On 18 May 2022, NEMO organised a clustering workshop on multi-criteria assessment as a parallel session in the “(Re)Mining extractive waste, a new business?” symposium in Mechelen, Belgium. More than 30 participants interacted through role-playing and lively discussions, aiming to elucidate the many challenges in integrating techno-economic, environmental and social concerns related to reprocessing of mining waste.
The workshop started with two keynote presentations to introduce the topic.
Dr. Stéphanie Muller from BRGM (France) showed how a combination of tools could be used to obtain comprehensive sustainability assessments for mining activities. Such assessments must answer questions the decision-maker raises and are always context-dependent. Engineering tools are particularly promising when used in combination with Environmental-Life Cycle Assessement (E-LCA) to access reliable and location-specific data (e.g. reactive transport modelling) or support investment decisions (e.g. process simulation). Social-Life Cycle Assessment (S-LCA) is a way to introduce the social aspects into decision-making through the LCA framework.
Prof. Sue Harrison from the University of Cape Town (South Africa) stressed that responsible mining should combine three goals: i) maximise economic value, ii) minimise long term (environmental) liability and iii) maintain or improve quality of life and livelihoods. Analytical tools such as techno-economic analysis, E-LCA and S-LCA can be used to support these goals and depend strongly on in-depth characterisation and analysis. She introduced a framework for (re)mining solutions consisting of 1) waste characterisation, 2) technology selection, 3) process flow sheet, 4) decision framework, 5) proof of concept. Early assessment of potential flowsheets is critical to allow process adjustment without excessive costs. Finally, life after the mine should be centre-stage – communities often develop around mines, and their fate after mining operations cease should be considered early on.
A role-play exercise was set up to introduce the participants to the complexity of multi-stakeholder decision-making. Participants were assigned the roles of mining companies, civil society/NGOs, local community, end consumers, government or value chain actors. They were then asked to debate about a case study where they had to choose between remining, mine closure or new mine exploitation.
The discussions showed that trust is crucial! Unfulfilled promises are detrimental to trust for future operations. Lack of trust in government, even in Europe, induces citizens to be involved personally instead of relying on the regulatory systems in place. Early and transparent communication and demonstration of projects may help to increase trust.
Future generations must be considered when making a decision. What will be left for them in terms of both valuable resources and environmental or social liabilities? Participants agreed that local communities should be meaningfully involved early in the project due to the severe impact (re)mining operations may have on their life and living conditions. They should receive sufficient information and participate in the decision-making process, just like the Aarhus Convention stipulates, for example, concerning environmental matters.
There was disagreement among the participants about who has to make the final decision, should it be the public authority? Mining companies? Local municipalities?. It was suggested that some inconvenience (at the local level) should be tolerated if it will lead to long term substantial benefits (for society as a whole). But it was recognised that it is difficult to draw the line between what is an acceptable burden for a local community, and there is also the question of who has the right to draw this line? It was suggested that the local communities need to have the right to say yes or no to projects that will take place on their grounds.
Mining companies are facing increasing consumer demands for better environmental and social standards, while competing in a global market. Companies need to take responsibility for their operations impacts and generated waste. Governments must assume the responsibility of following up mining operations and waste, also on historical sites, ensuring that environmental concerns are addressed in the short and the longer term, and providing incentives where necessary.
The suggestion was made that the EU could set up a company responsible for remining all over Europe, following the example of Chile. However, the complexity of decision-making at EU level raises doubts regarding the feasibility thereof. Furthermore, there is no “one size fits all” solution, and site-specific development and expertise will always be needed. Ideally, an independent consultancy firm could be set up that supports mining companies.
The decision on whether or not to (re)mine should take into account not only the economic aspects but the impact on the environment and local populations in the long term. Overall, it is felt that we should move beyond avoiding negative impacts (e.g. pollution), which can be seen as a minimum requirement, but should focus on establishing a net gain. It is important that local communities are early involved in the projects and that have a real share of the benefits from the (re)mining project, by job creation and better living conditions, for example.
After the discussions, dr. Andrea di Maria (KU Leuven) presented the multi-criteria assessment results of NEMO. This assessment provides feedback to the NEMO researchers on key impacts and potential improvements. The impact of the technologies, mainly related to the use of electricity and chemicals, should be offset against the potential gains by replacing primary raw materials extraction. It is clear that the NEMO technologies need further improvement and upscaling to ensure the net impact is positive.
In conclusion, the presentations and discussions showed that integrating the results of different assessments is difficult, and the relative importance of economic, environmental and social factors differs strongly among stakeholders. While techno-economic and environmental analysis tools are quite standardised and broadly used, social assessment tools, like S-LCA, for example, are less mature. Moreover, social assessment is, per definition, site-specific, requiring interaction with local people and the use of qualitative indicators together with the quantitative ones. Therefore, integrating results from different assessments remains a challenge, but at the same time, it offers the potential benefit of a more sustainable and holistic approach.