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By G. Dubé, A. Leclerc, P. Quinn, G. E. Agar, J. Y. Clouthiér, J. D. McLaughlin

"Gold dissolution by cyanide requires the presence of oxygen which is usually supplied by sparging compressed air into the gold containing slurry. For those ores that contain certain obnoxious substances that consume oxygen, maintaining the required minimum level of dissolved oxygen can be troublesome. One of the most economical solutions to the problem of low dissolved oxygen, especially in plants that have air compressors installed, is to enhance the rate of oxygen mass transfer.The oxygen mass transfer rate was measured in a two phase system using two different sparger arrangements, and with addition of a frother that is known to reduce the bubble size produced by the sparger. The common sparger system was shown to be inefficient compared to a readily available but under utilized method of gas dispersion which introduces air directly below the reactor turbine. Transfer of this technology to an operating plant confirmed the beneficial effect of the improved sparger system. The addition of the frother did decrease the bubble size, but it also reduced the oxygen mass transfer rate."

Jan 1, 1993

By H. W. Wevers

This paper is the result of an intensive literature search and practical study of the problems experienced by a mining company with the frame cracking of their large-tonnage haulage trucks. It explains the advantages of particular HSLA steels for applications in the welded structures of such equipment. Examples of existing welds in truck frames are analyzed. Modern fatigue models and linear elastic fracture mechanics techniques are explained.

Jan 1, 1978

By John Galbraith, Dwayne D. Tannant, Chris C. Langille

"Development of underground openings in a deep mining environment requires a support system that is able to absorb energy as a result of dynamic loading due to rockbursting and blasting and static loading due to convergence as the development face advances. The support system must be resistant to corrosion and be effective over the life of the excavation, upward of ten years, yet simple and cost effective to install. Over the past two years, research has been conducted at INCO’s Creighton Mine to try and identify a one-pass grouted support system that will meet these needs.The main problem faced, with simply using grouted rebar at depth, is the effect of tunnel convergence on the stiff grouted bolts. Typically, if fully grouted, stiff rebar are installed to the face of an advancing development heading, the amount of convergence that occurs can result in failure of the bolts at the face plates used to attach the mine screen to the back. An initial support is required to enable crews to continue the bolting cycle in the immediate term, yet allow for this convergence over the longer term as the drift advances. The ideal support system will allow both to occur, giving effective immediate support while providing long-term effectiveness in allowing convergence to occur while maintaining the capacity of the bolt.This paper will investigate the expected convergence in deep development headings at +2200 m (+7200 ft) through the use of direct measurements using both flex rod extensometers grouted into the back of a development heading and five-point tape extensometer stations. Measured results will be compared with simple2-D numerical analysis to evaluate the anticipated convergence expected to be absorbed by the bolting system. The required convergence will then be compared with load deformation response of several support configurations."

Jan 1, 1996

By Janice Zinck

?Past? Images of Mining ?Historic practices have been poor ?Mining still widely perceived as environmental ?spoiler? ?Public only hears the bad news stories. Lessons Learned from the Past ?Sustainability matters ?Recognition of social and environmental responsibilities ?Recognition of importance of public concerns and perceptions ?Community engagement

May 1, 2009

By E. Gaucher, M. St-Amant

"Among the electromagnetic surveys performed by SOQUEM in the last three years, a certain number of the more instructive cases have been chosen to illustrate the theory of electromagnetism by field examples of: (a) The depth penetration of the TURAM as compared to the SLINGRAM (Ronka) method. (b) The limitations of the TURAM as compared to the SLINGRAM method when a conductor dips the wrong way, or when it is small in size. (c) The expression of a shallow-dipping conductor in a SLINGRAM survey. (d) The effect on the SLINGRAM survey of deep ditches or reef structures.(e) A comparison between the CRONE and the SLING-RAM method in the Abitibi clay belt, by means of field and model studies, indicating a usually better signal-to-noise ratio for the SLINGRAM method. From the above and from other experiments, different electromagnetic methods are now being used by SOQUEM, depending on field conditions."

