简介：卡尔加里Suncor能源公司开发出新技术，着力提升油砂尾矿的回收处理速度。尾矿是细粉状土泥土、沙子、水和残余沥青的混合物，通常堆放在一个大池子内等待回收处理。处理方法是首先抽吸池子底部的尾矿粉，加入聚合基凝聚剂，使之沉淀凝结成大块状，排出水分。固体物质主要用作建筑材料，而排出水则送回油砂处理厂重复利用。

Calgary-based Suncor Energy is moving forward with a new technology that promises significant improvement in the speed of reclamation of oil-sands tailings. Studies have been so promising with the technology, known as Tailings Reduction Operations (TRO), that the company has submitted a regulatory application in Canada to implement it at existing oil-sands operations near Fort McMurray.

“TRO is a significant advance in tailings management and reclamation,” said Kirk Bailey, executive vice president, Oil Sands, for Suncor. “We believe it will help us meet new provincial regulatory requirements and, just as importantly, the changing expectations of stakeholders.”

Tailings--a mixture of fine clay, sand, water, and residual bitumen produced through the oil-sands extraction process--are typically pumped into large man-made ponds for storage and reclamation. The extremely small size of the tailings--a particle is on average smaller than 40 μm in diameter--effectively keeps them in suspension, meaning that many decades must pass before the tailings have sufficiently separated from the water to become a more solid mass that can be reclaimed.

As oil-sands operations keep expanding, the long settling time has delayed surface reclamation and required Suncor to build more and larger tailings ponds--an option the producer wants to avoid.

Suncor’s TRO process is designed to significantly reduce the time required for reclamation of fine tailings such that the footprint of oil-sands operations is diminished. The process first calls for pumping mature fine tailings from the bottom of tailings ponds into a Suncor processing facility, where it is mixed with a polymer-based flocculant. This mixture is then pumped in thin layers onto sand beaches that have been landscaped with shallow slopes.

The fine clay tailings flocculate quickly into larger accumulations, which settle onto the beach and allow the separated water to drain away for collection. The resulting product is a dry material that can be reclaimed in placed or moved to another location. Suncor has used the reclaimed tailings as construction material, and the separated water has been recycled back into the oil sands processing facilities, thus reducing the amount of imported water.

The TRO process takes the drying process down from a hundred years or more to a few weeks, meaning that Suncor can reclaim the land behind their oil sands mining operations much faster. In addition to allowing for more progressive reclamation, the process will also allow Suncor to reduce their footprint, as fewer large ponds will be needed. The new process can also be used to reduce existing tailings inventory at Suncor’s operations.

The proposed implementation of the TRO process at Suncor facilities is subject to approval by the Energy Resources Conservation Board, Alberta Environment, and Suncor’s Board of Directors. Pending approvals, the company plans to begin rapidly accelerating the implementation of TRO to its facilities in 2010.

In the meantime, Suncor has been working closely with key stakeholders to ensure that they understand the new process and technology and to address any concerns they may have. This stakeholder engagement will continue through the regulatory review process.

“In 2010, Suncor plans to officially complete the reclamation of our first tailings pond to a solid surface,” said Bailey. “It’s fitting that in the same year we reach an important reclamation milestone, we expect to implement improved technology to increase the pace of reclamation. It’s all about continuous improvement in our environmental, social and economic performance.”