Switchable selective collectors for flotation of engineered artificial minerals

人们越来越担心可靠和畅通无阻地获得铂、钯、钽、稀土元素等关键原材料，以及铜和锂等其他元素，这些元素在现代技术中发挥着重要作用。在支柱A和B项目中，优先方案SPP 2315处理炉渣形成问题，以将稀释元素浓缩为工程人造矿物(ENAM)。申请人的S提案位于项目支柱C中，因为其目标是通过与普尼卡石榴天然产物Punicine相关的新型可切换捕收剂来开发选择性成分依赖分离。Punicine衍生物的电荷可以通过pH从正电荷调整到负电荷。此外，暴露在日光下(&gt；5000勒克斯；3300-5300K)可逆地在水中产生氧化还原活性的持久自由基。库仑相互作用、氢键的形成、pi给体、pi受体和sigma给体的能力，对于络合和表面吸附非常重要，可以通过外部参数(如pH或光)可逆地调节，甚至可以打开和关闭。在模型反应中已经确定了对金属的显著可调选择性。在首次浮选试验中，通过将光照条件从“白天”改为“黑暗”(&lt；40勒克斯)，重要的工程人造矿物(ENAM)铝酸锂的回收率在pH 6-7时提高了60%。在这些有希望的初步结果的基础上，这项建议的目标是开发用于ENAM浮选的可切换捕收剂，同时研究浮选后从捕收剂中有效且往往有问题的颗粒释放。我们将在Punicine核心上安装已知的浮选活性官能团，使其可切换，即根据pH值和光线对目标EAM进行选择性，以便有效地从不需要的EAM或脉石材料中分离出来。目标ENAM颗粒含有锂、铜、钽、稀土元素和铂族元素。

There is growing concern about reliable and unhindered access to critical raw materials such as platinum, palladium, tantalum, rare-earth elements, but also other elements such as copper and lithium, which play important roles in modern technology. In the project pillars A and B, the priority programme SPP 2315 addresses slag formation to concentrate diluted elements as engineered artificial minerals (EnAMs). The applicant´s proposal is located in project pillar C as its goal is to develop selective composition-dependent separations by means of new and switchable collectors which are related to the natural product Punicine from Punica granatum. The charges of Punicine derivatives can be adjusted from positive to twofold negative by the pH. In addition, exposure to daylight (> 5000 lux; 3300–5300 K) reversibly gives persistent radicals in water which are redox active. Coulombic interactions, hydrogen bond formations, pi-donor, pi-acceptor and sigma-donor capabilities, important for complexation and adsorption on surfaces, can either be reversibly tuned by external parameters such as pH or light, or even switched “on” and “off”. Remarkable adjustable selectivities toward metals have been identified in model reactions. In first flotation experiments, the recovery rate of lithium aluminate, an important engineered artificial mineral (EnAM), increase at pH 6-7 by 60% simply by changing the light scenario from “daylight” to “darkness” (< 40 lux). On the basis of these promising preliminary results, the objective of this proposal is the development of switchable collectors for the flotation of EnAMs which goes in parallel with studies of effective and often problematic releases of the particles from the collectors after the flotation. We will install known flotation-active functional groups onto the Punicine core to make them switchable, i.e. selective toward target EnAMs depending on pH and light in order to allow effective separations from undesired EnAMs or gangue materials. Target EnAM particles contain lithium, copper, tantalum, rare-earth elements and those of the platinum group.