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By Sir Stopford Brunton

Gold was first found in Nova Scotia about 1830-40, but its significance at that time was not appreciated. Probably the first discovery that resulted in any work was made by Lieut. C. !'Estrange, at Mooseland, on the Tangier river, in 1858.1 Since that time gold has been mined with varying success until now, and from 1868 onwards work has never altogether ceased. Gold mining in Nova Scotia is at the moment under a cloud, and the idea generally accepted by most people is that it has failed in the past, and that there is no prospect for it in the future. The actual reasons for the present situation have never been carefully analysed, and it seems a good thing to see what really is the state of the case and whether or not this general idea is worthy of credence. It is the purpose of the present paper to analyse the situation in the light of present knowledge, and to set forth some data which may assist in the future development of the Province.

Jan 1, 1926

By W. H. Zieman

"THIS IS THE THIRD of the consecutive Annual Forums on Grinding that were instituted by Mr. L. E. Djingheuzian in 1957. The first was on the subject of Ball Milling (Transactions, Volume LX, 1957) and the second on The N on-Cataracting Ball Mill (Trans-actions, Volume LXI, 1958). From the discussions at these forums it was evident that one of the most important factors affecting the efficiency of grinding is the shape of the liners. In order to make a study of liners in use, it was •decided to seek the co-operation of operators across the country by sending out questionnaires requesting basic information. Additionally, these operators were urged to set down briefly any pertinent information on the subject acquired through experience and experiments at their own particular plants. A compilation and analysis of these data were to form a basis for discussion at the Forum on Liners at the Annual Meeting in Montreal, April, 1959. The response of the milling fraternity to this solicitation was most gratifying, and clearly indicated the importance attached by the operators to the effect of liner design upon overall grinding performance."

Jan 1, 1959

"9.1. IntroductionThe application of the electron microprobe for in-situ analysis of platinum-group minerals (PGM), first reported by Borovskii et at. (1959) and Genkin (1959), has resulted in a large and growing number of analyses of unidentified PGM. Figure 9.1 charts the increase in the number of reported unnamed PGM from 3 in 1959 to a total of 140 by 1979. All these minerals, with the exception of UN1968-5 and UN1976-1, were analyzed with the electron microprobe.There has been no recognised or consistent manner for reporting these unidentified PGM. The term ""unnamed"" has been used for PGM that are considered to be new species without a name as well as for PGM which have not been exhaustively compared to named and unnamed PGM in order to determine whether they are unique. Many of the so-called unnamed PGM are only unnamed because of poor microprobe analyses or because larger than usual elemental substitutions (e.g. Bi for As) made it difficult to calculate the true stoichiometry. Some of these unnamed minerals have been unnecessarily reported with non-stoichiometric formulae, as discussed by Cabri (1980). Better analytical data should reduce the number of such proposals.Another unfortunate practice, possibly used to by-pass the scrutiny of the Commission for New Minerals and Mineral Names, I.M.A., is to report a ""new"" mineral by referring to it by a name made up of its constituent elements. This has been deplored on a number of occasions (cf. discussion in Fleischer et at., 1976, p. 179), but some journals continue to publish such material. The Commission on New Minerals and Mineral Names has not recognised such ""names"" and these PGM are therefore included in this chapter with other unnamed minerals.A further example of inconsistency in reporting unnamed minerals is the report of a specific ideal stoichiometry with no further details (not even an analysis!); sometimes with a note that this will be reported in greater detail in due course. I have also been guilty of similar optimistic statements and, unfortunately, it is not always possible to follow through. Some authors give data on unnamed minerals in such a discrete manner that their reports are sometimes missed in literature searches."

