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By J. E. Dutrizac

"The end of an era in zinc metallurgy took place on July 31, 1976 when the horizontal retort furnaces of the National Zinc Company in Bartlesville, Oklahoma were permanently shut down (1) . For more than a century, horizontal retorting had been the most common method of producing zinc in the United States; it was a thriving industry in many parts of that country, especially in the natural gas belts of Oklahoma and Texas. With the Bartlesville closure, yet another metallurgical process has become an object of historical interest for North American metallurgists. Although shrouded in controversy, the origins of zinc metallurgy seem to date back at least 2000 years. Pyrometallurgical methods with carbon reductants are capable of producing zinc from oxidic zinc ores, but only above the boiling point of the metal. Although slow cooling results in re-oxidation of the zinc vapour by air or carbon monoxide, quenching yields liquid zinc; some form of rapid cooling, either accidental or intentional, was likely used by ancient metallurgists to liquify the metal. Zinc metal found in Athenian objects of the Roman era was likely of accidental origin. The Romans employed brass extensively for coins and ornaments(2) , and this was intentionally produced by the calamine process whereby oxidic zinc ores were added to molten copper under strongly reducing conditions. Zinc appears to have been known in China and India as early as 1000-1300 A.D., and was probably smelted commercially in those countries from the 14th century. Although the early metallurgical procedures were probably inefficient, they were able to produce zinc metal in significant amounts. The large heaps of zinc residues with clay retorts bear testimony to an early smelting industry of impressive magnitude. It is estimated that the heaps at Zawar, India alone represent the extraction of 100 000 tons of metallic zinc(2) In the 1730s the smelting of oxidic zinc ores was developed in England using a vertical retort method. In 1788 a British patent was granted for making zinc from zinc blends (ZnS) by roasting the ore in a coalfired reverberatory furnace, mixing the calcine with charcoal and smelting the mixture with suitable zinc condensation. The English process was very energy intensive, however, and early in the 19th century the Belgians developed a horizontal retort process for the reductiondistillation of zinc that was more fuel efficient. This technique was gradually developed into what came to be known as the Belgian process, the forerunner of the ""modern"" horizontal retort furnace."

Jan 1, 1999

By W. B. Agocs

"AbstractThe airborne magnetometer data of the Marmora iron ore deposit at Marmora, Ontario, have been used as an example to show the mapped results obtained by the use of line spacings of from 1 mile to 14 mile. The maps are illustrative of the results which could be obtained from such line spacings for any type of geophysical survey, and they show the probability of 'missing' a feature of economic value if the line spacing is too coarse.The probability equations are given for the crossing of randomly oriented features whose maximum dimension is less than the spacing of the control lines for circular, elongate, and rectangular outlines. The equations are P = D/S; P = 2L/S; P = 2(L+W)/,.S; P = A/,.S; P = (2L(S+T)-L2),.ST; and P (D(S+T-,.D)) ST, respectively; where P is the probability; D is the diameter; L is the length; W is the width; and S and T are line spacings.IntroductionTHE EFFECT of station spacing, and the effect of the distance between the plane of observation and the plane of the source of the potential field anomalies, have been studied by geophysicists in the past.The purpose of this paper, however, is to illustrate the effect of line spacing •on the resultant mapped magnetic anomaly for a known magnetite mass, and to present the elementary probability equations for determining the optimum control spacing for detecting a particular type of feature. The effect of line spacing which is illustrated by the magnetic maps presented herewith would be comparable to results which would be obtained by any geophysical survey, since the contours between lines are of necessity interpolated."

