Search Documents

By S. Steinlechner, G. Schneeberger, J. Antrekowitsch

The recycling of steel mill dusts is getting more and more important. The costs and requirements of land filling are rising and companies are interested in new recycling strategies. The rising of sustaina¬bility hand in hand with the high rate of valuable metals in these residues supports new research activities on the recycling sector. Especially zinc but also iron and lead are economical factors due to the treatment of steel mill dusts. This paper gives a small overview of fundamental studies concerning the chemical and physical composition of these dusts. Furthermore aggregates for the reduction of these dusts in the liquid phase are introduced and compared. The Flash-Reactor, the TBRC-Technology (Top Blown Rotary Converter) and submerged arc furnaces and there use for melting and treatment of these dusts are in the center of interest of this paper. The final conclusion gives an overview of possibilities for reduction of filter dusts in the liquid phase.

Jan 1, 2011

By Xiong Tong, Jiushuai Deng, Yingbo Mao, Lingyun Huang

Ammonium carbamate has been used as a reagent for the leaching of copper from the copper oxide ore found in the Honghe state, Yunnan province, China. In order to find the optimal conditions for the leaching of copper from this copper oxide ore,the effects of several processing parameters, including the concentration, time, temperature, particle size and stirring intensity have been investigated. The results of these optimization experiments showed that the leaching rate of copper reached up to 72.76% under the following conditions: liquid-to-solid ratio of 10:1, ammonium carbamate concentration of 2.5mol/L, leaching temperature of 45 °C, stirring speed of 300rpm, a reaction time of 1.5 h and 85% by weight thereof passes through a sieve having 0.074 mm.

Jan 1, 2015

By M. Sengupta, A. A. de Gast

"With rapid deterioration in the urban environment caused by air pollution, the possibility of chemical reaction between dimension stone and the industrial waste gases present in the ambient atmosphere remains. The chemical reaction can cause expensive damage to building stone; it is essential that a stone evaluation for use in construction should assess the possibility of this type of decay. This paper endeavours to develop testing procedures for evaluating stone decay in polluted environments. Such tests can accompany other standard tests used in dimension- stone evaluation."

Jan 1, 1972

By D. G. Crosby

This paper defines the Canadian offshore areas, comparing the juridical continental shelf with the physical one. The question of jurisdiction and ownership is dealt with, and the setting out of resource administration lines to divide areas of federal and provincial administration is explained and illustrated. Offshore activity is reviewed and prospective areas for future work are mentioned.

Jan 1, 1969

By W. J. Tough

THIS paper offers examples of some of the typical calculations which occur in the ventilation of metal mines. The fi.rst section of the paper discusses the problems associated with natural-draft pressure; the second section presents the more common of the calculations concerned with the operation of mine fans; the third section illustrates the integration of the individual problems covered by the preceding sections into the larger problem of determining the operating characteristics of a fan for a particular mine duty. There is a very definite limit to the extent to which pure arithmetic can be successfully applied to the solution of min<; ventilation problems. As mines advance from the exploration, development, and initial production stage to the rime when underground workings become exceedingly complex, there is a considerable increase in the relative importance o theory and judgment in the solution of ventilation problems. These calculations illustrate the application of mathematics to ventilation, but they also in-elude examples of instances where arithmetic cannot be conveniently applied, and important estimates, based on judgment compounded of experience and a knowledge of the theoretical consideration involved, must be made. The inclusion of such estimates is intended as a guide and a warning to the reader; a guide in assisting him to recognize and estimate his own incalculables; and a warning that the solutions must not be blindly applied to his apparently similar problems. These sample calculations are intended to assist the reader in applying the theory contained in the standard texts on metal-mine ventilation. They have been selected from the ventilation experience of a British Columbia mine.

