Polymers with Biobased Hydrophobic Cardanyl Acrylate and O-Ethyl Acetylcarbamothioate Functionality for Chalcopyrite Selective Flotation

The effective separation of chalcopyrite, an extensively utilized copper mineral, presents a considerable hurdle for the mineral processing sector due to its geological tendency to be colocated with various sulfide minerals and its intricate surface chemistry that hinders efficient separation using conventional approaches. This research aims to address this challenge by utilizing Reversible Addition-Fragmentation Chain Transfer polymerization (RAFT) as a synthetic methodology for preparation of collector/flocculants to enhance the efficiency and selectivity of reagents for utilization in chalcopyrite flotation/flocculation. A RAFT polymer, poly(CA₄-co-ACOEA₁₄), was synthesized incorporating O-ethyl acetylcarbamothioate (R-O-C(═S)-NH-C(═O)-CH₃) functionality for selective binding and cardanyl acrylate moiety as a hydrophobic component, with the goal of selective separation of chalcopyrite from pyrite. Laboratory experiments encompassing flotation/flocculation tests, adsorption assessments, and analyses utilizing UV spectroscopy, FTIR spectroscopy, X-ray photoelectron spectroscopy, and contact angle measurements were conducted to explore its performance in froth flotation and elucidate its adsorption mechanism on both mineral surfaces. A comparative study between poly(CA₄-co-ACOEA₁₄) and poly(CA₄-co-XEA₁₄), the latter is a polymer of similar molecular weight and hydrophobicity containing the xanthate functionality, demonstrated that poly(CA₄-co-ACOEA₁₄) exhibits superior performance. This enhanced efficacy could be attributed to the polymer’s capacity to selectively adhere to the chalcopyrite surface, rendering it hydrophobic, while a comparable effect is not observed on pyrite due to weak adsorption. Furthermore, the flocculation performance of poly(CA₄-co-ACOEA₁₄) showcases its dual functionality as both a collector and a flocculant.