Jan 1, 1970

By Dave N. K., T. P. Lim

"A fast, reliable and accurate method for radium-226 determination in environmental water samples has been devised, using an alpha spectroscopic technique. The correlation between barium-133 and radium-226 in the barium-radium sulphate precipitation mechanism was studied and in the limited experimental recovery range, the coefficient of correlation was r = 0.986. A self-absorption study for various barium carrier concentrations was also undertaken to obtain the least broadening of alpha energy line widths. An optimum value of 0.3 mg barium carrier was obtained for chemical recovery in the range of 85%.IntroductionWith the increase in uranium mining activities, the migration and spread of radioactivity via various environmental pathways is of great concern. Because of its inherent biological hazard and relatively long half-life, (approximately 1620 years), raidum-226 is frequently monitored as a measure of radioactive contamination of the environment. It is, therefore, necessary to modify existing methods for rapid determination of radium-226 in environmental samples for quick corrective measures in the event of seepage, dam leakage or discharge violations."

Jan 1, 1981

By P. Keller, T. E. Lister, G. G. Clark, L. A. Diaz

As electronic technology continues to evolve there is a growing need to develop processes which recover valuable material from antiquated technology. This need follows from the environmental challenges associated with the recovery of raw materials and fast growing generation of electronic waste. Although present in small quantities in electronic devices, the availability of raw materials such as rare earths and precious metals becomes critical for the production of high tech electronic devices and the development of green technologies (i.e. wind turbines, electric motors, and solar panels). Therefore, the proper recycling and processing of electronic waste presents an opportunity to stabilize the market of critical materials, providing a proper disposal and treatment of a hazardous waste stream. This paper describes the development and techno-economic assessment of a comprehensive process for the recovery of value and critical materials from electronic waste. This hydrometallurgical scheme aims to selectively recover several value streams (base metals, precious metals, and rare earths) present in electronic waste. The economic feasibility for the recovery of rare earths from electronic waste is mostly driven by the efficient recovery of precious metals, such as Au and Pd (ca. 80 % of the total recoverable value). Rare earth elements contained in magnets (speakers, vibrators, and hard disk storage) can be recovered as a mixture of rare earth oxides which can later be reduced to the production of new magnets.

Jan 1, 2016

By Pura Alfonso, Sarbast Hamid, Hernan Anticoi, Eduard Guasch, Josep Oliva

"Av. Bases de Manresa 61-63, Manresa (08242) Barcelona, SpainTantalum is a strategic metal and an improvement of the mineral processing is an important issue. The main objective of this work is to optimize the grinding technologies for tantalum ores with high pressure grinding rolls. The selected ore for this study was an altered leucogranite from the Penouta Open Pit Mine (NW Spain). In the present work mono-size experiments have been carried out using grinding rolls with controlled pressure. The particle size distribution has been monitored in the input and output of the high pressure grinding rolls for each experiment. The cylinder pressure that is transmitted to the particles has been determined. New population balance models are presented for high pressure grinding rolls with parameter adjust for tantalum ore. The obtained model uses the physical description of particles under the comminution action of the grinding rolls. The obtained results are in agreement with other models and the errors in the adjustment are low. The selection function proposed for this model describes adequately the breakage probability of the particles inside the high pressure grinding rolls. The presented model can be a good alternative for simulating a high pressure grinding roll process. INTRODUCTIONTechnology for grinding have been improved for many years, introducing new variables and parameters involving energy consumption, mechanical stress analysis of the compression particles or pressure application for optimizing the comminution (Morrell et al, 1997). High pressure grinding rolls is a modern technology that is proven to reduce the operating costs in full scale plants when compared with other milling technologies. Its benefits on energy saving and simplicity in the process have been studied and applied, first in the cement clinker industry (Abouzeid & Fuerstenau, 2009) and after in mining activities, especially in metallic ore deposits (Austin et al, 1991; Guevara & Menacho, 1992; Morrel et al, 1997; Torres & Casali 2009; Numbi & Xia, 2015). Many author structures of the High Pressure Grinding Rolls modelling in three main branches; (a) throughput modelling, (b) Power and energy model and (c) particle size distribution modelling (Austin et al, 1991; Guevara & Menacho, 1992; Austin & Trubelja, 1994; Morrel et al, 1997; Torres & Casali, 2009)."

