Novo Separador E Classificador Magnético: Aplicações Em Processamento De Minérios

Abstract

Trabalho apresentado no XXI ENTMME, Natal-RN, novembro, 2005 RESUMO Os métodos convencionais de separação magnética, separam as partículas desviando-as da corrente principal ou coleccionando-as em matrizes. No entanto nenhum deste métodos convencionais apresenta a característica de classificar as partículas enquanto elas são separadas. O novo separador-classificador magnético desenvolvido, para além da apresentação de um novo processo de separação, preenche esta lacuna. Este processo de separação-classificação é conseguido através de uma geometria inovadora aplicada a uma configuração também ela inovadora. É feita uma breve análise dos separadores magnéticos actualmente mais utilizados na indústria e seus resultados genéricos em termos de classificação de partículas magnéticas.O novo separador-classificador é apresentado e os seus princípios de operação descritos. São destacadas duas principais aplicações do novo separador-classificador: a separação e classificação de materiais paramagnéticos com a mesma natureza (constituição química) mas com diferentes graus de pureza, e a separação-classificação de materiais paramagnéticos segundo a sua natureza (constituição química). São ainda discutidas outras aplicações práticas possíveis para o novo separador-classificador magnético. PALAVRAS-CHAVE: separação magnética; classificação magnética; processamento de minérios, materiais paramagnéticos.

Influence of the processing variables on the performance of MAGCLA™: friction coefficient and radius of the particles

“…Previous works [7,8,11,15] describe the new apparatus' working principles. Only a very brief description will be given here.…”

“…During their fall, these latter particles will suffer the influence of an increasingly stronger magnetic field, which will increase the strength of the magnetic forces, while the other forces will remain comparatively constant or with a very low increase/decrease. As this magnetic force depends upon the magnetic susceptibility of the particles, at the same radius, the magnetic particles with higher magnetic susceptibilities will feel a higher magnetic force than the other ones, and therefore the magnetic particles will depart towards the centre at different heights according to their magnetic susceptibility (see [8,14]). Three different collecting systems collect the particles: a top collector used to assemble the diamagnetic particles and the paramagnetic particles presenting very low magnetic susceptibilities, a central collector that gathers the particles according to their magnetic susceptibilities (classification) and a bottom collector which retains the particles presenting low magnetic susceptibilities (separated at the feeding point but which do not present high enough magnetic susceptibility in order to be classified during their descent).…”

“…In this paper, for each processing variable under study, we only present the final results obtained for the values considered for the processing variable in question. Detailed partial results may be found in [8].…”

“…A new magnetic separator and classifier, named magneticclassifier (MAGCLA TM ) [5,6], was developed, which is able to achieve a differential magnetic classification of magnetic particles (i.e. separation of the particles by classes of magnetic susceptibility [7,8]), therefore surpassing the limitations presented by the current industrial magnetic separators, which are only able to split the feed into few outcome streams [7][8][9]. A large-scale prototype of the device is being currently constructed for testing [10].…”

“…A large-scale prototype of the device is being currently constructed for testing [10]. Detailed descriptions of the new apparatus' working principles and its design can be found in [5,6,8,[11][12][13] and its supporting theory-concerning the equations of movement, modelling and limiting conditions of operation-is described in previous works [11,[14][15][16], regarding its application to minerals processing for dry mode and rotating trunk operation.…”