Jan 1, 1955

By K. Trapani

"The study undertaken aims to investigate an ice stope heating and cooling system for its potential to be implemented in sub-arctic mines, as a low carbon alternative to conventional natural gas and refrigeration chiller systems. Its performance was simulated for a years’ worth of data, taking into consideration hourly temperature data. Results showed that to supply the required heating and cooling loads, the ice stope system had to supplement its heating with natural heating. The techno-economic performance of this system was compared to that of a conventional heating and cooling system in a mine, with the ice stope thermal storage system hawing the lowest annuitized cost and significantly lower carbon emissions.INTRODUCTIONConventional heating and cooling, in a mine is implemented using natural gas heaters and chiller refrigeration systems respectively. This results in a significant portion of energy consumption in underground mines attributable to ventilation (De Souza, 2015), including the conditioning of the air to ensure that temperatures do not exceed work comfort standards (ACGIH, 2011). Especially at depth where heat could become a significant issue. An ice stope thermal storage, using ice as the storage medium is being proposed as an alternative to provide the heating and cooling—with the ice creation resulting in heating and the ice melting providing the cooling required. A techno-economic investigation of the two systems is undertaken to identify the capital and operating costs for the two systems, and to assess the ice stope’s potential to be considered a low cost and carbon solution for heating and cooling of mines in sub-arctic climates.NATURAL STORAGE SYSTEM – CONCEPT DEVELOPMENTThe concept for the natural storage system is developed from the ice stope at Frood-Stobie Mine, ON, Canada (Stachulak, 1991). The ice stope was developed for mine air heating, with the heating occurring by spraying warm return service water onto the cold intake air—resulting in the air temperature increasing and ice being created in the stope. In summer this ice was melted by passing warm air on top of it, resulting in slight cooling of the air but no significant temperature difference which could allow effective cooling. A schematic of the Frood-Stobie Mine ice stope is provided in Figure 1."

Jan 1, 2019

By Peter A. Hacquebard

"The early history of the Geological Survey of Canada is closely connected with coal geology investigations in the Atlantic Provinces. In 1843, Sir William Logan, the first director of the Geological Survey, measured the 4441m thick shore section at Joggins in Nova Scotia. Detailed mapping of the coalfields were subsequently carried out by H. Fletcher during the latter part of the nineteenth and first part of the present century. During the 1920-1940 period, the stratigraphy of the carboniferous WIZS' established by WA. Bell, who later also became a diretor of the Survey. Bell's work WIZS' followed by coal geology investigations of A.A. Hayes, W.S. Dyer, EA. Goranson, G. W.H. Norman, J.E. Muller, T.B. Haites and P.A. Hacquebord.The activities and accomplishments of the Survey geologists during the past 150 years are presented in this paper.General Outline of Survey Activities in Coal Geology During the Past 150 YearsIn 1842, when the Geological Survey of Canada (GSC) was established, the industrialization of the major countries of Western Europe and North America was actively persued. The energy required for this industrialization was obtained from the only fossil fuel then available, namely coal. The measure of a country's major mineral wealth at that time was the availability of mineable resources of coal. Eastern Canada, where mining had been carried out since 1720, was known to be well endowed with valuable coal deposits. In the major fields of Nova Scotia (Fig. I) several large-scale operations had been started during the middle and latter part of the nineteenth century.The significance of coal, therefore, was well understood, and exploration surveys specifically oriented toward coal were carried out by the Geological Survey from its earliest beginning. The first report of a detailed geological description of the coal measures of eastern Canada was prepared in 1843 by Sir William Logan (1845), the founder and first director of the Geological Survey of Canada. This early work was continued and complemented in 1896 by H. fletcher (1906), who during the latter part of the nineteenth century and first part of the present century systematically mapped the coal-bearing regions of Nova Scotia, which he considered all to be of approximately the same age."

Jan 1, 1992

By X. Cao

Friction stir processing (FSP) is used to produce wrought microstructures at the surface of sand-cast aerospace grade magnesium alloy ZE41A-T5. It is found that the microstructure is significantly refined in the stir zone and the flow arm. The stir zone is largely comprised of equiaxed magnesium grains of approximately 4.5 pm compared with about 50 µm in the base cast material. In the stir zone, however, abnormal growth of some grains is also observed. Vickers microindentation hardness tests indicated that the stir zone experiences some increases in hardness. Single surface passes with low distortion, lack of pores and cracks were successfully obtained indicating the great potential of the FSP technique for modifying, improving and repairing magnesium alloy castings. This will probably open new opportunities to apply magnesium alloys in aerospace industry.

Jan 1, 2007

By A. Tikhonov, D. Kipper, V. Korovin, A. Olifirenko, Yu. Shestak

The present paper deals with vanadium and molybdenum sorption from industrial wastes and intermediate processing products using Cybber macroporous strong- and weak-base anionites. Vanadium and molybdenum recovery by Cybber anion-exchange resins as well as desorption processes were studied in static and dynamic modes; their efficiency was demonstrated for that purpose. The results of the work may be used to design technologies for complex processing of both ores and industrial wastes containing vanadium and molybdenum.

