Zen and the art of specification writing

CIM Journal, Vol. 5, No. 1, 2014
R. A. Nemchek
Independent Consultant, Parker, Colorado, USA
La conception d’usines de concentration a grandement évolué d’un grand nombre de petits broyeurs vers un petit nombre de gros broyeurs. C’est pourquoi le rendement des usines tient souvent de la productivité d’un seul gros broyeur semi-autogène. Les efforts de l’industrie pour traiter de la nature critique des broyeurs a souvent conduit à des spécifications qui pourraient être simplifiées, rendues plus économiques et qui cibleraient mieux les objectifs du projet. Le présent article analyse les pratiques courantes de rédaction de devis et propose une approche améliorée qui reconnaît que la réussite d’un projet dépend de l’interdépendance de la conception du produit, de l’approvisionnement, de la fabrication et de la qualité. Les leçons apprises ici peuvent être appliquées aux spécifications de tout type de machinerie.
Résumé La conception d’usines de concentration a grandement évolué d’un grand nombre de petits broyeurs vers un petit nombre de gros broyeurs. C’est pourquoi le rendement des usines tient souvent de la productivité d’un seul gros broyeur semi-autogène. Les efforts de l’industrie pour traiter de la nature critique des broyeurs a souvent conduit à des spécifications qui pourraient être simplifiées, rendues plus économiques et qui cibleraient mieux les objectifs du projet. Le présent article analyse les pratiques courantes de rédaction de devis et propose une approche améliorée qui reconnaît que la réussite d’un projet dépend de l’interdépendance de la conception du produit, de l’approvisionnement, de la fabrication et de la qualité. Les leçons apprises ici peuvent être appliquées aux spécifications de tout type de machinerie.
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Publication: CIM Journal
Numéro: 1
Volume: 5
Année: 2014
Texte
Sommaire: Wash water and polyethylene oxide (PEO) were used in the flotation of quartz and coal. Wash water decreased entrainment of –15 μm quartz. The optimum superficial wash water rate was 0.05 cm/s. PEO also lowered entrainment. The combination of wash water and PEO led to a slight further reduction in entrainment. For 1:1 mixtures of –15 μm quartz and –300 μm oxidized coal, the combined use of wash water (0.05 cm/s) and PEO increased the separation efficiency from approximately 30% to > 70%,...
Publication: CIM Journal
Auteur(s): H. Wang and M. Cao
J.-C. Sztuke and A. Stradling
Z. Xu and Q. Liu
Mots clés: Polyethylene oxide, Coal flotation, Quartz, Entrainment
Numéro: 1
Volume: 5
Année: 2014
Texte
Sommaire: We conducted a series of numerical experiments to investigate the influence of rock mass foliation on impact-induced damage on ore pass walls. The 2D Particle Flow Code was used to simulate three distinct rock masses surrounding an ore pass, characterized by foliation angles of 60°, 90°, and 120° (clockwise from horizontal). Subsequently, we projected a rock fragment against the ore pass walls at a constant impact angle and velocity. The resulting damage increased when the angle of intersecti...
Publication: CIM Journal
Auteur(s): K. Esmaieli and J. Hadjigeorgiou
Mots clés: Ore pass, Foliation, Impact, Damage, PFC2D
Numéro: 1
Volume: 5
Année: 2014
Texte
Sommaire: A methodology based on a two-stage approach was developed for process technology selection. The first stage includes evaluation of available technologies, followed by shortlisting the best technologies based on mass and energy balance modelling, financial analysis, and risk analysis. The second stage involves detailed analysis using refined input data, mass and energy balance modelling, and capital and operating cost estimation, as well as a more detailed financial analysis. A case study...
Publication: CIM Journal
Auteur(s): Y. Gordon and S. Kumar
Mots clés: Blast furnace ironmaking, Alternative ironmaking technology, Melting, Direct reduced iron (DRI), Hot briquetted iron (HBI), Iron nugget, Pig iron (PI), Technology selection, Risk analysis, Financial analysis
Numéro: 1
Volume: 5
Année: 2014
Texte
Sommaire: The mining limit in oil sands is regulated by the ratio of total mining volume (ore, interburden, and overburden) one has to mine per volume of bitumen in place (TV/BIP). This paper presents a mathematical solution for creating the most economical pit outline where the TV/BIP ratio upper limit is 12, by combining mining economic theory and the Lerchs-Grossmann (LG) algorithm.
Publication: CIM Journal
Auteur(s): L. Chunpongtong
Mots clés: Total volume to bitumen in place (TV/BIP)*, Pit limit, Lerchs-Grossmann (LG), Oil sands
Numéro: 1
Volume: 5
Année: 2014
Texte
Sommaire: Understanding process histories and worker exposures in nickel production operations is critical in determining the role nickel compounds play in respiratory cancer incidence. As part of a series on Vale Canada’s (previously known as Inco) nickel processing operations, this paper includes descriptions of Ni electrolytic operations at refineries in Port Colborne, Ontario (1922–1984), and Thompson, Manitoba (1961–present). Industrial hygiene measurements, by area and personal sampling, of...
Publication: CIM Journal
Auteur(s): B. R. Conard
Mots clés: Inco, Nickel, Electrorefining, Electrowinning, Electrolyte purification, Inhalation exposure
Numéro: 1
Volume: 5
Année: 2014
Texte
Sommaire: This paper evaluates the potential of freeze-thaw dewatering using Albian mature fine tailings (MFT). Freezing tests were first performed to study the effect of freezing rate on dewatering efficiency. Lower freezing rate resulted in higher thawed solids content and shear strength. Subsequently, large strain consolidation tests were conducted to investigate consolidation behaviour and how it is affected by freeze-thaw. The consolidation behaviour was presented in terms of effective stress...
Publication: CIM Journal
Auteur(s): Y. Zhang, D. C. Sego
Mots clés: Freeze-thaw, Dewatering, Oil sands tailings, Mature fine tailings (MFT), Large strain consolidation
Numéro: 1
Volume: 5
Année: 2014
Texte
Sommaire: In this paper, we used data collected from the Gibraltar mine to analyze the effect of the TyreSense tire monitoring system on tire performance by reducing tire wear and preventing premature tire failure or damage. We analyzed the relationship between tire temperature, tire pressure, and tire failure or damage to help better understand the importance of controlling high tire temperature and pressure. The results enhance and expand the knowledge of the management of tire operational pressure...
Publication: CIM Journal
Auteur(s): J. Zhou, R. A. Hall, S. Klingmann
Mots clés: Tire monitoring, Pressure and temperature alerts, Damage prevention, Wear reduction
Numéro: 1
Volume: 5
Année: 2014
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