Jan 1, 1942

"Real-time, on belt analysis of minerals is becoming increasingly important and critical in modern operations, especially in the mine-to-mill. Prompt gamma neutron activation analysis has long been utilised for real-time elemental analysis in bulk materials, with Scantech's GEOSCAN being the instrument of choice in the minerals sector. Working in the minerals space for 15 years, the GEOSCAN has been successfully implemented in a wide range of minerals applications including iron, copper, lead-zinc, manganese, phosphate and more, and it caters for the very high demands and increasing requirements of a contemporary processing facility. An area of focus has been on increasing the analysis frequency to allow for rapid analysis results with the same high degree of accuracy typically expected of the GEOSCAN. This paper discusses the underlying research and technology that has enabled such rapid analysis and presents a range of examples using a thorough statistical approach on real production material, demonstrating achievable accuracy over a short analysis time, and dispelling common myths about the speed of the technique. Potential applications are discussed to conclude the paper.INTRODUCTION Technology and the information it can provide plays a critical role in the evolving modern mineral processing landscape. The importance of technology to analyse various features of ores and concentrates being processed is obvious, and recent years has seen the advance of numerous technologies to provide a variety of real-time measurements on conveyed material flows. From sampling apparatus to particle size analysis to weight and density meters to full elemental analysis, the availability of information enables a variety of improvements in the process leading to improved efficiency and increased revenue. To maximise the potential benefits, access to real-time information is imperative, and rapid updates of information become necessary to make appropriate process control decisions based on the most relevant and up-to-date information."

Jan 1, 2017

By S. R. Stopic

The EU-financed INTREAT Project (Integrated treatment of industrial wastes to¬wards prevention of regional water resources contamination) addresses the environmental pollution associated with solid and liquid wastes/effluents produced by complex sulphide ore mining and metallurgical activities. The results concerning the electrolytic recovery of cop¬per from effluents formed after mixing of streams from Copper Refining, Precious Metals Plant and Electrolyte Regeneration in the Balkan Area will be shown. The waste water is characterized by low pH values and high contents of heavy metals, such as Cu, Ni, Bi, As, Sb. The majority of these waste water flow untreated into the natural water streams and through the network of existing rivers, which end up in the river Danube. The influence of current density and flow rate on the deposition rate, the quality of copper and the process efficiency will be presented. The full continuous process is based on cells with rotating disc cathodes and represents a pre-treatment step before common neutralisation in a cascade line

Jan 1, 2007

By E. V. Konopleva, H. J. McQueen

"The isothermal bainite transformation kinetics of low- and medium-carbon alloy steels after hot deformation and the rmocycling treatment (TC) has been studied by the magneto - metric method. Deformation was produced by rolling at 800°C-1000°C. TC included three cycles of rapid (30°C/s) electro-heating up to 900°C-1000°C followed by quenching.Hot deformation retards bainite transformation in the lower part of bainite range (<400°C) and accelerates it in the upper part (>400°C). The effect is greater for higher strain and lower deformation temperature. Deformation also diminishes the overall bainite fraction below 400°C and increases the completeness of reaction above 400°C.Thermocycling provides more uniform ultrafine austenite grains with average size of 3 µm -4 µm compared to 12 µm -14 µm after conventional heating. The transformation rate after TC was almost the same as after conventional heating in low-carbon steel but was faster in medium-carbon with no change in the completeness of reaction. The degree of acceleration increased with rise of transformation temperature.There are a number of factors which are responsible for a change in bainite transformation kinetics in austenite deformed at high temperatures or subjected to TC. One of the most important factors is the refinement of structure, another one is structural and chemical inhomogenity of austenite due to deformation or to rapid heating. To estimate the contribution of these factors, ?-transformation was studied after different austenitizing conditions (low-temperature heating at 850°C- 950°C; high-temperature heating at 1100°C; step treatment – austenitizing at 1100°C, then cooling to 950°C-850°C). The results obtained make it possible to conclude that the structural and chemical inhomogeneity of austenite activate the bainite reaction while the grain refinement retards it. Intensity of the effect produced by each factor depends strongly on the steel composition."

Jan 1, 1997

By H. E. Miard

"IntroductionIT HAS BEEN SAID, with good reason, that the future of the coal mining industry, in our mountainous regions at least, depends on ability to extend operations successfully to depths greater than those reached until now. However, at many points, Nature has given definite hints that trespassing there could be fraught with very un-pleasant possibilities, unless the intruder be governed by a series of rigidly observed principles. In the coal mines of British Columbia, so far, bumps have taken place only at the Coal Creek colliery, but there they gave ample evidence of the extent to which they can hamper underground operations. Some of these manifestations have also been experienced at the McGillivray Creek colliery, in Alberta, at Carbonado, in Washington, and at Sunnyside, in Utah.Cognate phenomena, known as 'air blasts', have been experienced also in some deep metalliferous mines in British Columbia. Such occurrences were responsible for three fatal accidents at the Le Roi and War Eagle mines, near Rossland, in 1916 and 1917.In more or less disturbed coal fields, another form of stress release, equally detrimental, has been still more generally experienced than have been the bumps. Coal outbursts have taken place at Morrissey and Coal Creek, in the Crow's Nest Pass district, and at Cassidy, South Wellington, and the Nanaimo Reserve colliery, on Vancouver island. Manifestations of this kind have been made the subject of intensive study in European countries where they occurred on a really impressive scale, which must not be construed as meaning that some of our own outbursts did not approach a comparable magnitude."

