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By A F. Kravic

Carbonyl nickel powders of irregular particle shape and low a11parent density are used extensively in the production of porous nickel electrodes for nickel-cadmium storage batteries and hydrogen-oxygen fuel cells employing alkaline electrolytes. Such porous nickel matrices are at-tractive for these intended applications as they are relatively inexpensive, are corrosion resistant, have good electrical conductivity, can be welded to form electrical contacts, have a long life (as demonstrated in alkaline storage batteries), and are rugged and vibration and shock resistant. This paper describes a feasibility study concerning the production of porous multi-layer nickel electrodes by the pressing and sintering of stacked layers of green-powder rolled nickel sheet. Background H AUSNER (1) conveniently listed nine different powder compaction processes used for forming metal powders into useful shapes. These are shown in Table I. There are additional powder metallurgy processes; however, most of these are combinations of two or more processes listed in the Table. A study of the literature revealed that every powder compacting process, with the exception of isostatic pressing and explosive forming, has been evaluated or is being used for the manufacture of porous metal electrodes.

Jan 1, 1965

By A. P. Fletcher, K. Croteau

The intent of this paper is to cover some aspects of preventive maintenance methods which have come into wider usage in recent years as a means of increasing operating efficiencies. Particular emphasis is placed on lubrication and related servicing.

Jan 1, 1967

By M. Harrison, C. H. Stockwell

"Metals vah1ed at more than $200,000,000 have been obtained, mainly since 1930, from the mines of northern Manitoba. The greater part of this production has been copper, zinc, and gold from the Flin Flon, Sherritt Gordon, and Mandy mines. The chief mines from which gold alone has been produced are God's Lake, Laguna, and Gurney. At present (May 1947) Flin Flon and Sherritt Gordon are the only producing mines, but the Nor-Acme property is being developed for large-scale production of gold. Large deposits of nickel and copper are being diamond drilled at Lynn Lake, and the Thompson, Ferro, and other properties are being developed. The mineral deposits lie within irregular or elongated areas of Precambrian sedimentary and volcanic rocks, surrounded by granite ( Fig. 1).The common rock types include basic and acidic flows, agglomerate, ruff, greywacke, arkose, argilli te, conglomerate, and their gneissoid and schistose derivatives. They are invaded by sills, dykes, and irregular bodies of gabbro and diorite, and all are cut by granite. Some of the sediments are interstratified with volcanics, and others are deposited unconformably on them.STRUCTURAL GEOLOGYLittle is known of the structures of the rocks in the area as a whole, because by far the greater part is unexplored or has been covered only by reconnaissance surveys. Available information indicates a general east structural trend in the southeast part, whereas in the west part the folding is mote complex with no definite overall trend. However, in a few small areas in the western part where detailed work has been done, as around the Flin Flon, Sherritt-Gordon, Nor-Acme, and other properties, the structure is fairly well known. The following descriptions apply chiefly to these areas ."

Jan 1, 1954

By K. R. Nichol

The author points out that corrosion works 24 hours a day, every day. It is an economic reality that the cost of corrosion is inevitable and that its cost should be incurred in the least expensive way. An economic evaluation technique to properly assess its relative impact is the Discounted Cash Flow Method. Various remedial and corrosion control measures are available and these, when coupled with a planned corrosion control program, help reduce the cost of corrosion.

Jan 1, 1973

By D. Q. Li

"This paper briefly introduces problems that can occur in the design of rare earth separation processes and that require close attention during engineering design. Important factors must be considered include the following. 1) The separation process is primarily based on two points. One is the raw material composition and the other is the product purity requirements. 2) Optimization of the rare earth separation process requires optimization of the flowsheet configuration and each process parameter. 3) The separation of heavy rare earths is performed under non-equilibrium conditions. 4) The radioactive elements uranium and thorium must be removed from the feed to separation. 5) Process economy and environmental protection must be considered together in the evaluation of any separation technology options. INTRODUCTIONThe importance of rare earth (RE) is well recognized in high-tech applications and sophisticated national defense technologies. RE is the treasure house of the 21st Century new materials. The RE separation processes developed using HEHEHP (P507), P507-alcohol (ROH) and naphthenic acid (NA) have been widely applied in China. These processes have led to industrial production of all of the individual RE with up to 4N (99.99%) or higher purity (Li, Wan, Lin, Xie, Lin, & Wang, 1980; Li, Wang, & Xie, 1985; Li, 1995; Li, Wang, Meng, & Li, 2005). In order to achieve the best economic and environmental benefits, this paper discusses several problems to which attention must be paid in the design of rare earth separation process."