Jan 1, 1979

By C. E. Lancelle, J. T. Volk, H. F. Wang, D. Fratta

"The Main Injector Neutrino Oscillation Search (MINOS) Near Detector Hall at Fermilab and the Lafarge – Conco Mine are located approximately 100 meters underground in the Galena-Platteville dolomite just below its contact with the overlying Maquoketa shale in Northeastern Illinois, USA. A new cavern was excavated adjacent to the MINOS Near Detector Hall at Fermilab to house the near detector for the Off-axis Neutrino Appearance Experiment (NOvA) program. During this excavation approximately 1150 cubic meters of shale rock were removed. Tiltmeter arrays consisting of a series of hydrostatic leveling sensors (HLS), which are spaced regularly over a total distance of 50-to-100 meters, were used to monitor subsurface deformations. The tiltmeter response in the MINOS Near Detector Hall due to the NOvA cavern excavation is approximately thirteen times the estimated response based on using laboratorydetermined properties. The discrepancy between modeled and measured tilt is likely due to differences in Young’s Modulus in the rock mass versus in a small laboratory sample. Amplitudes of measured solid earth tides differ from the amplitudes of theoretical solid earth tides by up to 40 percent for both arrays. This is likely due to a local heterogeneity or discontinuity.INTRODUCTIONLong baseline tiltmeters have been used to record small earth movements since the early 1900s. One of the first studies using long baseline tiltmeters to measure earth tides was published by Michelson (1914). He used a leveled 152-meter long, 0.15-meter diameter tube half-filled with water connecting two concrete-lined pits. The pipe was trenched 1.75 meters underground in Williams Bay, Wisconsin in a sandy-clay soil. Initially only an east-west line was used, though a north-south line was added after it was seen that viable results were obtained. Measurements were made by hand either hourly or once every two hours depending on the time of day. When compared to 0.7 times the calculated earth tides, the tiltmeter signal matched almost exactly. This excellent result began the use of long baseline tiltmeters to measure small earth movements."

Jan 1, 2015

By M. E. Holuszko

Although there is no widely accepted rigorous definition of handleability, the handling coal characteristics often referred to as handleability define whether a coal has the ability to flow unhindered through the processing and transportation systems. The handleability may be severely affected if fine coal particles tend to aggregate. In the pelletization process, the rolling action of the drum is applied to bring the individual particles into proximity with each other so that they can aggregate and form pellets. Because of apparent similarities between these two processes, the pelletization tests are carried out in parallel to the handleability tests in this project, and the pelletization results are used to explain coal handleability properties.

Jan 1, 2004

By L. E. Djingheuzian

"IntroductionIN 1940, in a series of articles, M. W. von Bernewitz(l) reviewed in detail roasting of gold and silver sulphide ores and concentrates. Since that time some significant developments in roasting have taken place, and a number of papers have appeared in the Canadian technical literature, dealing severally with the roasting of a particular ore or concentrate.The purpose of this paper is not only to review some of these Canadian papers and bring the information on Canadian roasting practices to .date, but also to analyse the mechanism of roasting. Hence, it is proposed to start with a study of physico-cl1emical factors fundamental in roasting, the knowledge of which, by creating a sound basis for a proper roaster design, makes good roasting possible.Physico-Chemical FactorsRoasting can be defined as heating sulphide ores in presence of air below fusion points of the constituent minerals, at such temperatures as to convert metallic sulphides to oxides. Hence, roasting is a chemical process.The object of roasting is, by changing, chemically, mineral constituents of sulphide ores, to make the economic recovery of the desired •Constituent metal by a subsequent standard treatment possible. For instance, pyritic ores, containing gold in sub-microscopic form which no amount of grinding would release, are roasted in order, by oxidizing the sulphides, to open up their structures to such an extent as to enable cyanide solutions to come into contact with the gold and dissolve it. The production of porous calcine is, therefore, the object of roasting of refractory auriferous sulphide ores or concentrates. Such a porous calcine may be defined as a desirable calcine, and the roasts which produce desirable calcines can in their turn be termed desirable roasts."

Jan 1, 1952

By L. B. Kilius

The composite cathode system based on Ce0.9Gdo.1O2_,5 electrolyte with a painted cathode was used for an intermediate temperature (500-700°C) solid oxide fuel cell. This cathode system was chosen due to its excellent thermal expansion match to the electrolyte, its relatively high conductivity (115 S cm-1 at 700°C), and its low activation energy for oxygen reduction (99 kJ/mol). It was found that the decrease of sintering temperature of the composite cathode system produces a significant decrease in charge transfer resistances to a level of 0.25 SI cm2. The conductivity measurements of porous samples produced values between 40 and 88 S/cm for porosities of 30-40%.

