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By Sean Junor

Cameco Corporation ?One of the world?s largest producers of uranium ?Operations in Saskatchewan, Ontario, the United States and Kazakhstan ?Development projects in Australia ?One of the best employers for Aboriginal Canadians Geographic location ?Remote or northern operations ?Northern Saskatchewan ?Residents of Saskatchewan?s north (RSN) ?Wyoming ?Nebraska

May 1, 2010

By D. J. Parker, G. B. Tupper, I. Govender

Positron-Emission-Particle-Tracking (PEPT) has enabled the non-invasive observation of charge and slurry transport in model mills under operational conditions. We use high quality PEPT data to infer that the charge motion can be effectively described by a non-Newtonian granular fluid. An improved theory for slurry transport, including inertial effects, is presented.

Jan 1, 2012

By C. Jay Hodgson, Adrienne C. L. Larocque

The Mobrun VMS deposit in northwestern Quebec does not fit the classic Noranda type model, but exhibits characteristics more consistent with a Mattabi-type deposit. The orebodies are underlain by fragmental volcanic rocks indicative of explosive volcanism in shallow water. Felsic volcanic rocks are more abundant than mafic rocks. Alteration assemblages comprise chlorite, carbonate, sericite, and quartz. Broad semi-conformable alteration occurs high in the footwall to the 1100 lens. Mobrun occurs higher in the stratigraphic sequence than most of the other deposits in the Noranda camp. In this part of the stratigraphy, zones of pervasive carbonatization may be more useful guides for exploration than zones of silicification.

Jan 1, 1993

By Charles Tkaczuk

Key issues ? Process control is a corporate function implemented locally. ? Security and documentation is mandatory requiring standard practices. ? Publish and communicate activities (do not re-invent the wheel). ? Payback metric system for all projects. ? Partnering with vendors based on experience, expertise and joint R&D. ? Focus on phased process control projects and distribution of costs. ? Integration of services and functions. ? Application of global standards. ? Big picture application thinking.

Apr 1, 2005

By Robert Lamarre

In today?s environment, the availability of production equipment is a must to increase throughput and profits. For a number of mining organizations around the world, spare parts availability is key to achieving this goal. Fortunately, having less production equipment immobilized by a lack of spare parts does not equate to increases in inventory levels or in carrying costs. Advance operations research has shown a number of avenues to increase equipment availability while reducing total investment in stock. The presentation will explore these avenues by focusing on key inventory management changes that can be implemented by organizations to optimize their service and stocking levels. We have successfully applied our approaches in start-up mining projects, in mature projects and in end of life mining operations. We will illustrate our methodology using examples from our work with > 30 mining sites around the world.

Aug 1, 2013

By J. S. Scott

"The Quemont property comprises 640 acres lying directly north of and adjoining the Noranda (Horne) mine. During 1926 to 1928, United Verde Extension Mining Corporation sank a shaft 235 feet and did 3,000 feet of development work on the 215-foot level. Between 1929 and 1930, Quemonr Mining Corporation deepened the shaft to 926 feet, and did further lateral work and drilling on the 500- and 900-foot levels. This work was confined to an area close to the south boundary and met with little encouragement.Following a period of idleness a magnetic survey was made in the winter of 1944, followed in the summer of the same year by some 6,000 feet of drilling. The first successful hole was drilled in February, 1945, from the ice of Osisko lake.To the time of writing, 131,000 feet of drilling, surface and underground,have indicated a large tonnage of gold-silver-copper-zinc ore, and although some knowledge of the geology and structure is emerging, it is too early to draw definite conclusions. The following brief description deals only with those structural features that are reasonably well indicated."

Jan 1, 1954

By A. J. Williams, W. H. A. Timm

"Lake Dufault Mines, Limited, is located north of Noranda, Quebec, and is a producer of copper and zinc concentrates. Various papers have been given on the mill design, construction and operation. 1, 2This paper is intended to describe the application of computer control to the Lake Dufault milling process. A brief history and description of the plant flowsheet will be given, followed by the reasons for installing the computer and the development of the program up to its present use. The success attained to date, comments on economic justification and future plans will also be given.HISTORY AND FLOWSHEETThe Lake Dufault ore body was discovered in September, 1961, and the mill commenced production during August, 1964. The rated capacity of 1,300 tons per day was reached by October 1, 1964. In milling the Lake Dufault ore, many metallurgical problems have been encountered, mainly due to wide and rapid variations in mill heads and oxidation of the massive sulphide ore. However, flexibility in plant layout and the incorporation of up-to-date instrumentation have facilitated its processing."

