A Theoretical Model for the Rake Blockage Mitigation in Deep Cone Thickener: A Case Study of Lead‐Zinc Mine in China

Abstract

Deep cone thickener (DCT) is key equipment in cemented paste backfill (CPB) technology. However, rake blockage occurs frequently in DCT during the dewatering process of the unclassified tailings being thickened from dilute slurry to thickened tailings or paste. Rake blockage has disastrous effects on the CPB operation. In order to investigate the influencing factors of rake blockage in DCT, a mathematical model of rake power in DCT was developed. In addition, stacking mud bed (made of thickened tailings) from the DCT in Huize lead-zinc mine (HLZM) in different rake blockage accidents was sampled and tested to investigate the effect of tailings characters on rake blockage. Results indicated that the concentration of the mud bed and the friction between the mud bed and the cone wall contributed to the rake blockage. The concentration and friction were influenced by the high content of coarse particles in the mud bed. Moreover, activating devices for bed mud, as the corrective and preventive action, were developed to prevent the rake blockage, which was valid in HLZM.

The Recent Progress China Has Made in High-Concentration Backfill

“…The principle of flocculation sedimentation is used to condense fine particles into groups, which can reduce the diameter of thickener by more than 50%, reduce the area of occupation by about 20% and improve the processing capacity per unit area by several times. Highefficiency thickener has mature technology and wide application range, but there are also problems such as large footprint, small processing capacity and low concentration efficiency [30]. Figure 7c shows the inclined plate thickener, and Figure 7d shows the deep cone thickener.…”

Research on the Evaluation Modeling Method of User Experience Quality under Uncertain Noise Environment

“…Ruan et al [28] propose the weight distribution results of data quantity n in the range of 2-20 by using equations (1)- (5). Some results are as follows:…”

“…Among them, x σi sorts the data values in a descending order. Equations ( 22) and ( 23) ω i are obtained from the literature [28]. (4) Based on the weighted synthesis of probability density function of the normal distribution (WS-PDF-ND), equations ( 12)-( 15) were used to obtain the weight vector and perform an integration to get y 4 , respectively.…”