Wehr J Bernhard, Fulton Ian, Menzies Neal W
School of Land and Food Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia.
Environ Manage. 2006 Mar;37(3):297-306. doi: 10.1007/s00267-004-0385-2.
Alumina extraction from bauxite ore with strong alkali produces waste bauxite refinery residue consisting of residue sand and red mud. The amount and composition of refinery residue depend on the purity of the bauxite ore and extraction conditions, and differs between refineries. The refinery residue is usually stored in engineered disposal areas that eventually have to be revegetated. This is challenging because of the alkaline and sodic nature of the residue. At Alcan Gove's bauxite refinery in Gove, Northern Territory, Australia, research into revegetation of bauxite residue has been conducted since the mid-1970s. In this review, we discuss approaches taken by Alcan Gove to achieve revegetation outcomes (soil capping of refinery residue) on wet-slurry disposal areas. Problems encountered in the past include poor drainage and water logging during the wet season, and salt scalding and capillary rise during the dry season. The amount of available water in the soil capping is the most important determinant of vegetation survival in the seasonally dry climate. Vegetation cover was found to prevent deterioration of the soil cover by minimising capillary rise of alkalinity from the refinery residue. The sodicity and alkalinity of the residue in old impoundments has diminished slightly over the 25 years since it was deposited. However, development of a blocky structure in red mud, presumably due to desiccation, allows root penetration, thereby supplying additional water to salt and alkali-tolerant plant species. This has led to the establishment of an ecosystem that approaches a native woodland.
用强碱从铝土矿中提取氧化铝会产生由残渣砂和赤泥组成的铝土矿精炼废渣。精炼废渣的数量和成分取决于铝土矿的纯度和提取条件，不同的精炼厂之间存在差异。精炼废渣通常储存在最终需要进行植被恢复的工程处理区域。由于废渣具有碱性和钠质特性，这具有挑战性。在澳大利亚北领地戈夫的加拿大铝业公司戈夫铝土矿精炼厂，自20世纪70年代中期以来一直在进行铝土矿废渣植被恢复的研究。在本综述中，我们讨论了加拿大铝业公司戈夫为在湿浆处理区域实现植被恢复成果（对精炼废渣进行土壤覆盖）所采取的方法。过去遇到的问题包括雨季排水不畅和积水，以及旱季盐渍化和毛细上升。在季节性干旱气候中，土壤覆盖层中有效水分的含量是植被存活的最重要决定因素。人们发现植被覆盖通过最大限度减少精炼废渣中碱的毛细上升来防止土壤覆盖层恶化。自废渣沉积后的25年里，旧尾矿库中废渣的钠质和碱性略有降低。然而，赤泥中块状结构的形成，可能是由于干燥作用，使得根系能够穿透，从而为耐盐碱植物物种提供额外的水分。这导致了一个接近原生林地的生态系统的建立。
