| 1. |
- 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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| 2. |
- Pugh, R.J., et al.
(författare)
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The influence of magnetic and surface forces on the coagulation of hematite and chromite
- 1994
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Ingår i: Minerals & metallurgical processing. - 0747-9182. ; 11:3, s. 133-140
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Tidskriftsartikel (refereegranskat)abstract
- The coagulation of dispersed ultrafine weakly magnetic oxide mineral particles (e.g., natural hematite and chromite) in an external magnetic field can be described by interparticle forces. Essentially, coagulation occurs when the short-range London-van der Waals interactions and the long-range magnetic forces outweigh the stabilizing electrical double-layer repulsion. Using the classical colloid chemistry theory, the various components of the potential energy for different-sized particles at a series of ionic strengths and magnetic field intensities were calculated.
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| 3. |
- Wang, Yanmin, et al.
(författare)
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Carrier coagulation of chromite fines in wet magnetic separation
- 1993
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Ingår i: Magnetic and Electrical Separation. - : Hindawi Limited. - 1055-6915 .- 1029-0303 .- 1477-2876. ; 5:1, s. 33-52
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Tidskriftsartikel (refereegranskat)abstract
- A 'carrier' or 'piggy-back' coagulation process was applied to improve the separation efficiency of chromite slimes in wet high-gradient magnetic separation. This was achieved by the addition of a coarse chromite fraction to the slime fraction (< 10 mm). Three coarse chromite fractions were investigated in the present study with size ranges 75, 53 and 38 μm. The results suggested that the 38 μm coarse fraction was the most effective in improving the process efficiency. Superior performance was also found to occur between pH 5 and 6. The results were discussed by computing the various components for potential energy of interaction between the slime particles and the 'carrier' or 'piggy-back' particles at a range of surface potentials in the absence or presence of the magnetic field.
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| 4. |
- Wang, Yanmin, et al.
(författare)
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Influence of interparticle surface forces on the coagulation of weakly magnetic mineral ultrafines in a magnetic field
- 1994
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Ingår i: Colloids and Surfaces A. - : Elsevier BV. - 0927-7757 .- 1873-4359. ; 90:2, s. 117-133
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Tidskriftsartikel (refereegranskat)abstract
- The paper demonstrates that the coagulation of dispersions of weakly magnetic mineral ultrafines in an external magnetic field can be described theoretically by invoking interparticle forces. This was done with the use of experimental results that relate the coagulation process to particle size, slurry pH and the external magnetic field. Coagulation were seen to occur either on the primary minimum or secondary minimum depending on the exerted magnetic force.
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| 5. |
- Wang, Yanmin, et al.
(författare)
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Influence of pH on the high gradient magnetic separation of
- 1992
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Ingår i: International Journal of Mineral Processing. - : Elsevier BV. - 0301-7516 .- 1879-3525. ; 36:1, s. 93-105
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the influence of surface interaction on wet high gradient magnetic separation (WHGMS) for hematite and quartz particles (<10 μm), by controlling the pH value of the slurry flow. This influence is discussed by computing the net interaction energies for the particle-particle and particle-matrix element systems at various pH values. Such an approach leads to an improvement in the efficiency of separating the mineral ultrafines by WHGMS.
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