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By M. D. Johnson, R. K. Bezys

"The majority of Ontario's limestone and dolostone production comes from a few Paleozoic carbonate units. In eastern and central Ontario, Ordovician rock units, which are the main sources for production, include the Oxford, Gull River, Bobcaygeon, Verulam, and Lindsay Formations. They are predominantly utilized for aggregate and cement manufacturing, with the Bobcaygeon Formation being used as a source of building stone. Along the Niagara Escarpment, the Silurian Lockport, Amabel, and Guelph Formations are sources for the limestone industry. The largest tonnage of rock extracted by the industry comes from these Silurian units, especially the Lockport and Amabel Formations. These units are used primarily for aggregate, although they are also a source for lime. In southwestern Ontario, the Silurian Bertie Formation and Devonian strata, represented by the Bois Blanc Formation, Onondaga Formation, Detroit River Group, and Dundee Formation, contribute to Ontario's production of lime, cement production and crushed stone. The Detroit River Group (Lucas and Amherstburg Formations) is the main source of the lime and cement produced in the province.Northern areas, which may become significant sources for the industry, include Manitoulin Island, the Lake Timiskaming area, and the James Bay Lowland. IntroductionThe Engineering and Terrain Geology Section of the Ontario Geological Survey has undertaken a geological inventory of all active and abandoned limestone and dolostone quarries in Ontario. This geological study, combined with a commercial study of active quarries carried out by the consulting firm of Derry, Michener, Booth and Wahl, will provide an up-to-date report on the industry in the province and will be published by the Aggregate Resources Section of the Ministry of Natural Resources. This report will follow the format and style of D.F. Hewitt's Ontario Department of Mines Industrial Mineral Reports and Circulars (Hewitt, 1960, I964a, 1964b, 1964c; Hewitt and Vos, 1972). Examinations of the quarries were carried out by geologists in the Paleozoic I Mesozoic Geology Subsection of the Engineering and Terrain Geology Section, and include, in addition to the authors, R,R. Wolf, V.A . Mazur, and D.K. Armstrong in the summer of 1986."

Jan 1, 1988

By M. D. Johnson, R. K. Bezys

"The majority of Ontario's limestone and dolostone production comes from a few Paleozoic carbonate units. In eastern and central Ontario, Ordovician rock units, which are the main sources for production, include the Oxford, Gull River, Bobcaygeon, Verulam, and Lindsay Formations. They are predominantly utilized for aggregate and cement manufacturing, with the Bobcaygeon Formation being used as a source of building stone. Along the Niagara Escarpment, the Silurian Lockport, A mabel, and Guelph Formations are sources for the limestone industry. The largest tonnage of rock extracted by the industry comes f rom these Silurian units, especially the Lockport and Amabel Formations. These units are used primarily for aggregate, although they are also a source for lime. In southwestern Ontario, the Silurian Bertie Formation and Devonian strata, represented by the Bois Blanc Formation, Onondaga Formation, Detroit River Group, and Dundee Formation, contribute to Ontario's production of lime, cement production and crushed stone. The Detroit River Group (Lucas and Amherstburg Formations) is the main source of the lime and cement produced in the province.Northern areas, which may become significant sources for the industry, include Manitoulin Island, the Lake Timiskaming area, and the James Bay Lowland. IntroductionThe Engineering and Terrain Geology Section of the Ontario Geological Survey has undertaken a geological inventory of all active and abandoned limestone and dolostone quarries in Ontario. This geological study, combined with a commercial study of active quarries carried out by the consulting firm of Derry, Michener, Booth and Wahl, will provide an up-to-date report on the industry in the province and will be published by the Aggregate Resources Section of the Ministry of Natural Resources. This report will follow the format and style of D.F. Hewitt's Ontario Department of Mines Industrial Mineral Reports and Circulars (Hewitt, 1960, I964a, 1964b, 1964c; Hewitt and Vos, 1972). Examinations of the quarries were carried out by geologists in the Paleozoic I Mesozoic Geology Subsection of the Engineering and Terrain Geology Section, and include, in addition to the authors, R,R. Wolf, V.A . Mazur, and D.K. Armstrong in the summer of 1986."