Jan 1, 1953

By T. Feldmann, G. P. Demopoulos

The adsorption of gold complexes on inorganic metal oxides has been mainly discussed in geochemical literature, but it is also of interest to the hydrometallurgical industry. This is so because it could be responsible for valuable metal losses or because it could potentially serve as alternative adsorbent material to activated carbon in certain cases such as from hot and acidic process slurries. This paper constitutes an early investigation into this subject by focusing on the effectiveness of FeOOH, Fe3O4 and Al2O3 as sorbent materials. All tests were done in a batch stirred-tank reactor under atmospheric conditions with synthetic gold(III)-chloride solutions at 23°C and 80°C, in the pH range of 1.6 to 9.0. Detailed kinetic tests were performed at different pH values (3 and 6) on FeOOH and Fe3O4 with solutions having gold concentrations from 5 mg/L to 130 mg/L. The adsorption of gold was found to be best both in terms of kinetics and loading characteristics at 80°C and pH=6. This was explained by a change in Au(III)-Cl speciation from a gold(III)-chloride complex to a gold(III)-chloride-hydroxy complex. By far, magnetite (reagent grade chemical) yielded the best gold adsorption characteristics making it an interesting sorbent material for further development considering that it can be advantageously recovered from slurry streams via magnetic separation. On the other hand, the tendency of gold(III)-chloro complexes to adsorb on metal (hydro) oxides needs to be taken into account to minimize undesirable metal losses in chloride-containing leaching media.

Jan 1, 2015

By G. M. Card, K. D. Card, B. V. Sanford

Abstract-The Canadian Shield and its extensions are traversed by an orthogonal system of northwest and northeast trending arch-style uplifts. These basement arches were formed by repeated vertical movements along pre-existing structures during compressional and extensional tectonism connected with events in surrounding Proterozoic and Phanerozoic orogens and ocean basins. The arches influenced patterns of sedimentation and tectonism in the intervening epicratonic basins and marginal platforms throughout the Proterozoic and Phanerozoic. Movements on the arch structures also triggered minor magmatism and controlled the location and timing of alkalic rock-carbonatite, kimberlite, and related intrusions in the Canadian Shield, the Western Canada Sedimentary Basin, and West Greenland.

Jan 1, 1997

By G. M. Card, K. D. Card, B. V. Sanford

The Canadian Shield and its extensions are traversed by an orthogonal system of north-west and northeast trending arch-style uplifts. These basement arches were formed by repeated vertical movements along pre-existing structures during compressional and extensional tectonism connected with events in surrounding Proterozoic and Phanerozoic orogens and ocean basins. The arches in?uenced patterns of sedimentation and tectonism in the intervening epicratonic basins andmarginal platforms throughout the Proterozoic and Phanerozoic. Movements on the arch structuresalso triggered minor magmatism and controlled the location and timing of alkalic rock-carbonatite, kimberlite, and related intrusions in the Canadian Shield, the Western Canada Sedimentary Basin, and West Greenland.

