Mineral Separation with Biological Macromolecules

先前的工作已经证明，7至12个氨基酸的肽选择性地结合到具有经济利益的矿物，如黄铜矿、硫砷铜矿和闪锌矿。有人建议，这可以作为选择性矿物分离计划的基础。最近的工作已经表明，用矿物质结合肽功能化的磁性纳米颗粒（有效地为磁性收集剂）可以用于在将功能化的纳米颗粒添加到混合物中后使用磁体从矿物质颗粒的合成混合物中分离感兴趣的超细（<38微米）矿物质颗粒。在此条件下，黄铜矿与石英的分离回收率达到80%，黄铜矿与硫砷铜矿的分离回收率达到65%。 需要更好地了解肽与矿物质的结合机制。光谱成像技术将被应用于表征的肽-矿物质结合，特别是要确定的极性氨基酸的作用，基于丙氨酸扫描的结合肽，是必要的结合。使用肽功能化的磁性纳米颗粒，SQUID磁力计将用于测量涂覆的矿物颗粒的磁响应，以使得能够正确确定纳米颗粒剂量。 第二个目的是扩大磁分离过程。在工业规模下，使用肽回收小矿物颗粒将需要肽和矿物颗粒之间的相互作用被限制在小体积例如小直径管中，这是一种过程强化的形式。用于混合浆料的具有磁性收集器的小直径特氟隆管的歧管可以提供廉价的可扩展的替代方案。 第三，由于定制肽制造是昂贵的，因此需要一种替代方案，以便在矿物分离中使用磁性收集器在经济上是可行的。 其他人最近的工作表明，有可能对简单的细菌（如大肠杆菌）进行遗传工程改造，在其细胞内结构内合成磁铁矿，并使其能够在其外膜上展示矿物质结合肽，从而简单地通过培养遗传工程改造的细菌来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。 该计划将推进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。 在遗传工程、微反应器设计和采矿业技术实施方面，HQP也有很多培训机会。

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.