Search Documents

By L. E. Djingheuzian

"ForewordTHE FOLLOWING excerpt is taken from Fine Grinding Investigations at Lake Shore Mines (C.I.M., Trans., Vol. XLIII, 1940, p. 307):""MacCalman, who has carried out exhaustive testing on the accuracy of screen analysis, makes the following statement in his report, The Accuracy of Sieving Tests, Industrial Chemistry (London, England), Vol. XIV, p. 231:"" 'It will be shown that, as no specific relationship between the sieving value and the various dimensional features of the sieve is evident, though there is an apparent tendency for the sieving value to follow the average aperture size, it is apparently impossible to define the sieving value of a screen from dimensions alone, and the calibration of sieves for important tests on a specific material, whereby the sieving values of these sieves are related to that of an arbitrarily chosen master sieve by correction values, will be recommended."" 'It will be emphasized that these correction values are probably not applicable to other materials, or the same material of different size composition. Sieve users, for important tests or in cases of dispute, will be recommended to calibrate their sieves against a mutually acceptable standard with specified conditions of test, and to recalibrate at intervals' ""."

Jan 1, 1953

By W. B. Timm

Introduction In preparing this paper on Recent Developments in Gold Milling Practice, the idea occurred to me that possibly the best way to deal with the subject would be to take you in thought on a visit to the principal gold mining camps of the Dominion, starting at the east and finishing up in the west, and noting, as we go, the outstanding improvements that have been made in the last few years in the practice of gold milling. Before beginning this tour, I desire to emphasize the debt this country, and particularly our mining industry, owes to that body of trained and experienced men, little heard of, but who, working quietly on their problems, are responsible for these improvements. The metallurgists, to whom I refer, have solved many difficult problems for the mining industry, in connection with the treatment of our complex ores; for instance, the silver-cobalt ores of the Cobalt district, the gold ores of the Porcupine district, the gold-telluride ores of the Kirkland Lake? district, the copper-gold ores of Noranda, the arsenical-gold ores of the Beattie mine, the copper-zinc ores of Flin Flon, and the lead-zinc ores of Kimberley. In doing so, they have maintained the high technical standards of the profession, and the practices thus evolved are noteworthy for their high degree of efficiency. When the price of gold increased from $20.67 to $35.00 an ounce, what had formerly been thought to be a low tailing became almost an ore, so that the metallurgists are now busily engaged upon the problem of putting this railing back in its proper place of being a tailing once more, or from its value, at the present price, of anywhere from 50 cents to a dollar or so per ton, to a few cents per ton. Owing to the changing prices of the metals in the world's markets, still greater improvements in metallurgical practices are imperative. An important contributory factor towards improvement in ore dressing is the aid furnished by the microscope in the examination of ores and mill products. By making possible the determination of the mineral constituents of the ore, their association, and grain size, it gives the investigator a knowledge of his problem, before he does any actual test work. In the Mines Branch laboratories at Ottawa, its use has enabled us to predict how an ore should respond to various methods of treatment.

Jan 1, 1935

By Erica J. Wanless, Ghislain Bournival, Seher Ata, Jose Hamilton Tavares

In froth flotation valuable particles are captured by bubbles and transferred to a froth layer where bubbles are in close proximity. Bubble coalescence frequently occurs in flotation, especially in the froth layer. The coalescence of two bubbles causes a release of energy, which may expel particles from the bubble surface. A series of experiments were carried out to determine the effect of bubble interfacial properties on the detachment of particles upon the coalescence of capillary-held bubbles of 2 mm in size. The interfacial properties of the bubbles were changed by the addition of low molecular weight alcohols, namely 1-pentanol or methyl isobutyl carbinol (MIBC). Using esterified glass particles (? = 43 °) with a 10 % and 90 % cumulative passing diameter of 47.2 and 92.5 µm, respectively, as model particles, it was found a certain concentration of frother, different for each additive, is needed in order to observe a reduction in the detachment of particles. In the presence of frother, the detachment was evaluated at approximately 65 % which was a considerable reduction in the detachment compared with the value of approximately 85 % found in the absence of frother. Frother molecules changed the properties of the airwater interface. Upon the coalescence of two bubbles, the release of energy caused the merged bubble to oscillate; effectively resulting in the detachment of particles. The addition of frothing agents augmented the elasticity of the bubbles, which appeared to be related to the detachment of particles. Whereas frothing agents are generally used to prevent bubble coalescence and stabilise the froth phase, only transient stability is imparted. The results suggested that an additional role of frothers in flotation is to decrease the detachment of particles from bubble surfaces. The type and concentration of frother can be strategically selected to improve metallurgical recovery as an economic incentive.

