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By S. Maleksaeedi

On-site evaluation of strength using hardness is common for different materials. The lack of such relation for aluminum alloys has always been felt. In this work, a finite element analysis of plastic deformation and its distribution in Brinell hardness testing is presented. The analysis has been performed for different strength levels of aluminum alloys. By utilizing the Von Mises equivalent strain in hardness, it is tried to derive a correlation between hardness and strength values for the alloys under consideration. The derived correlation is verified using the experimental values available in literature.

Jan 1, 2004

By C. Groccia

As the search for new ore bodies drives mines to be developed at greater depths, the associated high stress environments present challenges for rock support design. Excavations in highly stressed brittle rock are often subject to large volume increases due to rock failure, a phenomenon known as rock mass bulking, which can result in significant wall convergence. Support systems need to be designed to minimize the amount of bulking and to accommodate large wall convergences. In order to design such a support system, empirical guidelines are often used to predict the amount of bulking. However, the empirical guidelines that are currently available are based on a limited number of case studies and consider few input parameters, which may result in an inaccurate bulking assessment. This paper describes methods of collecting quantitative field data at Creighton mine in Canada to better understand rock mass bulking and to further develop the empirical guidelines for bulking assessment for tunnels in highly stressed grounds. Measuring

Aug 1, 2013

By F. K. McKean

Introduction The present paper may be considered as a sequel to a paper, A Process for Cleaning Molybdenite .Concentrate, which was presented by the author at the annual meeting of the Institute last year. In that paper, a description was given of the laboratory work leading up to the adoption of a new process for treating complex molybdenite ores of the Molybdenite Corporation of Canada. A bare outline of mill performance with the new flow-sheet was included. With this writing, the purpose is to describe the highly interesting work of translating laboratory experience into mill practice, to show what changes were required in design to put the scheme on an operational basis, and to point out the gratifying improvements in mill products which resulted from the new procedure. The process has been placed in operation at the La Corne mine of the Molybdenite Corporation of Canada. This mine was operated during the war by Wartime Metals Corporation, and, earlier, by the Molybdenite Reduction Company, which installed a small plant. The property is situated on the highway from Amos to Val d'Or, Quebec. The claims held by the Company are at the boundary between La Corne and Vassan townships.

Jan 1, 1947

By A. H. C. A. Zimmerman

WE have just heard what must be regarded as a thoughtful, constructive and somewhat painful analysis of the financial function of our industry. While thinking about this, it is interesting to reflect on the conditions which have stunted the growth of the financial side of our affairs. Mining must be regarded as a wealthy business. •while immeasurable grub takes and development budgets have been lost, there can be little argument that a productive ore-body nearly always produces the type of wealth that breeds some extravagance. I recognize that this statement can be attacked from many sides, but an historical comparison with a commercial enterprise involving similar investment will demonstrate what I mean. However, these old times are be-ginning to disappear for a variety of reasons. High amongst these are: ( l) Increased costs of exploration. (2) Remoteness of many new finds. (3) Fixed or declining metal prices (particularly when expressed in constant dollars). ( 4) Constant demands for higher wages.

Jan 1, 1962

By Jing Li, Weiqiang Lai, Joe Zhou, Jiezhen Ma, Shuibo Chen, Ashele Copper Company, Feng Gao, Guofu Feng

