铝灰的处理技术、环境评价及相应管理政策

Treatment Technology,Environmental Evaluation and the Corresponding Management Policies of Aluminum Ash

铝灰是制铝工业生产过程中产生的有毒有害固体废弃物,一方面含有大量的金属铝及铝的化合物,具有较高的工业回收和再利用价值;另一方面常含有Cr、Cd、Pb等重金属元素和F^(-)、Cl^(-)、CN^(-)等有害离子,在污染土壤的同时,还会随着重金属元素和有害离子迁移导致地下水污染。随着我国2020年铝灰产量进一步上升,寻求经济绿色的铝灰回收方法、恰当的环境评价方法和合理可行的管理政策迫在眉睫。从铝灰处理方法、环境评价方法和铝灰管理政策3个方面总结了我国处理铝灰的方法、面临的难题和未来发展方向。现阶段而言,国内外铝灰处理方法主要分为铝灰回收、无害化处理和资源化利用,其中铝灰回收又分为火法回收和湿法回收。其中火法的无盐回收法,不引入盐类添加剂,污染较小、回收率较高,在未来有很大的应用空间;铝灰资源化是以铝灰为主要原料制备建材和药剂,由于材料成本较低、性能优越,对环境的污染少,因而具有广阔的应用市场和发展前景。环境评价方法则是以《土壤环境(试行)评价标准》(HJ 964—2018)和《地下水环境评价标准》(HJ 610—2016)为基础,结合多种统计方法给出包括环境变化趋势、承载上限等在内的评价结论,是具有实际意义的科学的评价方法。铝灰管理政策是从国家法规、地方政策和部分企业政策的角度出发,介绍了铝灰危害性和当前堆积管理政策,给企业未来政策制定提供了借鉴。总而言之,从铝灰处理、环境评价和管理政策不难看出,科研和生产势必要紧密结合,推动铝灰处理方法朝着绿色无毒、综合利用的方向前进。

Aluminum ash is a toxic and harmful solid waste produced in the production process of aluminum industry.On the one hand,it contains a large amount of metal aluminum and aluminum compounds,which has high industrial recovery and reuse value.On the other hand,it often contains heavy metals such as Cr,Cd,Pb and harmful ions such as F^(-),Cl^(-),CN^(-),which not only can pollute the soil,but also causes groundwater pollution with the migration of heavy metals and harmful ions.It is urgent to seek economic and green aluminum ash recovery methods,appropriate environmental assessment methods and both reasonable and feasible management policies with the further increase of aluminum ash output in China in 2020.The treatment methods,difficulties and future development direction of aluminum ash in China were summarized on three aspects,including treatment methods,environmental evaluation and management policies of aluminum ash.The treatment methods of aluminum ash are mainly divided into aluminum ash recovery,harmless treatment and resource utilization,among which aluminum ash recovery is divided into fire recovery and wet recovery currently.Among them,the salt-free recovery method of roasting method has a great application space in the future due to less pollution and higher recovery rate.The resource utilization of aluminum ash regards aluminum ash as the main raw material to obtain building materials and reagent.Because of the low cost of materials,superior performance and less pollution to the environment,it has a broad application market and development prospect.The environmental evaluation method is based on the Soil Environment(Trial) Evaluation Standard(HJ 964-2018) and Groundwater Environment Evaluation Standard(HJ 610-2016),and combines various statistical methods to give the evaluation conclusions including the trend of environmental change and the upper limit of bearing capacity,which is a scientific evaluation method with practical significance.Moreover,the hazard of aluminum ash and current management policy of stocking aluminum ash are introduced based on the national laws,local policies and some enterprise policies,which can provide reference for future policy formulation of enterprises.In a word,it is not difficult to see through the combination of aluminum ash treatment,environmental evaluation and management policy,scientific research and production will combine with each other closely to promote the aluminum ash treatment method towards the gradual green non-toxic and comprehensive utilization direction.