Circular economy means ensuring a sustainable use of the Earth’s resources – among other things because recycling benefits the environment and reduces the number of raw materials we need to mine. However, there are still large raw material losses in the circular material cycle. This is due to both a lack of knowledge about which materials are in the items we discard, and a lack of technological solutions to extract them.
Developing the circular economy requires knowledge and skills related to society’s and companies’ material flows.
Material flow analyses
The waste’s path from collection to recycling is long – and often gets lost in the unknown when the waste is exported. MiMa therefore maps what happens to the waste and examines how well it is recycled.
In order to assess whether and how the raw materials in the waste can be utilised, it is necessary to characterise the composition of the waste and the number of raw materials. MiMa has access to laboratory facilities for chemical and mineralogical characterisation (including XRD, EDS, SEM) and to resource geologists’ special knowledge of materials.
MiMa carries out market research to identify opportunities and limitations for a valuable recycling of the raw materials and to ensure that the raw materials are not downgraded.
MiMa looks at anthropogenic resources and examines whether it is possible to increase the value of recycling even more – an activity that is also known under the term urban exploration.
About circular economy
The circular economy and its leaks. Modified after figure by the European Commission.
The raw materials in the waste
The raw materials in the man-made waste streams are also called anthropogenic resources. In Denmark, several million tonnes of anthropogenic resources are produced every year. A significant part of them is utilised by source sorting. However, there is a large untapped potential, as there is very little knowledge about the chemical composition of these raw materials. Correspondingly, there is very little knowledge about the resource potential in old landfills.
Some types of waste are particularly challenging to recycle because they have a very heterogeneous chemical composition and often consist of components of many different sizes mixed together – from microscopic dust grains to large pieces and lumps. Concrete examples of these types of waste are slag and ash from waste incineration, sludge from wastewater treatment, dust from industry and road sweeping, construction waste, surplus soil and contaminated soil.
The challenge is to get metals and minerals recycled so that they remain in a circular material cycle and are not downgraded to e.g. fillers and soil layers.
Extraction of the raw materials in society’s waste is often referred to as ‘urban mining’. There are many similarities between urban mining and mining. Among other things, it is necessary to first determine:
- the content of raw materials that can be mined
- how to get them out
- the amount
- the cost.
Effective urban mining is difficult due to the complex composition of the materials; it is therefore typically easier to extract the raw materials by ordinary mining. With a growing focus on recycling and circular economy, urban mining is an area where new solutions and technologies will grow in the coming years.