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By Claudia Gasparrini

"Factors affecting the extraction of gold are of a mineralogical nature. Knowledge of the mineralogy of the ore or metallurgical product to be treated, if appropriately combined with the metallurgical test work, may improve gold recoveries. .This paper outlines the mineralogical techniques f or the study of gold ores and metallurgical products and describes the gold mineralogy in relation to its metallurgy. An effective plan for studying refractory and other difficult ores, combining metallurgical test work, chemical analysis and mineralogy and capable of giving positive results over relatively short periods of time, is suggested.IntroductionFactors affecting gold recoveries are of a mineralogical nature and include (i) the gold-bearing minerals, (ii) their grain size and, particularly where the grain size is very fine (10 microns in diameter and less), (iii) their host minerals and (iv) the association these form with the gold-bearing minerals.Mineralogical studies of gold ores and metallurgical products containing gold in economic amounts (today down to 1/10 of one ounce per tonne or 2.84 ppm) are difficult and time consuming. Mostly because of such reason, metallurgical testing (test work) is usually done simply by trial and error without understanding the causes for failure or success.Mineralogical studies, if appropriately conducted and combined with the test work, provide an efficient mean s of improving recoveries through the understanding of gold losses derived from the use of the wrong technique for separation. The information they provide is therefore the first step in the development of recovery techniques, for those ores where the test work alone failed to produce positive results."

Jan 1, 1983

By T. Norvell, R. Gosine, S. O’Young

"This paper describes the use of dynamic scheduling and discrete event control to provide coordinated control of multiple automated vehicles. This work has been carried out within ongoing research into multi-robot coordination developed around the underground mining scenario. Demonstrations using scaled laboratory models of underground mines illustrate the potential for this technology for full-scale implementation for mine-wide automation. IntroductionIn the past decade, the mining industry has been improving the efficiency of underground mining operations. Robotics and automation have demonstrated the potential to further reduce costs. Tele-operation of underground vehicles from above ground and autonomous navigation have reduced travel delays and allowed for single operator control of multiple vehicles (Bloomquist and Hinton, 2001). Other recent projects include the automation of the digging process as well as the drilling and blasting operations. Infrastructureless guidance systems are also being developed (Bloomquist and Hinton, 2001).Mine-wide automation requires significant developments at two levels: (1) the development of mining robots capable of performing tasks either autonomously or semiautonomously; and (2) the development of methods for automating operations at a systems level. This paper focusses on the latter, and describes a general framework for the coordination of multiple mobile robots in an unstructured or semi-structured environment."

Jan 1, 2003

By Y. Chengxian, F. Yaorong, Xinzhe. L.

Many factors about the HIC (hydrogen-induced cracking) resistance of pipelines are discussed in this paper. The main factors that influence the ability of HIC are environmental and material factors. The chemical compositions, non-metal inclusions and microstructure are discussed in detail, while a group of tests on HIC resistance are done according to varying C, S, Mn and P contents in pipeline steels, different experiment time and different strength to the coupon. It is concluded that decreasing the amount of C and S can obtain good HIC resistance; the test time has an effect on the different microstructure of X70; microstructure is the most sensitive factor for the initiation processes of HIC.

Jan 1, 2005

By R. D. White

"The Cumberland Basin of Nova Scotia has long been considered a structural basin by virtue of the elliptical outcrop and inward dip pattern of the Pennsylvanian outcrops. Recent published and unpublished data indicate that subsidence began in the late Devonian, perhaps resulting from a graben or rift. The Mississippian sediments which filled the growing depression were continental, lacustrine and marine with evaporites. The cessation of the riftforming processes is recorded by the alluvial swamp-type sediments of the Pennsylvanian which filled the depression. In excess of 25,000 feet of Carboniferous rocks are believed to be present in the deepest part of the Basin. Starting with the rift hypothesis, we can speculate on the kinds of sediments, their location and the structural features present beneath the Pennsylvanian surface. Using surface exposures and a limited amount of subsurface data, we theorize that (1) the Mississippian evaporites acted as glide zones which effectively divided the Basin into two horizontal structural layers. The rocks above the evaporites, responding to Appalachian stresses, formed the long diapiric folds with cores of overthickened evaporites. Below the evaporites the structures are related to movements of the rift floor, compaction closures and structures formed by differential horizontal movements of the rift walls. (2) The rift, in its deeper parts, will have more and a greater variety of marine rocks than the outcrops indicate. Should the rift hypothesis be correct, the possibility of finding hydrocarbons is enhanced."