"Copper-zinc ores often contain gold and silver, which can be recovered into copper concentrate by flotation as by-product. The challenges for operations that produce copper, zinc, gold and silver are the separation of copper and zinc and the low grade of precious metals. Ashele copper-zinc ore in north China contains 2.38% Cu, 0.69% Zn, 0.21 g/t Au and 18.10 g/t Ag and the plant produces copper and zinc concentrates, with gold and silver being recovered into copper concentrate. Copper occurs mainly as chalcopyrite and Zn occurs as sphalerite. Copper is well recovered with a recovery of over 94%. However, the recovery of Zn is substantially low (around 50%) due to fine grain size of sphalerite. In addition, gold recovery is much lower than expected and only 33% of gold in the flotation feed was recovered. The grade of gold in copper concentrate is also lower than the required payable grade (1.0 g/t). To determine the cause for lower Zn and Au recoveries, a plant survey program was conducted on the operation. The information acquired shows that the loss of Zn was mainly in the copper concentrates (accounting for approximately 38% of the head assay); of which, 24% was liberated, 8.5% was associated with chalcopyrite and 4.6% was associated with pyrite, indicating that the separation of copper and zinc was the main cause for the Zn loss, with liberation being the second cause for Zn loss. Future effort in improving Zn recovery should be focused on the separation of zinc from copper. Gold in the ore occurs as both microscopic gold and submicroscopic gold, accounting for 36% and 64% of the head assay, respectively. Microscopic gold occurs mainly as native gold and electrum; it is relatively coarse with a grain size of 10 to 240 µm and a large portion can be recovered by gravity. Submicroscopic gold was mainly carried by pyrite (accounting for 38%), and to a less extent, by tennantite (15%) and chalcopyrite (10%). Gold in sphalerite is nominal (1%). It is suggested that more coarse gold and tennantite be recovered and a gold recovery increase can then be achieved to obtain a copper concentrate with over 1.0 g/t Au through flowsheet optimization. Gravity concentration should be investigated and may be worth added into the existing flowsheet to maximum the gold recovery and grade.INTRODUCTIONCopper-zinc ores containing gold and silver is a subtype of polymetallic sulphide ores. Unlike porphyry copper sulphide ores and iron-oxide copper-gold ores, this type of ores often contains substantial amounts of zinc and lead. Polymetallic sulphide ores are mainly distributed in Canada, such as at the LaRonde and Horne deposits. Other examples include Mt. Morgan in Australia and Boliden in Sweden. Globally, production and reserves from gold-rich VMS deposits account for 1370 t gold. This is equivalent to 1% of the world production and reserves, whereas the Canadian total for gold-rich VMS deposits is 870 t, representing close to 10 % of Canadian production and reserves (Gosselin & Dube, 2005a, 2005b). Flotation is the principal process for processing the copper-zinc sulphides ores, for subsequent smelting, roasting, or hydrometallurgical treatment. Oxidized copper-zinc ores can also be processed using leaching technology. For example, at LaRonde operation (a Cu-Zn-Pb ore containing 3-4 g/t Au and 60-100 g/t Ag) the flowsheet consists mainly of a copper flotation circuit and a zinc flotation circuit followed by a cyanidation process of flotation tails. The precious metals are recovered with copper concentrate, zinc concentrate and cyanidation of zinc tails via Merrill Crowe precipitation (Zhou et al., 2005)."

Jan 1, 2016

By T. Beamish, I. Vasilev, T. Nikolov, E. Marinov, D. Kirilov, P. Barrios

In April 2005, Umicore Copper de-merged from Umicore Group and created a new independent Copper company called Cumerio. As a separate company, Cumerio is a major European copper smelter and refinery and a leading producer of copper products such as wire rod, billets, cakes and specialty rod with a total production capacity of copper products in excess of 500,000 tpy with production plants in Belgium, Italy and Bulgaria. The Pirdop Smelter is the only state-of the-art smelter in South East Europe and it makes Pirdop the natural hub for the copper industry in the region. In order to be competitive in the international market the main challenges facing Cumerio are to maintain its low cost structure and to achieve higher production volumes while reducing its impact to the environment and striving for continuous improvement of the production process. Cumerio's state-of-the-art smelting facility in Pirdop has recently increased the anode production capacity to 250,000 tpy by the installation of the third evaporative cooler on the converters section that allows operating with three-hot converters. In April 2007 a general shut-down for repair and modification on the Flash Smelting Furnace and Waste Heat Boiler is envisaged. At this time a revamp of one of the existing Sulphuric Acid Plants is planned, resulting in a further copper capacity increase to 275,000 tpy with modest Capex. In 2005 Cumerio received from the Bulgarian Ministry of Environment and Water the Complex Permit under the EU IPPC criteria. Accordingly an Environmental Compliance Program was defined targeting a large reduction in the secondary emissions. The system will be commissioned in May 2007. In order to better integrate the smelter and refinery in Pirdop and to respond to the growing demand for cathodes in the region, a new state-of-the-art Electrolytic Refinery with an installed capacity of 180,000 tpy will replace the existing refinery. The new refinery is expected to be fully operational as from early 2008. This paper describes the challenges and the projects.

