Search Documents

By J. G. MacGregor

At this, the opening meeting of the Western Quebec Branch of the Institute, it seems fitting that the first paper presented should embrace a survey of the known mineral deposits occurring in the area, and also a review of ?the exploration methods that have brought about their discovery. And since the study of geological structures must always be the guiding principle of an intelligent exploration campaign, it also seems to be the appropriate occasion to review the geological situation from the economic angle, in an attempt to arrive at a re-statement of the known facts governing the deposition of the mineral bodies . . It is not my intention to confine my remarks entirely to the geological problems involved, but rather to pass under review the exploratory methods that have been employed in the past and that are presently being used, and to offer a forecast of the type of exploration campaign that will be largely adopted in the future search for ore.

Jan 1, 1929

By Kretschmar. U. H.

Fieldwork in the Meguma of Nova Scotia and Archean equivalents shows that bedding-parallel quartz lode gold veins (LVs) commonly occur at the top of graded elastic sequences. We define a "gold cycle" (GC) by analogy with Bouma turbidites and show that most "shear zones" and "lamprophyres" correspond to the upper pelagic-pelitic (E) division. We describe GCs from Archean Chester Twp, ON; Elmhirst, ON; Bourlamaque, QC; "intrusions" and interpret them as crystal tuffs and tuff-breccias. Extensive early Archean pyroclastic volcanism is implied: the genesis of trondjhemite-tonalite-granodiorite (TTG) rocks must be re-examined. The geopetal nature and asymmetric alteration of LVs indicates genesis from sea-floor hydrothermal vents. Textures suggest that often quartz was deposited as a gel. Vent geometry (fracture, point source or diffuse seep), bottom topography and vent spacing is reflected in wade-thickness plots. GC facing directions survive metamorphism. The Bourlamaque batholith was a flat-lying sheet of quartz-feldspar-hornblende crystal tuff, and isoclinal folding has repeated one or more gold-bearing horizons. Syngenesis clarifies and simplifies LV formation with major implications for models. Exploration becomes more cost-effective. Basin analysis, whole rock geochemistry, ore lens geometry and vent spacing can be used.

Jan 1, 2011

By Matthew Blecha

The Tribag copper deposit is one of the rare examples of mineralized breccias in the Canadian Shield. The breccia is a pipe-like body, and consists of granitic, diabasic and volcanic fragments embedded in a vuggy, quartz-carbonate matrix. The mineralization is essentially chalcopyrite and pyrite, with minor molybdenite, sphalerite, galena and other sulphides. The main ore zone is saddle-like in shape, and is enveloped in a zone of chloritization, sericitization and clay-mineral alteration. It is suggested that the breccia is of the diatreme type. Introduction T HIS paper is based on eighteen months of field work, including surface and underground geological mapping and core logging, and on the survey of relevant literature. No significant amount of laboratory work has been done as yet. Location and Access The Tribag Batchawana property is located 40 miles north of Sault Ste. Marie, Ontario, about 10 miles east of Lake Superior. A 17-mile, all-weather road connects the property to the Trans-Canada highway to the south, and 4 miles of a 12-mile road remain to be completed to link it to the Algoma Central Railway to the northeast.

