 tonnes in 1999. The maximum throughput of the surface plant (including binders) is 3,50Ot/d with a final density of 75 to 76% solids which gives a slump of 15 to 17cm. Following the start-up of the paste backfill plant, the backfill strength performance levels were well below the pilot plant’s predictions. The introduction of ferrous slag, laboratory tests on various binder ratios with or without additives, and the desliming of the tailings enabled us to optimize the mix and operation costs. Primary and secondary stopes are filled respectively with a paste containing 4.5% and 2% binders consisting of a mixture of 20% cement and 80% ferrous slag. In certain stopes, the binder ratio may vary from 2 to 7%, but always in a ratio of 80/20. Six years after start-up, or 4.5mt of paste backfill later, this paper discusses the present operation and the major changes that have occurred over the years to optimize both the operation and the paste fill quality.INTRODUCTIONLouvicourt Mine is operated by Aur Resources Inc. which owns 30% of the shares. Its partners are Novicourt Inc. (45%, subsidiary of Noranda Inc.) and Teck Corporation (25%). The mine is located in the north-west part of Quebec, about 600 km north of Montreal and about 25 km east of Val d’Or. The mine commenced commercial production in July 1994."

Jan 1, 2002

To simplify programming, image analyzers commonly measure either linear intercepts or the areas of particles and grains to determine liberation based on polished section mounts. However, the concentration of minerals by flotation is based on reagents that interact with the exposed surfaces of the minerals. Thus, it is often perceived that image analyzers should measure the perimeter of the mineral of interest in the ore particles. A comparative liberation study of thirteen samples collected from a flotation plant processing a complex base metal sulfide ore showed that the liberation of the ore minerals determined by area measurements is very similar to the liberation determined by the exposed perimeters. The liberation determined by exposed perimeters is more appropriate only for those cases where the mineral texture is so complex that it is retained in the small particles generated in conventional grinding operations.

Jan 1, 2002

By B M. Guerin

In this paper, some of the constraints to applying bioremediation to the decontamination of polluted soils are introduced. Particularly, attention has been given to those associated with the geology of the polluted site. Areas which require further research have been addressed and indicate that geologists will play a key role, alongside microbial ecologists and engineers, in designing and implementing bioremediation strategies.

Jan 1, 1992

AVERY great profit is derived from removing the gilding and retrieving gold, without destroying the works of silver or other metal. If this method did not exist, the greater part of the gold that is put on certain works would be lost. Even though you might think to scrape it off patiently with a sharp scraper, if it had been drawn with draw-plates, or if it were at the bottom of objects where the scraper could not enter easily, it would be utterly in vain. Therefore, I find that to do this it is necessary to use one of three methods. The first is when it is found on a thin object. Take a large crucible, fill it with mercury, and heat it on a little furnace. When you see that it begins to boil and simmer, put your work in it and stir it around, shaking and rubbing it well in this, and finally rub it with a scratching tool until you see that the mercury has drunk up and absorbed all the gold. Then, having done this, take the said mercury and pass it through an untanned leather purse, and in the bottom of this you will find all the gold like sand. Put this in the bottom of a crucible or in something else over a charcoal fire and evaporate it. If the objects are of a thicker form the gilding is removed from them in another way, by covering them with powdered sulphur and lighting a fire on them. When you see them burning well with the fire all around, beat them in a clean bowl of wood or something else and collect everything that separates with the sulphur from the work; this will be gold in the form of a leaf wherever it has been touched by the fire. The gold is then extracted from this burned sulphur by purifying it in a cupeling hearth with lead. The third method is to touch the gold that you wish to take off the works with an aqua fortis made from saltpeter, rock alum, vitriol, sal ammoniac, and some verdigris.* This acid dissolves and eats the gold by virtue of its corrosive power. Having thus touched the gold with this acid and having saturated the latter with a quantity of gold, put it in a cucurbit and evaporate it over a little furnace as is done with silver, collecting the acid and the spirits if you wish.

