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By Dorothy Walters

As an increase in the number of producers alters fact ors affecting supply, long-term prospects in traditional markets for many minerals weaken. At the same time, conflicts between national and international objectives undermine existing competitive elements in mineral markets and Canadian costs escalate. Such changes may dramatically alter the environment in which the mining industry operates.

Jan 1, 1979

By Pierre Rocque

The Red Lake Mine is located approximately 600 km northwest of Thunder Bay. This 545 tpd (600 tons/day) underground narrow vein gold operation is set to produce in excess of 14.8 tonnes (475,000 ounces) in 2001 at a cash operating cost below 75 U$/oz. The high-grade nature of this deposit (>55 g/t or >1.6 opt) coupled with its complex geological environment and relatively deep location dictated the choice of a very selective primary mining method, Mechanized Overhand Cut and Fill. In addition to geological challenges, mine design issues such as material handling, ground stability and requirements for yieldable ground support are also discussed in this paper.

Oct 1, 2001

By J. S. Stachulak, K. A. Mackinnon

This paper deals with specifying and evaluating fans for mine ventilation projects. Topics such as fan and equipment design life, operating points, and operating conditions are discussed. Common operating problems, such as vibration, parallel operation, mechanical failure, erosion, corrosion, and deficient fan performance are covered. Apart from identifying the potential operating problems, likely causes and suggested remedies are given. Fan type, fan accessories, and likely system effects and fan testing are discussed. Suggestions on what should be covered when evaluating different fan options and proposals and suggestions on the verification of supplier claims and guarantees, including cost of operation, the evaluation of initial capital cost, estimate on maintenance costs, and likely replacement expenditure over the life of the fans. In addition, fan reliability, operational flexibility, suggested construction details and fan vendor past history and experience are reviewed.

Jan 1, 2004

By A. Jafarnia

Aluminum alloys are frequently grain refined during solidification in order to promote the formation of an equiaxed grain structure in the casting. The application of Ti-based grain refiners and/or Ti containing master alloys for improving mechanical properties may result in formation of Al-Ti based intermetallics. Although the grain refinement produces many desirable qualities in aluminum castings such as improved castability and mechanical properties, the addition of Ti to Al-Si foundry alloys may lead to the formation of some undesirable intermetallic particles such as AlTiSi and cause a number of operational problems such as nozzle blockage due to segregation and agglomeration of aluminide particles within the nozzle. There are several questions to be clarified when minor amount of Ti is added to Al-Si alloys. They include nucleation and growth of AlTiSi particles, their morphologies and orientation relationships with aluminum matrix and the dissolution of these intermetallics during the course of solidification and/or post solidification treatments. The current study was initiated to study the process and possible mechanism of aluminide dissolution and the related phenomena such as segregation and agglomeration. It reports the results found during reheating of laboratory prepared Ti-added A356 alloy at three temperature ranges of below solidus, mushy zone and above liquidus.

Jan 1, 2004

By Brad Wells, Wayne Bull, Wayne Dickinson

"Antiscalants were evaluated for control of calcium carbonate (CaCO3) in gold processing applications. Under severely supersaturated conditions, 100 percent inhibition was achieved with 30 ppm antiscalant. Laboratory and field testing established that an antiscalant could both inhibit scale buildup and remove an estimated 0.5 kg/m2 per annum of pre-existing scale. A program was developed to control CaCO3 at a gold mill experiencing severe scale buildup. Annual accumulation of as much as 3 cm of scale in process piping was reduced to unmeasureable levels when 10 ppm antiscalant was applied. No scale-related upsets in mill operation occurred during a five-month trial period.INTRODUCTION Inorganic mineral scale is a crystalline deposit that forms when dissolved mineral constituents exceed the solubility of the respective mineral phase. Formation of mineral scale adversely affects a wide range of industries and is of particular interest in mining and metals processing. Scale affects numerous stages of metal extraction processes. Restricted flow in piping, nozzles, valves, screens, pumps and other components used to transport mineral slurries, metal concentrates, and tailings as well as scale in millwater and thickener overflow circuits are primary concerns (Alfano & Boffardi, 1994). Heap leaching, comminuation, flotation, vat leaching, carbon adsorption, and heat exchangers as well as oxidation steps used in processing sulfidic ores are among key unit operations that may be adversely affected (Simmons & Gathje, 2003). Antiscalant chemicals are designed to prevent formation and growth of mineral scales such as CaCO3. These chemicals, which include two primary classes – phosphonates and anionic carboxylate polymers and copolymers - are added to the gold processing stream at low parts-per-million (ppm) concentrations to interfere with nucleation and growth of scale forming crystals and to disperse fine particulate material. Application points may be located throughout the gold extraction process. Evaluation of the performance of antiscalants plays a critical role in determining the best product for a specific application. Performance evaluations include laboratory testing, pilot scale studies, in-plant trials, and ongoing performance monitoring during mill operation."

