Effect of load variability on matching during continuous microwave treatment of crushed mineral ores

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dc.contributor.authorBradshaw S.M.
dc.contributor.authorMarchand R.
dc.date.accessioned2012-05-17T08:58:56Z
dc.date.available2012-05-17T08:58:56Z
dc.date.issued2012
dc.description.abstractIn order to assess the requirements for online matching when using a transverse electric field (E-field) applicator to treat mineral ores continuously, the effect of varying load properties on matching has been investigated by simulation. The effective permittivity of the ore to be treated is expected to show variation on both short (< 1 s) and long (minutes) time scales. By modelling the ore as a series of slices with alternating effective permittivity values, it was shown that permittivity variations on the scale of the expected particle size are attenuated significantly and matching is not required. For variations in permittivity on the length scale of the free-space wavelength, variations in reflected power are at most within ±10% of the mean. This is not considered operationally significant, as extreme permittivity variation over this length scale is unlikely, given the expected distribution of ore particle sizes to be treated. At typical ore transport speeds through the applicator, these variations occur on a time scale an order of magnitude shorter than the response time of typical industrial online matching equipment. This implies that online matching is neither required nor possible for short time scale variation. Long-term variations in dielectric properties can be adequately compensated for by current matching technologies. It is concluded that the transverse E-field applicator is robust to changes in the dielectric properties of crushed ores within the expected range of their variation. © 2011 The Southern African Institute of Mining and Metallurgy.
dc.identifier.citationSAIMM - Journal of The South African Institute of Mining and Metallurgy
dc.identifier.citation112
dc.identifier.citation1
dc.identifier.citation23
dc.identifier.citation29
dc.identifier.issn0038223X
dc.identifier.urihttp://hdl.handle.net/10019.1/21038
dc.subjectCurrent matching
dc.subjectE-field
dc.subjectEffective permittivity
dc.subjectFree-space wavelengths
dc.subjectLength scale
dc.subjectLong-term variations
dc.subjectMatching
dc.subjectMicrowave processing
dc.subjectMicrowave treatment
dc.subjectMineral ores
dc.subjectOn-line matching
dc.subjectOre transport
dc.subjectReflected power
dc.subjectShort time scale
dc.subjectTime-scales
dc.subjectTransverse electric field
dc.subjectVarying load
dc.subjectApplicators
dc.subjectElectric fields
dc.subjectOres
dc.subjectTime measurement
dc.subjectPermittivity
dc.titleEffect of load variability on matching during continuous microwave treatment of crushed mineral ores
dc.typeArticle
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