Search Documents

By K. D. Card, K. Howard Poulsen

Abstract - The Archean Superior Province craton and the Paleoproterozoic Penokean Orogen are major geological sub-divisions of the southern Canadian Shield and account for much of the metallic mineral production of North America. The Superior Province experienced a mainly Archean history involving several cycles of volcanism, plutonism, and tectonism, primarily in the Neo-archean but also including Meso-archean and Paleo-archean cycles as well. Superior Province consists of northern and southern high-grade gneiss sub-provinces and a broad central region of alternating greenstone-granite and metasedimentary belts. The sub-provinces may represent tectonic terranes assembled in the Archean by accretion processes similar to those of some Phanerozoic orogens. Most of the mineral deposits, including VMS, intrusion-related, and lode gold deposits occur in the greenstone- granite sub-provinces where they were formed in an interval of 100 million years or less around 2.7 Ga. The Paleoproterozoic Penokean Orogen comprises supracrustal sequences deposited in fault-controlled epicratonic and rifted margin settings developed on and about the Superior craton. Deposition of the ~2.4 Ga Huronian Supergroup and its paleoplacer uranium deposits in the eastern Penokean Orogen, and their pre-2.2 Ga deformation, were probably unrelated to the deposition of the ~2.1 Ga Marquette Range and Animikie groups and their major taconite iron formations in the west. However, these sequences were deformed together during the ~1.85 Ga Penokean Orogeny which resulted when an assembly of island arcs containing VMS deposits, the Wisconsin magmatic terrane, collided with the Superior block and its Paleoproterozoic cover. The Sudbury structure with its world class Ni-Cu-PGE ores was also formed at this time, possibly triggered by meteorite impact. Metallogenic patterns in the Paleoproterozoic rocks were controlled by a complex interplay of factors including tectonically controlled variations in deposition and deformation, distribution of mineralization in the Archean basement, and oxyatmoversion, the transition from anoxic to oxygenic atmospheric conditions that occurred during the deposition of these sequences.

Jan 1, 1998

By J. Asfahani

"The inverse slope method (ISM) was applied to reinterpret vertical electrical soundings (VES) data from pits at the Al-Sharquieh phosphate mine, in order to demonstrate applicability and suitability of the ISM for interpreting VES data from sedimentary phosphatic environments. The ISM overcomes limitations of the curve matching method and the complexity of lithological sections. The ISM geo-electrical interpretation results correlated well with lithologies of the pits. This method characterized resistivity and thickness of the phosphatic layer, and identified favourable phosphate-prospecting areas using the newly developed thickness/depth parameter. The ISM is recommended for interpreting VES measurements in similar sedimentary phosphatic regions.RÉSUMÉ La méthode d’inversion de la pente (ISM) a été utilisée pour réinterpréter les données de sondages électriques verticaux (VES) effectués dans des puits de la mine de phosphate Al-Sharquieh, afin de démontrer l’applicabilité et la pertinence de cette méthode pour interpréter les données VES dans des environnements de sédimentation de phosphates. Cette méthode (ISM) surmonte les limitations de la méthode de comparaison de courbes et la complexité des sections lithologiques. Les résultats de l’interprétation géoélectrique ISM correspondaient bien aux lithologies des puits. Elle a permis de caractériser la résistivité et l’épaisseur de la couche phosphatique et d’identifier les secteurs favorables à la prospection pour le phosphate en utilisant le paramètre nouvellement développé épaisseur/profondeur. ISM est recommandée pour l’interprétation des mesures VES dans des régions semblables où se trouve du phosphate sédimentaire."

