Use of low cost combustible materials in cupola melting

In order to reduce the consumption of (high quality) coke, techniques have been developed to allow the use of high calorific value solid waste and lower grade coke as a fuel. 

A particular type of cupola, named the FAR furnace, has been developed in Brazil, that allows the melting of a conventional charge using tyres and plastic pieces (automotive shredder residue - ASR, fluff, etc.), mixed with second rate coke. The cupola structure is totally different from the conventional one. Only the metallic charge enters from the top. The solid fuel is fed in fi-om the side, so that it reaches the hot zone very quickly. Here hydrocarbons are cracked and combusted. 

Alternative injection systems allow the addition of fluff or dust directly through the tuyeres or by using specific injectors. 

A reduction in the consumption of cokes, as they are replaced by solid waste (ASR, fluff), which is difficult to treat in conventional combustion systems. 

For the FAR furnace, the best results have been obtained using 35 % fluff and 65 % coke. This technique has been developed up to pilot scale. 

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