R3AW: Resource Recovery and Remediation for Alkaline Wastes

Lead Research Organisation: University of Hull
Department Name: Biological Sciences


Highly alkaline (i.e. bleach-like) wastes are produced in large quantities by various globally important industrial processes. For example, up to 180 million tonnes of slags are produced each year by the steel industry, while up to 120 million tonnes of bauxite processing residue (from aluminium refining) are generated globally. Traditionally, these wastes have simply been dumped into landfill sites, and pose significant environmental risks. For example, water percolating through the landfill to form "leachate" is toxic to aquatic life, and dust generated from landfill activity can pose public health hazards. On the other hand, these wastes can also provide potential resources we would like to recover. Global mineral and metal prices are high, and there is renewed interest in recovery of metals from any available source. This is particularly the case for those metals important for technological applications, such as vanadium for high grade steel manufacture and rare earth elements for "hi-tech" applications such as visual displays, computer memory and green technologies such as wind turbines and hybrid cars. The potential of highly alkaline waste for metal recovery is enormous; not only is waste produced in large amounts every day, but there is up to 100 years of "legacy" stockpiles in some areas. Unfortunately, the concentration of metals within the leachate is low, and recovering metals from it would be expensive. Directly digging up legacy sites is feasible, but is also expensive and would cause a lot of environmental disturbance. Recent ground-breaking work by the project team has shown that we can accelerate natural weathering processes of steel industry residues by covering it with compost. This concentrates metals like nickel and vanadium to recoverable concentrations in the leachate with almost no physical disturbance. Covering the waste material in compost will also reduce - potentially prevent - dust generation. The compost used in these experiments is "municipal organic waste" that is mostly put into landfill today, so the treatment can be done at almost no financial cost and with a knock-on environmental benefit. If this were not enough, the compost allows more dissolved CO2 to penetrate into the waste material where it reacts with the metals to form carbonate minerals. This is an important means of carbon sequestration, which will offset some of the emissions from the industry. Further deposition of carbonate minerals can be encouraged within the leachate itself once it reaches surface, sequestering even more carbon and consuming some of the low value metals in the leachate it would be worthwhile to recover.

As ever, there remain considerable economic, legislative, environmental and social issues that need to be addressed to ensure the responsible development of this kind of industry as well as a range of scientific challenges we still need to address. R3AW aims to address these challenges by bringing together key commercial partners (e.g. steel, cement and alumina industries) with a multi-disciplinary team of environmental scientists, waste policy experts and experts in systems analysis and stakeholder engagement to pave the way to transform resource recovery and environmental remediation in the steel and cement industries and elsewhere. Our objectives for the project are:
1) Develop an interdisciplinary approach involving researchers and all other stakeholders to identify key scientific, economic and societal needs and questions surrounding resource recovery from caustic waste streams.
2) Undertake preliminary assessment of the accelerated leaching approach we are pioneering under field conditions in the UK.
3) Determine the critical scientific, industrial, societal and policy issues currently limiting application of this highly promising science in a manner that can be addressed in future government and industrially funded projects.
4) Develop full research proposals to address these questions.

Planned Impact

The new combined environmental science and systems-based methodology proposed here is (to our knowledge) completely novel. In addition to providing a means to maximise the impact of R3AW - ensuring the research is USEFUL and will be USED - it will set a new standard for stakeholder engagement for projects where novel science is applied to solve important environmental and industrial problems. The impact of the project may primarily lie outside of any new technologies we deliver for the steel and allied industries.

Whole systems impact
The proposal will concurrently reduce the adverse impacts of, and create new benefits from the economic, environmental and social outcomes of:
- Currently unusable organic waste sent to landfill
- Industrial carbon emissions
- Hyperalkaline and heavy metal containing water residues
- Post production wastes
by understanding that these are not four separate issues, but four interdependent components of a single whole system.
The route to impact has three key premises underpinned by rigorous stakeholder engagement:
1. A whole systems approach developed to provide a framework for understanding, addressing and implementing environmental science and technologies in commercial and social contexts.
2. The preliminary environmental science advances of the team, including an existing industrial trial with Tata Steel.
3. Development and implementation of the combined systems and environmental science methodology across the steel, cement and allied industries.

Workplan for impact:
Whilst definite systems level stakeholder identification and engagement is a core part of the proposal, the stakeholders already identified and potential benefits to each group are summarised below:

Academic Organisations: HEIs in the networks; NERC; KTNs: Environmental Sustainability & Energy Generation & Supply; CO2Chem Network
Impacts: Relationship building and knowledge exchange; Credible opportunities for securing funding; Development of systems approach tailored to deliver 'impact' from environmental R&D.

Business Organisations: e.g. Tata Steel Europe; MIRO; steel, cement, allied industries; landfill sites; KTNs
Impacts: Increased productivity from resource recovery; Reduced CO2 emissions and environmental remediation costs; Enhanced ecosystem services; Enhanced environmental reputation; New technologies for high-value mineral recovery.

