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

目前在油砂工业中使用的水基沥青提取方法主要设计用于处理沥青含量相对高且细粒含量低的矿石。然而，存在大量的低品位高细粒矿石，其单独产生差的沥青回收率。这些贫矿石需要与高比例的高品位、低细粒的好矿石混合，以实现所需的提取性能。然而，在一些矿山，没有足够的好矿石用于混合。迫切需要一种解决方案，以便能够在没有或有限的矿石混合的情况下处理贫矿。为此，Syncrude Canada Ltd.开发了一种新技术，可显著提高沥青回收率，尤其是贫矿的回收率。这项专利技术的核心是使用氢氧化钠（苛性碱）作为主要加工助剂（PPA）和选定的化学品作为次要加工助剂（SPA）的协同作用。结果发现，苛性碱和柠檬酸钠作为SPA的组合使用不仅显著地改善沥青回收率和泡沫质量，而且还提高了沥青产率。本发明能够从阿尔伯塔油砂资源中回收更多的沥青。它已成功地在Syncrude实现了全面的商业应用。然而，关于SPA在沥青提取中为什么和如何起作用的基础科学仍然有待于研究。本研究旨在提高我们对沥青提取中二次加工助剂（SPA）的基本认识。拟议的研究计划将为油砂行业开发下一代二次加工助剂以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.