Jan 1, 1965

By R. Agius, A. Nacu

"Adoption of the International Cyanide Management Code, regulatory requirements and community concerns have increased the need to implement suitable cyanide destruction processes at gold operations to meet ever more stringent discharge limits. As standards set for the allowable concentrations of cyanide, cyanide compounds and other contaminants may vary from country to country, jurisdiction to jurisdiction, and even from site to site, there is no “one size fits all” technological solution. Currently the most common cyanide destruction processes used in industry are sulfur dioxide/oxygen, hydrogen peroxide and Caro’s acid. Regardless of the process used, cyanide destruction plants must be reliable and achieve permit guidelines at all times. The selection of the most appropriate cyanide destruction process for an operation depends on several factors, including permit discharge requirements, tailings chemistry, location, site-specific climatic conditions and size of the operation. Only after considering all these factors together can the most effective approach be selected to achieve the permit guidelines economically and technically feasible. Finally performing the correct test work program is the most important step to ensure that the correct process design criteria can be determined to accurately calculate capital and operating costs.IntroductionThe adoption of the International Cyanide Management Code in 2005, stricter regulatory requirements and community concerns prompted by environmental incidents involving cyanide have increased the need to implement cyanide destruction processes at gold and silver operations.Process solutions associated with the extraction of gold and silver contain several forms of cyanide. The most toxic form of cyanide is free cyanide, which can be present as a dissociated cyanide anion (CN-) or gaseous or aqueous HCN. Weak or moderately stable cyanide complexes such as those of zinc, copper and nickel are classified as weak acid dissociable (CNWAD). Although less toxic than free cyanide, weak acid dissociable cyanide complexes are considered “ecologically sensitive” forms of cyanide and are regulated in most jurisdictions. In practice, reported WAD cyanide values are comprised of both free cyanide and weak acid dissociable cyanide complexes. Cyanide complexes with gold, mercury, cobalt and iron are referred to as strong acid dissociable complexes (CNSAD) and are much more stable even under mildly acidic conditions. Another term commonly used in cyanide chemistry is total cyanide, which represents all cyanide compounds present in solution, with the exception of cobalt complexes. Total cyanide levels in solutions are in most cases higher than WAD cyanide values and the difference between the two usually indicates the presence of iron-cyanide compounds. Typically, in Canada CNTOTAL levels cannot exceed 1 mg/L in solutions."

Jan 1, 2017

By Heribert F. Broicher

By the very nature of mineral deposits the quality of the raw material generally fluctuates and should be known for optimum processing. Early classification, for example, of limestone into road-metal grade or lime grade or of run-of-mine ores into high grade, low grade and waste as well as information for blending or for dosage of reagents are prerequisite for economic processing. Non-contact, real-time and on-line rock identification or assessment of quality parameters can be realised by introducing the analysis of laser-induced fluorescence (LIF) into the mining industry. LIF analysis is an optical method evaluating the basically known photoluminescence properties of matter, however, extending the application into hitherto unimagined fields by use of high-energy pulsed lasers and time-resolved analysis of fluorescence in the ultra-violet, the visible and near-infrared domains of light. LIF analysers and test work in a limestone quarry and a cement plant in Germany as well as in an iron ore mine in Sweden are described. First results of test work are available and proof this technology to be promissing.

May 1, 2002

By J. W. Hohn

The precipitation of Fe(III) to form ferrihydrite in the presence of arsenic is the United States EPA's Best Demonstrated Available Technology for treating arsenic-containing hydrometallurgical solutions and waste streams. This technology has been widely adopted throughout the world and developments have been well reviewed. The adsorption and long-term stability of ferrihydrite can be improved by co-precipitating Fe(III) and Al(III) together to form an aluminum-modified ferrihydrite. Arsenate adsorption into ferrihydrite and modified ferrihydrite as a function of pH, Fe/As or (Al+Fe)/As mole ratio, and the initial As(V) concentration is presented and compared. The results of long-term aging of both adsorbents at 70°C for over a year are also summarized.

Jan 1, 2006

By R. Binning

"Economic high density mineral reclamation and subsequent transportation of solids through a pipeline presents many formidable engineering problems.Mineral reclamation system design by theoretical formulas is almost impossible because solids composition, ie. concentration, velocity, moisture content, solid size, etc. can only be controlled within a broad pumping range.Traditionally this has restricted pumping to relatively dilute slurries whereas it is usually preferred, because of economic considerations to reclaim as high a concentration as possible.At Toyo/De-Velde Corp. we recognized these pumping limitations and began to develop and manufacture a range of standard and auxiliary equipment that would exceed these technical restrictions.MATERIAL RECLAMATION & PIPELINE INJECTIONTo minimize fluid usage and increase material reclamation efficiency we designed a submersible dredge mixing pump that uses most of its energy to pick up material from rest, mix it with fluid into a highly concentrated slurry then push it firmly into a pipeline.Where material is too compacted to be mined by the standard submersible mixer pump, auxiliary high torque self contained submersible excavators can be fitted around the periphery of the mixer pump. This is to facilitate excavation and break up of the compacted material into a slurry.High flexibility of this system can be achieved by combining the many equipment variations available into the most efficient format to fit individual site requirements.Whatever combination of equipment is selected, torque is nullified by counter rotating excavators against each other. This increases effective excavator/material bite torque but also allows mixer/excavator rig suspension by cable for deep water material recovery."