Jan 1, 1972

By James R. Hein

Manganese nodules form at the sediment surface of abyssal plains throughout the global ocean at water depths of about 4000-6500 m. The nodules form a continuum from purely hydrogenetic (all metals from seawater) to purely diagenetic (all metals from sediment pore waters), which will determine which metals of potential economic interest are enriched in the nodules. Another important factor in metal enrichment is whether diagenesis in the bottom sediment is oxic or suboxic. There are several nodule fields in the deep ocean that have received much attention with regards to economic potential, the most important being the Clarion-Clipperton zone (CCZ) in the NE Pacific, where the International Seabed Authority (ISA) has signed 12 contracts for exploration areas, each spanning 75,000 square kilometers. Those nodules are rich in nickel (mean 1.3 wt. %), copper (mean 1.1 %), and manganese (28%), with moderate amounts of cobalt (mean 0.2%), molybdenum (587 g/t), and lithium (129 g/t). A conservative estimate is that there exists 21,100 million dry tonnes of nodules in the CCZ, yielding more manganese, twice the nickel, three times the cobalt, and four times the yttrium than the entire land-based reserve base (economic plus marginally economic plus subeconomic reserves) for each metal. Total rare-earth elements (REEs) as oxides average 0.09% in CCZ nodules, a potential byproduct even at that grade because the heavy REE complement averages 26%, compared to less than 1% for the large land-based carbonatite REE deposits. The price for HREEs is much greater than for the light REEs. For comparison, the REEs in deep-ocean ferromanganese crusts are 3 to 5 times greater than nodules and the HREE complement averages 18%. Of the 12 CCZ contracts, 7 are with States (China, France, Germany, Japan, Korea, Russia, and a group of States (IOM); and 5 are with companies: G-Tec Sea Mineral Resources NV, Nauru Ocean Resources Inc. (NORI); Tonga Offshore Mining Ltd (TOML), UK Seabed Resources Ltd (Lockheed UK), and Marawa Research and Exploration Ltd. Three other nodule fields that have received attention are in the Peru Basin, which has nodules very rich in manganese (34%) and lithium (mean 311 g/t), the Penrhyn Basin (Cook Islands Exclusive Economic Zone), with nodules very rich in cobalt (mean 0.4%); and the Central Indian Ocean Basin (CIOB), where India has an exploration contract with the ISA. CIPB nodules have mean nickel, copper, and manganese contents of 1.1%, 1.0%, and 24% respectively.

May 1, 2013

By Brad Ross

? Value in number of children ? Polygamy common ? Support of extended family and friends ? HIV/AIDS ? Not a culture of savings ? Minimal mechanical experience ? Supportive ? Unintended hindrance ? Mining claims ? Export Permits Lack of funding

May 1, 2011

Sherwood?s Minto Project ? High grade copper copper-gold deposit ? Yukon Territory, Canada ? Development underway ? Permitted ? Production by mid mid-2007 ? 40 40-50m lbs Cu plus Au/Ag by by-products ? Parallel exploration program underway ?Discover more high grade resources ?But what kind of deposit is it?

May 1, 2006

By Robert B. Parsons

"For the fourth time in five years, residents of northern Canada have seen a change in the tax treatment of housing and travel costs. The latest changes announced in December 1990 by the Minister of Finance are to become effective in 1991. When will the tinkering stop?IntroductionFor man y years prior to 1987, certain travel and housing allowances received by employees in remote areas were generally considered by Revenue Canada to be tax-free, even though some observers suspected that such generous treatment was contrary to the provisions of the tax legislation. In the mid-eighties, Revenue Canada decided to reconsider the tax treatment of the mining industry's long standing practice of providing housing and travel assistance to these employees. The tax- free treatment was continued by virtue of annual remission orders, but only pending the enactment of legislation which would tackle the issue head-on and layout the rules in black and white to be seen by all. The sequence of events since then may be chronicled as follows:February 26, 1986-Finance Minister Wilson's budget present s the framework for the future tax treatment of travel and housing benefits provided to residents in remote regions of Canada.December 22, 1986-The Minister of Finance announces detailed rules to fill in the earlier announced framework.January 1, 1987-The new tax rules come into effect.April 29, 1988-The Minister of Finance announces the establishment of a Task Force to examine the existing criteria for determining the eligibility of residents of northern and isolated areas for tax benefits.October 27, 1989-The Task Force presents its report.December 7, 1990-Finance Minister Wilson announces a new system of tax benefits for residents of Canada's northern and isolatedregions.January 1, 1991-The new rules become effective."