Jan 1, 1988

By M. Romana

"RMR geomechanics classification is being used all over the World as a useful tool for tunnel predesign and construction. Bieniawski (1989) provided guidelines for tunnel excavation and support, according RMR numerical values; guidelines which are now included in almost all tunnelling books, regulations, and Internet portals. But in the last 25 years tunnelling techniques have changed and some of the guidelines have become obsolete.. The conditions of tunnels for the 1989 guidelines application were: horseshoe shape; 10 m width; vertical stress < 25MPa; construction by drilling and blasting. Actually a substantial number of tunnels are mechanically excavated. The tunnel themselves are now bigger: a span of 14 m. is very common for transportation tunnels. The guidelines included the following concepts: excavation method, rock bolts (20 mm diameter, fully grouted), shotcrete, steel sets. There is an increasing gap between the 1989 guidelines and the practice: in many tunnels different to-the-case excavation and support requirements are established. Bieniawski himself has published a paper (Lowson & Bieniawski, 2013) with different guidelines based in Lowson’s practice, with no explanations and/or justification.In this paper a new set of RMR tunnelling guidelines is proposed taking account of the actual industry conditions, and increased safety regulations. The 5 classes’ limit RMR:values (80,60,40,20) are no more useful actually: Values of RMR (70, 50, 30) are used in practice to define quite different tunnelling techniques. Consequently a 10 subclasses system is proposed. Each subclass covers a span of 10 RMR points. As the number of mechanically excavated tunnels has increased a new correction factor is necessary, according the excavation method.The proposed 2014 RMR guidelines are for tunnels 10 to 14 meters wide, the world practice for new roads/railways tunnels. Many tunnels for water/ services are smaller with smaller support needs. Wider than 16 m caverns are out of the RMR system.It is not possible, nor desirable, to propose only a value for support in each subclass. The new guidelines propose an interval of values for certain types of support. More pessimistic values must be chosen for wider tunnels, tunnels with lower RMR values in each class and cases when a higher safety factor is asked for. More optimist ones are chosen for narrower tunnels, and higher RMR values. Some alternatives are almost complementary, others are contradictory. Sometimes several different techniques are proposed Guidelines are not automatic options. Good engineering judgment must be used when choosing between the different alternatives. Guidelines are not mandatory suggestions."

Jan 1, 2015

By Balmer Neilly

To one with so little experience in matters pertaining to currency, international finance, and foreign trade, this is surely an ambitions venture on my part. However, this is a subject of prime importance to all seriously minded Canadians and, if we are to obtain any clear understanding of the factors involved, we must study the facts and debate such points as may remain at issue. During the last few years, the world&apos; s better known economists have described the gold standard in all its ramifications and in such detail as to leave many of us even more confused than before. If we, then, are to acquire any real conception of its meaning and use, I think we must reduce it to its fundamentals and start from there. To my way of thinking, gold in ? trade and commerce is the symbol of honesty. When you seek to discharge a debt by tendering paper you hand the recipient an I.O.U. which may or may not be good, for the purchase of goods or services to the extent of its face value. When, however, you discharge a debt by the payment of gold, it constitutes a complete and final discharge. There are no reservations - no ifs and ands - and the transaction is definitely closed to the satisfaction of all concerned. Gold, then, is evidence of accumulated and transferable wealth that is immediately acceptable in practically every part of the world. However, there is not nearly enough gold to meet the demands of world trade, and. many years ago this deficiency gave rise to what we now describe as our banking system.

Jan 1, 1949

By Phil Keele

"Manalta Coal Ltd. 's Vesta Mine will supply Alberta Power Limited's 740 MW Battle River Generating Station with 1 128 000 tonnes of sub-bituminous ""C"" coal in 1983. Mana/ta Coal Ltd. and Alberta Power Limited are in their seventh year of a 31-year coal supply agreement. With the exception of localized topographic highs where three coal seams are mined, the Vesta Mine is primarily a single-seam mining operation. Vesta's comprehensive programs of mine planning, preventative maintenance, reclamation, and employee relations make it an efficient and a well run operation. Introduction The Vesta Mine, located in east-central Alberta approximately 300 km northeast of Calgary, supplies sub-bituminous ""C"" coal to Alberta Power Limited's 740 MW Battle River Generating Station. The coal reserves and principal stripping equipment are owned by Alberta Power Limited. Manalta Coal Ltd. owns and operates the additional mining equipment and support facilities. Coal production is from a single pit, 3.5 km in length. Both single and multi-seam operations are encountered in the active pit. In 1983, production is anticipated to increase to I 128 000 tonnes from 906 000 tonnes in 1982. The additional tonnage will be achieved by operating 24 hours per day, 5 days per week. The following sections briefly highlight historical, geological and mining/reclamation aspects of the Vesta Mine. Figure I illustrates the location of the Vesta Mine in relation to the cities of Calgary and Edmonton. History Coal mining for domestic use began near the turn of the century in the Vesta Mine area. Initially, small underground room-and-pillar operations were dominant. As equipment technology advanced, surface strip mining replaced the underground methods."

