R3AW: Resource Recovery and Remediation for Alkaline Wastes

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.

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.