Jan 1, 2014

By K. Nikkhah, N. Dhadli, G. Freeman

Ammoniacal pressure leaching operations have been in commercial use at the Fort Saskatchewan refinery of Sherritt International Corporation since 1954. Recent improvements have significantly increased the capacity of this circuit. The computer modeling of this process has proved to be a valuable tool in facilitating the evaluation of different operating scenarios in an effective manner. Reagent response in the ammonia leach of nickel and cobalt sulphides is examined using the dynamic process simulation capabilities of IDEAS(TM) software. The dynamic simulation enables accurate measurement of the sensitivity of the process to variables such as temperature, feed rate and ammonia concentration as well as compartmental analysis of metals concentration, pulp density, vent gas composition, and the formation of specific complexes. The complexity of the ammonia leach process makes it a logical choice for evaluation by computational analysis. The methodology for dynamic modeling of a pressure leach process is presented.

Jan 1, 2005

This paper details a brief history of the Australian gold industry from the 1980s gold boom to the present day, highlighting an industry characterised by innovation in plant design and junior companies prepared to "have a go", in contrast to the conservatism of many larger mining companies. Design flexibility, the innovation of new processes, the preparedness to exchange "process know how" and technology singularly differentiated the gold industry from other sectors during the 1980s to the present. The introduction of two stage crushing, semi autogenous (SAG) milling, and pebble crushing, mill innovations, carbon in pulp (CIP) and carbon in leach (CIL) and the North Kalgoorlie screen etc were all exciting changes in the industry.

Jan 1, 2011

By T. Mulpeter, G. Deschênes

Sadiola Gold Mine is an open pit operation located in Mali and owned by Anglogold Ashanti Ltd, Iamgold Corporation and the State of Mali. A conventional cyanidation process (cyanidation/CIP) treats 15,000 tpd (of a mixture of oxide and sulphide ores) at an average grade of 3 g/t Au. In 2002, the increasing tonnage of sulphides caused an increase in production costs and a decrease in gold extraction (from 95% to 70-76%). Because of the short retention time of the leach circuit (18 hours) and the refractory nature of the sulphides, gold leaching kinetics are critical. A laboratory investigation was initiated to evaluate actual plant practice and identify a means of improving the gold leaching rate. The study was conducted on a "soft" sulphide gold sample containing 4.96 g/t Au, 0.4 g/t Ag, 2.5% pyrite, 1.2% arsenopyrite, and 0.2% pyrrhotite with a P80 of 74microns. Pre-leaching significantly influenced the gold leaching rate. A short pre-leach (2 hours) performed at pH 8, a DO of 8 ppm, and with 300 g/t lead nitrate added at the start or the end, produced the preferred conditions. Pre-leaching for more than 2 hours was detrimental to gold extraction. The cyanide concentration had to be maintained at 450 ppm NaCN to reach a maximum gold extraction within the retention time of the circuit. A maximum extraction of 81.3% Au was obtained in 20 hours (leach residue at 0.97 g/t Au). A high level of dissolved oxygen in the pre-leach was not of any benefit. Extension of gold leaching beyond 20 hours indicated that all leachable gold had been extracted by that time. Plant modifications were made to allow leaching of oxides and sulphides in separate circuits. Treatment of oxide ores is now performed at a higher rate. Sulphides are processed at a lower throughput, with 300 g/t lead nitrate, to allow a retention time of 22 hours. Combined throughput remains the same, and total gold recovery has increased from 76% to 80% for an additional gold production of 16,000 ounces per year.

