In situ recovery of resources from waste repositories

Lead Research Organisation: Cardiff University
Department Name: Sch of Engineering


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.

Planned Impact

We feel strongly that this research has real potential to actually kick-start a truly new discipline - in situ recovery of resources from waste repositories. The project is likely to have numerous social, economic and environmental impacts affecting a range of players in the waste recovery sector, as well as on residential communities and wider society in the future. Based on the model of impact defined by the RCUK, our work will contribute to both academic, and economic and societal impact. As a measure of our Academic Impact, we anticipate developing a new branch of technology - in situ recovery of resource from waste repositories and delivering and training highly skilled researchers. As a measure of our economic and societal impact, we will i) contribute towards evidence-based policy-making and influencing public policies and legislation at a local and regional level through our project partners and ii) contribute towards resource recovery, environmental sustainability, protection and impact reduction. The project's immediate impacts will be felt mainly through the generation and dissemination of new knowledge on the potential to recover resources from a range of wastes in situ. In the medium and longer term the project could have significant and wide-reaching benefits for a number of stakeholders, and these are also being considered in the lifetime of the project. The potential beneficiaries, and the ways in which they will gain from the research, are as follows:

- Industry: which will gain, in the short term, from new knowledge on the contents of waste and a clearer picture of the UK's potential for in situ recovery from the typology of sites. Ultimately, it could gain economic advantage from turning waste into an asset by transforming them into viable ore deposits.

- Repository owners: who could gain economically from: new funding streams generated by recovered resources; more rapid reclamation (i.e. turnover) of sites; and reducing future liabilities (i.e. potential costs) (in the medium-long term) thereby allowing improved management of repositories all of which, as noted by a project partner, has the potential for 'substantial benefit both in terms of the long-term site stewardship and reduction in fugitive emissions'.

- Engineers and other professionals engaged with waste repositories: who will gain marketable knowledge, and advanced tools (e.g. the Resource Recovery model), to deal with waste (in the short-medium term).

- Regulators and policy makers: who will be able to develop more effective policies and regulations, by being equipped with better understandings (and evidence) of impacts of interventions in waste deposits, and new techniques to identify effective and socially acceptable recovery (in the short-medium term).

- Residents and communities (in proximity to sites and transportation routes), who, in the longer term, will avoid disruption because in situ techniques have less impact than ex situ extraction and other forms of repository mining, and who will benefit from the removal of hazardous components of waste deposits (in the medium-long term).

- Broader society: which will have more secure access to resources, reduced environmental and landscape impacts (because of reduced mining of virgin ores), more waste 'reuse' (rather than disposal), and hence enhanced recycling with the reduced need for geological disposal (in the medium-long term).


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Muaaz-Us-Salam S (2019) The case for examining fluid flow in municipal solid waste at the pore-scale - A review. in Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA

Description > We have formulated a nw concept in recovering metals from wastes, effluents and ores which we have termed "precision mining", we demonstrated the concept by selective recovery of copper from metal-bearing effluents using nanzerovalent iron (nZVI) supported on diatomite > We have demonstrated the selective recovery of rare earth elements, copper and nanoparticulate copper from metal-bearing effluents using nZVI > We have estimated the resource potential of many of the UK's largest former metal mine sites, and shown how this only one dimension of value that has to be considered against many other positive and negative value attributes for these mine sites > We have developed our own methods for digestion and analyses of wastes and rock materials for Rare Earth Element Analyses > We have developed the application of more environmental friendly lixiviants for use in leaching of waste piles >We have demonstrated the application of electrokinetics for metal recovery from wastes >We have demonstrated that many iron oxide-rich wastes contain microbial populations which could be stimulated in situ to enhance the recovery of metals from those wastes
Exploitation Route All of the research highlights mentioned above have application for other researchers and.or by industry and we are actively pursuing many lines of follow-up which I hope to be able to report on fully after the grant finishes in early 2019.
Sectors Environment,Manufacturing, including Industrial Biotechology,Culture, Heritage, Museums and Collections

Description There are several promising lines of impact developing which are still at an early stage but that I hope to be able to report on fully at the next submission.
Title Mine waste composition dataset 
Description The data comprises of geochemical characterisation of mine wastes from 11 sites across South West England and Wales. 
Type Of Material Database/Collection of data 
Provided To Others? No  
Impact Publications in preparation. 
Description EURELCO 
Organisation European Enhanced Landfill Mining Consortium
Country Belgium 
Sector Charity/Non Profit 
PI Contribution We joined the EURELCO (European Enhanced Landfill Mining Consoritum) before this award but have continued to actively participate at meetings and conference and are looking at putting in an MSCA-ETN bid in collaboration with KU Leuven and UGent through these activities.
Collaborator Contribution Promoting/ diseminating the work of the INSPIRE project within the consortium and more widely.
Impact 3 x conference publications at the 3rd Enhanced Landfill Mining Symposium Lisbon, 2016 see:
Start Year 2015
Description Minea 
Organisation European Cooperation in Science and Technology (COST)
Department COST Action
Country Belgium 
Sector Public 
PI Contribution Peter Cleall is a Management Committee member for UK on this COST Action
Collaborator Contribution Development of collaborative opportunities
Impact n/a
Start Year 2016
Description INSPIRE Stakeholder Meeting 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact INSPIRE stakeholder meeting - presentations followed by "speed dating" presentation format with project partners and new potential stakeholders
Year(s) Of Engagement Activity 2016
Description Materials World Article 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Media (as a channel to the public)
Results and Impact Media article

Year(s) Of Engagement Activity 2014
Description Natural Resources Wales Mine Exchange Event 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Invited presentation at the Natural Resources Wales Mine Exchange Event specificaly to talk about the INSPIRE project an opportunities for resource recovery from mine wastes
Year(s) Of Engagement Activity 2017
Description Presentation at Resource Recovery from Waste Programme Event 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact INSPIRE presentation as part of the presentation and workshop event organised by the Resource Recovery from Waste Programme in Leeds
Year(s) Of Engagement Activity 2016
Description Project Conference 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact This was a conference/CPD event to mark the end of three years of our INSPIRE project. It contained 4 sessions, the first session was the PI describing the context of the project and its broad implications, followed by a speaker from the KU Leuven who spoke on behalf of the European Enhanced Landfill Mining Consortium (EURELCO) to give the European context for the research. Session 2 was a series of technical sumaries of project findings from work packages leaders. Session 3 was a feedback and feedforward session where invitees where asked specific questions on practical implementation of the research findings and where the research could develop in the future, or where there were technologies to be developed. The last session was a project pitching session for a follow up research bid which is under preparation.
Year(s) Of Engagement Activity 2017
Description Project partner meeting 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Participants in your research and patient groups
Results and Impact Meeting with NERC project partners and also a newly established project partner. The first part of the meeting was to bring the project partners up to date with the project and listen to their technical views and the second half of the meeting was dedicated to a workshop run by Prof Katie Williams (UWE) to draw out how the partners thoughts on subjects such as how they could contribute to the project, how they wanted to interact with the project and how the project could maximise impact.

Project partners invited the team to provide specific requests for different samples for the research
The meeting has prompted project partner Prof Paul Phillips to make links with Azerbaijan to look for possible joint collaboration.
Year(s) Of Engagement Activity 2014
Description Science at the Assembley 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Policymakers/politicians
Results and Impact Presentation stand manned by Dr Harbottle and Mahdi
Year(s) Of Engagement Activity 2015