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By G. P. Gu

The in-service 90/10 cupro-nickel tubes in a water-chiller system suffered from severe corrosion damage during their relatively short service life causing unexpected down time. In addition to downtime, the environmental risk associated with losing refrigerant was also a concern that initiated this investigation, Microstructural investigation using SEM and electron microprobe indicated that pitting corrosion had resulted in local nickel depletion, During the corrosion process, copper appeared to have re-deposited around the corrosion pits accelerating the local corrosion.

Jan 1, 2005

By J. L. Bowlby

TWO years ago, at the annual meeting of this Society, the writer presented a paper dealing with various aspects of the water problems existing in the Cape Breton coal-mining area. Much of that paper was of a theoretical nature, in that an attempt was made to get at the fundamental principles underlying the problems, in order to establish a sort of background against which future results could be laid. Up to that time, only Central power plant in Glace Bay had been under observation, and, since the work had been in progress only a year, it was recognized that there were strong possibilities that certain variations in procedure might have to be introduced as w; became better acquainted with our problem. We were by no means certain that we had covered all the facts of the case. The present paper will therefore be of the nature of a progress report, rather than a formal contribution to the Society. Subjects of a theoretical or academic nature will be avoided as far as possible, attention being confined chiefly to the results obtained during the past two years. In looking over the work with low-pressure boilers, there are certain general conclusions that can apparently be safely drawn. Wherever possible, proper operating conditions will be expressed in terms of appropriate units. Absence of corrosion in boilers where the alkalinity has been maintained within the pH range 11.0 to 11.4 forces one to the conclusion that these are safe working limits. Previous experience had shown that corrosion would occur if the alkalinity were much reduced. Higher alkalinities are un-necessary, more expensive, and are said to introduce the possibility of pitting. We made no attempt to obtain quantitative data in respect to pitting. It is said to occur at pH 12.0. Consequently, conditions of alkalinity were main-tained well below this figure. In the above paragraph, the pH range 11.0 to 11.4 applies to boiler waters which have received the lime and soda treatment. The general practice, when this treatment is employed, is to use 1.0 lb. lime to 7.0 lb. washing soda. At Central power plant, soda-ash is at present substituted for washing soda, the equivalent proportions being kept the same. But not all the plants are on the lime and soda treatment. At Waterford Lake, a 1: 1 mixture of soda-ash and trisodium phosphate is satisfactorily employed, and in Sydney Mines and at No. 3 power plant in Sydney, good results are being obtained at a somewhat greater cost with a commercial phosphate treatment.

Jan 1, 1936

By Davis Myers

OVERVIEW ?A summary of population demographics data ?Potential impact of Baby-Boomer, Generation X, Millennial demographics in the mining workforce ?Planning with constrained resources Age Cohorts ?Baby Boomers: born 1946 -1965 ?Booming economy, TV, cold war, JFK, Vietnam ?Generation X: born 1965-1980 ?There was always space travel ?PC?s, Black Monday, Challenger, Desert Storm, fall of Berlin Wall ?Millennials: born 1980-2000 ?There was always the internet ?IM, Facebook, Sept 11, Columbine

Nov 1, 2011

By Yugo Mitani, Tatsuya Kato, Chiharu Tokoro, Abdullah Al Mamun

Acid mine drainage (AMD), which is a major source of mining pollution, often contains ferric and/or ferrous ions together with several toxic elements. The ferric and ferrous ions in AMD precipitate in several mineralogical forms after neutralization, and the ferric/ferrous precipitates become the main component of the sludge generated after AMD treatment. The precipitates are also good absorbents for several toxic elements. To avoid generation of voluminous sludges and the re-dissolution of toxic elements from the sludge, it is very important to generate well-draining and efficiently adsorbing sludges by controlling the mineralogical form of the ferric/ferrous precipitates. Green rust, which is ferric and ferrous hydroxide, is a double layer hydroxide which is able to sorb several toxic elements. The green rust transforms to goethite or lepidocrocite by rapid oxidation, whereas it transforms to magnetite at ambient temperature by slow oxidation. The magnetite is also good absorbent especially for toxic cations and it makes a compact sludge due to its magnetic properties. We investigated the magnetite generation process at ambient temperature in detail. The magnetite generation process can be divided into three steps; (i) oxidation of Fe(II), (ii) Fe(II) surface complexation to Fe(III) hydroxide, and (iii) crystallization of magnetite. More magnetite can form when the oxidation rate is slower than the crystallization rate, and optimum conditions for its formation are at pH 9.5 with mild agitation. Ferrihydrite is the most common precipitate and it is able to sorb many different toxic elements. However, it drains badly and its solid/liquid separation properties are poor. We investigated the removal mechanism of several toxic elements by co-precipitation with ferrihydrite. We confirmed that the removal mechanism by co-precipitation partly involved surface precipitation when the initial ratio of toxic elements to ferric ion was high, although the main mechanism was always surface complexation. When surface precipitation occurred, highly efficient toxic element removal with ferrihydrite could be achieved.

