| Popis: |
A segregation index for vibrated binary mixtures, based on the concentration profile of the fines in a segregation cell, is proposed. Like Williams' segregation coefficient, it takes into account the overall composition of the mixture. Its major parameter, however, is the fines weight fraction at the very bottom and not in the bottom half of the cell. Computer simulations of various concentration profiles show that it is a more sensitive index, especially for segregating mixtures having a narrow concentration profile or a low fines concentration. This is because even when all or most of the smaller particles are found at the bottom half of the cell, their distribution is still taken into account. The index was developed for mixtures whose compressibility and density changes along the cell height can be ignored. For such mixtures, it suffices to measure the fines concentration at the very bottom in order to calculate the index without actually determining the whole concentration profile in the cell. Determination of the profile may still be advisable, however, in order to verify the assumptions on which the index calculation is based. |