Jan 1, 1969

By Tiago Webber

Mineral resources estimation comprises basically two stages: (i) data collection, analysis and validation, and (ii) the estimate of the grades and tones of the deposit. The most applied method for sampling survey in mineral exploration is rotary drilling with total core recovery. High drilling costs make borehole geophysical logging attractive to obtain the maximum possible information from each borehole helping to understand ore intersections, grades variability, limits of the deposits and continuity of the mineralization. In this paper, borehole geophysical logging was used to enhance the sampling survey and to derive grades indirectly (without lab analysis) with a certain amount of uncertainty. Indicator kriging (IK) was the estimation method used, as it is adequate to incorporate the uncertainty associated with the geophysical derived grade values. The results were compared to the conventional procedures using grades determined via core analysis and ordinary kriging. Borehole geophysical logging proved to be efficient to define the essential features of ore deposit and IK provided results with acceptable precision and accuracy if compared to the model provided by ordinary kriging.

Oct 1, 2009

By Tyson C. Birkett

Initial indicator mineral sampling covering 425,000 square km of northern Quebec and subsequent follow-up of positive results convinced the Ashton ? SOQUEM joint venture to acquire mineral rights to 380,000 hectares prospective for diamond in late summer, 2000. Drilling in 2001 and 2002 identified eight kimberlitic bodies, all significantly diamondiferous. Commercial size stones (retained on a square mesh sieve with openings 0.85 mm) and encouraging grades have been returned by several bodies tested to date: The Renard bodies are formed by steep-sided breccia pipes with kimberlitic matrix surrounded by irregular outboard breccia zones within country rock. These bodies were emplaced in high-grade metamorphic rocks of the Superior Province of Archean age. Orthogneiss with lesser tonalite hosts the breccias, although regionally paragneiss is also present. Diatreme facies portions and nearby country rock are intruded by minor to major (Renard 1) amounts of hypabyssal-facies kimberlitic rock. Renard bodies are macrocrystic, with large olivine crystals set in a groundmass of olivine, phlogopite, monticellite, spinel, carbonate, apatite and serpentine. Proximity of various Renard bodies, with most in a core area of 0.5 square km will allow planning of an efficient mining operation. Geophysics, especially magnetic surveying, has contributed to identifying bodies of kimberlitic rock.

May 1, 2003

By Cristina Echavarría

MAIN POINTS ? The region: opportunities and limitations ? Overview of main issues emerging from MMSD in South America ? Who comprises the local community? ? What are the main challenges? ? Some suggestions for companies to improve their contribution to local sustainable development of mineral rich localities THE REGIONAL CONTEXT 1. The region is a producer of minerals contributing over 20% to world metal production. It consumes only 8% 2. Significant diversity of national contexts-both between countries and within countries 3. Variable but predominant need for strengthening of government and community institutions and governance, especially at the local level 4. Dearth of baseline information for decision making 5. Sustained social spending during early 90?s as a consequence of economic recovery and fiscal policy, produced important advances in education and health 6. Despite government efforts in most countries poverty continues growing 7. Highly inequitable distribution of wealth persists