Jan 1, 1942

By William C. Laubengayer, Robert R. Godard, Harry Dobroski

A whole mine, computer-controlled communication and monitoring system for both normal and emergency use is installed and operating in the U.S. Steel Robena Mine complex near Uniontown, Pa. Portions of the system, including the coaxial cable and the key underground and surf ace phones, have been operating for over a year and a half. During this time the basic concept has been modified and new line amplifiers with directional switches have been developed to eliminate some problems in implementing the loopback feature. The quality of the audio and the availability of the system have been outstanding. Since early summer almost all subsystems have been completed. The experience with the telephone system itself, the pocket-pager call alert, section wireless radio, hoistphone, television, environmental monitoring, control and monitoring of equipment, voicedownlink/code uplink post disaster communications, post disaster through-the-earth monitoring, and the system center failure diagnostic routines are reviewed.

By B. Anameric, S. Kawatra

Pig iron nuggets, which have similar chemical and physical properties with blast furnace pig iron, were produced by a single step heat treatment of self reducing – fluxing dried greenballs. During this single step heat treatment the transformation of self reducing fluxing dried greenballs into pig iron nuggets did not take place instantaneously. Rather, it was composed of three transformation stages, (1) transformation of self reducing – fluxing dried greenballs into direct reduced iron (DRI), (2) transformation of DRI into transition direct reduced iron (TDRI), and (3) transformation of TDRI into pig iron nuggets. Thus, the objective of this research was to investigate these transformation mechanisms by analyzing the transformation stage products. The transformation stage products were produced at a constant furnace temperature of 1425°C and various furnace residence times. They were characterized according to their microstructure, microhardness and apparent density. The changes in the product’s physical and chemical properties with furnace residence time were utilized in understanding the transformation behavior, the chemical events that took place and the controlling mechanisms. It was determined that the transformations were dictated by the changes in the slag viscosity and wetting properties, and by carbon diffusion into metallized areas.

Jan 1, 2007

The recent mine disasters in Australian coal mines have initiated an introduction of Self-Contained Self-Rescuer (SCSR) as component in the development of new escape strategies for miners. These self-contained self-rescuers are closed circuit, demand sensitive breathing apparatus that make oxygen available to the wearer for a nominal period of time. Their operation is completely independent of the surrounding atmosphere. Once properly donned, the SCSR can assist a miner to escape from an area containing smoke, toxic gases or an oxygen deficient atmosphere. The duration of a typical SCSR is usually taken at the point of complete collapse of the breathing bag which is accompanied by an increase in breathing resistance and inhaled levels of carbon dioxide. Because the oxygen consumption (V02) and the heart rate are correlated, a prediction of V02 and consequently the duration of an SCSR can be made by monitoring the heart rate. Thirty-seven volunteers participated in field simulated escape trials at four underground coal mines. The results from the field trials suggested that oxygen consumption depends on the heart rate, the body weight and exercise rating of the miner. All the volunteers were asked to fill out the questionnaires to evaluate the performance of the units. The miners indicated that they could tolerate the inhaled temperature without any difficulty to breathing resistance. A complete statistical analysis of the field results is also presented.