Jan 1, 2005

By Patrick R. Stephenson

The Australasian Code for Reporting of Mineral Resources and Ore Reserves (the ?JORC Code?) has been operating successfully for 14 years, and has an ancestry dating back over 30 years. Together with complementary developments in stock exchange listing rules, the Code has brought about substantially improved standards of public reporting by Australasian mining and exploration companies. The Code is regarded as a world leader in its field, and has been used as a basis for the development of resource/reserve reporting standards in other countries. The reasons for its success are varied, foremost amongst them being its adoption in full by the Australian and New Zealand Stock Exchanges, and the ability and willingness of mining industry organisations to bring Competent Persons to account when necessary. The latest revision of the JORC Code was undertaken in 2002/03, based in part on releases of upgraded reporting standards in Canada, United Kingdom/Western Europe and South Africa, and the 2003 edition is expected to be released mid-year. Two of the more significant changes are: the introduction of a requirement for a Competent Person to be responsible for the documentation upon which Exploration Results are reported; and inclusion in the definition of a Competent Person of a reference to ?Recognised Overseas Professional Organisations?, being overseas professional organisations to which Competent Persons may belong for the purpose of preparing documentation for the submission of reports to the Australian Stock Exchange.

May 1, 2003

By T. A. Kirk

"The Linatex Dewatering System is a compact, low capital and maintenance cost matched set of processing equipment suitable for solids recovery, dewatering and desliming sand-like materials in the range 3/8"" to 325 mesh ( 1). Since its introduction to North America in the early 1970s, various elements of the system have been successfully installed in a variety of applic11tions both in Canada and the U.S.A. Examples are chosen from the coal, fine aggregates, iron ore and industrial minerals industries.II. Elements of the Linatex Solids Recovery System(A) The Linatex Separator (See Fig.I)The Linatex Separator, which is the heart of the system, is a specialized type of hydrocyclone designed to give a self regulating rope discharge product. It has the familiar cyclone geometry of cylindrical and conical section, tangential inlet, apex and vortex finder. The apex is enclosed in a unique patented automatic underflow regulator consisting of a collapsible rubber sleeve, and the overflow line is a siphon-leg, with a controlled air bleed valve. The siphon leg is adjusted so as to balance the internal negative pressure acting as a closing force on the underflow regulator against the mass of slurry pressing down on it from the cone section of the Separator. With correct adjustment the underflow regulator will close drip-tight on a water only feed. As solids accumulate in the apex of the cone the weight of solids counterbalances the vacuum and cat1ses the underflow regulator to open and discharge classified material at a controlled density."

Jan 1, 1978

By John Loop, W. A. Gibbins, Donald D. Hogarth

"Introduction Background The Frobisher voyages of 1577 and 1578 were organized by the Cathay Company for the express purpose of finding and mining gold ore. Since publication of the Baffm expedition of Charles Francis Hallill, the location of Kodlunarn or Countess of Warwick Island, the headquarters of Frobisher's third (1578) voyage, and focal point of the largest Arctic voyage of all time, has been known to the world. Through Hall we also know the location of the Countess of Warwick Mine on Kodlunarn Island. However, the exact locations of the other mines are not known. Of the ""ore"" we know little. Pieces of the original ""black stone"", once as large as ""a half-penny loaf' have now disappeared altogether. Specimens collected at random from the repository of shipments in England and from loose rock on Kodlunarn Island were termed, respectively, ""hornblende pyroxenite"" and ""amphibolite"" and from a locale about 200 yards from Kodlunarn as (hornblende) ""pyroxenite""121. However, it is uncertain whether these specimens are representative of Kodlunarn or of the other mines, although Blackadar131 notes that, in the northern trench of Kodlunarn, biotite gneiss contains lenses and bands of amphibolite. The ""gold"" itself is even less well defined. It has long been accepted that gold was virtually absent in Frobisher's ore. The ""gold"" has been termed pyrite, biotite and both biotite and pyrite together. Even t h e word "" marquesset"" , which appears and reappears in contemporary descriptions, is nebulous and is defined as ""a stone participating in the nature of some metal, yet in so small quantity, that the metal cannot be melted from it"" (0.E.D., definition of 1616)."