Jan 1, 2007

By M. Aushouri, S. H. Mansouri, N. Aminizadeh

A thermo-chemical model of the Peirce-Smith copper converter has been developed to predict the molten temperature. The primary assumption of the model was that all matte, slag and gaseous phases in the converter were in thermal and chemical equilibrium. In this model, the matte components were considered only as copper, iron and sulfur elements. In the slag making stage, all the reacted iron was converted to fayalite. The reaction rate of iron and oxygen in this stage was considered to be constant. The converter temperature was calculated by heat balance over time. The model was validated by a detailed comparison with measured industrial data. A good agreement was obtained. The converter temperature depends on process parameters such as oxygen efficiency and molten emissivity.

Jan 1, 2007

By P. Dinham, G. C. Summerton, N. McCulloch, S. Dowling, D. C. Craig

"Development of a process for the treatment of a nickel copper matte rich in the minerals heazlewoodite, chalcocite and bornite has demonstrated significant base metal recoveries and metal separation efficiencies. The determination of chemical and mineralogical changes occurring in the individual leaching stages in laboratory experiments has enabled a better understanding of the complex leaching chemistry. The chemistry and mineralogy of the piloting and laboratory processes are discussed.INTRODUCTIONThe nickel-copper sulfide ores of the South African Bushveld Complex are among the most important Platinum Group Metal (PGM) bearing ores, and contain the world’s largest reserves of platinum. The treatment used in the recovery of PGMs from these ores includes three types of processes, namely ore concentration using physical techniques such as flotation and gravity separation, concentration by pyrometallurgical means, hydrometallurgical extraction of the base metals followed by the PGMs. Following milling of the ore, flotation involves the separation of high value minerals from gangue by taking advantage of the differences in their hydrophobicity. These differences are generally maximized through the use of a surfactant or wetting agent. Concentrates are then thermally treated and melted which brings about physical and chemical changes that enable the recovery of base metals and PGMs. The main aim of the smelting and converting process is to separate and eliminate the valuable metals from the bulk of the unwanted gangue and essentially all of the iron and to concentrate the metal VALUES (into a high grade converter matte. The matte can be further enriched by magnetic separation, producing a PGM-rich magnetic fraction and a base metal-rich non-magnetic fraction. The magnetic fraction is treated by hydrometallurgical processes to produce a PGM concentrate which is further refined to separate and purify the individual metals. The non-magnetic fraction is treated to produce marketable metal VALUES (such as nickel, copper, cobalt and to a lesser extent PGMs. The principal objective of any hydrometallurgical extractive process is to leach the desired elements selectively into an aqueous phase so as to separate them from the bulk of the material. (Crundwell, Moats, Ramachandran, Robinson and Davenport, 2011; Hundermark, Mncwango, de Villiers and Nelson, 2011)."

Jan 1, 2012

By A. Robles-Vega

Personnel of Mexicana de Cobre, a subsidiary of Southern Copper located in Nacozari, Sonora Mexico have been working in the past few years on the development of a process to treat and manage, in an environmentally accepted practice, the residues and effluents generated during the process. To date, this team has been reviewing existing technologies and also has explored new alternatives. At the end of this phase, a novel, efficient and complete process has been configured which will be able to treat some solid and liquid streams such as Teniente converter dust, Peirce Smith converter dust, a Sb-rich precious metals slag, copper refinery electrolyte bleed, acid plant blowdown and an acid bleed of the precious metals plant. The process will consist of a leaching stage, followed by a very selective copper precipitation using novel technology which has been named as back reactions. After copper precipitation, impurities (As, Sb and Bi) will be precipitated mainly as arsenic trisulfide (As2S3) using H2S(g) which will be generated by means of a new process developed in our company. At the end of the process, small volumes of arsenic trisulfide will be vitrified and then disposed as a stable residue.

