CFD Analysis of Venturi-Assisted Xanthate Transport and Tailings-Slurry Circulation in a Composite Conditioning Tank

Abstract

Inefficient xanthate transport and poorly defined circulation paths can limit the conditioning of low-grade lead–zinc tailings. A Venturi-assisted composite conditioning tank was therefore evaluated using ANSYS Fluent 2025 R2 (Ansys Inc., Canonsburg, PA, USA). The volume of fluid (VOF) model described the air–slurry free surface, the renormalization group (RNG) k–ε model and multiple reference frame (MRF) approach represented the impeller-induced mean flow, and a transient user-defined scalar (UDS) described the transport of a generic normalized xanthate tracer. The slurry phase was represented as a generic homogeneous equivalent medium rather than as a fully characterized solid–liquid suspension. The Venturi throat generated a local low-pressure region and stable reagent suction; at a tailings inlet velocity of 2.50 m·s−1, the reagent-branch inlet mass flow rate was 2.825 × 10−4 kg·s−1. Parameter comparisons identified 350 r·min−1, an impeller installation height of 370 mm, and an annular gap width of 60 mm as the preferred combination. The calculated impeller power increased from 0.211 kW at 200 r·min−1 to 2.304 kW at 400 r·min−1. Increasing the speed from 350 to 400 r·min−1 raised power consumption by 60.9% but average velocity by only 5.8%. Compared with a conventional tank, the composite tank formed a coherent impeller–lower connecting–annular upflow–upper recirculation pathway, providing more favorable hydrodynamic conditions for xanthate transport and potential reagent–particle contact.