Jan 1, 2016

By M. F. Goudge

BRUCITE associated with highly metamorphosed Precambrian limestone was discovered in the vicinity of Rutherglen in northern Ontario by the writer during field work on the limestones of that district in 1937, and later was identified in similar limestone at Bryson and Wakefield, Quebec. The brucite occurs as granules disseminated through the limestone (Figure 1) and comprises from 20 to 35 per cent of the rock. Such rocks may be referred to as predazzites or pencatites, depending on the proportions of the constituent minerals. In this paper, however, the general term brucitic limestone is used to designate limestone containing brucite. In none of the deposits does the magnesia content of the rock approach that of magnesite, and in the deposits near Bryson and Wakefield the magnesia content is only that of dolomite. Therefore, without some method of concentrating the brucite, the deposits would be of little or no more value as a source of magnesia than is ordinary pure dolomite, which is abundant in many parts of Canada. Investigations in the laboratories of the Bureau of Mines have, however, resulted in the development of a method whereby, from certain of the deposits, pure calcined brucite, or magnesia, in granular form can be obtained, apparently at a cost that will enable it to compete in eastern Canada with imported magnesia. The granular magnesia so obtained appears to be highly suitable for use in basic refractories, for making magnesium metal, and for various other purposes for which magnesia is commonly used. Prospecting in the neighbourhoods of the original discoveries has resulted in a number of other deposits being found in each of the three areas, and there is now apparently available s1.dficient brucitic limestone of a grade that will lend itself to commercial exploitation to supply for many years a large part of the present and prospective Canadian market for magnesia and its products. Furthermore, it is expected that additional deposits will be discovered as prospectors and others become more familiar with the appearance of brucitic limestone.

Jan 1, 1940

By M. Tadayonsaidi

The effect of alloying elements on the mechanical properties and thermal expansion of 336 casting alloy usually used as piston alloy which has low thermal expansion and very good high-temperature mechanical properties and good wear resistance was investigated. The mechanical properties and thermal expansion characteristic of samples with different combination of alloying elements, which enhance to reduce the cost of products, have been studies, The results show remarkable increase in the mechanical properties with increasing the amount of Cu and Mg, while are reduced with increasing amount of Ni, On the other hand, the use of eutectic aluminum alloy as 336 alloy with higher percent of Cu and Mg and lower percent of Ni are recommended for industry, due to economical viewpoint and satisfactory properties.

Jan 1, 2005

By Helmut Ehnes

Over 330 million accidents at work happen world wide every year, only counting those leading to more than four days absence. More than 350,000 end fatal. Two million people more die every year due to work-related diseases. To sum this up: around 2.4 million people die every year because of work conditions. Among many risky industries, mining stands out. While mining represents just 1% of employees globally, it unfortunately represents 8% of all occupational fatalities. Mining operations go along with a variety of hazards. Not only in large operations, as they first come to mind, but also in the manifold small scale mines, with an estimated 13 million labourers worldwide exposed to substances such as dust, mercury and other chemicals, while also dealing with poor ventilation, inadequate space and overexertion. But is the number of severe accidents and diseases inevitable or can we change this situation? We can make mining sustainably safer, but we need a successful strategy to do so. A high potential lies in Vision Zero. Vision Zero is a prevention strategy for a safe future without fatal or serious occupational diseases, work accidents and traffic accidents. First defined as early as in the 19th century by Eleuthère Irénée du Pont, its very successful elements were adopted by many European countries first aiming at road safety, then extended to safety and health at work. Vision Zero?s holistic elements cover technology, workplaces, rules, and people as fields of action. By focussing on severe and fatal accidents, its application increases the level of safety and health overall.

Aug 1, 2013

By J. Fellowes, Z. Liang, J. Robson, M. Kenyon

"Dispersoids play a significant role in the recrystallization and texture development for wrought Al-Mg-Si (6xxx series) alloys by inhibiting grain boundary motion. It is therefore important to understand the precipitation kinetics of such particles. It is the additions of Mn and Cr in Al-Mg-Si based systems that can lead to dispersoid phases being formed. These phases are currently thought to nucleate on ß’-Mg2Si via an intermediate semi-coherent precipitate. Scanning transmission electron microscopy (STEM) has been conducted to study the precipitation of a-Al(CrFe)Si and a’-AlCrSi dispersoids. Corresponding electron dispersive spectroscopy (EDS) has been used to distinguish the dispersoids. The volume fraction and size distribution of dispersoids has been measured as a function of distance across a grain. Electron probe microanalysis (EPMA) has been conducted to study the inhomogeneity of elements in the cast structure and the effect on dispersoid precipitation. Dispersoid free regions have been observed in the microstructure correlating to regions depleted in the dispersoid forming elements.INTRODUCTION Al-Mg-Si (6xxx series) based alloys are increasingly being used in the automotive industry. The primary reason is to reduce the weight of vehicles, resulting in a reduction of CO2 emissions and increased fuel efficiency. The demand for 6xxx series is predicted to increase over the coming decade. Due to the high cost and CO2 emissions produced by raw extraction of aluminium, close loop recycling of these alloys becomes a more important process. However recycling of automotive alloys can be difficult due to pick up of impurity elements such as Mn, Cr and Fe. The addition of these elements can form dispersoid particles during early heat treatment processes. Although a controlled population of dispersoids is necessary to control the grain structure during thermo-mechanical processing, a significant change to the dispersoid population due to a composition change could profoundly influence the final microstructure, affecting the final properties of the material. More research is required on the precipitation and effect of additional minor alloying elements; in order to increase the 6xxx series alloys recyclability."