May 1, 2002

By C. Allen, M. Gangal, J. Stachulak

"Most underground diesel equipment is equipped with diesel oxidization catalysts (DOCs) to reduce carbon monoxide and hydrocarbon emissions. DOCs do not alter nitrogen oxides concentrations but can promote the oxidization of nitric oxide (NO) to the more toxic nitrogen dioxide (NO2). Vale and CanmetMINING have been researching how to reduce worker exposure to diesel emissions by testing mining equipment DOCs. Results indicate a > 77% decrease in carbon monoxide concentration but a 46–315% increase in NO2 concentration for 8-mode test cycles. It is recommended that DOCs that increase NO2 emissions be evaluated regarding their continued use in underground operations.RÉSUMÉ La plupart des équipements miniers souterrains sont équipés de catalyseurs d’oxydation diesel (DOC) afin de réduire les émissions de monoxyde de carbone et d’hydrocarbures. Les DOC ne modifient pas les concentrations des oxydes d’azote mais ils peuvent faciliter l’oxydation du monoxide d’azote (NO) en dioxyde d’azote (NO2), plus toxique. Vale et CanmetMINING effectuent des recherches pour réduire l’exposition des travailleurs aux émissions de diesel en analysant les DOC des équipements miniers. Selon les résultats, une diminution > 77 % dans la concentration de monoxyde de carbone est atteinte mais elle est accompagnée d’une augmentation de 46 à 315 % de la concentration en NO2 pour des cycles d’essais à 8 modes. Il est recommandé d’évaluer les DOC qui augmentent les émissions de NO2 pour décider de la poursuite de leur utilisation dans les opérations souterraines."

Jan 1, 2016

By Karl Houseley, Dr. Robert J. Chapman

"A gravity concentration process has been applied to ores from the Clogau Mine, north Wales, the Tyndrum deposit, central Scotland and an alluvial ore from Leadhills area of Scotland. In the case of the Welsh ore and the alluvial deposit the gold grains in the concentrate and tailings streams have been characterised in terms of their three dimensions.In the case of Welsh ore, the thickness of a gold grain has been shown to be the single most important factor in determining behaviour in a gravity concentration operation. Six indices were used to quantify the overall geometry of the gold grains and those which incorporate a thickness term have proven to be effective in predicting the destination of gold particles within the concentration circuit. It is proposed that the most simple of these, the Heywoods flakiness ratio, has potential for the control of milling operations as an alternative to the established practice of characterising the size of the mill discharge.The effect of grain geometry on the recovery of fine gold has been studied using Tyndrum ore. The recovery of gold by gravity concentration increased from 20% to 70% when the criteria used to design the milling operation was the prevention of over grinding of gold grains.The destination of alluvial grains in the concentration circuit did not show such dependence on shape, and this has been attributed to the effective classification of all the gold grains in the sample by fluvial action producing a population of similar geometric characteristics."

Jan 1, 1996

By Dwayne D. Tannant

The Fox Pit at EKATI Diamond Mine reached a depth of approximately 150 m as of September 2005. The pit is designed with 11 m wide benches excavated using a double benching technique leaving 30 m high bench faces. A series of blasting tests were conducted to improve catch bench reliability and increase the percentage of benches that meet an 11 m catch width. The design changes focussed on reducing damage to the bench crest because maintaining the bench crests is the most important factor in achieving good bench reliability. The most significant improvement was obtained by raising the bottoms of the lower trim blastholes by 0.5 m. This change decreases the depth of broken rock below the final bench elevation, and consequently reduces damage to rock that forms the bench crest below. Another improvement was the use of smaller diameter (165 mm vs. 270 mm) blastholes in the A and B rows for the upper trim blast. This change reduces the charge per delay during detonation, reduces the powder factor slightly, and reduces the energy affecting the final pit wall and crest. As mining and the blast testing progressed, the portion of the bench with crest achievements (>11 m) increased from 57% to 75%.

May 1, 2006

By O. Laitinen, M. Rudolph, J. A. Sirviö, H. Liimatainen, R. Hartmann, University of Oulu

