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By Jasmin Raymond

Ground source heat pumps are used to heat or cool building and heat water supply. Such heat pumps use the earth as a heat source or sink to efficiently provide or store thermal energy. For example, a ground source heat pump typically requires less then a third of the electric or fossil fuel energy of a conventional heater. Ground source heat pumps could therefore help reduce the energy consumption of active mines where low-grade geothermal resources are abundant. In most heat pumps, water or a water-antifreeze mixture having a temperature ranging from -6.5 to 43.5 °C is circulated through a heat exchanger at a rate of 0.000033 to 0.000067 m3/s (2 to 4 L/min) for each kilowatt of heating/cooling capacity. The groundwater that is continuously pumped to drain mines could be used to operate heat pumps. Water feeding a heat pump can alternatively circulate in a close loop network of pipes buried underground or installed in a surface water body. Retention water ponds, tailings and waste dumps commonly found at active mine sites could provide excellent environments to install the close loop system. Further research will help take advantage of the unexploited geothermal resources associated with actives mines.

May 1, 2007

By C. Juers

Laboratory chromate coating was applied on AM50 and AZ91D alloys and compared to phosphate-permanganate one. Evaluation of the corrosion behaviour was performed using electrochemical DC and AC methods in ASTM water D1384-87. This electrolyte was chosen because it was moderately aggressive and found to give generally good correlations with long period exposure results in atmospheric conditions. Electrochemical impedance spectroscopy was used to determine more accurately the corrosion rates from the analyses of the high frequency capacitive loop. Anodic polarization was applied in order to evaluate the pitting resistance of the different coatings. These results were correlated with weight loss data evaluated from experiments performed by immersion tests in ASTM water D1384-87 and climatic cyclic chamber tests.

Jan 1, 2006

By R. M. Young

In. East Kootenay, two Companies are operating, the Crow's Nest Pass Coal Company of Fernie, with mines at Coal Creek and Michel, and the Corbin Coal and Coke Company, of Corbin and Spokane. Wash., with mines at Corbin. The Crow's Nest Pass Coal Company has also coke-ovens of the bee-hive type at Fernie and Michel. The mines have a productive capacity, with present development and plant, of approximately 1,500,000 tons of coal, and of 300,000 tons of coke annually. The total production in 1923 was 828, 990 tons of coal and 65.990 tons of coke. In the early years of operation, the mines furnished a very large percentage of their output to the railways and smelters. These were, in fact, the primary markets for which the mines were opened and the ovens constructed. The Great Northern Railway had built into Femie, and later extending its line to Michel, became a heavy consumer of both of these mines. The Spokane International, connecting the Crow's Nest branch of the C.P .R. with Spokane, furnished tonnage to Corbin. The Canadian Pacific Railway bought for Crow's Nest consumption. The smelters at Grand Forks and Trail in the Boundary country were large and steady consumers of coke, while in-termittently Northport, Butte, Helena, and Great Falls shared in the product of the ovens.

Jan 1, 1924

By B. W. Snyder

INTRODUCTORY THE earliest known case of transmission of natural gas by pipe lines was early in the Christian era when the Chinese used bamboo pipes to transport natural gas from surface seepages to heat brine for the recovery of salt. Since that time many materials have been used as conduits-hollow wooden legs, wood stave pipe, day tile, cast iron, and, finally -since about 130 years ago - steel pipe. Even then, this new material came into use rather . slowly for, as recently as 80 years ago, wood pipe was still being used. However, as techniques were developed to take advantage of the properties of steel, this material gradually replaced all ethers for the transportation of gas for longer and longer distances at ever increasing pressures. In 1912, one of the longest pipe lines of its size at that time was built-this was a 16-inch line bringing gas from Bow Island to Calgary, a distance of 170 miles. We have been able to find records of only two ether such lines at that time-one a 185-mile 16-inch line from Vivian, Louisiana, to Little Rock, Arkansas, completed in the summer of 1911, the ether a 280-mile line from West Virginia to Toledo, Ohio. This last ? mentioned line was reported in a magazine article of September, 1912, but no indication was given of its size on completion date. It is apparent, therefore, that modern high pressure transmission of natural gas is a technique less than forty years old.

