Abstract:
The hydroxamic acid reagents are extremely pervasive in the collector of scheelite flotation. Due to its high price and large dosage, the flotation cost of scheelite is high. To achieve cost−effective and efficient flotation of scheelite, this study proposes a ternary combined collector for scheelite flotation: benzohydroxamic acid (BHA)+R−benzoic acid (4−MBA)+octyl hydroxamic acid (OHA). The synergistic effect of the combined collector in the scheelite flotation system was confirmed by molecular dynamics simulation. Meanwhile, it was further verified that the combined collector has good collection performance for scheelite through actual ore flotation experiments. Molecular dynamics simulation results indicate that as the variety of collector increases, the relative concentration of water molecules on the scheelite (112) surface decreases, enhancing hydrophobicity. The lowest relative concentration of water molecules on the scheelite surface was observed under the ternary combined collector system. This suggests a synergistic effect among the ternary combined collectors, resulting in a stronger hydrophobicity on the mineral surface. The flotation test was conducted on a complex low−grade scheelite ore. The results showed that the addition of 4−MBA at a dosage of 11.11% in the BHA flotation scheelite system effectively improved the flotation effect of BHA on the scheelite ore, while reducing the BHA dosage by approximately 37.5% while ensuring the flotation recovery. When OHA at a dosage of 2.22% was combined with BHA, the flotation recovery of scheelite ore increased by about 20%, and the flotation foam layer was improved. The best flotation effect was exhibited under the ternary combination of BHA+OHA+4−MBA. Using water glass and carboxymethyl cellulose (CMC) as depressants, a closed−circuit flotation test consisting of roughing, scavenging, and three stages of cleaning can obtain scheelite concentrate with a WO
3 grade of 28.55% and a WO
3 recovery of 72.04%. Compared to using benzohydroxamic acid as a single collector on site, the grade and recovery of scheelite concentrate increased by approximately 3% and 4%, respectively, while reducing the collector dosage by 37.5%. Therefore, the ternary combined collector can significantly reduce the cost of flotation reagent while improving the recovery of scheelite, and realize the efficient recovery of scheelite.