The increasing complexity of the ores composition worldwide calls for suitable collectors with specific properties, such as selectivity, wettability, and in regard to current regulations, environmental sustainability. Therefore, collectors have to satisfy many features to improve the efficiency of flotation processes. Cellulose nanocrystals gain more and more interest due to the versatile synthesis routes which enable the integration of specific functional groups and components with different degrees of hydrophobicity within the molecular structure. Consequently, cellulose nanocrystals can be employed in flotation processes as depressant or collector molecules, respectively. Nonetheless, the usage of cellulose nanocrystals is still limited due to a lack of the characterization of nanocrystal-mineral interactions and the change of the surface wetting properties of minerals after adsorption phenomena between nanocrystals and minerals. In these studies, butyl-amine cellulose nanocrystal (BAC) and quartz are used as model system to investigate physicochemical properties of both, BAC and quartz, and examine the applicability of BAC in flotation processes. Therefore, the surface charge distribution and electrophoretic mobility of BAC and quartz are investigated and compared to understand the effect of electrostatic interactions between BACs, and BAC and quartz. Based on this, the adsorption of BAC on quartz is examined. Finally, microflotation experiments test the efficiency of BAC to be used in flotation processes. The flotation response is correlated to the specific surface charge of BAC revealing the dominant effect of surface charges on effective particle-bubble adhesions.

Jan 1, 2016

By W. S. (Steve) Vaughan

The Origins of Joint Ventures in Canada?s Mining Industry ? Among the most important financing structures used in our mineral industry today ? Virtually unheard of in the Canadian industry prior to the 1970s ? Borrowed from the U.S. oil and gas sector where it came into prominence in the late 1930s ? The Securities Acts of 1933 and 1934 in effect killed the sale of (equity) shares for financing oil and gas wells and start up mining companies

May 1, 2013

By Jose A. Jimenez

"Mining operations generate an enormous amount of data that is difficult to organize, analyze and act on. These data require an extremely broad range of experts to investigate and manage the cross-disciplinary information. The data collects in paper files, diverse databases, historians, stand-alone applications, and excel files. This collection of sources represents everything from monthly, weekly, or daily inputs to real-time feeds or sporadic unscheduled entries. With the operational complexities ever increasing and fewer engineers per mine, an efficient operation is becoming more and more challenging. Engineers are typically burdened with data collection, clean up, and administrative efforts leaving very limited time for engineering assessment and/or optimization analysis. Often optimization becomes limited to the analysis of equipment uptime through existing field automation systems. A great portion of the field data is tucked away in historians seldom reaching those engineers who might leverage the data. Few mine operators have the time or budget to re-architect their operations data collection or management practice, so solutions must enable improvements without requiring expensive or time-consuming implementation. This presentation highlights examples where the aforementioned challenges are addressed using a solution framework designed to enable: 1) data integration and connectivity, 2) monitoring and opportunity recognition, and 3) engineering workflow automation. The initiative extends the concepts and success proven in the automation market segment to all disciplines across the mine operations. INTRODUCTIONThe mining industry by its very nature spends a great deal of its capital on equipment maintenance and replacement. In addition, periodic shutdowns due to equipment failure are typically very costly in terms of interrupted operations. Keeping mining equipment running at peak performance and avoiding costly shutdowns can make a huge difference in the overall return from mining operations. Today, information can be make available that can go a long way towards spotting equipment issues and permitting timely intervention to avoid costly unplanned shutdowns. That said, gathering all of the information from numerous points on many different pieces of equipment necessary to enhance overall equipment effectiveness presents its own daunting issues."

Jan 1, 2016

By D. H. Wilson

"This paper examines the increasing need for mechanical-electrical people within the industry and some of the reasons why such a shortfall exists. It is suggested that, in part, it is image related. The present industry-education relationship in addressing the situation is examined and some thoughts are expressed on how these may be built on, in order to help solve the problem of attracting people to this critical area.IntroductionAs a long-time proponent of plant engineering and maintenance as a management function, I would like to review the progress made by the industry/ educational approaches in satisfying the needs in that area. In doing so, I would like to make the following points:1) that there has been an accelerating shortfall of mechanical-electrical people relative to the needs of the industry;2) that the condition will probably get worse before it gets better; ,3) that the past industry I educational approaches to alleviate the problem have met with limited success; and finally4) I would like to review some of the things being done and consider how these efforts might be extended."