Jan 1, 2016

Partnership with MiHR ? AHRC and MIHR jointly developed Mastering Aboriginal Inclusion for Mining ? Customization specific to mining Mining is unique? ? History of Aboriginal peoples and the land ? Unique community needs ? Effects of Impact Benefit Agreements ? Remoteness of mines ? 1200 Aboriginal communities located w/in 200km of active mines or exploration ? Long term effects of the land

May 1, 2009

By Michael Fuller

Roadmap ? Examples of Partnership from UBC ?? Event Sponsorship ?? Recruitment & Connections ?? Opportunities ? National Recruitment Survey Results ? Conclusion with Key Points Event Sponsorship ? Annual Canadian Mining Games competition ?? 160 senior mining engineering students, from 10 universities ? Field Trips ?? 2nd year: Open pit ? Highland Valley Copper ?? 3rd year: Underground ? Myra Falls, Quinsam Coal ?? 4th year: Self-organized ? Chile, China, Poland, Brazil

May 1, 2008

The following briefing is intended to provide an overview of the present and future challenges associated with our access to a secure and adequate supply of electrical energy necessary to support safe, productive and sustainable mining initiatives at Musselwhite. Contents ??Site power demand vs. current available supply ??Supply technical deficiencies ?adequacy and security of present supply ??Present internal generation ??Anticipated future internal generation requirements ??Increased requirements necessary for planned expansion ?demand/security ??Goldcorp?s strategy to achieve required supply ?transmission line initiative ??Subsequent benefits to others from the Goldcorp initiative. ??Economic impact of MusselwhiteMine on the northwest region ??Anticipated economic impact of planned expansion ??Expected life cycle of MusselwhiteMine ??Comparative energy costs for similar operations in other jurisdictions ??Conclusions ??Anticipated action plan ??Energy Management Initiatives ??Site Orientation

May 1, 2009

By S. McCarthy, K. E. Waters, A. Jordens

The beneficiation of rare earth (RE) element bearing minerals has become an active area of research as applications for these elements grow while the supply to non-Chinese consumers is restricted by export quotas. One of the most interesting beneficiation techniques for RE minerals is froth flotation as their unique chemistry suggests that collectors with a specific affinity for RE cations should be able to selectively recover these minerals. Existing literature, focusing mainly on bastnäsite flotation, identifies hydroxamic acids as excellent collectors for RE minerals. The high stability of hydroxamate-RE cation complexes is the explanation most often offered for the observed selectivity of these reagents in bastnäsite flotation however some research has also suggested that mineral solubility plays a crucial role in the success of hydroxamic acid flotation of RE minerals. This work investigates the interaction of allanite, a relatively insoluble RE-silicate mineral, with benzohydroxamic acid using zeta potential measurements and microflotation. The effects of Fe(III) and Fe(II) ions as potential activating ions (cations that form stable hydroxamate complexes) on benzohydroxamic adsorption to the allanite surface are investigated as a potential solution to promote hydroxamic acid adsorption. The results indicate that the optimum conditions for separation of allanite from quartz occur at pH 4 using FeCl2 as an activator for benzohydroxamic acid adsorption.