Jan 1, 2011

By G. G. Hatch

FOLLOWING World War II there was an urgent need for the development of domestic sources of ilmenite to take care of the expanding needs of the titanium dioxide pigment industry. In addition, there was the interest by the pigment manufucturers and others in titanium metal. Prior to the war the pigment industry in the United States had obtained its major tonnage of ilmenite, analyzing 55- ?60 per cent Ti02, from India. However, as a result of the shipping situation which developed during the war, the pigment manufacturers had to consider the use of lower grades of ilmenite located on this continent .and several companies undertook extensive exploration programmes to locate and develop such orebodies. Probably the most significant deposit that was found as a result of these ?programmes was the orebody .at Allard Lake, Quebec, owned by the Quebec Iron and Titanium Corporation. This ?Company was formed in 1948 by the Kennecott Copper Corporation and the New Jersey Zinc Company to mine this ilmenite ore and treat it in electric furnaces to produce titanium dioxide slag for the pigment industry and iron for the steel industry.

Jan 1, 1956

By R. Charlier, G. Radioti, J. -P. Radu, S. Delvoie, F. Nguyen

"In order to investigate the fracturing of the bedrock and its possible heterogeneous distribution in situ, four boreholes equipped with double-U geothermal pipes of 100 m long were installed on the campus of the University of Liege (Liege, Belgium) over a surface area of 32 m². The bedrock, which starts at a depth approximately of 8 m, is quite fractured and consists mainly of siltstone and shale interbedded with sandstone.Different geophysical methods are applied at two different phases, after drilling the boreholes and after injecting the grouting material. The first approach consists in lowering an ultrasonic borehole imager (borehole televiewer; Zemanek, Glenn, Norton, & Caldwell, 1970), an instrument that acts as an ultrasonic transducer and receiver, into the boreholes to obtain high-resolution, continuous images with 360° coverage of the local geology and fracturing. Moreover gamma-ray logs of the four boreholes are obtained and inclinometry is conducted.After drilling the boreholes fiber optic cables are attached along the pipe loops and the double-U pipes are installed inside the boreholes. Then the grouting material is injected. The second approach consists in measuring the temperature along the fibers by applying the Distributed Temperature Sensing technique (Soto, Sahu, Faralli, Bolognini, Di Pasquale, Nebendahl, & Rueck, 2007). A laser pulse is injected into the optical fiber and the temperature along the fiber is determined by the intensity of Raman stokes and anti-stokes reemitted signals. Temperature evolution is measured during hardening of the grouting material. Local maxima of the temperature curve are probably due to a local lower thermal conductivity and/or a local larger quantity of grouting material due to gathering of fractures.A detailed fracture characterisation (position, opening, orientation, dip angle) is obtained based on the acoustic signal travel time and amplitude. The fractures are characterised by the same dipping and orientation but significantly vary in number and location in the four boreholes, despite the close distance between them. Gamma-ray data and observation of the cuttings during drilling result in rock identification through depth as well as in determination of the layer dipping. The inclination of the four boreholes tends to be perpendicular to the dipping. The combination of the two geophysical methods as presented provides information useful for the hydro-thermo-mechanical behaviour of the bedrock. The contribution of the thermal behaviour of borehole heat exchangers to bedrock investigation will be further studied by conducting Distributed Thermal Response tests (Fujii, Okubo, & Itoi, 2006). During the tests we will measure the temperature variation thanks to the installed fiber optics. These data will allow us to correlate any anisotropic thermal behaviour to the geological characteristics. The available information could be used for a detailed numerical model."

