| 11. |
- Ayyala, S, et al.
(författare)
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Effect of corrosion inhibitors on grinding and flotation of a lead-zinc ore
- 1993
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Ingår i: Minerals Engineering. - 0892-6875 .- 1872-9444. ; 6, s. 929-935
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Tidskriftsartikel (refereegranskat)abstract
- Grinding and flotation experiments on a Pb-Zn ore were carried out to evaluate : 1) wear of the grinding media both in the presence and absence of an inhibitor and 2) effect of the inhibitor on the flotation of Pb-Zn minerals. The percentage reduction in the wear of the grinding media was observed to be between 25-36%, depending on the type of the inhibitor and its critical concentration. The inhibitors used in the investigation were sodium sulphite, sodium nitrite, sodium chromate and sodium silicate. The results indicate that a specific corrosion inhibitor, for example sodium sulphite, may give better recoveries and grades in flotation but is not as efficient as sodium chromate in inhibiting the wear of the grinding media. Pulp solutions (after grinding) analysed for metal ion concentrations showed low Fe. Iron released into the solution as a result of corrosion reactions subsequently forms insoluble hydroxy complexes and may coat the mineral surfaces. Such hydrophilic coatings may adversely affect the floatabilities of minerals. The particle size analysis of the ground product has been carried out and the results are discussed.
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| 12. |
- Banda, H., et al.
(författare)
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Der Einfluss von Trübedichte, Körnung und Filtrationsdruck auf den Durchflusswiderstand eines Filterkuchens
- 1987
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Ingår i: Aufbereitungstechnik - Mineral processing. - 0004-783X. ; 28:9, s. 513-520
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Tidskriftsartikel (refereegranskat)abstract
- The effects of slurry concentration, filtration pressure and particle size distribution on the resistance of a filter cake are studied, and an attempt is made to examine the filtration process with reference to the structure of the filter cake. Micrographic analysis clearly demonstrates the effect of particles segregation on filtration rate. The resistance of the cake rises with increasing solids concentration of the slurry, mainly due to a lower degree of particle segregation.
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| 13. |
- Banda, H., et al.
(författare)
-
Porositätsvariationen bei auf horizontalen Flächen unter Druck geformten Filterkuchen
- 1988
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Ingår i: Aufbereitungstechnik - Mineral processing. - 0004-783X. ; 29:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Direct measurement of the porosity variation in filter cakes by image analysis has been tested on chalcopyrite and magnetite slurries. It was found to give more accurate results than previous indirect methods, especially at the surface of the cake. Microscopy and image analysis visualize the effect of particle size, particle segregation and air bubbles on cake porosity. In a filter cake formed under constant pressure, the maximum porosity is shown to occur in regions inside the cake, rather than on the surface.
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| 14. |
- Banda, H., et al.
(författare)
-
Strukturanalyse eines Filterkuchens mit dem Bildanalysator
- 1987
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Ingår i: Aufbereitungstechnik - Mineral processing. - 0004-783X. ; 28:4, s. 175-180
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Tidskriftsartikel (refereegranskat)abstract
- Two methods for the consolidation of filter cakes are developed; one of them is based on acrylate plastic as an impregnating medium, and the other uses epoxy resin and is suitable for sulfide-carrying materials, where the first one fails. Even cakes formed from fine particles ( less than 38 mu m) can be consolidated using these methods. Specimens prepared with acrylate offer no difficulties in grinding and polishing; those prepared with epoxy resin, however, call for procedures with bonded grinding media, and the sections are preferably examined under a scanning electron microscope. Direct comparison between the consolidation methods has not been made. Porosity and pore size distribution are measured in filter cakes formed from two different materials using a computerized image analyzer.
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| 15. |
- Banda, S.M.Herath, et al.
(författare)
-
Pressure filtration of a fine-grained chalcopyrite concentrate
- 1988
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Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 17:2, s. 61-66
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Tidskriftsartikel (refereegranskat)abstract
- How material properties, cake characteristics and operating parameters affect the filtration rate and the final moisture content was investigated by laboratory test with a concentrate from a complex sulfide ore. Porosity and pore size distribution were measured by automatic image analysis. With optimum conditions, a moisture content of 5. 5% was achieved. A copper/lead concentrate floated from a complex sulfide ore at the Stekenjokk concentrator of Boliden Mineral AB, Sweden was used.
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| 16. |
- Banda, S.M.Herath, et al.
(författare)
-
Structure variation in filter cakes from flocculated slurries
- 1988
-
Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 17:2, s. 57-60
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Tidskriftsartikel (refereegranskat)abstract
- To flocculate slimy material dispersed in water is a common operation in mineral processing either to recover the material or to clear the water. In laboratory tests with flocculated slurries, floc sizes, porosity and sizes of filter cakes were measured by automatic image analysis. An observed decrease in filtrate flow rate at flocculant overdosage was not caused by a smaller mean floc size but may have been due to an obstruction of the pore channels by adsorbed polymer threads. Samples of a copper/lead concentrate floated at the Stekenjokk concentrator of Boliden Mineral AB, Sweden, were used for this investigation.
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| 17. |
- Banda, S.M.Herath, et al.
(författare)
-
Variation of filter cake permeability with mean pore diameter of the cake
- 1998
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Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 17:2, s. 67-72
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Tidskriftsartikel (refereegranskat)abstract
- It is shown that most particles in a filter cake have more than only point contact with each other. Therefore, the Kozeny-Carmen equation is modified by relating permeability to porosity and a mean pore diameter as measured by automatic image analysis in horizontal cross sections of the cake. In filter cakes of chalcopyrite and magnetite, the permeability increases stepwise with the product of porosity and square mean pore diameter.
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| 18. |
- Bengtsson, Margaretha, et al.
(författare)
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The Importance Of Coal In Swedish Iron Production
- 1980
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Ingår i: Jernkontorets annaler med Bergsmannen : JkA : tidskrift för nordisk bergshantering. - Stockholm : Jernkontoret. - 0348-6559. ; 164:3, s. 61-61
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Tidskriftsartikel (refereegranskat)
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| 19. |
- Berglund, Gun, et al.
(författare)
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Influence of different gases in flotation of sulphide minerals
- 1989
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Ingår i: Advances in Coal and Mineral Processing Using Flotation. - Littleton, Colo : Society for Mining, Metalurgy and Exploration. - 0873350871 ; , s. 71-76
-
Konferensbidrag (refereegranskat)abstract
- Sulfide mineral flotation is known to be affected by oxidation-reduction conditions in the pulp, although there is some doubt as to whether it is the oxidizing environment or the type of oxidant which influences flotation. Variations in the oxidizing conditions of the pulp and their subsequent effect on flotation were examined for two types of natural sulphide ore, a galena-sphalerite ore and a complex pyrite ore. Different gas mixtures ranging from pure nitrogen to pure oxygen were used to control the oxidizing conditions. Zinc recovery increased with a more oxidizing environment, and nitrogen gas acted almost as a depressant for sphalerite in the flotation of the Pb-Zn ore. For the complex pyrite ore, the selectivity between chalcopyrite and both gangue and pyrite improved when the environment was oxidizing, resulting in higher Cu recovery in the copper rougher concentrate.
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| 20. |
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