Jan 1, 1997

By John R. Morgan, Peter Graham

"Onakawana Development Ltd. and Mana/ta Coal Ltd. have completed feasibility studies on a large lignite deposit located in the James Bay lowlands of northeastern Ontario. The mining plan described in this paper would supply coal for approximately a 33-year period with peak production in the early years of approximately 6.5 million tonnes per year then declining to 1.2 million tonnes in year 33. This paper describes the geology, resources, lignite quality, mine planning and related topics. LocationThe Onakawana lignite deposit is located in northeastern Ontario in the James Bay lowlands (Fig. l). The Ontario Northland Railway crosses the property and links it to Moosonee, JOO km further north, and Cochrane 180 km south. The area is crossed by latitude 50° 37', the approximate latitude of Calgary. Toronto lies 800 km south of the study area. History of Development The deposit has been known since the late 1600s when early English settlers extracted limited amounts of lignite for use at Moose Factory. The deposit has undergone sporadic periods of exploration activity in the late 1920s and early 1930s when the Ontario government drilled 116 holes, sunk two exploration shafts and published several technical and economic studies. Interest in the property was reactivated from 1939 to 1945 when the Timiskaming and Northern Ontario Railway Ltd. drilled 182 additional closely spaced holes, excavated a test pit adjacent to the rail line and installed a boiler for testing purposes. In 1965, Alberta Coal Ltd., the predecessor of Manalta Coal Ltd., first became involved. Since then a further 182 holes have been drilled and coied, and the existing test pit reopened for sampling. In 1980, various reassessment studies were launched, including geology, mine engineering, conceptual design and environmental assessment studies. The following discussions have been drawn extensively from these reports."

Jan 1, 1985

By W. P. Roux

Owing to decreasing high-grade ore reserves, there is a need for better understanding of the jigging process to improve the recovery efficiency of finer, lower grade material. The use of positron emission particle tracking (PEPT) was examined as a technique to study the motion of iron ore particles inside a laboratory batch jig. PEPT is a non-invasive method that can provide three-dimensional kinetic data on a particle in laboratory-scale processing units and has been successfully used to study mills, hydrocyclones, and flotation. Experiments were conducted to determine whether PEPT would be a viable technique to study iron ore jigging and what valuable information could be obtained. The results indicated that detailed information on the stratification rate of a particle could be obtained, with adequate resolution to track the particle?s movement through an individual jig pulse.

Jan 1, 2014

By Y. Mudryk, D. Paudyal, K. A. Gschneidner, V. K. Pecharsky, M. Khan

"Rare earth intermetallic compounds are utilized commercially as magnetic and battery materials, electron gun electrodes, etc. Several of these intermetallics will be briefly discussed. There are many other rare earth intermetallic compounds which are not utilized industrially but have unusual properties which are of fundamental interest and may have future technological applications. Several of these materials are discussed as well.INTRODUCTIONTens of thousands of rare earth intermetallic compounds exist, but physical properties (primarily their magnetic behaviors), other than their crystal structures have been measured for only a small percentage of these materials. Among these are the commercially important compounds: Nd2Fe14B, and the SmCo5 – Sm2Co17 family – well known high strength permanent magnets; (Tb0.3Dy0.7)Fe2, Terfenol-D, a giant magnetostrictive material; LaNi5Hx a critical component of the rechargeable Ni metal hydride batteries; and LaB6 an electron emitter. There are, however, many other intermetallic compounds which are not utilized industrially, but none-the-less, exhibit interesting, and sometimes, exotic physical properties which are of fundamental interest and may have some future technological significance. These include: the giant magnetocaloric effect compounds Gd5Si2Ge2 and La(Fe13-xSix)Hy; the RCu and RAg families of ductile intermetallics; the mixed intra-lanthanide (R,R')Al2 compounds in which magnetic transitions disappear and reappear as one R is substituted for by R'; and GdNi which exhibits large dilations along two crystallographic directions and a larger contraction in the third direction at the Curie temperature resulting in zero volume change as GdNi orders magnetically via a second order phase transition.COMMERCIALLY IMPORTANT INTERMETALLICSNdFeB Permanent MagnetsThe Nd2Fe14B permanent magnets were discovered in 1984 independently in the USA and Japan. It is a ferromagnet and with proper heat treatment and processing Nd2Fe14B is the strongest near room temperature permanent magnetic material known today. This intermetallic compound is utilized as a permanent magnet in many applications, such as electric motors (e.g. the modern automobile contains up to 35 electric motors), spindles for computer hard disc drives, microphones and speaker magnets for cell phones and other audio equipment, direct drive wind turbines, actuators, and Magnetic Resonance Imaging (MRI) units. There are two kinds of NdFeB permanent magnets – bonded and sintered. The bonded magnets have a lower magnetic strength than the sintered magnet. The highest strength magnets are obtained by small substitutions of Dy (up to a maximum of 10%) for Nd, because Dy can significantly increase the coercivity and thus the energy product (a measure of the magnetic strength or hardness). The bonded magnets account for about 12% of the NdFeB market (~82 metric kt per year, containing ~20 kt/a of Nd). The NdFeB permanent magnet market is growing at a rate of about 15% per year. (Burzo & Kirchmayr, 1989; Kobayashi & Hirosawa, 2001; Coey, 2011)."