Jan 1, 1985

By J. A. Bossert

"In 1957, the Department of Mines and Technical Surveys (now Energy, Mines and Resources Canada) issued their first certificate for a fire-resistant conveyor belt. The testing procedure used was a combination of those used in the U.S.A. and the U.K. Subsequently, certification was granted to fire resistant electric cables (1974), fire-resistant mine duct material (1976) and fire-resistant hydraulic fluids (1978).Until recently, the testing procedures were copied from either the U.S. or the U.K. However, since the founding of the new Canadian Standards Association (CSA) Steering Committee for Electrical/Mechanical Mine Safety in 1981, these requirements have come under the close scrutiny of new CSA technical committees who will attempt to adopt or change the existing procedures to meet Canadian needs. This paper outlines the existing test requirements and attempts to predict how they will appear after ""Canadianization"" by the CSA committees.IntroductionFires in underground mines have always been considered more serious than in other locations because of the confined space and limited atmosphere. A fire can make escape difficult or impossible if it is blocking all of the routes to the surface. Also, the products of combustion from an underground fire can asphyxiate anyone not having self-contained breathing apparatus.In an underground coal mine, the consequences of a fire can be even more serious because of the presence of methane and coal dust in the atmosphere (which can explode) and because the coal itself is combustible.For these reasons, the inspection authorities having jurisdiction over underground mine s in Canada are quite concerned about the flammability of any materials that are used in quantity in the underground environmentAs early as 1957, the Canadian Explosive Atmospheres Laboratory (CEAL) was asked to certify conveyor belting as fire-resistant. This is because many miles of this material are used in underground mines in Canada and, as it generally travels through the mine, it is a perfect vehicle for spreading a fire."

Jan 1, 1982

By J. D. Galloway

The mining industry of British Columbia continues to grow steadily in importance. The gross value of the production in 1925, sixty-two and a half million dollars, was a record, and ali indications point to the 1926 output registering a still higher figure. In an industry such as mining, where production means the depletion of known ore reserves, the discovery and development of new &apos;ore-deposits is of the utmost importance. To maintain and increase production, steady development is essential. In this respect, the record of the last three years in British Columbia mining is most satisfactory, as in this period more real development has been carried on than in any similar period in the history of mining in the Province. Prospecting, or the search for new ore-bodies, has also been fairly active, but comparatively few important new discoveries have been reported in the past few years. The mineral output of British Columbia consists of Iode minerals, coat and coke, and building materials. In 1925 the value of the output of these three classes of products was, respectively, about 46, 13, and 3 million dollars. The industry as a whole embraces the mining of these materials, and the treatment and manufacturing processes involved in preparing the various products for the market.

Jan 1, 1926

By M. Fall

The progressive depletion of ore available at shallow depths in several underground mines around the world means that underground mining operations would increasingly be carried out at greater depths and therefore at higher temperatures. However, our understanding of the effect of hot temperatures on the response (mechanical, economical, environmental) of cemented paste backfill (CPB) is still limited. Hence, an extensive laboratory investigation was conducted to study the performance of young and aged CPB, in response to deep mine temperatures. Several CPB samples with different compositions, cured at different temperatures (20 to 50°C) and different times (7 to 160 days) were tested regarding their mechanical properties, economical performance (binder consumption) and microstructural properties. The results show that hot temperatures significantly affect the performance properties of CPB at young and advanced ages. An increase in the curing temperature leads to a considerable improvement of the rate of gain of CPB strength and also to a significant increase of the strength of CPBs studied. CBP samples cured at hot temperatures show lower binder consumption and finer pore structure. Results of this study could serve as background information for the development of optimal mine backfill design procedures.