Jan 1, 1997

By Patrick Wong, Gareth Hatch, M. A. Halim, V. I. Lakshmanan, Darcy Tait

"This paper describes development of an integrated chloride process for separation and purification of REEs. The process includes atmospheric leaching of ore/concentrate with mixed chloride lixiviant containing HCl and MgCl2 followed by bulk recovery of REEs, dissolution of the bulk intermediate product, and separation of individual REEs by solvent extraction (SX) process steps. Mixed chloride leaching technology provides the opportunity to regenerate the lixiviant, while the addition of MgCl2 in HCl enhances the hydrogen ion activity by orders of magnitude increasing REE extraction efficiency at a lower concentration of HCl. An individual REE separation process developed by Innovation Metals Corp. is being piloted at a state-of-the-art facility at Process Research ORTECH Inc. in Mississauga, Ontario, Canada. The SX process includes the separation of light REEs (La – Nd), medium REEs (Sm – Gd) and heavy REEs (Tb – Lu plus Y) from leach liquor followed by individual REE separation. Each SX circuit proceeds by multistage extraction followed by scrubbing and stripping. The process is chloride based and reagents are recycled, reducing waste generation and optimizing water usage to reduce environmental impact.INTRODUCTIONRare earth elements (La to Lu plus Y) exhibit a range of unique magnetic, electronic, catalytic and optical properties. Due to these special properties, the application of REEs is increasing and they are found in components for wind power generation, hybrid electric cars, catalytic converters, and many electronic devices.Rare earth elements (REEs) are commonly divided in two groups: light rare earth elements (LREEs) and heavy rare earth elements (HREEs). Light rare earth elements include elements from lanthanum (La) to neodymium (Nd). Although promethium (Pm) is considered an LREE it is unstable and scarcely occurs in nature and is generally excluded. Heavy rare earth elements include elements from samarium (Sm) to lutetium (Lu) plus yttrium. Although rare earth elements are not rare and the rare earth oxides are scattered around the globe, over 95% of REEs+Y are currently produced in China (Pitts, 2011). On one hand the Chinese government is restricting the export of rare earth elements and on the other hand the demand for REEs+Y is increasing in the rest of the world. This has created an imbalance in the supply and demand of rare earth elements and has led to a rush for developing new rare earth projects."

Jan 1, 2016

By H. H. Bleakney

The merit of reduction-in-area as a criterion of quality in metals is shown to lie in its influence on breaking stress, but the virtue of elongation is not easy to find. In order to assess the value of elongation, either as a measure of quality or as a guide to design, it will be necessary to separate the overall de-formation occurring in tension tests from the localized deformation associated with localized reduction in area. The obstacles to a successful solution of this problem have been shown to be more formidable than is generally appreciated, and a new solution to the problem has been suggested. This solution involves a de-vice by which an electric circuit is broken when the particular value of strain is reached that is to be taken as the point of separation between general and localized deformation. The report presents results from a number of tests on both low-carbon and alloy steels. These results indicate that the selected criterion of separation is accurately identified by the proposed method; that it

Jan 1, 1962

By J-L. Tang

A new rhcoforming processing of Al alloys with component shaping systems apart from slurry preparation systems is experimentally exploited, using the reversible multilevel-speed electromagnetic stirrer, the slurry transfer tool and its coating, the thin plate sample with five steps and rheocasting mould, all of which are independently developed. The results show that semi-solid A356 alloy slurry with shape factor of about 0.85 and particle size of 70~80 µm (under air-cooling condition) could be prepared in 20~25 s, fully meeting the production rate of high pressure die casting. The slurry could be smoothly transferred from the slurry preparation equipment to the rheocasting shot chamber while the slurry temperature of slurry decreases by no more than 3 . The tensile strength and elongation of the semi-solid rheocasting samples could be respectively increased by 11.6~18.2 % and 42.5~50 % compared with the traditional liquid die casting ones, and the rheoforming processing has close affinity with the traditional hot working processes.

Jan 1, 2007

By D. J. MacKinnon

"The Canadian Copper Company, formed in 1885, began mining the nickel-copper ores of Sudbury in 1887 and producing nickel-copper matte from its smelter in 1888(1). Although it was quickly appreciated that the separation of nickel and copper (i.e. refining) was critical to the production of a marketable nickel product, refined nickel was not produced in Canada until about 1918. From the beginning of the industry, there was considerable political agitation to refine nickel in the Province of Ontario(2). The companies, however, claimed that the existing processes, viz. the sodium sulphide ""tops and bottoms"" process operated by the Orford Copper Company of New Jersey, U.S.A.(1,3,4) and the carbonyl process(5,6) developed by the Mond Company at Clydach, Wales, were too costly to operate in Canada. Nickel was first refined in Ontario about 1918 when the International Nickel Company opened a nickel refinery at Port Colborne, Ontario(6). Initially, however, the refinery at Port Colborne employed the Orford sodium sulphide process, and the first electrorefined nickel in Canada was produced in 1920 by the British America Nickel Corporation whose mine and smelter were located in Sudbury, Ontario, but whose electrorefinery was located at Deschenes, Quebec, near Ottawa, Ontario. The purpose of this article is to outline the early history of nickel electrorefining and to trace the significant developments which led to the first successful commercial electrolytic nickel refinery in Canada. The development of an electrolytic process for refining nickel is due largely to the efforts of four individuals, viz. Carl Hoepfner, Hans A. Frasch, D.H. Browne and ultimately N.V. Hybinette, and the contribution of each is discussed separately below."

