ASPIRE - Accelerated Supergene Processes in Repository Engineering

英国在集料、关键矿物和元素的未来供应方面面临严峻的战略挑战。与此同时，英国必须可持续地管理每年产生的数百万吨工业、采矿和矿产废物(IMMW)。预计未来几年产生的这些废物的数量将会增加，特别是(I)生物质和城市固体废物燃烧产生的灰烬，以及(Ii)受污染的疏浚工程。这些废物将继续被填埋，尽管这些废物往往含有宝贵的资源，如高浓度的关键金属、土壤常量营养素和有用的矿物成分，其中一些可以有效地吸收大气中的二氧化碳。ASPIRE(存储库工程中的加速表生过程)研究项目的基本目标是开发一种可持续的方法，通过这种方法可以去除灰烬、受污染的疏浚物和其他IMMW中任何有价值的元素。然后，这些剥离的元素将集中在矿区供以后回收，清理后的残留物也将返回使用，例如用作骨料、水泥添加剂或农业改良剂(包括通过加强矿物风化来固碳的改良剂)。设计一种真正可持续的方法来实现这一点在经济上是可行的，这是一个非常具有挑战性的问题，到目前为止，文献中提出的几乎所有浸出废物的过程本身都是碳和化学密集型的，因此是不可持续的。我们正在提出的研究包括开发“渴望废物资源库”概念的第一步，其中包括加速类似于工程中的成矿“表生”过程，从而使休眠废物经历以下过程：(I)将有价值的成分(例如关键金属、磷酸盐)浓缩为人为矿石，以促进其未来的回收。和(Ii)同时净化残留矿物材料，使其成为可用于农业、营林、绿地、新开发项目的美化、生境建设和/或作为水泥/混凝土添加剂或替代骨料的“软”用途的材料库。然后，被动员的元素将进入捕获区，在那里它们将从溶液中剥离并浓缩，形成人造矿石。该研究项目将寻求设计临时储存废物储存库的内部流程，以优化这一过程。与此同时，废物库的上层植被表面将作为绿地，为当地居民提供相应的生态和宜人的价值。其中关键的研究挑战是如何设计内部ASPIRE废物库过程，这依赖于复杂的生物地球化学相互作用和流动行为。另一项关键的研究挑战是发展对利益攸关方的理解和对这一概念的更广泛接受，因为这一概念不符合目前关于废物管理的立法。通过这个项目，我们寻求提供一个循环技术解决方案，在英国政府为过渡到循环经济制定战略和支持监管的关键时刻，我们如何可持续地管理未来数百万吨的IMMW。

The UK faces serious strategic challenges with the future supply of aggregates, critical minerals and elements. At the same time, the UK must sustainably manage multimillion tonne annual arisings of industrial, mining and mineral wastes (IMMWs). The amount of these wastes generated is projected to increase over the coming years, particularly (i) ash from the combustion of biomass and municipal solid waste, and (ii) contaminated dredgings. These wastes will continue to be landfilled despite often containing valuable resources such as high concentrations of critical metals, soil macronutrients and useful mineral components, some of which actively drawdown atmospheric CO2. The fundamental aim of the ASPIRE (Accelerated Supergene Processes In Repository Engineering) research project is to develop a sustainable method by which ashes, contaminated dredgings and other IMMWs can be stripped of any valuable elements. These stripped elements would then be concentrated in an ore zone for later retrieval and the cleaned residues also returned to use, for example as aggregates, cement additives, or agricultural amendments (including those for carbon sequestration through enhanced mineral weathering). It is a very challenging problem to devise a truly sustainable method to achieve this is an economically viable way, and almost all processes suggested so far in the literature for leaching wastes are themselves carbon and chemical intensive and thus non-sustainable.We are proposing research that comprises the first steps in developing the "ASPIRE waste repository" concept with accelerated analogues of ore-forming "supergene" processes engineered in, such that the dormant waste undergoes processes to (i) concentrate valuable components (e.g. critical metals, phosphate) as an anthropogenic ore to facilitate their future recovery, and (ii) concurrently decontaminate residual mineral material so as to make it available as a bank of material to drawdown for "soft" uses in agriculture, silviculture, greenspace, landscaping in new developments, habitat creation and/or as a cement/concrete additive or replacement aggregate.The processes investigated rely on rainwater passing through a vegetated surface layer which releases naturally occurring compounds from the plant roots and/or other natural organic matter which then pass through and strip valuable elements from the IMMW. The mobilised elements will then pass into a capture zone where they will be stripped from solution and concentrated to form an artificial ore. The research project will seek to engineer the internal processes of the temporary storage waste repository to optimise this. At the same time the upper vegetated surface of the waste repository will serve as greenspace with commensurate ecological and amenity value for local populations.Among the key research challenges is in how to engineer the internal ASPIRE waste repository processes which rely on complex biogeochemical interactions and flow behaviour. Another critical research challenge is to develop an understanding of stakeholder and wider acceptability of this concept which does not fit with current legislation on waste management. With this project we seek to provide a circular technology solution for how we can sustainably manage the future multimillion tonne arisings of IMMW at a critical time as the UK government develops strategies and supporting regulation for the transition to a circular economy.