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By J. R. Shouldice

"IntroductionREEFS of Silurian age are recognized in southwestern Ontario, both in outcrop and from subsurface information. This paper deals with the so-called 'pinnacle' reefs which are known only in the subsurface. For the purpose of this paper, the pinnacle reefs are arbitrarily defined as those structures having a height of over 250 feet and a length of less than two miles. This definition eliminates numerous mounds and other broader, more subdued, structures of less certain origin, found in subsurface beds.The term 'pinnacle reef' is perhaps unfortunate, but it is in common usage in Ontario and is used elsewhere for different types of reefs. A new name is justified by the unusual environment and structure of the Ontario reefs, but it is unlikely that any other term would gain acceptance. Rather than propose a new term which would be ignored or result in further confusion and misuse, the name 'pinnacle', as defined above, is used in this paper.Pinnacle reefs have been found over a fairly large part of southwestern Ontario. The known reefs of this type parallel the southeast edge of lake Huron and •follow the strike of the structure contours which circle the Michigan basin (see Figure 1). In total, twenty-five such reefs have been discovered in southwestern Ontario."

Jan 1, 1955

By F. F. Langford

"The Athabasca Basin occupies about 100,000 km2 of the northwest corner of Saskatchewan with its western margin extending about 50 km into Alberta (Fig. 1). The basin is filled with a Helikian sequence of predominantly fluvial sandstones up to 1600 m thick. The sandstone beds are generally flat-lying, and rest unconformably on a crystalline basement which consists mostly of granitic intrusive complexes and quartzfeldspar- biotite gneisses. The basement rocks represent Aphebian sediments and Archaean basement rocks that were metamorphosed and remobilized to varying degrees during the Hudsonian Orogeny (ca 1800 Maj.Since 1968, three mining camps and several substantial unconformity-type uranium deposits have been discovered in the area (Figs. 1 and 2). These deposits lie along the unconformity surface, partially enclosed in sandstones, and partially in the basement rocks. The major deposits have elongate, pencil shaped orebodies that are parallel to the strike of underlying graphitic biotite gneisses. The total tonnage of uranium is in the order of 150,000 to 200,000 tonnes and mining grades range from 0.5 to 2.5 per cent U3O8.IntroductionUranium exploration started in Saskatchewan in 1945 when Jolliffe and Murphy headed field parties to investigate uranium occurrences on the north shore of Lake Athabasca (Kupsch, 1978). Their investigation lead to the development of the Beaverlodge camp in the following years. Some of the early prospectors were impressed by the fact that the uranium occurrences at Beaver lodge were centred on a thick sequence of unmetamorphosed arkosic redbeds which are now called the Martin Group. This sequence was referred to as the Athabasca Series by Christie (1949), and although some occurrences of uranium were found near Stony Rapids and Black Lake, the vast expanse of Athabasca sandstones south of Lake Athabasca was generally regarded as unpromising."

Jan 1, 1986

By R. W. Allgood

"THE world-wide shortage of elemental sulphur, which became sharply apparent in 1950, has focused attention on the commercial exploitation of sulphur-bearing materials such as pyritic ores, sour natural gas, and smelter gases. Although there •are no known commercial deposits of elemental sulphur in Canada, there are vast quantities of these sulphur-bearing materials. The International Nickel Company of Canada and Canadian Industries Limited have for many years collaborated in an effort to develop economic processes for the recovery of sulphur from the smelter gas arising from Inco's metallurgical operation at Copper Cliff, Ontario. While sulphuric acid has been •produced at Copper Cliff for over twenty years, recent developments will result in a 60 per cent increase in acid production early in 1952 and, later in the year, in commencement of the operation of the largest single unit ever erected for the manufacture of liquid sulphur dioxide.The purpose of this paper is to discuss •briefly the general factors associated with the recovery of sulphur from the Copper Cliff smelter gases and to describe the sulphuric acid operations and the liquid sulphur dioxide development.Processes for the manufacture of elemental sulphur, liquid sulphur dioxide, and sulphuric acid from sulphur-dioxide-bearing smelter gases are well known and in some cases •highly developed."

Jan 1, 1952

By Juan Asalgado

The JORC and NI43-101 codes impose that mineralized material has a reasonable prospect of economical extraction to be classified as Mineral Resource. For deposits close to surface and amenable to open pit mining, it is easy to show reasonable prospect of economic extraction running a Lerch-Grossman optimization. The Lerch-Grossman pit provides a transparent and repeatable way of separating the Mineral Resource (within the pit) from the remainder of the mineral inventory (outside the pit). Deposits amenable to underground mining are more challenging because of the variety of the underground methods. AMEC developed a stand-alone software package that outlines the material which has reasonable prospect of economic extraction for open stoping, block caving, sublevel caving and room and pillar. The software takes a block model file in ASCII and exports a 3D surface outlining the part of the mineralization that has a reasonable prospect of economic extraction, and which the Qualified Person can smooth out manually if required.

