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Impact of talc on pulp and froth properties in F150 and 1-pentanol frother systems / Seng How Kuan in Minerals engineering, Vol. 23 N° 11-13 (Octobre 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 11-13 (Octobre 2010) . - pp. 1003–1009 Titre : Impact of talc on pulp and froth properties in F150 and 1-pentanol frother systems Type de document : texte imprimé Auteurs : Seng How Kuan, Auteur ; James A. Finch, Auteur Année de publication : 2011 Article en page(s) : pp. 1003–1009 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Flotation  bubbles  Flotation  frothers  Flotation  froths Résumé : The role of frother controlling bubble size and froth properties is reasonably well understood in the air–water system. A concern is how well this relates to the three-phase flotation condition. As a model hydrophobic solid talc was used. A column was run at fixed froth depth and air rate with overflow and underflow recycled. Four frothers were examined, two polyglycols, polypropylene glycol (F150), polypropylene methyl ether (DF250), and two alcohols, 1-heptanol and 1-pentanol. At steady state, pulp zone gas holdup and bubble size were measured along with water and solids overflow rate as a function of talc addition. For 1-heptanol and DF250 there was no impact of talc on bubble size or gas holdup. For 1-pentanol the presence of talc had no effect on bubble size but gas holdup increased; in contrast, for F150 addition of talc increased bubble size and decreased gas holdup. There was a reversal in water overflow rate between the F150 and 1-pentanol on adding talc, the 5:1 ratio in favour of F150 in air–water becoming 3:1 in favour of 1-pentanol at 5 wt% talc. The solids overflow rate likewise favoured 1-pentanol in presence of talc. The increase in bubble size in the talc/F150 system implies coalescence, as further evidenced by the bubble size distribution becoming bi-modal. The mechanism proposed was a combination of talc adsorbing frother from solution, demonstrated by TOC analysis of residual frother, and directly from the bubble surface due to the orientation of adsorbed F150. In the talc/pentanol case the increase in gas holdup was attributed to bubbles not being at terminal velocity and attached talc particles increasing deceleration, i.e., slowing bubble rise. The increase in water overflow rate in the talc/pentanol system corresponds to increased froth stability imparted by hydrophobic solids. Froth stabilization by talc with F150, however, is offset by the increased bubble size that means less water is carried into the froth. The reversal in water overflow ranking of the frothers can, therefore, be interpreted as due to frother/solid interactions. Similar interactions may account for reversals noted in other systems. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001184 [article] Impact of talc on pulp and froth properties in F150 and 1-pentanol frother systems [texte imprimé] / Seng How Kuan, Auteur ; James A. Finch, Auteur . - 2011 . - pp. 1003–1009. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 11-13 (Octobre 2010) . - pp. 1003–1009 Mots-clés : Flotation  bubbles  Flotation  frothers  Flotation  froths Résumé : The role of frother controlling bubble size and froth properties is reasonably well understood in the air–water system. A concern is how well this relates to the three-phase flotation condition. As a model hydrophobic solid talc was used. A column was run at fixed froth depth and air rate with overflow and underflow recycled. Four frothers were examined, two polyglycols, polypropylene glycol (F150), polypropylene methyl ether (DF250), and two alcohols, 1-heptanol and 1-pentanol. At steady state, pulp zone gas holdup and bubble size were measured along with water and solids overflow rate as a function of talc addition. For 1-heptanol and DF250 there was no impact of talc on bubble size or gas holdup. For 1-pentanol the presence of talc had no effect on bubble size but gas holdup increased; in contrast, for F150 addition of talc increased bubble size and decreased gas holdup. There was a reversal in water overflow rate between the F150 and 1-pentanol on adding talc, the 5:1 ratio in favour of F150 in air–water becoming 3:1 in favour of 1-pentanol at 5 wt% talc. The solids overflow rate likewise favoured 1-pentanol in presence of talc. The increase in bubble size in the talc/F150 system implies coalescence, as further evidenced by the bubble size distribution becoming bi-modal. The mechanism proposed was a combination of talc adsorbing frother from solution, demonstrated by TOC analysis of residual frother, and directly from the bubble surface due to the orientation of adsorbed F150. In the talc/pentanol case the increase in gas holdup was attributed to bubbles not being at terminal velocity and attached talc particles increasing deceleration, i.e., slowing bubble rise. The increase in water overflow rate in the talc/pentanol system corresponds to increased froth stability imparted by hydrophobic solids. Froth stabilization by talc with F150, however, is offset by the increased bubble size that means less water is carried into the froth. The reversal in water overflow ranking of the frothers can, therefore, be interpreted as due to frother/solid interactions. Similar interactions may account for reversals noted in other systems. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001184

