Search

Flocculent settling widely exists in various processes of tailings disposal.It bears significance for the accurate calculation of the flocculent settling velocity in engineering, such as tailings backfilling and surface disposal.This paper studied the structural characteristics of tailings flocs from the perspective of the fractal theory, and established the mathematical relationship between tailings particle size, geometry size of floc and fractal dimension.It analyzed the influence of buoyancy effect, reflux effect and viscosity effect on floc settling, and deduced a calculation formula of tailings flocculent settling velocity.This study carried out a tailings flocculent settling test observed the changes in geometric morphology of flocs by focused beam reflectance measurement technology(FBRM), and carried out validation analysis between testing data and model calculation value.The results showed that the settling velocity increased with the equivalent grain size of flocs, which could be divided into three stages, namely accelerated settling, uniform settling and compaction settling.The equivalent grain size of flocs of test tailings were 140~350 μm, and the settling velocity calculated by the formula were 1.3~2.0 mm/s when the fractal dimension was 2.25, which demonstrates significant correlation with the testing value, and had certain practical application value.

Copyright of Transactions of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The drawback of the parameter estimation method for ARMA SαS process based on fractional lower order moments（FLOM） was analyzed,and based on the conception of fractional lower order covariance（FLOC）,a new parameter estimation method of ARMA SαS process was proposed based on FLOC coefficient.Then,the α-spectrum estimation of ARMA SαS process was presented.By estimating the α-spectrum of ARMA SαS process and the sinusoidal signals that embedded in the α-stable noise,the α-spectrum estimation performances of ARMA SαS process based on FLOM and FLOC were compared in detail.Simulation results show that,for small values of alpha,the performance of the proposed α-spectrum estimation method for ARMA SαS process based on FLOC provides better performance than the method based on FLOM.