Nascimento Guilherme Randow, Bazan Selma Fabiana, de Lima Guilherme Ferreira
Grupo de pesquisa em Química Inorgânica Teórica - GPQIT, Departamento de Química, Universidade Federal de Minas Gerais, Brazil.
Laboratório de Química Computacional - LaQC, Instituto de Física e Química, Universidade Federal de Itajubá, Brazil.
Acta Crystallogr C Struct Chem. 2024 Sep 1;80(Pt 9):458-471. doi: 10.1107/S2053229624006867. Epub 2024 Aug 8.
Chalcopyrite, the world's primary copper ore mineral, is abundant in Latin America. Copper extraction offers significant economic and social benefits due to its strategic importance across various industries. However, the hydrometallurgical route, considered more environmentally friendly for processing low-grade chalcopyrite ores, remains challenging, as does its concentration by froth flotation. This limited understanding stems from the poorly understood structure and reactivity of chalcopyrite surfaces. This study reviews recent contributions using density functional theory (DFT) calculations with periodic boundary conditions and slab models to elucidate chalcopyrite surface properties. Our analysis reveals that reconstructed surfaces preferentially expose S atoms at the topmost layer. Furthermore, some studies report the formation of disulfide groups (S) on pristine sulfur-terminated surfaces, accompanied by the reduction of Fe to Fe, likely due to surface oxidation. Additionally, Fe sites are consistently identified as favourable adsorption locations for both oxygen (O) and water (HO) molecules. Finally, the potential of computer modelling for investigating collector-chalcopyrite surface interactions in the context of selective froth flotation is discussed, highlighting the need for further research in this area.
黄铜矿是世界主要的铜矿石矿物，在拉丁美洲储量丰富。由于铜在各个行业具有战略重要性，铜的提取带来了显著的经济和社会效益。然而，对于处理低品位黄铜矿矿石而言，被认为更环保的湿法冶金路线仍然具有挑战性，通过泡沫浮选对其进行富集也是如此。这种认识上的局限源于对黄铜矿表面结构和反应性的了解不足。本研究回顾了近期利用密度泛函理论（DFT）计算并结合周期性边界条件和平板模型来阐明黄铜矿表面性质的相关研究。我们的分析表明，重构表面优先在最顶层暴露硫原子。此外，一些研究报告称在原始硫终止表面上形成了二硫基团（S₂），同时铁还原为亚铁（Fe²⁺），这可能是由于表面氧化所致。另外，铁位点一直被确定为氧（O₂）和水分子（H₂O）的有利吸附位置。最后，讨论了在选择性泡沫浮选背景下利用计算机建模研究捕收剂 - 黄铜矿表面相互作用的潜力，强调了该领域进一步研究的必要性。