Oct 1, 2009

By R. P. Charbonnier

"To understand the operation of jigs and other separating processes based on differences in gravity, it is desirable to analyse the motion of various particles in given media under specific conditions. A summary of the earlier theories shows that they lead to unsatisfactory or excessively complicated formulae in cases such as coal jigging. By adopting a simplified theory of the motion of particles in a fluid, the size and duration of the initial accelerated motion of a particle falling in hindered settling can be calculated. Based on this mathematical analysis, examples referring to actual coal jigging practice show that it is desirable to prolong and/or repeat, as frequently as possible, the optimum conditions corresponding to an effective acceleration of the particles. The separation is then obtained according to gravity rather than to particle dimensions, as would be the case if the velocity of the particles• were allowed to approach its terminal value. To achieve this gravity separation, it is suggested that the suction phase of the jigging cycle be artificially prolonged and the frequency of pulsations increased as much as possible for washing the coals of smaller sizes."

Jan 1, 1959

By A. Trusiak

"Increasing energy costs in mineral processing is making it necessary for tighter controls over various parts of the concentrating process. Continuous monitoring and control of critical process streams can be easily performed by today's many computer systems. Indeed, the list of successful applications of computers to grinding and flotation control continues to grow. The day is rapidly approaching when the use of computers within concentrators for either process control or simply metallurgical accounting will no longer be a luxury, but a necessity. The benefits from such applications far out weight the initial investment.This paper describes the current application of a process control system at Brunswick Mining in north-eastern New Brunswick. Emphasis is placed on the control of a CuPb flotation circuit, and the benefits derived-from this control.No. 12 Cu-Pb Flotation: The complex nature of the Brunswick flotation process has been described else-where. 1,2,3 Four final concentrates are eventually produced, these being a Zn concentrate assaying 53% Zn, a 30% Pb concentrate, a 20% Cu concentrate, and a bulk Pb Zn concentrate assaying 35% Zn and 17% Pb. The Cu concentate, Pb concentrate, and bulk Pb Zn concentrate are all derived from a primary CuPb concentrate assaying 26% Pb, 11% Zn and 1.8% Cu.The No. 12 CuPb circuit produces approximately two thirds of the total primary CuPb concentrate. No. 12 ore, assaying 3.5% Pb, 9% Zn, 0.25% Cu and 100 g/tne silver, is ground in two parallel grinding circuits. Each line uses a 3.2 x 4.2 meter rod mill in closed circuit with two parallel 3.2 x 3.9 meter ball mills. Ball mill and rod mill discharges are classified in two stages of cycloning. The secondary cyclone overflow, or flotation feed, is controlled at 65% passing 37 microns."

Jan 1, 1981

By L. Bichler

Lightweight magnesium alloys are gaining in popularity for applications in the automotive and aerospace industries, Their use, however, remains limited due to their relatively low strength and creep properties. Lost Foam Casting (LFC) is a new casting process and the strength of foam cast magnesium alloys has not been investigated in great detail thus far, In this research, magnesium alloy AZ91 E and three new alloys were cast by the LFC process to study the effect of varying aluminum and manganese content on the alloy's tensile properties, The study reveals, that the tensile strength of the magnesium alloy is closely related to the relative amount of aluminum in the system. Formation of ß-Mg17Al12 phase was seen to significantly affect the yield strength and ductility of the alloy, Furthermore, formation of manganese intermetallic compounds was seen to effectively increase yield strength of the base alloy, Individual alloy morphologies were analyzed via optical and SEM techniques.

Jan 1, 2004

By L. O. Cooper

IN THE operation of most mines, hoisting ropes, made of steel, play a very important part in the conveying of men and material between surface and the underground workings. It is obvious that, in order to maintain a maximum degree of safety, certain restrictions must be placed on the loads that may be carried by hoisting ropes, as well as on other factors that may affect the life of the rope. It is the purpose of this paper to suggest ?a new method of defining the necessary restrictions. The three main stresses in a hoisting rope are the static stress, bending stress, and dynamic stress. Crushing stresses, which are also present, are largely indeterminate and may best be allowed for by proper grooving of drum and sheaves, by adequate inspection of cross-over points, and by limiting the number of layers on the drum. They will, therefore, not be considered in this analysis. In the ?recent Ontario regulations, the limiting conditions for the main stresses are specified separately. The static stress is limited by setting a minimum static safety factor of 5.0 The dynamic stresses are allowed for by specifying a minimum capacity factor of 8.5, which has the effect of increasing the safety factor required at smaller depths in a uniform manner. The bending stresses are limited by calling for a drum-dia./rope-dia. ratio of at least 60 for ropes up to 1 inch in diameter and 80 for ropes greater than 1 inch in diameter. One disadvantage of this method is that the controls are too rigid and do not allow the operator sufficient freedom of action within safe limits.