Jan 1, 2007

By B. Crane, S. Schwartz

"IntroductionThe Cape Breton Development Corporation (CBDC) located in Cape Breton, Nova Scotia, in eastern Canada, was established in 1967. Its mandate at that time was to facilitate a phased downsizing of the coal industry and developing viable replacement industries. The oil crisis in the early 1970s changed CBDC’s mandate and focus was modified to increase coal production to support Nova Scotia Power Commission’s “off oil” policy for their power generators. In the late 1980s the mandate to develop viable replacement industries was eliminated and CBDC became primarily a coal mining company. CBDC presently operates two underground coal mines, Phalen Colliery and Prince Colliery, using a retreat longwall method of mining. Both mines operate beneath the Atlantic Ocean. CBDC also operates associated infrastructure — central workshops, a railroad, coal preparation plant, and international pier. The Need For Substantial ChangeOver the last few years, CBDC has been facing some challenging issues, including improving labour management relations and achieving financial self-sufficiency and profitability. Recent achievements with regard to human resource issues, especially in the areas of collective bargaining, absenteeism, and attendance, show noticeable improvements. All participants should be commended for successfully concluding the collective bargaining process with all four CBDC unions, CUPE; CAW; IAM&AW; and UMWA. However, although these changes are encouraging, even critical in the short term, they are not sufficient to ensure the long-term viability of the company. Market ForcesShort- and long-term financial realities are drawing the need for further substantive changes. The corporation has a mandate to achieve financial self-sufficiency by the year 1999. This goal can only be achieved through a combination of cost reductions and productivity gains, specifically, a reduction in the workforce of 658 and an increase in production of 800 000 tonnes annually. This increase in productivity requires CBDC to re-think the way it does things.In the longer term, CBDC faces even greater challenges. The energy market is becoming more competitive. The electrical utilities across Canada are anticipating deregulation and are positioning themselves for the resultant competition. As primary fuel supplier to Nova Scotia Power Inc. (NSPI), the corporation will have to become ever more competitive to stay in business."

Jan 1, 1997

By S. S. Sephton, Kirit C. Vyas, Melvin J. Greaves

Energy requirements for various pelletizing systems are considered from a fuel and power aspect, with the presentation of typical energy heat balance flow sheets. A partial calculation for the firing zone of a straight grate system is shown and a comparison of an actual measured and a theoretical-calculated heat balance for a grate-kiln is presented. The power used for each pelletizing system and future possible energy savings a1•e also reviewed.

Jan 1, 1976

By I. A. Menshikh, S. A. Kotov, N. L. Shinkarkin

All the cycle for conversion of natural and reprocessed uranium of ROSATOM’s “TVEL” Fuel Company is concentrated at the Siberian Chemical Plant. Conversion capacities are located on two sites, i.e. the Radiochemical Plant, which refines feedstock, and the Conversion Plant, which produces uranium oxides and uranium hexafluoride. Liquid radioactive waste arising in the process, after pretreatment, is transferred to a dedicated national operator for underground disposal. Environmental strategies pursued by the Fuel Company involve the introduction of process solutions intended to eliminate liquid radioactive waste and convert it into a solid phase. In the 5–7 years coming, work will be performed to refurbish and upgrade conversion facilities of the Siberian Chemical Plant that will principally change its radioactive waste management scheme. This paper describes the current waste management scheme and sets out planned schemes for management of natural and reprocessed uranium waste, which will be implemented in the refurbishment of conversion facilities of the Siberian Chemical Plant. The new technologies for the management of liquid radioactive waste from uranium conversion described in the present paper have an undeniable advantage over the current technology mainly due to significantly less environmental harm.