May 1, 2007

By Jiahao Xu, Namsoo P. Kim, Guikuan Yue

Iron (ferrous ions and ferric ions) plays an important role in the heap leaching of copper sulfide minerals and copper electrowinning. In our previous study, a novel oxidation-reduction potential (ORP) equation only based on the variables of temperature and nominal ferric/ferrous ratio was developed to predict the redox potential of the quaternary H2SO4-Fe2(SO4)3-FeSO4-H2O system, and its applicability was also extended to more complex acidic iron sulfate solutions, especially those generated during the acidic leaching and bioleaching of Printed Circuit Boards (PCBs) to recover copper. In this work, the broader range of applicability of this equation to other complicated acidic iron solutions containing copper ions has been extended and determined. Specifically, synthetic iron-containing solutions with copper ions according to the conditions of industrial electrolyte during copper electrowinning and heap leaching have been used to measure the ORP and test the developed equation. It seems that this equation can still be employed to predict the redox potential of the Fe3+/Fe2+ couple for the simulated solutions under conditions related to copper electrowinning and pregnant leaching solution generated during heap leaching over a wide range of solution concentration, nominal Fe3+/Fe2+ ratio and temperature. It has shown that the prediction and measurement of redox potential is highly useful to estimate and understand the iron chemistry of industrial leaching and electrowinning processes. INTRODUCTION It is well-known that iron (ferric or ferrous) ions are widely involved in the hydrometallurgical production of non-ferrous metals such as Cu, Au and Zn, mainly in the form of acidic iron sulfate solutions. As far as Cu is concerned, in a typical leaching-solvent extraction-electrowinning process, ferric ion plays a central role in the heap leaching process and is reduced to ferrous ions in the pregnant leaching solution. Ferric ion is the most important surrogate oxidant and the dissolved ferric/ferrous couple plays an important catalytic role in accelerating the leaching rate with oxygen as an oxidant (Peters et al., 1986; Schlesinger, King, Sole, & Davenport, 2011). In addition, during the traditional electro-winning process, oxygen is evolved at the anode, and copper is reduced at the cathode. A common idea is that iron in the electrolyte in copper electrowinning cell (with total iron of 1–4.4 g/L) plays an important role in reducing the current efficiency. According to the published results (Winand et al., 1975; Dew et al., 1985; Moats et al., 2009; Khouraibchia et al., 2010), thecurrent efficiency decreases linearly with increasing ferric ion concentration and the energy consumption increase was mainly caused by the decrease in current efficiency.

Jan 1, 2019

By Esau Arinaitwe

The most extensively used methods and approaches for characterizing and selecting frothers for plant application are based on measurements in clean water in the absence of solids and without consideration of physicochemical factors that are known to influence the properties and behavior of practical flotation froths, and hence metallurgical performance. These factors include aquatic chemistry, collectors, modifiers, particle shape and size, and pH. Understanding interactions between these factors and the role and relevance that they play in characterizing frothers and froth zone properties will greatly aid in the frother selection and evaluation process. Such an understanding will also greatly enhance the ability to create frother solutions that are sufficiently robust to plant variability (such as mineralogical, comminution, operational, physical and chemical). This paper reports results of a “systems approach” study designed to probe ways in which physicochemical factors a) influence frothing and bubble size in 2- and 3-phase systems, and b) confound correlation of fundamental measurements with flotation outcome. The concepts and insights gleaned from fundamental frother studies, together with empirical laboratory flotation tests and a thorough understanding of plant needs and challenges were used to develop and implement customized frother formulation at a Cu-Mo flotation plant. Plant metallurgical data and qualitative assessment of froth zone properties showed that a frother formulation developed using the approach described here provided marked improvements in froth characteristics (mineralization, mobility, stability, persistence). These improvements resulted in better circuit control and significant performance advantages, such as improved coarse particle recovery, without detrimental downstream effects. INTRODUCTION Successful recovery of value minerals of sufficient grade via the flotation process requires selective manipulation of the value minerals to render them hydrophobic using collectors and modifiers. The hydrophobized minerals then attach to air bubbles and the mineral-bubble aggregates are selectively transported through the froth zone into the launder. Frothers play a critical role in froth formation and more importantly in achieving and maintaining desirable froth characteristics (for example, stability, mobility, persistence) that are essential in facilitating the selective transport and recovery of value minerals. Fundamentally, frothers contribute to the transient stability of thin liquid films and so aid in reducing bubble coalescence rates in the pulp and froth zones, thus maintaining the small bubbles required for efficient bubble-particle attachment. Invariably, the action of frothers at the liquid/gas interface in the pulp and froth zones impacts bubble stability, water and solids transport to the froth, which in turn impacts froth mobility, froth carrying capacity, and the concentrate grade. Consequently, selection and evaluation of frothers for flotation plants requires careful consideration of the frother type, though the choice is limited to only two main classes of compounds in terms of fundamental chemistry (short chain alcohols and polyglycols). Even with the selection of what is thought to be the best frother for a given application, practical knowledge of the froth zone and experience in controlling its properties is essential for maximizing metallurgical performance.

