Fundamental understanding of secondary processing aids in bitumen extraction from mined oil sands

目前油砂行业使用的水基沥青提取工艺主要用于处理沥青含量相对较高、细粒含量较低的矿石。然而，存在着大量的低品位高粉矿，仅此一项就产生了较差的沥青回收率。这些劣质矿石需要与高比例的高品位、低粉尘的好矿石混合，才能达到预期的提取性能。然而，在一些矿山，没有足够的优质矿石用于混合。迫切需要一种解决方案，以便能够在没有或仅有有限的矿石混合的情况下处理劣质矿石。为此，加拿大辛克鲁德有限公司开发了一项新技术，显著提高了沥青回收率，特别是对贫矿。这项专利技术的核心是使用氢氧化钠(苛性)的协同作用作为主要工艺助剂(PPA)和选定的化学品作为辅助工艺助剂(SPA)。结果表明，混合使用苛性碱和柠檬酸钠作为SPA，不仅显著提高了沥青回收率和泡沫质量，而且提高了沥青产率。本发明能够从艾伯塔省的油砂资源中回收更多的沥青。它已经在辛克鲁德成功地实现了全面的商业应用。然而，关于SPA在沥青提取中的作用原因和方式的基础科学仍有待研究。本研究旨在促进我们对沥青提取中二次加工助剂(SPA)的基本理解。提出的研究方案将为油砂行业开发下一代二次加工助剂，提高沥青提取性能提供科学指导。

The water based bitumen extraction processes currently being used in the oil sand industry were mainly designed to process ores that are relatively high in bitumen content and low in fines content. However, there exist a large amount of low-grade high-fines ores which alone yield poor bitumen recovery. These poor ores need to be blended with a high proportion of high-grade, low-fines good ores to achieve desired extraction performance. In some mines, however, there are not enough good ores for blending. A solution is urgently needed to enable the processing of poor ores without or with limited ore blending. To this end, Syncrude Canada Ltd. developed a new technology that significantly improves bitumen recovery, especially for poor ores. The core of this patented technology is to use the synergy of sodium hydroxide (caustic) as the primary process aid (PPA) and a selected chemical as the Secondary Process Aid (SPA). It was found that the combined use of caustic and sodium citrate as SPA not only significantly improved both bitumen recovery and froth quality, but also increased bitumen production rate. This invention enables more bitumen to be recovered from the Alberta oil sands resources. It has been successfully implemented at Syncrude for a full scale commercialapplication. However, the fundamental science regarding why and how the SPA works in bitumen extraction remains to be investigated.This proposed research is to advance our fundamental understanding of secondary processing aid (SPA) in bitumen extraction. The proposed research program will provide the scientific leadership to the oil sands industry for the development of next generation of secondary processing aid to improve the bitumen extraction performance.