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By J. R. MacDonald

MINING literature contains very few descriptions of operations producing as little as 25 to 30 tons of ore per day. The purpose of this paper is to discuss the gradual development of a mining method for such a small-scale operation at the No. 2 mine of Central Patricia Gold Mines, Limited, and in doing so to review several systems of stoping applicable to narrow ve1ns. MAIN ECONOMIC FACTORS TO BE CONSIDERED (1) Overhead.-The outstanding feature of most mines operating on a single narrow vein is chat of small daily tonnage. The reason for this low output can be readily understood. The strictly limited ore-reserves present a condition unfavourable for a policy of large initial expenditures, with the result that the capacity of the plant provided must be governed by the? amount of ore in sight at the time when mill construction is planned. This is immediately reflected in the cost per ton, there being relatively few tons over which to distributed the more or less static charges, such as hoisting, heating, supervision, administration, pre-production expenses, and other write-offs. (2) Development.-In mining this type of orebody, the main factor contributing to high costs is unquestionably the small tonnage of ore made available by a given amount of development. Thus, for example, from the data tabulated below it can be seen chat, assuming a 12-in. vein and a drifting cost of $9.00 per foot, the development charge for this item alone would be 71 cents per ton. Add to this the charges for raising, cross-cutting, shaft-sinking, and pumping, besides charges arising from development in waste, and the figure will be very considerably higher than 71 cents.

Jan 1, 1941

By John Rowson, Caitlin Brown, Kebbi Hughes, Joseph Esslifie-Dughan

The McClean Lake mill in northern Saskatchewan, Canada, is operated by Orano Canada Inc. and has been in production for the last 20 years. The tailings preparation process at the mill has been designed with decommissioning in mind, to produce tailings that are geochemically stable over the long-term within the site’s tailings management facility. Twenty years of study have contributed to a detailed understanding of geochemical and geotechnical properties of the McClean Lake tailings. Validation of the tailings properties has occurred through in-situ sampling campaigns conducted initially every year, and later every five years. Each sampling campaign has applied the same rigorous sampling procedure to provide data with useful correlations year over year. Each campaign result compares elements such as the inherent variability of the tailings, consolidation of the tailings and variations in the tailings placement methods. We will discuss lessons learned from seven sampling campaigns over 20 years and present data to show the reliable tracking of geochemical evolution of the in-situ tailings over time; providing opportunities for continuous improvements.

Jan 1, 2020

By R. A. L. Drew, F. Jalilian, M. Jahazi

Joining of superalloy Inconel 61 7 with a foil interlayer using transient liquid phase bonding (TLP) technique was studied. Inconel 617 is a solid solution, Ni - Cr - Co- Mo alloy with an exceptional composition of high temperature strength, oxidation, carburization resistance and thermal stability. In this investigation, two bonding temperatures, 1065°C and 1150°C, and two interlayer thicknesses with joining times varying from 5 minutes to 24 hours were employed. Experiments were carried out using nickel base interlayer (A WS BNi-3) with boron as the melting point depressant (MPD) element. Joints were characterized using optical microscopy, SEM, FEG-SEM, EBSD, XRD and microhardness. The results indicated that the rate of elimination of the liquid phase with increasing the bonding temperature, holding time and decreasing the thickness of the interlayer increased. The main precipitates in the diffusion layer had platelike and blocky morphologies for both bonding temperatures and all holding times.

