Study on Correlations between Tailings Particle Size Distribution and Rheological Properties of Filling Slurries

Abstract

The influence of the mass concentration and particle size distribution on rheological parameters and slump was investigated by analyzing the mixture of overflow tailings (OT) and classified tailings (CT). The correlation between the rheological parameters, slump and characteristic value of the tailings particle diameter was discussed. Finally, the ratio parameters of a mixed tailings filling slurry were optimized using a lead–zinc mine in Guangdong, China as the engineering background. The results showed a quadratic decrease in the slump of the tailings slurry as the mass concentration increased, while the slump decreased with a decreasing particle size. With the increase in the mass concentration, the yield stress of the tailings slurry follows a quadratic function, while the plastic viscosity exhibits linear growth. The influence of tailings fine particles on the sensitivity of the yield stress and plastic viscosity to the mass concentration is reduced as their content increases. The yield stress and plastic viscosity of the tailings slurry exhibit a quadratic function decrease and linear growth as the slump increases. The slump of the tailings slurry is related to the particle size characteristic value and the mass concentration of the slurry. The correlation coefficient between the yield stress and the aggregate characteristic particle size increases most obviously at d10~d50, and the increase in the characteristic particle size will enhance the correlation between the yield stress and particle gradation. The correlation coefficient between the plastic viscosity and aggregate particle gradation parameters exhibits an initial increase followed by stabilization with an increasing characteristic particle size, with the most significant increase observed at d10~d50.

Numerical Study of Gangue Slurry Deposition Behavior in Pipelines Considering Viscosity Change

“…Before Figure 3 shows that the plastic viscosity of the gangue slurry becomes more significant with the increase in mass concentration. With the increase in the number of particles, the shear rate increases, and the gangue particles collide, resulting in a shear thickening phenomenon, and the viscosity of the slurry gradually increases [2,9,18]. At the same time, there is a concentration interval in which the viscosity growth rate is significant.…”

“…Coal gangue made into a gangue-based slurry that is used to fill mining holes can be a way to dispose of enormous amounts of waste gangue. It can effectively control the ground subsidence to achieve green mining [9,10]. The slurry filling must be transported from the ground to the stratum or hollow area through a pre-constructed pipeline.…”

“…Suppose that the viscosity of the slurry is too low. In that case, stratification and segregation can quickly occur and many particles settle, resulting in pipeline clogging in the slurry transportation process [9,11,20]. However, the research at this stage does not consider the influence of the viscosity change of the slurry on the rule of motion of the coal gangue slurry.…”