The destruction time of the sediment column structure was measured for different fractions of silica particles in NaCl and CaCl2 solutions whose concentrations were varied from 0.25 M to 2.0 M. A linear relationship between the reciprocal of the destruction time of the silica sediment column structure and average diameter of the silica fraction, the density and work of cohesion of the solutions was found. The determined values of the particle diameter, the cohesion work and density of the solution calculated from these linear dependences for the time equal to infinity (1/t = 0) were named critical. Using the above critical parameters the detachment force of one particle from another was calculated. For the system whose components had critical values the detachment force was found to be equal to the attachment force resulting from the interfacial interaction. On the basis of our earlier study and Derjaguin's approximation the radius of the contact plane and the attachment force between two silica particles were calculated. The detachment force decreased with increasing salt concentration, but the attachment force was nearly constant. It was found that for a given salt concentration the relationship of the reciprocal of the destruction time as a function of the difference between the detachment and attachment forces was also linear. It appeared that for the silica column structure having critical parameters the values of the difference between the detachment and attachment forces were negative. This means that in the calculation of the attachment force between silica particles in the studied solutions an additional interaction should be taken into account.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.