The influence of slurry density on in situ density

摘要

Since the beginning of the Paste and Thickened Tailings seminar series, there has been ongoing discussion as to whether an increase in the deposited (initial) slurry density will result in an increased density at depth within an accreting deposit, all else being equal. Despite frequent speculation and theorising, there has been relatively little laboratory data or other evidence presented at the conference series to address this question.To address the above deficiency, a literature review was undertaken to identify experimental programs where the same material was prepared for soil testing from different initial slurry densities. Twelve such studies were identified, of which nine indicate that an increase in initial slurry density resulted in increased density at subsequent significant vertical effective stresses. Case studies presented on three tailings deposits are investigated, to assess the implications of the presented results on the potential for initial slurry density to influence in situ density. For many of the studies reviewed, there appears to be an indication that an increased initial slurry density resulted in an increased in situ density at significant vertical effective stresses. Finally, a series of consolidation tests were undertaken by the authors, wherein four tailings types were prepared from different non-segregating initial slurry densities. For three of these materials, a dependence on situ density was observed, based on changes to initial slurry density.On the basis of the review and experimental data presented in this study, the authors conclude that for at least some materials, initial slurry density can result in an increased density across a wide range of vertical effective stesses.