Jan 1, 1985

By J. A. Finch

For base metal sulphides, iron rejection starts in mineral processing. This review focuses on the changes in plant practice specifically to improve iron sulphide rejection by controlling contaminant ion effects and discusses selected innovations in mineral processing that can be expected to play a role in iron control. One change to control contaminant ions is size reduction (the use of stage grinding and inert stirred milling) and another is system chemistry (order of reagent addition and exploitation of the flexibility of sulphoxy species). Plant examples illustrate the successes, and indicate that there are several options available. The general innovations consider the new tools for measuring gas dispersion properties and quantifying froth characteristics from images. Examples of their application to improve concentrate quality illustrate the potential. Other innovations adapt geostatistics to model variations in ore flotation response to provide feed forward control and rigorously apply the statistical experimental methodology in plant test work. An example from one concentrator shows that significant improvements to reduce the iron content of concentrates can be achieved by applying these basic principles.

Jan 1, 2006

By M. A. Marois

This paper proposes an improved temporal stability condition for the implementation of an inverse heat transfer method for predicting the time-varying bank thickness of the phase change protective bank inside a high temperature furnace. The direct problem is handled with the enthalpy method. The inverse method rests on the Adjoint Problem and the Conjugate Gradient Method. It is shown that the temporal stability condition for the inverse phase change problem relies on the time delay of the temperature measurements. Results indicate that this time delay is proportional to the heat diffusion time including heat diffusion through the mushy zone.

Jan 1, 2011

By P. E. Davidson

The management of solid waste is known to be a large and increasing problem in high-population areas throughout the world. It is not necessary here to add further definition to the nature and magnitude of the problem. Instead, it is the purpose of this paper to describe a new process, called the Andco-Torrax System, which will be of use in converting municipal solid waste into useful energy forms and a granulated slag by-product. The paper includes a description of the first commercial plant for the process.

Jan 1, 1977

By Ben Bradshaw

Context ? Community engagement has become an increasingly significant and challenging part of mineral exploration and mine development; indeed, opposition from communities proximate to a proposed mine site has been known to derail technologically- and financially-sound projects. ? These cases suggest that mining firms need to better understand how to engage constructively with local communities in the pursuit of their claims. ? While a range of publications exist promoting various community engagement strategies, these recommendations, when viewed as a whole, are disjointed and largely untested in real development contexts. Aims of Presentation 1. Synthesize industry, NGO, government and academic publications focused on community engagement best practice in order to highlight those practices that are most commonly recommended. 2. Review the (Canadian) mining industry?s experience with some of these strategies based on existing case material in order to identify the extent to which commonly prescribed strategies are used and validated in practice.

May 1, 2010

In April, 1961, a large pillar was removed by blasthole mining methods at Inco's Murray mine. More than half a million pounds of explosives were used to break 2,120,000 tons of ore in a single underground blast. The 5, 10 2-inch boreholes, involving 435,815 feet of drilling, were loaded over a three-week period, using conventional explosives and short-period electric caps. From this blast, more than half a million tons of ore have been removed to date (April, 1962) through slusher trenches situated in the footwall of the ore body. T HE Ontario Division of The International Nickel Company of Canada, Limited, operates six underground mines and two open pits in the Sudbury district in the north-central part of the Province. This paper describes the removal of a large pillar at the Murray mine (Figure 1), where 2,120,000 tons of ore were broken in a single underground blast by the blasthole mining method. This is the largest underground blast achieved to date (April, 1962) at Inco mines.