Jan 1, 2012

By A. C. Watts

The question of disposition of the slack and dust so troublesome to coal mine operators of the West has been divided by your committee chairman into three heads, viz: The preparation and transportation of fine and powdered coal. The developments along the line of low heat carbonization. The uses to which fine and pulverized coal have been put. The development of low heat carbonization has been assigned to me. This is really not a part of the subject but as it has a most important bearing on the future use of coal, I presume the chairman thought best to include it. An English committee on smoke abatement makes the statement that the burning of raw coal is "dirty, wasteful and unscientific". I will go a step further and characterize it as an "economic crime." It has been predicted by eminent scientific men that eventually no raw coal will be burned for heat or power purposes. All this will take time, experimentation and large expenditure, but it will surely come. The question of disposition of slack and dust so troublesome to coal and utilization of its by-products has been retarded by the abundance and cheapness of the raw coal, and by the abundance of suitable coking coals for metallurgical purposes. But necessity is surely, if slowly, demanding that the enormous waste ensuing from the burning of raw coal for heat and power must cease. For instance, smoke abatement investigations in Manchester, England, showed that the increased cost of household washing was about $1,250,000 per year due to smoke and soot. It is estimated that in London 200 tons of soot and smoke particles are suspended in the atmosphere over that city during dense fogs and that much more than this is emitted from the chimneys each winter day during the forenoon. As an example of what benefits a smokeless fuel gives, it is cited that in the mill town of Shaw, England, the burning of smokeless fuels in the factories has reduced the so-called fogs by about 80%. Necessity, caused by the war led Germany into the field of low tem¬perature carbonization because of the shortage of motor fuel and lubricating

Jan 1, 1922

Forecasting, particularly when applied to meaningful issues, is known irreverently as 'futurology'. There is quite a range of opinion ext.ant in the world when mineral resources are looked at. The opinions range from the doomsday view that there will be acute shortages of all essential commodities, to the optimistic outlook that new 'discoveries will prevent any possibility of shortages. The environment is, as yet, only studied locally and quite parochially; surprisingly there is little integration when considering the spatial atmosphere, the seas in depth and the earth's crust.

Jan 1, 1981

By J. Engels

CODELCO is considering the implementation of high-density tailings management at the Chuquicamata mine in northern Chile for its long term disposal plan. To achieve this, CODELCO commissioned the design, construction, and operation of a 70 t/d pilot plant, fed by existing tailings. The testing programme was completed in May 2011, and consisted of laboratory rheological and characterization assessments, pipe loop testing, beaching trials, and analyses of deposition behaviour for solid contents ranging from 57?68% (w/w). This paper describes the characteristics of the pilot plant, the testing programme, the beach trial analyses, and the resulting beach profile predictions based on the stream power theory. CODELCO also used other predictive beach slope methods, such as the equilibrium slope concept, which are not discussed in this paper. The final beach profile for design will be selected after an expert analysis of all methods has been completed.