Jan 1, 2005

By J. R. Gill

Introduction The property and plant of the Falconbridge Nickel Mines, Limited, is situated about 13 miles northeast from Sudbury, in Falconbridge township, near the eastern extremity of the southern Nickel Range. As early as 1899 or 1900 some work was clone on this property by the late Thos. A. Edison, when a shaft was sunk through 80 feet of overburden to within a few feet of the ore-body. At this point quicksand was encountered, which made it impossible to continue with the equipment at hand. As a result, the activities of the Edison party ceased in this section. There was no further progress until 1915 and 1916, when an extensive diamond-drilling campaign, carried out by the E. J. Longyear Company, located the ore-body that is now being worked. The property was acquired by the present operators in 1928, and in September of that year active mining development was commenced. Features Influencing Design Of Plant Early in 1929 plans were prepared for a smelter and the necessary crushing and sorting plant. In spite of the general trend towards the reverberatory furnace as a smelting unit, it was decided to erect a blast-furnace plant. The limited tonnage to be treated, of course, influenced this decision to a great extent. However, it was known that, with the proper procedure, extremely favourable results, both economic and metallurgical, could be obtained in blast furnace smelting. The possibility of very low slag losses, the simplicity of operation by the elimination of roasting plant, fuel plant, etc., the ability to handle coarse feed, and the lower initial cost, were considered factors in favour of the blast furnace. Notwithstanding the fact that we might be called on to treat a certain amount of concentrate, it appeared that the blast furnace was the proper unit for the contemplated operation.

Jan 1, 1932

By A. Lam

The use of a liquid fed direct methanol fuel cell (DMFC) as a power source for micro and small portable applications is attractive due to its system simplicity, low temperature, etc. The aqueous methanol is directly oxidized and does not require additional fuel processing steps as in reformate based PEM fuel cells. In addition, the use of a liquid fuel is advantageous with respect to humidification, stack cooling and system energy density. The DMFC however, has technological issues that must be addressed before it can be widely adopted, particularly in larger applications such as small utility and transportation. At present, the crossover of methanol from the anode to the cathode is a major limitation on DMFC performance and fuel utilization efficiency. In this paper we discuss the influence of fuel modification on the control of crossover. This involves the use of different fuel additives and concentrations to minimize crossover. This appears to be the first reported case of the use of fuel modification (additives) to reduce methanol crossover. The rate of methanol permeation under passive conditions is discussed with respect to the different conditions.

Jan 1, 2005

By R. Siwik, N. K. Davé

"The national reactive tailings (RATS) program is a co-operative industry-government effort to develop practical techniques for closure of reactive tailings areas. This paper summarizes the RATS program objectives and areas of research, and details the Noranda/CANMET project on the Waite Amulet tailings.Geophysical and biohydrogeochemical investigations were carried out at an inactive copper-zinc mine tailings site, Waite Amulet, in Noranda, Quebec. Geophysical investigations consisted of seismic, electromagnetic conductivity and electrical resistivity surveys to determine the thickness of the layers above bedrock and to map conductivity variations within the tailings and the immediate outlying area. Biohydrogeochemical investigations consisted of installing multilevel piezometer nests to determine groundwater flow patterns and porewater chemistry, obtaining solid core samples and characterizing for physical, chemical and mineralogical parameters, and iron oxidizing and sulphate reducing bacterial counts.The geophysical survey indicated a bedrock ridge extending under the tailings from the northeastern outcrop which may act as a porewater boundary layer. The survey also indicated a 2 to 20 m clay layer underlying the main tailings dam. Preliminary results of the saturated zone porewater chemistry have indicated three major zones of high electrical conductivity varying between 1,000 to 12,000 µs and pH between 3.4 to 8. Lower pH and high metal and sulphate concentrations were obtained in a shallow zone near the water table. With depth, the concentration of metal and sulphate ions decreased and pH increased below the water table. The underlying clay layer is relatively impervious -and most of the seepage from the tailings is probably exiting from the sides of the impoundment dam."