Jan 1, 1963

By A. Zangooi, J. A. Finch

Flotation is a separation process based on the collection of particles on the surface of bubbles. Flotation machines disperse air into bubbles using a variety of techniques. The characteristics of the bubble population are strongly affected by the selection of frother type and concentration. As metallurgical results depend on the bubble distribution, the measurement of frother concentration is vital to understand and control performance. A previously developed colorimetric technique was refined to work with low solubility frothers and to increase daily analysis rate. Field-testing demonstrated that the method is robust, reliable and accurate. As well as relating frother concentration to gas dispersion measurements, the results can be used to answer operational questions including: how well a frother dissolves, how reliable and stable frother delivery is, how evenly frother is distributed down a bank, and whether frother distributes between the pulp and froth zones. Some of these points are illustrated from plant experiences. Advances in Mineral Processing Science and Technology Proceedings of the 48th Annual Conference of Metallurgists ofCIM Sudbury, Ontario, Canada Edited by

Jan 1, 2009

By Nabeel Khan

Annual oil production from the Canadian Oil Sands in Northern Alberta has been rising for several decades, and more ore and overburden are excavated each year from an increasing number of open pit mines. Overburden meeting certain specifications will be used to dam tailings and fill open pits, but the remaining material must be stored in overburden storage structures (OBSS). Well-designed overburden storage structures are more stable and cost less in the short- and long-term. The purpose of this paper is to explore OBSS designs that will be stable yet economical in the short- and long-term. The geological background of the site is briefly discussed, including the effect of each of the main geologic layers (recently deposited till and muskeg, Clearwater Formation clay shales, McMurray Formation oil sands, and the Devonian limestone) on the slope stability of the OBSS. Cost is considered in the analysis when balancing between minimizing costs (steeper slopes) and acceptable factors of safety (flatter slopes), all the while considering the financial consequences of failure. Potential failure planes are identified and probabilistic analysis is conducted on the critical failure surface. The variations in the factor of safety caused by varying pore water pressure, friction angle, and cohesion, are plotted and discussed.

Jun 1, 2012

By D. Auerswald, M. Kotze, V. Yahorava, T. Udayar

Uranium can be recovered from lower grade uranium ores (<800 mg/kg U3O8), leach residues, and waste dumps cost-effectively via resin-in-pulp (RIP). Using this technology, no solid/liquid separation or washing of the leach residues are required. Furthermore, the uranium recovery can be higher than with conventional methods. RIP technologies have, however, been perceived negatively due to concerns around potential resin fouling and losses. This paper highlights the advancements made in RIP and discusses a number of potential applications where the technology could deliver economic and consequential environmental benefits by reducing the uranium levels in the waste.

Jan 1, 2014

By R. Matusewicz, A. Kaye

Ausmelt Top Submerged Lancing (TSL) Technology has gained widespread commercial acceptance in non-ferrous applications, including the processing of lead and zinc primary concentrates and secondary (post-consumer) materials. TSL is highly flexible and efficient, and is one of the few technologies which can process primary and secondary feeds, and use varying fuels, to deliver high recoveries and excellent environmental performance. With the recent high value of both lead and zinc, and an escalating awareness of the sustainable use of resources, focus on the processing of secondary feed material sources has surged. Ausmelt Technology has proven to be well suited to the economic recovery of values, with twenty-two (22) Ausmelt furnaces processing lead and zinc bearing feed sources now in operation, under design or construction. This paper describes Ausmelt&apos;s progress in the fields of lead and zinc processing, and developments in new processing areas such as EAF dust processing and linking to innovative hydrometallurgical technology. Ausmelt has recently committed to the Whyalla Zinc project as the owner/operator of a facility for the treatment of zinc bearing secondary feeds. This project is due for start up in the first quarter of 2008.