Jan 1, 2019

By Y. -B. Kang

New databases are being developed to provide the capability to evaluate the suitability of present and potential new Mg alloys for automotive applications through cost-effective calculations. An extensive and complete thermodynamic database is being prepared for Mg alloys formed from among 25 present and potential alloying elements. The database is being developed by critical evaluation, modeling and optimization of available phase equilibrium and thermodynamic data. It contains model parameters giving the thermodynamic properties as functions of temperature and composition. Using the FactSage thermodynamic software, users can access the database to calculate the amounts and compositions of all phases at equilibrium at any temperature and composition or to calculate any phase diagram section in multicomponent alloys, to follow the course of equilibrium or non-equilibrium cooling, to calculate corresponding heat effects, etc. A database of densities and lattice parameters of Mg alloys and intermetallics (as functions of temperature and composition) is also being developed in order to permit the calculation of volume changes during cooling and phase transformations, c/a ratios of the hcp phase, etc.

Jan 1, 2006

By W. Haibei, Lei. Z., Z. Bangsheng, W. Yufang, J. Kaixi

In 2007 output of zinc was more than 3.71 million tons in China. Some new projects have finished FS and several new zinc plants are building now. In recent ten years it happened great changes in zinc industry. For zinc concentrates one pressure leaching plant was built with capacity 10,000t/a and at least four companies are carrying out FS or engineering design now. Direct atmospheric leaching will put into used in China in 2008 with capacity 100,000t/a. It is estimated that until 2010 the output of direct leaching will be 400,000t/a.

Jan 1, 2008

By R. Liu

As Building Information Modeling (BIM) becomes widely adopted by the construction industry, it holds undeveloped possibilities for supporting Facility Management (FM). Some FM information systems on the market claim to address the needs for FM requirement. However, the question of whether the functionalities provided by the current BIM-based FM software companies are those actually required by the FM Professionals still need to be answered. The data is required by FM professionals in the operation and maintenance phases of facilities and type of maintainability problems that frequently occur, which can be solved early in design phase, have not yet been addressed. The aim of this paper is to clarify the frequently occurring maintainability problems and to investigate the potential areas that can use BIM technology to solve the maintenance problems in early the design phase. A survey was conducted to collect perspectives from the industry practitioners for the maintenance problems and their frequency. The survey results indicated that maintainability considerations should be taken into consideration during the facility design phase. The results also address the perceived areas by practitioners that need maintainability consideration in design phase.

Aug 1, 2013

By Janne Karonen, Stephen Hughes, Mikael Jåfs, Jan Stål, Hannu Johto

End-of-life electrical and electronic scrap material attracts attention as a good opportunity for new value creation through efficient metal and energy recovery of such materials. On the other hand, the treatment of such wastes becomes important to avoid problems for society and environment. Treatment of such secondary raw materials faces multiple challenges due to their increasing complexity and evolving nature. Processing of these complex scrap materials together with recovery of a wide range of valuable metals with a combination of pyrometallurgy and hydrometallurgy using Outotec technology is discussed in this paper. One key consideration is environmental performance which needs attention when processing such complex secondary E-waste materials. Outotec has successful experience with commercial projects in the countries at the forefront of environmental and operational standards. INTRODUCTION Increasing attention has been drawn to the responsible processing of end of life Waste Electrical and Electronic Equipment (WEEE) as part of metals recycling, especially copper. It has been estimated that the amount of WEEE globally in 2016 was around the level of 46 Mtpa (Balde et al., 2017), representing a major disposal challenge but at the same time huge opportunity for resource recovery. The potential for increasing the recovery is high, because the official recycling rate of WEEE is in 2016 only 20% (Balde et al., 2017) and at the same time the estimated increase of the WEEE amount is between 3 and 5% per annum in the EU (Eurostat, 2019).