Jan 1, 2016

By D. M. Maijer, S. L. Cockcroft, A. B. Phillion, P. Fan, C. Reilly, H. Khadivinassab

A combined experimental / numerical approach is proposed to investigate the bulk transfer of solute due to liquid metal feeding during shape casting of aluminum alloy A356 (Al-7Si-0.3Mg). A dumbbell-shaped experimental casting geometry has been developed, which promotes solute redistribution due to liquid metal feeding. The redistribution of solute in trial castings is evaluated based on the area fraction of eutectic phases. In the numerical model, silicon species segregation during solidification are calculated assuming the Scheil approximation, and are coupled with macro-scale solute transport due to Darcy flow in the mushy zone and feeding flow. The model has been implemented within the commercial CFD software, FLUENT, which simultaneously solves the thermal, fluid flow fields and species segregation on the macro-scale. The experimental and numerical results are compared and contrasted to examine the effects of liquid metal feeding in this casting.

Jan 1, 2014

By Charles Graham

It is the general belief that the coal deposits on Vancouver Island are extremely large, and easily available. Indeed, they are frequently described by prominent public men and by writers in the press as "illimitable" and "inexhaustible." It is well that the facts that have been established as a result of seventy years of surface prospecting, underground operations and extensive diamond-drilling in this coalfield should be disclosed. HISTORY The presence of coal on the coast of British Columbia was first made known by Dr. W. F. Tolmie in 183 5. This coal was brought to him by Indians from the north-east coast of Vancouver Island, probably from Suquash. In 1850 the existence of coal at Nanaimo was announced by Mr. ]. W. MacKay. Development was started in 1852, and coal was shipped before the close of 185 3. The first operations were carried on by the Hudson's Bay Company, who operated the mines until 1861, when they sold them to the Vancouver Coal Mining and Land Company. Practically all of the operations in the immediate vicinity of Nanaimo have been carried on by this Company and its successors. In 1869, Mr. Robert Dunsmuir discovered coal about five miles north-west of Nanaimo, at Wellington. The Welling-ton Colliery Company was organized, and began to produce coal from the Wellington mines in 1871, the coal being shipped from Departure bay. This colliery was a large producer for several years, but was finally closed in 1900.

Jan 1, 1924

By F. Khomamizadeh

In this study the effect of solidification rate, T6 and T7 heat treatments on thermal fatigue resistance of A319 aluminum was investigated. Increasing of the solidification rate improved the thermal fatigue resistance of the alloy by refinement of the microstructure. The most sensible areas for thermal fatigue crack growth were the eutectic zones, T6 and T7 heat treatments improved the thermal fatigue resistance of the alloy by enhancing of the matrix resistance against the crack propagation. The slight reduction of the thermal fatigue resistance after T7 heat treatment is attributed to coarsening of the precipitates which reduces the matrix resistance.

