The Mechanism of Viscosity-Enhancing Admixture in Backfill Slurry and the Evolution of Its Rheological Properties

Abstract

Since filling slurry is a cement-based material, viscosity-enhancing admixture exerts a significant effect on its rheological performance and mechanical properties. Viscosity-enhancing admixture can improve pipeline transportation performance and reduce pipeline wear during the filling process of a kilometer-deep mine by changing the plastic viscosity and yield stress of high-concentration filling slurries. In order to reveal the influence mechanism of viscosity-enhancing admixture on rheological performance in slurry, the influence of viscosity-enhancing admixture on the rheological performance of slurry is explored by adjusting viscosity-enhancing admixture dosage and conducting bleeding test, liquidity test, and rheological performance test. The extended DLVO theory is employed to analyze the mechanism of HPMC on the stability of filling slurry. The results show that compared with ordinary slurry, after adding HPMC and XG, the particles of filling slurry are prone to link to form a mesh structure. Besides, the increasing frictional force between particles results in a significant decrease in the bleeding rate and liquidity of the slurry. Such an effect becomes more obvious with the increase of viscosity-enhancing admixture dosage. Meanwhile, the overall effect of HPMC molecules is better than that of XG molecules since HPMC can reduce inter-particle repulsion and facilitate particle aggregation. The optimal dosage is about 0.1%, at which time the yield stress of the filling slurry increases from 89.236 to 160.06 Pa, the plastic viscosity increases from 0.296 to 1.063 Pa·s, and the compressive strength increases from 2.58 to 3.59 MPa in 28 days. The study reveals the influence of viscosity-enhancing admixture on the rheological performance of filling slurry and its evolution characteristics, which provides theoretical support for the development of filling resistance and wear reduction technology.

The Effects of Hydroxypropyl Methyl Cellulose and Metakaolin on the Properties of Self-Compacting Solidified Soil Based on Abandoned Slurry

“…From the above figure, it is observable that the compressive strength of SCSS initially decreases and subsequently increases with the augmentation of HPMC dosage, this result is consistent with the findings reported in reference [ 37 ]. Notably, the strength attains its maximum at a dosage of 0.3%.…”

“…Specifically, the water seepage rate for HPMC–10 settled at 0.92% finally, while HPMC–20 was even lower at 0.63%. Upon further increased the HPMC content SCSS to 0.5%, the final water seepage rates for it with two types of molecular weights of HPMC were exceptionally low in values at 0.21% and 0.22%, this is similar to the findings reported by Yang et al [ 37 ]. These results clearly demonstrated that HPMC is highly effective in reducing the water seepage rate of SCSS.…”

“…At a dosage of 0.27%, cellulose exhibited remarkable thickening and water retention capabilities, with the water retention capacity increasing proportionally with molecular weight. Yang et al [ 37 ] examined the impact of HPMC on cement-based grout properties. Their findings revealed that HPMC enhanced the aggregation of grout particles, resulting in an increase in compressive strength from 2.58 to 3.59 MPa after 28 days.…”

Hybrid Effect of Basalt and Polyacrylonitrile Fibers on Physico-Mechanical Properties of Tailing Mortar

“…The minimum fluidity occurs in the B0.50P0.05 group, decreasing by 33.11%. The addition of BF and PANF increases the friction of tailings to promote the interlocking effect [46][47][48]. In addition, fibers also absorb some water to reduce the water film thickness (WFT) on the mortar matrix and thus further reduce the fluidity of tailing mortar [49].…”

Dry Stacking of Filtered Tailings for Large-Scale Production Rates over 100,000 Metric Tons per Day: Envisioning the Sustainable Future of Mine Tailings Storage Facilities

“…An increasingly popular green mining alternative for storing mine tailings is filling underground mines with mine tailings, which has been applied in different countries around the world [32][33][34]. A particular case to highlight is the experience acquired in Peru, the second largest producer of copper in the world, where the use of mine tailings inside underground mines is being used to avoid the generation of acid rock drainage (ARD), eliminate the emission of particulate matter and thus avoid socio-environmental impacts in hydrographic basins [35].…”