India is the world's largest Sponge Iron producer and mostly uses the Coal based process. The down-side of this industry is that it generates significant amounts of solid waste in the form of ESP Flyash and Bag House Filter Dust. Now as this Flyash contains considerable unburned carbon ( 10% and above), it cannot be utilized in cement manufacturing. Likewise the Bag Filter dust contains upto 25% unburned carbon and above 70% ash which again doesn't allow it to be reused viably as a fuel. Meanwhile, reducing the carbon content by the Carbon-burnout method is too expensive and polluting just to convert the wastes into usable Flyash.
As a result most of these wastes go into landfill, where they again contribute to ground and water pollution.
Surprisingly there are technologies which can not only effectively convert these wastes into usable items like recovered fuel and low carbon Flyash, but at the same time clean up the environment and save the companies great expenses. Its is called Carbon-Ash Separation and there are several ways of doing the same.