Gransil - construction aggregate made from sewage sludge and mineral waste
Gransil is an innovative, ecological and durable construction aggregate, where for the production, there were used waste materials. The NTI company implemented a technology where only waste materials are used. The materials are sludge from wastewater treatment, mineral waste from ashes after burning solid fuels and ashes after the combustion of sewage sludge. It is also possible to include glass waste from under-sieve fraction and cullet. It is estimated to acquire 40 000 t of Gransil, there is needed 33 000 t of sludge and 33 000 t of mineral waste. The technology bases on simple line: acceptance of raw materials, storage, preparation of the input and sintering.
The material can be used in geotechnics, construction and gardening.

Resources needed


Evidence of success

Gransil product fulfill the requirements of ISO 9001:2015.
Annual aggregate production at 35 000 - 40,000 t
Project started in 2013 when factory was build and in 2016 production started.

Difficulties encountered

The company is still exploring possibilities of using new type of wastes in the method.

Potential for learning or transfer

Market benefits of applying the technology:
● Due to its unique characteristics, the aggregate is a huge competition for natural products such as expanded clay.
● The technology is waste-free and energy-saving - pure recycling! The product is obtained by the method of obtaining lightweight aggregates through the management of sewage sludge and mineral waste.
● It is possible to manufacture it with specific defined by the recipient properties such as: grain size, color, crushing strength, bulk density, absorbability, frost resistance, thanks to the use of various types of raw materials with specific properties and controlling their mass share in the production process.
● The aggregate created in the process is characterized by the lack of heavy metal leaching, because they are permanently built into the aggregate structure.
Main institution
Dolnośląskie, Poland (Polska)
Start Date
January 2013
End Date


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