Jan 1, 1991

By J. A. Chamberlain

DURING a recent trip across Canada and parts of the northern United States, the. writer examined some forty mine models. Construction -details and the uses to which the models were being put were outlined in a report to Eldorado Mining and Refining, Limited, and a specific model was proposed on the basis of the Company's particular needs at their Beaverlodge operation. It was felt, however, that portions of the report would be of some value to anyone contemplating building a mine model. For this reason, a synopsis of some of the more important aspects of the problem is presented here, together with a suggested model type that appears to have wide application. Thanks are due not only to Eldorado for permission to publish the following material, but also to the many mine personnel across Canada who allowed the writer to examine their models and gave freely of their time in discussion.

Jan 1, 1958

By S. Nafisi

Permanent mould casting may be regarded as a near net shape manufacturing process where simple to very complex shaped engineering components are fabricated with high degree of precision in a metallic mould, In this group, High Pressure Die Casting (HPDC), have attracted more attention because of its production rate, where both liquid and semisolid metals (SSM) can be cast with high degree of precision and versatility. The SEED process, Swirled Enthalpy Equilibration Device, the new process for semi solid metals slurry production route, consists of two steps: The initial step involves extracting specified amount of heat from the molten metal to generate liquid-solid slurry, i.e, mushy structure, followed by drainage of remaining liquid to produce a compact free standing feedstock for rheocasting operation. In this paper, microstructural evolution during the process and some initial casting results of automotive components an also reported.

Jan 1, 2005

By Warnett Kennedy

"GENUINE CONCERN for the environment is a built-in attitude of mind. If you do not have it by age 40 you probably never will. Some people speak the jargon of 'environment' and 'ecology' for political reasons, others because it feeds their need and bias toward attitudes of moral indignation or dissent. Others pay lip-service for purely business reasons. Complete reactionaries equate conservationists, ecologists and environmentalists as either 'commies' or 'pinkos'. Their real credo is the old saying, ""Where there's muck there's brass."" Those who have genuine concern for good environment are not only romantics like Thoreau but realists who sense the danger to our planet if human greed is rampant and unchallenged. The cities are in real trouble. Almost 75 per cent of the population already live in and around cities. Even mining men live in cities or bring up their children in the new 'instant' towns. The ecology of cities is the concern of all. Our distinguished guest Stewart Udall, in his book ""The-Quiet Crisis,"" quoted Thoreau in 1859 as having written ""each town should have a miniature wilderness park, a primitive forest of five hundred or a thousand acres where a stick should never be cut for fuel, a common possession forever."" Mr. Udall will be glad to know that this advice was taken in at least one instance known to me. I refer to Stanley Park in Vancouver. It is a primitive forest of 1000 acres right inside our small downtown peninsula. It remains unmanicured. This month we celebrated the completion of a seawall of 4%, miles along its perimeter. The construction of this wonderful walkway started in 1910. We are very, very proud of our park."

Jan 1, 1972

Energy benchmarking is widely applied across industries to determine the potential to improve energy performance. Unlike the many technologies for which energy benchmarks and efficiency rating systems are already in maturity, benchmarking of mining processes is still in its infancy. Benchmarking energy usage in mining operations, where energy costs are high and represent a significant portion of overall operating expenses, is challenging due to the uniqueness of each mining operation. Mines vary in terms of geology, geographic setting, ore body geometry, mineralogy which impact the mining method, material handling, processing and waste management. In order to gauge the opportunity for reducing the energy intensity of individual operations and also to compare the energy performance of operations on a global scale, the deployment of new benchmarking methodologies, models and frameworks is necessary. As a step towards the establishment of an accurate framework for benchmarking the energy consumption of mining operations, comminution, one of the more energy intensive mining sub-processes, was selected as the focus of a new energy benchmarking method. The methodologies and processes used to onset fragmentation in a rock mass to the crushing or grinding of rock to a size that is suitable for economic extraction are predominantly dependent on the ore properties. For this reason, site specific factors, such as the size reduction requirements and ore hardness were included in an energy benchmark model so that the energy performance of comminution processes at different operations could be normalized and compared on a global scale. Single particle compression breakage has been identified by several prominent researchers in the field of comminution as the upper limit of energy utilization in size reduction processes. For this reason single particle compression breakage was proposed as the basis of a work index for ores to be used as an input for the benchmark model. Overall, the new method showed that the energy benchmark for mineral comminution can be normalized and subsequently compared for a range of mining operations once the ore hardness has been appropriately characterized.