Jan 1, 1999

By J. Walker, G. E. Kim

Since May of 2000, Mogas Industries, in partnership with F.W. Gartner Thermal Spraying Co. and using the services of Perpetual Technologies, has invested time, energy, and resources towards developing novel ball valves for high-pressure acid-leach (HPAL) service. In addition to developing new valve designs, an aggressive coatings development effort has been undertaken to improve the protective quality of the coatings so as to enhance the performance and extend the life of valves in severe HPAL conditions. In 2001, Mogas Industries qualified and applied a nanostructured titanium oxide (n-TiO2) coating for gold and nickel/cobalt HPAL services. The n-TiO2 coating provided dramatically superior protection against abrasive and erosive wear, fared very well against high-pressure autoclave corrosion testing, and has performed well in HPAL service.

Jan 1, 2004

By J. -F. Blais, M. -O. Simonnot, P. Charbonnier, J. Mocellin, Université de Lorraine INRA, G. Mercier

"Huge amounts of air pollution scrubber sludge have been generated during ferromanganese production using blast furnace. These residues have been historically deposited in ponds near steel making plants. They are very rich in zinc, manganese and lead (5 to 40 %) and also contain aluminum and iron. Considering the market value of these metals, brownfield sites can now be used as secondary resources. These ponds also have to be cleaned up to meet the environmental regulations.We have developed a hydrometallurgical process to recover Zn, Mn and Pb in order to produce valuable compounds of Mn and Zn and recover the final Pb residue by pyrometallurgy. The Zn and Mn compounds need to be pure enough to be economically valuable. Batch laboratory tests were carried out to determine suitable selective leaching conditions. The investigated operating conditions were acid concentration, pulp density and temperature. Optimal conditions to maximize zinc extraction (100 %) and manganese extraction (95.9 %) were found using sulfuric acid and sodium metabisulfide. The final residue contained 14.8 to 23.8 % of Pb. Then, Zn was recovered in the form of ZnO or ZnS by precipitation and Zn metal by electrowinning, while Mn was recovered as MnCO3 with a fairly acceptable concentration of impurities.INTRODUCTIONFerromanganese has been produced by pyrometallurgy in much of Western Europe for centuries. Use of wet scrubber to remove pollutant and dust particles from gas stream was common for most of these operations. Those residues contain high concentration of Zn, Mn and Pb. They have been left to decant in settling ponds installed close to the steel production plants. They now constitute heavily contaminated artificial soils. Those sludges are so contaminated with Zn, Mn and Pb that they can be used for metal production. Currently, no method is available to decontaminate these residues and recover Zn, Mn and Pb. Therefore, an approach considering these brownfield sites as secondary resource is in development. Doing so would achieve two goals, decontaminate the site and produce metals.. (Huot, Faure, Biache, Lorgeoux, Simonnot, & Morel, 2014a; Huot, Simonnot, Marion, Yvon, De Donato, & Morel, 2012; Huot, Simonnot, Watteau, Marion, Yvon, De Donato, & Morel, 2014b)."

