In situ recovery of resources from waste repositories

历史上，人类社会将大量的工业、市政、冶金和采矿废物排入地下，并将大量有价值的材料，如金属和能源（以生物质和聚合物的形式）等资源放入地质储存中。因此，不应将这些废物储存库视为遗留废物问题和长期责任，而应转变思维模式，将这些设施视为未来回收的“资源中心”。拟议的研究旨在促进与从现有废物储存库中回收资源有关的一个新的令人兴奋的研究领域的发展，并寻求解决以下中心问题：资源，特别是有价值的元素（如Au、Pd、Ag、Cu、Pb、Zn、Co、Ni、Sn和Cr）、用于清洁能源和其他环境应用的“E-tech”元素（如钕和其他稀土元素）和能源（通过增强甲烷生成），是否可以在材料处于原位时通过浸出和其他处理来回收，从而避免主动开采材料，从而最大限度地减少生态和环境影响？支撑这一点的基本地球科学研究问题是：我们如何理解和操纵地质储存库中废物的原位生物地球化学，以回收资源？这项研究的基本原理是研究资源回收的新技术，这些技术对环境的影响比主动（“挖掘和加工”）开采废物或原始矿石的环境影响小。就地浸出的概念和技术是在采矿业中为回收铀和铜而发展起来的，它是通过循环溶液提取元素和/或刺激和加强微生物浸出来完成的。以前没有充分讨论将这一概念应用于从废物储存库中回收资源的可能性。废物显示出不同的组成、矿物学和质地，与矿石非常不同，因此需要新的科学来理解和开发浸出方法，以溶解有价值的成分。我们将考虑从目前英国废物储存库中的各种废物中提取资源，包括工业和商业废物（预计富含金属）、焚化炉和燃料灰、矿物废物和城市废物，以研究就地浸出的想法。我们特别希望在拨款期间确定哪些类型的堆填废物流的某些资源可能相对丰富，并把研究重点放在从这些废物中回收废物上，以此作为起点。我们设想，就地浸出可以避免许多阻碍实现废物储存库资源潜力的问题，不仅在英国，而且在国际上产生重要影响。此外，我们的目标不仅是研究通过就地浸出回收资源的方法，而且还研究如何在生命周期方面适当地对这种过程（我们预计这种过程对环境和人类健康的影响可能要小得多）进行基准测试。将人类健康和生态系统服务成本以及公众舆论与通过“传统”挖掘和加工垃圾填埋采矿回收垃圾填埋资源和对相同资源进行常规采矿进行比较。其目的是提供证据，证明这些技术不仅在技术上是可行的，而且与传统技术相比影响较小，为利益攸关方所接受，因此是今后管理废物的可行和适当的办法。

Having historically disposed of vast quantities of industrial, municipal, metallurgical and mining waste into the ground, societies have put into geological storage an enormous amount of resources in a range of materials of value such as metals and energy (in the form of biomass and polymers). Therefore, instead of considering these waste repositories to be a legacy waste issue and a long-term liability, a paradigm shift is required to view these installations as "resource hubs" for future recovery. The proposed research aims to contribute towards the development of a new and exciting research field related to resource recovery from existing waste repositories and seeks to address the following central question: Can resources, specifically elements of value (e.g. Au, Pd, Ag, Cu, Pb, Zn, Co, Ni, Sn and Cr), 'E-tech' elements used in clean energy and other environmental applications (e.g. neodymium and other rare earth elements) and energy (through enhanced methane generation) be recovered by leaching and other treatments whilst the material lies in situ, thus avoiding the need to actively mine the material and thereby minimising ecological and environmental impacts?The fundamental geoscience research question that underpins this is:How can we understand and manipulate the in situ biogeochemistry of the waste within the geological repository to recover resource?The rationale behind the research is to examine new technologies for resource recovery with a lower environmental impact than active ('dig and process') mining of wastes, or of virgin ores.The concept and technology of in situ leaching has been developed in the mining industry for recovery of uranium and copper, and is done by circulating solutions to extract the elements and/or stimulating and enhancing microbial leaching. The possibility of transferring this concept for application to recovery of resource from waste repositories has not been fully addressed previously. Wastes display diverse compositions, mineralogies and textures very different to that of ores and thus will require new science to understand and develop leaching methods to solubilise valuable components.We will consider resource extraction from the full range of wastes currently in UK waste repositories including industrial and commercial waste (anticipated to be metal-rich), incinerator and fuel ash, mineral wastes and municipal wastes to examine the idea of in situ leaching. We are particularly keen to identify during the grant which types of landfilled waste streams might be relatively enriched in certain resources and focus the research on recovery from these wastes as a starting point. We envisage that in situ leaching could sidestep many of the problems that prevent realisation of the resource potential of waste repositories, with important impacts not only in the UK but internationally. Furthermore, our aim is to not only investigate means to recover resource through in situ leaching but to also investigate how we can appropriately benchmark such processes (which we anticipate may have substantially lower environmental and human health impacts) in terms of life-cycle, human health and ecosystems service costs as well as public opinion for comparison to retrieval of landfilled resources by 'conventional' dig-and-process landfill mining and against conventional mining of the same resources. This aims to provide evidence to demonstrate not only that the techniques are technically feasible but that they offer reduced impact compared to conventional technologies, are acceptable to stakeholders and thus are a feasible and appropriate approach to future management of wastes.