Flocculation and dewatering of oil sands tailings with hyperbranched functional polyolefins

艾伯塔省的油砂储量是加拿大的主要自然资源。它们是世界第三大原油来源，仅次于沙特阿拉伯和委内瑞拉。不幸的是，加拿大人为使用这种宝贵的自然资源付出了高昂的环境代价。油砂行业采用的提炼工艺，每加工一桶沥青，就会产生约1.5桶液体细粒尾矿。尾矿是水、沙、粘土和残留沥青的混合物。尾矿被转移到沙子快速沉降的池塘中，但细小的粘土在发生显著沉降之前保持悬浮很长一段时间。经过多年，形成了含有30wt%左右细粒粘土的稳定悬浮液，称为成熟细粒尾矿。成熟的细粒尾矿具有酸奶的稠度。在这些池塘上行走或开车是不可能的。结果，他们占领的地区变成了一片无法恢复的荒地。据测算，到2020年，我国成熟细粒尾矿堆积量将超过10亿立方米。尾矿的持续收集在艾伯塔省造成了严重的环境问题，因为目前的处理技术无法显著减少遗留尾矿和新鲜尾矿的数量。

The oil sands reserves in Alberta are a major Canadian natural resource. They are the third largest source of crude oil in the world, only surpassed by those of Saudi Arabia and Venezuela. Unfortunately, Canadians pay a high environmental price to use this valuable natural resource. The extraction process adopted by the oil sands industry produces about 1.5 barrels of fluid fine tailings for every barrel of bitumen processed. Tailings are a mixture of water, sand, clays, and residual bitumen. The tailings are transferred to ponds where the sand settles fast, but the fine clays remain suspended for a long time before significant settling takes place. After many years, a stable suspension containing about 30 wt% of fine clays, called mature fine tailings, is formed. Mature fine tailings have the consistency of yogurt. It is not possible to walk or drive on top of these ponds. Consequently, the area they occupy becomes a wasteland that cannot be recovered. It has been estimated that the accumulated volume of mature fine tailings will exceed one billion cubic meters by 2020. The continuing collection of tailings has created a severe environmental problem in Alberta because the current treatment technologies cannot significantly reduce the volumes of legacy and fresh tailings.