Jan 1, 1951

By H. W. Leon, F. J. Ellis

"This paper covers the new six-strand curved-mould billet casting machine at the Contrecoeur Works of SidbecDosco. It commenced production of 3 Yz-in. square billets at the beginning of January 1972. Together with two 100- ton ultra-high-power electric furnaces in a new meltshop, it is the principal source of billets for the existing rod and bar mill also located at Contrecoeur. The paper develops the reasoning for casting-to-size 3Y2 -in. billets and for choosing a six-strand machine. It indicates the significance of Sidbec-Dosco Montreal Works' extensive experience in operating a four-strand curvedmould billet machine since 1965 and the ways in which this experience influenced the design and operation of the new caster. Machine features are described in detail, as are the reasons for some of the features. The installation, checkout and crew training are briefly discussed as well as the tundish teeming trials. The first cast on January 5, 1972, is covered and a log is shown of the first casts to an empty ladle. There are operating statistics covering the first 100 casts, which produced 8000 tons of good billets in ten weeks of operation. Machine performance and billet quality were good and the few minor problems encountered are described."

Jan 1, 1973

By Peter M. Power

A microscopic study was made of a series of simultaneous slag and metal samples taken from a low carbon basic open hearth heat. An attempt was made to identify the various micro-constituents found. As the various impurities in the bath are oxidized, the metal structure changes from that of high-phosphorus white cast iron to that of low.-carbon steel. A detailed study of phosphorus distribution is included. The acid run-off slag has an .acicular orthosilicate structure which changes on 'shape-up' to a very basic tri-calcium silicate and calciuim ferrite structure. Many unidentified minor constituents are present in the slags. Though metallography will never replace chemic.al analysis of the bath, the microsopic study of polished slags has some promise of being useful in slag control work.

Jan 1, 1956

By M. A. Rabah

This study aims to recover europium, yttrium metals, some valuable salts or oxides from the white powder (apatite) coating the inner surface of spent florescent lamps (SFLs). Pressure leaching using sulphuric/nitric acid successfully dissolved the metals of interest. Europium or yttrium metals were obtained by hydrogen reduction of their oxides. Addition of potassium thiocyanate converted the dissolved sulphates to thiocyanates. Selective separation of Eu and Y was then carried out by solvent extraction from the thiocyanate solution. The used solvent was trimethyl-benzylammonium chloride. N-trihutylphosphate in 1 M nitric acid was used to strip the metal loaded in the organic phase. Results showed that the quality of the cleaned glass tubes of the SFL met the standard requirement for the lamp manufacture. The white powder (WP) is composed of calcium sulphate 35.2%, phosphate 61.5% and oxides of europium and yttrium 1.65%wt. respectively. Autoclave digestion of the WP for 4 h at 120°C and 500 kPa in sulphuric acid/nitric acid mixture dissolved 96.4% of yttrium and 92.8% of europium. The conversion rate of sulphate to thiocyanate was favoured at low temperature. Stripping of Eu and Y from the loaded organic phase behaved in an opposite way. A metal separation factor of 9.4 was obtained. ate recovered europium and yttrium salts were selectively separated using ethyl alcohol or dilute nitric acid. Yttrium was very soluble while europium was not. Europium and yttrium metals were obtained by hydrogen gas reduction at 850°C and 1575°C respectively.