Jan 1, 2018

By Chantale Doucet

L?utilisation du remblai en pâte dans les exploitations en vrac est de plus en plus importante. Puisque la technologie existe pour fabriquer du remblai en pâte sans construire une usine coûteuse, il est maintenant possible d?élargir le domaine d?utilisation du remblai en pâte pour y inclure des gisements filoniens où le besoin annuel de remblai est moindre. Dans certains cas, l?utilisation du remblai en pâte pourrait permettre de réaliser d?importantes économies telles que la réduction de la dilution, la stabilité des ouvertures, la récupération d?une plus grande partie du minerai par la réduction de la taille des piliers et l?entreposage de moins de résidus à la surface. L?ampleur des économies est parfois difficile à chiffrer mais il est tout de même important d?en tenir compte lors de la décision d?utiliser du remblai en pâte puisque ce sont souvent ces économies qui seront déterminantes. Différentes méthodes d?extraction avec remblai en pâte appliquées aux mines filoniennes seront présentées. Des défis et les solutions reliés à l?utilisation du remblai en pâte à la Mine Doyon seront discutés.

Oct 1, 2001

By Daniel J. Schulze

Abstract-Eclogite is an important source of diamond in the upper mantle, but is more localized than peridotite. Using eclogitic minerals in kimberlite and diamond exploration is also more problematic than using the well-known peridotite-derived indicator minerals Cr-pyrope and magnesiochromite. The problems include color similarities between orange garnets from eclogites, Cr-poor megacrysts, and crustal garnets, chemical similarities with Cr-poor megacryst suite garnets (specifically elevated Na2O contents), and low abundance of eclogite garnet xenocrysts in most known kimberlites. Chemical screens must be used carefully to distinguish between varieties of orange garnets in exploration samples. For example, most orange garnets of crustal origin have >22 wt% FeO, with mantle eclogite garnets having lower values. Na2O-bearing garnets from the Cr-poor megacryst suite can be distinguished from Na2O-bearing garnets from diamondiferous eclogites by the elevated TiO2 contents of the former. The low abundance of eclogite garnet xenocrysts in kimberlites worldwide, however, may dictate that use of eclogite garnets in diamond exploration in most cases be restricted to advanced stages of kimberlite exploration and evaluation of kimberlite diamond potential. Crpyropes, Mg-ilmenites and Cr-rich chromites are more useful than eclogitic garnets in most stages of diamond exploration. If orange garnet xenocrysts are sought in a kimberlite exploration program, those from the Cr-poor megacryst suite will be more useful than eclogite derived garnets, due to the typical great abundance of the former, although they carry no information of the diamond potential of the host kimberlite.