Jan 1, 2016

By M. K. Gangal, A. E. Hall, S. B. V. Stewart

"An investigation into the problem of atmospheric fog in Canadian mines is described. Fog occurs in several mines and the reduced visibility can result in the closure of workings for safety reasons. Information on the mechanisms of fog formation are discussed and the methods for improving conditions are reviewed with their relative costs.INTRODUCTIONAtmospheric fog occurs in several Canadian mines during spring and summer. The fog which reduces visibility, contributes to loss of production and increased accident risk . Closure of ramps in mechanized mines causes mining to be stopped or rescheduled, and stoping and grade control may be affected . Increased corrosion of equipment may result from acidic fog .Fog is commonly caused by saturated air being compressed and heated by an inlet fan and then being circulated in an ascensional system with heat transfer to the walls of wet airways. This causes supersaturation and water droplets condense to create fog, with liquid water contents of 0.5 g/kg to 3 g/kg of air. These concentrations reduce visibility to less than 10m and prevent mining. Less severe fog is usually tolerated as a nuisance, about which little can be done."

Jan 1, 1989

The Boleo project is located in Mexico close to the town of Santa Rosalia on the Baja Peninsula. The Boleo deposit contains copper, cobalt, zinc and manganese values as oxides with minor sulfides. The Boleo deposit is metallurgically challenging due to: 1) the requirement to recover four separate metals; 2) the presence of high levels of clay in the deposit resulting in difficult solid-liquid separations, and; 3) the need to use seawater for the bulk of the processing. Baja Mining, Bateman Engineering and SGS Lakefield Research have collaborated to develop and test a process flowsheet to recover copper, cobalt, zinc and manganese products at Boleo. The key steps in the flowsheet are: ? Feed preparation (scrubbing and ball milling of oversize) in copper raffinate ? Ore leaching using oxidative and reductive leaching ? CCD washing using high rate thickening technology ? Copper SXlEW ? Treatment of a bleed solution for cobalt, zinc and manganese recovery The process for cobalt, zinc and manganese recovery involves iron and aluminum removal followed by cobalt/zinc bulk extraction using CSIRO's DSX solvent extraction system and selective zinc and cobalt stripping. The zinc strip solution is evaporated to produce zinc sulfate monohydrate crystals to market and cobalt is recovered via a further SXlEW process as high purity metal. Manganese is precipitated as manganese carbonate from the DSX raffinate solution. This paper will review the Boleo process flowsheet and provide detailed results from the 2006 pilot plant operation conducted at SGS Lakefield in Canada.

Jan 1, 2007

By L. Voisin, G. Damm

"In order to develop a new pyrometallurgical process for eliminating detrimental arsenic and antimony from the impurity-rich matte produced from copper concentrate, and for treating the occasionally generated speiss in nonferrous smelting processes, the phase relations in the Fe-Cu-S-As-Sb system saturated with carbon at 1473 K were investigated. The distribution of elements between the condensed phases at the miscibility gap, where three equilibrated phases of iron-rich alloy, copper-rich alloy, and matte coexist, were also studied. The investigation was carried out by performing a series of laboratory scale experiments in an electrical furnace at 1473 K, followed by a quenching method on the final stage. The samples obtained from the experiments were analyzed by using Inductively Couple Plasma (ICP), Atomic Absorption Spectroscopy (AAS) and Carbon Infrared Spectrometry (CIS) techniques.The results were compared with previous investigations for the Fe-Cu-S-As-C and Fe-Cu-S-Sb-C systems and discussed on the basis of the molar fraction distribution for both arsenic and antimony in the matte phase at five different matte grades. It is expected that by using this phase separation technique it might be feasible both, the cleaning of a complex copper matte and the elimination of arsenic and iron together with an acceptable amount of antimony into the iron-rich alloy phase, which can be discarded as a harmless and smaller deposit."