Jan 1, 2020

By L. A. Wrigglesworth, A. S. Dadson

The orebodies of the Giant Yellow-knife mine occur in zones of schist, in an assemblage of typical Precambrian greenstones which form part of the Yellowknife Greenstone Belt. One of the most interesting problems at the mine concerns the fold-like attitudes assumed by the schist zones. The internal structure of the zones and orebodies provides much evidence of folding. A logical conclusion would be that the zones represent a single horizon which has been folded and drag-folded in the ordinary course of mountain building. However, surface mapping, and correlation of certain marker horizons, in underground work, indicate a homo-clinal succession of steeply dipping flows. If this concept of the geology is correct, the zones must cross-cut the regional strike at a small angle and, in the over-all aspect, the regional dip at a large angle. A mechanical interpretation of the zone structure is presented as a suggestion for the present until new evidence is found.

Jan 1, 1959

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 J. F. J. Thomas

"AbstractBoth the quantity and quality of waters available as raw materials are important to Canadian industry and to the national economy. The huge demands of many Canadian industries is illustrated by tabulated figures, based on the 1950 Canadian production of certain products, and on United States figures for the gallons of water required to produce a unit quantity of each product. It is suggested from comparison with American survey results and figures that Canadian industrial water consumption is 1 to 11/2 billion Imperial gallons per day. Since present information on Canadian usage is meagre and it is not certain that American survey results can be directly applied to Canadian industry, this estimate must await confirmation in future studies.The hydrologic cycle and the principal factors affecting the quantity and quality of water, namely, climate and season, topography, geology, vegetation, and human activities, are discussed and the principal salts dissolved in water which affect industrial use are enumerated.The present survey studies by the Mines Branch on water quality are outlined. Besides chemical analyses of municipal water supplies within a watershed, periodic sampling and analyses of major surface waters for a one-year period is being carried out. The importance of studies on seasonal variation in quality is stressed by comparing the dissolved salts in various river waters with river flow. Figures showing such relationships in the Rideau river and Ottawa river at Ottawa, the Columbia river at Trail, B.C., and the Battle river at Unwin, Sask., are presented. Different rivers show different quality changes with changing flow, and possibly only after long-term studies can the relationships be predicted.Quality studies on water may be as important as studies on many other raw materials. The quantity of the raw material, water, is not inexhaustible nor is the quality indestructible, and more realization of its importance, followed by conservation and intelligent use, is desirable."

Jan 1, 1952

By R. E. Phelan

Introduction The Flin Flon deposit was discovered by Tom Creighton, an experienced prospector and trapper, who in 1914 made his headquarters at The Pas, Manitoba, and still lives there. The discovery was made in the fall of 1914, and Creighton and his associates spent the next summer in investigating the find. In August of 1915 the first claims were located. The property was optioned to Hayden Stone & Company, and in the spring of 1916 they started a diamond-drill campaign. Hayden Stone spent $50,000 on the property and, among other things, completed over 7,500 feet of diamond drilling. The ore not being as high grade as expected, and also being complex in character, Hayden Stone then abandoned their option. In the spring of 1917, Messrs. Earle, Faskin and associates took an option on the property and started an extensive drilling campaign. This campaign accomplished approximately 18,000 feet of drilling and secured for the Faskin interests a 32 per cent interest in the property. In 1920, W. B. Thompson and The Mining Corporation of Canada secured an option, and, while this option was in force, sunk two shafts in the ore-zone and did a considerable amount of drifting and cross-cutting in the ore to study the manner in which it occurred in place, and, by actual channel sampling, to check the grade indicated by the previously accomplished diamond drilling. All of this work had indicated that an ore-body existed on the property containing at least 18,000,000 tons of ore, assaying as follows: gold, 0.074 oz./ton; silver, 1.06 oz./ton; copper, 1.71 per cent; and zinc, ). 45 per cent (1). Complete analyses of composites from the drill holes showed that the ore was very complex in character. It contained the above values in gold, silver, copper, and zinc, as well as large amounts of sulphur and iron, and traces of lead, arsenic, antimony, cobalt, and various other metals. Although the ore was obviously pyritic in character, pyritic smelting, the usual method of treating this class of ore, could not be used to beneficiate the ore with any reasonable expectation of making such a venture a financial success, since coke and coal landed at Flin Flon would be expensive, and siliceous flux was known to be scarce locally and low in grade. The property therefore lay idle until 1925.