Jan 1, 2004

By J. E. Nesset

"This paper discusses the importance of considering residence time distribution (RTD) in the design of flotation and mixing circuits and in the analysis of operating problems. The experiences and successes of Brunswick Mining in this area are covered and include: the development of a practical RTD measurement technique using pulp conductivity, baffle installation to improve the RTD of existing process equipment, and the method in which RTD considerations have been used to design the newest flotation and conditioning operations IntroductionThe use of residence time distributions (RTDs) in the design and analysis of unit operations is well understood by the chemical engineering profession in while mineral processing engineers have tended to rely on empirical and rule-of-thumb factors. For example, in scale up from laboratory and pilot test results to full size flotation plant design, empirical rule s are often used to establish residence time and number of cells in the bank. Coleman suggests a factor of at least 2, and up to 5 for gold ores, be applied to laboratory determined flotation times. This is further illustrated in Table I, taken from Denver equipment. The number of cells in series to achieve the required retention time while minimizing short-circuiting has generated a variety of conclusions (Table 2). Obviously there is less than complete agreement on the subject. Young notes that a clear difference of opinion has emerged and cites as extremes, (i) the publications of Outokumpum showing unimpaired recovery for its largest machines (38 m3) compared to equivalent retention times for numerous smaller machines, and (ii) the experiences of Eastern European countries where the practice is to install banks of 30 unit s or more, operating in series, often with unit retention times of only a fraction of a minute.The empirical factors used by engineers presumably account for other than tested feed conditions, inefficiencies in large continuous machines, inevitable day-to-day circuit disruptions, gradual equipment deterioration and any other safety factor the engineer feels compelled to incorporate. An understanding of RTD concepts and techniques should help the practicing mineral engineer to develop more soundly based factors. Thi s paper relates the experiences of Brunswick Mining in using RTD techniques in the unit operations of flot ation and mixing"

Jan 1, 1988

By J. E. Nesset

"This paper discusses the importance of considering residence time distribution (RTD) in the design of flotation and mixing circuits and in the analysis of operating problems. The experiences and successes of Brunswick Mining in this area are covered and include: the development of a practical RTD measurement technique using pulp conductivity, baffle installation to improve the RTD of existing process equipment, and the method in which RTD considerations have been used to design the newest flotation and conditioning operations. IntroductionThe use of residence time distributions (RTDs) in the design and analysis of unit operations is well understood by the chemical engineering profession in while mineral processing engineers have tended to rely on empirical and rule-of-thumb factors. For example, in scale up from laboratory and pilot test results to full size flotation plant design, empirical rule s are often used to establish residence time and number of cells in the bank. Coleman suggests a factor of at least 2, and up to 5 for gold ores, be applied to laboratory determined flotation times. This is further illustrated in Table I, taken from Denver equipment.The number of cells in series to achieve the required retention time while minimizing short-circuiting has generated a variety of conclusions (Table 2). Obviously there is less than complete agreement on the subject. Young notes that a clear difference of opinion has emerged and cites as extremes, (i) the publications of Outokumpum showing unimpaired recovery for its largest machines (38 m3) compared to equivalent retention times for numerous smaller machines, and (ii) the experiences of Eastern European countries where the practice is to install banks of 30 unit s or more, operating in series, often with unit retention times of only a fraction of a minute.The empirical factors used by engineers presumably account for other than tested feed conditions, inefficiencies in large continuous machines, inevitable day-to-day circuit disruptions, gradual equipment deterioration and any other safety factor the engineer feels compelled to incorporate. An understanding of RTD concepts and techniques should help the practicing mineral engineer to develop more soundly based factors. This paper relates the experiences of Brunswick Mining in using RTD techniques in the unit operations of flotation and mixing."