Jan 1, 1987

"Decreasing gold-in-ore grades is one of the main drivers of poorer productivity and rapidly escalating unit costs. Grinding costs, water use and reagent consumption are all intimately related to the ore grade processed. Various pre-concentration technologies have been developed that can be applied at various stages of crushing prior to ore grinding. This paper will review the amenability of ores to coarse particle barren gangue rejection for fine crush sizes in the pumpable particle size range (i.e., particles between 5 mm and 0.3 mm in size). The liberation of oxide gangue achieved during crushing is evaluated by proxy using sink-float analysis and the deportments of gold, sulfur, and arsenic into sinks and floats are monitored. Amenability of gangue rejection by continuous gravity separation is evaluated after various crushing modes (vertical shaft impact crushing, cone crushing, and HPGR crushing). The potential to identify coarse particle mineral association and liberation using three-dimensional x-ray computed tomography will be discussed.INTRODUCTIONThe aim of research in this area is to explore some of the attributes which make some ores amenable to preconcentration, or rejection of a significant component of the feed mass to tailings at a coarse liberation size. Characteristics such as ore type, mineralogy, breakage pattern, particle shape, and liberation characteristics may need to be examined to identify amenability to pre-concentration amenability.It is intended to focus on continuous gangue rejection in the pumpable size range (0.3–5.0 mm) as this remains one of the key opportunities to reduce processing costs through a combination of techniques including screening (for mineral differentiation rather than size classification only) and gravity separation (using jigs). This is to be contrasted to conventional preconcentration as performed with automatic ore sorters."

Jan 1, 2016

By H. Miki, S. Wheatley

The addition of precipitated silica greatly enhances chalcopyrite leaching in the presence of sodium chloride at moderate temperatures (65-90°C) in acid media with ferric ions as the oxidant. The beneficial effect increases with the increase in chloride concentration and temperature. The addition of sodium silicate and silica sand has no significant influence. The analysis of solubility data in acid/salt solutions indicates that the solubility of silica as Si(OH)4 as the dissolved species is controlled by the activity of water, as expected from the hydration theory. Kinetic analysis shows the trends that copper dissolution from chalcopyrite in the presence of precipitated silica with sodium chloride follows a shrinking sphere model indicating a chemically controlled surface reaction. The effect of temperature on copper dissolution in the presence of both precipitated silica and sodium chloride was also larger compared to the results in sodium chloride alone. The SEM analysis shows that chloride and silica facilitates the precipitation of sulfur on the surface of the silica particles rather than the chalcopyrite particles which avoids the blockage of the mineral surface and thus improves the leaching kinetics.

Jan 1, 2014

By D. D. Hogarth

"Edward Haycock, Engineer and Public Contractor Edward Haycock was born in Shrewsbury, England, June 14, 1813. His father was John Haycock, a timber merchant and soap manufacturer, residing at Swan Hill Court, Shrewsbury, and his mother Esther was the daughter of William Hilton of Hempstead, Hertfordshire. Edward's paternal grandfather, John Hiram Haycock, was the first of a line of architects that ""changed the face of Shrewsbury"" and ""provided some of the best examples of typical Victorian architecture in Shropshire""(1). Nothing is known of Edward's early life or education, although it appears that he made no attempt to follow this artistic trend. In 1833, Edward immigrated to Canada. The following year, he married Mary Butler, daughter of Johnson Butler, a Lieutenant-Colonel in the Lincoln Militia during the War of 1812. Mrs. Haycock, as co-heiress of Johnson Butler's estate, was assigned 600 choice acres of farmland in Brooke Township near present-day Sarnia. This alone would have guaranteed a tidy income, but the Haycocks soon disposed of this land, the last lots being sold in May 1840. Instead, Haycock turned his hand to engineering and, for a number of years, was employed by the Great Western Railway first in Woodstock and later in Hamilton. He then moved to Port Hope, tried farming, worked in the engineering office of the Port Hope, Lindsay and Beaverton Railway Company, and later constructed a portion of this railway(2). During his stay in Port Hope, Haycock met his future partners Ralph Jones, a contractor, and Thomas Curtis Clarke, chief engineer with the P.H.L. and B. Railway Company. The alliance was styled Jones, Haycock and Company and their most successful venture was the construction of the Government Buildings in Ottawa. This work was the crowning achievement of Haycock's career and, no doubt, his proudest moment was at 11:30 a.m., April 2, 1860, when his daughter Mary Emily, then a little girl of 4, with a special silver trowel ceremoniously laid the first stone. Of special interest in this project were the quarrying operations, which introduced Haycock to the art and difficulties of mining as well as to the potential returns of mines. Sandstone, for facing, was drawn from four quarries, 10 to 12 miles from the Departmental Buildings. Haycock seems to have been in charge of these operations, which in the early stages involved an average labour force of 86 men and 43 teams. However, by 1861, quarrying had declined in importance and the contractors were able to concentrate whole-heartedly on the construction site."