Jan 1, 1999

By R. H. Wallis

Weighted moving-average contour maps have been constructed for molybdenum, copper and zinc using 7850 stream-sediment samples from 5430 square miles (14,063 sq. kms) of south-central British Columbia. Regional trends for molybdenum and zinc are northeast, north and northwest and those for copper are north and northwest. These trends are interrupted by zones markedly low in metals . The metal-rich trends cross rocks of different lithology and age and thus appear to be structurally controlled. The northeast trend may have exerted control on metal distribution at two different times.

Jan 1, 1978

By A. L. McAllister

"MASSIVE sulphide deposits are found in two areas of New Brunswick, the St. Stephen area and the Bathurst-Newcastle area. In both, the geology in the immediate vicinity of the sulphide bodies is largely inferred from drilling results as outcrop is not plentiful and is, in fact, almost lacking in most places. With few exceptions these deposits have not been explored by underground methods. Consequently much of the. detail on the geology will only become known over a period of years as economic conditions make mining feasible.Much of the information contained in this paper has been supplied directly by company geologists. As a result of the number of contributors, some confusion of nomenclature bas to be anticipated. Cross-sections and plans of the individual deposits are, in most cases, as supplied by the companies concerned. Most of the interpretations are the responsibility of the author."

Jan 1, 1960

By S. Kelebek, U. Demir, T. C. H. Richards, E. Koss

"Laboratory-scale tests were carried out to investigate the response of a high-grade (~143 g/tonne) well-liberated gold ore to flotation using two collector types. Octyl and amyl xanthates, representing conventional types of collectors, were tested against an n-octanoic and hexanoic acids under moderate and high redox potential conditions. The latter was based upon a suggestion in literature that monocarboxylic acids are able to adsorb onto the surface of gold at redox potentials near 600 mV (SCE). This investigation did not demonstrate that these carboxylic acids could function as collectors for gold in real ores. In fact, they appear to have slightly depressed gold. However, the results demonstrated that octyl and amyl xanthates acted as highly effective gold collectors for this ore and that an increase in the collector dosage led to an increase in recovery for all mean particle sizes. In some tests, gold recoveries of around 95% were attainable in concentrates with grades around 6 kg/tonne, indicating that xanthate flotation remains a viable means of concentrating gold even at coarse grain sizes. Various aspects of the process such as grade-recovery performance and recovery by size are discussed.INTRODUCTION Three methods are used for the recovery of gold in mineral processing, either alone or in combination: gravity concentration, cyanidation and flotation. Gold occurs as a by-product in some ores together with platinum group metals and as the primary metal in other ores in the form of native gold and electrum, which are alloys of gold, silver and minor amounts of copper. Flotation is a viable method for recovering liberated gold where the gold is visible under an optical microscope (greater than 1 µm in size) and where the attachment of gold grains is not prevented due to bubble loading by competing minerals. It is generally known that grains finer than 150 µm in size will float with most collectors."

Jan 1, 2017

By Xueyuan Nie, Xuezhi Zhang, Henry Hu, Shen Xinwei, Jimi Tjong, Li Fang

With the demand for weight reduction in vehicles and airplanes, researchers have shown great interested in casting wrought aluminum alloy 7075 because of its potential advantages such as high strength-to-density ratio and stress-reduction capabilities. It is therefore essential to conduct a fundamental investigation on solidification behavior and grain microstructure of alloy 7075. In this study, a commercially-available wrought aluminum alloy 7075 was used to study the solidification behavior of alloy 7075. A thermal analysis was performed based on the cooling curve and its corresponding first and second derivative curves. The nucleation of the primary a-Al phase and eutectic phases were analyzed. The comparison between the microstructures of the wrought and cast 7075 alloys shows that coarse microstructure and porosity are present in the cast alloy. The techniques for grain refinement in casting, such as the addition of the nucleating particles and applied pressure, should be employed to reduce the dendrite arm spacing and the porosity.

Jan 1, 2015