Jan 1, 2014

By J. A. Beesley

This paper reviews contemporary international law concerning the seabed, current developments in the United Nations on the seabed, and the main outstanding problems. It emphasizes the importance that the Canadian government attaches to this area.

Jan 1, 1969

By A. R. Kinkel JR.

"The Buffalo Ankerite mine is in the southern part of the Porcupine gold district of northern Ontario. The mine has a history of exploration and development reaching back to 1911, and has been operated continuously since 1932. From 1932 to 1942 a total of 510,874 oz. gold was produced from the mine. In 1941 the production was 71,654 oz. from 448,621 tons of ore.With few exceptions, the ore-bearing veins did not crop out. They were discovered during the prospecting of the prominent outcrops of barren or low-grade quartz-carbonate breccia near the veins.GEOLOGICAL SETTINGThe Porcupine gold district lies in an area of folded and sheared Precambrian lavas, sediments, and intrusives. The Buffalo Ankerite mine is in the southern part of a large fold. The structure appears to be a continuation of the Vipond cross anticline and accompanying syncline described in earlier papers (1, 2). The orebodies lie along both flanks of the synclinal part of the fold, and are known as the north and south vein systems, respectively. No mineable veins have been found on the axis of the syncline (Fig. 1).The rocks found in the mine area are pillow lava, dacite, conglomerate, quartz porphyry, tuff, and fragmental lava. The tuff and fragmental lava are now largely altered to chlorite schist. Productive veins have been found only in pillow lava, dacite, and conglomerate, but a minor amount of gold occurs in some of the quartz porphyry. The Porcupine Creek fault, a zone of intense shearing over 1,000 feet in width, lies immediately south of the mine. A spur fault branches to the northwest from the Porcupine Creek fault, separating the north from the south vein systems ( Fig. 1) ."

Jan 1, 1954

By W. G. Jewitt

Introduction The use of the aeroplane in prospecting is already familiar to everyone connected with the mining industry. Apart from transportation companies, three organizations, the N. A. M. E., the Dominion Explorers, and the Exploration Department of the Consolidated Mining and Smelting Company, have made the aeroplane an everyday feature in every mining district in Canada. Its use has been demonstrated successfully in the mountains of British Columbia, but perhaps its greatest field lies in the Canadian Shield, where the numerous lakes and rivers afford an almost continuous series of landing places for aeroplanes, on floats in the summer and on skis in the winter. To the man who has travelled by canoe, toiling over fly-infested portages or held for days at a time, wind-bound, on the big lakes, the ease, speed, and cheapness of aeroplane travel have marked the beginning of a new era, in which ground previously covered with difficulty in a month or more is travelled with ease in a few hours. Development of an air service in the Consolidated Mining and Smelting Company has proceeded on different lines from those of other organizations, and this paper is concerned with that development.

Jan 1, 1931

By W. L. Goodwin

Twenty-five years ago mining engineering in Canada was not a profession. To-day the members of the mining fraternity can fairly claim for 10themselves the professional status. If their pretension is not fully warranted by fact it is not for lack of any technical attainment or service to the public but by reason merely of their neglect to cultivate the cohesion and consciousness that are the outward and visible signs of a professional body. This paper is an attempt, first to sketch briefly the course of the events during the past thirty-five years that have resulted in organizing the mining industry of this country in its present form; then to notice the principal features of the professional organization of this day; and finally to point out that an important part of the work of the mining engineer remains in the state of chaos that characterized the whole of it three or four decades ago, and to suggest a remedy. Thirty years ago there came a great wave of interest in mining in Canada, based principally upon the discovery of gold-quartz and gold-copper throughout wide areas in Nova Scotia, Ontario and British Columbia.