Jan 1, 1999

By M. Rudolph, T. Leißner, TU Bergakademie Freiberg, C. Mämpel, R. Möckel, M. Embrechts, T. Leistner

Tin-mining activities have taken place in the region of the German Erzgebirge (Ore Mountains) for over hundreds of years up until 1991. For long times, gravity separation processes used to be the dominating beneficiation approach in those mining districts to recover cassiterite, the main tin-bearing mineral. For fine (< 100 µm) and very fine (< 20 µm) particles these approaches might not represent effective techniques, significant valuable materials could not be recovered and reported to tailings, where it was subsequently disposed. Thus, there are substantial amounts of cassiterite still present in these tailings disposals, most of it as very fine particles with already high degrees of liberation. That fact brings these tailings disposals into focus for potential reprocessing using beneficiation approaches, which are more sensitive to fine and very fine particles. In this paper we present results concerning the laboratory-scale treatment of material from exemplary heaps of the former Altenberg and Ehrenfriedersdorf mining sites using various flotation methods (including conventional froth flotation and oil-assisted flotation). Different size ranges of the material were previously prepared in order to investigate their response to the different techniques. For the study, special emphasis is put on agglomeration flotation, an oil-assisted flotation method. Therefore, an aliphatic oil phase of alkane basis is used to either selectively aggregate or collect the cassiterite particles. Recovery and flotation performance results are presented with respect to different process parameters: various collectors (including sulphosuccinamates and phosphonic acids) and depressants (including sodium fluorosilicate and oxalic acid) regime, oil dosage, agitation time and pulp density during oil/pulp agitation. Furthermore, the oil/particle aggregation behavior is analyzed via particle image analysis and, additionally, collector adsorption characteristics are investigated by contact angle measurements and zeta potential analysis. The data obtained is correlated with the testwork results achieved in order to interpret the flotation response of very fine cassiterite particles.

Jan 1, 2016

By V. Labiouse, M. Souley, N. Lafrance, C. Auvray

"Chalk rocks have been used for centuries as a strong building material and for the production of lime. The shallow underground room-and-pillar quarries where the chalk was extracted are now abandoned and endure the effects of time and weathering, increasing their risk of collapse. The risk of instability, involving natural or anthropic underground structures, is an issue for more than 10 000 towns in France.In order to investigate the causes of underground quarry collapse and to aid prevention strategies, we carried out a study of the physico-mechanical behaviour and ageing of chalk in abandoned pillars in two underground quarries, in situ-instrumented by INERIS, in the Parisian Basin, France. Core samples were drilled horizontally from pillars in the Saint-Martin-Le-Noeud dolomitic chalk quarry (Oise, France) and the Estreux glauconitic chalk quarry (Nord, France).Uniaxial tests were performed on dry and saturated cylindrical plug samples extracted perpendicular to the cores at regular distances along their lengths. Physical and mechanical properties were obtained. The dolomitic chalk (Saint-Martin-Le-Noeud) exhibits variation in mechanical and physical properties with horizontal pillar depth. Both density and compressive strength seem to increase outwards from the pillar-core to the pillar-wall. This is the opposite of that would be expected from a purely mechanical point of view. SEM analysis revealed progressive degradation and homogeneity of the grains from the edge to the inside of the pillar. At the pillar wall, the crystal faces are well-defined, almost euhedral, and the grains are of variable size. In contrast, at the inside of the pillar, crystals are finer-grained and are anhedral with highly degraded edges. In the physico-mechanical tests and SEM analyses performed on the Estreux samples, no significant variation was observed between the pillar-walls and pillar-core. However, dissolution marks were observed along the entire length of the half-pillar core."