Jan 1, 1997

By Daniel J. Schulze

Eclogite is an important source of diamond in the upper mantle, but is more localized than peridotite. Using eclogitic minerals in kimberlite and diamond exploration is also more problematic than using the well-known peridotite-derived indicator minerals Cr-pyrope and magnesio-chromite. The problems include color similarities between orange garnets from eclogites, Cr-poor megacrysts, and crustal garnets, chemical similarities with Cr-poor megacryst suite garnets (speci?cally elevated Na2O contents), and low abundance of eclogite garnet xenocrysts in most known kimberlites. Chemical screens must be used carefully to distinguish between varieties of orange garnetsin exploration samples. For example, most orange garnets of crustal origin have >22 wt% FeO, with mantle eclogite garnets having lower values. Na2O-bearing garnets from the Cr-poor megacryst suite can be distinguished from Na2O-bearing garnets from diamondiferous eclogites by the elevated TiO2contents of the former. The low abundance of eclogite garnet xenocrysts in kimberlites worldwide, however, may dictate that use of eclogite garnets in diamond exploration in most cases be restricted to advanced stages of kimberlite exploration and evaluation of kimberlite diamond potential. Cr-pyropes, Mg-ilmenites and Cr-rich chromites are more useful than eclogitic garnets in most stages of diamond exploration. If orange garnet xenocrysts are sought in a kimberlite exploration program, those from the Cr-poor megacryst suite will be more useful than eclogite derived garnets, due to the typical great abundance of the former, although they carry no information of the diamond potential of the host kimberlite.

Jan 1, 1997

By B. Konda, R. Lauer, D. Camilucci, D. Gladwin

"Income based taxes are significant cost elements to be considered in evaluating investment in new mine development. This paper presents the results of comparative analysis of effective income-based tax rates for mining in the Northwest Territories (NWT), selected Canadian provinces and international jurisdictions. The study was done as background to a review of royalty regulations for the NWT. ObjectiveThis paper presents results of comparative analysis of effective mining royalty1 rates, and combined effective mining royalty and income tax rates on selected mine models for the Northwest Territories (NWT), with those for several other jurisdictions in Canada and abroad which compete with the NWT for mining investment.BackgroundThe February 27, 1995 federal budget directed the Department of Indian Affairs and Northern Development (DIAND) to proceed with a comprehensive review and amendments to northern natural resource management legislation in order “to increase revenues and ensure a fair return to the Crown.” DIAND is responsible for the administration of the Territorial Lands Act, and its regulations.The Territorial Lands Act gives the Governor-in-Council the authority to “… make regulations for the leasing of mining rights in, under or on territorial lands and the payment of royalties therefor,…”. In the NWT, the Canada Mining Regulations (CMR) provide for the disposition of mineral rights for most minerals, other than coal, petroleum and related hydrocarbons, in return for the payment of a royalty to the Crown.As part of this review of the NWT mining royalty regime, several computer mine models were developed and tax regimes in a number of jurisdictions were analyzed. Effective mining royalty rates, and the combined effective mining royalty and income tax rates were compared across the jurisdictions. The results presented in this paper are a part of the background work done in preparing a discussion paper on proposed changes to the NWT mining royalty that is expected to be released for public consultation in the very near future."

Jan 1, 1997

By N. J. Shackleton, N. A. Chapman, V. Malysiak, C. T. O’Connor

In this study, the effect of using conventional crushing and high-pressure grinding rolls (HPGR) in combination with dry or wet milling was investigated using a base-metal sulphide (BMS) sphalerite and a platinum group mineral (PGM) ore to determine how these processes affect the flotation performance. In sphalerite, irrespective of the crushing procedure (HPGR or conventional), dry milling resulted in the highest grades and recoveries of zinc, whereas in PGMs, similar treatment produced the poorest results. The results were investigated further by the effect of factors such as percentage liberation and particle size on the flotation results.