Jan 1, 1926

By Morris Wong

"An antimony-bearing gold ore was studied in a cyanide slurry containing 7 -20 ppm dissolved oxygen. 1 g/L NaCN at pH 9.5 and 48 hours retention time is required to extract 94 % of the gold from the 90 % minus 200 mesh ore by conventional cyanidation at a 7 ppm O2. As oxygen concentration was increased to 20 ppm, the conditions required to extract the same amount of gold were: 0.25 g/L NaCN, 16 hours retention time and 80% minus 200 mesh. Compared to conventional cyanidation, oxygen-enriched leaching was shown to reduce retention time by three times and cyanide consumption by four times. The kinetics of gold dissolution related to the dissolved oxygen concentration in slurry was expressed by following equation:XAu = 100 * (Kt + I0) / (1 + Kt + I0)where XAu is the percentage gold extraction; t is the retention time; K and Io are the slope and the intercept of the plot of XAu I (100 -XAu) vs. t respectively. The values of Kand Io depend upon the concentrations of cyanide and oxygen, the fineness of grind and the origin of ore sample etc.. A preliminary cost analysis was also performed to justify the use of oxygenating slurries.IntroductionGeneral:It was proposed almost 149 years ago (Elsner 1846) that oxygen is required for the dissolution of gold in cyanide solution. However, little attention were paid to oxygen application in the gold milling industry during the following one hundred years. Due to the constraints of gold price, reagent costs, refractory ores, and environmental issues in the past decade, the oxygen enhancement in the cyanidation process was introduced to the gold milling industry for increasing operation efficiency, reducing production costs, and meeting the requirement of environmental standard.The advantages of oxygen-enriched cyanidation have been reviewed by several investigators (Hague 1992, Jara et al 1992, Henderson 1989, Loroesch et al 1988, Elmore 1987, Cathro 1963). Common to all conclusions are the following advantages."

Jan 1, 1995

By C. W. Reno

"THE LORNEX MINING PROJECT is one of several large-tonnage, low-grade operations recently placed in operation in British Columbia. It is located in the Highland Valley in the south central portion of the province. This area is described as a divide valley at an elevation range of 4,000 to 6,000 feet and is situated on the divide between two drainage systems. The major drainage to the west flows into the Thompson River and to the east and south the drainage enters the Nicola River system. This open-ended valley lies between low, rounded mountains in fairly heavily-wooded country. Prior to the commencement of copper mining activities, the first by Bethlehem Copper Corporation Ltd. over ten years ago, the valley was only sparsely settled. A few small ranches were in existence on the several Indian Reserves located along the valley bottomland. There has also been a small amount of logging activity in the valley, although much of the area is covered by dense lodgepole pine which has little or no value to the loggers. As the mining interest mounted with further discoveries of the disseminated copper ore typical of the district, much of the valley was covered with mineral claims and exploration drilling was carried on by several companies at various times. At the time Lornex was preparing to commence major construction work in early 1970, there was very little activity of any kind in the Highland Valley outside of the Bethlehem operation and a small amount of ranching."

Jan 1, 1973

By G. J. Hamilton

"THE Royalite-Canada Southern Coleville No. 1 gas strike of August 15th, 1951, and the closely following low gravity black-oil strike of August 23rd, were the first of a series of recent oil and gas discoveries in western Saskatchewan. They are in what is now known as the Coleville field, 25 miles north and west of Kindersley and 30 miles east of the Alberta-Saskatchewan border (Figure 1).Gas flows have been recorded in the Viking sand at daily rates of between 5 and 10 million cubic feet, and black oil of 15° A.P.I. gravity is produced from Mississippian sediments of Banff age at a daily rate .of 50 to 100 barrels on pump.Development drilling was carried on during the winter months, with very little attempt at step-out exploratory ventures. This year, however, a step-out programme to the northeast (Figure 2) is •being carried on in order to determine the position of a possible truncation of Mississippian sediments in that direction. Section 30 of the Coleville area has been fully developed on a 20-acre wellsite basis, and structural information is restricted to local rather than regional interpretation. No attempt will be made in this paper to interpret the Coleville area with respect to the regional geology in any but a general manner."

Jan 1, 1952

By Larry T. Yano, Gerald T. Handford

"Tailings Engineering has the responsibility for planning and coordinating tailings disposal and for ensuring the stability of the tailings dyke. The inclusion of both the planning and geotechnical functions in one team has resulted in greater efficiency in the design and planning process. Major challenges in tailings disposal facing Syncrude are in the areas of: (1) sludge disposal; (2) instrumentation and monitoring; and (3) liquefaction. Meeting these challenges will have a significant effect on the cost effectiveness and reliability of the mining operation.IntroductionThe size of the tailings disposal operation has led to the establishment of a large engineering team devoted solely to the disposal of tailings. This paper discusses: the tailings disposal operation, the role of tailings engineering, the organization, inter faces, and the present and future challenges with respect to tailings disposal."