Jan 1, 2015

By W. L. Ott, C. L. Lewis

"AbstractA technique is described for preparation of palladium sponge and for spectrochemical analysis of the metal in this form. The precision and accuracy of the method are discussed. Analyses are compared with previous spectrochemical analyses of palladium in the black form. Good agreement was found in the two sets •of results and it is concluded that they are more reliable than wet chemical .analyses of the same material.IntroductionFOR SEVERAL YEARS the problem of platinum metal analysis by spectrochemical methods has been under investigation at the Spedtrographic Laboratory, Department of Geological Sciences, Queen's University. The problem, briefly -stated, is as follows: Samples of platinum, palladium,-rhodium, ruthenium, and iridium are received as fine metal powders, called sponge. Direct spectrographic analysis of this material has not been found satisfactory due to its heterogeneity •as regards contaminant metals, which may be present up to a total of one per •cent or more. Further-more, spectrographic standards are difficult to obtain and difficult to prepare accurately by adding weighed portions of contaminant metals to the sponge. The fact that •contaminant metals in original samples are probably alloyed with the major constituent is a further difficulty since complete fusion of these refractory metals proved impractical in the present case as a means of standard preparation. It •has, therefore, been found most satisfactory to dissolve the metals, prepare standards by addition of solutions of contaminant metals, and to reduce both standards and samples to a homogeneous form. A previous paper, by Hawley, Wark, Lewis and Ott (2) dealt with a method for spectrochemical analysis of platinum and palladium in their black form. Since completion of research on the black technique, the possibility of analyzing palladium accurately in its sponge form has• been investigated."

Jan 1, 1953

By R. M. Lauer

OVER THE YEARS concentration of the Sullivan ore has become progressively more difficult as the ore has become increasingly refractory. The introduction of new reagents and changes in the flow of the concentrator have been and continue to be necessary in order to maintain and improve the efficiency of metal extraction. Prior to the completion of the pilot mill in 1957 ail new ideas were developed in laboratory equipment. If these were found to be promising, there was no alternative but to introduce them directly to the main mill flow in one step. When a major change was involved there was always the possibility of serious losses while the mill was being adjusted to the changed conditions. It proved difficult to determine whether these losses were the result of the changed procedure or of failure to adjust the flow to a change in the condition of the ore during the test. The pilot mill has provided a valuable intermediate step between the laboratory and the mill. It avoids the losses which occurred when unsuccessful full-scale tests were attempted, and conversely it provides assurance that full-scale flow changes can be made without serious hazard.

Jan 1, 1960

By Craig Faulkner

Discharge cones for large Semi Autogenous Grinding (SAG) and Autogenous Grinding (AG) mills are subjected to high wear as significant volumes of ground ore and slurry exit the mill. With the larger diameter mills of 32ft to 40ft in size becoming the norm, very high, concentrated wear is highlighting the limitations of conventional discharge cones and frequent changes are subsequently required. This paper outlines the advances made in the design of the Bullnose discharge cone. Superior wear materials to increase wear life over conventional rubber or chrome-moly steel discharge cones and the introduction of key design features to reduce reline times and improve fit and safety during installation, offer significant opportunities for the mill operator. Collated from multiple case studies, the wear data and reline history from 2004 to present clearly illustrate the way in which superior component longevity has reduced the frequency of relines over the life of the product to increase mill availability and effectively increase the tonnes milled in a period.

Jan 1, 2012

By T G. Callcott

Australian coking coals are either class 434<tlj534<2l, at Port Kembla, or 634<3> at Newcastle. The former yield good blast-furnace cokes; the latter yield poor ones. However, increases in conventional strength indices, by methods applicable with normal coking ovens, seem unlikely to be economically attractive. Characterization of the coals has enabled an "economic" blend to be developed in the Newcastle area, and this has affected mining, preparation and handling operations. Coking studies have led to a specification for the making of strong coke, especially from the high-volatile Newcastle coals. Continuous coking studies, developed from the efforts to make very strong coke, have taken two directions. Firstly, coking thin layers of coal on strands; secondly, coking, in various types of vessels, compacts of coals with or with-out the inclusion of non-coking coals, iron ores or other inert materials. Gas, "sand" and hot metal coking have been tested for use in compact coking. Particular attention has been paid to pellets of coal and ore. The probable industrial problems in adopting any of the ideas are presently being examined.