Jan 1, 2006

By M. Oliazadeh, A. Vazirizadeh

"The inclusion of small amounts of silicon, phosphorus and sulphur in iron ores or concentrates can have a profound effect on the steel making process and thus on the final iron and steel products. In nature however, it is inevitable that iron deposits contain unwanted elements. Each element has its own distinct effect on the final steel product. The effect of high silicon is the formation of gray iron. Phosphorus mainly increases hardness and strength, lowers solidus temperature and increases fluidity and cold shortness. Finally sulphur contamination causes cracks in the iron texture when smelting and forms white iron when casting. Overall, the acceptable level of phosphorus, sulphur and silica in the iron concentrate should be less than 0.04%, 0.15 % and 1.5 % respectively.Scarcity of high grade iron ores necessitates using lower grade ores with higher amounts of impurities. The purpose of iron concentrators is to increase iron grades to an appropriate level suitable for steel making as well as removing impurities. Although many impurities can be traced in the ore, the most predominant impurities are limited to one or two elements. In this paper the beneficiation methods for removing SiO2, P and S are presented, including flotation, and the parameters that need to be considered in the design of beneficiation plants are discussed. Finally industrial cases are discussed along with their metallurgical performance.INTRODUCTIONIn metal sector, value of iron ores and concentrates is determined by iron percentage as well ascontent of:• Useful elements (Mn, Ni, Cr, V, Ti): natural alloying elements in steel• Deleterious impurities (S, P, As, Zn, Pb, K, Na): impair metal properties or complicate operational process in blast furnace• Fluxing components (Si, Ca, Mg,, Al)Sulphur and copper result in red-short, phosphorus is the cause of cold brittleness and arsenic and copper decrease welding characteristics. Sulphur should not exceed 0.15 in commercial ore. Acceptable sulphur content in ores and concentrates for producing sinter and pellets is 0.6%max, as sintering and heat hardening of pellets remove sulphur 60-90%. Phosphorous content in ores, sinter and pellets is limited to 0.07%-0.15%. 0.00.1% As max, 0.1-0.2% Zn max and up to 0.2% Cu are allowed in iron-ore part of the blast furnace burden for the production of standard conversion pig iron. Slag-forming components are divided into basic oxides (Ca, Mg) and acidic (Si, Al). Higher ratios of basic to acidic oxides are preferred since this reduces raw fluxing material."

Jan 1, 2016

By C. Han, S. J. Zhou, Y. B. Shen, D. Z. Wei, P. Fang

"Collecting property of two hydroxamic acid collectors have different type of nonpolar structure to hemimorphite has been comparatively studied via monomineral flotation test, and the reason causes different collecting performance has been discussed from the view of relationship between molecular structure and collecting property. The flotation tests results show that C5-9 hydroxamic acid has an unbranched linear alkyl nonpolar group shows better collecting property to hemimorphite than cyclohexyl hydroxamic acid which has a naphthenic nonpolar group. FTIR detecting results show that the adsorption type of collector adsorbed on hemimorphite surface is chemical adsorption. Calculation results of polar group’s geometric structure parameters, polar group’s electron density distribution, octanol-water partition coefficient (logP) and molecular frontier orbital energy show that the key factor caused different collecting property of two collectors to hemimorphite is the logP; unbranched linear alkyl nonpolar group is more conducive than naphthenic nonpolar group to make hemimorphite particle more hydrophobic.INTRODUCTIONZinc-bearing mineral recovered from lead-zinc ores is the main source that people can obtain zinc resource from nature. However, natural sulfide ores are currently getting depleted steadily for the primary zinc source. In order to satisfy the future demand of zinc resource, there is an obvious recognition that the recovery of zinc oxidized minerals from the ores is a crucial alternative (Hosseini & Forssberg, 2007; Navidi Kashani & Rashchi, 2008).But the fact that can’t be ignored is the flotation of zinc oxidized minerals is much more difficult than that of zinc sulfide minerals, which is mainly due to the flotation characteristics of these zinc oxidized minerals such as lower selectivity and higher reagent consumption, as well as complex and variety of lead-zinc ores. Presently, there have been many various beneficiation technologies used for recovering zinc oxidized minerals and dealing with ores for recovering metallic zinc such as flotation and hydrometallurgy (Abkhoshk, Jorjani, Al-Harahsheh, Rashchi, & Naazeri, 2014; Önal et al., 2005). But from an overall perspective, flotation is the most common method used for the beneficiation of zinc oxidized minerals, and there have been extensive investigations conducted on the flotation of zinc oxide ores (Ejtemaei, Gharabaghi, & Irannajad, 2014). Until now, the most well-known method used commercially for the flotation of zinc oxidized minerals is sulfidization with sodium sulfide and flotation with a cationic collector of amines containing from 8 to 18 carbon atoms. However, a major problem for this method is the large amount of fines and slime results in the increase of reagent consumption and promotes the phenomenon of slime-coating. For preclude this negative effect, the de-sliming and processing optimization is indispensible (Peres, Borges, & Galery, 1994; Salum, de Araujo, & Peres, 1992)."