Jan 1, 2012

By Leroy G. Hagenbuch

"IntroductionAn integrated Truck Management Information System (Truck MIS) evolves as seemingly separate functions combined to yield a single homogeneous result / product. The concept of a computer integrated Truck MIS includes truck dispatch, truck maintenance management and truck weighing.A truck management system is only as good as the information / data bases input to it. The concept of an integrated system works best with automated data gathering. Automated data gathering provides timely and normally, the most accurate historical information/data bases. Data bases are, however, historical, which is a problem to be overcome in a computerized truck management information system, especially in regards to a truck dispatch system as loading sites / loading conditions and some dump site conditions continually change. As these changes occur, data base s must change as well, and thus the need for the continual update of data bases that the computer uses for a Truck MIS.For a truck dispatch system to achieve reliability / viability, dispatch decisions need to revolve around real time data gathered in an automated way. Integration of all truck management function s through automated data gathering lead s to the best over-all system.An integrated system is a combination of many different factors and is only as good as each factor / building block put in the system. With the proper building blocks, an integrated Truck MIS is very feasible - an MIS System that includes weighing, time and motion study, truck maintenance and maintenance management, as well as truck dispatch.Truck MISAn integrated Truck MIS provides for truck dispatch as the ultimate end result, a truly automated /integrated truck dispatch system (to function non-operator-dependent). The following comprises its central building blocks:-Time.- Haul Cycle Segments.Truck Status, i.e. Load on truck,- being loaded,- loaded,- unloaded,- in service,- out of service.- Vehicle Location.Loading Equipment Status.- in service,- out of service.Optional- distance travelled in each haul segment.With this data provided on a non-operator dependent basis, it is possible to build good data bases so a computer can make truck dispatch decisions. Knowing what information is needed as the central core to a good Truck MIS, how can this information be automatically gathered and fed into a central control computer?"

Jan 1, 1986

By S. Malopheyev, I. Vysotskiy, R. Kaibyshev, S. Mironov

"In this work, the effect of pre-strain rolling on the annealing behavior of friction-stir welded 6061-T6 aluminum alloy was studied. To this end, the as-welded material was rolled to 10 or 20 pct. of thickness reduction prior to the standard post-weld T6 heat treatment. Three rolling directions were the 3-mm thick sheet were considered: along the welding direction, perpendicular to the welding direction, and at the angle of 45° to the welding direction. At relatively low pre-strains (10 pct.), the annealing behavior was found to be very sensitive to the rolling path, and rolling along the welding direction was most effective in suppressing abnormal grain growth. On the other hand, increasing the pre-strains to 20 pct. of thickness reduction inhibited abnormal grain growth irrespective of the rolling path.INTRODUCTION Heat-treatable wrought Al-Mg-Si alloys are widely used due to attractive combination of strength, ductility, excellent corrosion resistance and low cost (Polmear, 2006). To provide the optimal balance of mechanical properties, these materials are typically commercially available in appropriately work- and precipitation-hardened conditions (Polmear, 2006). During conventional fusion welding, however, the prior strengthening effect is totally lost due to elimination of the work hardened structure and dissolution of the strengthening precipitations. An innovative friction-stir welding (FSW) technology may partially overcome this problem. Due to the solid-state character of this process, which involves very large strains, the welded material is characterized by fine-grained microstructure with moderate-to-high dislocation density, and thus the prior work hardening effect may be preserved or even enhanced (Threadgill et al., 2009; Mishra & Ma, 2005). However, heat input associated with FSW inevitably leads to dissolution and/or coarsening of strengthening precipitates, thus giving rise to the undesirable material softening. In an attempt to restore the strength of the friction-stir welded material, the standard T6 post-weld heat treatment has been applied, but this approach was found to lead to abnormal grain growth (Malopheyev et al., 2016; Mironov, 2013, Mironov et al., 2015)."

Jan 1, 2018

By John Jiang, Brian R. Hart, Stamen S. Dimov, Aparup Chattopadhyay, Barun K. Gorain

"This paper presents a systematic approach to metallurgy diagnostics using an integrated gold deportment methodology developed for complex refractory gold and copper-gold ore bodies. Quantification of gold deportment for these ore bodies is a challenging task due to reasons such as lower grades, high variability of visible and invisible gold content in different sulphides and iron oxide phases, significant presence of disseminated and composite carbonaceous matters along with associations of various copper sulphide phases. Some case studies are presented in this paper to demonstrate the value of a high confidence gold deportment methodology in developing insights for problem diagnostics and to identify opportunities for metallurgical improvements. A holistic approach involving different fields of expertise is critical for successful development and delivery of solutions for complex ore bodies.INTRODUCTION Studies were initiated on various complex ore deposits and also on samples representing various process streams. These complex copper-gold single refractory, double and triple refractory gold ores are mainly composed of silicates and/or carbonates with moderate amounts of clay and mica, along with minor amounts of sulphides and organic carbonaceous matter. Variable proportions of visible gold and “invisible gold” (sub-microscopic gold) were noted in different mineral phases for various ore types and process stream samples. Invisible gold commonly occurs as solid solution or as colloidal-sized particles in different sulphides and other phases for different refractory ores. The dominance of invisible gold and presence of highly preg-robbing along with finely disseminated carbonaceous matters adversely affects gold recovery in flotation and leach circuits for most of these double and triple refractory ores. This paper discusses applications of an integrated gold deportment technique developed for different types of gold and copper-gold ores, namely, complex copper-gold, double and triple refractory gold ores (Chattopadhyay & Gorain, 2014; Chattopadhyay et al., 2016). Various process streams from flotation and gold leaching circuits were investigated. Different concentrates and tailings samples from flotation circuits whereas feed and discharges from pressure oxidation (POX) and carbon-in-leach (CIL) residues were used from gold processing circuits."