Possible role of hydrogen sulphide gas in self-heating of pyrrhotite-rich materials / Stéphanie Somot in Minerals engineering, Vol. 23 N° 2 (Janvier 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 2 (Janvier 2010) . - pp. 104-110 Titre : Possible role of hydrogen sulphide gas in self-heating of pyrrhotite-rich materials Type de document : texte imprimé Auteurs : Stéphanie Somot, Auteur ; James A. Finch, Auteur Article en page(s) : pp. 104-110 Note générale : Génie Minier Métallurgie Langues : Anglais (eng) Mots-clés : Environmental  Sulphide  ores  Self-heating  Hydrogen  sulphide  Non-ferrous  metallic  ores  Tailings  Oxidation  Reduction Index. décimale : 622 Industrie minière Résumé : Self-heating of sulphides poses safety, environmental and economic concerns to the mining and metallurgical industries, especially when sulphide ores or concentrates have to be stored or transported. The first target of this investigation is the self-heating of pyrrhotite (Po), the most commonly suspected mineral to trigger the phenomenon because of its fast oxidation in moist air. Following a standard experimental protocol, self-heating was assessed on samples of Po mixed with sand as an inert material. With increasing Po content, self-heating rates progressively increased but the samples visually appeared less and less oxidized. A high Po content, it was hypothesized, may give a more reducing environment favouring formation of hydrogen sulphide (H2S). The presence of this gas could be significant for self-heating for several reasons which are discussed. The hypothesis was tested by including copper pieces to detect the gas by forming copper sulphide, and adding copper sulphate in excess which suppressed self-heating, apparently by reacting with and removing the gas. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VDR-4XDKC9K-1&_user=6 [...] [article] Possible role of hydrogen sulphide gas in self-heating of pyrrhotite-rich materials [texte imprimé] / Stéphanie Somot, Auteur ; James A. Finch, Auteur . - pp. 104-110. Génie Minier Métallurgie Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 2 (Janvier 2010) . - pp. 104-110 Mots-clés : Environmental  Sulphide  ores  Self-heating  Hydrogen  sulphide  Non-ferrous  metallic  ores  Tailings  Oxidation  Reduction Index. décimale : 622 Industrie minière Résumé : Self-heating of sulphides poses safety, environmental and economic concerns to the mining and metallurgical industries, especially when sulphide ores or concentrates have to be stored or transported. The first target of this investigation is the self-heating of pyrrhotite (Po), the most commonly suspected mineral to trigger the phenomenon because of its fast oxidation in moist air. Following a standard experimental protocol, self-heating was assessed on samples of Po mixed with sand as an inert material. With increasing Po content, self-heating rates progressively increased but the samples visually appeared less and less oxidized. A high Po content, it was hypothesized, may give a more reducing environment favouring formation of hydrogen sulphide (H2S). The presence of this gas could be significant for self-heating for several reasons which are discussed. The hypothesis was tested by including copper pieces to detect the gas by forming copper sulphide, and adding copper sulphate in excess which suppressed self-heating, apparently by reacting with and removing the gas. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VDR-4XDKC9K-1&_user=6 [...]

Quantifying the content of gravity recoverable platinum group minerals in ore samples / Z. Xiao in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 304–310 Titre : Quantifying the content of gravity recoverable platinum group minerals in ore samples Type de document : texte imprimé Auteurs : Z. Xiao, Auteur ; André R. Laplante, Auteur ; James A. Finch, Auteur Année de publication : 2009 Article en page(s) : pp. 304–310 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gravity  recovery  Platinum  group  minerals Index. décimale : 622 Industrie minière Résumé : A protocol for predicting recovery of platinum group minerals (GRPGM) is adapted from the protocol for gravity recoverable gold. This paper introduces the methodology to characterize the content of GRPGM in samples using the 3-in. (7.5 cm) laboratory Knelson concentrator. Results for two ore samples are presented, as well as some mineralogical analysis of the gravity concentrates. The methodology can also be used for sample preconcentration to aid mineralogical analysis. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002082 [article] Quantifying the content of gravity recoverable platinum group minerals in ore samples [texte imprimé] / Z. Xiao, Auteur ; André R. Laplante, Auteur ; James A. Finch, Auteur . - 2009 . - pp. 304–310. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 304–310 Mots-clés : Gravity  recovery  Platinum  group  minerals Index. décimale : 622 Industrie minière Résumé : A protocol for predicting recovery of platinum group minerals (GRPGM) is adapted from the protocol for gravity recoverable gold. This paper introduces the methodology to characterize the content of GRPGM in samples using the 3-in. (7.5 cm) laboratory Knelson concentrator. Results for two ore samples are presented, as well as some mineralogical analysis of the gravity concentrates. The methodology can also be used for sample preconcentration to aid mineralogical analysis. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002082