Jan 1, 2019

By A. C. Bonnier

"INTRODUCTIONI have been asked to make available our method of determining the ""Live Inventory"" within a gravity type thickener. The ""Live Inventory"" being that tonnage compatible with the optimum underflow density that satisfies the process requirements.One prerequisite of the calculations is the proper determination of the final pumpable underflow density. A further requirement is that, prior to shutdown, the thickener has been operated properly, particularly that it has not been operated for storage capacity.Until recently I had few chances to check the method. However, I was most fortunate to have had a recent opportunity covering several months on a 300 ft diameter thickener at a plant in the U.S.A., wherein the method was tested and verified many times. The method proved accurate in that our calculated tonnage checked with the actual dried physical inventory of the drying facility.At the precise moment that the feed to the thickener was shut down, a per cent solid determination was made at the critical place and the tonnage in ""Live Inventory"" determined. Let us say that at the moment the thickener U&apos; Flow solids was 20%. The thickener then was allowed to cperate until the U&apos; Flow solids dropped below 20%, at which time the thickener was deemed to be relieved. Anything much less than 20% was not suitable to the subsequent centrifuge operation.Most large metallurgical thickeners have a configuration of three slopes at the thickener ""bed"". These slopes are dictated by the raking blades and are shown on the manufacturers&apos; erection drawings. The first slope is from the outer periphery and generally takes up a distance of about 60% of the radius, the second slope generally taking up the remaining 40%. Within this 40% area, there is usually another slope taken up by the cone on ""B"" type thickeners or an actual steeper inner slope on ""C"" type thickeners."

Jan 1, 1989

By G. A. Gillett, C. F. Bonney

"The Davy McKee combined mixer-settler (CMS), is a liquid-liquid contactor, which has been commercially applied to the recovery of uranium from dilute sulphuric acid-bearing leach liquors. CMS differs from most other solvent extraction systems in that the mixing and separation of the phases is carried out in the same vessel.IntroductionTypical solvent extraction plants for the recovery of uranium operate at organic to aqueous feed flow ratios of 1 : 2 to 1 : 30. Because it is beneficial to mix the organic and aqueous phases at an organic/aqueous (O / A) ratio of between I : 2 and 2 : I there is incompatibility between the over-all and operating O /A ratios.Conventional mixer-settler designs require an external recycle of the minority flow which results in the possibility of over-mixing, increased settling requirements and entrainment losses. Other workers have approached this problem in terms o f enhanced sett ling and this has been partly successful.Davy McKee&apos;s approach involved a radical rethink of the principles of liquid-liquid contact and separation.Description of CMSThe CMS has the important advance that the required mixing O/A ratio can be achieved without external recycle and is not affected by the O /A ratio of the feeds. Three zones co-exist within the CMS unit-a central mixing zone and upper and lower separation zones. A pump impeller on a draught tube is installed within the mixing zone and baffles are installed above and below the mixing zone. Conventional mixer- settlers have several undesirable features which ca n largely be eliminated using the CMS system:"

Jan 1, 1983

By S. C. Livanou, S. P. Tampouris, E. N. Zevgolis

In ferronickel (Fe-Ni) production from oxidized nickeliferous ores, mechanical losses of ferronickel in the slag are reduced by magnetic separation. Slag from the electric furnaces (E/Fs) contains 0.16% Ni. Its magnetic separation gave a pre-concentrate with 0.76% Ni, weighing approximately 6.5% of the feed. Nickel recovery was 29.7%. This pre-concentrate was then treated in a second (concentration) plant. Concentration treatment involves screening, crushing and magnetic separation. A pre-concentrate with 0.76% Ni gave a magnetic concentrate with 2.58% Ni and a non¬magnetic part with 0.35% Ni. Smelting of the non-magnetic part without the addition of a reduction agent in a laboratory electric arc furnace, gave a ferronickel alloy with approximately 20% Ni and a slag with 0.16% Ni.

