hdrocyclone separations are based on the response of an object ( a floc in our case ) to centrifugal forces in its surrounding medium. The behaviour of the floc is based upon its mass, which depends upon both the aggregate size (measured in this work)and density. Increasing size or density will cause an object to report to the underflow rather than the overflow. The density of a floc depends
upon its structure. Flocs with open structures will have a lower density than the same size floc with a compact structure. The fractal dimension of a floc is a measure of the structure. The fractal dimension of a floc is a measure of the structure of the floc. fractal dimensions can very from on to three. A floc with fractal dimension near one is very open while a floc with fractal dimension near three is quite compact. The density of the aggregate can be estimated from knowledge of the aggregate’s mass fractal dimension and size. An unusual consequence of the fractal nature of flocs is that they become less dense as they grow. The average volume fraction of solid particles within a floc decreases as the floc grows according to (bushel et al., 2002)
Where is the solids volume fraction, k is a structure prefactor assumed to be approximately one (Bushell etal.,2002), D the floc diameter, d the primary particle diameter and D is the fractal dimension.