A novel dissolution-precipitation method for high-efficiency separation of oil-wetted oil sands

Dissolution-precipitation is a novel high-efficiency method for separating oil-wetted oil sands. Four dissolving agents and three precipitating agents were studied to select the optimal combination. Results showed that N,N -dimethylcyclohexylamine (DMCHA) and methanol were the optimal dissolving and precipitating agents, respectively. The chemical group compositions, element content, and H/C atom ratio of bitumen separated by DMCHA-methanol were analyzed, and the optimal conditions for oil sands separation were determined, under which the bitumen recovery reached 96.4%. After six separation cycles with DMCHA-methanol, the bitumen recovery remained above 93%.