Jan 1, 1951

By Yugo Mitani, Tatsuya Kato, Chiharu Tokoro, Abdullah Al Mamun

Acid mine drainage (AMD), which is a major source of mining pollution, often contains ferric and/or ferrous ions together with several toxic elements. The ferric and ferrous ions in AMD precipitate in several mineralogical forms after neutralization, and the ferric/ferrous precipitates become the main component of the sludge generated after AMD treatment. The precipitates are also good absorbents for several toxic elements. To avoid generation of voluminous sludges and the re-dissolution of toxic elements from the sludge, it is very important to generate well-draining and efficiently adsorbing sludges by controlling the mineralogical form of the ferric/ferrous precipitates. Green rust, which is ferric and ferrous hydroxide, is a double layer hydroxide which is able to sorb several toxic elements. The green rust transforms to goethite or lepidocrocite by rapid oxidation, whereas it transforms to magnetite at ambient temperature by slow oxidation. The magnetite is also good absorbent especially for toxic cations and it makes a compact sludge due to its magnetic properties. We investigated the magnetite generation process at ambient temperature in detail. The magnetite generation process can be divided into three steps; (i) oxidation of Fe(II), (ii) Fe(II) surface complexation to Fe(III) hydroxide, and (iii) crystallization of magnetite. More magnetite can form when the oxidation rate is slower than the crystallization rate, and optimum conditions for its formation are at pH 9.5 with mild agitation. Ferrihydrite is the most common precipitate and it is able to sorb many different toxic elements. However, it drains badly and its solid/liquid separation properties are poor. We investigated the removal mechanism of several toxic elements by co-precipitation with ferrihydrite. We confirmed that the removal mechanism by co-precipitation partly involved surface precipitation when the initial ratio of toxic elements to ferric ion was high, although the main mechanism was always surface complexation. When surface precipitation occurred, highly efficient toxic element removal with ferrihydrite could be achieved.

Jan 1, 2016

By L. I. Kiss, S. Perron, S. Poncsák, A. Perron

Aluminium industry has an increasing interest in the diminution of the energy consumption of the Hall-Heroult process by the reduction of the anode bottom covering with gas. Electrically isolating carbon-dioxide bubbles, produced at the anode, increase the ohmic resistance of the cell. As the gas production rate is determined by the applied current density, anode covering can be decreased only by a faster evacuation of the gas from the inter-electrode space. Among others, the inclination and curvature of the anode bottom promotes the release of the bubbles and thus decreases the mean value of the covering. Indeed, anode, insert in the molten cryolite bath has a square shape with horizontal bottom. However, inhomogeneous anode consumption, electro-erosion, bath circulation and the inclination of the bath-metal interface modify this shape gradually during electrolysis. Anode bottoms become inclined with rounded comers. This concentrates the gas generation to the center zone of the anode. As the bubble layer cannot be observed directly because of the hostile environment and the opacity of the bath, real scale air-water systems are used to study the impact of the anode geometry on the anode covering and the bubble induced flow. However, the physical properties of such a system are different than that we can found in the real cells. A simulator using the Lagrangian description of the bubble layer has been built and presented in earlier papers. This tool was used to investigate the effect of the anode inclination on gas covering and bath velocity, for both C02-cryolite and air-water system. Results obtained for the second system were compared to experimental data .

Jan 1, 2006

By R. O. Grieve

"IntroductionCALEY (1945) and Evans (1950) pointed out that certain instances of convergence between Devonian and Silurian horizons, frequently evident in wells drilled for oil and gas in Ontario, appear to be related to local thinning of salt beds in the Salina formation and they suggested that leaching of the salt beds may have occurred. Exploratory drilling by Imperial Oil Limited since 1945 has brought to light several examples of structures similar to those discussed by Caley and Evans. The writer has had the opportunity to examine cuttings and data from wells which penetrated these structures and the attempt to interpret them in the light of the theory of leaching and subsidence proposed by Landes ( 1945a) to explain the marked brecciation and deformation of Upper Silurian and Middle Devonian sediments which crop out in the Mackinac Straits region of northern Michigan has led to the observations presented in this paper."