Jan 1, 2016

By James B. Templeton

"IntroductionWith the steady rise of the cost of coal and freight, the time is now ripe for an investigation into the feasibility of using the heat pump for heating purposes in fairly remote industrial areas.The gold mines of northern Ontario seemed to be a most likely place for the application of the heat pump.It was decided that the first step in the investigation would be to determine what economic advantage was to be gained by using the heat pump and thereby determining whether a further and more detailed research programme was warranted.If we can use the heat pump with economic advantage, we can reduce our mining costs and make a worthwhile contribution to our national economy by reducing the import of U. S. coal.The investigation was conducted under the auspices of the Nipissing Fellowship and directed by Professor R. E. Barrett of the Department of Mining Engineering, University of Toronto.With the able guidance of Mr. C. S. Gibson, of the Mines Accident Prevention Association of Ontario, the author visited the following mines: Mcintyre-Porcupine, Delnite, Dome, Lake Shore, Wright-Hargreaves, Kirkland Lake, Macassa, and Kerr Adcliso11.In all cases, the management and technical personnel of these mines were most co-operative and helpful in supplying information and ideas.It should be emphasized at the outset that the design and operation of the heat pump itself is by no means complicated or even new. The reason we hear so much about it today is because there have been improvements in compressors, motors, and heat exchangers in the past few years, and because fuel and freight rates have risen to such a point that, in some cases, the heat pump now has an economic advantage over other methods of heating."

Jan 1, 1950

By C. R. Ross

"The purpose of this paper is to review the activities of international organizations concerned with the problem of dust hazards in mines and to indicate the extent of Canadian participation in these activities. The work of the International Labour Office in sponsoring conferences and reports on the appraisal and control of dust hazards and in the development of standard radio-logical classifications is considered in some detail. Also discussed are the role of technical societies, such as the American Conference of Government Industrial Hygienists, in the development of proposed standards for dust exposure and the functions of international committees concerned with particular hazards, such as the U.I.C.C. (Inter-national Union Against Cancer) Committee on Asbestos and Cancer."

Jan 1, 1969

By Bill Shand

"Placer Dome - Campbell Mine is a gold mine located at Balmertown in the Red Lake District of North Western Ontario. During the last 50 years, the mine has produced over ten million ounces of gold.A change in ball mill grinding media was made in August 1998 from 1.5” diameter forged balls to 1.5” diameter, 18% chrome balls. This was done to reduce grinding media consumption and to potentially help flotation performance.A marked ball test done in September-October 1999 showed that, of the alloys tested, 18% chrome was the optimum for the ore at Campbell Mine. The test showed that consumption of chrome balls should be 3 times less than forged balls.In December 1999, the ball size was increased from 1.5” to 2” in an effort to reduce the amount of oversize rock discharging from the ball mill. This change in size was successful.Grinding media consumption for the ball mill decreased 73% from 1.20 kg/tonne before the use of chrome balls to 0.327 kg/tonne after the use of chrome balls. This clearly indicates that, for the ore at Campbell Mine, there is significant savings in grinding media by using chrome.Grinding ball costs were reduced by 59% from $O.88/tonne of ore milled to $0.36/tonne of ore milled representing a saving of $298,000 per year. This also clearly indicates that using chrome balls is a benefit at Campbell Mine.Test work to show that chrome grinding media is beneficial to flotation has been inconclusive so far but is still ongoing.No tests have been done to see if there would be a benefit with an even higher chrome percentage in the grinding media. Test work in this area is also planned for the future"

Jan 1, 2001

By R. Pot

"IntroductionTHE PURPOSE of this paper is to discuss briefly the main logging and testing devices presently at our disposal, to point out some of their limitations, and to suggest possible improvements of the techniques.Some of the more important devices .are those that are used in:(1) Coring(2) Formation testing(3) Electric well logging(4) Radioactive well logging(5) Measuring of bottom hole pressures(6) Sampling of reservoir fluidsThe first four of these procedures are concerned with the well while it is in the process of drilling. The last two are carried out as soon as possible after a well has been brought into production and .at intervals during its life. My remarks will be concerned mostly with certain aspects of formation testing. The reservoir engineer is dependent on the information derived from these operations in order to obtain a clear picture of the conditions in a reservoir and to enable him to assess and forecast its future behaviour.Since any calculation is no better than the data on which it is based, not enough emphasis can be placed on the necessity for the testing and logging equipment to be of the highest quality and for the analysis of the results obtained to be thorough."