Jan 1, 2014

By C. Tan, A. Putz, P. Lacombe, R. Kemp, M. Kaya, B. J. Huls, A. R. Laplante

"This paper concentrates on the four recent plant trials/ applications of froth washing. Results showed that improved metallurgical performance can be achieved with wash water. Increased froth cleaning yielded better upgrading, and some cases slightly improved recovery. Froth sampling and salt tracer tests supported the findings of froth washing tests.At Falconbridge, Ni grade increased from l.47% to 2.15% and recovery from 85% to 87%. At Eastmaque, final Au grade increased from 2.3 to 2.7 oz/st at a slightly higher recovery. At Les Mines Selbaie, Cu grade increased from 24.5% to 25.S% and Zn grade from 54.5% to 56.l%. At Zinc Corp. of America, average Zn grade increased from 55% to 56. 8% at the same recovery for a 45-day period. A number of plants in Canada and the United States have evaluated and/or now practicing froth washing. Wash water has now proved itself in some plants over several months of operation.INTRODUCTIONFroth washing in mechanical flotation cells offers a number of metallurgical (i. e. increased grades and/or recoveries) and economical (i.e. decreased transportation and smelting & refining costs) benefits. Fundamental development work in laboratory and pilot scales performed at McGill yielded encouraging results. (Kaya and Laplante, 1988a and 1989a). Since laboratory and pilot flotation performance can differ from full-scale due to differences in hydrodynamics, kinetics, and froth characteristics (e.g. stability, loading etc.), plant trials were essential to prove the viability of this technology."

Jan 1, 1990

By M. Thérien, M. Rémillard

"Data from two industrial plants are treated by mass balance package BILMAT. The first application concerned a base metals/precious metals (PM) producer and the second, implementation of a hydrocyclone for the recovery of iron chips in the granite industry. Also LOTUS 123 software can easily be adapted for laboratory test mass balances using an IBM-PC computer. INTRODUCTIONThe present paper deals with two different BILMAT program applications. The first application concerns a copper-zinc-gol d-sil Yer producer based in North-western Quebec and the second, concerns the iriplementation of a hydrocyclone for the recovery of iron chips in Quebec granite company.Afterwards, we deal with some LOTUS 123 software applications for laboratory test mass balances using an IBM-PC.1. Base metal and P.M. producerNoranda Inc, Mattagami division, which operates mines in North Western Quebec, produces copper and zinc concentrates from a sulphide ore. Small amounts of gold (0,34 g/t) and silver (20 g/tl are present. At the time of the study, only 30% of the silver content was recovered in the copper concentrate. The main objective of this study is, to evaluate the metallurgical behaviour of silver in the flotation circuits, to increase its recovery in the copper concentrate and therefore to improve its final economic value. It is then worthwhile to identify the silver bearing minerals and to determine the critical flotation stages where they are lost. The methodology proposed is based on the coupling of a mineralogical study and a detailed mass balance ca1cu1ation in the flotation circuit performed using the BILMAT mass balance package (1, 2, 3).The results are discussed with respect to the distribution of silver in the circuit. The recoveries obtained at the various separation stages for the minerals present in the ore are also discussed."

Jan 1, 1987

By P. J. Oakley, W. M. Thomas, S. W. Kallee, D. G. Staines

A Friction stir welding (FSW) is now extensively used in aluminium industries for joining and material processing applications. The (FSW) technology has gained increasing interest and importance since its invention at TWI almost 15 years ago. The basic principle, recent applications and the continuing development of the FSW technology are described. The paper will introduce some of the variants of FSW, such as Dual-rotation, Twin-stir(TM), and the Stir-lock(TM) technique.

Jan 1, 2006

By J. G. Peacey, G. Csicsovszki

The target of this study was to clarify the role of lead on the dissolution of gold in the (NH4)2S2O3-Cu leaching system via chronopotentiometry, linear sweep voltammetry and chronoamperometry. It was found that the dissolution of gold was significantly increased with lead concentration up to 10 mg/1 Pb in the system of 0.1 M (NH4)2S2O3 and 50 mg/1 Cu. \/oltammograms suggested that the anodic dissolution of gold was virtually independent of lead concentration in the range of 1-10 mg/1 in 0.1 M (NH4)2S2O3 solution while in solutions containing copper as well, addition of lead increased the anodic dissolution of gold.

