Study on Solid Suspension Characteristics in a Laboratory-Scale Slurry Electrolysis Stirring Tank

Slurry electrolysis (SE) is a hydrometallurgical technology that offers notable advantages in the efficient extraction of metals from complex minerals while minimizing carbon emissions. This study aimed to investigate the characteristics of solid suspension within a 1:6 scaled cold water model, employing a combination of high-speed imaging and fiber probe measurements. The effects of stirring speed (N, 60–200 rpm), solid mass concentration (c, 175–357 g/L), liquid level height (H, 270–330 mm) on the clear liquid layer, axial and radial solid concentrations, and tank homogeneity were assessed. It was found that the flow was smooth at the solid–liquid interface, with the absence of significant vortexes formations at the center. On the horizontal plane, the distribution of solid concentration was observed to be uniform in the middle region, gradually increasing toward the edges. Notably, when the stirring speed reached N = 200 rpm, the tank achieved uniform suspension, which corresponds to a speed range of 33–52 rpm in the SE prototype. The relationship between stirring speed and solid concentration was analyzed, showing that the interaction between particles cannot be ignored. Furthermore, increasing the liquid level contributes to reducing fluctuation in the liquid surface, the tank exhibited the highest level of homogeneity when the liquid level height was set to H = 300 mm.

Graphical Abstract