Jan 1, 2005

By A. J. Hyett

Due to the ongoing revolution in electronics and communications more cost-effective geotechnical instruments can be manufactured using digital technology. This new generation of digital instruments have embedded microcontrollers that provide highly accurate and reliable measurement of geotechnical behaviour in real world units that can be immediately interpreted. Digital measurements can be transmitted across existing mine-wide wireless communication networks, interfaced directly with infra-red enabled PDA?s or PC?s, and parsed to memory by low-cost data-loggers.

Apr 1, 2005

By J. A. MacLellan

"CONSTRUCI'ION OF SHERRITT'S CONCENTRATORSSherritt Gordon is operating two mills north of the 56th parallel, and is presently engaged in building a third. The author was closely involved in the design and construction of all three of these concentrators.The Lynn mill is the oldest of these three concentrators-it is a 4,000 ton per day nickel-copper plant built in 1953. The Fox mill is a 3,000 ton per day copper-zinc concentrator built in 1970. The Ruttan mill will be a 10,000 ton per day copper-zinc plant scheduled to go on line in July 1973.LYNN MILL The Lynn mill including the crushing, concentrating, drying and load out plant is about 69,700 square feet or 17.4 square feet per ton per day. '!his plant was originally built in 1927 at Sherridon, 150 miles south of Lynn Lake, as a 2,000 ton per day copper-zinc plant. In 1952 the plant was moved by tractor train to Lynn Lake. The whole plant was re-oriented within the original perimeter walls as a 2,000 ton per day nickel-copper plant. This plant was expanded to 4,000 tons per day by the addition of t1-Jo rod mills and a 5-1/2 short head crusher in 1959.The Sherridon mill processed its last ore in Sherridon in September 1951 and the first load of nickel concentrate was loaded at Lynn Lake on November 9, 1953 when the railroad arrived at Lynn Lake.The site for the Lynn Lake mill was cleared of overburden in the summer of 1952 and foundations for structural steel and SO!l8 equipment foundations were poured the late summer and fall of 1952 • Steel was erected from January to June 1953. Most of the equipment came in from January to March of 1953 by tractor sleighs. Sane sleighs upset but no equipment was lest through the ice."

Jan 1, 1972

By S. E. Malouf, W. Thorpe

"The Chibougamau Explorers property comprises 35 claims or 1,726 acres in La Dauversiere and Rohault Townships along the west shore of Norhart Lake. The property is serviced by a twelve-mile all-weather high-way leaving the main St. Felicien-Chibougamau highway at mileage 121. This road junction will be a railway siding on the C.N.R. St. Felicien-Chibougamau branch line in early 1957. The property lies 30 miles due south from the town of Chibougamau. The mine-sponsored Chibougamau Explorers town has a population of 250 with 28 residences and a well equipped recreation centre.The original showing was found by Rider Storn, a prospector financed by Val d'Or interests during the 1950 field season. This showing did not stand up to detailed prospecting but it did lead to the discovery of the main zone by A. Oakley during the following winter.The company was incorporated in I 950 under the presidency of E. Ayrhart. Financing following the initial drilling involved an increase of capitalization from 3 to 5 million shares and the advent of financing and management control by Anacon Lead Mines Limited.Exploration and development to Jan. I, 1956, has included 42,331 feet of surface diamond drilling; 31,363 feet of underground drilling; a 3-compartment shaft to 1,245 feet, with 8 levels at 150-foot intervals; and I 1,054 feet of drifts, crosscuts, and raises. Ore reserves to the 900-foot level, proven and partly developed, total 546,725 tons averaging 0·30 ounces gold and 0·93 per cent copper. A mill with capacity of 500 to 750 tons will be installed by January 1956.GeologyThe Chibougamau Explorers property lies along the belt of Keewatin volcanics striking through Bachelor Lake, Opawica Lake, Doda Lake, Coapatina, Norhart Lake, and Rohault Lake, where it is in close proximity to the paragneisses of the Grenville series. The boundary of the paragneisses, a gradational contact, lies within a mile of the Chibougamau Explorers shaft collar."

Jan 1, 1949