Jan 1, 2012

By D. L. Langhans

Platinum-group metal (PGM) converter matte from the Stillwater Complex, MT, was subjected to chemical and biological leaching in an effort to upgrade the matte by decreasing the Cu and Ni content. Copper and NL extractions were optimized in a two-stage chemical leach. Atmospheric pressure sulfuric acid leaching removed over 90 pct of the Ni and Fe in the first stage, while 95 to 98 pct of the Cu was removed is the second stage using an acidified cupric chloride leach. This two-stage leach, followed by an elemental sulfur removal step, decreased the weight of the matte by 90 pct. The combined Cu and Ni content was reduced from 65 pct to less than 20 pct, while the PGM content was increased from less than 2 pct to 26 pct. Biological oxidation using Thiobacillus ferrooxidans also proved to be an effective method for removing Cu and Ni. Over 90 pct of the sulfide was oxidized and 99 pct of the Cu and Ni were solubilized, leading to a 60 pct reduction of sample mass during the 17 week bio-oxidation of the Stillwater converter matte. The final residue, after removal of jarosite that accumulated during bio-oxidation, contained less than 3 pct combined Cu and Ni and 6 pct MM.

Jan 1, 1993

By Devin Burns, Saima Ghazal, Michael Owusu-Tweneboah, Kwame Awuah-Offei

Trust in AI systems and the nature and amount of information about the system can influence decision-making. It is, therefore, crucial to understand how AI-powered monitoring systems (e.g., gas monitoring systems) influence miners’ trust and decision-making in emergency evacuation. This work focused on measuring the differences between how participants respond to a simulated underground mine emergency evacuation situation when warnings are represented as coming from a human or AI-based monitoring system. We also manipulated the amount of information participants received about the system, yielding a 2×2 between-participants survey design. The participants received an alert message about rising gas levels in a mine and provided a response on how they would react and reported their perceived safety. We also asked questions to assess their trust in, preference for AI over human-based gas monitoring systems, and whether they are willing to delegate the duties of underground gas monitoring to AI systems. The experiment results show the amount of information had a significant influence on miners’ trust and decision-making. The safety perception of participants based on age, number of children and ethnicity was significantly different from one category to another. This work provides valuable insights as the mining industry deploys AI systems to aid mine safety.

Feb 1, 2025

By J. Bruce Wagner, Roger L. Levin

Integrated forms of two solutions of Fick's second law for the movement of a plane interface through a sample of wustite, and for diffusion into a semi-infinite slab of wustite, are shown to yield nearly identical values of the chemical diffusion coeffcients of cation vacancies in wustite, over the temperature range 900° to 1100°C. The chemical diffusion coefficients, the values of D obtained for the propagation of a concentration gradient through samples of undoped and doped wustite, are obtained from the equations It is becoming increasingly important in metallurgical practices to understand the role of the chemical diffusion coefficient, i.e., the diffusion coefficient of a species across a concentration gradient. During the first stages of sintering, one of the mechanisms by which the bonds between neighboring particles develop is by volume or bulk diffusion. This diffusion coefficient as deter- where ?m is the weight change at any time t, ?W is the total weight change at t =8, A is the area of the specimen, and AC is the total change in the cation concentration after the establishment of equilibrium, as determined by reduction experiments in different carbon monoxide -carbon dioxide mixtures within the limits of existence of the single-phase field. mined from the standard equations for volume diffusion during sintering is actually a chemical diffusion coefficient, and it has been observed to be many times larger than the self-diffusion coefficient as determined on the same materials by experiments using radioactive tracer techniques. Kuczyn-ski1 has noted that, if the controlling mechanism of sintering of A12O3 in an oxidizing atmosphere is the diffusion of oxygen, then this diffusion coefficient as measured from sintering rates is about 2.2 x 104 higher than the self-diffusion measurements obtained by tracer techniques. He has also reported the diffusion coefficient obtained from the rate of sintering of Fe2O3 powder to be about 10 6 times faster than the self-diffusion coefficient of

Jan 1, 1965

By Peter Chmara

The measurement of dust concentration in Ontario mines since 1926 has been accomplished by konimetry, based on South African experience and methods. The introduction of a voluntary program of semi-annual surveys of air conditions at all operations throughout Ontario mines created a need for an instrument that would assess konimeter spots rapidly and accurately. The development of the Electronic Scanner, it is felt, answers this need. A program whereby all konimeter spot samples taken at Ontario mines will be counted at the MAP AO field offices in North Bay is described.