Jan 1, 1963

The construction, commissioning and operation of a continuous pilot-scale selective agglomeration (oil agglomeration) unit are described. This plant has been used to recover fine coal from an effluent stream that is produced by a jig plant which scalps the coal from a New South Wales (Australia) colliery. The reject slurry is extremely fine (66.5% minus 53 um) and has an ash content of approximately 40%. The pilot plant can treat up to 0.3 tonne/h of this slurry, producing average product ashes as low as 9.1% and tailings ashes greater than 80%. The average yield observed was62%, which corresponded to a recovery of coal material of 88%. The operation of this pilot plant yielded data that enabled an economic assessment of this type of processing to be carried out. This study showed that selective agglomeration is an economically viable process for eliminating the substantial losses of coal to tailings ponds and minimizing consequent disposal and environmental problems. A commercial plant has been constructed and commissioned on the basis of the data obtained from this pilot-scale operation.

Jan 1, 1979

By P. Chollet, A Constant

THE RESULTS of a previous investigation ( 1) on the work-softening of some heat-treated steels have led to the conclusion that the occurrence and intensity of the phenomenon is possibly governed by the work-hardening capacity of the material, and the relative amount of retained austenite. The first assumption is compatible with Polakowski's theory (2) that the absence of work-softening, in steels quenched and tempered at relatively low temperatures, may be attributed to the high rate of work-hardening which compensates for, and even out-weighs, the loss of internal energy associated with the simultaneous rearrangement of the original system of internal stresses. Indeed, Polakowski first considered the work-softening as a manifestation of a partial release (by cold-working) of the latent strain energy stored in

Jan 1, 1962

By Ahmad Abdollahi

Many factors affect mechanical properties of hypoeutectic Al-Si alloys. As examples the presence of impurities such as Mn and Fe due to the formation of intermetallic phases, additions of small amounts of alkaline earth metals and cooling rate in consideration of Si formation, they all have an impact on mechanical properties of hypoeutectic Al-Si alloys. In this investigation, the effect of Fe content into the specification range of A357 alloy, the addition of different modifiers consisting of Na, Sr and Ca for the alloy of A356 and different mounting techniques for separately cast test coupons of hypoeutectic Al-Si alloys using the lost wax method were studied. The results showed that using material with lower Fe content and addition of modifiers improve mechanical properties. Also different mounting techniques resulted in different mechanical properties.

Jan 1, 2004

By J. R. Levin, E. J. Schelter

"We present some of our recent efforts in the development of predictive, directed oxidation chemistry of cerium(III) complexes under non-aqueous conditions. The electrochemistry of cerium(III)- alkali metal heterobimetallic aryloxide complexes is reported and compared with cerium aryloxide complexes that are kinetically stabilized by hydrogen bonding cations that span between the complexed aryloxide ligands. Comparative electrochemical measurements reveal differences between the heterobimetallic complexes and the hydrogen-bonded complexes.INTRODUCTIONThe rare earth elements comprise the lanthanides, La–Lu, and the element yttrium (Aspinall, 2001). Rare earth ores such as monazite, LnPO4, and bastnäsite, LnFCO3, typically bear mixtures of light rare earths: La–Sm while monazite, LnPO4, contains mixtures of heavy rare earths (Eu–Lu) (Cotton, 2006). Pure rare earth elements typically are isolated using a liquid-liquid separations process.(Bautista, 1995) The hydrometallurgy of these elements is a difficult problem because the separation factors between neighboring rare earths, which are predicated on the small differences in the sizes of the trivalent ions, are quite small (Cox, 1992). The element cerium, with its 4f1 electronic configuration in the trivalent state, is unique among the rare earth elements due to a relatively accessible 4f0 electronic configuration. The accessibility of the 4f0 configuration underlies the chemistry of cerium(IV), the only rare earth ion with molecular chemistry in the tetravalent oxidation state (Cotton, 2006). Cerium is trivially separated from mixtures of light rare earths by making use of its unique oxidation chemistry. In an effort to extend separations chemistry by oxidation reactions to other rare earth elements such as terbium and praseodymium, the solution electrochemistry of well-defined cerium complexes is of interest."

