Market asssessment: design and synthesis of well-defined ligands for selective extraction of precious metals (with initial emphasis on gold)

我们正在开发的技术涉及到从碱性氰化物溶液中选择性地提取金的新型配体的设计。氰化法是从矿石中提取和回收金的主要工艺。目前的技术包括使用大量的活性碳从溶液中提取金作为二氰基月桂酸酯(I)。然后，通过进一步添加碱性氰化钠溶液从活性碳中去除二氰基金酸酯(I)络合物，然后通过电积将其还原为单元金。在提取步骤中使用大量氰化钠仍然存在极大的争议，并引起极大的环境关注。在整个提取过程中，活性炭法也是最昂贵的步骤。我们将通过使用对二氰基月桂酸酯(I)具有高度选择性的配体来完全消除这一过程，然后通过现有的溶剂萃取技术来去除生成的络合物。然后，该配体将被回收用于额外的提取。在黄金生产的工业化生产中，还没有一种溶剂萃取系统被成功地实施。

The technology we that we are developing involves the design of novel ligands for selective extraction of gold from alkaline cyanide solutions. The cyanidation process is the dominant technique for extraction and recovery of gold from ore. Current technologies involve use of large amounts of activated carbon to extract the gold from solution as dicyanoaurate(I). The dicyanoaurate(I) complex is then removed from the activated carbon by further addition of a basic sodium cyanide solution and then reduced to elemental gold by electrowinning. The use of large amounts of sodium cyanide in the extraction step remains extremely controversial and is of great environmental concern. The activated carbon process is also the most expensive step in the whole extraction process. We will eliminate this process completely by using ligands that are highly selective for dicyanoaurate(I), following which the resulting complex can be removed by established solvent extraction technologies. The ligand would then be recycled for additional extractions. No solvent extraction system has ever been successfully implemented in the industrialization of gold production.