Jan 1, 2008

By P. B. Queneau, Peter V. Avotins, Lauch F. Farris

"The Lang Bay germanium property is a carbonaceous sandstone deposit outcropping near the Pacific coast, 100 km north of Vancouver. The germanium-bearing seams are up to 5 m thick. Where one such seam outcrops, it averages 50 to 60 g Ge/tonne. Drill core analyses have shown considerably greater concentrations of germanium at depth. Additional drilling to establish continuity and grade of the germanium-b earing strata is scheduled for 1986. The germanium occurs in association with lignite, which makes up 1 to 2% of the seam. American Cyanamid Company engineers have developed a proprietary flotation reagent effective for concentrating the germanium rich vitrain portion of the Lang Bay lignite. Ongoing laboratory studies are developing procedures for further upgrading and refining of this germanium. This paper outlines progress made by Fargo Oil Corporation on Lang Bay geology, reserve estimation, mine planning, ore dressing, refining, and economic evaluation.IntroductionIn 1871, Mendeleyev specula ted on the properties of a ""missing"" element between silico n and tin on the periodic table. The discovery of germanium fifteen years later proved the Mendeleyev predictions to be remarkably accurate. Almo half a century later, the pioneering work of McCutcheon of Eagle-Picher led to production of germanium dioxide from Oklahoma zinc smelting residues. Demand for the element surged due to development of the Ge02 diode rectifier during World War II, followed by development of the transistor in 1947. The chief commercial sources for germanium during the following two decades were the Cu-Zn mines in the Congo and the Zn-Cu-Pb mines of Tsumeb in Southwest Africa. The germanium was chemically combined in complex Cu-Fe sulphides (germanite and renierite), from which the element was recovered either by leaching the selectively roasted sulphide, or by direct fuming of GeS(I). Although these deposits have reportedly been depleted (2), new deposits of renierite have been discovered in Zaire. Alternative sources of germanium are therefore being sought worldwide for use in infrared optics, semiconductors, fibre optics, and catalysts. One such source is germanium-rich coal (2)."

Jan 1, 1986

By A. Musschoot

"The paper will review general types and designs of vibratory feeders, describing briefly the design features and characteristics that apply to the application of specific types. Control considerations for selecting types will be dis• cussed, such as fixed or adjustable, manual or automatic, individual or multiple bank, and process requirements. Design parameters for hopper openings and installation geometry will be discussed, including consideration of material size distribution, segregation, moisture content and other characteristics, based on practical applications and experience as well as theory. Pan designs and the selection of pan materials will also be discussed with reference to wear, corrosion, impact and practical economic factors."

Jan 1, 1972

By W. G. Stevenson

With the author's background of extensive experience, this paper delineates the role of the prospector in modern-day exploration programs. The stages in the development of a prospect to a producing mineral district are outlined, and examples are given from the Ross River area of the Yukon Territory and the Peachland and Highland Valley areas of British Columbia.

Jan 1, 1970

By Jochen Petersen, Caroline Muzawazi

The technical feasibility of ammonia leaching of PGM bearing Platreef flotation concentrates was investigated as an alternative method for the recovery of base metals prior to precious metal recovery. The composition of the concentrates includes 2.02% Cu and 3.17% Ni, and the major base metal minerals are chalcopyrite and pentlandite. Optimal leaching conditions were initially established in shake flask experiments to be a solution containing 4 M NH4OH, 4 M (NH4)2CO3 and a pH range between 9 and 10. These were used as base case conditions in column and batch stirred tank reactor tests, where the effects of total ammonia concentration and operating temperature were explored further. At optimal conditions nearly 100% Cu and Ni extraction were obtained in the batch stirred tank reactor, and 95% Cu and 60% Ni extraction was obtained in columns. The activation energy for chalcopyrite and pentlandite was 36 kJ/mol and 16 kJ/mol, respectively, in both reactors, indicating different reaction pathways for the two minerals. Gas-liquid mass transfer appears to be the limiting reaction step in columns much more than in tanks, and the degree of ammonia loss to air is significant. This initial test work indicates the feasibility of using ammonia leaching for this and similar materials as an alternative route to conventional smelting and refining prior to PGM recovery, but a number of technical challenges still need to be overcome.

Jan 1, 2014