| 1. |
- Antti, Britt-Marie, et al.
(författare)
-
Pulp chemistry in calcite flotation. : Modelling of oleate adsorption using theoretical equilibrium calculations
- 1989
-
Ingår i: Mining engineering. - 0026-5187. ; 2:1, s. 93-109
-
Tidskriftsartikel (refereegranskat)abstract
- This paper considers the conditions required for direct flotation of calcite. Flotation experiments have been performed with oleate as the collector reagent and water glass as the dispersant and modifier. To be able to explain what happens in the flotation, solubility and adsorption experiments have been conducted parallel to, and under the same conditions as, the flotation experiments. Theoretical equilibrium calculations have been made with the help of data from the practical experiments for the purpose of modelling the adsorption experiments. With theoretical equilibrium calculations it is possible to predict that silicate ions will form complexes with calcium ions at the mineral surface.
|
|
| 2. |
- Antti, Britt-Marie, et al.
(författare)
-
Pulp chemistry in industrial mineral flotation. Studies of surface complex on calcite and apatite surfaces using FTIR spectroscopy
- 1989
-
Ingår i: Mining engineering. - : Elsevier BV. - 0026-5187. ; 2:2, s. 217-227
-
Tidskriftsartikel (refereegranskat)abstract
- Flotation experiments in a Hallimond tube have been performed on calcite and apatite at pH levels and oleate concentrations judged to be interesting from the point of view of adsorption isotherms. For the calcite system, adsorption isotherms indicate precipitation of calcium oleate after monolayer formation at pH 9, 10 and 11. In the apatite system, a double layer of oleate is formed. This means that apatite, unlike calcite, is sensitive to collector reagent overdosage. With the aid of FTIR techniques it is possible to demonstrate the existence of a surface complex in the apatite system with a calcium-oleate ratio of 1:1 at monolayer coverage of the surface. In conditions corresponding to bulk precipitation of calcium oleate, this compound can be detected by FTIR analysis of unfloated material.
|
|
| 3. |
- Banda, H., et al.
(författare)
-
Der Einfluss von Trübedichte, Körnung und Filtrationsdruck auf den Durchflusswiderstand eines Filterkuchens
- 1987
-
Ingår i: Aufbereitungstechnik - Mineral processing. - 0004-783X. ; 28:9, s. 513-520
-
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.
|
|
| 4. |
- Banda, H., et al.
(författare)
-
Porositätsvariationen bei auf horizontalen Flächen unter Druck geformten Filterkuchen
- 1988
-
Ingår i: Aufbereitungstechnik - Mineral processing. - 0004-783X. ; 29:1, s. 1-7
-
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.
|
|
| 5. |
- Banda, H., et al.
(författare)
-
Strukturanalyse eines Filterkuchens mit dem Bildanalysator
- 1987
-
Ingår i: Aufbereitungstechnik - Mineral processing. - 0004-783X. ; 28:4, s. 175-180
-
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.
|
|
| 6. |
- Banda, S.M.Herath, et al.
(författare)
-
Pressure filtration of a fine-grained chalcopyrite concentrate
- 1988
-
Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 17:2, s. 61-66
-
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.
|
|
| 7. |
- 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
-
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.
|
|
| 8. |
- Bengtsson, Margaretha, et al.
(författare)
-
The Importance Of Coal In Swedish Iron Production
- 1980
-
Ingår i: Jernkontorets annaler med Bergsmannen : JkA : tidskrift för nordisk bergshantering. - Stockholm : Jernkontoret. - 0348-6559. ; 164:3, s. 61-61
-
Tidskriftsartikel (refereegranskat)
|
|
| 9. |
- Berglund, Gun, et al.
(författare)
-
Influence of different gases in flotation of sulphide minerals
- 1989
-
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.
|
|
| 10. |
|
|