Jan 1, 2016

By J. Mirza, E. Nicol, J. Lipkowski

Gold passivation in thiosulfate leaching media is a major barrier to its implementation. Addition of Cu (II) into the leaching solution has shown to aid in gold dissolution, but the mechanism by which it acts, and its role in the passive layer, remains unknown. Surface Enhanced Raman Spectroscopy (SERS), in tandem with linear sweep voltammetry, were employed to determine the dependence of leaching currents on mass transport and for fingerprint identification of sulfur species on the surface of gold. SERS leaching experiments were performed using gold nanorod electrodes that showed increased stability compared to other SERS active surfaces.

Jan 1, 2011

By J. B. Rubenstein

This work demonstrates the feasibility of using confocal surface profilometry to measure and characterize wear of graphite anode surfaces. This method was tested using anode samples that were electrolyzed for 24 hours in a laboratory-scale magnesium cell with a high oxide molten salt electrolyte. The oxide produced accelerated wear on anodes designed for low oxide electrolytes. Contour maps, which are effective at displaying non-uniform wear, and total graphite consumption values were generated from the collected surface coordinates. Along with both qualitative and quantitative analysis capabilities, this measurement system was shown to have a fine resolution and a low detection limit.

Jan 1, 2004

By K. Hawboldt, J. E. Halfyard, C. Bottaro

The removal of sulfur from leach residues has been practised in the zinc industry using a combination of flotation and hot melt filtration. The process is highly dependent on the nature of the concentrate and the subsequent residue. When the mineral constituency of the residue alters, the process can encounter significant operational challenges. An alternate method of converting elemental sulfur to water-soluble polysulfides was applied to leach residue from Vale's nickel demonstration plant in Argentia, Newfoundland. Reaction parameters, sulfur purity and other key indicators are discussed as is the potential commercial application.

Jan 1, 2011

By P. J. Finnis

This paper describes the use of wire rope on open-pit mining equipment, giving specifications and examples of the performance achieved. Installation methods are also discussed, making the paper of considerable practical use to mine operators.

Jan 1, 1973

By F. G. Smith

Abstract Laboratory methods are now in use whereby the temperature and pressure during the crystallization of hydrothermal minerals can be determined. The techniques include the use of the decrepitation method of studying liquid inclusions, and electrical measurements of pyrite. The determinations are sufficiently accurate that the data can be used in solving a variety of ore deposition problems. Within the last year, several new laboratory techniques have been developed in the Geochemical Laboratory of the Department of Geological Sciences, University of Toronto. The results of several tests of ore by these methods have proved to be useful in treating some problems which previously were considered unsolvable. It is now possible to determine the temperature of deposition of most of the minerals in a hydrothermal ore deposit, also the depth below the surface during deposition. Measurements can also be made of the reopening history of a complex ore. The temperature-pressure determinations depend upon the fact that minerals deposited from a hydrothermal solution always trap a small amount of the solution at the time of crystallization. The solution, being predominantly composed of water, has a density which depends upon the temperature and the pressure prevailing during crystallization. After ore deposition is complete, erosion and isostatic uplift finally exhumes the vein. During this slow fall in temperature and pressure, the solution contracts and a gas bubble appears. If the trapped solution in the mineral is examined, the gas-liquid ratio records the density of the solution at the time the mineral was deposited (except for a slight change in the volume of the mineral). The thermal expansion and compressibility of water and water solutions are known to a sufficient degree that, if the gas /liquid ratio can be determined, the temperature-pressure relations during deposition can be calculated.

Jan 1, 1949

By Zhibao Li, Lanmu Zeng

The behavior of dicalcium silicate in NaOH-NaAl(OH)4-Na2CO3 solution is of significance for controlling the silica level in the production of alumina via the sintering process. Dicalcium silicate samples were obtained through a twostep approach: coprecipitation of calcium and silicate from CaCl2-Na2SiO3-NaOH solutions; and calcination of the hydrated precursor at 1200°C for 4 hours. The optimization of the synthesis parameters including temperature, solution concentrations and aging time was also investigated. Xray diffraction (XRD) and chemical analysis show that the calcined solids include dicalcium silicate with trace amounts of wollastonite. The solubility of the synthesized dicalcium silicate in HCl, NaOH, mixed NaOH-NaAl(OH)4 and NaOH-NaAl(OH)4-Na2CO3 solutions was determined. It was found that the solubility increases with increasing HCl and NaOH concentration. The effect of temperature on the solubility in HCl solutions is limited, but the solubility decreases with increasing temperature in NaOH solutions. The solubility of dicalcium silicate in NaOH-NaAl(OH)4 and NaOH-NaAl(OH)4-Na2CO3 solutions was shown to increase with increased temperature, Al(OH)3 and Na2CO3 concentration. The BromleyZemaitis model for the aqueous electrolyte system was selected to predict the solubility of dicalcium silicate. The model’s predictions yielded certain success compared with experimental solubility data.