Jan 1, 1988

By K. Östcrdahl

We are developing a cost-saving and environmentally friendly process with low energy consumption to recover the metal content and recycle the acid from spent pickle baths. The metals are precipitated as metal fluorides, which can be turned into metal oxides and hydrofluoric acid by thermal hydrolysis. In the proposed process the solution is concentrated by nanofiltration and the metals are precipitated in a subsequent crystallization step. Different nanofiltration membranes have been evaluated in experimental batch tests. The membrane MPF-34 from Koch Membrane Systems offered both good flux and acceptable metal retention even after long periods of acid storage. The solubility of B-FeF3.3H20 has been measured at varying acid concentrations and at different temperatures. The solubility decreases with increasing hydrofluoric acid and nitric acid concentrations. This suggests that the crystallization process should be operated at high acid concentrations. The crystal growth rate of B-FeF3.3H2O is found to be quite low but increases significantly with temperature. This suggests that the crystallization process should be operated at higher temperatures (40 - 60°C). Within the project a pilot plant has been constructed where the spent pickle bath solution is concentrated by nanofiltration to the desired metal fluoride supersaturation, and B-FeF3.3H2O is crystallized in a 10 L continuous crystallizer.

Jan 1, 2006

By J. Jin, J. D. Miller

"Bubble attachment at hydrophobic surfaces is of critical importance in the flotation recovery of mineral resources and fundamental experimental results have been reported in the literature describing the details of film thinning, rupture, and displacement. Now, for the first time, bubble attachment phenomena are examined using Molecular Dynamics Simulations (MDS). The simulation involves a nitrogen bubble containing 906 nitrogen molecules in a water phase with 74,000 water molecules at the hydrophobic molybdenite (001) surface. During the simulation period of 1 ns, film rupture occurs and the nitrogen bubble attaches to the molybdenite (001) surface, resulting in a contact angle of about 90o. In contrast, the film is stable at the hydrophilic quartz (001) surface and the bubble does not attach. Contact angles, determined from MD simulation after stabilization of the three phase line of contact, are reported and these results agree well with experimental and MDS sessile drop results. In this way, film stability and bubble attachment are described with respect to interfacial water structure for surfaces of different polarity. For example, the interfacial water molecules for the hydrophobic molybdenite (001) surface have relatively weak interactions with the surface when compared to the hydrophilic quartz (001) surface, as revealed bythe presence of a 3 A water exclusion zone at the molybdenite/water interface. INTRODUCTIONAttachment of air bubbles to mineral particles is of fundamental importance in understanding flotation separation phenomena. It is well known that attachment of an air bubble at a hydrophobic surface includes film thinning, film rupture, and film displacement (Somasundaran, 2006; Wilson, Adlard, Cooke, & Poole, 2000). Experimental techniques, such as high speed video, can catch the process of bubble attachment at a mineral surface (Drelich & Miller, 2012; Niecikowska, Krasowska, Ralston, & Malysa, 2012). However, molecular scale information to examine the phenomena has not yet been reported."

Jan 1, 2016

By M. Mai Manga, M. Renaud, A. Faucher, C. Bazin

ABSTRACT Grinding circuits are operated in the presence of disturbances resulting from ore changes and equipment malfunctions, such as hydrocyclone overloading, worn or partly plugged apexes, surging, and internal liner detachment that may cause a loss of classification performance. Metal recovery losses in downstream leaching or flotation circuits justify the development of methods for rapid detection of hydrocyclone malfunction. Two methods are presented in this paper. The first method uses measurements from sensors available in a grinding circuit and the second uses vibration sensors installed on the individual hydrocyclones of a nest.

Jan 1, 2011

By L. R. Wilkinson, W. J. Howarth, G. J. Wenk

Over a period of three years, a cooperative program in Australia has resulted in the development of radioisotope immersion probes for the on-stream analysis of mineral slurries. Two basic probe types are now available on a commercial basis - fluorescence and absorption probes - and within each type there are a number of variations so that optimum sensitivities can be obtained for elements with atomic number greater than titanium (22), thus covering most metals of interest to modern metallurgy.

Jan 1, 1973

By C. E. Ells

Current knowledge of the behaviour of inert gases in metals is reviewed, with particular emphasis given to the phenomenon of the growth of gas-filled bubbles.

