The disposal of foundry sand used in single-use casting has been one of the biggest challenges and problems for foundries. As a rule of thumb, the amount of waste sand generated in a foundry is roughly the same as the amount of finished cast products produced. And that is a lot! There are several sand recycling methods but, unfortunately, they are not widely used in the foundry industry due to high investment costs and the insufficient capacity of most methods. Because of this, Finn Recycling Oy wanted to develop its own unique technique called ‘sand regeneration’.
Our goal and mission is to develop new and innovative solutions which will increase the reuse of minerals and reduce the need to use virgin raw materials. An environmentally friendly and sustainable casting process benefits us all, which is why we need various constantly developing solutions that allow us to take the recycling of waste sand as far as possible.
Virgin Raw Materials Can Be Replaced with Treated Sand
Even though significant amounts of recycled metals are being used as raw material in the foundry industry, the sand used as mold material is almost always a virgin raw material. This virgin sand is imported from abroad, shipped to Finland, delivered to the customer by truck, and disposed of to landfill after the foundry process. This process puts a huge burden on the environment, but it can now be replaced by using regenerated sand: The sand is transported from a foundry to the regeneration plant for treatment and then back to foundries, industrial facilities, or power plants where it can be reused as new raw material, for example.
If the entire foundry industry in Finland switched to thermal regeneration, we could reduce CO2 emissions by more than 13 million kilos. This translates to more than 140 trips to the Moon and back by car!
If surplus foundry sand is not recycled, it is disposed of as waste in landfills due to the insoluble binders it contains. In the regeneration process, binders are removed from the sand, after which the sand can be reused, and because the amount of waste is significantly reduced, foundries can save money on sand. All this naturally also saves the Earth’s limited resources when the need to excavate virgin silica sand declines.
Putting Mineral Side Streams to Use
Mineral materials are solid chemical compounds that occur in pure deposits in nature. Oxides, silicates, and carbonates are some examples of these mineral materials found in nature. Many of these compounds can also be manufactured, and industrial processes, such as metal recovery processes, alter the composition of mineral materials. Mineral materials are used unprocessed in different industries (fluidized bed processes, cutting processes, water treatment, construction industry) as well as processed with different types of binders (foundry industry, construction industry). On the other hand, industrial applications also produce a significant amount of mineral side streams which are either disposed of as waste or used as construction fill.
The goal of Finn Recycling Oy is to use new innovations to develop new methods for using mineral side streams in industrial applications. This would help us replace industrially manufactured synthetic and often imported materials. At the same time, we could commercialize new products based on circular economy and develop new business opportunities.
Finn Recycling Oy develops clean recycling solutions for energy, foundry, and waterjet cutting industries. Clean solutions, or cleantech, refer to products, services, processes, and entire concepts that promote the sustainable use of natural resources and reduce emissions. Clean solutions respond to global environmental challenges such as environmental pollution, climate change, and resource sufficiency. At the same time, they increase industrial competitiveness thanks to the more efficient use of materials, energy, and other resources.
Our ongoing experiments, learning experiences, and development projects have helped us set a significant example of an industrial symbiosis. This allows us to do our part to support sustainable development and reduce our burden on the environment.