Aug 1, 2013

By E. T. W. Bailey

A HISTOR Y of the development and application of instruments, from the simplest U gauge to a modern indicating recording controller, would contain many interesting accounts of difficulties experienced and over-come. Important as is the history of development to any branch of science, this phase will, of necessity, have to be omitted from this paper and remarks confined to the results from the use of instruments in their present form. The steel industry bas, in the past decade, become increasingly instrument minded. More than ever, economy and adherence to doser specifications are demanded, and any tool that will aid in attaining these objectives by intelligent application and use finds a ready acceptance. The open-hearth furnace bas offered a field for instruments which is different from almost any other and one in which even a small percentage saved in operating costs may represent a considerable sum. Nevertheless, this department of the steel industry has been more cautions than most others in accepting the benefits which automatic control bas given on many other types of industrial furnaces, and one is puzzled why open hearths have not more generally benefited by the application of controlling instruments. The furnace operator bas to adjust the same three main valves that control fuel, combustion air, and stack draft as on most other furnaces, with the additional regulation of reversing the furnace. He is just as aware of the importance of proper draft control and correct air volume to burn most economically the applied fuel as any good boiler-plant engineer. What, then, are the special conditions that pertain to the open-hearth furnace?

Jan 1, 1939

By J. R. Donald, K. Scholey

"Nickel has been mined and processed from the Sudbury basin for over 100 years. During this period, the process has evolved into what is one of the largest and most complex mining and metallurgical facilities in the world. This paper will describe the geology and mining of the Sudbury basin as well as the Copper Cliff metallurgical flowsheet circa 2005, including:•,Clarabelle Mill,•,The flash smelting furnaces,•,The bulk converters,•,Matte casting, separation, and processing•,The carbonyl refineries•,Carbonyl residue processing•,Copper processing•,Sulphur productsThe challenges of today and the opportunities for the future are discussed."

Jan 1, 2005

By K. Yoshida

Recently, light magnesium alloy with superior heat radiating ability has been attracting attention in various fields. However cold plastic working of the alloy is very difficult and hot working necessary. Furthermore, the magnesium of products with complicated shapes is difficult, the processing cost is high, and the applicability of the alloy is limited. In this study, a technique for obtaining fine wires and tubes by cold drawing is examined to obtain wires and tubes with high strength, quality and surface morphology, while decreasing production cost. In addition, the shearing strain of magnesium alloy wires and tubes drawn under various drawing conditions was calculated by FEM analysis. It was clarified that cold drawing of magnesium alloy is possible. It was also demonstrated that greater reduction of the cross-sectional area could be realized during cold wire and tube drawing by optimizing the drawing conditions.

Jan 1, 2006

By R. Le Houillier, M. Nagamori, A. J. Plumpton

"Asbestos tailings are a typical serpentine, hydrated magnesium silicate, consisting primarily of antigorite and a few per cent of unrecovered fibrous chrysotile. Serpentine has unique thermal properties in that dehydroxylating calcination at 600 to 700°C can yield an amorphous structure in which most of the magnesia is liberated from the original bond with silica and thereby rendered chemically active. The amount of activated magnesia can be quantified by selective leaching with a weak acid such as acetic acid. Many wet processes have been proposed to extract magnesium values from calcined or natural serpentine by means of various acids and their ammonium salts. However, the only commercial utilization of serpentine today is found in dry processes such as the production of fused magnesium phosphate fertilizer .The present paper reviews the physical chemistry of the dehydroxylation of serpentine and also various wet and dry processes in order to provide a general view regarding the chemical transformation of asbestos tailings.IntroductionAsbestos fibers occur as chrysotile, a serpentine polymorph. More than nine tenths of mined asbestos ores consist of massive non-fibrous serpentine, primarily the polymorph antigorite, which is discarded as tailings after fiber extraction. For many decades, Quebec has been a world leader in the production of asbestos fibers. As a result, colossal tonnages of serpentine have accumulated in the Eastern Townships'!'. Serpentine minerals are found in large deposit s throughout the world, and significant research efforts have been made, particularly in Japan and the USSR, mostly in attempts to extract magnesia or silica values therefrom.The chemical composition of serpentine (chrysotile and antigorite) may be ideally expressed as Mg3Si2Os(OH). which corresponds to 43.7% MgO and 43.3% SiO2. Natural serpentines often contain a few per cent of Ni-bearing magnetite and other impurities, and therefore the contents of MgO and Si02are both about 40% or lower.Serpentine (hydrated magnesium silicate) is virtually insoluble in weak acids. However, when dehydroxylated under controlled conditions, ' it decomposes to an amorphous state in which magnesia and silica are isolated and chemically active. The magnesia so activated is readily soluble in weak acids. This unique characteristic of calcined serpentine, first discovered in 1942,, has since attracted the attention of innumerable researchers, whence many processes have been proposed."