Environmental and wildlife organisations: e.g. Natural England; Wildlife Trusts; RSPB
Impacts: New tools for working with industry to protect the environment; direct partnership with industry stakeholders and input into industrial developments

Government & Policy Organisations: Government (national & local, inc. DEFRA & Environment Agency); Local Nature Partnerships.
Impacts: Contribution to CO2 reduction and environmental enhancement/protection targets; enhanced stakeholder interaction methods; Enhanced UK competitiveness of key industries; New policy input.

Societal Organisations: Local communities; Recreational/tourism orgs. (e.g. Angling Trust)
Impacts: Reduced environmental risk and enhancement of, tourist environments (e.g. rivers); Increased profitability of key employers; Enhanced natural environment; Greater participation local decision making.

Methods for delivering impact:
Workshops. Through working together, stakeholders will come to understand how their needs, issues and perspectives impact on, and are impacted by, those of others.

Network activities. The environmental science and systems results will be disseminated through the new networks, which will also produce future funding proposals.

PR. The results will be publicised in appropriate public and trade media to reach a wider audience and so promoting collaborations and enhancing future impact.


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Anton ÁD (2014) Geochemical recovery of the Torna-Marcal river system after the Ajka red mud spill, Hungary. in Environmental science. Processes & impacts

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Gomes HI (2017) Hydraulic and biotic impacts on neutralisation of high-pH waters. in The Science of the total environment

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Gomes HI (2016) Vanadium removal and recovery from bauxite residue leachates by ion exchange. in Environmental science and pollution research international

Description The aim of the catalyst grant was to undertake preliminary laboratory and field work alongside networking activities to support the full development of a research proposal to find novel ways to recover valuable metals from industrial by-products.
Our work showed that a simple compost cover over alkaline wastes can increase the rates at which valuable metals flow from the wastes. The work also suggested that the process was quicker biological activity than without. This raises the prospects for being able to 'bio-mine' valuable metal resources such as vanadium, chromium and rare earths that are in short supply globally and crucial to future green technologies. The fact that many of these elements can also be toxic in the environment means that if we can recover the metals, we are also minimising the long term environmental impacts of globally important industrial by-products such as steel slags and red mud from alumina manufacture.
We also undertook some additional baseline characterisation of legacy industrial waste sites to assess (a) resource recovery potential, and (b) assess environmental impacts.
We developed a research consortium of academic (Hull, Leeds, Newcastle, Cardiff, Huddersfield) and industrial partners (Tata, Rio Tinto, CL:AIRE, Link2Energy, the UK Quality Ash Association, the Mineral Industry Research Organisation) for the full proposal.
Exploitation Route The findings have been taken forward to a funded NERC/ESRC project in collaboration with the industrial partners listed above.
Sectors Energy,Environment,Other

Description The findings have been used to secure a full ESRC/NERC grant under the Resource Recovery from Waste programme.
First Year Of Impact 2014
Sector Environment
Impact Types Societal,Economic

Description Resource Recovery and Remediation of Alkaline Wastes
Amount £1,100,000 (GBP)
Funding ID NE/L014211/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 09/2014 
End 09/2017
Description British Steel 
Organisation Tata Steel Europe
Country United Kingdom 
Sector Private 
PI Contribution Monitoring and advising on leachate management
Collaborator Contribution Facilitating site access. Construction of pilot leachate management facility.
Impact Ongoing advise on environmental management.
Start Year 2013
Description Limerick, Ireland 
Organisation University of Limerick
Country Ireland 
Sector Academic/University 
PI Contribution Dr WM Mayes acted as technical reviewer of pilot scale bioremediation system for highly alkaline red mud leachate. Discussions as part of the formation of a consortium, BRAVO, recently recognised as a Raw Materials Commitment (RMC) by the High Level Steering Group of the European Innovation Partnership.
Collaborator Contribution Discussions as part of the formation of a consortium, BRAVO, recently recognised as a Raw Materials Commitment (RMC) by the High Level Steering Group of the European Innovation Partnership.
Impact Consortium recognised as a Raw Materials Commitment (RMC) by the High Level Steering Group of the European Innovation Partnership. The partnership is multi-disciplinary: chemical engineering, geotechnical experts, environmental geochemists, ecologists, materials scientists.
Start Year 2014
Description Rio Tinto Global Legacy 
Organisation Rio Tinto Alcan
Country Canada 
Sector Private 
PI Contribution Work on red mud management improving body of knowledge for practical bauxite residue disposal area management
Collaborator Contribution Discussions on applications of research. Discussions on future research developement
Impact None yet
Start Year 2014
Description Newcastle seminar 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact Seminar on project: Alkaline residues and the environment: impacts and opportunities
Year(s) Of Engagement Activity 2016
Description OU Seminar 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Other audiences
Results and Impact Invited seminar at Open University
Year(s) Of Engagement Activity 2016