Jan 1, 2011

By Karol Kostúr

This paper briefly describes the current state of underground coal gasification (UCG) processes globally and in the Slovak Republic. Recent results of laboratory and technical tests are presented. In addition, on site measurements have added new knowledge of UCG technology. A series of laboratory tests based on physical models shows promise for managed UCG process control.

Aug 1, 2013

By Zhanyou Huang

The logic and capabilities of a short-term planning tool are presented. It was developed using mixed integer linear programming (MILP) techniques to solve the open-pit and underground mine planning problems that include multiple mining areas, multiple processes, multiple destinations and blending requirements. It finds the optimum schedule that achieves the objective while satisfying comprehensive product quality and quantity requirements, equipment utilizations, as well as physical and technical constraints. A case study is given to demonstrate its applications.

Oct 1, 2009

By Zhanyou Huang

The logic and capabilities of a short-term planning tool are presented. It was developed using mixed integer linear programming (MILP) techniques to solve the open-pit and underground mine planning problems that include multiple mining areas, multiple processes, multiple destinations and blending requirements. It finds the optimum schedule that achieves the objective while satisfying comprehensive product quality and quantity requirements, equipment utilizations, as well as physical and technical constraints. A case study is given to demonstrate its applications.

Oct 1, 2009

By S. Ghafarnejad Parto, Å. Rasmuson, A. Fredriksson, M. Mohammadi, K. M. Forsberg, J. Martinez De La Cruz

The present study aims at recovering rare earth elements (REE) in conjunction with the production of fertilizers from an apatite concentrate. Apatite is one of the REE rich minerals ending up in the tailings pond when Luossarvaara-Kiirunavaara AB (LKAB) in Sweden processes Malmberget’s iron ore deposit. Leaching with nitric acid, hydrochloric acid, and sulphuric acid respectively have been studied. The nitric acid route was chosen for further investigations and the optimum acid concentration for leaching of the REE were determined. The leached REE are recovered by solvent extraction using di-(2-ethylhexyl) phosphoric acid (D2EHPA) and 2-ethylhexylphosphonic acid-mono-2-ethylhexyl ester (EHEHPA).

Jan 1, 2014

By Patricia Dillon

EHS Management Standards Communication and Reporting (8) ! Establish processes for internal and external communications ! Designate responsibilities for communication with COI ! Report as defined by senior management ! Report annually to employees, shareholders, COI on EHS and social performance Community Rights and Public Consultation (9) !Identify COI?s and establish process to hear concerns !Acknowledge and respond to complaints !Support local communities !Plan for closure and conduct public consultation !New projects include identification of COI?s, concerns to be considered in design

May 1, 2004

Abstract-This paper discusses the fundamental question, "what is an adequate sample size?" in the light of recent developments regarding parameters of Gy’s well-known formula for predicting sampling variance. New understanding of the granulometric factor, g, and the liberation factor, l, had significant impact on the results of calculations involving Gy’s equation. For the granulometric factor, justifications are given as to why nominal comminution size should always be reported as P95 (i.e., the screen size rejecting 95% of the mass). A small but important change in the model to estimate the liberation factor makes the difference between a predictive formula that works or does not. Other parameters and considerations regarding their practical implementation are commented upon in light of the author’s experience.

Jan 1, 1998

By W. Lamb

Feed Preparation ? Five primary parameters affect the screening efficiency ? Ore characteristics ? Operational characteristics ? Screen characteristics ? Water addition and washing ? System design

Apr 1, 2005

By J. A. R. Faucher

"Autogenous grinding may be an efficient and economical solution to your ore comminution problem.An important potential economic advantage of autogenous mills results from the availability of very large capacity units.Autogenous grinding could be more economical in terms of both capital and operating costs.Satisfactory pilot plant testing and thorough economic evaluation are required for a sound decision in comminution plant selection.INTRODUCTIONMankind's first weapon was probably the wooden club, but men soon learned to shape, smooth and polish stone for tools and weapons by pounding and rubbing them with sand and water. It was only about four thousand years ago that rocks were first broken to concentrate, smelt and return the metals they contained. In spite of our recent great technological advances we still break rock in essentially the same manner that was used thousands of years ago - by pounding, rubbing and squeezing - and we still waste much energy and metal in the process"

Jan 1, 1969