Flow Properties Analysis and Identification of a Fly Ash-Waste Rock Mixed Backfilling Slurry

Abstract

The use of waste rock as an aggregate in mining backfill is environmentally friendly and cost-saving. The backfill slurry flow property varies with the change in aggregate, binder content, solid concentration, and additives. The slurry flow in a pipeline is governed by its properties, which makes it crucial to study the flow properties and their effects. One example is a fly ash-waste rock mixed slurry in Jinchuan Nickel, China. Tests on the slump, slump flow, mortar consistency, layering degree, and bleeding rate are performed to reveal the effects of the slurry concentration, binder content, and fly ash addition on the flow properties. Those relations are analyzed, and two new indices are derived (F1 and F2) using the principal component analysis method. Finally, the application results show that F1 > 0 indicates a nonhomogeneous flow; F1 < 0 and F2 > 0 indicates a high-density slurry flow; F1 < 0 and F2 < 0 indicates a paste slurry flow.

Study on Mix Proportion Optimization and Microstructure of Coal-Based Solid Waste (CSW) Backfill Material Based on Multi-Objective Decision-Making Model

“…Slump-flow and bleeding rate can measure fluidity to a certain extent, but the bleeding rate is more focused on measuring the water-retention performance of slurry. It can be seen from the literature [ 25 , 34 ] that, within the reasonable range of the bleeding rate in line with the paste backfill, the influence degree of the slump-flow on fluidity is higher than that of the bleeding rate, and the early strength should also be considered. Therefore, according to relevant literature and combined with relevant knowledge and experience, the order of importance of the impact on fluidity is slump-flow > bleeding rate > 3- day or 7-day strength, and the judgment matrix is constructed as follows: …”

Study on the effect of multi-source solid waste on the performance of its backfill slurry

“…Many scholars have done a lot of research work on the physical and mechanical properties of mine backfilling materials. Fall et al [ 11 ] took the uniaxial compressive strength, slump and solid concentration of cemented tails backfill as indicators, and proposed the mixture design method and performance prediction model of cemented tailings backfill; Zhang et al [ 12 ] obtained the optimal mix ratio of coal-based solid waste cemented filling through orthogonal experiments, and studied its mechanical properties and fluidity; Wei et al [ 13 ] studied the effects of slurry concentration, binder content and fly ash addition on the flow characteristics of backfill materials; Chen et al [ 14 ] optimized the fluidity and strength of gasified slag-based paste backfill materials by using the central composite experiment method, and analyzed the microscopic morphology; Koohestani et al [ 15 ] compared and studied the effects of different admixtures on the flow behavior, strength development and microstructure characteristics of cemented paste backfill composed of sulfide and non-sulfide. Tang et al [ 16 ] studied the mechanical properties and effects of each component before and after the mix proportion optimization of backfill material from coal-based solid waste; Cavusoglu et al [ 17 ] studied the effect of sodium silicate as an accelerator on the early mechanical and microstructure properties of cemented coal fly ash backfill; Zhao et al [ 18 ] explored the influence of loess content on the fluidity and mechanical properties of paste backfill materials; Jiang et al [ 19 ] studied the effects of aggregate gradation, sand addition and binder content on the uniaxial compressive strength and stress-strain characteristics of cemented rockfill.…”

The Release of Pollutants through the Bleeding of Cemented Phosphogypsum Backfill: Link to Protocols for Slurry Preparation

“…When the slurry is placed in the stopes, the free water gradually separates from the backfill slurry, accumulating as bleeding water [ 7 ]. Previous studies showed that the bleeding property is widespread in backfill slurry [ 8 , 9 ]. However, due to the use of solid waste as raw material, the bleeding water derived from the backfill slurry might contain large quantities of pollutants, thus threatening the surrounding environment.…”