Jan 1, 1990

"No questions.F Energy Consumption in Industrial Minerals : E.Joe No questions.g Automatic Dewaterinq at Mattagami : M. CaronE. Marcotte Is the control valve on the thickener underflow reducedFalconbridge as the pulp density reduces?Reply As the slurry density reduces the valve will constrict to reduce the flow and the density will re-establish itself.E. Marcotte Is there a stopper on the valve to prevent its closing too far?Reply We never shut it off completely because of the danger of sanding. It is just brought down to a normal level. It works very well within a given range and the operator is on hand to prevent any sanding out in the line."

Jan 1, 1984

By Shae K. Kim

The aim of this study is to manufacture magnesium alloys with alkaline earth metal oxides (BeO, CaO, MgO or SrO) additions with the objectives of (1) ensuring safety during processing and applications by raising the ignition temperature and reducing oxidation, (2) protecting the environment by reducing or eliminating use of protective gases, (3) maintaining or improving elevated temperature properties with lower amount of Ca or Sr or rare earth metals when compared with conventionally developed high-temperature magnesium alloys, (4) developing cleaner strip casting and continuous casting processes without hot tearing and (5) obtaining all of these objectives without sacrificing mechanical properties or increasing the cost of magnesium alloys.

Jan 1, 2006

By T. Bhambhani, O. Yavuzkan, D. R. Nagaraj

"Cu ore bodies commonly contain oxide Cu at the surface, with sulfide Cu content increasing with depth. The recovery of oxide Cu minerals by flotation is a longstanding challenge in the minerals industry, especially for high acid-consuming ores which would not be economical for direct acid leaching. Current practice of oxide Cu recovery involves sulfidization (often using controlled potential sulfidization or CPS) using NaSH (or Na2S) followed by flotation using traditional sulfide collectors. CPS has shown to improve recovery of oxide Cu but has the following limitations: a) HSE issues with NaSH, b) high consumption of NaSH, and c) inability to recover certain oxide Cu minerals because they are refractory to sulfidization. The oxide Cu flotation is further complicated by the presence of certain non-sulfide gangue minerals which adversely impact both recovery and selectivity.Over the past eight decades, numerous collectors have been proposed and evaluated for the direct flotation (i.e. without sulfidization) of oxide Cu minerals, the most researched of which is alkyl hydroxamate. While there are numerous publications dealing with the fundamentals of interaction of alkyl hydroxamates with single minerals, there are few publications which discuss the practical aspects of alkyl hydroxamate use in ore flotation, particularly their use with sulfidizing agents. Case studies in this paper include methods to identify optimum combinations of sulfidizing agents and oxide collectors to maximize recovery for various types of ores. It was observed that some ores do not require any sulfidization, while others require at least partial sulfidization to improve efficacy of AHX. Depending upon the ore type and mineralogy, recovery improvement in the range of 5 to 15% units, over and above that achieved with CPS, has been observed with the use of AHX. For ores requiring high dosages of NaSH, it was shown that AHX can be used to reduce the NaSH consumption significantly. The challenges associated with the presence of non-sulfide gangue minerals in oxide copper ores are included, and the use of modifiers to alleviate the associated problems and enhance the performance of AHX is discussed."

Jan 1, 2016

By P. Au, R. Kearsey, D. Y. Seo, Patnaik. P. C.