Jan 1, 2014

By H. J. Ni, M. Y. Huang, S. W. Chen

The effects of several fluxes on purification, microstructures and properties of A00 aluminium have been studied. The experimental results and analyses indicate that many cracks and large porosities exist in the surface film above the melt purified by C2Cl6 and that the film is floe and mostly composed of AhO3 and pure aluminum, which carries many carbon particles and AlCh not fully volatilized. And then over 50% of the all-melting residue is pure aluminum, which is one of the major reasons for high melting loss. Moreover, because of a mass of gas bubbles and a state of seethe, there exist many inclusions which size is under l0µm in the microstructure of A00 aluminum purified with C2Cl6 or fluxes containing C2Cl6- With this purifying method, the aluminum crystal grains are extended along the radius that was observed firstly and the average crystal size of A00 aluminum are about 100µm~150µm. In addition, small size inclusions have little affected on tensile strength and micro inclusions under l0µm have little affected on elongation.

Jan 1, 2006

By A. Singh

"Flotation of fine (< 10 µm) minerals is a challenge exacerbated by the emerging practice of fine grinding flotation feed to better liberate targeted minerals; however, the ability of conventional flotation cells to float liberated fines remains questionable. The Gold Ore solution using Mach reactors was tested at Mintek, South Africa, and showed an ~180% increase in the Kelsall kfast factor, a projected recovery improvement of 4% for the Mach-reactor case, and final concentrate grade twice that of conventional flotation. Theory, pilot plant results, and key aspects of plant design, supplemented by operational plant observations after commissioning, are discussed.RÉSUMÉ Le procédé de flottation de minerais fins (< 10 µm) pose de grandes difficultés, lesquelles sont aggravées par la pratique émergente de l’alimentation du circuit de flottation avec des mailles de broyage très fines pour mieux libérer les minéraux ciblés ; la capacité des cellules de flottation classiques à flotter les fines de minerais libérées reste cependant discutable. La solution proposée par la société Gold Ore, qui utilise des réacteurs Mach, a été testée à Mintek, en Afrique du Sud ; elle affichait une augmentation d’environ 180 % du facteur kfast développé par M. Kelsall dans son modèle de flottation, une amélioration prévue de la récupération de 4 % dans le cas du réacteur Mach, et une teneur finale des concentrés deux fois plus importante que celle obtenue avec la flottation classique. Sont débattus dans cet article la théorie, les résultats générés par l’usine pilote ainsi que les principaux aspects de la conception de l’usine complétés par des observations relatives à l’usine en activité après sa mise en service."

Jan 1, 2018

By R. A. Rabnett, G. Paget, Patrick Walsh

"Tumbler Ridge, Canada&apos;s newest resource community, has been developed differently than have been other resource communities.Since its conceptualization, emphasis has been placed on the establishment of a traditional municipal government at early a stage as possible.Planning f or the community goes back to 1977. By then, extensive study by provincial agencies had shown a new resource town would be required to exploit north east coal. The Ministry of Municipal Affairs, in conjunction with a consultant named R.A. Rabnett began the extensive Tumbler Ridge conceptual plan.The results of the conceptual plan are evident in the organizational and planning goals of Tumbler Ridge. In every aspect from the election of officials to some financial matters, the town functions as a normal municipality. With the resource companies of the North East Coal Development within its municipal boundaries. Tumbler Ridge has been able to debenture its capital projects against its municipal tax base.The town&apos;s ability to function as a normal municipality is enhanced by its control over Crown land it has purchased from the province. This gives it further control over the development of the community and helps in establishing agreements with the resource companies and the provincial government to ensure that housing and service needs are met. While resource company representatives sit on certain municipal committees, their roles are advisory in nature.The community continues to move toward full municipal status and will have a fully elected Council by 1986.BackgroundPlanning for the development of northeast British Columbia coal resources began in 1976 under the aegis of the provincial Cabinet Committee on Coal Development. A series of subcommittees were established including a Townsite/Community Development subcommittee. The Ministry of Municipal Affairs chaired this subcommittee and continued as the lead agency for the provincial settlement planning effort over the period 1976 to 1981."

