Utilization of aromatic hydroxamates with different carbon chain lengths for pyrochlore, calcite, feldspar, and quartz flotation

Abstract

The implementation of a high-performance collector represents a promising strategy for enhancing mineral recovery. In this study, the flotation performance of hydroxamic acid was firstly investigated by examining the flotation behavior of pyrochlore, calcite, feldspar, and quartz using aromatic hydroxamates (AHA), namely methyl benzohydroxamic acid (MBHA), ethyl hydroxamic acid (EBHA), isopropylbenzohydroxamic acid (PBHA), and tert-butyl benzhydroxamic acid (TBHA). Furthermore, the adsorption mechanism of AHA on pyrochlore was elucidated through zeta-potential tests, contact angle measurements, and XPS analysis. Micro-flotation results demonstrated that AHA exhibited good collecting ability for pyrochlore, low to moderate collecting ability for calcite, but no collecting ability for feldspar and quartz. The comparision of collecting ability on pyrochlore and calcite of AHA was as follows: TBHA > PBHA > EBHA > MBHA. Contact angle experiments showed that after treatment with AHA, the contact angle was enlarged significantly for pyrochlore followed by calcite; however, it witnessed minimal changes in feldspar and quartz. Zeta potential and XPS data provided clear evidence for the chemical adsorption of AHA on pyrochlore surfaces. Understanding the structure-activity relationship and mechanism of AHA in the flotation process of pyrochlore, calcite, feldspar, and quartz will contribute to identifying appropriate collector selection and optimizing beneficiation process.