Jan 1, 1981

By I. J. Burgess, B. C. Barlow

"The electrodissolution of nickel pellets with different controlled electrical variables was investigated in an effort to mitigate plating residue in Watts bath based electroplating cells. During galvanostatic dissolution at 0.4 A dm-2, the anode potential was seen to oscillate between passive and pitting potentials. In-situ microscopy and ex-situ characterization has shown that lacy-pit formation and large, partially perforated, pit covers form during the potential decay from pitting potentials. In general, covered pitting at low current density shows increased plating residue. Using potential pulses is one way to maintain greater control over surface pitting by creating a higher density of pit nuclei while at the same time controlling their growth. Pits generated from a series potential pulses were examined ex situ for a range of pulse times and stages of pit growth were identified. An alternative method of anode dissolution was devised using potential pulses and duty cycles that allowed average current densities comparable to industrial plating conditions to be achieved. By restricting the time at pitting potentials to 0.05 s, plating residue was reduced more than six-fold in comparison to an equivalent galvanostatic experiment run at a comparable current density.INTRODUCTIONIn typical galvanostatic (direct current) nickel electroplating cells employing soluble anodes, some amount of plating residue is produced which consists of metallic nickel and impurities that detach from the bulk in the form of small fines. Significant buildup of residue requires plating operations be halted and the anode assembly cleaned of residue before operation can resume. While variables in the refining process have been shown to affect plating residue, more precise control of electrochemical variables may provide an attractive route to mitigation of residue."

Jan 1, 2016

By Leopoldo Gutierrez, Sergio Castro, Lina M. Uribe, Janusz S. Laskowski

"The effect of sulfite and metabisulfite ions on the amyl xanthate flotation of copper-activated pyrite, in distilled water and seawater, has been studied by micro-flotation tests and redox potential measurements. The activation of pyrite was carried out varying copper ions concentration. It was found that in the presence of copper ions in solution, sulfite and metabisulfite are able to depress copper-activated pyrite at neutral or slightly acid pH. After the addition of sulfite or metabisulfite ions the resulting pH is more acidic with metabisulfite ions. A significant increase of the redox potential of the solution was observed as copper ions concentration increased. Then, the initial reducing conditions brought about by sulfite and metabisulfite ions, change abruptly to oxidizing conditions in the presence of copper ions. Under these oxidizing conditions, the metabisulfite showed to be an effective depressant for pyrite mainly in seawater. However, sulfite was a pyrite depressant in both distilled water and seawater. Based on these results, the pyrite depression by sulfoxy-depressants during the flotation of Cu/Mo ores in distilled water and seawater is discussed.INTRODUCTIONDepression of pyrite by sulfoxy-depressants (sulfite and metabisulfite) in the presence of copper ions is an important issue. This is particularly true when pyrite depression in the flotation of Cu/Mo sulfide ores is carried out in seawater. The use of lime in seawater must be avoided because the formation of magnesium hydroxy-complexes and precipitating magnesium hydroxide strongly depresses molybdenite flotation (Castro et al., 2014). In order to solve this problem, one large plant in Chile uses sodium metabisulfite (MBS) instead of lime to depress pyrite in seawater. In plant practice, this also improves molybdenite flotation since with the use of MBS the pyrite depression is carried out at pH 6-7, instead the pH 11-12 usually employed with lime.From a general point of view, pyrite exhibits some natural floatability over acidic pH ranges and may be partially floated without thiol collectors (a coating of sulfur/polysulfides has been claimed). Therefore, pyrite flotation with xanthates is usually high in the acidic pH region, but decreases greatly at alkaline pH (Leppinen, 1990; Fornasiero and Ralston, 1992; Zhang et al., 1997)."

Jan 1, 2016

By Frank Baczek, R. Q. Honaker, D. P. Patil, B. K. Parekh

Fine refuse slurry impoundment is a requirement for the coal industry to dispose the fines. Impoundment maintenance is an on going problem for the coal industry and its breakage creates environmental as well as financial problems. Deep Cone thickener technology which has been successfully applied in the alumina industry to dewater red mud was evaluated for fine refuse slurry. Preliminary obtained in a pilot-plant test showed that properly flocculated conventional thickener underflow slurry could be thickened to about 52.5 wt % solids and could replace belt filter press. The Deep Cone thickener was also found to dewater clean coal slurry to about 70 wt % solids. Further testing of the unit at other coal preparation plant is in progress.

Jan 1, 2004