Jan 1, 2016

By N. Musee, N. Kornelius

This study presents a neural network approach to modelling the liberation of gold bearing ores. A complete mineralogical analysis of unmilled and milled ores, including gold deportment and gangue content are used as inputs to a self-organising neural net which generates order preserving topological maps. The arrangement and shapes of these clusters are coupled to unmilled free gold data to predict gold liberation in milled ores (absolute error: 4.2%). Moreover, the self-organising maps were diagnostic of the quality of data used, indicating that the relationship between particle size and gangue material content requires further investigation.

Jan 1, 2005

By J. Trojacek

A large-scale development in exploration and production of uranium ores in the Czech Republic was done in the 2nd half of the 20th century. Many uranium deposits were discovered in the territory of the Czech Republic. Over a period of 50 years approximately, 110 000 tons of uranium in concentrate were produced. Different mining methods were developed and used. One of the most considerable deposits in the Czech Republic is the site Hamr na Jezere ? Straz pod Ralskem where both mining methods ? the underground mining and the acidic in-situ leaching ? were used. The extensive production of uranium led to widespread environmental impacts and contamination of groundwaters. Over the period of ?chemical? leaching of uranium (ca. 32 years), a total of more than 4 million tons of sulphuric acid and other chemicals have been injected into the ground. Most of the products (approximately 99.5 %) of the acids reactions with the rocks are located in the Cenomanian aquifer. The contamination of Cenomanian aquifer covers an area larger than 27 km2. The influenced volume of groundwater is more than 380 million m3. The total amount of dissolved SO4 2- is about 3.6 million tons. Approximately 0.5 % of the contamination is located in the Turonian aquifer. After 1990, a large-scale environmental program was established and the Czech government decided to liquidate the ISL Mine and start the remediation in 1996. The remediation consists of contaminated groundwater pumping, removing of the contaminants and discharging or reinjection of treated water. The objectives of the remedial activities are the followings : to restore the aquifer to a condition guaranteeing continuing usability of Turonian water of Northern Bohemia Cretaceous, to decommission boreholes and surface installations and to incorporate the surface of leaching fields into the ecosystems taking into account regional systems of ecological stability and urban plans. Nowadays four main remedial technological installations for reaching of these aims are used - the ?Station for Acid Solutions Liquidation No. One?, the ?Mother liquor reprocessing? station, the ?Neutralization and Decontamination Station NDS 6? and the ?Neutralization and Decontamination Station NDS 10?. Total capacity of this complex is sufficient to reach the target values of remedial parameters in 2037. The remediation action consists of: pumping of residual solution to the surface, separating uranium from the solution and reprocessing contaminants into commercially usable or ecologically storable products. It is expected that the amount of withdrawn contaminants will vary from 80 000 to 120 000 tons per year. Total costs of all remediation activities are expected to be in excess of 1.5 billion EUR.

Aug 1, 2013

By R. T. Erskine

"The No. 6 orebody is located 6 miles from the main op.eration of Brunswick Mining and Smelting Corporation Limited and includes open-pit and primary gyratory crushing facilities. Ore is transferred by truck to the secondary crushing facility at the main plant. About 3,500 tons of ore per day are crushed to minus % in. and ground to 68 per cent minus 400 mesh in rod and ball mills for flotation feed. Conditioning and aeration precede rougher flotation, and four stages of cleaning bring concentrates to a grade of 42 per cent Pb + Zn + Cu. Middling products are reground and refloated in a secondary flotation circuit, producing a cleaner feed and a final tails product. Primary bulk concentrate is treated with sulphur dioxide and steam-heated to l 70°F and the majority of the gangue is floated off, leaving a product that assays 57 per cent combined Pb + Zn + Cu and is suitable for marketing. This material is thickened, filtered, dried and loaded into railway cars for shipment to the smelter. Reagent use on flotation is conventional, with many compromises in dosage required to maintain the recovery of lead and zinc in the most advantageous proportions. Many refinements in the flowsheet have been made since start-up in 1966, and more may be made as laboratory and plant testwork indicate possible improvements."