Jan 1, 2015

By I. H. Warren, Forward F. A

The reduction of aqueous slurries of uranyl carbonate at elevated temperature with compressed hydrogen m the presence of metal catalysts and certain organic promoters has been shown. to yield uranium dioxide. The reduction takes place in a sequence of steps. The purity and sintering properties of the dioxide make it of interest as a starting material for fuel element production. Simple control can be exercised over the surface area and oxygen/uranium ratio of the product during reduction. URANIUM dioxide for fueling atomic power reactors 1s conventionally produced as a powder by simultaneously decomposing and reducing ammonium diuranate with hydrogen in a furnace at high temperature. Fuel elements are then generally made from this powder by compacting and sintering ( 1). In order that elements approaching theoretical density may be obtained,

Jan 1, 1961

By C. Graham

Thin Spray-On Liners (TSLs) have been researched and in development for over two decades and yet their fully functional and widely justifiable application in mining has yet to be achieved. While the explanation for this is partly technical, it is also clear that proving and communicating the operational and economic case for why a mine should change from mesh or shotcrete liners to a TSL is not a trivial matter. Evidence must be presented and communicated effectively, that is both obvious and compelling for a mine operator. The paper describes recent work carried out and directed towards this end, with funding from CAMIRO?s Deep Mining Research Consortium and additional support from 3M Canada and ABB Canada. The essential progress that has been, or is in the process of being made, will be described in providing the necessary proof of acceptable or superior TSL performance in the following areas: polymer formulation, health and safety, geotechnical specification, robotic liner application, business case economics and yielding ground support effectiveness. Future plans are also presented to demonstrate the performance of a new 3M composite TSL/yielding bolt support system in underground trials where the substrate rock is intended to fail through a number of mining-induced mechanisms.

Aug 1, 2013

"3.1. IntroductionAmong the six platinum-group elements (POE), four have identical cubic symmetry, two identical hexagonal symmetry (Table 3.1). Despite crystallographic differences, there is a clear relationship expressed in the chemistries of the POE: they tend to be mutually soluble in one another and can frequently substitute for one another in compounds with other elements. This chapter consolidates the data on phase relations of the POE and the compounds they form with elements selected for their known or potentially important mineralogical significance- As, Bi, Cu, Fe, Hg, In, Ni, Pb, S, Sb, Se, Sn and Te-together with selected data for the occurrence of POE in certain elements such as Au and Ag, and compounds such as FeS. Resources used to compile the data are those available from the chemical, mineralogical and metallurgical literature. First each element is discussed, with composition limits of solid solutions drawn from binary phase diagrams. Single element data are followed by a discussion of the relevant binary systems and a tabulation of data for binary compounds found in those systems (Table 3.2). Tables and diagrams for the ternary and quaternary systems for which information is available follow, and finally the very limited information on the solubility of POE in mineralogically important elements and compounds is presented.The chemical, mineralogical and metallurgical literature on the unary and binary systems is extensive and widely scattered in many languages and publications; fortunately, most of the data needed to compile this chapter can be found in reliable compendia. The most useful and most recent of these works is by Moffatt (1979), because it provides a ready index to all material relating to binary systems listed in previous compendia; furthermore, the Moffatt compendium will reportably be kept up to date by annual supplements."

Jan 1, 1979

By G. Bartolacci

In a COREM-McGill collaborative research and development project, gas dispersion parameters and froth properties were manipulated in a copper flotation plant to study interactions between the collection and the cleaning zones. In this paper, specific work on developing some relationships between operating conditions and froth stability in several different types of flotation cells is reported. Froth stability, measured by image analysis, was related to the following process conditions for specific flotation machines in an industrial case study: Gas flow rate, collector dosage, pH, frother type and dosage. Across the range examined, froth stability was improved through an increase in gas flow rate and/or frother dosage. Metallurgical results (grade and recovery) showed that both gold and copper were dependent on froth stability. Results indicated that flotation conditions could be optimized by monitoring froth stability.

Jan 1, 2007

By D. J. MacKinnon, Kazi E. Haque

Ammonia present in a variety of mine/mill waste waters was almost completely oxidized to nitrogen by chloride mediated electro-oxidation. A closed circuit operation of preconcentration of ammonia on a suitable adsorbent (e.g. zeolite or a resin) followed by brine stripping of ammonia and electrolysis of the strip liquor seems to have sound technical, economic and environmental merits. The removal of ammonia, cyanide, cyanate or thiocyanate from a mine/mill waste water (e.g. gold mill), either individually or collectively, is also feasible by chloride mediated electro-oxidation technique. Further R&D investigations are necessary for the development of a closed circuit operation for the removal of ammonia, cyanide and thiocyanate; and also to obtain technical data for process cost estimates

Jan 1, 1996