Jan 1, 1983

By M. Rafieazad, P. Fathi, X. Duan, M. Mohammadi, A. M. Nasiri

"Direct metal laser sintering (DMLS) is a metal additive manufacturing technology that creates highly complex components by fusing metal powder into a solid part. In this study, the impact of surface roughness on corrosion resistivity of AlSi10Mg_200C alloy manufactured through DMLS was investigated. The as-printed DMLS-AlSi10Mg _200C alloy was subjected to various surface finishing processes including grinding and sandblasting. The corrosion performance of the surfaces was then evaluated using potentiodynamic polarization testing and electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution to mimic seawater environment. Surface characterization and corrosion morphology of the samples were assessed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) spectroscopy. The results of this study show that the surface finishing process and the resultant surface roughness has a significant impact on the corrosion resistivity of the DMLS-AlSi10Mg_200C alloy in the seawater environment.INTRODUCTION Direct Metal Laser Sintering (DMLS), also known as Selective Laser Melting (SLM) (Sames, List, Pannala, Dehoff, & Babu, 2016), Laser Beam Melting (LBM), or Laser Metal Fusion (LMF) (Herzog, Seyda, Wycisk, & Emmelmann, 2016), is an additive manufacturing process that utilizes a precise, high-power laser to micro-join powdered metals and alloys layer by layer to form almost fully dense and functional components in three dimensions from the 3D computer-aided design (CAD) data. Complex geometries not possible with conventional manufacturing processes can be readily manufactured with high accuracy using the DMLS process with no need to time-consuming tooling."

Jan 1, 2018

By Peter S. Jack

"IntroductionTHE ORES treated at the concentrator of the Britannia Mining and Smelting Company, Limited, Britannia Beach, B.C., have always contained some lead, but it was not until 1950 that the combination of lead headings and lead price was such that recovery of this metal at Britannia became worthwhile. In that year, with the mining of a new orebody, the lead in the mill feed was raised from 0.07 per cent to 0.15 per cent. Chalcopyrite, sphalerite, and pyrite concentrates are produced by flotation at Britannia, •and 95 per cent of the lead in the mill feed reports with the chalcopyrite concentrate, so that the rise in lead headings was reflected almost wholly in the lead content of the copper concentrate. In 1950, investigation was started to determine if some of this lead could be recovered economically."

Jan 1, 1953

By Thomas Hauquin, Olivier Deck, Yann Gunzburger

"In this study, 2D numerical modeling of a room-and-pillar mine is conducted along with the calculation of all terms of the mechanical energy balance. Simulations of different geometrical and geomechanical configurations are performed in order to investigate the conditions that favor a high seismic energy release (instability) during the excavation (removal) of one single pillar. At first, classical stressstrain simulations enable us to estimate the elastic and quasi-static response of the mine. Then, owing to the implementation of new functions in the modeling code, the seismic energy released when the pillar is removed is calculated. The obtained values are found to be in agreement with those calculated analytically using a modified energy balance based on the works by Cook (1967) and Salamon (1984).It is shown that the mine’s proneness to release large amounts of seismic energy, after sudden removal of one single pillar, mainly depends on three parameters: the initial extraction ratio of the mine, the depth of the exploited seam and the Young’s modulus of the surrounding rock mass compared to that of the ore. Moreover, it is pointed out that the magnitude of the seismic energy can be greater than that of the stored elastic energy, meaning that the dynamic (seismic) transient stresses should not be neglected when compared to the quasi-static stresses, particularly when trying to prevent the risk of rockburst and collapse in underground mines."