Jan 1, 2005

By James E. Fisher, Roger Cotton

"The legal background f or environmental issues, and the growing emphasis both from government and private concerns of corporate and management liability for environmental problems provides one of the driving forces behind the growing concern with environmental law for the future. One prime objective must be the identification and minimization of potential liability, both for the corporation and its officers, directors and employees.This paper will identify the basis for liability of individuals and corporations for environmental matters, focussing on current legal requirements, and the appropriate legal response to events of such potential liability. It will also consider the reduction of liability through the implementation of management systems and environmental policies in order to ensure due diligence both with respect to corporate responsibility and the responsibility of the individuals within the corporation.IntroductionConsolidated Professor Mines Ltd . and its predecessor have been exploring in northwestern Ontario for about sixty years . During the last twenty years, the company has been interested in developing a gold mine, the Duport Project, on Stevens Island in Shoal Lake . The lake straddles the border between Ontario and Manitoba and is a drinking water supply for Winnipeg and environs.The Duport Project involves the mining of 450 t/day grading an average of 0.35 oz Ault of ore . At the minesite, located on Steven s Island in Shoal Lake, only preliminary processing of the ore will take place, to produce gravity and flotation concentrates for final gold recover y at a mainland plant well removed from the Shoal Lake watershed. No hazardous chemicals will be used at the island site."

Jan 1, 1991

By R. L. Guerguerian, Eugene Bercel

"Grinding mill hydrostatic trunnion bearings require an external pumping source to provide and maintain the oil film between the bearing members. In order to guarantee a predetermined minimum film thickness, the lubrication system tends to be oversized. The oil film is ""indirectly"" controlled by flow, pressure and temperature monitors with fixed settings on the conservative side. This can lead to excessive maintenance and abbreviated life for the lubrication system components. A reliable method of monitoring actual film thickness would not only provide greater mill availability, but also minimize maintenance costs.This paper describes the instrumentation installed in Dominion hydrostatic bearings, and presents results of field tests where the output of that instrumentation was recorded under various operating conditions.IntroductionThe trend toward larger and more sophisticated grinding mills has made the operators of these machines increasingly vulnerable to financial loss, as the cost of downtime and repairs has increased directly with machine size. In order to guard against such losses, it is becoming imperative that large, sophisticated grinding mills be equipped with protective instrumentation to monitor some of the critical operating parameters and to identify events and trends which, if they go unnoticed, can lead to excessive maintenance costs and machine downtime. The idea of protective monitoring systems is not new. The operators of certain types of machinery where a high degree of safety is required or where machinery health can deteriorate very rapidly, as in the case of high-speed turbo-machinery, have long been using protective instrumentation on their machines. The increased awareness of the benefits of monitoring machinery conditions and the availability of reliable and relatively low-cost instrumentation of a large range of sophistication is making the practice now widespread. Traditionally, grinding mills have not been considered as high-risk machinery requiring instrumented protection. However, the trend, mentioned earlier, toward employing fewer, but larger capacity, mills increases the risk of significant disruption of production, and therefore measures to minimize the risks are desirable."

Jan 1, 1981

By A. A. Lavrinenko, N. I. Gluhova, L. M. Sarkisova, D. V. Makarov

"The investigated sulfide Cu-Ni ores are characterized by low PGE contents and emulgated impregnations of pentlandite and palladium minerals in the main ore-forming mineral pyrrhotite, which hinders their selective separation, requiring a collective flotation of sulfides to concentrate, and hydrometallurgical processing. As revealed by studies of floatability of Pt-Cu-Ni ore in a mixture of butyl xanthate and chelating phosphorus containing reagents, the most effective additive is Aerophine 3416 (a phosphinates mixture) manufactured by Cytec. Using collective flotation with a butyl xanthate – Aerophine 3416 composite in the ratio of 1:3 has afforded to enhance the Pt, Pd, and Ni recovery by 13.6 %, 9.2 %, and 9.4 %, respectively. The optimal ratios of Aerophine 3416 to butyl collector for the collective flotation are the following: 1:1 for Pt and Pd and 3:1 for Ni. The effect of these reagents on the electrode potential and surface hydrophobicity of pyrrhotite, pentlandite, and platinum black has been investigated. The extraction UV spectrophotometry experiments demonstrate that DIBDTPI exists on the pyrrhotite surface mainly in the form of disulfide in weak acid medium and in the form of compounds with Fe on the mineral surface in minute amounts. There appears some disulfide and few amount of (DIBDTPI)2Ni on the surface after interaction of DIBDTPI and pentlanditeINTRODUCTIONXanthates are widely used in flotation of copper-nickel ores containing platinum group metals (PGM) as sulfides collectors which can concentrate the most part of PGM connected with the sulfides. Though xanthates are hardly efficient for flotation of free PGM, the latter are floated more slowly compared to the sulfides of base metals. The reasons for poor floatation of free (mineral) forms of PGM are under-researched, however the key accepted reasons are: fine disseminations of free PGM, insufficient interaction with xanthate and negative influence of blue copperas and sulfur-containing ions which are sulfides oxidation products (Penberthy et al. 1999; Shackleton et al., 2007). That’s why an additional collector, normally dialkyldithiophosphates, is used during flotation of PGM-containing copper-nickel ores. A reagent DP-4 is used for recovery of PGM at Norilsk mining and metallurgical plant. The reagent represents a slightly-soluble organic calcium sulfonate which is given to flotation pulp in the form of water emulsion of 5% - solution in automotive diesel oil."

