Bauxite Mining and the Environment

背景

With a share of 8 %, aluminium is the third most abundant element in the earth’s crust. Thus, the availability of raw material supplies for the production of aluminium is almost unlimited.

生产oVerview

铝土矿是铝生产的常见原材料，主要由一种或多种氢氧化铝化合物组成，以及二氧化硅，铁和氧化二氧化硅，作为主要杂质。它用于通过拜耳化学过程and subsequently aluminium through theHall-Heroult electrolytic Process。在全球范围内，需要4至5吨铝土矿才能生产两吨氧化铝，从中可以生产一吨铝。在欧洲，通常铝土矿的平均消耗量为每吨铝的4.1吨。

Bauxite Production

每年开采超过1亿吨铝土矿。沉积物的主要位置在赤道周围的一条宽带中发现。铝土矿目前正在澳大利亚（每年超过4000万吨），中部和南美（牙买加，巴西，苏里南，委内瑞拉，圭亚那），非洲（几内亚），亚洲（印度，中国），俄罗斯，哈萨克斯坦和哈萨克斯坦和哈萨克斯坦和欧洲（希腊）。

The material is mainly extracted by open-cast mining, which has a variable and highly site-specific effect on the local environment. The primary ecological concerns connected to this operation are related to the clearing of vegetation, affect on local flora and fauna, and soil erosion.

表1. 1998年全球铝土矿产量的细分。

Bauxite M在森林地区

雨林的保护是铝土矿开采经常提出的关键问题。如今，世界上只有大约6％的铝土矿开采在雨林地区进行，影响总面积约为1.5公里。²per year. The total area of the globe currently covered by rain forest is about 18 million km²。

一旦停止采矿业务，就恢复了铝土矿开采的大部分土地的原始动植物。对于用于铝土矿开采的所有森林地区，80％的人返回原生森林，其余的则由农业，商业森林或休闲区取代，从而使该地区对当地社区的生产力更高。但是，尤其是雨林，雨林中用于铝土矿开采的区域几乎完全恢复回到雨林。

重生

During the preparation of a site for open-cast mining, the surface soil is removed to get access to the bauxite. In order to avoid soil erosion and to ensure that vegetation is returned to the land, many companies have water drainage practices during mining operations, separate removal of top soil (50 per cent reuse it directly after the mining operation) and over 60 per cent have their own nursery plant facilities. Rehabilitation plans are established prior to the start-up of operations and the investments required to implement these plans are built into mining costs.

铝业对环境的承诺的证明

Alcoa won for example in 1990 the United Nations Environmental Programmes “Global 500 Roll of Honour for Environmental Achievement” award for exemplary reforestation and recultivation of its bauxite mines in Western Australia. A computer-based system that integrates mining with environmental management was developed: the Geographical Information System (GIS). It helps engineers and scientists to produce accurate mine plans that consider biological diversity, land use value, and water quality.

铝制工业和土地开垦

诸如Alcan之类的公司已经开发了现在是巴西最成功的土地开垦项目之一，这要归功于员工教育，动植物的调查以及创建现场植物托儿所和种子收集计划。在950公顷的开采土地中，超过450多个已经完全恢复到森林中，其中120万次移植至少350种本地植被。

资料来源：欧洲铝协会。

For more information on this source please visitThe European Aluminium Association。