Jan 1, 1971

By O. Babak, J. G. Manchuk

ABSTRACT A significant factor in evaluating bitumen recovery from an oil sands mine is the particle size distribution (PSD). Increased understanding of mined ore quality and improvement in predictions of recovery can be achieved through PSD modeling. This paper addresses PSD modeling using geostatistics. PSDs may be described using many discrete particle sizes, making this a challenge. The approach parameterizes PSDs with a few statistics. A lookup table is used to reconstruct the PSDs based on models of the statistics. The workflow is applied to Total E&P Canada’s Joslyn Lease and yields good results that reproduce input statistics without introducing artifacts.

Jan 1, 2013

By J. C. Beidelman

One of the oldest settled portions of Canada is that "strip of land" extending into the Gulf of St. Lawrence, known as the Gaspe peninsula, with the Bay of Chaleur on its southern boundary. This "strip of land" is still so very sparcely populated that only at a few places does settlement extend more than a few miles from the coast. ? The peninsula is 160 miles long, 75 miles wide and with the exception of the above mentioned settlements is a mountainous wildness-void of all roads or inhabitants. Developments in the interior, of all nature, out-side of the cutting of timber by limit holders, was entirely lacking until the year 1915, when mining was first commenced. In the summer of 1844 Sir William Logan made a preliminary survey across the peninsula, from Cape Chat on the Gulf of St. Lawrence to Cascapedia on the Bay of Chaleur, passing through a country ?of which very little was known at that time. After a rather rough trip to the headwaters of the Grand Cascapedia river, Logan's party descended this river to its mouth, passing ten miles west of what is now known as the Federal mines. There is no record of Logan, or of any of his party, finding zinc or lead ores of any character on their journey across the peninsula, and until 1909 no precious or base metals were discovered within reasonable distance of Logan's survey.

Jan 1, 1924

By S. Kelebek, E. Yalcin

"Diethylenetriamine (DETA) and/or triethylenetetramine (TETA) are reagents that can generally be categorized under ""flotation modifiers"". These polyamines are known to be effective for the deactivation/depression of pyrrhotite that is present in Canadian nickel-copper sulphide ores in large quantities. Recent bench scale testing on some of these complex ores indicated that chalcopyrite flotation can also be adversely affected under certain conditions involving polyamines, which may be taken to be an evidence of their specific affinity towards chalcopyrite. In general, DETA shows no significant depressant action on chalcopyrite while TETA's promotion of hydrophilicity for this mineral has been observed even in the presence of xanthate. This prompted an investigation on thermodynamic equilibria involving these polyamines and copper ions. Results serve a useful purpose to identify conditions for deactivation phenomena. CuDETA2+ and CuTETA2+ chelates as products of sequestration have large predominance areas covering a wide range of redox and pH conditions, where copper xanthate species are not stable, especially in the presence of TETA."

Jan 1, 2009

By V. Songmene, A. Tahan, J. P. Michaud

The machining of thin wall parts, often used in the aeronautical industry still creates a number of problems, including panel deformation. Quality and productivity are often affected. This study seeks to determine the optimal conditions for cutting in order to guarantee a competitive fabrication of parts while still maintaining quality and delivery deadlines. The studied model (Spar) is a typical structural part used in the assembly of airplane wings. The main objective of this study was to improve two performance aspects: surface quality finish (quality criteria) and the rate of cutting by stock removal (economic criteria). To achieve this objective, we used an evaluation process of the geometrical error issuing from the machine-tool. We also determined the stability zones of the machine-tool's dynamic system. Finally, a series of high-speed machining tests (finishing cuts) were conducted using an experimental structured approach (16 000 - 24 000 rpm). Profile measures of surface roughness and cycle times registered during trials allowed us to establish optimal cutting conditions. Surface roughness improved as well as cutting by stock removal. Four parameters were taken into consideration: axial depth of cut, chip load, spindle speed, and cutting fluid. Finally, the influence of the type of cutting fluid was evaluated to show that it did not significantly affect machining results.