Jan 1, 1955

By Rufus L. Chaney

A new technology is available to the Ni mining and remediation community to “phytomine” Ni from mineralized or contaminated soils using rare plants which hyperaccumulate Ni to over 1% of shoot dry matter. Research has identified useful plant species, and even bred improved cultivars of Alyssum murale and Alyssum corsicum for commercial phytomining in temperate regions. All agronomic practices (fertilization, soil amendments, planting and harvest methods) needed for economic phytomining were identified to attain high yields and high Ni concentration in the biomass. In tropical regions, other species are available such as Phyllanthus which accumulate over 1% Ni in dry shoots. These species are perennial so they regrow after annual cutting to harvest biomass. Expiration of our patents on the technology opens the opportunity for other organizations which control Ni rich natural soils or contaminated soils requiring remediation to commercialize the technologies. Inexpensive methods to remediate/revitalize Ni contaminated phytotoxic soils using agronomic approaches have also been developed and demonstrated at Port Colborne, Ontario, but adoption is delayed until formal agreements with government are completed. These new simple remediation and profitable phytomining technologies can obtain Ni from soils which contain Ni well below levels considered economic for current mining technologies, and the plants biopurify the Ni so it is easy to recover Ni metal from plant ash by pyrometallurgical or hydrometallurgical technologies. Although increasing pH decreases the solubility of Ni in all soils, raising pH increases Ni accumulation by Alyssum species. Hence usual chemical extraction methods for phytoavailable soil metals such as the DTPA- or NH4-OAc-extraction cannot predict Ni accumulation by Alyssum species.

Jan 1, 2016

By Martin Encinas, Jesús L. Valenzuela, Jose R. Parga, Salvador Aguayo, Roy G. Lewis

Continuous laboratory solvent extraction of gold from cyanide solutions using LIX?79 guanidine based extractant has been investigated. Different variables that affected the selectivity and extraction include aqueous pH, extractant concentration, and modifier concentration. The extraction isotherms of the aurocyanide complex with respect to the other cyano anions were compared, and the following order of selectivity Au > Ag > Zn > Cu > Fe was observed. According to the pH isotherms, aurocyanide can be extracted in an alkaline media, and a better separation with respect to the other cyanoanions was obtained in the pH range 10.5-11.2. From the McCabe Thiele diagrams, better recovery was predicted when using LIX?79 extractant and tridecanol modifier at 10 vol.%. Stripping of the gold from the loaded organic was carried out at pH > 12 using NaOH and NaCN solution. The continuous tests indicate that a two-stage extraction followed by a single stage strip is adequate to obtain an overall process efficiency of >90%. Better results were obtained using a copper wash stage before gold stripping.

Jan 1, 2014

By W. S. Dyer

The Minto coal basin lies in the central part of the province of New Brunswick, near the head of Grand Lake. The village of Minto which is the centre of mining activity of the district, lies about 35 miles east of Fredericton and somewhat greater distances to the north and west of the cities of St. John and Moncton respectively. Although coal has been mined in the basin for a number of years, it was not until recently that the production became sufficient to warrant a thorough geological investigation. The summer of 1922 was spent, in accordance with in structions from the Director of the Geological Survey, in making a detailed study of the geology and coal resources of the Minto coal basin, which is covered by the Minto and Chipman map sheets, each embracing an area of 200 square miles. The present paper is a short outline of the principal results obtained in the field. The writer wishes to acknowledge the assistance cheerfully given him by the managers and officials of the various companies operating in Minto. He wishes especially to thank Mr. W. B. Evans, Manager of the Rothwell Coal Company, for assistance in the collection of fossils and for the generous supply of information relative to the early history of the coal field.

Jan 1, 1924

By H. E. T. Haultain

Research is a much over-overworked word, sometimes a much abused word; the result of this has been that many who really need the word avoid it, shy away from it just as we do from that most useful word camouflage. We have not been altogether happy in our substitutes. Some years ago I spoilt a very good proposition by using the word investigation. There were those who thought that men and methods were to be investigated instead of simply processes. They expected disruption instead of co-ordination. The bad psychology up-set the scheme. The word experiment is even worse in its psychology. To the mind of the "practical" business man experiment denotes ignorance, waste of time and money and presupposes failure. It is not so long ago that the recognized way of improving the methods about a mine was to get a new manager. Until comparatively recently the average life of a boss in a mine in the West was under, rather than over, two years. Certainly was this the case in the smaller mines. Directors did not recognize that a cock-sure new boss was a greater experiment than a certain amount of feeling-his-way on the part of the old one. We always say that no two mines are the same but we are only now realizing to what extent the fine points of the game can and must be learnt on the job itself. One of the main differences between a small property and a large one lies in this study of the fine points of the game. In the early stages operation is the main point-get her going and keep her going.

