Asynchronous flotation of scheelite, wolframite, and cassiterite: A new flotation collector and process

The collective enrichment of scheelite, wolframite, and cassiterite remains a significant challenge. This study investigates the distinct flotation behaviors of these minerals under Pb-BHA (lead complex of benzohydroxamic acid) through single-mineral flotation experiments. Quantum chemical analysis provides initial insights into the difference in their flotation rates based on their crystal structures. An asynchronous flotation process was designed to replace the synchronous process. And a new collector, Pb-MBHA (lead complex of P-methylbenzohydroxamic acid), was developed to enhance mineral recovery. The new process leverages the differential flotation kinetics of the three WSn minerals through the transition from a single- to dual-process, and employs stage-tailored pH conditions and flotation reagents to produce distinct concentrates. The new process and collector, implemented in a 1500 t/d concentrator, significantly increased the recovery rates of tungsten and tin. The recovery rate of WO₃ increased from 70 % to 78 %, while the recovery rate of Sn increased from 9 % to 22 %, generating an additional profit of $18,661.67/d. this research provides a very meaningful new approach to the comprehensive recovery of WSn minerals in complex WSn deposits