Xu Shaomei, Lu Xiangyu, Dai Zhifei, Li Shuai, Xiao Gang, Huai Yangyang
Jiangxi Copper Technology Institute Co., Ltd., Nanchang 330096, China.
ACS Omega. 2024 Aug 26;9(36):38088-38095. doi: 10.1021/acsomega.4c05225. eCollection 2024 Sep 10.
Chalcopyrite is a primary source of copper in nature. However, with the increasing need to process low-grade and complex chalcopyrite ores, overly stable froth is becoming more and more common and poses operational and safety challenges. No reliable strategy has been developed to address the issue. As a new initiative, this study investigated three different structured surfactants, sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and pentadecafluorooctanoic acid (PFOA), which vary in hydrophobic group, aiming to modify the surfaces of ultrafine chalcopyrite particles and adjust the interfacial tension at the gas-liquid interface to eliminate stable ultrafine chalcopyrite froth. The fundamental hypothesis was that an ideal surfactant structure could adjust the particle surface wettability and interfacial tension to eliminate overly stable froth. Based on contact angle measurements and interfacial tension measurements using a Theta Flow tensiometer by the pendant drop method and the sessile drop method, it was demonstrated that the contact angle played a dominant role in defoaming, while the reduction of gas-liquid interfacial tension had an adverse effect. Additionally, defoaming tests indicated that SDBS had lower defoaming effectiveness than SDS at low surfactant concentrations due to the steric hindrance in its structure, whereas the addition of SDBS could achieve a froth reduction efficiency as high as 93.75% at higher surfactant concentrations due to its stronger hydrophobicity and adsorption capacity to chalcopyrite particles, which could reduce the contact angle from 70 to 37.62°. However, PFOA exhibited lower defoaming effectiveness than both SDS and SDBS due to its lipophobic fluorocarbon tail of PFOA and weaker adsorption capacity to chalcopyrite particles, making it unsuitable for eliminating stable ultrafine chalcopyrite froth.
黄铜矿是自然界中铜的主要来源。然而，随着处理低品位复杂黄铜矿矿石的需求不断增加，过度稳定的泡沫越来越普遍，给操作和安全带来了挑战。目前尚未开发出可靠的策略来解决这一问题。作为一项新举措，本研究调查了三种不同结构的表面活性剂，即十二烷基硫酸钠（SDS）、十二烷基苯磺酸钠（SDBS）和十五氟辛酸（PFOA），它们的疏水基团不同，旨在改变超细黄铜矿颗粒的表面性质，并调节气液界面的界面张力，以消除稳定的超细黄铜矿泡沫。基本假设是，理想的表面活性剂结构可以调节颗粒表面润湿性和界面张力，以消除过度稳定的泡沫。通过悬滴法和座滴法使用Theta Flow张力仪进行接触角测量和界面张力测量，结果表明接触角在消泡过程中起主导作用，而气液界面张力的降低则产生不利影响。此外，消泡试验表明，由于SDBS结构中的空间位阻，在低表面活性剂浓度下，其消泡效果低于SDS；而在较高表面活性剂浓度下，由于其较强的疏水性和对黄铜矿颗粒的吸附能力，添加SDBS可实现高达93.75%的泡沫减少效率，这可以将接触角从70°降低到37.62°。然而，由于PFOA的疏氟碳链尾部以及对黄铜矿颗粒的吸附能力较弱，PFOA的消泡效果低于SDS和SDBS，使其不适用于消除稳定的超细黄铜矿泡沫。
