The pendulum swings

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Sommaire: Pilot plant testwork on autogenous and semi-autogenous grinding was conducted at the Centre des Recherches Minerales du Quebec (CRM) to investigate the effect of ball addition, solids concentration in the feed, specific energy consumption and feed size distribution.
A mathematical model that incorporates breakage and surface mechanisms of loss of mass was developed to predict load size distribution of autogenous and semi-autogeneous mills. An empirical model was used to predict product size...
Publication: CIM Bulletin
Auteur(s): Mary Goldman
Mots clés: Autogenous grinding, Semi-autogenous grinding, Abrasion, Breakage, Modelling.
Numéro: 946
Volume: 84
Année: 1991
Texte
Sommaire: It is well known that the classification system of volcanogenic massive sulphides (VMS) is based upon their metal content. This metal content, the result of hydrothermal solutions circulating within strata underlying the deposits, is generally thought to be related directly to two parameters: (1) the nature of the underlying stratigraphic sequence; and (2) the physico-chemical conditions that existed at the time of the hydrothermal event. Furthermore, these two parameters are, in turn,...
Publication: CIM Bulletin
Auteur(s): Jacques Trottier, Michel Gauthier
Mots clés: Exploration, Base Metal deposits, Eastern Townships.
Numéro: 946
Volume: 84
Année: 1991
Texte
Sommaire: A mineralogical and trace element analysis was performed on the Kiire historical slags in order to evaluate the possible recovery of copper and cobalt. Reflected light microscopy, electron microprobe and image analysis were combined to determine the Cu and Co distribution in the slag.
The results indicate that 81% of the total cobalt is chemically combined in thefayalite whereas only 3.4% is in the mechanically entrapped sulphides. The remainder being in hercynite and wustite. On the other...
Publication: CIM Bulletin
Auteur(s): Eric Pirard
Mots clés: Applied mineralogy, Cobalt, Slag, Image analysis.
Numéro: 946
Volume: 84
Année: 1991
Texte
Sommaire: Mathematically, the proposed formula is: "Human Effectiveness + Technological Improvement = Success in the Nineties".
A brief review is made of geology, level of technology, management and labour situations, and range of production costs in coal producing countries. This comparison shows keen competition for Canadian coals, especially from the People's Republic of China, South Africa and Australia. Domestic competition comes from nuclear energy, hydro-electric generation, natural...
Publication: CIM Bulletin
Auteur(s): George E. Davies, David M. Parkes
Mots clés: Coal mining, Production costs, Lignite, Sub-bituminous coal, Productivity comparisons.
Numéro: 946
Volume: 84
Année: 1991
Texte
Sommaire: sulphide (VMS) deposits. Geochemical, isotopic and geochronological studies show that the vestiges of lapetus in Newfoundland probably record a complex series of island arcs and back-arc basins that were marginal to, rather than part of, the main ocean basin of lapetus. The geochemical and isotopic data provide a means of characterizing the tectonic environment of individual volcanic sequences, and allow us to identify a number of distinct tectonic environments in which VMS deposition took...
Publication: CIM Bulletin
Auteur(s): H. Scott Swinden
Mots clés: Exploration, Volcanogenic massive sulphide deposits, Mineral deposits, Dunnage Zone, Newfoundland Appalachians.
Numéro: 946
Volume: 84
Année: 1991
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