Jan 1, 1960

By E. S. Moore

To properly understand industrial conditions in Spain it is necessary to consider the early history of the country. Spain is very backward in many lines. They use the sickle for cutting grain, and plows for cultivating the land, which resemble those of Biblical days. In the great mining camp at Bilbao only one steam-shovel is in use, although about two hundred million tons of ore has been produced, and this almost entirely from open cuts. It is the lack of industrial development, such as is found in many other countries, which permits large mining enterprises to be controlled almost entirely by foreign capital, although Spain is such an old country, and which permits mines opened in the days of the Phoenicians to still operate. Such deposits in America would be exhausted in a comparatively few years. The Phoenicians are supposed to have reached Spain about 1100 B.C. and to have worked some of the properties in the Rio Tinto district. The Carthagenians invaded the country about 236 B.C., and they were driven out about 205 B.C. by the Romans. The Romans ruled until 483 A.D., when they were overthrown by the Visigoths. Then, about 711 A.D., the Moors from Africa became prominent and they were finally expelled by the Spaniards in 1492. Spanish power reached its zenith under Phillip II, during the latter half of the 16th century, and since the close of that century the country has lost its prominent place among the nations. There are some evidences of revival in the development of good roads, the construction of a satisfactory network of railways, and the building of magnificent thoroughfares through the capital city, Madrid.

Jan 1, 1927

By Robert A. Brown

"The O'Brien mine is in the west-central part of Cadillac township along the Cadillac 'break', which extends for 7,500 feet from west to east across the property.The ground was staked in 1924 by A. Dumont and W. Hermeston, prospecting for M. J. O'Brien, Limited. The first vein discovered is that now known as No. 1. The No. 4 vein was later exposed on the surface; the other veins known to be present were revealed by underground work and diamond drilling carried out both from the surface and underground.The mine is developed from three vertical shafts: No .. 2 extending from the surface to 2,000 feet; No. 3 from the surface to 1,500 feet; and No. 4 from 2,000 to 3,000 feet. There is on the property a mill of about 200 tons a day capacity, the usual shops, and a townsite housing about forty-five families. Gold production to the end of September, 1944, amounted to 295,824 fine oz. from ore having an average grade of 0.505 oz. a ton. In addition, the mill recovered 3,237 tons of arsenic trioxide having a purity of 83 per cent As2O3.GENERAL GEOLOGYThe four main groups of rocks of the Cadillac area- the Cadillac, Blake River, Kewagama or Pontiac, and Malartic- are found within the boundaries of the property. However, as these rocks have been fully described in · various government reports (1,2,3,4,5,6) and all the known orebodies occur within one group- the Blake River-a detailed description of the geology will be dispensed with here. The known ore deposits lie south of the Cadillac 'break' in a group of rocks that includes 'greenstones', greywackes, conglomerate, porphyries, and a rock of gabbroic composition that may be intrusive. Both flows and tuffs can be recognized in the 'greenstones'. The two bands of porphyry that trend easterly across most of the property have been considered by some observers to be dyke rocks and by others to be flows. Certain evidence points to their being dykes that were intruded as sills considerably prior to the emplacement of the gold-bearing veins, but the possibility of flow origin cannot be fully rejected. North of the talc-chlorite-carbonate schist zone forming the 'break' the rocks are conglomerate and greywacke with iron formation, in which there are no known veins of ore grade. Within the schist zone are minor acid and basic intrusives. The general trend of both bedding and schistosity is a few degrees south of east. The dip is generally vertica1 or steep to the south."