Jan 1, 2017

By R. J. Labine, D. I. Brisbin, R. Roussain, P. R. Coad

"Abstract - The Owl Creek Mine is located near the west end of the Neo-archean Abitibi greenstone belt, 17 km northeast of Timmins, Ontario, and 4 km north of the Destor Porcupine fault. Gold occurs in epigenetic quartz veins and their pyritic wallrocks in two zones within a package of east striking, steeply north dipping, volcanic and sedimentary rocks. At the West Zone, 1 729 603 t of ore with a grade of 4.83 g/t Au (268 587 troy oz.) were produced from an open pit centered on a wedgeshaped unit of Tisdale Group basalt that occurs between two overturned, south facing units of Porcupine Group graywacke and argillite. Basalt/graywacke contacts are locally marked by graphiticcarbonaceous argillite, strike-parallel faults and massive quartz veins.Deformed quartz+/-ankerite veins occur along the graphitic sedimentary/volcanic contacts and in gently to moderately dipping fractures in basalts, and, to a lesser extent, in graywackes. Veins also occur sub-parallel to steeply dipping 070° foliation. Altered host basalts are composed of iron carbonate, sericite, quartz, carbon, chlorite and disseminated pyrite. Gold occurs as inclusions in pyrite, and less commonly as free gold in fractures and along graphite-quartz grain boundaries in quartz veins. Fractures preferentially developed in more competent basalts during pre- to syn-ore deformation are interpreted to have provided the permeability required for emplacement of mineralized quartz veins. Carbonaceous basalt/graywacke contacts further enhanced gold deposition by acting as chemical traps. The interaction of hydrothermal fluids with these carbonaceous sedimentary rocks led to the characteristic local darkening of host basalts due to carbon impregnation and chlorite development."

Jan 1, 1998

By G. W. Brooks

This short article is quite different to the general run of papers that are presented to the Institute, but no apology is offered because I consider that first-aid and mine-rescue work are of equal importance to many other subjects that are dealt with in our Transactions. Members of the Institute should be as much interested in the safety of persons engaged in the mining industry as they are in the practical methods of modern mining. We must not only do our best to conserve life and property by adopting every known device to that end, but we must also prepare ourselves so that we may take prompt and effective action when life is in danger, or when property is subject to loss. The need for such preparation in Alberta is perhaps greater than in most places where mining is carried on, and we must spare no effort to assemble at every mine men who are well trained in first-aid and mine-rescue work. The large area over which the mines are distributed renders central training stations out of the question, hence the need for local rescue-teams. Hospitals with skilled staffs, close enough to the mines to be convenient, also seem to be out of the question; therefore the greater need of a high standard of first-aid training for the people in our mining camps. The Government mine-rescue cars are supplied with the equipment necessary for training persons in this essential work and also for dealing with disasters should they occur. The question then arises: are there a sufficient number of men who are trained ? If so we can rest assured that what is possible to be done will be done. But if a sufficient number of trained men are not available much loss of life and damage to property is likely to result.