Jan 1, 2006

By Roméo Roussin

"The yearly production from the Asbestos Hill pit is 1,550,000 tons of asbestos ore, with a yield varying between 18 and 20 % . The orebody was exposed at the top of a hill, and initial production started without having to remove any overburden. The projected ratio of barren rock to ore, based on the present orebody, was 2 to 1. However, as it was necessary to push back the upper benches, this ratio has changed to 3 to 1. The final pit will be 2,300 feet long by 1,000 feet at the longest and widest points. The final depth will be 680 ft. A pit slope stability study was carried out and an average wall angle of 60-70 degrees must be maintained. Preshearing of final pit limits will produce good wall stability. Permanent access ramps will be 60 ft wide, with an 8 % maximum grade. Geological conditions and the low rock temperature are the major causes of the operation's drilling and blasting problems."

Jan 1, 1976

By A. D. Dalvi

Economics, Resources, Environment and Technology are the major driving forces in the base metals industry. However, these factors are intertwined and together will propel the industry in the future. The demand for metals has grown with economic expansion, between 2 to 4 % p.a. The current growth cycle has been driven by economic expansion in China where the demand for base metals has risen from - 7 % of the world demand in the 90's to - 25 % of world demand today, and rising. Base metals are commodities and their demand and price are cyclical. Historically metal prices have declined in constant dollars, forcing the industry to reduce costs, increase productivity and increase the scale of operation for economies of scale. Due to resource depletion and capacity expansion the industry is driven to expand its reserve and resource base. However, in the case of sulphide deposits of copper and nickel it appears to be a losing battle. For nickel the laterites represent a vast source at this time. Their development requires development of new technologies to make these resources economic. Emission reduction is being increasingly mandated in most jurisdictions with all governments enacting progressively more stringent regulations. The industry has been responding with technological innovation. With the Kyoto protocol there is a push to reduce energy intensity in metal production. Technological innovation is driven by all the other factors and is leading to novel ways of doing exploration, mining and processing, that would maximize resource delineation and utilization, reduce costs, increase productivity, reduce energy consumption, maximize asset utilization and reduce environmental affects. Development of alternative technologies such as Pressure Acid Leach of laterite for nickel, bio-leaching, heap leaching, SX-EW etc are being adopted to achieve the aims of the industry.

Jan 1, 2005

By D. K. Matlock, D. J. Hamre, J. G. Speer

Ultrafine ferrite (UFF) grains may be produced in surface layers of plate steels using controlled intermediate cooling followed by deformation. Experiments were conducted using a 0.12 C - 1.26 Mn steel on a Gleeble 1500 hot deformation simulator. Taguchi designed experiments were used to evaluate prior austenite grain size, intermediate cooling rate, intermediate cooling temperature, intermediate hold time and amount of reduction in order to observe the effects of variables and their interactions on the final microstructure while minimizing the number of required test runs. Evaluation of resulting microstructures and mechanical properties revealed a preferred thermal and mechanical history for developing ultrafine microstructures in surface layers of plate steels. Application of the fundamental concepts of phase transformations to industrial plate rolling is considered.

Jan 1, 2004

By Horace Freeman

"IN THE writer's opinion, the most important industrial re-search problems in Canada concern development of technology for the treatment and commercial utilization of the recent discoveries of v.ast quantities of easily concentrated iron ores in both eastern and western Canada. They exist in both magnetite and hematite forms. The subject is doubly important because of the lack of metallurgical coking coal in Canada. Methods for utilizing our lower grade eastern and western coals for reduction purposes must be developed. We are fortunate in our supplies of oil and gas, which can supply the heat requirements for processing or for thermal electric plants, which are now competitive with hydro-electric plants in the industrial areas. These are among the reasons which have prompted the writer to continue the development of the co-current rotary kiln direct-reduction process outlined •in his report to this Institute at the 1956 Annual Meeting ( 1) in the face of the scepticism which has surrounded the numerous costly failures in 'sponge' or 'direct' iron production. The work involved in bringing the concentrating ores of Canada to the metallic state involves, firstly, concentration of the ores; secondly, preparing the concentrates for reduction; thirdly, reduction of the 'reconstructed' ore; and finally the steel making process. These briefly will be dealt with in order, giving emphasis to the most important of these steps, the reduction process which is the main subject of this paper."