Jan 1, 1954

By Jeanne B. Percival, Paul Ramaekers, Charles W. Jefferson, Pat A. Hunt, Eric G. Potter, Katherine E. Venance, William Davis, Sean A. Bosman

"A 10-cm thick clay-rich layer near the top of the Manitou Falls Formation of the Athabasca Group is unusual in its breccia texture, alteration, and detrital mineral composition relative to the adjacent overlying and underlying sedimentary beds. This layer is composed of angular quartz grains set in an illite >> kaolinite + dickite matrix. Deformed clay-rich fragments within the layer have very similar mineral assemblages. The presence of euhedral accessory minerals including Ti-oxides and aluminophosphatesulphate minerals points to a diagenetic/hydrothermal origin. The presence of individual grains of Kfeldspar and amphibole is unusual relative to the typical Athabasca quartz arenite; originally, these minerals were probably included in detrital quartz and subsequently liberated during fracturing. The textures and alteration characteristics suggest that this layer is a hydraulically-fractured unit, which has experienced hydrothermal fluid alteration - a possible pathway distally related to uranium mineralization Une couche argileuse de 10 cm d’epaisseur pres du sommet de la Formation de Manitou Falls du Groupe d'Athabasca est remarquable par sa texture brechique, son alteration et la composition de ses mineraux detritiques qui different de ceux des couches sedimentaires sus- et sous-jacente. Cette couche est composee de grains de quartz angulaires dans une matrice composee d’illite >> kaolinite + dickite. Des fragments deformes riches en argile dans cette couche presentent des assemblages mineraux tres similaires. La presence de mineraux accessoires idiomorphes dont des oxydes de titane et des aluminophosphates-sulphates suggere que ces derniers ont une origine diagenetique / hydrothermale. La presence de grains de feldspath-K et d'amphibole est inhabituelle comparativement aux arenites quartziques typiques de l’Athabasca; initialement, ces mineraux constituaient probablement des inclusions dans le quartz detritique qui ont ete subsequemment liberees pendant la fracturation. Les textures et les caracteristiques de l'alteration suggerent que cette unite a subi une fracturation hydraulique et a ete alteree par un fluide hydrothermal - possiblement en lien avec les effets distaux de mise en place de la mineralisation en l'uranium."

Jan 1, 2013

By W R. Honeywell

Two series of laboratory flotation tests were carried out to study the treatment of Faraday ore by two-stage flotation. First the acid-consumers and then the uranium minerals were floated. On ore ground in the Faraday mill grinding circuit, and using Faraday mill water in the flotation step, a recovery in the flotation concentrate of from 91 to 93 percent of the uranium was obtained in 45 to 50 per cent of the weight at a grade of 0.24 per cent U30s. The saving of acid in leaching the uranium-bearing flotation concentrate, as compared to leaching the whole ore, ranged from 30 to 46 per cent. The average over-all extraction resulting from flotation and leaching of the flotation concentrate was 88.1 per cent. The best collector for the acid-consumers was sodium oleate. Acintol F A-1 emulsion was the best collector for the uranium minerals, and, in the uranium flotation step, an acid pH in the slurry was found to be necessary. The reagent costs were estimated to be 22 to 26 cents per ton of ore.

Jan 1, 1963

By P. D. R. Maltby

This paper describes the background and markets for calcium carbonate and silica sand in Canada, as well as the results of recent test work carried out at the Ontario Research Foundation. Tests on sericite, tremolite, vermiculite, barite and graphite are also mentioned.

Jan 1, 1979

By L. Rosato

In the past decade, as a result of increasing iron loads, Canadian Electrolytic Zinc (CEZinc) has become a pioneer in understanding the critical factors that affect the roasting of concentrates with high pyrite contents as well as those factors governing the effects of high iron loads on the leaching circuit. De-bottlenecking efforts in the roaster and acid plant section of CEZinc have given rise to a better appreciation of the impact of iron on roaster productivity. High standards for impure solution quality, zinc recoveries and residue disposal have all led to an increased comprehension of the limits of the leaching circuit and the optimization potentials with respect to iron and ferrites. In this paper, the impact of iron on the roasting and leaching circuits of CEZinc will be reviewed and special emphasis will be given to some of the more recent process optimization and improvement activities.

Jan 1, 2006