Mineral Separation with Biological Macromolecules

先前的研究表明，7到12个氨基酸的肽选择性地与具有经济价值的矿物结合，如黄铜矿、铝辉石和闪锌矿。有人认为，这可能是选择性矿物分离方案的基础。最近的研究表明，与矿物结合肽功能化的磁性纳米颗粒，实际上是一种磁性收集器，一旦将功能化的纳米颗粒添加到混合物中，就可以使用磁铁将超细（<38微米）矿物颗粒从合成的矿物颗粒混合物中分离出来。在超细颗粒混合物中，黄铜矿从石英中分离，回收率为80%，黄铜矿从辉石中分离，回收率为65%。******需要更好地了解肽与矿物质的结合机制。光谱成像技术将用于描述肽-矿物结合的特征，特别是确定极性氨基酸的作用，基于结合肽的丙氨酸扫描，极性氨基酸是结合所必需的。利用肽功能化的磁性纳米颗粒，将使用SQUID磁力计测量包覆的矿物颗粒的磁响应，以便正确确定纳米颗粒的剂量。******第二个目标是扩大磁分离过程的规模。在工业规模上，使用肽来回收小矿物颗粒将要求肽和矿物颗粒之间的相互作用被限制在小体积内，如小直径管，这是过程强化的一种形式。用于混合浆料与磁性收集器的小直径聚四氟乙烯管的歧管可以提供一种廉价的可扩展的替代方案。******第三，由于定制肽制造是昂贵的，需要一种替代方案，以便在矿物分离中使用磁性捕收剂在经济上可行。其他人最近的研究表明，通过基因工程改造简单的细菌，如大肠杆菌，可能在其细胞内结构中合成磁铁矿，并使它们能够在其外膜上显示矿物结合肽，从而通过培养基因工程细菌提供天然的磁性收集器。类似的基因工程也可以用酵母来完成。将对这些可能性进行调查。******该计划将推动矿物分离技术的发展，并为更好地回收和分离所需矿物提供几种替代方案。此外，在基因工程、微反应器设计和采矿行业的技术实施方面，HQP培训也有很多机会。*****************

Previous work has demonstrated that peptides of 7 to 12 amino acids selectively bind to minerals of economic interest such as chalcopyrite, enargite, and sphalerite. It was suggested that this could be the basis of a selective mineral separation scheme. More recent work has shown that magnetic nanoparticles functionalized with mineral binding peptides, effectively a magnetic collector, could be used to separate ultra-fine (<38 microns) mineral particles of interest from a synthetic mixture of mineral particles using a magnet once the functionalized nanoparticles were added to the mixture. Separation of chalcopyrite from quartz in mixtures of ultra-fine particles was achieved with 80% recovery and separation of chalcopyrite from enargite was achieved with 65% recovery. ******A better understanding of the peptide binding mechanism to minerals is needed. Spectroscopic imaging techniques will be applied to characterize the peptide-mineral binding, particularly to determine the role of polar amino acids which, based on alanine scans of the binding peptides, are necessary for binding. Using peptide-functionalized magnetic nanoparticles a SQUID magnetometer will be used to measure the magnetic response of the coated mineral particles to enable the correct determination of the nanoparticle dose.******A second objective is to scale up the magnetic separation process. At industrial scale the use of peptides to recover small mineral particles will require that the interaction between the peptides and the mineral particles be confined to a small volume such as a small diameter tube, a form of process intensification. A manifold of small diameter Teflon tubes for mixing slurry with magnetic collectors may provide an inexpensive scalable alternative. ******Thirdly, since custom peptide manufacture is expensive, an alternative is needed in order for the use of magnetic collectors in mineral separation to be economically viable. Recent work by others has shown that it may be possible to genetically engineer simple bacteria such as E coli, to both synthesize magnetite within their intracellular structures and to enable them to display mineral binding peptides on their outer membranes, thus providing a natural magnetic collector simply by growing the genetically engineered bacteria. Similar genetic engineering can also be done with yeast. These possibilities will be investigated. ******This program will advance the state of the art of mineral separation and provide several alternatives for better recovery and separation of desired minerals. Also there are many opportunities for HQP training in genetic engineering, micro-reactor design, and technology implementation in the mining industry. *****************