Jan 1, 2016

By E. L. Warburton

Before entering into a discussion of wet washing, it will be advisable to consider the various phases and conditions sur- rounding the problem of cleaning coal from the Corbin mines. Corbin is located in the south-east part of British Columbia in the Crowsnest Pass district, about 35 miles north of the International boundary and about three miles west of the Flat-head Range of the Rocky Mountains. It is reached by a rail-way, about thirteen miles long, from McGillivray, B.C., a point on the Crowsnest branch of the Canadian Pacific rail-way, owned and operated by the Eastern British Columbia Railway Company, a subsidiary company of Corbin Coals, Limited. The coal is assumed to occur here, as principally elsewhere in the Rockies, in the Kootenai series of the Lower Cretaceous, but owing to the disturbed condition of the surrounding country and, therefore, the magnitude of the geological study involved, this has never been definitely worked out. The coal is of the usual Crowsnest high-grade steam-coal, containing from 9 to 12 per cent. of ash, but appears to have 4 to 5 per cent. less volatile combustible matter than other coals being mined in this district, a representative analysis being about as follows:

Jan 1, 1924

By The Satff

"TEXADA Island is situated in the Strait of Georgia, about 100 miles northwest of Vancouver. The property of Texada Mines Ltd. lies on the southwest coast of the northern end of the Island. A part of the ""Sunshine Coast,"" the climate is moderate, with about 30 inches of rain during winter months and relatively dry summers. Texada has been shipping high-grade magnetite concentrate continuously since 1952 to Japanese ore buyers. In 1959, a 3,000-foot tunnel was driven just above sea level to explore the possible downward extension of known orebodies then being mined by open pit. In January of 1961, because the open-pit operations had a limited life, C. C. Huston and Associates were brought in as mining consultants to do a feasibility study on the possibility of going underground for production. This study was completed in March, 1961. With the completion of the report, the Company went to Japan seeking a ,long-term contract to justify the capital outlay necessary for setting up an underground operation. Concurrently, underground diamond drilling revealed more ore, and the Company planned some modifications to the concentrator for increasing the copper recovery. By November, 1961, a ten-year contract was signed with Japanese ore buyers for the sale of 450,-000 long tons of concentrates beginning in October, 1963. Since that time, the Company has built its own 65 000-ton ore carrier and an additional three-year contract has been negotiated, with an annual tonnage increase of from 450,000 to 550,000 tons."