Jan 1, 2015

"The Pierre Beauchemin Mine attained commercial production in January 1989, and went on to produce 23 968 ounces of gold for the year, 3% higher than forecast. Underground development was accelerated to prepare the way for the production of an estimated 40 000 ounces in 1989.IntroductionThe Pierre Beauchemin Mine is located nine miles west of the city of Rouyn-Noranda (Fig. I).As a result of the amalgamation with Sullivan Mines in October 1987, the mine is now entirely owned by Cambior Inc.The Eldrich deposit was discovered in 1953and began production in 1955, closing in 1962 following the decrease in gold prices and the simultaneous decrease in silica content in the ore, which was sold to the Noranda smelter for flux. A total of 717 000 tons grading 0.14 oz Au/t were produced during this period.From July 1984 to October 1987, an underground exploration program was carried out by Sullivan on the Eldrich mining concession and the nearby Flavel property. The first phase of the program included reinstallation of surface facilities and dewatering of the Eldrich Mine. Following the completion of the first phase, extensive exploration was carried out, including a major program of diamond drilling. It was then decided to deepen the shaft to a depth of 1800 ft to access a new zone called the No.5 Zone .Following the amalgamation with Sullivan in October 1987, Cambior assumed the role of operator for the project, and continued the shaft deepening work that had already been started. A feasibility study was completed in April 1988 and the Cambior board of directors approved a production decision for the Eldrich-Flavel project.The preproduction program extended from May to December 1988 and was aimed at preparing the stopes in the upper part of the mine and at developing the mine infrastructure at the bottom of the mine.The mine was officially opened in August 1988. Cambior renamed the project the Pierre Beauchemin Mine in recognition of Pierre Beauchemin&apos;s pioneer-work."

Jan 1, 1990

By Michael Farley, Paul Dufour

"Relationships, Partnerships,Marriages (RPM)RPM has a nice musical ring to it, but it is in fact synonymous with science and technology, university-government -corporate links and the more genera l issue of university roles in technology development. Pick up any report on one of these issues, and chances are that you will find one of these key words in the title. Play it, and you will find that the revolutions per minute are increasing. It is difficult to keep track of the wide variety of institutional experiments now developing in Canadian universities in attempts to marry science and research with technology commercialization and technology transfer.Why is the role of Canadian universities in this matter important? There are at least five good reasons:1. It is important because these knowledge institutions are producer s of scientific research, a major component of technology. Today the gap between the two is rapidly shrinking.2. It &apos; is important because Canadian industry is turning to universities for tech no logy development and new knowledge. Figure 1 shows that universities are becoming an important source of technology available to Canadian firm s; more important in fact than government. Figure 2 illustrates this trend more graphically in showing that university collaboration is one of the preferred methods of industry participating in co-operative R&D efforts:3. The role of Canadian universities in technology development is also important because the provincial and federal governments have embarked on various programs and policies for promoting the use of technology and science for economic benefit. Universities are playing an increasing role here. For example, the submission of IDEA Corporation (a venture capital operation funded by the government) in Ontario to the Bovey Commission on the Future Development of Ontario Universities clearly spelled out its ideas for commercialization of university research in Ontario . Among other things, the brief suggested that Ontario&apos;s universities need to be better equipped to transfer technology, and the reward structure in university research must incorporate industrial interests."

Jan 1, 1986

By I. R. Muirhead

"One approach to making new technology available is to demonstrate its value under full-scale operating conditions. Studies were undertaken to assess the feasibility of this approach to introducing a longwall mining system to the western Canadian coalfields.The longwall method of mining coal is described, world and Canadian usage is reviewed, and the merits of the system in comparison 10 other coal mining methods are discussed.The rationale for a longwall demonstration in western Canada is presented, along with a proposed organization for the design, operation and dissemination of the findings from such a trial. The factors which must be considered in the design of the demonstration, and in the assessment of a potential site are highlighted. It is concluded that a demonstration of this technology is both timely and essential to prepare the way for the western Canadian coal industry of future prospects for coal.IntroductionFor many years CANMET has encouraged research work organized on a cooperative basis. This requires that a working consensus must be negotiated by researchers and operators at the beginning of the project and continuously refined as work proceeds. The result is usually a more relevant selection of research problems, improved direct ion and con duct of experiment al work and often a validation phase in which research concepts are tested in an opera ting environment. All this tends to narrow the gap between obtaining research results and applying them.Even under the best of circumstances cooperative projects require a good deal of coordination and enthusiasm to maintain focus and the pace of work. The working perspective of a research scientist in a government laboratory is substantially different from that of a mine operator at a producing mine, and a common ground must be found. This is difficult to do and cooperative projects typically evolve over several years as experimental results progressively define the potential solutions to mining problems."

Jan 1, 1985