Jan 1, 1952

By A. Brown

THIS P APER has been pre-pared as a progress report on Mines Branch investigations into problems of ground stress in certain co al mines of Western Canada. As such, it should be considered as a companion report to the one ( 1) presented to the Mining Society of Nova Scotia in 1956 and which dealt with similar investigations in the coal mines of Eastern Canada. For the past 50 years, dynamic incidents in the form of 'bumps' and 'outbursts' have been occurring in the coal mines of the Inner Foot-hills belt of tl1e Canadian Cordillera. As these phenomena generally become more frequent with in-creased thickness of overburden, a limiting depth of mining of 2,500 feet has been set (2) for estimating recoverable reserves of coal. If such a view were accepted, from a long-term viewpoint very large resources of coking-grade ?coal -in a part of the continent deficient in such coals -would not be available to the nation. The terrain in which these in-6dents take place may be described in geological terms as being dominated by pronounced structure in strata ?consisting of a large proportion of highly indurated rocks. The Geological Survey of Canada has co-operated by carrying out structural studies (3) at the mines, supplemented lithological by stratigraphic observations.

Jan 1, 1958

By W. Standifird

"Cohesive fracture is a mechanical model widely used for modeling quasi-brittle fracture in rocklike materials. This work discusses use of this model to simulate quasi-brittle fractures generated by injection stimulation during the process of cuttings reinjection in West Africa. Cuttings reinjection is an engineering practice used for disposal of drilling waste. During this process, hydraulic fractures are created at the target formation and milled cuttings are injected with fluid. In practice, this process must remain in compliance with environmental regulations and zero-discharge policies. The purpose of this study is to determine the following factors of injection design for a field in West Africa: (1) pumping pressure capacity required to successfully perform the injection and (2) the injection rate for injection performance and the value of fracture width under injection.A simplified three-dimensional (3D) finite element model (FEM) was built. A poroelastic plastic damage model was used for simulation of the cohesive crack prorogation within the target formation. For simplicity, fracture development in both horizontal and vertical directions was simulated separately. In this way, the computational burden for one calculation was reduced to a reasonably low level, without losing accuracy of the model. Loads of the model include fluid injection and gravity, which balances the initial geostress field. Various values of injection rate were used in these calculations to determine the most reasonable value of injection pressure. The capacity of pressure of a pumping device was determined using this optimized value of injection pressure.Results in values of width and length of fractures created by the injection are presented. Injection pressures at bottom-hole (BHP) corresponding to each value of injection rate are also given. Numerical results for fracture generation and propagation in a horizontal direction were visualized. The pumping pressure capacity required to fulfill the cuttings reinjection work was determined based on the numerical results of optimized injection rates and pressure. The fracture width was determined using the given pumping pressure. The length and height of the fractures was determined using pumping pressure along with the required volume of cuttings waste to be disposed of into the formation.This work presents a case study of 3D finite element modeling of hydraulic fracturing generated by cuttings reinjection. The results of the optimized injection rate and pressure provide a best practice and a useful reference for cuttings reinjection analyses in this region."

Jan 1, 2015

By Yoshimasa Funakawa, Kazuhiro Seto, Akio Kobayashi

A new hot rolled high strength steel consisting of ferrite matrix and nanometer¬sized precipitates was developed. The ultra fine precipitates were identified as TiMoC2, and the strengthening by the precipitates was evaluated more than 300MPa in case of TS/800MPa grade steel. Due to the strengthening effect of the ultra fine precipitates, alloy elements for solid solution hardening can be reduced. It is notable that the steel shows very high yield strength (730MPa in case of TS/800MPa) and very high local elongation leading to excellent stretch flange formability at the same time. The mechanical properties of the steel are attractive for chassis parts and structural parts of auto body. The steel has been produced commercially, and applied to the parts successfully.

Jan 1, 2004