Keywords: granulated nickel slag, utilisation, eco-efficiency, industrial ecoparks, by-products, industrial ecology, slag modification
Towards eco-efficiency: granulated nickel slag's transformation into a product
The granulated nickel slag is the biggest unexploited solid side stream formed in the area of the Harjavalta industrial ecopark in south-west Finland. Nowadays one-quarter of the granulated nickel slag is utilised in the sand blasting and roofing felt industries and three-quarters are still dumped in landfills. At the moment the main obstacles to a wider utilisation of granulated nickel slag are the environmental properties of slag and fluctuations in its composition, which lead to changes in the slag's stability. Despite the obstacles, there are possibilities to promote slag utilisation. A possible way to affect slag properties is through slag modification by immobilising harmful elements in the slag. Also, the determination of environmental and technical properties of slag plays an important role in the utilisation aims. The utilisation of slag is one way to support the eco-efficiency of the Harjavalta industrial ecopark. Slag can be used in other applications as a raw material or as a product instead of natural raw materials.