Jan 1, 1969

By Humberto García Uculmana

El presente texto es un análisis realizado en la corporation Centromin de Cerro de Pasco que señala las características del material pirítico y su asociación con la plata. El estudio a través de diversas pruebas de laboratorio determina los esquemas semi-industriales económicos para la recuperación de plata y otros valores a partir de los minerales refractarios. En este sentido, Centromin dispone de tecnología para beneficiar esta fuente convencional primaria de plata, donde utiliza el proceso de lixiviación ácido clorurante en pilas para producir aproximadamente 500 mil onzas de plata a un costo menos operativo.

Nov 24, 1986

By Derek Ettie

"In the Hydrometallurgical processes, the presence of the so-called "crud" is a constant challenge in solvent extraction. Crud is a stable emulsion which forms along the interface between the aqueous and organic phase. The spread is influenced by the following parameters: first, wind blows the dust and impurities into the open sedimentation tanks. Second, the undissolved solids such as sand transported in the PLS causing problems in conjunction with incorrect agitator design.The crud fraction can decisively impact the efficiency of the hydrometallurgical extraction because the phase interface can constitute a large fraction and the sedimentation tanks cannot react flexibly to it. In the downstream process of the series-connected sedimentation tanks, they are thus all contaminated with crud. At the same time, the necessary mass transport is significantly impeded at the phase boundary between organic phase and aqueous phase due to the crud formation.The transfer of the organic phase into the electrolysis cell can result in a "burnout" of the cathode. The carryover of this electrolyte into the extraction can cause problems with the pH regulation. The carry-over of the organic components into the raffinate also leads to contamination of the leaching circuit. The continuous treatment of the crud with a 3-phase decanter centrifuge is extremely effective in combating this problem. This technology splits all three phases from each other and they are consequently continuously separated. All subsequent process steps exhibit a stable, uniform effectiveness. The main advantage for the customer is that fluctuations in the process are eliminated and the organic phase can be recirculated back to the extraction. The recycling of the solvent alone justifies the investment in less than 6 months as examples from South Africa and Chile show.To operate solvent recovery in daily operation fully automated online at the optimum limit, the decanter centrifuge is equipped with a concentration-dependent pond adjustment called DControl® by this means, we can guarantee our customers the maximum possible solvent recovery and minimize the solvent costs in this process step. This system is presented in detail in this paper."

Jan 1, 2014

By G. E. McElroy

"The development of certain mines in the East Tintic mining district, Utah, has been hindered considerably by the presence in the rock strata of heavy irrespirable gases which at times flood the lowest working places, as well as by abnormally high rock temperatures in the lower horizons. A study of these features was completed in the spring of this year, and the information obtained is summarized here.Heavy gases.Only four mines have been affected to date by the presence of heavy gas, and only one of these is producing lead-silver ores in quantity. These four embrace a territory extending about three miles north and south and about two miles east and west, while both within and fringing on this territory are a number of prospects which have not been affected.Thus far no fatalities have resulted from gas inflows, but a number of men have been temporarily overcome, and a few have had narrow escapes from death by suffocation. That the record is not more serious is mainly due to the fact that the gas inflow, as a rule, is relatively slow, mining operations have been quite carefully conducted, and the presence and extent of a gas inflow can be easily determined by its extinguishing action on the flame of miners' lights.When first encountered, about 1910, gas inflows occasioned much lost time. In some months the lost time averaged as much as ten days, while one mine cites for a certain month a maximum of 26 days lost out of a possible 28 working days. With improvements in mechanical ventilation and the passing of time, interference with work from the presence of gas has gradually lessened. During the last few winters, the main trouble has been with the mines being flooded with gas overnight when fans were not operated, although men have been driven out of the lowest development openings several times each winter with fans operating. At present, the main danger is in the lowest development openings having only one exit, wherein men might be trapped and possibly suffocated during an unusual and extremely rapid inflow of gas, or during an ordinary inflow, should the one source of power for the fan be disabled."

Aug 1, 1921