Jan 1, 1967

By G. M. Ritcey, M. Silver

"The processing of uranium ores produces tailings that could constitute environmental problems. At most operations the tailings are dumped into a designated area, with the ultimate acid drainage occurring if sulphides are present, together with the release of metal constituents to the rivers and streams. If the chemical reactions occurring within the tailings could be predicted, perhaps methods could be developed to either increase or decrease 'the rates of reaction. One such study has been in progress at CANMET during the past three years. The paper describes the use of Iysimeters containing low-grade and complex uranium tailings to determine the effects and interactions of bacteria, sulphides and solvent extraction organics on the release of radionuclides and on acid production. A simulated rain cycle nine-fold the normal was used and the Iysimeters were subjected to timed intervals of light and darkness. As a result, the tests simulated a 25-year period.IntroductionAlthough Canadians derive major benefits from uranium, there are environmental and health consequences, not yet fully understood, from the associated mining and milling operations. A major project at CANMET (Canada Centre for Mineral and Energ y Technology) has the ultimate goal of ensuring that any adverse effects on man and environment, now or in the future, resulting from the processing of uranium should be acceptably low. The magnitude of the task was exacerbated by the fact that the increased demand for electrical energy and the resultant increased prices for uranium oxide during the 1970s led to a rapid expansion in the industry. Annual world demand for uranium was expected to increase 12-15 fold in the next quarter century, with annual requirements of between 200,000 and 300,000 metric tonnes anticipated by the year 2000. Currently, the demand is low and the prices for the oxide have decreased."

Jan 1, 1982

By M. M. Helm

Samples sourced from the Goldstrike property in Nevada USA, have been evaluated in terms of their preg-robbing capacity and the physical structure of the graphitic carbon component in the carbonaceous gold ore. The study highlights a wide range in preg-robbing capacity between samples collected from the Betze-Post open pit and Rodeo underground mine. The physical structure of the graphitic carbon was assessed using Raman spectroscopy, and is found to play an important role in influencing preg-robbing behaviour. Differences observed in the physical structure of graphitic carbon are thought to be the result of hydrothermal events that occurred at Goldstrike.

Jan 1, 2011

By J. P. Messervey

Dr. K. A. Clark: No one will doubt the statement of fact that, during drilling operations through the bituminous sand beds in the Mildred-Ruth Lakes area, the core-barrel was found to contain bitumen with minor amounts of sand instead of bituminous sand. But many will doubt the interpretation of this fact as meaning that beds of bitumen occur interstratified with the bituminous sand beds. They will prefer to hold faith in the laws of physics, which deny that sand will float on oil or that fluid under pressure will not flow away through a permeable medium, until it is proved that the appearance of the oil in the core-barrel was not due to circumstances surrounding the drilling of the bituminous sand beds. The implication of the interpretation that sand is floating on oil is clear and it is unacceptable. Bituminous sand is unconsolidated sand more' or less saturated with a viscous oil. It is as difficult to conceive of bituminous sand lying on top of a body of the viscous oil as it is to conceive of unconsolidated sand more or less saturated with water lying on top of a body of water. The only difference between the two concepts is that the oil is viscous whereas the water is fluid. Oil-soaked sand placed on viscous oil would, when released, sink through the oil slowly, whereas water-soaked sand would sink through the water quickly.

Jan 1, 1947

By Alan F. Stewart, Frederic B. Claridge, Robert S. Nichols

"In recent years, an increasing number of mines in mountainous terrain have examined the possibility of placing mine waste rock into stream valleys. Pressure to utilize stream valleys as a primary location for waste disposal has increased at many of the mines currently under development or expansion. As the number of environmentally and economically ideal wastedumping sites is limited, consideration must be given to utilization of stream valleys. This raises concerns about maintaining water quality in streams passing through or beneath the dumps and potential detrimental effects to dump stability. Commonly, the flows in the streams tend to be flashy, reflecting localized intense storms and rapid runoff in steep-sided slopes within the watershed. These conditions pertain particularly to British Columbia, which is characterized by mountainous terrain and periodically intense precipitation events.The method of conveying flow through a waste dump depends on a number of geotechnical and hydrological factors, including the size, durability and transmissivity of the rock and the design stream flood flow. This paper describes the approach to the design of waste dumps in stream valfeys developed at several mines in British Columbia."

Jan 1, 1986