Jan 1, 1924

The steam-filtration process for dewatering solids involves the application of slightly superheated steam to a filter cake during filtration. The mechanism by which the technique promotes water removal has been deduced from bench-scale experiments on coal and on granular iron ore concentrates. The mechanism, along with some of the applications and limitations of the process, is presented. Introduction I N the steam-filtration process, slightly super-heated steam is applied to the filter cake during filtration to remove more water than can be extracted by conventional filtration. Although this process was developed by Burton for coal filtration (1), it should have far wider applicability; certainly, it could be used to treat any mineral product, because only low-temperature steam is needed and most conventional filtration equipment can be easily adapted to it. As few restrictions apply to this process, however, it is important that its more obvious advantages and disadvantages be appreciated and, especially, that the criteria on which economic evaluations can be based are understood.

Jan 1, 1965

By N. Plint, M. Potgieter

The Anglo Platinum Mogalakwena North concentrator was one of the first three hard rock mineral processing applications to utilise a HPGR circuit in preference to a SAG milling circuit. This was driven by the extreme competence of the ore that had given rise to throughput issues on the original South Plant. Despite more than adequate capacity and performance of the individual comminution units, the circuit has struggled to obtain full design capacity. A thorough review of the integrated performance of the circuit revealed a wide range of bottlenecks and underutilised parts of the circuit arising from design issues. Interestingly, the major opportunities lie in materials handling issues and mismatch of loads about the circuit. This paper presents the high-level outcomes and the associated opportunities, and is pertinent to all HPGR circuit designs.

Jan 1, 2012

By R. F. Neider, W. R. Bain

"Expanding upon one aspect of a recent paper on ""Fluid Column Roasting at Sherbrooke Metallurgical Co. Ltd.,"" the present paper deals with the operation of the fluid column process to achieve substantial elimination of cadmium and lead during the roasting of pelletized zinc concentrates. Designed to meet the need for additional feed for Matthiessen and Regeler Zinc Company's vertical retort zinc smelter in West Virginia, without recourse to a sintering operation, the plant is capable of simultaneously attaining very low lead and cadmium levels on demand, through operation in the manner described. Fluidizing air admitted via the wind box is supplemented by natural gas admitted via a tuyere bank 15 ins. above the hearth, in quantities adjusted to maintain a reducing atmosphere within the interstices of the bed. In addition, careful attention is paid to bed temperatures, which run from 1,080° to 1,100°C. Under these reducing conditions, 90 per cent of the cadmium and 92 per cent of the lead in the feed are eliminated, the sulphate sulphur content is decreased by 0.5 per cent, sulphide sulphur is held at 0.6 to 0.08 per cent, and the zinc content correspondingly in-creases. The fuel value of the natural gas is recovered as extra steam, which carries a credit. There are some added difficulties with fume accretions, gas conditioning and gas -cleaning, some of which have yet to be overcome."

Jan 1, 1967

By W. R. Hopkins, J. A. Davis

"This paper presents a discussion of the mechanisms by which aerosols of the process electrolyte are entrained into the breathing environment of copper, Zinc and nickel eIectrowinning tankhouses. Literature outlining the health effects associated with worker & posure to the acidic and metallic contaminants found in the airbome aerosols is summarized and compared with existing North American regulations.A brief review of the existing technologies for the source reduction of these aerosols is presented. This paper outlines the industry experience with use of covers, balls, beads, shapes, fixtures and chemical surfaetants. Each of these devices is ranked according to its effusiveness in the process in which it is used, and rated according to its operator acceptance.The various forms of existing in-plant ventilation systems are reviewed with a discussion of their relative merits and effectiveness. Actual experience is related, detailing the methods of testing for ambient contaminant levels in a variety of tankhouse environments. Guidelines are provided for the site and process specific criteria which govern the selection and ultimate effectiveness of a particular form of ventilation system.Finally, actual project experience is cited in which hydraulic modelling is used a design tool in tankhouse ventilation design. These projects include the upgrading of existing traditional ventilation designs, and the ''grass roots"" design of a more efficient aerosol source control system to be used in high altitude, cold weather sites."

Jan 1, 1994

By D. R. Derry

This paper up-dates an earlier paper by the author on the rate of new Canadian mineral discoveries and the exploration methods which were principally responsible for these finds. He concludes that the ratio of exploration expenditure to production value must be increased if we are to provide sufficient new reserves for the future.

Jan 1, 1970