Jan 1, 1980

By R J. Tremblay, R. R. Hoffman

This paper deals with materials of construction and problems encountered and overcome in leaching and filtration of oxidized sulphuric acid slurry in the Port Radium mill after eight years of operation. The slurry is characterized by a high calcium sulphate content as well as a high chloride level under oxidized conditions, both of which affected initial design and subsequent changes. Leach agitation tanks are of wood with a mild steel superstructure and stainless steel agitator and moving parts below solution level. Electro-polished 316 stainless steel cooling coils are used for temperature control of the slurry. The string filters are of the Oliver type with wood decking. Extensive use is made of wood, Linatex lined mild steel and stainless steel for the slurry handling. A typical analysis of the slurry solution follows:(pH-1.30) ClOa Fe+++ Free Acid UaOs c1-so.--0.10 gms/litre 10.2 gms/litre 6. 7 gms/litre 3.5 gms/litre 2.0 gms/litre 155 gms/litre

Jan 1, 1961

By H. E. T. Haultain

I HAVE considerable hesitation in preparing and presenting this paper. These machines have been such an intimate part of my own experiences and predilections for such a long time that J would find it difficult to tell the story in an impersonal way. They have had several attractions for me. They were needed for the study of the fundamental features of modern milling, size analysis and accurate batch concentration of the very fine particles. I had been a millman once, a real operating millman, and, when I became academic". I always had the craving to link the academic laboratory with the field, as Rittinger and Richards had done. My first milling experience was with a small concentrator at a tin mine in Bohemia, forty-seven years ago. There was no assay office and the testing of our tailings was by means of a "Vanning Shovel", introduced from Cornwall by Captain Josiah Thomas, the great Josiah of Dolcoath, some fifteen years previously. This was a most effective instrument and it has always been a puzzle to me that it has not been more universally used by millmen. Later, at Freiberg, on the other side of the Erz Gebirge from the tin mine, I was introduced to the "Sichertrog", made out of wood shaped something like a very shallow boat or an elongated saucer, a most effective piece of apparatus when. the difficult technique of handling it was once achieved. Later, in the Slocan in British Columbia, my partner, the late Maurice Bucke, used a short length of flat trough or launder suspended by four wires, with which he got very satisfactory results as a small batch concentrator. In the University laboratory we had frequent need for something of this kind, and many efforts were made to solve the problem. With W. E. Johnston, we were working on the problem of gold-bearing telluride ores, which called insistently for a separation of the very fine telluride particles which existed only in minute quantities in the Kirkland Lake ores. Under this spur there finally developed the Superpanner, which is a mechanized combination of the Vanning Shovel, the Sichertrog, and the Maurice Bucke suspended launder.

Jan 1, 1937

By W. Hrynewich

"The Central Canada Potash facility, a division of Noranda Metal Industries Limited, is located 3 kilometres south of the junction of Highways 16 and 2, about 75 kilometres south-east of Saskatoon, Saskatchewan. The site occupies 26~ hectares of land and includes well-equipped machine and electrical _shops, a 325,000-tonne muriate storage and reclaim warehouse, a stores warehouse, processing plant (mill), two mine shafts (one for production, the other for servicing and personnel transport), as well as a two track product loading complex. Access to the site is by road and railway (CN and CP Rail). Suppliers of operating and maintenance use both means of transportation, whereas muriate shipments are entirely by railway.Currently five continuous mining machines - one a Goodman 526 borer and four Marietta 911-A units produce some 10,500 tonnes of ore per operating day. A smaller Voest-Alpine Af.1-100 boom type miner is used for floor cutting which was previously done by a production unit. In order to maintain safe, competent ground conditions only 35 percent of the total ore is extracted. At this rate mine reserves are deemed adequate for about 100 years. The plant has operated since August 1969 and has a current practical annual capacity of 1,270,000 tonnes of muriate. As of June 30, 1981, some 11.9 million tonnes of muriate had been produced from 31.4 million tonnes of ore. Of the total muriate, 6.1 million tonnes was granular, 4.8 million was coarse, and 1.0 million was standard. No standard product has been made since August 1978."

Jan 1, 1982

By J. A. Ressinger

"The purpose of this paper is to discuss some of the differences between various methods of excavating and loading as they relate to mining operations. The intent is not to provide ""pat"" answers, but instead to raise some questions and set forth some reasonable guidelines.Specifically, the paper deals with the differences and relative merits of power shovels versus rubber-tired front-end loaders - or, carrying this further, comparing what could be called ""stationary"" loading or excavating devices to ""mobile"" types."

Jan 1, 1972