A Combined Theoretical and Experimental Framework for Shifting to Greener Reagents in Mineral Processing

矿物加工使用了许多有毒或危险的试剂，这些试剂在工作场所对健康产生不利影响，并在尾矿库中处理后污染环境。废水和卫生法规的逐步收紧预示着，为了保持其社会许可证，该行业将被迫用更环保的替代品取代有毒试剂。为了满足这一需求，重要的是开发更环保的可再生替代品来替代传统的表面活性剂（例如浮选中的捕收剂和调节剂）。***目前开发新的浮选表面活性剂的策略是反复试验，这是昂贵和艰巨的，而预测工具箱由一般规则组成，如软硬酸碱规则，静电相互作用的pH控制和表面识别。然而，即使在通用水平上，可再生表面活性剂的预测规则也没有出现，这些可再生表面活性剂与传统表面活性剂不同，具有多个吸附基团和结构异构体的较大头基。另一种计算方法，如密度功能理论（DFT），也非常具有挑战性，因为它在捕获矿物-溶液界面和模拟真实矿物颗粒的不同结构和组成缺陷方面存在局限性，并且需要对大量可再生表面活性剂的头群进行数千种吸附结构的不切实际的筛选。***为了加速将可再生表面活性剂引入浮选实践，我建议开发并测试一种基于描述符的方法，该方法可以预测矿物表面对可再生表面活性剂的亲和力。采用吸附能之间的标度关系可以进一步降低计算成本。2007年引入尺度关系是催化剂计算设计发展的决定性一步。然而，这种先进的方法尚未用于浮选药剂的筛选。理论预测将进一步使用光谱、界面和浮选技术进行测试和修正。***主要的实际成果是a)对环境影响较小的矿物工业的更清洁的矿石加工技术，b)在石油和天然气回收等其他工业中使用可再生表面活性剂的指导方针。拟议的跨学科研究将培养下一代高素质的高级研究和工程方法人才，不仅在矿产行业，而且在石油和天然气、化学、油漆和颜料以及消费者护理行业，都需要促进可持续发展

Mineral processing utilizes many toxic or hazardous reagents which have adverse health effects in the workplace and pollute the environment after disposal in tailing ponds. The progressive tightening of wastewater and health regulations portends a future where the industry, to preserve its social license, will be forced to replace the toxic reagents by the greener alternatives. To meet this need, it is important to develop greener renewable alternatives to the conventional surfactants (e.g. collectors and regulators in flotation).***The current strategy for the development of new flotation surfactants is trial and error, which is costly and arduous, while the prediction toolbox consists of generic rules such as the soft hard acid base rule, pH control of the electrostatic interactions, and surface recognition. However, even at a generic level, predictive rules have not emerged for renewable surfactants which differ from the conventional counterparts by bulkier headgroups with multiple adsorption moieties and structural isomers. An alternative computational approach, such as density functional theory (DFT), is also very challenging given its limitations to capture the mineral-solution interface and computational cost to model different structural and compositional defects of real-world mineral particles, which entails impractical screening of thousand adsorption structures for a large set of headgroups of renewable surfactants.***To accelerate the introduction of renewable surfactants to flotation practices, I propose to develop and test a descriptor-based approach that allows predicting the affinity of mineral surfaces to the renewable surfactants. The computational cost will further be reduced by employing scaling relations between the adsorption energies of adsorbates. The introduction of scaling relations in 2007 was a decisive step in evolving the computational design of catalysts. However, this advanced approach has not been used for screening flotation reagents as yet. The theoretical predictions will further be tested and corrected using spectroscopic, interfacial, and flotation techniques.***The major practical outcomes are a) cleaner ore processing technologies for mineral industry with less impact on the environment, b) guidelines for employing renewable surfactants in other industries such as oil and gas recovery. The proposed interdisciplinary research will train the next generation of highly qualified personnel in the advanced research and engineering approaches required to advance sustainability not only in mineral industries but also in oil and gas, chemical, paints and pigments, and consumer care industries.**