Jan 1, 2012

By Tong Guan, Guangqin Fu, Lihong Deng, Yuanlin Chen, Xiaotong Zhou

"In natural world, some kinds of scheelite minerals are rich in molybdenum. Molybdenum exists in the crystal lattice of scheelite in the form of isomorphism, and the content of MoO3 varies from 2% to 10%. As a result, the flotability of seyrigite (scheelite with molybdenum) turns to be weaker. One seyrigite mine, which has been built for 3 years,still could not produce qualified seyrigite concentrate due to the weak flotability of seyrigite (Mo-bearing scheelite) in raw ore. In our experimental research, through adopting new seyrigite collector TA-3 and advanced mineral processing technology, the seyrigite concentrate with a grade of 65.62% WO3 at a recovery of 87.47% was obtained for the raw ore containing 0.19% WO3 and 0.074% Mo. By applying the new technical achievement, for the raw ore containing 0.272% WO3, the seyrigite concentrate assaying 68.03% WO3 with a recovery of 77.56% was obtained in industrial production.INTRODUCTIONIn natural world, some kinds of scheelite minerals are rich in molybdenum. Molybdenum exists in the crystal lattice of scheelite in the form of isomorphism, and the scheelite is changed to be seyrigite (Ca[(W,Mo)O4]) (Ma, Bian, & Wang, 2013). The content of MoO3 in seyrigite varies from 2% to 10% usually, the content of MoO3 in some of the seyrigite even reaches 34%. The flotability of seyrigite is weak (Zhang, 2007), and the seyrigite is difficult to be recovered by flotation with common collectors and regulators. One scheelite mine in Anhui China, which is a skarn type seyrigite mine, has not produced qualified concentrate yet since 3 years it has been built due to the limit of beneficiation technology. Therefore, it is necessary to conduct research on the collectors with high efficiency and developing advanced processing flow for this kind of ore."

Jan 1, 2016

By T. A. Wedge

This paper suggests a crude correction for the impact of raw material quality on factor productivity in the Canadian mining industry. Such a correction would give a figure more dependent on the changing efficiency of the use of labour and capital, and less dependent on the effects of unquantified changes in inputs.

Jan 1, 1973

By J. Shibata, N. Murayama

"Rare earth elements are present in more than 100 minerals, of which monazite, bastnaesite and xenotime are typical. Rare earth elements have excellent chemical and physical properties for industrial use in functional materials such as phosphors, magnets, electronic components, abrasives and catalysts. China produces more than 90 % of the world’s rare earths, and Chinese trends significantly influence the demand and price of rare earths. From the viewpoint of resource securement, it is desirable to separate and recover rare earth elements from low-grade resources and wastes. Phosphate gypsum, which is a by-product of wet phosphoric acid manufacturing, contains low concentrations of rare earth elements. In this research, the separation and recovery of rare earth elements from phosphate gypsum were investigated. A series of recovery methods including washing of phosphate gypsum, leaching of the rare earth elements with sulfuric acid, adsorption and desorption of rare earth elements by using ion-exchange resin, and precipitation of rare earth oxalates were carried out. The separation of rare earth elements from Ca2+ simultaneously leached from phosphate gypsum was also investigated."

Jan 1, 2014

By Harry Jomini

Introduction The Wakefield plant of the Aluminum Company of Canada, Limited - a member of the Aluminum, Limited, group of companies - produces magnesia, magnesia fertilizer ingredient, and hydrated lime, from brucitic limestone. Wakefield is on the Gatineau river in Wakefield township, Quebec, some 22 miles north of Ottawa. The plant is near the western bank of the river adjacent to the Ottawa-Maniwaki highway and branch line of the Canadian Pacific railway. The plant is unique in the sense that it is the only place in Canada where brucite is processed. It is also distinguished for its outstanding safety record, as not a single lost-time accident occurred during either 1948 or 1949. The plant is amply provided with safety and comfort provisions in keeping with the standard practice in all of the twelve plants operated in Canada by Alcan and its associated companies. History Following the identification of brucite in the Rutherglen and Bryson districts in Ontario, occurrences of the mineral were discovered in the Wakefield area, Quebec, in 1939. After exploratory work on these deposits and investigation by the Bureau of Mines, Ottawa, on a method of extracting the brucite from the ore, a plant for treating the ore from the Maxwell property was built in 1941 by the Aluminum Company of Canada and commenced operations in early 1942. The process used is more or less in accordance with the method worked out by Mr. M. F. Goudge of the Bureau of Mines.

Jan 1, 1950