Jan 1, 1935

By Mark Weidenbach

OZ Minerals owns and operates the Prominent Hill copper-gold concentrator in South Australia, built in 2008 and commissioned in early 2009. The concentrator operates via semi autogenous grinding in a thirty four foot ThyssenKrupp Polysius mill followed by a twenty four foot Polysius ball mill in closed circuit with hydro cyclones, designed for an ore throughput of eight million tonnes per annum. The main aspects of designing the circuit are discussed along with the issues faced in the early stages of operation. A review of the optimization strategy applied to the milling circuit such as cyclone optimization, advanced process control strategy implementation and reline management to improve availability is then discussed highlighting areas of significant process improvement that have seen the plant exceed nameplate throughputs above nine million tonnes per annum.

Jan 1, 2012

By K. Adham

Both the dry and the wet fluorination systems require hydrogen fluoride (HF) for the process of uranium conversion to uranium hexafluoride (UF6). The dry methods depend on the electrolysis of HF to generate the fluorine (F2) required for the high temperature pyro-fluorination. The wet methods require aqueous HF in water solutions for the low temperature hydro-fluorination (Argonne, 2019). This paper uses the available HF safety guidelines and industry information to discuss the issues of transportation, storage and utilization. Health effects and environmental considerations are reviewed. Safe practices for handling the HF (both as anhydrous and as aqueous) are considered. Proper selection of different materials of construction are discussed, for both the anhydrous and the aqueous HF.

Jan 1, 2020

By Ellie Condolios

Hydraulic hoisting offers a number ~f attractive features over conventional hoisting methods: small shaft space requirements; great flexibility of layout, including pick-up or delivery of the material at points distant from the mine shaft; low investment and operating costs. However, limited practical experience with this type of hoisting dictates that careful design and, frequently, extensive testing be done by competent engineers before large-scale installations are built. This paper covers the following: basic laws and design criteria for hydraulic hoisting installations; a description of a coal hoisting installation which has been in industrial operation since 1960, with a vertical lift of 600 feet and an annual capacity of 500,000 tons of -3 ~-in. coal; and a tentative appraisal of the process, including cost estimates. THE transportation of solids in water flowing through a pipe-line has, for a number of years, been common practice in dredging, public

Jan 1, 1963

By A. A. Bakke

"The Fort Knox gold deposit is hosted within the Fort Knox Pluton, a Cretaceous multiphase granitic body that intrudes the Fairbanks schist. Gold occurs along the margins of stockwork veins and veinlets, quartz-filled shear zones, and along fractures within the granite. The mineralization is generally sulphide-poor and closely associated with trace amounts of bismuth, tellurium and to a lesser extent with molybdenum and tungsten. At present, proven/probable reserve estimates, based on a cutoff grade of 0.39 g/t Au, are 158.3 million tonnes grading 0.83 g/t Au.The Fairbanks schist comprises the bulk of the country rock. The dominant lithologies present include muscovite-quartz schist and micaceous quartzite. Immediately north and south of the main orebody, mixed metamorphic lithologies of the Cleary sequence, a subunit of the Fairbanks schist, have been mapped. Development of local zones of weakness, most likely due to a broad regional warping event, resulted in brittle-ductile deformation and activation of a northwest-southeast shear couple between contrasting lithologies.The Fort Knox Pluton consists of at least three phases based primarily on textural differences. Intrusion of a fine-grained granite was followed by a medium-grained porphyritic granite. The youngest intrusive phase is a coarse-grained, seriate porphyritic granite, the Vogt Stock. The Vogt Stock forms an elongate dome with the axis in the east-west direction. Structures displayed in the overlying units, believed to be the result of doming, include tension fiSSUres and longitudinal fractures.Premineralization fractures, the result of the magmatic doming, provided conduits for initial stockwork quartz vein development and quartz enrichment in shear zones. Weak development of vein-controlled phyl/ic, potassic, albitic, and argillic alteration styles are present. Evidence of a late thermal event resulting in a low-temperature alteration assemblage of calcite + zeolite (stilbite) + chalcedony + clay occupies breccia zones, joint surfaces, and fractures within the granite."

Jan 1, 1995