Jan 1, 1959

By B. Ignasiak

Laboratory studies suggest that improvements of coke strength brought about by pre-heating caking coals before carbonization accrue from inadvertent oxidation rather than from other low-temperature changes in the coal mass. Controlled oxidation of highly caking coal, followed by laboratory carbonization, produces cokes which, in terms of a laboratory scale tumble test index, are equivalent to those obtained from prime metallurgical blends. Appropriately formulated blends of exhaustively oxidized and fresh caking coal similarly yield cokes with strength indices comparable to those of cokes made from the same coal after oxidation under optimum conditions.

Jan 1, 1979

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 B. K. Gorain

Barrick' s Buzwagi copper-gold deposit in Tanzania comprises oxide, saprock and sulphide mineralized zones averaging approximately 0.058oz/t gold, 0.13% total copper and 0.03% cyanide-soluble copper. A comparative evaluation of the project based on two potential flowsheet alternatives is presented. The first flowsheet included a gravityconcentration and carbon-in-leach (CIL) plant. The second flowsheet was based on a Gravity-Flotation-CIL plant, which proved to be more economically robust. Selective flotation of copper minerals to produce a saleable copper concentrate proved to be challenging. Detailed characterization of the Buzwagi deposit was carried out through understanding of ore mineralogy, mineral liberation, floatability and selectivity, reagent chemistry and regrinding issues. With this insight, a flotation concentrate of greater than 25% Cu was achieved, recovering a significant amount of copper minerals and tellurides. The overall economics of the project improved significantly with the addition of flotation. Leach tests on gravity and flotation tailings showed an overall increase in gold recovery of approximately 6% for a Gravity-Flotation-CIL plant compared to that for a Gravity-CIL plant.

Jan 1, 2007

By R. V. Fox, L. K. Sinclair, D. L. Baek

"In this study, rare earth elements were recovered from bastnasite concentrate and waste fluorescent lamp phosphors using supercritical carbon dioxide extraction with a nitric acid/tributyl phosphate adduct. Several pretreatment methods were used to alter the crystal structure of the source materials, and thus improve rare earth element recovery. Pretreatment methods included 1) dry roasting of the source material at 730oC, 2) decomposition with 50% sodium hydroxide solution at 150oC for 4 hours, and 3) decomposition with 12 M sulfuric acid at 300oC for 4 hours. Treated and untreated samples underwent supercritical extraction at 24 MPa and 65oC for 1 hour. Untreated bastnasite and phosphor samples showed <10% rare earth element recovery, but sodium hydroxide digestion resulted in >60% recovery for most rare earth elements. Dry roasting of the bastnasite concentrate was also effective, resulting in >60% recovery for cerium.INTRODUCTIONRare earth elements (REEs) consist of the 15 lanthanides, scandium, and yttrium. Scandium and yttrium are included because they are in the same group as lanthanum, appear in many of the same ore deposits as the rest of the lanthanides, and exhibit many similar chemical properties. REEs are used in a wide array of applications including electronics, magnets, catalysts, glass, and solid-state lighting (Xie, Zhang, Dreisinger, & Doyle, 2014). Because of China’s continued dominance of worldwide REE production, the United States Department of Energy has sought to diversify domestic supplies of REEs (United States Department of Energy, 2011). A key part of this strategy is the development of improved extraction methods for both ores and recycled sources.Supercritical fluid extraction (SFE) is a promising technology for extraction and separation of rare earth elements. Contact with an acid adduct dissolved in supercritical carbon dioxide allows for the rapid extraction of REEs from solid matrices. Supercritical CO2 has several potentially useful properties as a solvent, including high diffusivity and the ability to tune solvation properties by adjusting pressure. Such tunability may have applications in separating the REEs once they have been extracted from the solid phase. Tributyl phosphate/nitric acid adducts (TBP:HNO3) are a particularly promising class of adducts for SFE extraction of rare earth elements. Using TBP:HNO3 adducts in supercritical CO2, several researchers have successfully extracted REEs from their oxides (Wuhua, Pijia, & Yongjun, 2010; Zhu, Duan, Xu, & Zhu, 2009). However, there is a complication in applying this technique to many types of ores and recycled sources: REEs are often locked in refractory minerals which are resistant to acid attack, resulting in limited recovery in supercritical extraction."

Jan 1, 2016