Three nickel based superalloys (7.5%Cr+5%Co+2%Mo+1%Ti+5%Al and Ni balance (wt%)) containing different amounts of W and Re were produced in the single crystal (SX) condition utilizing the Bridgman casting process. First, the effect of different levels of Re, and W on chemical microsegregation were investigated by EPMA quantitative analysis, and eutectic phase fraction analysis. Second, in order to investigate the effect of these refractory elements addition on oxidation behaviour, isothermal oxidation testing of the SX nickel based superalloys was conducted at 1000°C for 277 hours under 3 ppm moisture content of air in a thermogravimetric analyzer (TGA). All three SX nickel based superalloys revealed an excellent SX solidification structure with a common primary dendrite arm spacing of -250 µm and a large fraction of ?/?' eutectic located between the secondary dendrite arms. From the average EPMA compositional results, with the exception of Ni, elements such as Cr, Co, Re, Mo, and W all tended to segregate towards the dendrite core during solidification, while Al, Ti, and Ta were present in greater quantity in the last liquid phase to solidify, which resulted in large eutectic ?/? ' phases to form within the interdendritic regions. As the nominal level of Re increased, microsegreagation of Re, W, Cr and Mo increased, indicating that Re had a much greater influence on partitioning behavior compared to W. Figure la shows the specific mass gain as a function of exposure time for each alloy. An alloy with 2wt% of W and Re (Alloy B) exhibited less weight gain compared to two other alloys with either higher content of W or Re (Alloy A and C). Microstructural and compositional analyses of oxidized samples were conducted using SEM and EDS. Figure lb shows the typical surface morphologies of the oxidized Alloys A and B. It is evident that more oxide nodules (indicated by arrows in the figure) were presented in Alloy A. It is speculated that the amount of these nodules was responsible for more mass gain in Alloy A compared to the two other alloys. From the examination of the longitudinal section of the oxidized samples as shown in Figure 2, for Alloy A, nodules actually penetrated deep into the material. For Alloy B, however, a relatively uniform and continuous oxide layer was developed and deeply attacked areas were not observed. It was also found that preferential oxidized regions were located at the area between the ?/?' eutectic phase and the dendrite arms where the concentration of refractory elements was relatively high. Therefore, it is plausible that the oxidation kinetics of these alloys is related to the extent of microsegregation.

Jan 1, 2004

By Cesar H. Oboni

The development of specific risk-based methodologies to guide and prioritize clearing decisions in countries contaminated by Unexploded Ordnance and Land Mines (generically defined as Explosive Remnants of War: ERW) either at country-wide scale or road-network-scale was used in an unexpected way when a large mining company asked Riskope (www.riskope.com) to develop a multi-modal transportation network risk assessment plan, which included ocean going vessels, ports, wharves, railroad, trucking and other modes of transportation. What had been a first-in-the-world attempt in the humanitarian landmine clearing industry turned out to be extremely useful and equally innovative in the extractive corporate world. Instead of a country contaminated by man-made hazards such as Explosive Remnants of War (ERW) we were now dealing with a very complex multi-modal transportation system afflicted by all sorts of potential hazards from quakes to climate change, sabotage to labour strikes, and vulnerable infrastructures to potential energy crises. Interestingly enough the method developed to deal with ERW risk based clearing was also capable of solving the transportation risk evaluation problem, after necessary customization. This paper shows how ?out of the box? thinking and industry cross dissemination can bring significant evolution and a competitive edge even to unexpected areas of the world-wide mining industry. The results of the logistic system risk assessment shed new light on the management of the system, changed the way insurance coverage was purchased, and led to significant potential cost reductions in a period of global recession.

May 1, 2010

By S. Sopher, C. Barsotti

"Inco Gold Company was created in 1987 as an unincorporated business unit of Inco Limited. In 1988, Inco Gold Management Inc. was incorporated to supply management, exploration and engineering services to this unit. The first new project, at Casa Berardi, Quebec, was brought to production in September 1988, less than two years after completion of exploration. For 1989, Inco Gold's exploration and capital expenditures have been budgeted at approximately $94 million, a record level. Inco Gold holds interests in more than 80 precious metals ventures and prospects in Canada, the United States, Brazil, Indonesia, Papua New Guinea and France. The most advanced projects, in addition to Casa Berardi, are at Mineral Hill, Jardine, Montana, where initial production is anticipated in the third quarter of1989, and Crixas in central Brazil, where production is scheduled to begin during the fourth quarter of the same year.BackgroundTraditionally, Inco Limited's mineral exploration has concentrated on nickel and other base metals but since the early 1980s Inco's exploration activity has focussed strongly on precious metals, principally gold. As a result, three deposits have been discovered and developed . In order to accelerate the establishment of a strong gold mining enterprise with its own specific growth and profit objectives, Inco Gold Company was created in 1987 as an unincorporated business unit. At the end of 1988 Inco Gold's share of drill-indicated gold reserves was approximately 14 million short tons containing 3.4 million ounces of gold.At Casa Berardi in northwestern Quebec, one mine is in production and another is planned to open in 1990. Properties at Crixas in Brazil and at Jardine, Montana, U.S.A., were being readied for production in 1989. By 1991, Inco Gold's share of gold production is expected to be 125 000 ounces with a target of 400 000 ounces annually by the mid-1990s."

Jan 1, 1990