Jan 1, 1925

By C. H. G. Bushell, G. Brown, C. J. Krauss

1N FLOTATION, copper sulphate is used universally for the activation of sphalerite and marmatite and, to some extent, for the activation of other minerals. The copper activated surface readily adsorbs standard collectors such as the xanthates and dialkyl dithiophosphates whereas untreated zir~ sulphide does not. With the host of reagents available, making a mineral float is seldom difficult. The problem is to achieve selective flotation. In zinc flotation, the great value of copper sulphate results from its ability to activate zinc sulphide preferentially to gangue minerals. At the Sullivan Concentrator of The Consolidated Mining and Smelting Company of Canada Limited, the most abundant gangue mineral in the lead-zinc ore is pyrrhotite, and the zinc mineral is marmatite of somewhat variable zinc to iron ratio. For this Cominco study, selectivity between marmatite and pyrrhotite was therefore the most interesting aspect of copper sulphate activation.

Jan 1, 1961

By Q. Han

A modified cast-on method has been developed to reinforce aluminum castings with steel insert. Defect-free bond between the steel insert and the aluminum casting has been consistently obtained. Data obtained from a push-out experiment indicated that the bond strength was much higher than that obtained using the Al-Fin approach. This paper introduces this modified method in four sections: the coating of the steel pins, the cast-in method, microstructure characterization, and the bond strength. The section on the coating of the steel pins contains coating material selection, electro-plating technique for plating Cu and Ni on steel, and diffusion bonding of the coatings to the steel. The section on cast-in method deals with factors that affecting the quality of the metallurgical bond between the coated steel and the aluminum castings. The results of microstructure characteristics of the bonding are presented in the microstructure characterization section. A push-out experiment and the results obtained using this method is described in the section of bond strength/mechanical property.

Jan 1, 2015

By F Kelly

"A central composite experimental design was used to determine empirical relationships between the operating variables of a ball mill and the characteristics of the ground products. The independent variables selected for the study were the work index and size distribution of the feed material, the feed rate and the pulp density. The measured responses included product size distribution, product surface area, viscosity of pulp discharge, weight of dry solids in mill, mill time constant and emitted sonic vibrations. The ball mill was operated continuously in open circuit during each experimental run.Multivariable regression techniques were used to derive linear empirical models from the experimental results. Of the four factors studied, the grindability of the feed material significantly affected every measured response. The size distribution of the ground product was affected significantly by the feed rate and the size distribution of the feed, but not by the pulp• density. Feed throughput capacity and pulp density were significant to the viscosity of the pulp discharge, the weight of solids in the mill and the mill time constant. Significant first-and second-order models are given for the above relationships. The relation-ships between the characteristics of the sonic vibrations of the operating mill and the various dependent variables have not as yet been established."

Jan 1, 1970

By D. S. Flett, A. V. Tolstov, M. A. Mulagaleeva, N. V. Gudkova, A. M. Zhizhaev, V. I. Kuzmin, Institute of Chemistry and Chemical Technology SB RAS, O. A. Logutenko, V. N. Kuzmina

The complex niobium-rare earth pyrochlore-monazite-crandallite ores of the Tomtor deposit, located in the Siberian Arctic, should be considered as a new type of rare metal materials. The major valuable components of the ore are niobium, rare earth elements, yttrium, and scandium; associated components are titanium, vanadium, aluminum, and phosphorus. Because of the irregular distribution of the rare earth metals and niobium according to grain-size, the extremely finely dispersed nature of the minerals and their close interpenetration to each other, ore processing by gravitation and flotation is not successful. The processes studied for the treatment of the Tomtor ores use direct alkaline-acid leaching to open the ore. A problem in the first stage of alkaline leaching is the high aluminum content, which decreases the activity of sodium hydroxide and alkaline-earth metals, which are bound to phosphorus. Ore processing using alkaline-nitrate and alkaline-chloride leaching was proposed and investigated. The first variant was used to obtain rare earth and scandium materials and a niobium-titanium concentrate, which can be a stock material for processors who use chlorination for the processing of ores and concentrates. The second variant is a complex advanced ore processing scheme with electrochemical regeneration of the waste chloride solutions obtaining sodium hydroxide, hydrochloric acid, and chloridizing agents. Moreover trisodium phosphate is used for purification of the waste mother liquors from metal cations. The complex salt, NaAlCl4, is proposed as the chloridizing agent for the decomposition of the niobium-titanium concentrate.

Jan 1, 2016